Search results for: antimicrobial control

Authors: Recep Kesli, Gulsah Asik, Cengiz Demir, Onur Turkyilmaz

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Objective: Stenotrophomonas maltophilia (S. maltophilia) has recently emerged as an important nosocomial microorganism. Treatment of invasive infections caused by this organism is problematic because this microorganism is usually resistant to a wide range of commonly used antimicrobials. We aimed to evaluate clinical isolates of S. maltophilia in respect to sampling sites and antimicrobial resistant. Method: During a two years period (October 2013 and September 2015) eighteen samples collected from the intensive care unit (ICU) patients hospitalized in Afyon Kocatepe University, ANS Practice and Research Hospital. Identification of the bacteria was determined by conventional methods and automated identification system-VITEK 2 (bio-Mérieux, Marcy l’toile, France). Antibacterial resistance tests were performed by Kirby Bauer disc (Oxoid, England) diffusion method following the recommendations of CLSI. Results: Eighteen S. maltophilia strains were identified as the causative agents of different infections. The main type of infection was lower respiratory tract infection (83,4 %); three patients (16,6 %) had bloodstream infection. While, none of the 18 S. maltophilia strains were found to be resistant against to trimethoprim sulfametaxasole (TMP-SXT) and levofloxacine, eight strains 66.6 % were found to be resistant against ceftazidim. Conclusion: The isolation of S.maltophilia starains resistant to TMP-SXT is vital. In order to prevent or minimize infections due to S. maltophilia such precuations should be utilized: Avoidance of inappropriate antibiotic use, prolonged implementation of foreign devices, reinforcement of hand hygiene practices and the application of appropriate infection control practices. Microbiology laboratories also may play important roles in controlling S. maltophilia infections by monitoring the prevalence, continuously, the provision of local antibiotic resistance paterns data and the performance of synergistic studies also may help to guide appropirate antimicrobial therapy choices.

Keywords: Stenotrophomonas maltophilia, trimethoprim-sulfamethoxazole, antimicrobial resistance, Stenotrophomonas spp.

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Authors: Luiz F. J. Maia

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This paper presents an approach to fuzzy control, with the use of new pertinence functions, applied in the case of an inverted pendulum. Appropriate definitions of pertinence functions to fuzzy sets make possible the implementation of the controller with only one control rule, resulting in a smooth control surface. The fuzzy control system can be implemented with analog devices, affording a true real-time performance.

Keywords: control surface, fuzzy control, Inverted pendulum, pertinence functions

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Authors: Raviv Harris, Maggie Levy

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Natural product-based pesticides may serve as an alternative to the traditional synthetic pesticides, which have a potentially damaging effect, both to human health and for the environment. Along with plants, microorganisms are a prospective source of such biological pesticides. A unique and active strain of P. aphidis (designated isolate L12, Israel 2004), an epiphytic and non-pathogenic basidiomycete yeast, was isolated in our lab from strawberry leaves. P. aphidis L12 secretions were found to inhibit broad range of plant pathogens. This work demonstrates that metabolites isolated from the biocontrol agent P. aphidis (isolate L12) can inhibit varied fungal and bacterial phytopathogens. Biologically active metabolites were extracted from P. aphidis biomass, using the organic solvent ethyl acetate. The antimicrobial activity of the extract was demonstrated, both in vitro and in planta. Using disk diffusion assays, the following inhibition zones were obtained: 43cm² for Pseudomonas syringae pv. tomato, 28.5cm² for Xanthomonas campestris pv. vesicatoria, 59cm² for Clavibacter michiganensis subsp. michiganensis, 34cm² for Erwinia amylovora and 34cm² for Agrobacterium tumefaciens. Additionally, strong inhibitory activity of the extract against fungi mycelial growth was established, with IC₅₀ values of 606µg ml⁻¹ for Botrytis cinerea, 221µg ml⁻¹ for Pythium spp., 519µg ml⁻¹ for Rhizoctonia solani, 455µg ml⁻¹ for Sclerotinia sclerotiorum, 2270µg ml⁻¹ for Fusarium oxysporum f. sp. lycopersici, and 2038µg ml⁻¹ for Alternaria alternata. The results of the in planta experiments demonstrated a dose-dependent reduction in disease infection. Significant inhibition of B. cinerea lesions on tomato plants was obtained when a spore suspension of this pathogen was treated with extract concentrations higher than 4.2mg ml⁻¹. Concentration of 7mg ml⁻¹ caused a reduction of over 95% in the lesion size of B. cinerea on tomato plants. The strong antimicrobial activity demonstrated both in vitro and in planta against varied phytopathogens, may indicate that the extracted antimicrobial metabolites have potential to serve as natural pesticides in the field.

Keywords: antimicrobial, B. cinerea, metabolites, natural pesticides, P. aphidis

Procedia PDF Downloads 212

Authors: Hajir Abdllha, Alaa Mohamed, Khansa Almoniem, Naga Adam, Wdeea Alhaadi, Ahmed Elshikh, Ahmed Ali, Ismail Makuar, Anas Elnazeer, Nagat Elrofaei, Samir Abdoelftah, Monier Hemidan

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The present study was designed to investigate antimicrobial, and antioxidant activities of five species from Acacia (Acacia albidia, Acacia mellifera, Acacia nubica, Acacia seyal var. seyal and Acacia tortilis). Phytochemical study was piloted to detect the bioactive compounds, which have been responsible from the biological activities. The ethanol, chloroform and acetone plant extracts were seasoned against standard bacteria strains of gram +ve bacteria Staphylococcus aureus (ATCC 25923), Gram -ve bacteria Pseudomonas aeruginosa (ATCC 27853) and standard fungi Candida albicans (ATCC 90028), using cup-plate method. The antioxidant activities were conducted via DPPH radical scavenging and metal chelating assays. Prospective activity against the five species was observed in acetone extract. Ethanol extract showed highest activities against Staphylococcus aureus, and Candida albicans. Potential antioxidant activity was presented by ethanol. Cholorophorm and acetone extracts via DPPH, the radical scavenging activities were found to be 91±0.03, 88±0.01 and 85±0.04 respectively. The results of phytochemical screening showed that all extracts of studied plant contain flavonoids, saponins, terpenoids, steroids, alkaloids, phenols and tannins. This study gives rise to antioxidant, antimicrobial properties of studied plant, and showed interesting correlation with the phytochemical constituents and biological activities.

