Search results for: heterotrophic aerobic bacteria (HAB)

Authors: Stephen Olusanmi Akintayo, Ilesanmi Fadahunsi

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The ability of Lactic acid bacteria (LAB) to grow and survive in milk is being exploited in industrial and biotechnological applications. Although considerable studies have been reported on the fermentation of milk, however, not so much work has been documented on the selection of LAB strains from milk of the Nigerian local cattle breeds for their starter culture potentials. A total of 110 LAB were isolated from raw milk of Sokoto gudali cattle breed. The isolates were screened for their proteolytic activities on skimmed milk media with isolates A07, F06 and A01 showing the highest zone of clearance of 18.5mm, 18.5mm, and 18.0mm respectively and were selected for the studies of their growth in different constituents of milk. A01, F06, and A07 were identified as Pediococcus acidilactici, Lactococcus raffinolactis, and Leuconostoc mesenteriodes respectively using cultural, biochemical, physiological and molecular characterization techniques. Leuconostoc mesenteriodes showed the highest growth in all the milk components that were used in this study. The three LAB species selected showed a growth range of 6.46 log cfu/ml to 10.91 log cfu/ml in lactose with Leuconostoc mesenteriodes showing the highest growth of 10.91 log cfu/ml while Pediococcus acidilactici recorded the lowest growth of 9.78 log cfu/ml. In medium containing leucine as the only amino acid, the viable counts of Pediococcus acidilactici, Lactococcus raffinolactis and Leuconostoc mesenteriodes in log cfu/ml at zero hour were 6.39, 6.36 and 6.38 respectively which increased to 9.31 log cfu/ml, 9.21 log cfu/ml, 9.92 log cfu/ml respectively after 24 hours. Similarly, in all other substrates (casein, lysine, glutamic acid, aspartic acid, stearic acid and oleic acid ) tested in this study, Leuconostoc mesenteriodes showed the highest growth. It was observed that the highest quantity of lactic acid (15.31mg/ml) was produced by Leuconostoc mesenteriodes. The same trend was also observed in the production of diacetyl and hydrogen peroxide by the three tested microorganisms. Due to its ability to grow maximally in milk components, Leuconostoc mesenteriodes shows potential as starter culture for milk fermentation.

Keywords: Leuconostoc mesenteriodes, lactic acid bacteria, Sokoto gudali, starter culture

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Authors: C. Miranda, S. Cunha, R. Soares, M. Maia, G. Igrejas, F. Silva, P. Poeta

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The worldwide inappropriate use of antibiotics has increased the emergence of antimicrobial-resistant microorganisms isolated from animals, humans, food, and the environment. To combat this complex and multifaceted problem is essential to know the prevalence in livestock animals and possible ways of transmission among animals and between these and humans. Enterococci species, in particular E. faecalis and E. faecium, are the most common nosocomial bacteria, causing infections in animals and humans. Thus, the aim of this study was to characterize resistance and virulence factors genes among two enterococci species isolated from calf colostrums in Portuguese dairy farms. The 55 enterococci isolates (44 E. faecalis and 11 E. faecium) were tested for the presence of the resistance genes for the following antibiotics: erythromicyn (ermA, ermB, and ermC), tetracycline (tetL, tetM, tetK, and tetO), quinupristin/dalfopristin (vatD and vatE) and vancomycin (vanB). Of which, 25 isolates (15 E. faecalis and 10 E. faecium) were tested until now for 8 virulence factors genes (esp, ace, gelE, agg, cpd, cylA, cylB, and cylLL). The resistance and virulence genes were performed by PCR, using specific primers and conditions. Negative and positive controls were used in all PCR assays. All enterococci isolates showed resistance to erythromicyn and tetracycline through the presence of the genes: ermB (n=29, 53%), ermC (n=10, 18%), tetL (n=49, 89%), tetM (n=39, 71%) and tetK (n=33, 60%). Only two (4%) E. faecalis isolates showed the presence of tetO gene. No resistance genes for vancomycin were found. The virulence genes detected in both species were cpd (n=17, 68%), agg (n=16, 64%), ace (n=15, 60%), esp (n=13, 52%), gelE (n=13, 52%) and cylLL (n=8, 32%). In general, each isolate showed at least three virulence genes. In three E. faecalis isolates was not found virulence genes and only E. faecalis isolates showed virulence genes for cylA (n=4, 16%) and cylB (n=6, 24%). In conclusion, these colostrum samples that were consumed by calves demonstrated the presence of antibiotic-resistant enterococci harbored virulence genes. This genotypic characterization is crucial to control the antibiotic-resistant bacteria through the implementation of restricts measures safeguarding public health. Acknowledgements: This work was funded by the R&D Project CAREBIO2 (Comparative assessment of antimicrobial resistance in environmental biofilms through proteomics - towards innovative theragnostic biomarkers), with reference NORTE-01-0145-FEDER-030101 and PTDC/SAU-INF/30101/2017, financed by the European Regional Development Fund (ERDF) through the Northern Regional Operational Program (NORTE 2020) and the Foundation for Science and Technology (FCT). This work was supported by the Associate Laboratory for Green Chemistry - LAQV which is financed by national funds from FCT/MCTES (UIDB/50006/2020 and UIDP/50006/2020).

Keywords: antimicrobial resistance, calf, colostrums, enterococci

Procedia PDF Downloads 198

Authors: Włodzimierz Przewodowski, Agnieszka Przewodowska

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Colloidal metal nanoparticles have drawn increasing attention in the field of phytopathology because of their unique properties and possibilities of applications. Their antibacterial activity, no induction of the development of pathogen resistance and the ability to penetrate most of biological barriers make them potentially useful in the fighting against dangerous pathogens. These properties are very important in the case of protection of strategic crops in the world, like potato - fourth crop in the world - which is host to numerous pathogenic microorganisms causing serious diseases, significantly affecting yield and causing the economic losses. One of the most important and difficult to reduce pathogen of potato plant is quarantine bacterium Clavibacter michiganensis ssp. sepedonicus (Cms) responsible for ring rot disease. Control and detection of these pathogens is very complicated. Application of healthy, certified seed material as well as hygiene in potato production and storage are the most efficient ways of preventing of ring rot disease. Currently used disinfectants and pesticides, have many disadvantages, such as toxicity, low efficiency, selectivity, corrosiveness, and the inability to eliminate the pathogens in potato tissue. In this situation, it becomes important to search for new formulations based on components harmful to health, yet efficient, stable during prolonged period of time and a with wide range of biocide activity. Such capabilities are offered by the latest generation of biocidal nanoparticles such as colloidal metals. Therefore the aim of the presented research was to develop newly antibacterial preparation based on colloidal metal nanoparticles and checking their influence on the Cms bacteria. Our preliminary results confirmed high efficacy of the nano-colloids in controlling the this selected pathogen.

Keywords: clavibacter michiganensis ssp. sepedonicus, colloidal metal nanoparticles, phytopathology, bacteria

Procedia PDF Downloads 272

Authors: Diafat Abdelouahab, Ekhalfi A Hammoudia, Meribai Abdelmalek A, Bahloul Ahmedb

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The present study aimed to characterize 30 honey samples from the Bordj Bou Arreridj region (Algeria) regarding their floral origins, physicochemical parameters, mineral composition and microbial safety. Mean values obtained for physicochemical parameters were: pH 4.11, 17.17% moisture, 0.0061% ash, 370.57μS cm−1 electrical conductivity, 21.98 meq/kg free acidity, and 9.703 mg/kg HMF. The mineral content was determined by atomic absorption spectrometry. The mean values obtained were (mg/kg): Fe, 7.5714; Mg, 37.68; Na, 186,63; Zn, 3,86; Pb, 0,4869 × 10-3 ; Cd, 267 × 10-3. Aerobic mesophiles, fecal coliforms and sulphite-reducing clostridia were the microbial contaminants of interest studied. Microbiologically, the honey quality was considered good and all samples showed to be negative in respect to safety parameters. The results obtained for physicochemical characteristics of Bordj Bou Arreridj honey indicate a good quality level, adequate processing, good maturity and freshness.

