Antibiotic resistance of bacteria isolates from raw cow milk

Abstract

Milk remains vulnerable to microbial contamination due to favorable microenvironmental conditions. The objective of this study was to assess the antimicrobial susceptibility profiles of bacterial isolates from raw cow milk obtained from four distinct bulk collection centers in Oyo, Southwest Nigeria. A total of 80 samples of raw cow milk were collected in aseptic conditions. A total of 20 samples were collected from each of the four bulk collection centers (Iseyin, Maya, Fashola, and Alaga) at different time intervals. Total viable bacteria count, isolation, and identification of bacteria, as well as antibiotic susceptibility testing by disc diffusion method, were performed. The findings revealed the presence of bacteria from five different genera, namely Staphylococcus, Enterococcus, Bacillus, Salmonella, and Escherichia in the raw cow milk samples. Antibiotic susceptibility testing demonstrated high sensitivity of the bacterial isolates to ciprofloxacin, gentamicin, and pefloxacin. This study provides additional evidence that raw cow milk serves as a conducive medium for the growth of various bacterial pathogens of medical significance. It is strongly recommended that proper aseptic techniques be implemented at the bulk collection centers to minimize the risk of bacterial contamination.

Keywords

• antibiotic susceptibility
• bacterial contamination
• milk pathogens.