Keywords: antimicrobial, antioxidant, Acacia albidia, Acacia mellifera, Acacia nubica, Acacia seyal var. seyal, Acacia tortilis

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Authors: Pareshkumar Umedbhai Patel

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Variety of microbes were isolated from surface of fruit and vegetables to get idea about normal flora of their surface. The process of isolation of microbes involved use of sterilized cotton swabs to wipe the surface of the samples. For isolation of Bacteria, yeast and fungi microbiological media used were nutrient agar medium, GYE agar medium and MRBA agar medium respectively. The microscopical and macroscopical characteristics of all the isolates were studied. Different plants with known antimicrobial activity were selected for obtaining samples for extraction e.g. Ficus (Ficus religosa) stem, Amla (Phyllanthus emblica) fruit, Tulsi (Ocimum tenuiflorum) leaves and Lemon grass (Cymbopogon citratus) oil. Antimicrobial activity of these samples was tested initially against known bacteria followed by study against microbes isolated from surface of vegetables and fruits. During the studies carried out throughout the work, lemongrass oil and Amla extract were found superior. Lemongrass oil and Amla extract respectively inhibited growth of 65% and 42% microbes isolated from fruit and vegetable surfaces. Rest two studied plant extracts showed only 11% of inhibition against the studied isolates. The results of isolate inhibition show the antibacterial effect of lemongrass oil better than the rest of the studied plant extracts.

Keywords: herbal extracts, vegetables, fruits, antimicrobial activity

Procedia PDF Downloads 135

Authors: Hajir, B. Abdllha, , Alaa, I. Mohamed, Khansa, A. Almoniem, Naga, I. Adam, Wdeea, Alhaadi, Ahmed, A. Elshikh, Ahmed, J. Ali, Ismail, G. Makuar, Anas, M. Elnazeer, Nagat, A. Elrofaei, Samir, F. Abdoelftah, Monier, N. Hemidan

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The present study was designed to investigate antimicrobial, and antioxidant activities of five species from Acacia (Acacia albidia, Acacia mellifera, Acacia nubica, Acacia seyal var.seyal and Acacia tortilis). Phytochemical study was piloted to detect the bioactive compounds, which have been responsible from the biological activities. The ethanol, chloroform and acetone plant extracts were seasoned against standard bacteria strains of gram +ve bacteria Staphylococcus aureus (ATCC 25923) ,Gram -ve bacteria Pseudomonas aeruginosa (ATCC 27853) and standard fungi Candida albicans (ATCC 90028), using cup-plate method. The antioxidant activities were conducted via DPPH radical scavenging and metal chelating assays. Prospective activity against the five species was observed in acetone extract. Ethanol extract showed highest activities against Staphylococcus aureus, and Candida albicans. Potential antioxidant activity was presented by ethanol. Cholorophorm and acetone extracts via DPPH, the radical scavenging activities were found to be 91±0.03, 88±0.01 and 85±0.04 respectively. The results of phytochemical screening showed that all extracts of studied plant contain flavonoids, saponins, terpenoids, steroids, alkaloids, phenols and tannins. This study give rise to antioxidant, antimicrobial properties of studied plant, and showed interesting correlation with the phytochemical constituents and biological activities.

Keywords: antimicrobial, Antioxidant, Acacia albidia, Acacia mellifera, acacia nubica, acacia seyal var.seyal, Acacia tortilis

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Authors: Norhan H. Mahdally, Bathini Thissera Riham A. ElShiekh, Noha M. Elhosseiny, Mona T. Kashef, Ali M. El Halawany, Mostafa E. Rateb, Ahmed S. Attia

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Multidrug-resistant (MDR) pathogens pose a global threat to healthcare settings. The exhaustion of the current antibiotic arsenal and the scarcity of new antimicrobials in the pipeline aggravate this threat and necessitate a prompt and effective response. This study focused on two major pathogens that can cause serious infections: carbapenem-resistant Acinetobacter baumannii (CRAB) and methicillin-resistant Staphylococcus aureus (MRSA). Multiple soil isolates were collected from several locations throughout Egypt and screened for their conventional and non-conventional antimicrobial activities against MDR pathogens. One isolate exhibited potent antimicrobial activity and was subjected to multiple rounds of fractionation. After fermentation and bio-guided fractionation, we identified pure microbial secondary metabolites with two scaffolds that exhibited promising effects against CRAB and MRSA. Scaling up and chemical synthesis of derivatives of the identified metabolite resulted in obtaining a more potent derivative, which we designated as 2HP. Cytotoxicity studies indicated that 2HP is well-tolerated by human cells. Ongoing work is focusing on formulating the new compound into a nano-formulation to enhance its delivery. Also, to have a better idea about how this compound works, a proteomic approach is currently underway. Our findings suggest that 2HP is a potential new broad-spectrum antimicrobial agent. Further studies are needed to confirm these findings and to develop 2HP into a safe and effective treatment for MDR infections.

Keywords: broad-spectrum antimicrobials, carbapenem-resistant acinetobacter baumannii, drug discovery, methicillin-resistant staphylococcus aureus, multidrug-resistant, natural products

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Authors: Baluku Nathan

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Infection prevention and control (IPC) is a practical, evidence-based approach that prevents patients and emergency health workers from being harmed by avoidable infections as a result of antimicrobial resistance; all hospital infection control programs put together various practices which, when used appropriately, restrict the spread of infection. A breach in these control practices facilitates the transmission of infections from patients to health workers, other patients, and attendants. It is, therefore important for all emergency medical technicians (EMTs) and patients to strictly adhere to them. It is also imperative for administrators to ensure the implementation of the infection control programme for their facilities. Purpose: The purpose of this study was to investigate the influencing factors of prevention practices against infection exposure among emergency medical technicians (EMTs) in the emergency department at Mbarara hospital. Methodology: This was a descriptive cross-sectional study that employed a self-reported questionnaire that was filled out by 32 EMTs in the emergency department from 12th February to 3rd march 2022. The questionnaire consisted of items concerning the defensive environment and other factors influencing infection prevention and control practices in the accident and emergency department of Mbarara hospital. Results: From the findings, the majority 16 (50%) always used protective gear when doing clinical work, 14 (43.8%) didn’t use protective gear, citing they were only assisting those performing resuscitations, gumboots were the least used protective gear with only3(9.4%) usage. About disposal techniques of specific products like blood and sharps, results showed 10 (31.3%) said blood is disposed of in red buckets, 5 (15.6%) in yellow buckets, and only 5(15.6%) in black buckets, and 12(37.5%) didn’t respond, however, 28(87.5%) said sharps were disposed of in a sharps container. The majority, 17 (53.1%), were not aware of the infection control guidelines even though they were pinned on walls of the emergency rooms, 15(46.9%) said they have never had quality assurance monitoring events, 14(43.8%) said monitoring was continuous while 15(46.9 %) said it was discrete. Conclusions: The infection control practices at the emergency department were inadequate in view of less than 100% of the EMTs observing the five principles of infection prevention, such as the use of personal protective equipment and proper waste disposal in appropriate color-coded bins. Dysfunctional infection prevention and control committees accompanied by inadequate supervision to ensure infection control remained a big challenge.

