Occurrence and Antimicrobial Susceptibility Profiles of Salmonella species among Chickens of some Commercial Poultry Farms in Benue State, Nigeria

Abstract

Salmonella is a facultative anaerobic Gram-negative rod, an intracellular bacterium of zoonotic importance. This study aimed at investigating the presence of Salmonella in chickens in three local government areas of Benue State. A total of 588 cloacal swabs were made randomly from 264 layers and 324 broilers at Makurdi, Otukpo and Gboko local government areas of Benue State, from March to July 2015. Salmonellae were isolated and identified using standard bacteriological techniques namely culture, Gram’s staining and biochemical methods. Cultural characteristics of isolates on the used media were observed, pink colonies with or without black centers on xylose lysine deoxycholate agar (XLD) and brilliant green agar (BGA) were considered presumptive Salmonella isolates and were later characterized biochemically using standard conventional methods. Thereafter, an in-vitro antimicrobial susceptibility testing was conducted on Salmonella isolates using the disc diffusion method with six selected, commonly used antimicrobials ampicillin (10 µg), gentamycin (30 µg), tetracycline (30 µg), chloramphenicol (30 µg), norfloxacin (10 µg) and amoxicillin (10 µg). Thirteen (13) isolates were identified and confirmed as Salmonella species, giving an overall occurrence rate of 2.21% (13/588). Isolates were found to be most susceptible to Norfloxacin and Chloramphenicol. In conclusion, this study revealed the occurrence of Salmonella in chickens within the study area, this is of great concern due to possible effect of disease dissemination in chickens, as well as transmission to humans through the food chain.