Search results for: MDR pathogen

Authors: A. Y. Benabdellah, W. Lakhdari, A. Dahliz, Y. Bouchikh, A. Soud, R. M'lik, H. Hammi

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The direct comparison tests on the culture medium, between Trichoderma sp. and Fusarium oxysporum f. sp. radicis-lycopersici revealed that the latest one could inhibit the growth of F. oxysporum mycelial over than 40% compared to the control and that after four days of incubation at 26° C. Moreover, beyond this period and at the end of six days, Trichoderma sp. invading the colonies of F. oxysporum on what it sporule, thus revealing its power is highly myco-parasitic. Almost similar results were obtained against Alternaria solani is also a pathogen which is not causing a lot of damage, but we found it more sensitive to Trichoderma sp. with a percentage of inhibition more than 50%. So due to the in vitro test of Trichoderma sp. against these aggressive pathogens by direct contact has been found that can inhibit their mycelial growth with high speed and a high inhibition rate.

Keywords: Trichoderma sp., Fusarium oxysporum f. sp. radicis-lycopersici, Alternaria solani, biological control, antagonist

Procedia PDF Downloads 344

Authors: W. S. Thulasitha, N. Umasuthan, G. I. Godahewa, Jehee Lee

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In fish, innate immune defense is the first immune response against microbial pathogens which consists of several antimicrobial components. Galectins are one of the carbohydrate binding lectins that have the ability to identify pathogen by recognition of pathogen associated molecular patterns. Galectins play a vital role in the regulation of innate and adaptive immune responses. Rock bream Oplegnathus fasciatus is one of the most important cultured species in Korea and Japan. Considering the losses due to microbial pathogens, present study was carried out to understand the molecular and functional characteristics of a galectin in normal and pathogenic conditions, which could help to establish an understanding about immunological components of rock bream. Complete cDNA of rock bream galectin like protein B (rbGal like B) was identified from the cDNA library, and the in silico analysis was carried out using bioinformatic tools. Genomic structure was derived from the BAC library by sequencing a specific clone and using Spidey. Full length of rbGal like B (contig14775) cDNA containing 517 nucleotides was identified from the cDNA library which comprised of 435 bp in the open reading frame encoding a deduced protein composed of 145 amino acids. The molecular mass of putative protein was predicted as 16.14 kDa with an isoelectric point of 8.55. A characteristic conserved galactose binding domain was located from 12 to 145 amino acids. Genomic structure of rbGal like B consisted of 4 exons and 3 introns. Moreover, pairwise alignment showed that rock bream rbGal like B shares highest similarity (95.9 %) and identity (91 %) with Takifugu rubripes galectin related protein B like and lowest similarity (55.5 %) and identity (32.4 %) with Homo sapiens. Multiple sequence alignment demonstrated that the galectin related protein B was conserved among vertebrates. A phylogenetic analysis revealed that rbGal like B protein clustered together with other fish homologs in fish clade. It showed closer evolutionary link with Takifugu rubripes. Tissue distribution and expression patterns of rbGal like B upon immune challenges were performed using qRT-PCR assays. Among all tested tissues, level of rbGal like B expression was significantly high in gill tissue followed by kidney, intestine, heart and spleen. Upon immune challenges, it showed an up-regulated pattern of expression with Edwardsiella tarda, rock bream irido virus and poly I:C up to 6 h post injection and up to 24 h with LPS. However, In the presence of Streptococcus iniae rbGal like B showed an up and down pattern of expression with the peak at 6 - 12 h. Results from the present study revealed the phylogenetic position and role of rbGal like B in response to microbial infection in rock bream.

Keywords: galectin like protein B, immune response, Oplegnathus fasciatus, molecular characterization

Procedia PDF Downloads 325

Authors: Mehdi Moradi Sarmeidani, Peyman Keyhani, Hasan Momtaz

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Chlamydophila psittaci is a avian pathogen that may cause respiratory disorders in humans. Conjunctival and cloacal swabs from 54 captive psittacine birds presented at veterinary clinics were collected to determine the prevalence of C. psittaci in domestic birds in Isfahan. Samples were collected during 2014 from a total of 10 different species of parrots, with African gray(33), Cockatiel lutino(3), Cockatiel gray(2), Cockatiel cinnamon(1), Pearl cockatiel(6), Timneh African grey(1), Ringneck parakeet(2), Melopsittacus undulatus(1), Alexander parakeet(2), Green Parakeet(3) being the most representative species sampled. C. psittaci was detected in 27 (50%) birds using molecular detection (PCR) method. The detection of this bacterium in captive psittacine birds shows that there is a potential risk for human whom has a direct contact and there is a possibility of infecting other birds.

Keywords: chlamydophila psittaci, psittacine birds, PCR, Isfahan

Procedia PDF Downloads 340

Authors: Bouchenak Fatima, Lmegharbi Abdelbaki, Houssem Degaichia, Benrebiha Fatima

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The essential oil composition of the leaf of Artemisia absinthium from region of Cherchell (The south of Algeria) was investigated by GC, GC-MS. 27 constituents were identified correspond to 84, 63% of the total oil. The major components are Thujone (60, 82%), Chamazulènel (16, 62%), ρ-cymène (4, 29%) and 2-carène (4.25%). The antimicrobial activity of oil was tested in vitro by two methods (agar diffusion and microdilution) on three plant pathogenic fungi. This oil has been tested for antimicrobial activity against three pathogenic fungi (Botrytis cinerea, Fusarium culmorum and Helminthosporium Sp.).The study of activity was evaluated by two methods: Method of diffusion in gelose and the minimum inhibitory concentration MIC. This oil exhibited an interesting antimicrobial activity. A preliminary study showed that this oil presented high toxicity against this fungus. These results, although preliminary show a good antifungal activity, to limit and inhibit stop the development of those pathogen agent.