Keywords: emergency medical technician, infection prevention, influencing factors, infection control

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Authors: I. Nanako, Mariko Era, Hiroshi Morita

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Objectives: Japanese uses TATAMI rather than flooring at home. Igusa ( Juncus effuses var. decipiens ), which is commonly known in the forms of TATAMI. Juncus spp. grow at a relatively high humidity area (Japan, China and Southeast Asia ). Yatsushiro region in the southern part of Kumamoto prefecture is major produing area of Igusa. Igusa found to have honeycomb structure and was also shown to have the ability to control humidity. And Igusa has been used as a medicinal herb for diuretic and antiphlogistic agent. In previous study, we investigated antimicrobial effects of Igusa, and showed high antimicrobial activity against food poisoning bacteria. Therefore, the food trays blended Igusa can be kept clean by antimicrobial activity of Igusa. We focus on ‘Igusa foam materials’. In this study, we investigated the antibacterial and antifungal activity of Igusa, and new application to foam materials for food industry. Materials and method: We used Igusa foam materials (3 × 3 × 3 cm) as a sample. We set about fifteen types of samples combined with a commercial antibacterial agent A, a commercial antibacterial agent B, potassium laurate (C12K) and a commercial antifungal agent C, a commercial antifungal agent D and a commercial antifungal agent E. We selected four bacteria strains (Escherichia coli NBRC 3972, Staphylococus aureus NBRC 12732, Salmonella typhimurium NBRC 13245, Bacillus subtilis NBRC 3335 ) and three fungus strains (Penicillium pinophilum NBRC 6345, Cladosporium cladosporioides NBRC 30314, Aspergillus oryzae NBRC 5238 ). The fungus was cultured at 30 °C on Igusa foam materials after inoculation of the fungus for fourteen days. The bacteria was cultured at 30 °C on Igusa foam materials after inoculation of the bacteria for three days. And the Igusa foam materials were washed with 10 mL normal saline after three days. The normal saline washed Igusa foam materials plated the NA medium. After, It was cultured at 30 °C and used colony counting method. Result and Conclusion: The fifteen types of sample of Igusa foam materials had antifungal activity against C. cladosporioides, A. oryzae and P. pinophilum for fourteen days. The four types of sample contained potassium laurate and antibacterial agent A, sample contained antibacterial agent B and antifungal agent D, sample contained A and antifungal agent E, sample contained B and E had antibacterial activity against B. subtilis. The three types of sample contained potassium laurate and A, sample contained B and D, sample contained A and E had antibacterial activity against S. typhimurium. The five types of sample contained potassium laurate and A, sample contained B and D, sample contained A and E, sample contained B and E, sample contained B and antifungal agent C had antibacterial activity against E. coli and S. aureus. These results indicate that Igusa of Igusa foam materials had high antifungal activity. In addition, Igusa foam materials combined with a commercial antibacterial agent had antibacterial activity. In the future, we consider that use of Igusa foam materials may be spread from food industry.

Keywords: antibacterial, antifungal, foam materials, Igusa

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Authors: Khaing Yadana Swe, Lillie Dewan

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At present, the cascade PID control is widely used to control the super-heating temperature (main steam temperature). As the main steam temperature has the characteristics of large inertia, large time-delay, and time varying, etc., conventional PID control strategy can not achieve good control performance. In order to overcome the bad performance and deficiencies of main steam temperature control system, Model Free Adaptive Control (MFAC) P cascade control system is proposed in this paper. By substituting MFAC in PID of the main control loop of the main steam temperature control, it can overcome time delays, non-linearity, disturbance and time variation.

Keywords: model-free adaptive control, cascade control, adaptive control, PID

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Authors: Hasan Demiroğlu, Uğur Avcıbaşı, Serhan Sakarya, Perihan Ünak

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Implanted devices are progressively practiced in innovative medicine to relieve pain or improve a compromised function. Implant-associated infections represent an emerging complication, caused by organisms which adhere to the implant surface and grow embedded in a protective extracellular polymeric matrix, known as a biofilm. In addition, the microorganisms within biofilms enter a stationary growth phase and become phenotypically resistant to most antimicrobials, frequently causing treatment failure. In such cases, surgical removal of the implant is often required, causing high morbidity and substantial healthcare costs. Staphylococcus aureus is the most common pathogen causing implant-associated infections. Successful treatment of these infections includes early surgical intervention and antimicrobial treatment with bactericidal drugs that also act on the surface-adhering microorganisms. Linezolid is a promising anti-microbial with ant-staphylococcal activity, used for the treatment of MRSA infections. Linezolid is a synthetic antimicrobial and member of oxazolidinoni group, with a bacteriostatic or bactericidal dose-dependent antimicrobial mechanism against gram-positive bacteria. Intensive use of antibiotics, have emerged multi-resistant organisms over the years and major problems have begun to be experienced in the treatment of infections occurred with them. While new drugs have been developed worldwide, on the other hand infections formed with microorganisms which gained resistance against these drugs were reported and the scale of the problem increases gradually. Scientific studies about the production of bacterial biofilm increased in recent years. For this purpose, we investigated the activity of Lin, Lin radiolabeled with 131I (131I-Lin) and cold iodinated Lin (127I-Lin) against clinical strains of Staphylococcus aureus DSM 4910 in biofilm. In the first stage, radio and cold labeling studies were performed. Quality-control studies of Lin and iodo (radio and cold) Lin derivatives were carried out by using TLC (Thin Layer Radiochromatography) and HPLC (High Pressure Liquid Chromatography). In this context, it was found that the binding yield was obtained to be about 86±2 % for 131I-Lin. The minimal inhibitory concentration (MIC) of Lin, 127I-Lin and 131I-Lin for Staphylococcus aureus DSM 4910 strain were found to be 1µg/mL. In time-kill studies of Lin, 127I-Lin and 131I-Lin were producing ≥ 3 log10 decreases in viable counts (cfu/ml) within 6 h at 2 and 4 fold of MIC respectively. No viable bacteria were observed within the 24 h of the experiments. Biofilm eradication of S. aureus started with 64 µg/mL of Lin, 127I-Lin and 131I-Lin, and OD630 was 0.507±0.0.092, 0.589±0.058 and 0.266±0.047, respectively. The media control of biofilm producing Staphylococcus was 1.675±0,01 (OD630). 131I and 127I did not have any effects on biofilms. Lin and 127I-Lin were found less effectively than 131I-Lin at killing cells in biofilm and biofilm eradication. Our results demonstrate that the 131I-Lin have potent anti-biofilm activity against S. aureus compare to Lin, 127I-Lin and media control. This is suggested that, 131I may have harmful effect on biofilm structure.

Keywords: iodine-131, linezolid, radiolabeling, slime layer, Staphylococcus

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Authors: A. Abbasi Moshaii, M. Soltan Rezaee, M. Mohammadi Moghaddam

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Control of some mechanisms is hard because of their complex dynamic equations. If part of the complexity is resulting from uncertainties, an efficient way for solving that is robust control. By this way, the control procedure could be simple and fast and finally, a simple controller can be designed. One kind of these mechanisms is 3-RRR which is a parallel mechanism and has three revolute joints. This paper aims to robust control a 3-RRR planner mechanism and it presents that this could be used for other mechanisms. So, a significant problem in mechanisms control could be solved. The relevant diagrams are drawn and they show the correctness of control process.