Keywords: pollen analysis, physicochemical analysis, mineral content, microbial contaminants

Procedia PDF Downloads 89

Authors: V. N. Chebotkevich, E. E. Schetinkina, V. V. Burylev, E. I. Kaytandzhan, N. P. Stizhak

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Objective: Blood stream infections (BSI) are severe, life-threatening illness for immuno compromised patients with hematological malignancies. We report the trend in blood-stream infections in this group of patients in the period 1991-2013. Methods: A total of 4742 blood samples investigated. All blood cultures were incubated in a continuous monitoring system for 7 days before discarding negative. On signaled positive, organism was identified by conventional methods. The Real-time polymerase chain reaction (PCR) was used for the indication of human herpes virus 6 (HHV-6), Cytomegalovirus (CMV) and Epstein-Barr virus (EBV). Results: Between 1991 and 2001 the incidence of Gram-positive bacteria (Staphylococcus epidermidis, Staphylococcus aureus) being the most common germs isolated (70,9%) were as Gram-negative rods (Escherichia coli, Klebsiella spp., Pseudomonas spp.) – 29,1%. In next decade 2002-2012 the number of Gram-negative bacteria was increased up to 40.2%. It is shown that the incidence of bacteremia was significantly more frequent at the background of detectable Cytomegalovirus and Epstein-Barr virus-specific DNA in blood. Over recent years, an increased frequency of micro mycetes was registered in blood of the patients with hematological malignancies (Candida spp. was predominant). Conclusion: Accurate and timely detection of BSI is important in determining appropriate treatment of infectious complications in patients with hematological malignancies. The isolation of Staphylococcus epidermidis from blood cultures remains a clinical dilemma for physicians and microbiologists. But in many cases this agent is of the clinical significance in immunocompromised patients with hematological malignancies. The role of CMV and EBV in development of bacteremia was demonstrated.

Keywords: infectious complications, blood stream infections, bacteremia, hemoblastosis

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Authors: Rinat Arbel-Goren, Joel Stavans

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Cell-to-cell variations in transcript or protein abundance, called noise, may give rise to phenotypic variability between isogenic cells, enhancing the probability of survival under stress conditions. These variations may be introduced by post-transcriptional regulatory processes such as non-coding, small RNAs stoichiometric degradation of target transcripts in bacteria. We study the iron homeostasis network in Escherichia coli, in which the RyhB small RNA regulates the expression of various targets as a model system. Using fluorescence reporter genes to detect protein levels and single-molecule fluorescence in situ hybridization to monitor transcripts levels in individual cells, allows us to compare noise at both transcript and protein levels. The experimental results and computer simulations show that extrinsic noise buffers through a feed-forward loop configuration the increase in variability introduced at the transcript level by iron deprivation, illuminating the important role that extrinsic noise plays during stress. Surprisingly, extrinsic noise also decouples of fluctuations of two different targets, in spite of RyhB being a common upstream factor degrading both. Thus, phenotypic variability increases under stress conditions by the decoupling of target fluctuations in the same cell rather than by increasing the noise of each. We also present preliminary results on the adaptation of cells to prolonged iron deprivation in order to shed light on the evolutionary role of post-transcriptional downregulation by small RNAs.

Keywords: cell-to-cell variability, Escherichia coli, noise, single-molecule fluorescence in situ hybridization (smFISH), transcript

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Authors: Areej K. Al-Jwaid, Dmitiry Berllio, Andrew Cundy, Irina Savina, Jonathan L. Caplin

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Phenol is a toxic compound that is widely distributed in the environment including the atmosphere, water and soil, due to the release of effluents from the petrochemical and pharmaceutical industries, coking plants and oil refineries. Moreover, a range of daily products, using phenol as a raw material, may find their way into the environment without prior treatment. The toxicity of phenol effects both human and environment health, and various physio-chemical methods to remediate phenol contamination have been used. While these techniques are effective, their complexity and high cost had led to search for alternative strategies to reduce and eliminate high concentrations of phenolic compounds in the environment. Biological treatments are preferable because they are environmentally friendly and cheaper than physico-chemical approaches. Some microorganisms such as Pseudomonas sp., Rhodococus sp., Acinetobacter sp. and Bacillus sp. have shown a high ability to degrade phenolic compounds to provide a sole source of energy. Immobilisation process utilising various materials have been used to protect and enhance the viability of cells, and to provide structural support for the bacterial cells. The aim of this study is to develop a new approach to the bioremediation of phenol based on an immobilisation strategy that can be used in wastewater. In this study, two bacterial species known to be phenol degrading bacteria (Pseudomonas mendocina and Rhodococus koreensis) were purchased from National Collection of Industrial, Food and Marine Bacteria (NCIMB). The two species and mixture of them were immobilised to produce macro porous crosslinked cell cryogels samples by using four types of cross-linker polymer solutions in a cryogelation process. The samples were used in a batch culture to degrade phenol at an initial concentration of 50mg/L at pH 7.5±0.3 and a temperature of 30°C. The four types of polymer solution - i. glutaraldehyde (GA), ii. Polyvinyl alcohol with glutaraldehyde (PVA+GA), iii. Polyvinyl alcohol–aldehyde (PVA-al) and iv. Polyetheleneimine–aldehyde (PEI-al), were used at different concentrations, ranging from 0.5 to 1.5% to crosslink the cells. The results of SEM and rheology analysis indicated that cell-cryogel samples crosslinked with the four cross-linker polymers formed monolithic macro porous cryogels. The samples were evaluated for their ability to degrade phenol. Macro porous cell–cryogels crosslinked with GA and PVA+GA showed an ability to degrade phenol for only one week, while the other samples crosslinked with a combination of PVA-al + PEI-al at two different concentrations have shown higher stability and viability to reuse to degrade phenol at concentration (50 mg/L) for five weeks. The initial results of using crosslinked cell cryogel samples to degrade phenol indicate that is a promising tool for bioremediation strategies especially to eliminate and remove the high concentration of phenol in wastewater.

Keywords: bioremediation, crosslinked cells, immobilisation, phenol degradation

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Authors: Shi-Bo Feng, Sheng-Jie Zhang, Jin Zhou

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The relationship between microbial diversity and algal bloom has received considerable attention for decades. Microbes undoubtedly affect annual bloom events and impact the physiology of both partners, as well as shape ecosystem diversity. However, knowledge about interactions and network correlations among broader-spectrum microbes that lead to the dynamics in a complete bloom cycle are limited. In this study, pyrosequencing and network approaches simultaneously assessed the associate patterns among bacteria, archaea, and microeukaryotes in surface water and sediments in response to a natural dinoflagellate (Alexandrium sp.) bloom. In surface water, among the bacterial community, Gamma-Proteobacteria and Bacteroidetes dominated in the initial bloom stage, while Alpha-Proteobacteria, Cyanobacteria, and Actinobacteria become the most abundant taxa during the post-stage. In the archaea biosphere, it clustered predominantly with Methanogenic members in the early pre-bloom period while the majority of species identified in the later-bloom stage were ammonia-oxidizing archaea and Halobacteriales. In eukaryotes, dinoflagellate (Alexandrium sp.) was dominated in the onset stage, whereas multiply species (such as microzooplankton, diatom, green algae, and rotifera) coexistence in bloom collapse stag. In sediments, the microbial species biomass and richness are much higher than the water body. Only Flavobacteriales and Rhodobacterales showed a slight response to bloom stages. Unlike the bacteria, there are small fluctuations of archaeal and eukaryotic structure in the sediment. The network analyses among the inter-specific associations show that bacteria (Alteromonadaceae, Oceanospirillaceae, Cryomorphaceae, and Piscirickettsiaceae) and some zooplankton (Mediophyceae, Mamiellophyceae, Dictyochophyceae and Trebouxiophyceae) have a stronger impact on the structuring of phytoplankton communities than archaeal effects. The changes in population were also significantly shaped by water temperature and substrate availability (N & P resources). The results suggest that clades are specialized at different time-periods and that the pre-bloom succession was mainly a bottom-up controlled, and late-bloom period was controlled by top-down patterns. Additionally, phytoplankton and prokaryotic communities correlated better with each other, which indicate interactions among microorganisms are critical in controlling plankton dynamics and fates. Our results supplied a wider view (temporal and spatial scales) to understand the microbial ecological responses and their network association during algal blooming. It gives us a potential multidisciplinary explanation for algal-microbe interaction and helps us beyond the traditional view linked to patterns of algal bloom initiation, development, decline, and biogeochemistry.

