Abstract

The indiscriminate disposal of abattoir wastewater into the environment could result in the spread of potential pathogenic microorganisms which constitute public health challenges. The aim of the study was to determine the antibiotic susceptibility profile of Salmonella spp isolated from abattoir wastewater, and screen for extracellular virulence factors. A total of 48 abattoir wastewater samples from various locations in Benin City were assessed. Standard culture-based techniques and Analytical Profile Index 20E were used to identify the isolates. Antibiotic susceptibility profile was done using the Kirby-Bauer disc diffusion method. While bacterial extracellular virulence factors were examined using the standard bacteriological and microtiter plate method. Results revealed occurrence of Salmonella species on the samples was 14(29.2%). The distribution pattern was; Government abattoir 4(25%), Victory abattoir 8(50%), and UBTH co-operative abattoir 2(12.5%). The resistance profile of the Salmonella species includes ampicillin and tetracycline 8(57.1%), azithromycin 10(71.4%) nitrofurantoin 7(50%), and chloramphenicol 6(42.9%). The Salmonella species were also sensitive to gentamicin 12(87.5%), ciprofloxacin 11(78.6%), trimethoprim-sulfamethoxazole 10(71.4%), fosfomycin 9(64.3 %) and amoxicillin-clavulanate 7(50.0%). A total of 13 species (92.9%) were resistant to a minimum of 1 antibiotic while 10(71.4%) of the isolates were resistant to a minimum of 3 antibiotics. A total of 10(71.4%) species exhibited multiple drug resistance (MDR) with a multiple antibiotic resistance index of 3.0. The virulence factor formation for Salmonella species is as follows: gelatinase production (68.9%), protease activity (65.5%), β-haemolytic activity (68.9%), and DNA degrading activity (68.9%). The recovery of Salmonella species with virulence potential which also exhibited multiple antibiotic resistance calls for concern from the appropriate authorities to ensure responsible use of antimicrobials and to monitor the appearance of antimicrobial resistance to safeguard public health.