Keywords: artemisia absinthian, extraction process, chemical study, antifungal activity

Procedia PDF Downloads 441

Authors: Nqobile Muleya, Winston Garira, Godwin Mchau

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Citrus Black Spot (CBS) is a fungal disease that is responsible for huge economical loss and poses a threat to the citrus industry worldwide. We construct a mathematical model framework for citrus black spot between fruits to characterise the dynamics of the disease development, paying attention to the pathogen life cycle. We have made an observation from the model analysis that the initial inoculum from ascomata is very important for disease development and thereafter it is no longer important due to conidia which is responsible for secondary infection. Most importantly, the model indicated that ascospores and conidia are very important parameters in developing citrus black spot within a short distance. The basic reproductive number and its importance in relation to citrus black spot persistence are outlined. A numerical simulation of the model was done to explain the theoretical findings.

Keywords: epidemiological modelling, Guidnardia citricarpa, life cycle stage, fungal, disease development

Procedia PDF Downloads 338

Authors: I. Tulay Cagatay

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Blue-green microalgae cyanobacteria, which are important photosynthetic organisms of aquatic ecosystems, are the primary sources of many bioactive compounds such as proteins, carbohydrates, lipids, vitamins and enzymes that can be used as antimicrobial and antiviral agents. Some of these organisms are nowadays used directly in the food, cosmetic and pharmaceutical industry, or in aquaculture and biotechnological approaches like biofuel or drug therapy. Finding the effective, environmental friendly chemotropic and antimicrobial agents to control fish pathogens are crucial in a country like Turkey which has a production capacity of about 240 thousand tons of cultured fish and has 2377 production farms and which is the second biggest producer in Europe. In our study, we tested the antimicrobial activity of cyanobacterium spp. against some fish pathogens Aeromonas hydrophila and Yersinia ruckeri that are important pathogens for rainbow trout farms. Agar disk diffusion test method was used for studying antimicrobial activity on pathogens. Both tested microorganisms have shown antimicrobial activity positively as the inhibition zones were 0.45 mm and 0.40 mm respectively.

Keywords: fish pathogen, cyanobacteria, antimicrobial activity, trout

Procedia PDF Downloads 133

Authors: Angelica Alvarez-Lee, Sergio Martinez-Diaz, Jose Luis Garcia-Corona, Humberto Lanz-Mendoza

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World aquaculture is always looking for improvements to achieve productions with high yields avoiding the infection by pathogenic agents. The best way to achieve this is to know the biological model to create alternative treatments that could be applied in the hatcheries, which results in greater economic gains and improvements in human public health. In the last decade, immunomodulation in shrimp culture with probiotics, organic acids and different carbon sources has gained great interest, mainly in larval and juvenile stages. Immune priming is associated with a strong protective effect against a later pathogen challenge. This work provides another perspective about immunostimulation from spawning until hatching. The stimulation happens during development embryos and generates resistance to infection by pathogenic bacteria. Massive spawnings of white shrimp L. vannamei were obtained and placed in experimental units with 700 mL of sterile seawater at 30 °C, salinity of 28 ppm and continuous aeration at a density of 8 embryos.mL⁻¹. The immunostimulating effect of three death strains of non-pathogenic bacterial (Escherichia coli, Staphylococcus aureus and Bacillus subtilis) and a pathogenic strain for white shrimp (Vibrio parahaemolyticus) was evaluated. The strains killed by heat were adjusted to O.D. 0.5, at A 600 nm, and directly added to the seawater of each unit at a ratio of 1/100 (v/v). A control group of embryos without inoculum of dead bacteria was kept under the same physicochemical conditions as the rest of the treatments throughout the experiment and used as reference. The duration of the stimulus was 12 hours, then, the larvae that hatched were collected, counted and transferred to a new experimental unit (same physicochemical conditions but at a salinity of 28 ppm) to carry out a challenge of infection against the pathogen V. parahaemolyticus, adding directly to seawater an amount 1/100 (v/v) of the live strain adjusted to an OD 0.5; at A 600 nm. Subsequently, 24 hrs after infection, nauplii survival was evaluated. The results of this work shows that, after 24 hrs, the hatching rates of immunostimulated shrimp embryos with the dead strains of B. subtillis and V. parahaemolyticus are significantly higher compared to the rest of the treatments and the control. Furthermore, survival of L. vanammei after a challenge of infection of 24 hrs against the live strain of V. parahaemolyticus is greater (P < 0.05) in the larvae immunostimulated during the embryonic development with the dead strains B. subtillis and V. parahaemolyticus, followed by those that were treated with E. coli. In summary superficial antigens can stimulate the development cells to promote hatching and can have normal development in agreeing with the optical observations, plus exist a differential response effect between each treatment post-infection. This research provides evidence of the immunostimulant effect of death pathogenic and non-pathogenic bacterial strains in the rate of hatching and oversight of shrimp L. vannamei during embryonic and larval development. This research continues evaluating the effect of these death strains on the expression of genes related to the defense priming in larvae of L. vannamei that come from massive spawning in hatcheries before and after the infection challenge against V. parahaemolyticus.