Keywords: 3-RRR, dynamic equations, mechanisms control, structural uncertainty

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Authors: Alia Abdul Ghaffar, Tom Richardson

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A model reference adaptive control and a fixed gain LQR control were implemented in the height controller of a quadrotor that has parametric uncertainties due to the act of picking up an object of unknown dimension and mass. It is shown that an adaptive control, unlike a fixed gain control, is capable of ensuring a stable tracking performance under such condition, although adaptive control suffers from several limitations. The combination of both adaptive and fixed gain control in the controller architecture results in an enhanced tracking performance in the presence of parametric uncertainties.

Keywords: UAV, quadrotor, robotic arm augmentation, model reference adaptive control, LQR control

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Authors: S. Pooja Pragati, B. Sudarsan, S. Rajkumar

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Silver nanoparticles (AgNP) are known for their excellent antimicrobial agents, and thus can be used as alternative disinfectant agents. However, released silver nanoparticles is a threat to naturally occurring microorganisms. This paper exhibits information on the environmental fate, toxicological effects, and application of AgNP and the current estimate on the physicochemical and antimicrobial properties of AgNP in different aqueous solutions, as well as their application as alternative disinfectants in water-treatment systems. It also gives a better approximation and experimental data of AgNP’s antimicrobial properties at different water chemistry conditions. A saturation-type fitting curve was established, showing the survival of bacteria under different water chemistry conditions as a function of the size of the nanoparticles. The results obtained show that silver nanoparticles in surface water, ground water, and brackish water are stable. The paper demonstrates the comparative study of AgNP-impregnated point-of-use ceramic water filters and ceramic filters impregnated with silver nitrate. It is observed that AgNP-impregnated ceramic water filters are more appropriate for this application due to the lesser amount of silver desorbed. Experimental data of the comparison of a polymer-based quaternary amine functionalized silsesquioxanes compound and AgNP are also tabulated and conclusions are analysed with the goal of optimizing. The simplicity of synthesis and application of Silver nanoparticles enables us to consider its effective modified version for the purification of water.

Keywords: disinfectant agent, purification of water, nano particles, water treatment

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Authors: Aya Tanaka, Mariko Era, Shiho Sakai, Takayoshi Kawahara, Takahide Kanyama, Hiroshi Morita

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Objectives: Aspergillus niger and Aspergillus oryzae are used as koji fungi in the spot of the brewing. Since koji-muro (room for making koji) was a low level of airtightness, microbial contamination has long been a concern to the alcoholic beverage production. Therefore, we focused on the fatty acid salt which is the main component of soap. Fatty acid salts have been reported to show some antibacterial and antifungal activity. So this study examined antimicrobial activities against Aspergillus and Bacillus spp. This study aimed to find the effectiveness of the fatty acid salt in koji-muro as antimicrobial agents. Materials & Methods: A. niger NBRC 31628, A. oryzae NBRC 5238, A. oryzae (Akita Konno store) and Bacillus subtilis NBRC 3335 were chosen as tested. Nine fatty acid salts including potassium butyrate (C4K), caproate (C6K), caprylate (C8K), caprate (C10K), laurate (C12K), myristate (C14K), oleate (C18:1K), linoleate (C18:2K) and linolenate (C18:3K) at 350 mM and pH 10.5 were used as antimicrobial activity. FASs and spore suspension were prepared in plastic tubes. The spore suspension of each fungus (3.0×104 spores/mL) or the bacterial suspension (3.0×105 CFU/mL) was mixed with each of the fatty acid salts (final concentration of 175 mM). The mixtures were incubated at 25 ℃. Samples were counted at 0, 10, 60, and 180 min by plating (100 µL) on potato dextrose agar. Fungal and bacterial colonies were counted after incubation for 1 or 2 days at 30 ℃. The MIC (minimum inhibitory concentration) is defined as the lowest concentration of drug sufficient for inhibiting visible growth of spore after 10 min of incubation. MICs against fungi and bacteria were determined using the two-fold dilution method. Each fatty acid salt was separately inoculated with 400 µL of Aspergillus spp. or B. subtilis NBRC 3335 at 3.0 × 104 spores/mL or 3.0 × 105 CFU/mL. Results: No obvious change was observed in tested fatty acid salts against A. niger and A. oryzae. However, C12K was the antibacterial effect of 5 log-unit incubated time for 10 min against B. subtilis. Thus, C12K suppressed 99.999 % of bacterial growth. Besides, C10K was the antibacterial effect of 5 log-unit incubated time for 180 min against B. subtilis. C18:1K, C18:2K and C18:3K was the antibacterial effect of 5 log-unit incubated time for 10 min against B. subtilis. However, compared to saturated fatty acid salts to unsaturated fatty acid salts, saturated fatty acid salts are lower cost. These results suggest C12K has potential in the field of koji-muro. It is necessary to evaluate the antimicrobial activity against other fungi and bacteria, in the future.

Keywords: Aspergillus, antimicrobial, fatty acid salts, koji-muro

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Authors: Maryam Rahimi, Maryam Moslehishad, Seyede Marzieh Hosseini

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In this study, preparation of spray dried Carum copticum essential oil (CCEO)-loaded microcapsules by maltodextrin and its blending with two other natural biodegradable polymers, gum Arabic (GA) or modified starch (MS) were investigated. Addition of these polymers to maltodextrin resulted in the encasement of encapsulation efficiency (EE). The highest EE (78.22±0.34%) and total phenolic (TP) content (83.86±1.72 mg GAE/100g) was related to MD-MS microcapsules. CCEO-loaded microcapsules showed spherical surface, good antioxidant and antimicrobial properties. In addition, sensory tests confirmed the possible application of CCEO-loaded microcapsules as natural food additives.

