Antimicrobial Susceptibility and Occurrence of Resistance genes among Salmonella arizonae isolated from Chicken Meat samples in Sokoto Metropolis, Sokoto State, Nigeria

Abstract

This study was conducted to determine the antimicrobial susceptibility and occurrence of resistance genes among Salmonella arizonae isolated from chicken meat samples collected in Sokoto metropolis, Sokoto State, Nigeria. A total of 400 chicken meat samples (breast muscle) were collected and examined for the presence of Salmonella organisms. The isolated Salmonella arizonae were then tested for antimicrobial susceptibility using the disc diffusion technique, and antimicrobial-resistant isolates were then examined for the presence of ampicillin resistance gene blaTEM, chloramphenicol resistance gene floR, and tetracycline resistance gene tetA by PCR. Salmonella aizonae were isolated in only 4.5% (18/400) of the samples examined. Antimicrobial susceptibility testing of the isolates showed susceptibility to nitrofurantoin (94.4%), nalidixic acid (94.4%), ofloxacin (77.8%), augmentin (72.2%), and cotrimoxazole (66.7%). However, the isolates were resistant to tetracycline (88.9%), ampicillin (72.2%), and chloramphenicol (66.6%). Only 8 of these isolates were resistant to one or more of the antimicrobial agents tested. Resistance gene analysis of the resistant isolates shows the presence of ampicillin resistance gene blaTEM in 75% (6/8) of the tested isolates. The presence of chloramphenicol resistance gene floR was also detected in 37.5% (3/8) of the isolates. The presence of multiple resistance genes was also detected in the isolates. A combination of two different resistance genes was detected in 62.5% (5/8) of the isolates, and the presence of all three resistance genes (blaTEM, tetA, and floR) was detected in one of the isolates. Antibiotics have been widely used in poultry to treat, prevent infections, and also in feeds to promote growth. Such practices have improved poultry performance effectively and economically but have resulted in the increase in the spread of resistant bacterial strains. In our study, a high resistance profile of 88.9% to tetracycline, a popularly used drug in the poultry industry, and the presence of multiple resistance genes in 62.5% of the isolates was also observed. There is, therefore, the need for more rational use of antibiotics in animal production and more prudent use in humans.