Keywords: immunostimulation, L. vannamei, hatching, survival

Procedia PDF Downloads 115

Authors: Nahid H. Hajrah, Jamal S. M. Sabir, Neil Hall

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The jasmonic pathway is ubiquitous in plants and is crucial to plant development. It Is involved in fertility, ripening, and sex determination as well as in response to environmental stresses such as herbivory, pathogen drought or temperature shock. Essentially the jasmonic pathway acts to shut down growth in order to induce defence pathways. These pathways include the production of secondary metabolites which have evolved to defend against herbivores and pathogens but are of increasing interest due to their roll in medicine and biotechnology. Here we describe the transcriptional response of Rhazia stricta (a poisonous shrub widely used in traditional medicine) to jasmonic acid, in order to better characterize the genes involved in secondary metabolite production and its response to stress. We observe coordinated upregulation of flavonoid biosynthesis pathway leading to flavonols, flavones and anthocyanins but no similar coordination of the monoterpene indole alkaloid pathway.

Keywords: medicinal plants, Rhazia stricta, jasmonic acid, transcriptional analysis

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Authors: S. F. Afzali, W. L. Wong

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The epizootic ulcerative syndrome (EUS) causes by the oomycete fungus, Aphanomyces invadans; known to be one of the infectious fish diseases for farmed and wild fishes in fresh and brackish-water from the Asia-pacific region, America and Africa. Although, EUS had been documented by the Office International des Epizooties (OIE) since 1995, hitherto, there is neither standard chemical agents that can be used for successful treatment of this destructive infection in the time of outbreak; nor available vaccine for prevention. Plant-based remedies in controlling fish diseases are gaining much attention recently as an alternative to chemical treatments, which possess negative effects to the environment and human. In present study, Sonneratia alba, a mangrove plant belongs to the Sonneratiaceae family, was screened in vitro and in vivo for its antifungal activity against A. invadans mycelium growth and its effects on fish innate immune system and disease resistant. The in vitro tests was performed using the disc diffusion methods with measurements of minimum inhibitory concentration (MIC) and inhibition zone. For in vivo study, the S. alba extract supplemented diets were administrated at 0.0, 1.0%, 3.0%, and 5.0% on healthy goldfish, Carassius auratus, which challenged with A. invadans zoospores (100 spores/ml). To compare the significant differences in the hematological and immunological parameters obtained from the experiments, the data were analysed using the SPSS. The methanol extract of S. alba effectively inhibited the mycelial growth of A. invadans at a minimum concentration of 1000 ppm for agar and filter paper diffusion experiments. In the agar diffusion test, 500 ppm of the extract inhibited the fungus mycelial growth up to 96 hours after exposure. The mycelial growth from the edge of the pre-inoculated A. invadans agar discs treated with S. alba extracts at concentrations of 100, 500 and 1000 ppm were 15, 8 and 0 mm respectively. The results of the filter paper disc test showed that the S. alba extract at its minimal inhibitory concentration (1000 ppm) has similar qualitative inhibitory effect as malachite green at 1 ppm and formalin at 250 ppm. According to the in vivo tests findings, in the infected fish fed with 3.0% and 5.0% supplementation diet, the numbers of white blood cell and myeloperoxidase activity significantly increased after the second week of treatment. Whilst the numbers of red blood cell significantly decreased in the infected fish fed with 0.0 and 1.0% supplementation diet. After the third week of feeding, significant increases in the total protein, albumin level, lysozyme activity were recorded in the infected fish fed with 3.0% and 5.0% supplementation diet. Also, the enriched diets increased the survival rate as compared to the untreated group that suffered from 90% mortality. The present study indicated that S. alba extract may inhibit the mycelial growth of A. invadans effectively, suggesting an alternative to other chemotherapeutic agents, which brought much environmental and health concerns to the public, for EUS treatment.

Keywords: fungal pathogen, goldfish, organic extract, treatment

Procedia PDF Downloads 255

Authors: Bo Ram Choi, Ji Su Kim, Juyeon Cho, Hyukjin Lee

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Food contaminated by bacteria (E.coli), causes food poisoning, which occurs to many patients worldwide annually. We have introduced an application of rolling circle amplification (RCA) as a versatile biosensor and developed a diagnostic platform composed of capillary tube and microbeads for rapid and easy detection of Escherichia coli (E. coli). When specific mRNA of E.coli is extracted from cell lysis, rolling circle amplification (RCA) of DNA template can be achieved and can be visualized by beads aggregation in capillary tube. In contrast, if there is no bacterial pathogen in sample, no beads aggregation can be seen. This assay is possible to detect visually target gene without specific equipment. It is likely to the development of a genetic kit for point of care testing (POCT) that can detect target gene using microbeads.

