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In this study, eight Escherichia coli isolates were obtained from milk samples of dairy cattle suffering from clinical/subclinical mastitis. Isolates were characterized for antimicrobial resistance traits and virulence genes. Results revealed that one isolate was harbouring New Delhi metallo-beta-lactamase gene (blaNDM ). Cloning and sequencing of the PCR amplicon confirmed the identity of the gene (GenBank accession no. KC769583) having 100% homology with blaNDM-5 (GenBank accession no. JN104597.1), and this isolate was susceptible to colistin, chloramphenicol and tetracycline only. Moreover, another isolate carried extended-spectrum beta-lactamase (ESBL) gene - blaCTX-M , and all isolates possessed blaTEM gene. Of the eight isolates, only one isolate was positive for shiga toxin gene (stx2), and none were harbouring stx1 gene. Occurrence of New Delhi metallo-beta-lactamase (blaNDM ) in one E. coli isolate and ESBL genes in other isolates poses a potential threat to human health following possible entry and spread through food chain.

Harnessing, and understanding the mechanisms of growth and activity of, biofilms of electroactive bacteria (EAB) on solid electrodes is of increasing interest, for application to microbial fuel and electrolysis cells. Microbial electrochemical cell technology can be used to generate electricity, or higher value chemicals, from organic waste. The capability of biofilms of electroactive bacteria to transfer electrons to solid anodes is a key feature of this emerging technology, yet the electron transfer mechanism is not fully characterized as yet. Acetate oxidation current generated from biofilms of an EAB, Geobacter sulfurreducens, on graphite electrodes as a function of time does not correlate with film thickness. Values of film thickness, and the number and local concentration of electrically connected redox sites within Geobacter sulfurreducens biofilms as well as a charge transport diffusion co-efficient for the biofilm can be estimated from non-turnover voltammetry. The thicker biofilms, of 50 ± 9 μm, display higher charge transport diffusion co-efficient than that in thinner films, as increased film porosity of these films improves ion transport, required to maintain electro-neutrality upon electrolysis.

: Alginates are biopolymers usually obtained from brown seaweed, brown algae (Ochrophyta, Phaeophyceae), and bacteria (Azatobacter vineland and Pseudomonas species) belonging to the family of polycationic copolymers. They are biocompatible, biodegradable, non-antigenic, and non-toxic biopolymer with molecular mass ranges from 32,000-40,000 g/mol in commercial grades. These can be used as edible films or coatings in food industries and also some natural or chemical additives could be incorporated into them to modify their functional, mechanical, nutritional as well as organoleptic properties. Due to their high viscosity and extraordinary shear-thinning effect, they can be used as dietary fibers, thickening, gelling and stabilizing agents. Commercial alginates have vast applications in the fields of biomedical engineering, biotechnology, environmental contaminants treatments, food processing, and pharmaceuticals. Alginates can be used in wound dressings, bone regeneration, neovascularization, protein delivery, cell delivery, theranostic agents, oral drug delivery, controlled release systems, raft formulations, immobilization of biological agents and treatment of environmental contaminants. Various carrier systems can be formulated by the use of alginates like hydrogel, tablets, microcapsules, films, matrices, microspheres, liposomes, nanoparticles, beads, cochleate, floating and supersaturated drug delivery systems. This review presents a broad range of promising applications of alginates and it can be a great interest to scientists and industries engaged in exploring its hidden potential.

Aim:The aim of this work was to detect antibiotic resistance in Gram-negative bacteria isolated from subclinical mastitis in cattle in West Bengal.Materials and Methods:The milk samples were collected from the cattle suffering with subclinical mastitis in West Bengal. The milk samples were inoculated into the nutrient broth and incubated at 37°C. On the next day, the growth was transferred into nutrient agar and MacConkey agar. All the pure cultures obtained from nutrient agar slant were subjected to Gram-staining and standard biochemical tests. All the bacterial isolates were tested in vitro for their sensitivity to different antibiotics commonly used in veterinary practices. All Gram-negative isolates including positive control were subjected to polymerase chain reaction (PCR) for detection of blaCTX-M, blaTEM, blaSHV, blaVIM, tetA, tetB, tetC, and tetM genes considered for extended-spectrum β-lactamase (ESBL), metallo-β-lactamase, and tetracycline resistance.Results:In total, 50 Gram-negative organisms (Escherichia coli, Proteus, Pseudomonas, Klebsiella, and Enterobacter) were isolated from milk samples of subclinical mastitis infected cattle. Among these Gram-negative isolates, 48% (24/50) were found either ESBL producing or tetracycline resistant. Out of total 50 Gram-negative isolates, blaCTX-M was detected in 18 (36%) isolates, and 6 (12%) harbored blaTEM genes in PCR. None of the isolates carried blaSHV genes. Further, in this study, 5 (10%) isolates harbored tet(A) gene, and 8 (16%) isolates carried tet(B) gene. No tet(C) gene was detected from the isolates.Conclusion:This study showed emerging trend of antibiotic-resistant Gram-negative bacteria associated with subclinical mastitis in cattle in West Bengal, India.

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