MaansiHussain, Sheeba2019-04-222019-04-222019-02http://krishikosh.egranth.ac.in/handle/1/5810100759The objective of this study was to determine the prevalence, virulence genes and antimicrobial resistance of non-typhoidal Salmonella isolated from commercial broiler farms. A total of 721 samples were collected from 8 commercial broiler farms, Ramnagar (n=1), Kiccha (n=1), Jawaharnagar (n=1), Shantipuri (n=1), Pantnagar (n=2) and Haldwani (n=2) representing two districts (Udham singh Nagar and Nainital) of Uttarakhand state, India. The samples (n=721) consist of poultry faeces (n=310), litter (n=127), water (n=127), feed (n=124) and manure (n=33). The overall prevalence of non-typhoidal Salmonella (NTS) was found to be 10.68% (n= 77). The highest prevalence of Salmonella was observed in water samples (19/127,14.96%) followed by poultry litter (18/127, 14.17%), poultry feed (12/124, 9.68%), poultry feces (27/310, 8.71%) and manure samples (1/33, 3.03%). According to the location, the highest prevalence was observed in Haldwani Farm 1 (27.19% ;31/144) followed by Shantipuri Farm (27.14% ,19/70), Haldwani Farm 2 (24.18%, 22/91), Pantnagar Poultry Farm-2 (3.92%, 4/102) and Pantnagar Farm-1 (0.98%, 1/102). Three different serotypes viz; Salmonella Kentucky (50.65%; 39/77), Salmonella Virchow (28.57%; 22/77) and Salmonella Typhimurium (3.89%, 3/77) were identified. Thirteen isolates (16.88%) were reported to be non typable. All 77 isolates were screened for the presence of 8 virulence genes by using PCR. The sopB gene harbored by 59 (76.62%) isolates followed by sipA 44 (57.14%), spvC 48 (62.34%), stn 47 (61.03%), mgtC 34, (44.16%), sopE1 25 (32.47%), gipA 16 (20.78%) and fliC 4 (5.19%) isolates. All 77 isolates (100%) were multidrug resistant (MDR). Among the 12 antimicrobials screened, highest resistance was observed for Erythromycin (100%, 77/77) and Nalidixic acid (100%, 77/77) followed by Tetracycline (97.40%, 75/77), Sulphafurazole (93.51%, 72/77), Cefotaxime (81.81%, 63/77), Cefazolin (80.52%, 62/77), Gatifloxacin (76.62%,59/77), Ciprofloxacin (71.43%, 55/77), Ampicillin (67.53%, 52/77), Levofloxacin (64.94%, 50/77), Cefoxitin (28.57%, 22/77) and Streptomycin (14.29%, 11/77). Pan-resistance was observed in six isolates comprising of 3 S. Kentucky, 1 S. Virchow and 2 Non typable Salmonella isolates. Fourty eight (62.34%) Salmonella isolates were identified as co-resistant to ciprofloxacin and cefotaxime. The most common resistance patterns against the 12 antimicrobials tested were observed as follows: AMP, E, LE, CIP, CTX, GAT, SF, TE, CZ, NA (17/77; 22.07%), AMP, CX, E, LE, CIP, CTX, GAT, SF, TE, CZ, NA (11/77; 14.29%), E, CTX, SF, TE, CZ, NA (6/77 ; 7.79%) and E, CTX, SF, TE, NA (6/77 ; 7.79%). All phenotypically resistant Salmonella isolates were assessed for 12 corresponding antimicrobial resistance genes. Out of 11 streptomycin resistant Salmonella isolates aadA1 and strA genes were carried by equal number of isolates, 7(63.64%) while aadA2 and strB genes were found in 8 (72.73%) and 2(18.18%) respectively. Only one isolate carried all the four tested resistant gene whereas one of the resistant isolates did not carry any of them. Sulphafurazole resistance encoding genes sul1 and sul2 were found in 25% (18/72) and 2.59% (2/72) isolates, respectively. Among the β- lactam genes, blaTEM gene was the predominant 22.22% (14/63) followed by blaCMY (1.59%, 1/63). Out of 3 tetracycline resistant genes tetA was detected in 29.33% (22/75) isolates, whereas none of the isolates carried tetB and tetG genes. Risk factors analysis revealed that the distance of manure heap from the poultry farms and the size of the flock were found to be significantly associated while size of the flock was negatively associated with the prevalence of Salmonella in the farms. Overall, our study revealed a high prevalence of multi drug resistant Salmonella in the broiler farms of the region. Co-resistant isolates (ciprofloxacin and cefotaxime) may pose a therapeutic threat and also highlights the irrational use of antimicrobials in the poultry farms in India.ennullThesis