Keywords: rolling circle amplification (RCA), Escherichia coli (E. coli), point of care testing (POCT), beads aggregation, capillary tube

Procedia PDF Downloads 335

Authors: Kaouther Jaouadi, Jihene Bettaieb, Amira Bennour, Ghassen Kharroubi, Sadok Salem, Afif Ben Salah

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In Tunisia, chronic cutaneous leishmaniasis due to Leishmania (L) tropica is an important health problem. Its spreading has not been fully elucidated. Information on sandfly vectors, as well as their associated Leishmania species, is of paramount importance since vector dispersion is one of the major factors responsible for pathogen dissemination. In total, 650 sandflies were captured between June and August 2015 using sticky paper traps in the governorate of Sidi Bouzid, a classical focus of L. major in the Central-West of Tunisia. Polymerase chain reaction-restriction fragment length polymorphism analysis of the internal transcribed spacer 1 and sequencing were used for Leishmania detection and identification. Ninety-seven unfed females were tested for the presence of Leishmania parasite DNA. Six Phlebotomus sergenti were found positive for L. tropica. This finding enhances the understanding of the cycle extension of L. tropica outside its original focus of Tataouine in the South-East of the country.

Keywords: cutaneous leishmaniasis, Leishmania tropica, sandflies, Tunisia

Procedia PDF Downloads 124

Authors: Hanan Moawad, Naglaa M. Abd EL-Rahman

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Erwinia carotovora var. carotovora is the main cause of soft rot in potatoes. Hyphaene thebaica was studied for biocontrol of E. carotovora which inhibited growth of E. carotovora on solid medium, a comparative study of classical and ultrasound-assisted extractions of Hyphaene thebaica fruit. The use of ultrasound decreased significant the total time of treatment and increase the total amount of crude extract. The crude extract was subjected to determine the in vitro, by a bioassay technique revealed that the treatment of paper disks with ultrasound extraction of Hyphaene thebaica reduced the growth of pathogen and produced inhibition zones up to 38mm in diameter. The antioxidant activity of ultrasound-ethanolic extract of Doum fruits (Hyphaene thebaica) was determined. Data obtained showed that the extract contains the secondary metabolites such as Tannins, Saponin, Flavonoids, Phenols, Steroids, Terpenoids, Glycosides and Alkaloids.

Keywords: ultrasound, classical extract, biological control, Erwinia carotovora, Hyphaene thebaica

Procedia PDF Downloads 495

Authors: Hattie Hope Makumbe, Bhekisisa Dlamini, Frederick Tabit

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Listeria monocytogenes is one of the most important foodborne pathogens associated with ready-to-eat (RTE) food. This study investigated the incidence of Listeria monocytogenes in 80 RTE food sold in the formal (dairy and processed meat) and informal markets (vegetable salads, beef stew, and rice) of Johannesburg, South Africa. High Enterobacteriaceae, S. aureus, and E. coli counts were obtained, which ranged from 1.9-7.5 log CFU/g. Listeria monocytogenes microbial counts in the food samples ranged from 3.5-6.0 log colony forming unit per gram except in cooked rice. The Listeria monocytogenes isolates were identified using biochemical tests and confirmed with the Biolog identification system and PCR analyses. The percentage incidence for Listeria monocytogenes in ready to eat food was 12.5%. When Minimum Inhibitory Concentrations were under consideration, all disinfectants were effective against Listeria monocytogenes strains. For antimicrobial work, rates of resistance amongst the antibiotics ranged from 17-100%. Therefore, more effective preventive control strategies for Listeria monocytogenes are needed to reduce the prevalence of the pathogen in RTE food that is sold in Johannesburg.

Keywords: Listeria monocytogenes, Listeria species, ready to eat food, sanitiser efficacy

Procedia PDF Downloads 128

Authors: Susmita Sharma, Pankaj Pathak

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Biosolids are by-products of municipal and industrial wastewater treatment process. The generation of the biosolids is increasing at an alarming rate due to the implementation of strict environmental legislation to improve the quality of discharges from wastewater treatment plant. As such, proper management and safe disposal of sewage sludge have become a worldwide topic of research. Biosolids, rich in organic matter and essential micro and macronutrients; can be used as a soil conditioner, to cut fertilizer costs and create favorable conditions for vegetation. However, it also contains pathogens and heavy metals which are undesirable as they are harmful to both humans and the environment. Therefore, for safe utilization of biosolids for land application purposes, categorization of the contaminant and pathogen is mandatory. In this context, biosolids collected from a wastewater treatment plant in Maharashtra are utilized to determine its physical, chemical and microbiological attributes. This study would ascertain, if the use of these materials from the specific site, are suitable for agriculture. Further, efforts have also been made to present the internationally acceptable legal standards and guidelines for biosolids management or application.

Keywords: biosolids, sewage, heavy metal, sustainable agriculture

Procedia PDF Downloads 299

Authors: Goksen Arik, Mihriban Korukluoglu

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Lactic acid bacteria (LAB) has been used commonly in the food industry. They can be used as natural preservatives because acidifying carried out in the medium can protect the last product against microbial spoilage. Besides, other metabolites produced by LAB during fermentation period have also an antimicrobial effect on pathogen and spoilage microorganisms in the food industry. LAB are responsible for the desirable and distinctive aroma and flavour which are observed in fermented food products such as pickle, kefir, yogurt, and cheese. Various LAB strains are able to produce B-group vitamins such as folate (B11), riboflavin (B2) and cobalamin (B12). Especially wild-type strains of LAB can produce B-group vitamins in high concentrations. These cultures may be used in food industry as a starter culture and also the microbial strains can be used in encapsulation technology for new and functional food product development. This review is based on the current applications of B-group vitamin producing LAB. Furthermore, the new technologies and innovative researches about B vitamin production in LAB have been demonstrated and discussed for determining their usage availability in various area in the food industry.