Keywords: carum copticum, essential oil, encapsulation, spray drying, sensory evaluation, antioxidants

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Authors: Mohammed Sabbah, Asmaa Al-Asmar, Doaa Abu-Hani, Fuad Al-Rimawi

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Plant extracts are an increasingly popular natural product with a wide range of potential applications in food, industrial, and health care industries. They are rich in polyphenolic compounds and flavonoids, which have been demonstrated to possess a variety of beneficial properties, including antimicrobial and antioxidant activity. Plant extracts have been found to possess antimicrobial activity against a variety of foodborne pathogens and can be used as a natural preservative to extend the shelf life of food products. They have also strong antioxidant activity, which can reduce the formation of free radicals and oxidation of food components. Recently there is an increase interest in bio-based polymers to be used as innovative “bioplastics” for industrial exploitation e.g. packaging materials for food products. Additionally, incorporation of active compounds (e.g. antioxidants and antimicrobials) in bio-polymer materials is of particular interest since such active polymers can be used as active packaging materials (with antimicrobial and antioxidant activity). In this work, different plant extracts have been characterized for their phenolic compounds, flavonoids content, antioxidant activity (both as free radical scavenging ability and reducing ability), and antimicrobial activity against gram positive and negative bacteria (Escherichia coli; Staphylococcus aureus, and Pseudomonas aeruginosa) as well as antifungal activities (against yeast, mold and Botrytis cinera/a plant pathogen). Results showed that many extracts are rich with polyphenolic compounds and flavonoids and have strong antioxidant activities, and rich with phytochemicals (e.g. rutin, quercetin, oleuropein, tyrosol and hydroxytyrosol). Some extracts showed antibacterial activity against both gram positive and negative bacteria as well as antifungal activities and can work, therefore, as preservatives for food or pharmaceutical industries. As an application, two extracts were used as additive to pectin-based packaging film, and results showed that the addition of these extracts significantly improve their functionality as antimicrobial and antioxidant activity. These biomaterials, therefore can be used in food packaging materials to extend the shelf life of food products.

Keywords: plant extracts, antioxidants, flavonoids, bioplastic, edible biofilm, packaging materials

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Authors: Farideh Namvar, Rosfarizan Mohamed

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In the field of nanotechnology, the use of various biological units instead of toxic chemicals for the reduction and stabilization of nanoparticles, has received extensive attention. This use of biological entities to create nanoparticles has designated as “Green” synthesis and it is considered to be far more beneficial due to being economical, eco-friendly and applicable for large-scale synthesis as it operates on low pressure, less input of energy and low temperatures. The lack of toxic byproducts and consequent decrease in degradation of the product renders this technique more preferable over physical and classical chemical methods. The variety of biomass having reduction properties to produce nanoparticles makes them an ideal candidate for fabrication. Metal oxide nanoparticles have been said to represent a "fundamental cornerstone of nanoscience and nanotechnology" due to their variety of properties and potential applications. However, this also provides evidence of the fact that metal oxides include many diverse types of nanoparticles with large differences in chemical composition and behaviour. In this study, iron oxide nanoparticles (Fe3O4-NPs) were synthesized using a rapid, single step and completely green biosynthetic method by reduction of ferric chloride solution with brown seaweed (Sargassum muticum) water extract containing polysaccharides as a main factor which acts as reducing agent and efficient stabilizer. Antimicrobial activity against six microorganisms was tested using well diffusion method. The resulting S-IONPs are crystalline in nature, with a cubic shape. The average particle diameter, as determined by TEM, was found to be 18.01 nm. The S-IONPs were efficiently inhibited the growth of Listeria monocytogenes, Escherichia coli and Candida species. Our favorable results suggest that S-IONPs could be a promising candidate for development of future antimicrobial therapies. The nature of biosynthesis and the therapeutic potential by S-IONPs could pave the way for further research on design of green synthesis therapeutic agents, particularly nanomedicine, to deal with treatment of infections. Further studies are needed to fully characterize the toxicity and the mechanisms involved with the antimicrobial activity of these particles. Antioxidant activity of S-IONPs synthesized by green method was measured by ABTS (2, 2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (IC50= 1000µg) radical scavenging activity. Also, with the increasing concentration of S-IONPs, catalase gene expression compared to control gene GAPDH increased. For anti-angiogenesis study the Ross fertilized eggs were divided into four groups; the control and three experimental groups. The gelatin sponges containing albumin were placed on the chorioalantoic membrane and soaked with different concentrations of S-IONPs. All the cases were photographed using a photo stereomicroscope. The number and the lengths of the vessels were measured using Image J software. The crown rump (CR) and weight of the embryo were also recorded. According to the data analysis, the number and length of the blood vessels, as well as the CR and weight of the embryos reduced significantly compared to the control (p < 0.05), dose dependently. The total hemoglobin was quantified as an indicator of the blood vessel formation, and in the treated samples decreased, which showed its inhibitory effect on angiogenesis.

Keywords: anti-angiogenesis, antimicrobial, antioxidant, biosynthesis, iron oxide (fe3o4) nanoparticles, sargassum muticum, seaweed

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Authors: Yener Tekeli, Hayri Baba

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The natural active compounds found in medicinal plants are belong to various chemical structures including polyphenolic compounds, flavonoids, essential oils, and vitamins and some of these compounds have anticancer, antioxidant, and antimicrobial activity. However, these compounds have been little known about mechanisms to confer antibacterial drug resistance. In this study; some macrofungi extracts (Pholiota lucifera, Gnaoderma applanatum and Pleurotus ostreatus) were investigated for their abilities to enhance bacterial permeability by flow cytometry. This experiments exhibited enhancement of these extracts to disrupt the cytoplasmic membrane of living bacterial (Listeria innocua and Escherichia coli) cells. These experiments were designed to detect uptake of PI&SYT by enhancing with a ranged concentration of herb extracts.

Keywords: antimicrobial activity, flow cytometry, macrofungi, multidrug resistant

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Authors: Nahla Elsherbiny, Ahmed Ahmed, Hamada Mohammed, Mohamed Ali

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Background: The enterococci may be considered as opportunistic agents particularly in immunocompromised patients. It is one of the top three pathogens causing many healthcare associated infections (HAIs). Resistance to several commonly used antimicrobial agents is a remarkable characteristic of most species which may carry various genes contributing to virulence. Objectives: to determine the prevalence of enterococci species in different intensive care units (ICUs) causing health care-associated infections (HAIs), intestinal carriage and environmental contamination. Also, to study the antimicrobial susceptibility pattern of the isolates with special reference to vancomycin resistance. In addition to phenotypic and genotypic detection of gelatinase, cytolysin and biofilm formation among isolates. Patients and Methods: This study was carried out in the infection control laboratory at Assiut University Hospitals over a period of one year. Clinical samples were collected from 285 patients with various (HAIs) acquired after admission to different ICUs. Rectal swabs were taken from 14 cases for detection of enterococci carriage. In addition, 1377 environmental samples were collected from the surroundings of the patients. Identification was done by conventional bacteriological methods and confirmed by analytical profile index (API). Antimicrobial sensitivity testing was performed by Kirby Bauer disc diffusion method and detection of vancomycin resistance was done by agar screen method. For the isolates, phenotypic detection of cytolysin, gelatinase production and detection of biofilm by tube method, Congo red method and microtiter plate. We performed polymerase chain reaction (PCR) for detection of some virulence genes (gelE, cylA, vanA, vanB and esp). Results: Enterococci caused 10.5% of the HAIs. Respiratory tract infection was the predominant type (86.7%). The commonest species were E.gallinarum (36.7%), E.casseliflavus (30%), E.faecalis (30%), and E.durans (3.4 %). Vancomycin resistance was detected in a total of 40% (12/30) of those isolates. The risk factors associated with acquiring vancomycin resistant enterococci (VRE) were immune suppression (P= 0.031) and artificial feeding (P= 0.008). For the rectal swabs, enterococci species were detected in 71.4% of samples with the predominance of E. casseliflavus (50%). Most of the isolates were vancomycin resistant (70%). Out of a total 1377 environmental samples, 577 (42%) samples were contaminated with different microorganisms. Enterococci were detected in 1.7% (10/577) of total contaminated samples, 50% of which were vancomycin resistant. All isolates were resistant to penicillin, ampicillin, oxacillin, ciprofloxacin, amikacin, erythromycin, clindamycin and trimethoprim-sulfamethaxazole. For the remaining antibiotics, variable percentages of resistance were reported. Cytolysin and gelatinase were detected phenotypically in 16% and 48 % of the isolates respectively. The microtiter plate method showed the highest percentages of detection of biofilm among all isolated species (100%). The studied virulence genes gelE, esp, vanA and vanB were detected in 62%, 12%, 2% and 12% respectively, while cylA gene was not detected in any isolates. Conclusions: A significant percentage of enterococci was isolated from patients and environments in the ICUs. Many virulence factors were detected phenotypically and genotypically among isolates. The high percentage of resistance, coupled with the risk of cross transmission to other patients make enterococci infections a significant infection control issue in hospitals.

