Assessment of Milk Contamination, Associated Risk Factors, and Drug Sensitivity Patterns among Isolated Bacteria from Raw Milk of Borena Zone, Ethiopia

Abstract

Background. The contamination of raw milk depends on the number and type of organisms that can cause health risks, which can be judged by the presence of microorganisms and bacterial pathogens. This study evaluated bacterial contamination, the risk factor, and drug sensitivity patterns. Methods. A cross-sectional study was carried out on conveniently selected 95 milk producers. Data were collected using the structured pretest questionnaire and the observation control list. Subsequently, 15 to 20 ml of milk samples were taken for laboratory analysis. The milk samples have been diluted and continuously inoculated on the number of standard plates and the blue Eosin methylene germs for the total number of bacteria and coliforms counted. Biochemical and drug sensitivity tests have been done. The version 21 Statistical Package for the Social Sciences was used for analysis. Analysis of the associated factors using binary logistical regression analysis and a P value less than 0.05 was considered to be statistically significant. Results. The total bacteria (TBC) and coliform count (CC) average with the standard deviation were 7.57 ± 0.83 log10 and 6.54 ± 1.53 log10 CFU/mL, respectively. The prevalence of raw milk contaminated with TBC and TCC was 84 (88.4%) and 75 (78.9%), respectively. Lack of handwash practice before milking (AOR = 2.4 [95% CI: 0.35–16.4]) and using unclean milk containers (AOR = 7.47 [95% CI: 0.0023–28.64]) were found to be significantly associated with bacterial contamination of raw milk. The bacteria isolated were E. coli (30.7%), Staphylococcus aureus (16.7%), and Salmonella spp. (1.2%). Among isolated bacteria, 76.3% were extensive drug resistant, 13.2% were multidrug resistant, and 2.6% were resistant to all drugs tested in the current study. Conclusion. Guaranteed appropriate hygiene exercise during time of milking and clean containers reduced milk contamination. Doctors should consider resistance to drugs during the treatment of patients with milk disease.