Keywords: B vitamin, food industry, lactic acid bacteria, starter culture, technology

Procedia PDF Downloads 347

Authors: Massimiliano Biagini, Marco Spinsanti, Gabriella De Angelis, Sara Tomei, Ilaria Ferlenghi, Maria Scarselli, Alessia Biolchi, Alessandro Muzzi, Brunella Brunelli, Silvana Savino, Marzia M. Giuliani, Isabel Delany, Paolo Costantino, Rino Rappuoli, Vega Masignani, Nathalie Norais

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The gram-negative bacterium Neisseria meningitidis serogroup B (MenB) is an exclusively human pathogen representing the major cause of meningitides and severe sepsis in infants and children but also in young adults. This pathogen is usually present in the 30% of healthy population that act as a reservoir, spreading it through saliva and respiratory fluids during coughing, sneezing, kissing. Among surface-exposed protein components of this diplococcus, factor H binding protein is a lipoprotein proved to be a protective antigen used as a component of the recently licensed Bexsero vaccine. fHbp is a highly variable meningococcal protein: to reflect its remarkable sequence variability, it has been classified in three variants (or two subfamilies), and with poor cross-protection among the different variants. Furthermore, the level of fHbp expression varies significantly among strains, and this has also been considered an important factor for predicting MenB strain susceptibility to anti-fHbp antisera. Different methods have been used to assess fHbp expression on meningococcal strains, however, all these methods use anti-fHbp antibodies, and for this reason, the results are affected by the different affinity that antibodies can have to different antigenic variants. To overcome the limitations of an antibody-based quantification, we developed a quantitative Mass Spectrometry (MS) approach. Selected Reaction Monitoring (SRM) recently emerged as a powerful MS tool for detecting and quantifying proteins in complex mixtures. SRM is based on the targeted detection of ProteoTypicPeptides (PTPs), which are unique signatures of a protein that can be easily detected and quantified by MS. This approach, proven to be highly sensitive, quantitatively accurate and highly reproducible, was used to quantify the absolute amount of fHbp antigen in total extracts derived from 105 clinical isolates, evenly distributed among the three main variant groups and selected to be representative of the fHbp circulating subvariants around the world. We extended the study at the genetic level investigating the correlation between the differential level of expression and polymorphisms present within the genes and their promoter sequences. The implications of fHbp expression on the susceptibility of the strain to killing by anti-fHbp antisera are also presented. To date this is the first comprehensive fHbp expression profiling in a large panel of Neisseria meningitidis clinical isolates driven by an antibody-independent MS-based methodology, opening the door to new applications in vaccine coverage prediction and reinforcing the molecular understanding of released vaccines.

Keywords: quantitative mass spectrometry, Neisseria meningitidis, vaccines, bexsero, molecular epidemiology

Procedia PDF Downloads 278

Authors: Bahaa Eldin Kornah

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The organism profile for peri-prosthetic joint infection caused by hematogenous seeding or direct inoculations is changing. The organisms that cause prosthetic joint infections range from normal skin colonizers to highly virulent pathogens. The pathogens continue to evolve. While Staphylococcus aureus continues to be the leading organism, gram-negative bacilli account for approximately 7% of cases and that incidence is increasing. Methicillin-resistant S. aureus(MRSA) accounts for approximately 10% of all infections occurring in the community setting and 20% of those in the health care setting. The list of organisms causing PJI has expanded in recent years. It is important to have an understanding of which organisms may be causing a periprosthetic joint infection based on where the patient contracted it and their recent medical history. Also, recent technology has expanded rapidly and new methods to detect the pathogen and why we failed in detecting it. There are a number of explanations for the latter finding, perhaps the most important reason being the liberal use of antibiotics that interferes with the isolation of the infective organism.

Keywords: infection, periprosthetic, hip, organism profile, joint infection, joint infection

Procedia PDF Downloads 55

Authors: Mohamed Sadek Bachene, Soraya Temim, Hassina Ainbaziz, Asma Bachene

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The present study was conducted to assess the safety and the efficacy of a vaccine containing the Algerian precocious strains of Eimeria magna and Eimeria media used separately or together against rabbit coccidiosis. The samples consisted of 56 young rabbits reared in specific pathogen-free conditions. Following the challenge inoculation, statistically significant decreases in oocyst excretion were noticed in the vaccinated rabbits with the precocious strain of Eimeria magna, Eimeria media, and both species leading toa good immune response acquired by the vaccination associated with a good growth rate. Moreover, there was a statistically significant increase in oocyst output following the challenge in all challenged groups. Unlike the vaccinated groups, the challenged groups showed poor weight gains. More than 50% of the young rabbits from all the challenged groups presented diarrhea. Consequently, these precocious strains constitute good candidates for mono or polyvalent anticoccidial vaccines in the future.

