Occurrence of Escherichia coli, Salmonella spp. and Staphylococcus aureus and Antimicrobial Susceptibility Profile in Locally and Commercially Produced Yogurt Sold in Addis Ababa, Ethiopia

Abstract

The present study was conducted to assess the occurrence and antimicrobial susceptibility profile of Escherichia coli and Salmonellaspp.and Staphylococcus aureus isolates from locally and commercially produced yogurt sold in Addis Ababa, Ethiopia. A total of 40 yogurt samples (20 commercially and 20 locally produced) were collected from retail markets. Samples were cultured according to standard microbiology techniques, and the Vitek 2XL compact systems (bioMérieux) were used both to confirm the presumptive colonies and antimicrobial sensitivity testing following the manufacturer’s instructions. E. coli and Salmonellaspp.were found to be 9 (45%) and 2 (10%) and 5 (25%) and 1 (5%) of locally and commercially produced yogurt samples, respectively. However, S. aureus was not detected in any of the yogurt samples. Interestingly, 7–28% of E. coli isolates were resistant to ampicillin, amoxicillin, cephalexin, cefalotin, cefpodoxime, enrofloxacin, marbofloxacin, pardofloxacin, doxycycline, tetracycline, nitrofurantoin, chloramphenicol and cotrimoxazole (thrimethoprim-sulfamethoxazole). Similarly, Salmonellaspp.isolates were resistant to ampicillin, pardofloxacin, doxycycline, and tetracycline. Our findings indicate that. E. coli and Salmonellaspp.isolates with a high percentage of antimicrobial resistance highlight the health risk for consumers. Therefore, yogurt producers and handlers need to place more emphasis on quality assurance.