Antimicrobial Susceptibility Profiles of Bacteria Isolated from Traditionally Fermented Bovine Milk from Selected Farms of Kajiado- Central Sub-County, Kenya

Abstract

Introduction: Fermented bovine milk provides a conducive environment for the growth of bacteria some of which could be of zoonotic importance. These bacteria can develop antimicrobial resistance (AMR) due to the regular use of antibiotics in animals. Materials and methods: This cross-sectional study was undertaken to determine the antibiotic sensitivity of bacteria isolated from traditionally fermented milk obtained and processed from 114 indigenous cows kept by Maasai pastoralists in Kajiado County, Kenya. The Kirby-Bauer Disk diffusion method was used to determine the antimicrobial susceptibility profiles of the isolated Staphylococcus spp., Escherichia coli, Klebsiella spp., and Salmonella typhi. Results: The susceptibility of the isolated bacteria was determined using nine antibiotics namely chloramphenicol (10μg), kanamycin (30μg), penicillin G (10μg), streptomycin (10μg), oxytetracycline (30μ) tetracycline (30μg), vancomycin (30μg), gentamycin (10μg) and Ampicillin (10μg). The Staphylococcus (S.) aureus isolates exhibited diverse resistance patterns to the antibiotics with the greatest resistance observed against oxytetracycline (69.2%), streptomycin (69.2%), and kanamycin (61.5%). However, a significant proportion of the S. aureus strains demonstrated a 100% susceptibility rate to gentamycin and vancomycin. Escherichia coli isolates exhibited resistance to vancomycin (100%), tetracycline (80%), oxytetracycline (80 %), and ampicillin (60 %) and were highly (100%) sensitive to the other antibiotics. Salmonella typhi isolates were resistant to vancomycin (88.8%) and highly (100%) sensitive to chloramphenicol, penicillin G, gentamycin, and streptomycin. Klebsiella spp. were highly resistant to vancomycin (100%) and were sensitive to gentamycin (100%) and streptomycin (100%). Conclusion: The study showed a high prevalence of AMR in bacteria isolated from traditional milk consumed by the pastoralists and thus there is a high risk of zoonotic spread of the pathogenic bacteria. There is a need to educate the local households on strategies to minimize the occurrence of AMR in animals and also improve hygiene practices in the preparation of traditionally fermented milk.