Keywords: precocious strain, rabbits, vaccination, wild strain

Procedia PDF Downloads 66

Authors: Iñaki Iturria, Pasquale Russo, Montserrat Nacher-Vázquez, Giuseppe Spano, Paloma López, Miguel Angel Pardo

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Introduction: It is known that some Lactic Acid Bacteria (LAB) present an interesting probiotic effect. Probiotic bacteria stimulate host resistance to microbial pathogens and thereby aid in immune response, and modulate the host's immune responses to antigens with a potential to down-regulate hypersensitivity reactions. Therefore, probiotic therapy is valuable against intestinal infections and may be beneficial in the treatment of Inflammatory Bowel Disease (IBD). Several in vitro tests are available to evaluate the probiotic potential of a LAB strain. However, an in vivo model is required to understand the interaction between the host immune system and the bacteria. During the last few years, zebrafish (Danio rerio) has gained interest as a promising vertebrate model in this field. This organism has been extensively used to study the interaction between the host and the microbiota, as well as the host immune response under several microbial infections. In this work, we report on the use of the zebrafish model to investigate in vivo the colonizing ability and the immunomodulatory effect of probiotic LAB. Methods: Lactobacillus strains belonging to different LAB species were fluorescently tagged and used to colonize germ-free zebrafish larvae gastrointestinal tract (GIT). Some of the strains had a well-documented probiotic effect (L. acidophilus LA5); while others presented an exopolysaccharide (EPS) producing phenotype, thus allowing evaluating the influence of EPS in the colonization and immunomodulatory effect. Bacteria colonization was monitored for 72 h by direct observation in real time using fluorescent microscopy. CFU count per larva was also evaluated at different times. The immunomodulatory effect was assessed analysing the differential expression of several innate immune system genes (MyD88, NF-κB, Tlr4, Il1β and Il10) by qRT- PCR. The anti-inflammatory effect was evaluated using a chemical enterocolitis zebrafish model. The protective effect against a pathogen was also studied. To that end, a challenge test was developed using a fluorescently tagged pathogen (Vibrio anguillarum-GFP+). The progression of the infection was monitored up to 3 days using a fluorescent stereomicroscope. Mortality rates and CFU counts were also registered. Results and conclusions: Larvae exposed to EPS-producing bacteria showed a higher fluorescence and CFU count than those colonized with no-EPS phenotype LAB. In the same way, qRT-PCR results revealed an immunomodulatory effect on the host after the administration of the strains with probiotic activity. A downregulation of proinflammatory cytoquines as well as other cellular mediators of inflammation was observed. The anti-inflammatory effect was found to be particularly marked following exposure to LA% strain, as well as EPS producing strains. Furthermore, the challenge test revealed a protective effect of probiotic administration. As a matter of fact, larvae fed with probiotics showed a decrease in the mortality rate ranging from 20 to 35%. Discussion: In this work, we developed a promising model, based on the use of gnotobiotic zebrafish coupled with a bacterial fluorescent tagging in order to evaluate the probiotic potential of different LAB strains. We have successfully used this system to monitor in real time the colonization and persistence of exogenous LAB within the gut of zebrafish larvae, to evaluate their immunomodulatory effect and for in vivo competition assays. This approach could bring further insights into the complex microbial-host interactions at intestinal level.

Keywords: gnotobiotic, immune system, lactic acid bacteria, probiotics, zebrafish

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Authors: Mohammad Asadpour, Gholamreza Razmi, Gholamreza Mohammadi, Abolghasem Naghibi

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Cryptosporidium Spp., protozoan parasites of the phylum Apicomplexa, have a wide spectrum of hosts including humans, domestic animals and wild mammals, birds, reptiles, amphibians and fish. Dairy cattle have been identified in numerous reports as a major source of environmental contamination with this pathogen. In this study, a Polymerase Chain Reaction (PCR), Restriction Fragment Length Polymorphism (RFLP) analysis of the Small-Subunit (SSU) rRNA gene was used to detect and identify Cryptosporidium Spp. in 300 fecal specimens from 1 to 30 days pre-wean calves in 10 farms in Mashhad, Iran. Eighty five (28.3%) and forty five (15%) of the specimens were positive for Cryptosporidium by microscopic and PCR examination respectively. Restriction digestion of the PCR products by VSPI and Ssp1 restriction enzymes and analysis of sequence data revealed the presence of C. parvum, bovine genotype in all isolates. Our findings suggest that cattle can be a source of Cryptosporidial infections for humans and animals in Mashhad area. This is the first published description of Cryptosporidium sub genotyping in Mashhad.

Keywords: cryptosporidium, genotype, dairy calves, 18S rRNA, Mashhad

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Authors: Seyed Mehdi Razavi Khosroshahi

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In recent years a great deal of efforts has been made to find natural derivative compounds to replace it's with synthetic drugs, herbicides or pesticides for management of human health and agroecosystem programs. This process can lead to a reduction in environmental harmful effects of synthetic chemicals. Xanthotoxin, as a furanocoumarin compound, found in some genera of the Apiaceae family of plants. The current work focuses on some xanthotoxin cytotoxicity and antipathogenic activities. The results indicated that xanthotoxin showed strong cytotoxic effects against LNCaP cell line with the IC₅₀ value of 0.207 mg/ml in a dose-dependent manner. After treatments of the cell line with 0.1 mg/ml of the compound, the viability of the cells was reached to zero. The current study revealed that xanthotoxin displayed strong antifungal activity against human or plant pathogen fungi, Aspergillus fumigatus, Aspegillusn flavus and Fusarum graminearum with minimum inhibitory concentration values of 52-68 µg/ml. The compound exhibited antibacterial effects on some Erwinia and Xanthomonas species of bacteria, as well

Keywords: Xanthomonas, cytotoxic, antipathogen, LNCaP, Aspergillus fumigatus, spegillusn flavus

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Authors: Sarthak Karki, Haribansha Timalsina

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Kanchan Arsenic Filter is an economical low cost and termed the most efficient arsenic removal filter system in South Asian countries such as Nepal. But when the effluent quality was evaluated, it was seen to possess a lower removal rate of arsenite species. In addition to that, greater pathogenic growth and loss in overall efficacy with time due to precipitation of iron sulphates were the further complications. This brings the health issue on the front line as millions of people rely on groundwater sources for general water necessities. With this paper, we analyzed the mechanisms and changes in the efficiency of the extant filter system when integrated with activated laterite and hair column beds, plus an additional charcoal layer for inhibiting pathogen colonies. Hair column have rich keratin protein that binds with arsenic species, and similarly, raw laterite has huge deposits of iron and aluminum, all of these factors helping to remove heavy metal contaminants from water sources. Further study on the commercialized mass production of the new proposed filter and versatility analysis is required.

