Antimicrobial resistance profiles of <em>Salmonella</em> serovars isolated from dressed chicken meat at slaughter in Kaduna, Nigeria

Abstract

Invasive non-typhoidal salmonellosis characterized by gastroenteritis and bacteremia is endemic in sub-Sahara Africa. Most infections are foodborne with animals serving as asymptomatic carriers. We investigated Salmonella serovars and associated resistance genes in chicken meat using culture, minimum inhibitory concentrations and PCR amplification of resistance genes. Of 100 samples examined, 28 (28%) were Salmonella positive and spread across six serovars: Haifa (71.4%), Chomedey (7.1%), Saintpaul (7.1%), Kainji (7.1%), Derby (3.6%), and Blockley (3.6%). Antimicrobial resistance was observed to ciprofloxacin (85.7%), nalidixic acid (75.0%), sulfamethoxazole (67.9%), tetracycline (67.9%), trimethoprim (42.9%), gentamicin (35.7%), streptomycin (32.1%), ampicillin (10.7%), chloramphenicol (10.7%), kanamycin (7.1%) and florfenicol (3.6%). All isolates were susceptible to cefotaxime, ceftazidime and colistin, whereas 19 (67.9%) showed multidrug resistance to at least three antimicrobials. The predominant resistance type was Cip-Gen-Nal-Smx-Tet-Tmp detected in six (21%) isolates. Multidrug resistance of Salmonella serovars was high in the sampled chicken meat with resistance most observed against ciprofloxacin. This suggests possible horizontal transfer of plasmid-mediated quinolone resistance genes, which may compromise the clinical use of fluoroquinolones. Thus, improved hygiene and provision of adequate facilities at meat processing centers could help limit meat contamination and foodborne transmission of multi-resistant non-typhoidal Salmonella serovars from chickens to humans.

Keywords

• Salmonella
• resistance to antibiotic
• chicken meat
• slaughtering
• Nigeria