Aerobic Microorganisms Isolated from Mastitic Bovine Milk and Their Antimicrobial Susceptibility Profiles, Ethiopia

摘要

This study was undertaken from October 2010 to June 2011 to isolate aerobic microorganisms from mastitic bovine milk and to determine their antimicrobial resistance profiles in and around Gondar town, north western Ethiopia. The study was conducted using clinical examination, California Mastitis Test (for screening of subclinical mastitis), microbiological examination and antimicrobial susceptibility testing. A total of 1097 milk samples collected from 290 local zebu and Holestein-zebu cross breed cows were cultured for microbial isolation. Fourteen types of bacterial and a fungal species were isolated. Staphylococcus simulans and Staphylococcus aureus were the leading causes of clinical and subclinical mastitis, respectively. Most isolates were susceptible to antimicrobial effects of chloramphenicol followed by polymyxin B whereas they were resistant to that of penicillin G and oxytetracycline. All Candida albicans isolates were resistant to all the tested antimicrobials. In conclusion, large numbers of microorganisms isolated as causes of mastitis in the study area and most of them were resistant to one or more of antimicrobials tested; therefore, integrated control measures and monitoring system was suggested.