Keywords: laterite, charcoal, arsenic removal, hair column

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Authors: Wael Khalil, Elias Rahal, Ghassan Matar

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Tooth related infections or commonly named dental infections have been described as the most common causes of tooth loss in adults. These pathologies were mostly periodontitis, pericoronitis, and periapical infection. The involvement of various bacteria in the pathogenesis of these pathologies has been thoroughly mentioned and approved in the literature. However, the variability in the severity and prognosis of these lesions among patients suggests the association of other pathogens, like viruses and fungi, in the pathogenesis of these lesions. Several studies in the literature investigated the association of multiple viruses and fungi with the above-mentioned lesions, yet, a vast controversy was reached concerning this subject.Aim: Our study aims to fill the gap in the literature concerning the contribution of adenovirus, HPV-16, EBV, fungi, and candida in the pathogenesis of periodontitis, pericoronitis, and periapical infection. For this purpose, we utilized the quantitative PCR for pathogen detection in saliva, gingival, and lesions samples of involved subjects. Results: Some of these pathogens appeared to have an association with the investigated dental pathologies, while others showed no contribution to the pathogenesis of these lesions. Further investigation is required in order to identify the subtype of the involved pathogens in these tooth related oral pathology.

Keywords: periodontitis, pericoronitis, dental abscess, PCR, microbiology

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Authors: Wilailak Siripornadulsil, Siriyanapat Tasaku, Jutamas Buahorm, Surasak Siripornadulsil

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The objectives of this study were to isolate LAB from various sources, dietary supplement, Thai traditional fermented food, and freshwater fish and to characterize their potential as probiotic cultures. Out of 1,558 isolates, 730 were identified as LAB based on isolation on MRS agar supplemented with a bromocresol purple indicator and CaCO3 and gram-positive, catalase and oxidase negative characteristics. Eight isolates showed the potential probiotic properties including tolerance to acid, bile salt and heat, proteolytic, amylolytic and lipolytic activities and oxalate-degrading capability. They all showed the antimicrobial activity against some Gram-negative and Gram-positive pathogenic bacteria. Based on 16S rDNA sequence analysis, they were identified as Enterococcus faecalis BT2 and MG30, Leconostoc mesenteroides SW64 and Pediococcus pentosaceous BD33, CF32, NP6, PS34 and SW5. The health beneficial effects and food safety will be further investigated and developed as a probiotic or protective culture used in Nile tilapia belly flap meat fermentation.

Keywords: probiotic, lactic acid bacteria, pathogen, protective culture

Procedia PDF Downloads 359

Authors: Hoo Cheol Lee, Dae Seung Kim, Sang Myung Jung, Gwang Heum Yoon, Hwa Sung Shin

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Loss of bone tissue can occur due to a bone tissue disease and aging or fracture. Renewable formation of bone is mainly made by its differentiation and metabolism. For this reason, osteoblasts have been studied for regeneration of bone tissue. So, tissue engineering has attracted attention as a recovery means. In tissue engineering, a particularly important factor is a scaffold that supports cell growth. For osteoblast scaffold, we used the cellulose nanowhisker (CNW) extracted from marine organism. CNW is one of an abundant material obtained from a number of plants and animals. CNW is polymer consisting of monomer cellulose and this composition offers biodegradability and biocompatibility to CNW. Mechanical strength of CNW is superior to the existing natural polymers. In addition, substances of marine origin have a low risk of secondary infection by bacteria and pathogen in contrast with those of land-derived. For evaluating its suitability as an osteoblast scaffold, we fabricate CNW film for osteoblast culture and performed the MTT assay and ALP assay to confirm its cytotoxicity and effect on differentiation. Taking together these results, we assessed CNW is a potential candidate of a material for bone tissue regeneration.

Keywords: bone regeneration, cellulose nanowhisker, marine derived material, osteoblast

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Authors: R. A. Lahmer, A. P. Williams, S. Townsend, S. Baker, D. L. Jones

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Chitosan-arginine (Ch-arg) has been proposed as an anti-microbial agent to reduce the proliferation of spoilage and pathogenic bacteria within meat products destined for human consumption. In the current experiment its use as an antimicrobial packaging material was examined. Two different concentrations of chitosan-arginine (0.05 and 0.15 % w/w) were blended into a cellulose film (Ch-arg film). When placed in contact with chicken and beef juice inoculated with a lux-marked strain of E. coli O157, the film incorporating the highest Ch-arg concentration resulted in a small reduction of E. coli O157 in chicken juice; however, there was no effect of the Ch-arg film on E. coli O157 in beef juice. The lack of observed effect in the beef juice experiment we ascribe to insufficient surface-to-surface contact between the film and the bacteria in the beef juice and the greater presence of other Ch-arg reactive components in the juice (e.g. fats, blood cells). Results suggest that, in combination with other anti microbials, Ch-arg packaging may offers some potential for limiting the growth of pathogenic bacteria in foodstuffs; however, further research is needed to enhance their anti-microbial performance.