Keywords: microbial community, harmful algal bloom, ecological process, network

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Authors: Nadia A. Mohamed, Magdy W. Sabaa, Ahmed H. H. El-Ghandour, Marwa M. Abdel-Aziz, Omayma F. Abdel-Gawad

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Eighteen carboxymethyl chitosan (CMCh) schiff bases and their reduced derivatives have been synthesized. They were characterized by spectral analyses (FT-IR and H1-NMR) and scanning electron microscopy observation. Their antibacterial activities against Streptococcus pneumoniae (RCMB 010010), Bacillis subtilis (RCMB 010067), as Gram positive bacteria and Escherichia coli (RCMB 010052) as Gram negative bacteria and the antifungal activity against Aspergillus fumigatus (RCMB 02568), Geotricum candidum (RCMB 05097), and Candida albicans (RCMB 05031) were examined using agar disk diffusion method. The results demonstrate how the antibacterial and the antifungal activity are clearly affected by both the nature and position of the substituent groups in the aryl ring of the prepared derivatives. CMCh-4-nitroBenz Schiff base and its reduced form show higher antimicrobial activity comparing with other para substituted derivatives. CMCh-4-nitroBenz Schiff base: 18.3, 17, and 15.6 mm against Bacillis subtilis, Streptococcus pneumonia, and Escherichia coli respectively and 16.2, 17.3, and 16.4 mm against Aspergillus fumigates, Geotricum candidum, and Candida albicans respectively. CMCh-4-nitroBenz reduced form: 19.5, 18.7, and 16.2 mm against Bacillis subtilis, Streptococcus pneumonia, and Escherichia coli respectively and 17.5, 19.5, and 17.4 mm against Aspergillus fumigates, Geotricum candidum, and Candida albicans respectively. Also CMCh-3-bromoBenz show good results; CMCh-3-bromoBenz schiff base: 19.2, 16.9, and 14.6 mm Bacillis subtilis, Streptococcus pneumonia, and Escherichia coli respectively and 18.4, 17.6, and 15.9 mm against Aspergillus fumigates, Geotricum candidum, and Candida albicans respectively.

Keywords: chitosan, schiff base, minimum inhibition concentration, antimicrobial activity

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Authors: Fezzani Boubaker

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The modified activated sludge model (ASM1 or Mantis) is a generic structured model and a common platform for dynamic simulation of varieties of aerobic processes for optimization and upgrading of existing plants and for new facilities design. In this study, the modified ASM1 included in the GPS-X software was used to simulate the wastewater treatment plant (WWTP) of Beja treating domestic sewage mixed with baker‘s yeast factory effluent. The results of daily measurements and operating records were used to calibrate the model. A sensitivity and an automatic optimization analysis were conducted to determine the most sensitive and optimal parameters. The results indicated that the ASM1 model could simulate with good accuracy: the COD concentration of effluents from the WWTP of Beja for all months of the year 2012. In addition, it prevents the disruption observed at the output of the plant by injecting the baker‘s yeast factory effluent at high concentrations varied between 20 and 80 g/l.

Keywords: ASM1, activated sludge, baker’s yeast effluent, modelling, simulation, GPS-X 5.1 software

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Authors: Aditi Chitharanjan Parmar, Marco Gottardo, Giulia Adele Tuci, Francesco Valentino

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The generation of urban organic waste is a significant environmental problem due to the potential release of leachate and/or methane into the environment. This contributes to climate change, discharging a valuable resource that could be used in various ways. This research addresses this issue by proposing a two-step approach by linking biowaste management to aquaculture industry via single cell proteins (SCP) production. A mixture of food waste and municipal sewage sludge (FW-MSS) was firstly subjected to a mesophilic (37°C) anaerobic fermentation to produce a liquid stream rich in short-chain fatty acids (SCFAs), which are important building blocks for the following microbial biomass growth. In the frame of stable fermentation activity (after 1 week of operation), the average value of SCFAs was 21.3  0.4 g COD/L, with a CODSCFA/CODSOL ratio of 0.77 COD/COD. This indicated the successful strategy to accumulate SCFAs from the biowaste mixture by applying short hydraulic retention time (HRT; 4 days) and medium organic loading rate (OLR; 7 – 12 g VS/L d) in the lab-scale (V = 4 L) continuous stirred tank reactor (CSTR). The SCFA-rich effluent was then utilized as feedstock for the growth of a mixed microbial consortium able to store polyhydroxyalkanoates (PHA), a class of biopolymers completely biodegradable in nature and produced as intracellular carbon/energy source. Given the demonstrated properties of the intracellular PHA as antimicrobial and immunomodulatory effect on various fish species, the PHA-producing culture was intended to be utilized as SCP in aquaculture. The growth of PHA-storing biomass was obtained in a 2-L sequencing batch reactor (SBR), fully aerobic and set at 25°C; to stimulate a certain storage response (PHA production) in the cells, the feast-famine conditions were adopted, consisting in an alternation of cycles during which the biomass was exposed to an initial abundance of substrate (feast phase) followed by a starvation period (famine phase). To avoid the proliferation of other bacteria not able to store PHA, the SBR was maintained at low HRT (2 days). Along the stable growth of the mixed microbial consortium (the growth yield was estimated to be 0.47 COD/COD), the feast-famine strategy enhanced the PHA production capacity, leading to a final PHA content in the biomass equal to 16.5 wt%, which is suitable for the use as SCP. In fact, by incorporating the waste-derived PHA-rich biomass into fish feed at 20 wt%, the final feed could contain a PHA content around 3.0 wt%, within the recommended range (0.2–5.0 wt%) for promoting fish health. Proximate analysis of the PHA-rich biomass revealed a good crude proteins level (around 51 wt%) and the presence of all the essential amino acids (EAA), together accounting for 31% of the SCP total amino acid composition. This suggested that the waste-derived SCP was a source of good quality proteins with a good nutritional value. This approach offers a sustainable solution for urban waste management, potentially establishing a sustainable waste-to-value conversion route by connecting waste management to the growing aquaculture and fish feed production sectors.

Keywords: feed supplement, nutritional value, polyhydroxyalkanoates (PHA), single cell protein (SCP), urban organic waste.

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Authors: Sam Derakhshan Deilami, Iain N. Kings, Lynne E. Macaskie, Brajendra K. Sharma, Anthony V. Bridgwater, Joseph Wood