Keywords: antimicrobial resistance, enterococci, ICUs, virulence factors

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Authors: Baluku Nathan

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Infection prevention and control (IPC) is a practical, evidence-based approach that prevents patients and emergency health workers from being harmed by avoidable infections as a result of antimicrobial resistance; all hospital infection control programs put together various practices which, when used appropriately, restrict the spread of infection. A breach in these control practices facilitates the transmission of infections from patients to health workers, other patients and attendants. It is, therefore, important for all EMTs and patients to adhere to them strictly. It is also imperative for administrators to ensure the implementation of the infection control program for their facilities. Purpose: The purpose of this study was to investigate the influencing factors of prevention practices against Infection exposure among emergency medical technicians (EMTs) in the emergency department at Mbarara hospital. Methodology: This was a descriptive cross-sectional study that employed a self-reported questionnaire that was filled out by 32 EMTs in the emergency department from 12th February to 3rd march 2022. The questionnaire consisted of items concerning the defensive environment and other Factors influencing Infection prevention and control practices in the accident and emergency department of Mbarara hospital. Results: From the findings, majority16(50%) always used protective gear when doing clinical work,14 (43.8%) didn’t use protective gear, citing they were only assisting those performing resuscitations, gumboots were the least used protective gear with only3(9.4%) usage. Regarding disposal techniques of specific products like blood and sharps, results showed 10 (31.3%) said blood is disposed of in red buckets, 5(15.6%) in yellow buckets and only5(15.6%) in black buckets and 12(37.5%) didn’t respond. However, 28(87.5%) said sharps were disposed of in a sharps container. The majority, 17(53.1%), were not aware of the infection control guidelines even though they were pinned on walls of the emergency rooms,15(46.9%) said they had never had quality assurance monitoring events,14(43.8%) said monitoring was continuous while15(46.9 %) said it was discrete. Conclusions: The infection control practices at the emergency department were inadequate in view of less than 100% of the EMTs observing the five principles of infection prevention, such as the use of personal protective equipment and proper waste disposal in appropriate color-coded bins. Dysfunctional infection prevention and control committees accompanied by inadequate supervision to ensure infection control remained a big challenge.

Keywords: infection prevention, influencing factors, emergency medical technician (EMT), emergency unit

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Authors: Mujeeb Mohd, Aqil Mohd, A. K. Najmi, Akhtar MMohd, Vasim Mohd

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Dioscorea deltoidea belongs to the Dioscoreaceae family, is usually found in the north-western Himalayas and some other parts of the world up to an altitude of 1000–3000 m. D. deltoidea commonly known as yam and is an extensively used medicinal plant in the indigenous system of medicine. It has been reported to contain dioscine a steroidal glycoside in higher concentration. In the present investigation, silver nanoparticles (AgNPs) have been synthesized by a simple, efficient, environmentally benevolent and economic microwave-assisted method. Callus culture of D. deltoidea was developed and maintained on Murashige and skooge basal medium supplemented with different combination and concentration of plant growth regulators. Aqueous extract of callus culture was used as the reducing and stabilizing agent. The synthesized nanoparticles have been characterized by UV–Vis spectroscopy, Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and X-ray diffraction (XRD analysis. The presence of a characteristic surface plasmon resonance (SPR) absorption band at 430 nm in UV–Vis reveals the reduction of silver metal ions into silver nanoparticles. Whereas FTIR analysis was performed to probe the possible functional group involved in the synthesis of AgNPs. Further extract and AgNPs were evaluated for antimicrobial activity against different pathogenic microorganisms.

Keywords: antimicrobial, Dioscorea deltoidea, microwave, silver, nanoparticles

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Authors: M. Raissy, M. Shahrani

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The present study was done to evaluate the presence of tetracycline resistance genes in Lactococcus garvieae isolated from cultured rainbow trout, West Iran. The isolates were examined for antimicrobial resistance using disc diffusion method. Of the 49 strains tested, 19 were resistant to tetracycline (38.7%), 32 to enrofloxacin (65.3%), 21 to erythromycin (42.8%), 20 to chloramphenicol and trimetoprim-sulfamethoxazole (40.8%). The strains were then characterized for their genotypic resistance profiles. The results revealed that all 49 isolates contained at least one of the tetracycline resistance genes. Tet (A) was found in 89.4% of tetracycline resistant isolates and the frequency of other gene were as follow: tet (E) 42.1%, tet (B) 47.3%, tet (D) 15.7%, tet (L) 26.3%, tet (K) 52.6%, tet (G) 36.8%, tet (34) 21%, tet (S) 63.1%, tet (C) 57.8%, tet (M) 73.6%, tet (O) 42.1%. The results revealed high levels of antibiotic resistance in L. garvieae strains which is a potential danger for trout culture as well as for public health.

Keywords: Lactococcus garvieae, tetracycline resistance genes, rainbow trout, antimicrobial resistance

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Authors: S. M. Abd-Altwab, M. R. Noor El-Din

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This paper aims to the synthesis of new ethoxylated amide as bactericides to prevent the growth of Gram +ve and –ve bacteria of water-in-diesel fuel nanoemulsions over a long period of time as three months. To realize it, eight kinetically stable water-in-diesel fuel nanoemulsions differing in surfactant concentrations and water contents ranging from 4 to 8 and 5 to 8 wt.,wt.,% of total weight of the nanoemulsions, respectively were formed at a temperature of 20 °C. The performance of this ethoxylated amide as bactericides agents against two strains of Gram-negative bacteria, namely, Pseudomonas aeruginosa and Escherichia coli, and two strains of Gram-positive bacteria namely, Staphylococcus aureus and Bacillus subtilis, were evaluated as antimicrobial agents. The maximum and minimum antimicrobial activities were 85 and 71 % against S. aureus and E. coli, respectively, at a concentration of 5 mg/l, pH 7, and 37 °C.

