Veterinary World (Dec 2018)
Phenotypic and genotypic drug resistance profile of Salmonella serovars isolated from poultry farm and processing units located in and around Mumbai city, India
Abstract
Background and Aim: The extensive use of antimicrobials in poultry has led to an increase in bacterial multidrug resistance, and the emergence of multidrug-resistant nontyphoidal Salmonella is a global problem. This study was performed to detect antibiotic-resistant Salmonella serovars in poultry farming and processing environment. Materials and Methods: A total of 956 various samples, comprising 432 farm origin, 324 poultry processing stage wise and environmental, and 154 product processing stages and environmental samples, were collected from poultry farms and processing units located in and around Mumbai city. Of a total of 71 recovered isolates, 42 randomly selected Salmonella isolates were subjected for antibiotic susceptibility testing by disk diffusion method and serotyping. A total of 31 serotypically confirmed isolates were characterized for the presence of tetA, tetB, blaTEM, and CTX-M gene. Results: Higher resistance was recorded against Doxycycline (100%), followed by Oxytetracycline (97.62%), Neomycin (88.10%), Erythromycin (83.33%), Tetracycline (78.57%), and Ceftizoxime (35.71%). Resistance from 0.00 to 26.19 percent was found to antimicrobials, namely Norfloxacin (26.19%), Ampicillin (21.43%), Azithromycin (21.43%), Ciprofloxacin (19.05%), Colistin (4.76%), Streptomycin (16.67%), Cefotaxime (14.19%), Enrofloxacin (14.29%), Amoxyclav (14.29%), Gentamicin (7.14%), Chloramphenicol (4.76%), Amikacin (4.76%), and Ceftazidime (0.0%). Results demonstrate that the Salmonella Virchow dominated and all serotypes were found to carry Tetracycline resistance gene tetA, 5 isolates were found to be positive for blaTEM, whereas none of the isolates were carrying tetB and CTX-M gene. Conclusion: This study revealed that there is a significant rise of Tetracycline resistance with the presence of tetA gene in Salmonella spp. which indicates selective pressure for adopting resistance against tetracycline group of antibiotics.
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