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This paper reports the application of a bacteria-supported palladium catalyst to the hydrodeoxygenation (HDO) of pyrolysis bio-oil, towards producing an upgraded transport fuel. Biofuels are key to the timely replacement of fossil fuels in order to mitigate the emissions of greenhouse gases and depletion of non-renewable resources. The process is an essential step in the upgrading of bio-oils derived from industrial by-products such as agricultural and forestry wastes, the crude oil from pyrolysis containing a large amount of oxygen that requires to be removed in order to create a fuel resembling fossil-derived hydrocarbons. The bacteria supported catalyst manufacture is a means of utilizing recycled metals and second life bacteria, and the metal can also be easily recovered from the spent catalysts after use. Comparisons are made between bio-Pd, and a conventional activated carbon supported Pd/C catalyst. Bio-oil was produced by fast pyrolysis of beechwood at 500 C at a residence time below 2 seconds, provided by Aston University. 5 wt % BioPd/C was prepared under reducing conditions, exposing cells of E. coli MC4100 to a solution of sodium tetrachloropalladate (Na2PdCl4), followed by rinsing, drying and grinding to form a powder. Pd/C was procured from Sigma-Aldrich. The HDO experiments were carried out in a 100 mL Parr batch autoclave using ~20g bio-crude oil and 0.6 g bio-Pd/C catalyst. Experimental variables investigated for optimization included temperature (160-350C) and reaction times (up to 5 h) at a hydrogen pressure of 100 bar. Most of the experiments resulted in an aqueous phase (~40%) and an organic phase (~50-60%) as well as gas phase (<5%) and coke (<2%). Study of the temperature and time upon the process showed that the degree of deoxygenation increased (from ~20 % up to 60 %) at higher temperatures in the region of 350 C and longer residence times up to 5 h. However minimum viscosity (~0.035 Pa.s) occurred at 250 C and 3 h residence time, indicating that some polymerization of the oil product occurs at the higher temperatures. Bio-Pd showed a similar degree of deoxygenation (~20 %) to Pd/C at lower temperatures of 160 C, but did not rise as steeply with temperature. More coke was formed over bio-Pd/C than Pd/C at temperatures above 250 C, suggesting that bio-Pd/C may be more susceptible to coke formation than Pd/C. Reactions occurring during bio-oil upgrading include catalytic cracking, decarbonylation, decarboxylation, hydrocracking, hydrodeoxygenation and hydrogenation. In conclusion, it was shown that bio-Pd/C displays an acceptable rate of HDO, which increases with residence time and temperature. However some undesirable reactions also occur, leading to a deleterious increase in viscosity at higher temperatures. Comparisons are also drawn with earlier work on the HDO of Chlorella derived bio-oil manufactured from micro-algae via hydrothermal liquefaction. Future work will analyze the kinetics of the reaction and investigate the effect of bi-metallic catalysts.

Keywords: bio-oil, catalyst, palladium, upgrading

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Authors: Zahra Dehghani, Hoda Dehghani, Elham Zarenezhad

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1,2,3-Triazole derivatives are important compounds in medicinal chemistry owing to their wide applications in drug discovery. They can readily associate with biologically targets through the hydrogen bonding and dipole interactions. The 1,2,3-triazole core is a key structural motif in many bioactive compounds, exhibiting a broad spectrum of biological activities, such as antiviral, anticancer, anti-HIV, antibiotic, antibacterial, and antimicrobial. Additionally, they have found significant industrial applications as dyes, agrochemicals, corrosion inhibitors, photo stabilizers, and photographic materials. we disclose the synthesis and characterization of 1-azido-3-(aryl-2-yloxy)propan-2-ol drivatives. The chemistry works well with various ß-azido alcohols involving aryloxy, alkoxy and alkyl residues, and also tolerates a wide spectrum of electron-donating and electron-withdrawing functional groups in both alkyne and azide molecules. Most of ß-azidoalcohols used in these experiments were pre-synthesized by the regioselective ring opening reaction of corresponded epoxides with sodium azide, whereas the majority of terminal alkynes were prepared via SN2-type reaction of propargyl bromide and corresponded nucleophiles. To evaluate the bioactivity of title compounds, the in vitro antifungal activity of all compound was investigated against several pathogenic fungi including Candida albicans, Candida krusei, Aspergillus niger, and Trichophyton rubrum , clotrimazole and fluconazole was used as standard antifungal drugs, also To understand the antibacterial activity of synthesized compounds, they were in vitro screened against E. coli and S. aureus as Gram-negative and Gram-positive bacteria, respectively. The in vitro tests have shown the promising antifungal but marginal antibacterial activity against tested fungi and bacteria.

Keywords: biological activities, antibacterial, antifungal, 1, 2, 3-Triazole

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Authors: Ali Aydin, Mert Sudagidan, Aysen Coban, Alparslan Kadir Devrim

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Pseudomonas spp. (specifically, P. fluorescens and P. fragi) are considered the principal spoilage microorganisms of refrigerated poultry meats. The higher the level psychrophilic spoilage Pseudomonas spp. on carcasses at the end of processing lead to decrease the shelf life of the refrigerated product. The aim of the study was the identification of psychrophilic Pseudomonas spp. having proteolytic and lipolytic activities from poultry meats by 16S rRNA and rpoB gene sequencing, investigation of protease and lipase related genes and determination of proteolytic activity of Pseudomonas spp. In the of isolation procedure, collected chicken meat samples from local markets and slaughterhouses were homogenized and the lysates were incubated on Standard method agar and Skim Milk agar for selection of proteolytic bacteria and tributyrin agar for selection of lipolytic bacteria at +4 °C for 7 days. After detection of proteolytic and lipolytic colonies, the isolates were firstly analyzed by biochemical tests such as Gram staining, catalase and oxidase tests. DNA gene sequencing analysis and comparison with GenBank revealed that 126 strong enzyme Pseudomonas spp. were identified as predominantly P. fluorescens (n=55), P. fragi (n=42), Pseudomonas spp. (n=24), P. cedrina (n=2), P. poae (n=1), P. koreensis (n=1), and P. gessardi (n=1). Additionally, protease related aprX gene was screened in the strains and it was detected in 69/126 strains, whereas, lipase related lipA gene was found in 9 Pseudomonas strains. Protease activity was determined using commercially available protease assay kit and 5 strains showed high protease activity. The results showed that psychrophilic Pseudomonas strains were present in chicken meat samples and they can produce important levels of proteases and lipases for food spoilage to decrease food quality and safety.

Keywords: Pseudomonas, chicken meat, protease, lipase

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Authors: Neha Farid

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Due to the abuse of antimicrobial medications in animal feed, the occurrence of multi-drug resistant (MDR) pathogens in foods is currently a growing public health concern on a global scale. MDR infections have the potential to penetrate the food chain by posing a serious risk to both consumers and animals. Food pathogens are those biological agents that have the tendency to cause pathogenicity in the host body upon ingestion. The major reservoirs of foodborne pathogens include food-producing fauna like cows, pigs, goats, sheep, deer, etc. The intestines of these animals are highly condensed with several different types of food pathogens. Bacterial food pathogens are the main cause of foodborne disease in humans; almost 66% of the reported cases of food illness in a year are caused by the infestation of bacterial food pathogens. When ingested, these pathogens reproduce and survive or form different kinds of toxins inside host cells causing severe infections. The genus Listeria consists of gram-positive, rod-shaped, non-spore-forming bacteria. The disease caused by Listeria monocytogenes is listeriosis or gastroenteritis, which induces fever, vomiting, and severe diarrhea in the affected body. Campylobacter jejuni is a gram-negative, curved-rod-shaped bacteria causing foodborne illness. The major source of Campylobacter jejuni is livestock and poultry; particularly, chicken is highly colonized with Campylobacter jejuni. Serious public health concerns include the widespread growth of bacteria that are resistant to antibiotics and the slowing in the discovery of new classes of medicines. The objective of this study is to provide some potential antibacterial activities with certain broad-range antibiotics and our desired bacteriocins, i.e., Enterococcus faecium from specific strains preventing microbial contamination pathways in order to safeguard the food by lowering food deterioration, contamination, and foodborne illnesses. The food pathogens were isolated from various sources of dairy products and meat samples. The isolates were tested for the presence of Listeria and Campylobacter by gram staining and biochemical testing. They were further sub-cultured on selective media enriched with the growth supplements for Listeria and Campylobacter. All six strains of Listeria and Campylobacter were tested against ten antibiotics. Campylobacter strains showed resistance against all the antibiotics, whereas Listeria was found to be resistant only against Nalidixic Acid and Erythromycin. Further, the strains were tested against the two bacteriocins isolated from Enterococcus faecium. It was found that bacteriocins showed better antimicrobial activity against food pathogens. They can be used as a potential antimicrobial for food preservation. Thus, the study concluded that natural antimicrobials could be used as alternatives to synthetic antimicrobials to overcome the problem of food spoilage and severe food diseases.