Keywords: cross-contamination, foodborne pathogen, polymer film, shelf life

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Authors: Asma Afshari, Abdollah Jamshidi, Jamshid Razmyar, Mehrnaz Rad

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Clostridium perfringens is a serious pathogen which causes enteric diseases in domestic animals and food poisoning in humans. Spores can survive cooking processes and play an important role in the possible onset of disease. In this study RAPD-PCR and REP-PCR were used to examine the genetic diversity of 49isolates ofC. Perfringens type A from 3 different sources. The results of RAPD-PCR revealed the most genetic diversity among poultry isolates, while human isolates showed the least genetic diversity. Cluster analysis obtained from RAPD_PCR and based on the genetic distances split the 49 strains into five distinct major clusters (A, B, C, D, and E). Cluster A and C were composed of isolates from poultry meat, cluster B was composed of isolates from human feces, cluster D was composed of isolates from minced meat, poultry meat and human feces and cluster E was composed of isolates from minced meat. Further characterization of these strains by using (GTG) 5 fingerprint repetitive sequence-based PCR analysis did not show further differentiation between various types of strains. To our knowledge, this is the first study in which the genetic diversity of C. perfringens isolates from different types of meats and human feces has been investigated.

Keywords: C. perfringens, genetic diversity, RAPD-PCR, REP-PCR

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Authors: Sehrish Iftikhar, Ahmad Ali Shahid, Kiran Nawaz, Waheed Anwar

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Discovery and development of new compounds require intense studies in chemistry, biochemistry. Numerous experiments under laboratory-, greenhouse- and field conditions can be performed to select suitable candidates and to understand their full potential. Novel fungicides are fundamental to combat plant diseases. Fusarium solani is important plant pathogen. New broad spectrum foliar fungicides against complex II were designed in this study. Complex II, namely succinate dehydrogenase (SDH), or succinate quinone oxidoreductase (SQR) is a multi-subunit enzyme at the crossroads of TCA and ETC at the inner mitochondrial membrane. The need for new and innovative fungicides is driven by resistance management, regulatory hurdles and increasing customer expectations amongst others. Fungicidal activity was assessed for the effect on mycelial growth and spore germination of the fungi using fungicide amended media assay. In mycelial growth assay compounds C10 and C6 were highly active against all the isolates. The compounds C1 and C10 were found most potent in spore germination test. It fully proved that the SDHIs designed in this paper displayed as good inhibitory effects against Fusarium solani.

Keywords: Wilt, Fusarium, SDH, antifungal

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Authors: Mahmoud Mabrok, Channarong Rodkhum

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Flavobacterium columanre is one of the devastating pathogen that causes noticeable economic losses in freshwater cultured fish. Like other filamentous bacteria, F. columanre tends to aggregate and fluctuate to all kind of media, thus revealing obstacles in recognition of its colonies. Since the molecular typing is the only fundamental tool for rapid and precise detection of this pathgen. The present study developed a species-specific PCR assay based on cslA unique gene of F. columnare. The cslA gene sequences of 13 F. columnare, strains retrieved from gene bank database, were aligned to identify a conserved homologous segment prior to primers design. The new primers yielded amplicons of 287 bp from F. columnare strains but not from relevant or other pathogens, unlike to other published set that showed no specificity and cross-reactivity with F. indicum. The primers were sensitive and detected as few as 7 CFUs of bacteria and 3 pg of gDNA template. The sensitivity was reduced ten times when using tissue samples. These primers precisely defined all field isolates in a double-blind study, proposing their applicable use for field detection.

Keywords: Columnaris infection, cslA gene, Flavobacterium columnare, PCR

Procedia PDF Downloads 87

Authors: Zhenfeng Xie

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Acute gastroenteritis (AGE) is a common cause of morbidity and mortality in infants and young children worldwide, especially in developing countries. Enterovirus(EVs) have been identified in patients with AGE in many countries around the world, and some studies have revealed that EV infection is associated with gastrointestinal symptoms and plays a role in AGE. As a potential causative pathogen of AGE in humans, continuous detection and identification of EVs in pediatric patients with AGE is needed. In this study, we aimed to investigate the prevalence, seasonal distribution, and molecular characteristics of EVs circulating in pediatric patients with AGE in Thailand from 2019 to 2022. A total of 1422 stool specimens were collected for this study. RT-PCR amplification of the 5'UTR was used to screen for EV positive samples. EV genotyping was determined based on nucleotide sequence and phylogenetic analysis of the VP1 sequences. EV prevalence in pediatric AGE patients was 8.3% (118 out of 1,422). Among these, 35.6% of EV infection cases were caused by species A, followed by species C and B (33.1% and 30.5%, respectively). A total of 26 EV genotypes were identified in this study. Poliovirus 3 and coxsackievirus A2 were the predominant genotypes detected(14% and 13%, respectively). EV was detected all year round with higher prevalence between July and December. In summary, this study reports EV's prevalence and genotype diversity in pediatric patients with AGE in Thailand during 2019-2022.

Keywords: enterovirus, epidemiology, acute gastroenteritis, genotype

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