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Vibrio cholerae non-O1, non-O139 was isolated from natural surface waters from different sites sampled in diarrhea endemic zones in Kolkata, India. Twenty-one of these isolates were randomly selected and included in the characterization. The multiserogroup isolates were compared by their virulence traits with a group of clinical non-O1, non-O139 isolates from the same geographic area. Of the 21 environmental isolates, 6 and 14 strains belonged to Heiberg groups I and II, respectively. Three of the environmental isolates showed resistance to 2,2-diamine-6,7-diisopropylpteridine phosphate. All of the non-O1, non-O139 strains were positive for toxR, and except for one environmental isolate, none of them were positive for tcpA in the PCR assay. None of the isolates were positive for genes encoding cholera toxin (ctxA), heat-stable toxin (est), heat-labile toxin (elt), and Shiga toxin variants (stx) of Escherichia coli. Additionally, except for one environmental isolate (PC32), all were positive for the gene encoding El Tor hemolysin (hly). The culture supernatants of 86% (18 of 21) of the environmental isolates showed a distinct cytotoxic effect on HeLa cells, and some of these strains also produced cell-rounding factor. The lipase, protease, and cell-associated hemagglutination activities and serum resistance properties of the environmental and clinical isolates did not differ much. However, seven environmental isolates exhibited very high hemolytic activities (80 to 100%), while none of the clinical strains belonged to this group. The environmental isolates manifested three adherence patterns, namely, carpet-like, diffuse, and aggregative adherence, and the clinical isolates showed diffuse adherence on HeLa cells. Of the 11 environmental isolates tested for enteropathogenic potential, 8 (73%) induced positive fluid accumulation (>100) in a mouse model, and the reactivities of these isolates were comparable to those of clinical strains of non-O1, non-O139 and toxigenic O139 V. cholerae. Comparison of the counts of the colonized environmental and clinical strains in the mouse intestine showed that the organisms of both groups had similar colonizing efficiencies. These findings indicate the presence of potentially pathogenic V. cholerae non-O1, non-O139 strains in surface waters of the studied sites in Kolkata.Vibrio cholerae non-serogroup O1 strains are ubiquitous in aquatic environments (35) and have been recognized as the causative agents of sporadic cholera-like disease and outbreaks (5,34,39,43). In addition, environmental nontoxigenic, non-O1 strains play an important role in the evolution of toxigenic V. cholerae (19). However, only a minority of the strains of V. cholerae non-O1 seem to be enteropathogenic. The pathogenicity markers of vibrios are lacking in many species, including V. cholerae non-O1, non-O139 strains. The nature of virulence and the infective doses need to be determined for the establishment of guidelines for risk assessment of each species in surface water and food material earmarked for hu...

Members of the genus Aeromonas (family Aeromonadaceae) are medically important, Gramnegative, rod-shaped micro-organisms and are ubiquitous in aquatic environments. Aeromonas species are increasingly recognized as enteric pathogens; they possess several virulence factors associated with human disease, and represent a serious public health concern. In the present study, putative virulence traits of Aeromonas hydrophila isolates collected from different natural surface waters of Kolkata, India, were compared with a group of clinical isolates from the same geographical area using tissue culture and PCR assays. Enteropathogenic potential was investigated in the mouse model. Of the 21 environmental isolates tested, the majority showed cytotoxicity to HeLa cells (81 %), haemolysin production (71 %) and serum resistance properties (90 %), and they all exhibited multi-drug resistance. Some of the isolates induced fluid accumulation (FA ratio¢100), damage to the gut and an inflammatory reaction in the mouse intestine; these effects were comparable to those of clinical strains of A. hydrophila and toxigenic Vibrio cholerae. Interestingly, two of the isolates evoked a cell vacuolation effect in HeLa cells, and were also able to induce FA. These findings demonstrate the presence of potentially pathogenic and multi-drug-resistant A. hydrophila in the surface waters, thereby indicating a significant risk to public health. Continuous monitoring of surface waters is important to identify potential waterborne pathogens and to reduce the health risk caused by the genus Aeromonas.

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In the last three decades use of antibiotics in livestock sector has grown tremendously. The uses of these antibiotics have profound impacts on animal health, farmer income and public health. From April, 2016 to March, 2017, a hospital based retrospective study was conducted using clinical record sheet of goat patients (N=1405) at Teaching Veterinary Hospital (TVH) of Chittagong Veterinary and Animal Sciences University (CVASU), Bangladesh; to assess the groups of antimicrobials used, perception of goat owners' on antibiotics and the annual therapeutic costs for antibiotics that had been used for the treatment of goats at TVH. At TVH, the most prescribed antibiotic was streptomycin-penicillin [437 (31.10%)], whereas the least used antibiotic was tylosin [7 (0.49 %)]. From anthopo-clinical analysis, only 24% farmers said they are familiar with the term "antibiotic", but no farmer had any ideas about antimicrobial resistance and its withdrawal period. Considering the average body weight 20-30 kg of goat patients' we calculated the cost of antibiotic purchase and found the highest money (968.18-1450.04 U.S. Dollars/annum) was expenditure to purchase Gentasone plus ® (gentamicine-sulfadiazinetrimithoprime) and the lowest (5.37-8.06 USD/annum) was for tylosin. Ensuring and dissemination of proper knowledge to the farmer regarding antibiotics will prevent them from self purchase and irrational use therefore will help us to reduce the risk of antibiotic resistance in food animal.