Keywords: food pathogens, listeria, campylobacter, antibiotics, bacteriocins

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Authors: Kanika Arora, Madhu Bala

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The small intestine epithelium is highly sensitive and major targets of ionizing radiation. Radiation causes gastrointestinal toxicity either by direct deposition of energy or indirectly (inflammation or bystander effects) generating free radicals and reactive oxygen species. Oxidative stress generated as a result of radiation causes active inflammation within the intestinal mucosa leading to structural and functional impairment of gut epithelial barrier. As a result, there is a loss of tolerance to normal dietary antigens and commensal flora together with exaggerated response to pathogens. Dysbiosis may therefore thought to play a role in radiation enteropathy and can contribute towards radiation induced bowel toxicity. Lactobacilli residing in the gut shares a long conjoined evolutionary history with their hosts and by doing so these organisms have developed an intimate and complex symbiotic relationships. The objective behind this study was to look for the strains with varying resistance to ionizing radiation and to see whether the niche of the bacteria is playing any role in radiation resistance property of bacteria. In this study, we have isolated the Lactobacillus spp. from probiotic preparation and murine gastrointestinal tract, both of which were supposed to be the important source for its isolation. Biochemical characterization did not show a significant difference in the properties, while a significant preference was observed in carbohydrate utilization capacity by the isolates. Effect of ionizing radiations induced by Co60 gamma radiation (10 Gy) on lactobacilli cells was investigated. A cellular survival curve versus absorbed doses was determined. Radiation resistance studies showed that the response of isolates towards cobalt-60 gamma radiation differs from each other and significant decrease in survival was observed in a dose-dependent manner. Thus the present study revealed that the property of radioresistance in Lactobacillus depends upon the source from where they have been isolated.

Keywords: dysbiosis, lactobacillus, mitigation, radiation

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Authors: Fatima Bouazza, Rachida Hassikou, Lamiae Amallah, Jihane Ennadir, Khadija Khedid

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This study evaluated the in vitro resistance and susceptibility of Enterobacteriaceae (Escherichia coli and Klebsiella oxytoca strains) and Staphylococci strains, isolated from sheep’s milk, against antibiotics and essential oils from Thymus satureioides and Mentha pulegium. Antibiotic resistance tests were done using disc diffusion while essential oils were extracted by steam distillation, and yields were calculated relative to plant dry matter. Gas chromatography-mass Spectrometry (GC-MS) was used to analyze each oil's chemical composition. The AMC, CTX, FOX, NA, CN, CIP, and OFX were very effective against the E. coli strains tested. Half of the strains were resistant to AMC, 60% to TIC, and 80% to TE. The K. oxytoca was resistant against AMC, FOX, and TIC (100%). Antibiotic-resistant testing on Staphylococci strains indicated Staphylococcus capitis and Staphylococcus chromogenes as the most sensitive. Staphylococcus aureus, Staphylococcus xylosus, and Staphylococcus cohnii ureal exhibited less resistance to OX, TE, PT, E, and P. The M. pulegium resulted in a higher yield of essential oil of 3.2% oil compared to T. satureioides with only 1.85% yield. Staphylococcus aureus, Staphylococcus xylosus, and Staphylococcus cohnii ureal had lower OX, TE, PT, E, and P resistance. M. pulegium yielded 3.2% essential oil compared to 1.85% for T. satureioides. The monoterpene oxygenated derivatives, monoterpene hydrocarbons, and phenols are found in essential oil extracts. T. satureioides essential oil had high antibacterial activity even at low concentrations (0.2; 0.55 g/mL). The Minimal Bactericidal Concentration (MBC) values indicate that the essential oils from the plants analyzed had bactericidal effects on all strains tested and are similar to the Minimal Inhibitory Concentration (MIC) values. The high antibacterial properties of these medicinal plants, against bacteria isolated from sheep’s milk, provide an opportunity to use these medicinal plants in the breeding sector as additives and preservatives in the dairy industry.

Keywords: antibiotic resistance, medicinal plants, essential oils, enterobacteriaceae, staphylococci, sheep milk

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Authors: Abdullahi Mohammed

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The microbial quality of beef and mutton sold in four major markets of Bauchi metropolis was assessed in order to assist in ascertaining safety. Shops were selected from 'Muda Lawal', 'Yelwa', 'Wunti', and 'Gwallameji' markets. The total bacterial count was used as index of quality. A total of thirty two (32) samples were collected in two successive visits. The samples were packed and labelled in a sterile polythene bags for transportation to the laboratory. Microbial analysis was carried out immediately upon arrival under a septic condition, where aerobic plate was used in determining the microbial load. Result showed that beef and mutton from Gwallameji had the highest bacterial count of 9.065 X 105 cfu/ml and 8.325 X 105 cfu/ml for beef and mutton respectively followed by Wunti market (6.95 X 105 beef and 4.838 X 105 motton) and Muda Lawal (4.86 X 105 cfu/ml beef and 5.998 X 105 cfu/ml mutton). Yelwa had 5.175 X 105 and 5.30 X 105 for beef and mutton respectively. Bacterial species isolated from the samples were Escherichia coli, Salmonella spp, Streptococcus species and Staphylococcus species. However, results obtained from all markets showed that there was no significant differences between beef and mutton in terms of microbial quality.

Keywords: beef, mutton, salmonella, sterile

Procedia PDF Downloads 460

Authors: Monika Trzaskowska, Dorota Zielinska, Anna Lepecka, Katarzyna Neffe-Skocinska, Beata Bilska, Marzena Tomaszewska, Danuta Kolozyn-Krajewska

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Microbiological quality and food safety are important food characteristics. Regulation (EU) No 1169/2011 of the European Parliament and of the Council on the provision of food information to consumers introduces the obligation to provide information on the 'use-by' date or the date of minimum durability (DMD). The second term is the date until which the properly stored or transported foodstuff retains its physical, chemical, microbiological and organoleptic properties. The date should be preceded by 'best before'. It is used for durable products, e.g., pasta. In relation to reducing food losses, the question may be asked whether products with the date of minimum durability currently declared retain quality and safety beyond this. The aim of the study was to assess the sensory quality and microbiological safety of selected cereal products, i.e., pasta and millet after DMD. The scope of the study was to determine the markers of microbiological quality, i.e., the total viable count (TVC), the number of bacteria from the Enterobacteriaceae family and the number of yeast and mold (TYMC) on the last day of DMD and after 1 and 3 months of storage. In addition, the presence of Salmonella and Listeria monocytogenes was examined on the last day of DMD. The sensory quality of products was assessed by quantitative descriptive analysis (QDA), the intensity of 14 differentiators and overall quality were defined and determined. In the tested samples of millet and pasta, no pathogenic bacteria Salmonella and Listeria monocytogenes were found. The value of the distinguishing features of selected quality and microbiological safety indicators on the last DMD day was in the range of about 3-1 log cfu/g. This demonstrates the good microbiological quality of the tested food. Comparing the products, a higher number of microorganisms was found in the samples of millet. After 3 months of storage, TVC decreased in millet, while in pasta, it was found to increase in value. In both products, the number of bacteria from the Enterobacretiaceae family decreased. In contrast, the number of TYMCs increased in samples of millet, and in pasta decreased. The intensity of sensory characteristic in the studied period varied. It remained at a similar level or increased. Millet was found to increase the intensity and flavor of 'cooked porridge' 3 months after DMD. Similarly, in the pasta, the smell and taste of 'cooked pasta' was more intense. To sum up, the researched products on the last day of the minimum durability date were characterized by very good microbiological and sensory quality, which was maintained for 3 months after this date. Based on these results, the date of minimum durability of tested products could be extended. The publication was financed on the basis of an agreement with the National Center for Research and Development No. Gospostrateg 1/385753/1/NCBR/2018 for the implementation and financing of the project under the strategic research and development program 'social and economic development of Poland in the conditions of globalizing markets – GOSPOSTRATEG - acronym PROM'.

