Prevalence and Risk Factors of Mastitis and Isolation, Identification and Antibiogram of Staphylococcus Species from Mastitis Positive Zebu Cows in Toke Kutaye, Cheliya, and Dendi Districts, West Shewa Zone, Oromia, Ethiopia

Purpose: Mastitis is one of the major global problems severely affecting the dairy sector. Staphylococcus species are the primary bacteria consistently identified from mastitic milk. This study was aimed to estimate the prevalence of mastitis, isolate Staphylococcus species, determine risk factors, and the antimicrobial susceptibility profile of Staphylococcus species from mastitic Zebu cows in West Shewa Zone, Ethiopia. Materials and Methods: A total of 404 lactating Zebu cows were tested for mastitis. Isolation and identification of Staphylococcus from mastitis positive samples were done by bacteriological culture and biochemical tests. Further identification of coagulase-negative Staphylococcus (CNS) species and antimicrobial susceptibility test of the Staphylococcus aureus and the CNS was done by the Phoenix machine. Descriptive statistics was used to summarize the prevalence of mastitis while the Chi-square test and logistic regression were used to determine the association between the prevalence of mastitis and the risk factors and the magnitude of association, respectively. Results: The present study showed an overall cow and quarter level mastitis prevalence of 30.5% (95% confidence interval [CI]:26.0-35.2) and 8.3% (95% CI 7.0-9.8), respectively. The quarter level isolation rate of Staphylococcus species was 38.6% (95% CI: 30.1-47.6). Five Staphylococcus species namely S. intermedius, S. hyicus, S. aureus, S. lentus, and S. sciuri were identified. The latter two are CNS and were identified for the first time in Ethiopia. Antimicrobial susceptibility testing showed none of the isolates of S. aureus, 100% of S. sciuri, and 87.5% of S. lentus species were multidrug-resistant. The independent predictors of mastitis (p<0.05) were the age of the cows, stage of lactation, type of housing, the interval of bedding cleaning, and previous history of mastitis. Conclusion: The study showed a high prevalence of mastitis, Staphylococcus species, and multidrug resistant S. lentus, and S. sciuri in Zebu cows.

Automated summary

The study revealed a high prevalence of mastitis, multidrug-resistant Staphylococcus species, including Staphylococcus lentus and Staphylococcus sciuri which were identified for the first time in Ethiopia, in Zebu cows.