Microbact? 24E system identification and antimicrobial sensitivity pattern of bacterial flora from raw milk of apparently healthy lactating cows in Gwagwalada, Nigeria

摘要

Objective: To determine the prevalence of bacterial organisms from raw milk of cows in Gwagwalada and determine their susceptibility to commonly used antimicrobial agents. Methods: A total of 120 samples of milk were obtained from lactating cows that were at different stages of postpartum from six different locations in Gwagwalada metropolis. Samples were subjected to Microbact? 24E system identification, isolation and characterization of isolates, and antibiotics susceptibility test. Results: The most prevalent organisms were Staphylococcus aureus (34.1%), Escherichia coli (27.3%) and Bacillus species (18.2%) while the least isolated were Salmonella species (11.4%) and Pseudomonas aeruginosa (9.0%). The highest resistance patterns were shown by Staphylococcus aureus which displayed resistance to five drugs: amoxicillin, ampiclox, levofloxacin, norfloxacin, chloramphenicol and streptomycin. The least resistance was displayed by Bacillus species which were resistant to only two drugs, norfloxacin and chloramphenicol. Pseudomonas aeroginosa dissipated the highest pattern susceptibility to ciprofloxacin, norfloxacin, gentamicin and streptomycin while Salmonella species showed the lowest pattern of susceptibility to ciprofloxacin only. Other microorganisms dissipated susceptibility patterns ranging from 16.6%–100.0%. Conclusions: This study documented the occurrence of bacterial flora in raw milk of apparently healthy lactating cows in the Gwagwalada area. The variation in patterns of multidrug resistance and susceptibilities in our studies may lead to possibility of transfer of antibiotic resistance from raw milk consumers. More studies are required using higher molecular techniques to expose different species of microorganisms causing milk borne illness and their antibiotic resistant genes.