Keywords: nanoemulsion, bacteriocide, diesel fuel, emulsifier

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Authors: Minhas Alam, Muhammad Hidayat Rasool, Mohsin Khurshid, Bilal Aslam

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Acinetobacter baumannii is a notorious bacterial pathogen that is an emerging nightmare in clinical settings and is mainly involved in severe nosocomial infections. However, the data related to carbapenem-resistant A. baumannii (CRAB) from veterinary settings is limited, especially in developing countries like Pakistan. To investigate the genetic diversity and molecular basis of carbapenem resistance in Acinetobacter baumannii isolates from Cattle, a total of 1960 samples were collected from cattle from Punjab, Pakistan. The isolates were analyzed by routine microbiological procedures and confirmed by polymerase chain reaction (PCR). The isolates were further screened for antimicrobial susceptibility and the presence of multiple antimicrobial-resistant determinants by PCR. Multilocus sequence typing (MLST) was performed. The results of the current study revealed that the overall prevalence of A. baumannii in cattle was 3.28% (65/1980). Among cattle 27.7% (18/65) were found CRAB strains. The CRAB isolates harbor class D β- lactamases genes, e-g, blaOXA-23 and blaOXA-51, 94.4% (17/18). CRAB isolates carry class B β- lactamases gene blaIMP, and only one isolate carries the blaNDM-1 gene. The MLST results of CRAB isolates from cattle demonstrated 5 STs and one new ST. The commonly found sequence types in CRAB isolates were ST2 (n=10, 55.5%), followed by ST642 (n=5, 27.8%) and ST600 & ST889 (n=1, 5.55%). The presence of CRAB isolates in cattle indicates an alarming situation in Punjab, Pakistan. Immediate control measures should be taken to stop the transmission of CRAB isolates within cattle, to the environment, and to clinical settings.

Keywords: acinetobacter baumannii, carbapenemases, veterinary, drug resistance

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Authors: Daria Reczynska, Justyna Jarczak, Michal Czopowicz, Danuta Sloniewska, Karina Horbanczuk, Wieslaw Jarmuz, Jaroslaw Kaba, Emilia Bagnicka

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Since people, animals and plants are constantly exposed to pathogens they have developed very complex systems of defense. Among ca. 1000 antimicrobial peptides from different families so far identified, approximately 30 belonging to cathelicidin family can be found in mammals. Cathelicidins probably constitute the first line of defense because they can act at a physiological salt concentration which is present in healthy tissues. Moreover, the low salt concentration which is present in infected tissues inhibits their activity. In goat bactenecin 7.5 (BAC7.5), bactenecin 5 (BAC5), myeloid antimicrobial peptide 28 (MAP28), myeloid antimicrobial peptide 34 (MAP34 A and B), goat bactenecin3.4 (ChBac3.4) were identified. Caprine arthritis-encephalitis (CAE) caused by small ruminant lentivirus (SRLV) is economic problem. The main CAE symptoms are weight loss, arthritis, pneumonia and mastitis (significant elevation of the somatic cell count and deterioration of some technological parameters). The study was conducted on 24 dairy goats. The animals were divided into two groups: experimental (SRLV-infected) and control (non-infected). The blood samples were collected five times: on the 1st, 7th, 30th, 90th and 150thday of lactation. The levels of transcripts of BAC7.5, BAC5, MAP28 and MAP34 genes in blood leucocytes were measured using qPCR method. There were no differences in mRNA levels of studied genes between stages of lactation. The differences were observed in expressions of BAC5, MAP28 and MAP34 genes with lower levels in the experimental group. There was no difference in BAC7.5 expression between groups. The decreased levels of transcripts of cathelicidin genes in blood leucocytes of SRLV-infected goats may indicate the disturbances of homeostasis in organisms. It can be concluded that SRLV infection seems to inhibit expression of cathelicidin genes. The study was financed by a grant from the National Scientific Center No. UMO-2013/09/B/NZ/03514.

Keywords: goat, CAEV, cathelicidins, blood leukocytes, gene expression

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Authors: Sakeena Naikwadi, K. Jagaluraiah Sannapapamma

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Vetiveria zizanioides is an aromatic grass and traditionally been used in aromatherapy and ayurvedic medicine. Vetiver root is multi-functional biopolymer and has highly aromatic, antimicrobial, UV blocking, antioxidant properties suitable for textile finishing. The vetiver root (Gulabi) powder of different concentration (2, 4, 6,8 percent) were extracted by aqueous and solvent methods subjected to bioassay for antimicrobial efficiency and GCMS spectral analysis. The organic cotton fabric was finished with vetiver root extract (8 percent) by exhaust and pad dry cure methods. The finished fabric was assessed for functional properties viz., UV protective factor, antimicrobial efficiency and aroma intensity. The results revealed that Ethanol extraction showed a greater zone of inhibition compared to aqueous extract in root powder. Among the concentrations, 8 percent root extract in ethanol showed a greater zone of inhibition against gram-positive organism S. aureus and gram-negative organism E. coli. The major compounds present in vetiver root extracts were diethyl pathalate with greater percentage (87.73 %) followed by 7- Isopropyl dimethyl carboxylic acid (4.05 %), 2-butanone 4-trimethyle cyclohexen (1.21 %), phenanthrene carboxylic acid (1.03 %), naphthalene pentanoic acid (0.99 %), 1-phenanthrene carboxylic acid and 1 cyclohexenone 2-methyl oxobuty (0.89 %). The sample finished by pad dry cure method exhibited better UV protection even after 10th wash as compared to exhaust method. Vetiver extract treated samples exhibited maximum zone of inhibition against S. aureus than the E. coli organism. The vetiver root extract treated organic cotton fabric through pad dry cure method possessed good antimicrobial activity against S. aureus and E. coli even after 20th washes compared to vetiver root extract treated by exhaust method. The olfactory analysis was carried out by 30 panels of members and opined that vetiver root extract treated fabric has very good and pleasant aroma with better tactile properties that provide cooling, soothing effect and enhances the mood of the wearer. Vetiver root extract finished organic cotton fabric possessed aroma, antimicrobial and UV properties which are aptly suitable for medical and healthcare textiles viz., wound dressing, bandage gauze, surgical cloths, baby diapers and sanitary napkins. It can be used as after finishing agent for variegated garments and made-ups and can be replaced with commercial after finishing agents.

