The occurrence of antibiotic-resistant enteric bacteria in Selected Nigerian traditional dairy products

BACKGROUND: Wara and nono are popular dairy products in Nigeria, rich in nutrients, highly exposed to microbial contaminants during processing and sale and support microbial growth. OBJECTIVES: To investigate occurrence and antibiotic resistance pattern of enteric bacterial pathogens in dairy products. METHODS: Dairy products were serially diluted and cultured on Eosin Methylene Blue agar, Salmonella-Shigella agar, McConkey agar and nutrient agar at 37°C for 24 h. Characterisation and identification of isolates with API 20E kit (Biomereux, France). Antibiotic susceptibility was with agar disc diffusion. Polyvalent O and H antisera for Salmonella serotyping. RESULTS: Salmonella enterica serovar Enteritidis, Salmonella enterica serovar Typhimurium, Salmonella enterica serovar Typhi, Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter aerogenes, Enterobacter cloacae and Serratia marcescens, were identified. Dominant enteric bacterium detected was E. coli followed by Salmonella spp. Serratia marcescens was the least occurring. The isolates were most resistant to trimethoprim-sulfamethoxazole (96.7%), amoxicillin (83.3%), augmentin (83.3%), chloramphenicol (66.7%), streptomycin (50%). They were resistant to ≥ 4 (multiple) antibiotics, E. coli 8, Salmonella spp. 7, Serratia marcescens 6 and Klebsiella spp. and Enterobacter spp. 4 each. CONCLUSION: The presence of enteric bacterial pathogens in wara and nono and their resistance to multiple antibiotics was reported in this study.