Studies on antimicrobial resistance of salmonella from layers

Abstract

Salmonellosis is one of the diseases causing clinical and sub clinical infections in poultry, affecting the egg production. It is one of the most common and economically important food-borne zoonotic disease. In this study, a total of 900 cloacal swab samples were collected from ten commercially organised layer farms from each district of North western agro climatic zone namely Namakkal, Dharmapuri and Krishnagiri districts. Thirty samples were taken by unbiased random sampling method. The samples were screened for Salmonella after pre enrichment and enrichment of the bacteria. Fourteen antibiotics were short listed from among the most commonly used antibiotics in poultry farms from where the swabs were collected. newline By standard method of isolation of Salmonella, fourteen isolates were obtained. The isolates were designated as per the Field sampling protocol part I of Project management unit, UKRI GCRF One Health Poultry Hub of Tamil Nadu Veterinary and Animal Sciences University with slight modifications. All the isolates were confirmed as Salmonella by biochemical tests and PCR. newline Each one isolate (NF3CS2) and NF4CS3 showed amplification for qnrS, qnrD respectively. qnrB resistance genes were amplified in 6 isolates. newline sul1 gene responsible for sulphonamide resistance was amplified three of the isolates and the genes responsible for aminoglycoside resistance namely aac (3)-II and aac(6) lb-cr were amplified in 6 and 2 isolates respectively. newline The present study showed resistance pattern against streptomycin (aminoglycosides), Co-trimaxazole (sulphonamides), and Ciprofloxacin (fluroquinolones) by multiplex PCR. newline Key words: Salmonella, PCR, Multiplex PCR, Antimicrobial resistance newline newline