Keywords: antimicrobial, olfactory analysis, UV protection factor, vetiver root extract

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Authors: A. Díaz-Roa, P. I. Silva Junior, F. J. Bello

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Sarconesiopsis magellanica (Diptera: Calliphoridae) is a medically important necrophagous fly which is used for establishing the post-mortem interval. Dipterous maggots release diverse proteins and peptides contained in larval excretion and secretion (ES) products playing a key role in digestion. The most important mechanism for combating infection using larval therapy depends on larval ES. These larvae are protected against infection by a diverse spectrum of antimicrobial peptides (AMPs), one already known like lucifensin. Special interest in these peptides has also been aroused regarding understanding their role in wound healing since they degrade necrotic tissue and kill different bacteria during larval therapy. The action of larvae on wounds occurs through 3 mechanisms of action: removal of necrotic tissue, stimulation of granulation tissue, and antibacterial action of larval ES. Some components of the ES include calcium, urea, allantoin ammonium bicarbonate and reducing the viability of Gram positive and Gram negative bacteria. The Lucilia sericata fly larvae have been the most used, however, we need to evaluate new species that could potentially be similar or more effective than fly above. This study was thus aimed at identifying and characterizing S. magellanica AMPs contained in ES products for the first time and compared them with the common fly used L. sericata. These products were obtained from third-instar larvae taken from a previously established colony. For the first analysis, ES fractions were separate by Sep-Pak C18 disposable columns (first step). The material obtained was fractionated by RP-HPLC by using Júpiter C18 semi-preparative column. The products were then lyophilized and their antimicrobial activity was characterized by incubation with different bacterial strains. The first chromatographic analysis of ES from L. sericata gives 6 fractions with antimicrobial activity against Gram-positive bacteria Micrococus luteus, and 3 fractions with activity against Gram-negative bacteria Pseudomonae aeruginosa while the one from S. magellanica gaves 1 fraction against M. luteus and 4 against P. aeruginosa. Maybe one of these fractions could correspond to the peptide already known from L. sericata. These results show the first work for supporting further experiments aimed at validating S. magellanica use in larval therapy. We still need to search if we find some new molecules, by making mass spectrometry and ‘de novo sequencing’. Further studies are necessary to identify and characterize them to better understand their functioning.

Keywords: antimicrobial peptides, larval therapy, Lucilia sericata, Sarconesiopsis magellanica

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Authors: O. Antypenko, I. Vasilieva, S. Kovalenko

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Investigations for new effective and less toxic antimicrobials agents are always up-to-date. The tetrazole derivatives are quite interesting objects as for synthesis as well as for pharmacological screening. Thus, some derivatives of tetrazole demonstrated antimicrobial activity, namely 5-phenyl-tetrazolo[1,5-c]quinazoline was effective one against Staphylococcus aureus and Esherichia faecalis (MIC = 250 mg/L). Besides, investigation of the 9-bromo(chloro)-5-morpholin(piperidine)-4-yl-tetrazolo[1,5-c]quinazoline’s antimicrobial activity against Esherichia coli and Enterococcus faecalis, Pseudomonas aeruginosa and Staphylococcus aureus revealed that sensitivity of Gram-positive bacteria to the compounds was higher than that of Gram-negative bacteria. So, our previously synthesized, 31 derivatives of 1-(2-(1H-tetrazol-5-yl)-R1-phenyl)-3-R2-phenyl(ethyl)ureas were decided to test for their in vitro antibacterial activity against Gram-positive bacteria (Staphylococcus aureus ATCC 25923, Enterobacter aerogenes, Enterococcus faecalis ATCC 29212), Gram-negative bacteria (Pseudomonas aeruginosa ATCC 9027, Escherichia coli ATCC 25922, Klebsiella pneumoniae 68) and antifungal properties against Candida albicans ATCC 885653. Agar-diffusion method was used for determination of the preliminary activity compared to well-known reference antimicrobials. All the compounds were dissolved in DMSO at a concentration of 100 μg/disk, using inhibition zone diameter (IZD, mm) as a measure for the antimicrobial activity. The most active turned to be 3 structures, that inhibited several bacterial strains: 1-ethyl-3-(5-fluoro-2-(1H-tetrazol-5-yl)phenyl)urea (1), 1-(4-bromo-2-(1H-tetrazol-5-yl)-phenyl)-3-(4-(trifluoromethyl)phenyl)urea (2) and 1-(4-chloro-2-(1H-tetrazol-5-yl)phenyl)-3-(3-(trifluoromethyl)phenyl)urea (3). IZM (mm) was 40 (Escherichia coli), 25 (Klebsiella pneumonia) for compound 1; 12 (Pseudomonas aeruginosa), 15 (Staphylococcus aureus), 10 (Enterococcus faecalis) for compound 2; 25 (Staphylococcus aureus), 15 (Enterococcus faecalis) for compound 3. The most sensitive to the activity of the substances were Gram-negative bacteria Pseudomonas aeruginosa. While none of compound effected on Candida albicans. Speaking about, reference drugs: Amikacin (30 µg/disk) showed 27 and Ceftazide (30 µg/disk) 25 against Pseudomonas aeruginosa. That is, unfortunately, higher than studied 1-(2-(1H-tetrazol-5-yl)-R1-phenyl)-3-R2-phenyl(ethyl)ureas. Obtained results will be used for further purposeful optimization of the leading compounds in the more effective antimicrobials because of the ever-mounting problem of microorganism’s resistance.

Keywords: antimicrobial, antifungal, compounds, 1-(2-(1H-tetrazol-5-yl)-R1-phenyl)-3-R2-phenyl(ethyl)ureas

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Authors: Philip Vercoe, Ali Hardan

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Samples of 29 Australian wild natives and exotic plants were tested in vitro batch rumen culture system for their methanogenic characteristics and potential usage as feed or antimicrobial to enhance sustainable livestock ruminant production system. The plants were tested for their in vitro rumen fermentation end products properties which include: methane production, total gas pressure, concentrations of total volatile fatty acids, ammonia, and acetate to propionate ratio. All of the plants were produced less methane than the positive control (i.e., oaten chaff) in vitro. Nearly 50 % of plants inhibiting methane by over 50% in comparison to the control. Eremophila granitica had the strongest inhibitory effect about 92 % on methane production comparing with oaten chaff. The exotic weed Arctotheca calendula (Capeweed) had the highest concentration of volatile fatty acids production as well as the highest in total gas pressure among all plants and the control. Some of the acacia species have the lowest production of total gas pressure. The majority of the plants produced more ammonia than the oaten chaff control. The plant species that produced the most ammonia was Codonocarpus cotinifolius, producing over 3 times as much methane as oaten chaff control while the lowest was Eremophila galeata. There was strong positive correlation between methane production and total gas production as well as between total gas production and the concentration of VFA produced with R² = 0.74, R² = 0.84, respectively. While there was weak positive correlation between methane production and the acetate to propionate ratio as well as between the concentration of VFA produced and methane production with R² = 0.41, R² = 0.52, respectively.

Keywords: in vitro Rumen Fermentation, methane, wild Australian native plants, forages

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