Keywords: date of minimum durability, food losses, food quality and safety, millet, pasta

Procedia PDF Downloads 161

Authors: F. Lops, G. Disciglio, A. Carlucci, G. Gatta, L. Frabboni, A. Tarantino, E. Tarantino

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Phelipanche ramosa L. Pomel is a root holoparasitic weed plant of many cultivations, particularly of tomato (Lycopersicum esculentum L.) crop. In Italy, Phelipanche problem is increasing, both in density and in acreage. The biological control of this parasitic weed involves the use of living organisms as numerous fungi and bacteria that can infect the parasitic weed, while it may improve the crop growth. This paper deals with the biocontrol with microorganism, including Arbuscular mycorrhizal (AM) fungi and fungal pathogens as Fusarium oxisporum spp. Colonization of crop roots by AM fungi can provide protection of crops against parasitic weeds because of a reduction in their seed germination and attachment, while F. oxisporum, isolated from diseased broomrape tubercles, proved to be highly virulent on P. ramosa. The experimental trial was carried out in open field at Foggia province (Apulia Region, Southern Italy), during the spring-summer season 2016, in order to evaluate the effect of four biological treatments: AM fungi and Fusarium oxisporum applied in the soil alone or combined together, and Rizosum Max^® product, compared with the untreated control, to reduce the P. ramosa infestation in processing tomato crop. The principal results to be drawn from this study under field condition, in contrast of those reported previously under laboratory and greenhouse conditions, show that both AM fungi and F. oxisporum do not provide the reduction of the number of emerged shoots of P. ramosa. This can arise probably from the low efficacy seedling of the agent pathogens for the control of this parasite in the field. On the contrary, the Rizosum Max^® product, containing AM fungi and some rizophere bacteria combined with several minerals and organic substances, appears to be most effective for the reduction of P. ramosa infestation.

Keywords: Arbuscular mycorrhized fungi, biocontrol methods, Phelipanche ramosa, tomato crop

Procedia PDF Downloads 462

Authors: Michelle Maurer, Antonia Last, Mark S. Gresnigt, Bernhard Hube, Alexander S. Mosig

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The intestinal epithelium forms an essential barrier to prevent translocation of microorganisms, toxins or other potentially harmful molecules into the bloodstream. In particular, dendritic cells of the intestinal epithelium orchestrate an adapted response of immune tolerance to commensals and immune defense against invading pathogens. Systemic inflammation is typically associated with a dysregulation of this adapted immune response and is accompanied by a disruption of the epithelial and endothelial gut barrier which enables dissemination of pathogens within the human body. To understand the pathophysiological mechanisms underlying the inflammation-associated gut barrier breakdown, it is crucial to elucidate the complex interplay of the host and the intestinal microbiome. A microfluidically perfused three-dimensional intestine-on-chip model was established to emulate these processes in the presence of immune cells, commensal bacteria, and facultative pathogens. Multi-organ tissue flow (MOTiF) biochips made from polystyrene were used for microfluidic perfusion of the intestinal tissue model. The biochips are composed of two chambers separated by a microporous membrane. Each chamber is connected to inlet and outlet channels allowing independent perfusion of the individual channels and application of microfluidic shear stress. Human umbilical vein endothelial cells (HUVECs), monocyte-derived macrophages and intestinal epithelial cells (Caco-2) were assembled on the biochip membrane. Following 7 – 14 days of growth in the presence of physiological flow conditions, the epithelium was colonized with the commensal bacterium Lactobacillus rhamnosus, while the endothelium was perfused with peripheral blood mononuclear cells (PBMCs). Additionally, L. rhamnosus was co-cultivated with the opportunistic fungal pathogen Candida albicans. Within one week of perfusion, the epithelial cells formed self-organized and well-polarized villus- and crypt-like structures that resemble essential morphological characteristics of the human intestine. Dendritic cells were differentiated in the epithelial tissue that specifically responds to bacterial lipopolysaccharide (LPS) challenge. LPS is well-tolerated at the luminal epithelial side of the intestinal model without signs of tissue damage or induction of an inflammatory response, even in the presence of circulating PBMC at the endothelial lining. In contrast, LPS stimulation at the endothelial side of the intestinal model triggered the release of pro-inflammatory cytokines such as TNF, IL-1β, IL-6, and IL-8 via activation of macrophages residing in the endothelium. Perfusion of the endothelium with PBMCs led to an enhanced cytokine release. L. rhamnosus colonization of the model was tolerated in the immune competent tissue model and was demonstrated to reduce damage induced by C. albicans infection. A microfluidic intestine-on-chip model was developed to mimic a systemic infection with a dysregulated immune response under physiological conditions. The model facilitates the colonization of commensal bacteria and co-cultivation with facultative pathogenic microorganisms. Both, commensal bacteria alone and facultative pathogens controlled by commensals, are tolerated by the host and contribute to cell signaling. The human intestine-on-chip model represents a promising tool to mimic microphysiological conditions of the human intestine and paves the way for more detailed in vitro studies of host-microbiota interactions under physiologically relevant conditions.

Keywords: host-microbiota interaction, immune tolerance, microfluidics, organ-on-chip

Procedia PDF Downloads 130

Authors: Nelly S. Aggangan, Julieta A. Anarna

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Indigenous tree species are priority planting materials for the National Greening Program of the Department of Environment and Natural Resources. Areas for reforestation are marginal grasslands where plant growth is stunted and seedling survival is low. This experiment was conducted to compare growth rates and seedling survival of seven indigenous reforestation species. Narra (Pterocarpus indicus), salago (Wikstroemia lanceolata), kisubeng (Sapindus saponaria), tuai (Biscofia javanica), batino (Alstonia macrophylla), bani (Pongamina pinnata) and ipil (Intsia bijuga) were inoculated with Mykovam® (mycorrhizal fungi) and Bio-N® (N2-fixing bacteria) during pricking. After five months in the nursery, the treated seedlings were planted in degraded upland acidic red soil in Cavinti, Laguna (Luzon). During outplanting, all mycorrhiza inoculated seedlings had 50-80% mycorrhizal roots while the control ones had 5-10% mycorrhizal roots. Mykovam increased height of narra, salago and kisubeng. Stem diameter was bigger in mycorrhizal salago than the control. After two years in the field, Mykovam®+Bio-N® inoculated narra, salago and bani gave 95% survival while non-mycorrhizal tuai gave the lowest survival (25%). Inoculated seedlings grew faster than the control. Highest height increase was in batino (103%), followed by bani (95%), ipil (59%), narra (58%), tuai (53%) and kisubeng was the lowest (10%). Stem diameter was increased by Mykovam® from 13-39% over the control. Highest stem diameter was obtained from narra (50%), followed by bani (40%), batino (36%), ipil (33%), salago (28%), kisubeng and tuai (12%) had the lowest. In conclusion, Mykovam® inoculated batino, bani, narra, salago and ipil can be selected to restore degraded upland acidic red soil in the Philippines.

Keywords: Azospirillum spp., Bio-N®, Mykovam®, nitrogen fixing bacteria, acidic red soil

Procedia PDF Downloads 309

Authors: Katarína Čurová, Leonard Siegfried, Radka Vargová, Marta Kmeťová, Vladimír Hrabovský

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Introduction: Cytolethal distending toxins (CDTs) represent intracellular acting proteins which interfere with cell cycle of eukaryotic cells. They are produced by Gram-negative bacteria with afinity to mucocutaneous surfaces and could play a role in the pathogenesis of various diseases. CDTs induce DNA damage probably through DNAse activity, which causes cell cycle arrest and leads to further changes (cell distension and death, apoptosis) depending on the cell type. Five subtypes of CDT (I to V) were reported in E. coli. Methods: We examined 252 E. coli strains belonging to four different groups. Of these strains, 57 were isolated from patients with diarrhea, 65 from patients with urinary tract infections (UTI), 65 from patients with sepsis and 65 from patients with other extraintestinal infections (mostly surgical wounds, decubitus ulcers and respiratory tract infections). Identification of these strains was performed by MALDI-TOF analysis and detection of genes encoding CDTs and determination of the phylogenetic group was performed by PCR. Results: In this study, we detected presence of cdt genes in 11 of 252 E. coli strains tested (4,4 %). Four cdt positive E. coli strains were confirmed in group of UTI (6,15 %), three cdt positive E. coli strains in groups of diarrhea (5,3 %) and other extraintestinal infections (4,6 %). The lowest incidence, one cdt positive E. coli strain, was observed in group of sepsis (1,5 %). All cdt positive E. coli strains belonged to phylogenetic group B2. Conclusion: CDT-producing E. coli are isolated in a low percentage from patients with intestinal and extraintestinal infections, including sepsis and our results correspond with these studies. A weak prevalence of cdt genes suggests that CDTs are not major virulence factors but in combination with other virulence factors may increase virulence potential of E. coli. We suppose that all 11 cdt positive E. coli strains represent real pathogens because they belong to the phylogenetic group B2 which is pathogenic lineage for bacteria E. coli.

