Sensitivity of Staphylococcus aureus Isolated From Bovine Udders to Various Chemotherapeutic Agents

유우유방원(乳牛乳房源) Staphylococcus aureus 의 각종 화학요법제(化學療法劑)에 대한 감수성시험(感受性試驗)

The minimum inhibitory concentration (MIC) of five chemotherapeutic agents (penicillin, streptomycin, tetracycline, oxytetracycline and furazolidone) was measured for 126 strains of Staphylococcus aureus isolated from the udder of dairy cattle. The results obtained were as follows: 1. The MIC of penicillin, streptomycin, tetracycline, oxytetracycline and furazolidone ranged from 0.03 to 32 ug/ml, 0.06 to 128 ug/ml, 0.06 to 128 ug/ml, 1.0 to 512 ug/ml, and 0.06 to 32 ug/ml, respectively. The most frequent MIC of the above drugs were; penicillin 0.5ug/ml, streptomycin 1.0ug/ml, tetracycline 0.5ug/ml, oxytetracycline 4.0ug/ml, and furazolidone 2.0ug/ml. 2. The number of strains resistant to penicillin. streptomycin, tetracycline and oxytetracycline were 89(70.6), 9(7.1%), 10(7.9%), and 26(20.6%), respectively. Twenty-eight (29.2%) strains showed multiple resistance to more than two antibiotics tested.