ミカマイシン添加飼料で飼育された家禽におけるブドウ球菌の耐性値分布について

抄録

Staphylococcus aureus strains were isolated from each 198 and 250 chickens at 2 different farms which are geographically dispersed. All chickenes were fed with dairy products containing 0.088 mg unit mikamycin per 100 g food. Distribution pattern of mikamycin-resistance in 1, 285 strains isolated was found to be almost the same in each farm and the isolation frequency of the strains resistant to 1.6 μg/ml of mikamycin was highest.
Similarly, the isolation frequency of the resistance to mikamycin was compared in chickens fed with dairy products containing mikamycin of either usual (0.088 mg unit/100 g food) or 100-fold usual concentration. Distribution patterns of mikamycin-resistance in both groups were found to be almost the same; they are quite similar to that of control group without mikamycin. These results led us to the conclusion that the fowl fed with dairy products containing mikamycin did not excrete staphylococcal strains resistant to mikamycin as examined so far. These results were also coincident with those that the isolation of in vitro developed strains resistant to mikamycin was quite difficult.