Keywords: cytolethal distending toxin, E. coli, phylogenetic group, extraintestinal infection, diarrhea

Procedia PDF Downloads 350

Authors: Hamza Hadj Abdallah, Brahim Belabdi

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Respiratory disease is a dominant pathology in cattle. It causes mortality and especially morbidity and irreversible damage. Although the dairy herd is affected, it is essentially the lactating herd and especially young cattle either nursing or fattening that undergo the greatest economic impact. The objective of this study is to establish a microbiological diagnosis of bovine respiratory inffections from lung presented with gross lesions at the slaughter of Batna. A total of 124 samples (pharyngeal and nasal swabs and lung fragments) from 31 seven months old calves, with lung lesions was collected to determine possible correlations between etiologic agents and lesion types. The hépatisation injury (or consolidation) was the major lesion (45.17%) preferentially localized in the right apical lobe. A diverse microbial flora (15 genera and 291 strains was isolated. The bacteria most frequently isolated are the Enterobacteriaceae (49.45%), Staphylococci (25.1%) followed by non Enterobacteriaceae bacilli represented by Pseudomonas (5.83%) and finally, Streptococcus (13.38 %). The pneumotropic bacteria (Pasteurellaaerogenes and Pasteurellapneumotropica) were isolated at a rate of 0.68%. The study of the sensitivity of some germs to antibiotics showed a sensitivity of 100% for ceftazidime. A very high sensitivity was also observed for kanamycin, Ciprofloxacin, Imepinem, Cefepime, Tobramycin and Gentamycin (between 90% and 97%). Strains of E. coli showed a sensitivity of 100% for Imepinem, while only 55.9% of the strains were sensitive to Ampicillin. The isolated Pasteurella exhibited excellent sensitivity (100%) for the antimicrobials used with the exception of Colistin and Ticarcillin-Clavulanic acid association which showed a sensitivity of 50%.This survey has demonstrated the strong spread of atypical pneumonia in cattle population (bulls) at the slaughterhouse of Batna justifying stunting and losses in cattle farms in the region.Thus, it was considered urgent to establish a profile of sensitivity of different germs to antibiotics isolated to limit this increasingly dreadful infection.

Keywords: Pasteurella, enterobacteria, bacteriology, pneumonia

Procedia PDF Downloads 220

Authors: Eda Arat Maden, Ceyhan Altun, Bilal Ozmen, Feridun Basak

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Purpose: The purpose of this study was to compare the antimicrobial effect of toothpastes containing fluoride, xylitol or xylitol-probiotic in vivo, Streptococcus mutans and Lactobacillus in 13-15 years old children. Method: The study consisted of 60 pediatric patients were randomly divided into 3 groups of 20 each. Group 1 received fluoride toothpaste (Colgate Max Fresh), group 2 used xylitol toothpaste (Xyliwhite) and group 3 used xylitol-probiotic toothpaste (PerioBiotic). Subjects were asked to use the allocated dentifrice two times a day, for 6 weeks. We performed tests on the samples of saliva in the beginning of the study and after 6 weeks’ duration following the use of toothpaste. Result and Conclusion: All of the participants of the study stated that they brushed their teeth well twice a day by using the toothpastes given to them for 6 weeks. Majority of the subjects had high counts of salivary mutans streptococci and Lactobacillus at baseline. When the number of cariogenic bacteria (S. mutans and Lactobacillus) at the start of the PerioBiotic Probiotic toothpaste usage are compared with the results measured after 6 weeks, an important decrease is observed in the S. mutans and Lactobacillus bacteria according to the CRT Tests. After the 6-week use of Probiotic toothpaste, the S. mutans (≥105) decreased to 20% from 75% in the group with S. mutans and Lactobacillus (≥105) decreased to 30% from 60% in the group with Lactobacillus. In addition, an important decrease was recorded in the participants with the S. mutans percentage (80% - 45%) and Lactobacillus (70% - 55%) after using the Colgate Max Fresh toothpaste for six weeks. On the other hand, it was determined with the Chi-square that there were not important changes between the Xyliwhite toothpaste group and the other groups with S. mutans (80% - 75%) and Lactobacillus (75% -65%). It was also determined after the comparison of the groups that the decrease in the S. mutans was higher than the group using PerioBiotic Probiotic toothpaste at a significant level, when compared with the Colgate Max Fresh toothpaste and Xyliwhite toothpaste. S. mutans were more sensitive to the antimicrobial activity of the PerioBiotic Probiotic toothpaste and to the Colgate Max Fresh toothpaste when compared with the Lactobacillus. In the light of the data obtained in this in vivo study, the use of probiotics ensure the balance between the bacterial flora in the oral cavity.

Keywords: lactobacillus, probiotic, Streptococcus mutans, toothpaste

Procedia PDF Downloads 260

Authors: Dovilė Bačėninaitė, Karina Džermeikaitė, Justinas Kirvela, Ramūnas Antanaitis

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Bacteria are often present in the mouth of cattle. Some of them can cause abscesses. Starting with severe swelling of the mouth, muscle spasm, or locked jaw, it can lead to inability to open its mouth, move the neck, cause pain while eating. While the calf is unable to eat properly, it becomes more susceptible to infectious diseases, lower weight gain can be observed. Abscesses can be considered as a continuum of oral disease, whereby early stages of the lumpy jaw could proceed from gingivitis to periodontal disease. In the event of tissue damage, bacteria can enter the bloodstream, even cause sepsis. The most common lesions occur when animals eat sharp grass, coarse fodder, sharp, piercing foreign bodies (this is especially common for calves when they are trying to eat inedible objects). A crossbred Holstein calf presented with a history of proliferative outgrowth in the mandibular region. On clinical examination, needle aspiration, mandibular swelling revealed sticky, white curd-like fluid containing. Pus bacteriology revealed gram-negative cocci. They were sensitive to amoxicillin, cephalexin, enrofloxacin, ceftiofur. Blood morphology was in physiological ranges. The calf was treated surgically. The growth was excised, the puss drained and the wound was flushed with potassium permanganate solution (0,01%). A week after clinical surgery examination was performed. The swelling was decreased. Superficial bacterial infections are often associated with poor hygiene, which should be improved before treatment is commenced. Clipping away dirty hair and gently washing affected areas of skin daily with solutions such as povidone-iodine, potassium permanganate is effective. Appropriate antibiotic therapy, based on sensitivity testing, may be used where there is evidence of systemic illness.

Keywords: calf, abscess, lumpy jaw, pus, Streptococcus, Staphylococcus, Actinobacillus, infection

Procedia PDF Downloads 280

Authors: Yan Li, Qingxiang Meng, Bo Zhou, Zhenming Zhou

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The objective of this study was to compare the effects of ensiled mulberry leaves (EML), and sun-dried mulberry fruit pomace (SMFP) on fecal bacterial communities in Simmental crossbred finishing steers fed the following 3 diets: a standard TMR diet, standard diet containing EML and standard diet containing SMFP, and the diets had similar protein and energy levels. Bacterial communities in the fecal content were analyzed using Illumina Miseq sequencing of the V4 region of the 16S rRNA gene amplification. Quantitative real-time PCR was used to detect the selected bacterial species in the feces. Most of the sequences were assigned to phyla Firmicutes (56.67%) and Bacteroidetes(35.90%), followed by Proteobacteria(1.86%), Verrucomicrobia(1.80%) and Tenericutes(1.37%). And the predominant genera included the 5-7N15 (5.91%), CF231 (2.49%), Oscillospira (2.33%), Paludibacter (1.23%) and Akkermansia(1.11%). As for the treatments, no significant differences were observed in Firmicutes (p = 0.28), Bacteroidetes (p = 0.63), Proteobacteria (p = 0.46), Verrucomicrobia (p = 0.17) and Tenericutes (p = 0.75). On the genus level, classified genera with high abundance (more than 0.1%) mainly came from two phyla: Bacteroidetes and Firmicutes. Also no differences were observed in most genera level, 5-7N15 (p = 0.21), CF231 (p = 0.62), Oscillospira (p = 0.9), Paludibacter (p = 0.33) and Akkermansia (p = 0.37), except that rc4-4 were lower in the CON and SMFP groups compared to the EML animals (p = 0.02). Additionally, there were no differences in richness estimate and diversity indices (p > 0.16), and treatments had no significant effect on most selected bacterial species in the fecal (p > 0.06), except that Ruminococcus albus were higher in the EML group (p < 0.01) and Streptococcus bovis were lower in the CON group (p < 0.01). In conclusion, diets supplemented with EML and SMFP have little influence on fecal bacterial community composition in finishing steers.

