Abstract
One hundred and twelve stocks of coagulase-positive staphylococcus aureus were isolated from the nasal mucous membrane of (a) hospitalized tuberculous patients, (b) nurses, (c) pupiles of middle and primary school in Onohara village where there is no hospital or infirmary, and (d) out-patients to ous hospital. Sensitivity of the stocks to antibiotic drugs and sulfonamides was studied.
The sensitivity to penicillin did not differ in the four groups. Biographically, sensitivity of staphylococci from hospitalized patients to penicillin is said to be lower than that from the out-siders because of the frequent use of antibiotic agents of the former. Our result suggest that there is a limit in the acquirement of resistance and all the four groups have almost reached this limit.
The sensitivity to streptomycin is high in group (a), (b), (c) and (d) in the increasing order, the difference being significant.
This phenomenon is similar to that in the course of resistance-acquirement to penicillin. The resistance to streptomycin will keep increasing in future as it is to penicillin.
Mechanism in the resistance-acquirement of staphylococcus to streptomycin in our hospital was investigated. Use of streptomycin for other diseases than tuberculosis was very seldom, while the number of streptomycin-resistant cocci in our hospital increased considerably in the period of 1955 and 1957.
And streptomycin-resistant cocci were found more frequently in the hospitalized tuberculous patients than in stocks from nurses. It is supposed, therefore, resistancc acquiement of staphylococci to streptomycin in our hospital is due to the use of streptomycin in tuberculous patients.
The sensitivity to tetracyclin, erythromycin and chioramphenicol did not differ in the four groups. This may be because these drugs are not widely used so that resistance to them has not developed yet.
The sensitivity to sulfisoxazol is high in group (b), (c) and (d) in the increasing order. This again is similar to the case of penicillin and the resistance will increase in future.
The sensitivity of the staphylococcus in this district was compared with stocks of Dr. Nagai of Tokyo University. There was no difference in sensitivity of these two to penicillin, chloramphenicol, tetracyclin, erythromycin and sulfonamide. However, sensitivity of staphylococci of this district to streptomycin is markedly higher than those of Dr. Nagai.