Keywords: fecal bacteria community composition, sequencing, ensiled mulberry leaves (EML), sun-dried mulberry fruit pomace (SMFP)

Procedia PDF Downloads 322

Authors: Antonio Marco Miotti, Antonella Ruffatto, Giampaola Basso, Antonio Madia, Giulia Zavatta, Emanuela Salvatico, Emanuela Zilli

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A National Action Plan to fight antimicrobial resistance was launched in Italy in 2017. In order to reduce inappropriate exposure to antibiotics and infections from multi-drug resistant bacteria, it is essential to set up a structured system of surveillance and monitoring of the implementation of National Action Plan standards, including antimicrobial consumption, with a special focus on quinolones, third generation cephalosporins and carbapenems. A quantitative estimate of antibiotic consumption (defined daily dose - DDD - consumption per 100 days of hospitalization) has been provided by the Pharmaceutical Service to the Hospital of Cittadella, ULSS 6 Euganea – Health Trust (District of Padua) for the years 2019 (before the pandemic), 2020 and 2021 for all classes of antibiotics. Multidisciplinary meetings have been organized monthly by the local Antimicrobial Stewardship Group. Between 2019 and 2021, an increase in the consumption of carbapenems in the Intensive Care Unit (from 12.2 to 18.2 DDD, + 49.2%) and a decrease in Medical wards (from 5.3 to 2.6 DDD, - 50.9%) was reported; a decrease in the consumption of quinolones in Intensive Care Unit (from 17.2 to 10.8 DDD, - 37.2%), Medical wards (from 10.5 to 6.6 DDD, - 37.1%) and Surgical wards (from 10.2 to 9.3 DDD, - 8.8%) was highlighted; an increase in the consumption of third generation cephalosporins in Medical wards (from 18.1 to 22.6 DDD, + 24,1%) was reported. Finally, after an increase in the consumption of macrolides between 2020 and 2019, in 2021, a decrease was reported in the Intensive Care Unit (DDD: 8.0 in 2019, 18.0 in 2020, 6.4 in 2021) and Medical wards (DDD: 9.0 in 2019, 13.7 in 2020, 10.9 in 2021). Constant monitoring of antimicrobial consumption and timely identifying of warning situations that may need a specific intervention are the cornerstone of Antimicrobial Stewardship programs, together with analysing data on bacterial resistance rates and infections from multi-drug resistant bacteria.

Keywords: carbapenems, quinolones, antimicrobial, stewardship

Procedia PDF Downloads 157

Authors: N. R. Prasannakumar, M. N. Maruthi

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The whitefly, Bemisia tabaci (Gennadius) (Hemiptera; Aleyrodidae) is a highly polyphagous pest reported to infest over 600 plant hosts globally. About 42 genetic groups/cryptic species of B. tabaci exist in the world on different hosts. The species have variable behaviour with respect to feeding, development and transmission of viral diseases. Feeding on diverse host plants affect both whitefly development and the population of the endosymbionts harboured by the insects. Due to changes in the level of endosymbionts, the virus transmission efficiency by the vector also gets affected. We investigated these interactions on five host plants – egg plant, tomato, beans, okra and cotton - using a single whitefly species Asia 1 infected with three different bacteria Portiera, Wolbachia and Arsenophonus. The Asia 1 transmits the Tomato leaf curl Bangalore virus (ToLCBV) effectively and thus was used in the interaction studies. We found a significant impact of hosts on whitefly growth and development; eggplant was most favourable host, while okra and tomato were least favourable. Among the endosymbiotic bacteria, the titre of Wolbachia was significantly affected by feeding of B. tabaci on different host plants whereas Arsenophonus and Portiera were unaffected. When whitefly fed on ToLCBV-infected tomato plants, the Arsenophonus population was significantly increased, indicating its previously confirmed role in ToLCBV transmission. Further, screening of total proteins of B. tabaci Asia 1 genetic group interacting with ToLCBV coat protein was carried out using Y2H system. Some of the proteins found to be interacting with ToLCBV CP were HSPs 70kDa, GroEL, nucleoproteins, vitellogenins, apolipophorins, lachesins, enolase. The reported protein thus would be the potential targets for novel whitefly control strategies such as RNAi or novel insecticide target sites for sustainable whitefly management after confirmation of genuine proteins.

Keywords: cDNA, whitefly, ToLCBV, endosymbionts, Y2H

Procedia PDF Downloads 115

Authors: Yuriko Takayama, Norihiro Kato

Abstract:

Quorum sensing (QS) is a cell-to-cell communication system in bacteria to regulate expression of target genes. In gram-negative bacteria, activation on QS is controlled by a concentration increase of N-acylhomoserine lactone (AHL), which can diffuse in and out of the cell. Effective control of QS is expected to avoid virulence factor production in infectious pathogens, biofilm formation, and antibiotic production because various cell functions in gram-negative bacteria are controlled by AHL-mediated QS. In this research, we applied cyclodextrins (CDs) as artificial hosts for the AHL signal to reduce the AHL concentration in the culture broth below its threshold for QS activation. The AHL-receptor complex induced under the high AHL concentration activates transcription of the QS-target gene. Accordingly, artificial reduction of the AHL concentration is one of the effective strategies to inhibit the QS. A hydrophobic cavity of the CD can interact with the acyl-chain of the AHL due to hydrophobic interaction in aqueous media. We studied N-hexanoylhomoserine lactone (C6HSL)-mediated QS in Serratia marcescens; accumulation of C6HSL is responsible for regulation of the expression of pig cluster. Inhibitory effects of added CDs on QS were demonstrated by determination of prodigiosin amount inside cells after reaching stationary phase, because production of prodigiosin depends on the C6HSL-mediated QS. By adding approximately 6 wt% hydroxypropyl-β-CD (HP-β-CD) in Luria-Bertani (LB) medium prior to inoculation of S. maecescens AS-1, the intracellularly accumulated prodigiosin was drastically reduced to 7-10%, which was determined after the extraction of prodigiosin in acidified ethanol. The AHL retention ability of HP-β-CD was also demonstrated by Chromobacterium violacuem CV026 bioassay. The CV026 strain is an AHL-synthase defective mutant that activates QS solely by adding AHLs from outside of cells. A purple pigment violacein is induced by activation of the AHL-mediated QS. We demonstrated that the violacein production was effectively suppressed when the C6HSL standard solution was spotted on a LB agar plate dispersing CV026 cells and HP-β-CD. Physico-chemical analysis was performed to study the affinity between the immobilized CD and added C6HSL using a quartz crystal microbalance (QCM) sensor. The COOH-terminated self-assembled monolayer was prepared on a gold electrode of 27-MHz AT-cut quartz crystal. Mono(6-deoxy-6-N, N-diethylamino)-β-CD was immobilized on the electrode using water-soluble carbodiimide. The C6HSL interaction with the β-CD cavity was studied by injecting the C6HSL solution to a cup-type sensor cell filled with buffer solution. A decrement of resonant frequency (ΔFs) clearly showed the effective C6HSL complexation with immobilized β-CD and its stability constant for MBP-SpnR-C6HSL complex was on the order of 102 M-1. The CD has high potential for engineered control of QS because it is safe for human use.

Keywords: acylhomoserine lactone, cyclodextrin, intracellular signaling, quorum sensing

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