Influences of antibiotics on intestinal flora were investigated by means of semiquantitative study, especially of lactose fermenting (L+) and nonfermenting bacilli (L-) isolated from 149 patients suffering from acute infectious diseases of intestinal tract and treated with kanamycin (KM), KM combined with Tetracyclin (CKT) and other antibiotics. The results were as follows:
1. Oral administration of KM (2.0-3.0g) inhibitd L+ in 45 out of 53 cases (84.9%) and L-in 37 out of 42 cases (88.0%), disappearance of the total intestinal microflora being in 21 out of 53 cases (39.6%).
2. Oral administration of CKT (KM 12.5 mg per kg daily +TC 12.5 mg per kg daily) inhibited L+ in 17 out of 18 cases (94.4%), disappearance of the total intestinal microflora being in 7 out of 18 cases (38.9%).
3. Oral administration of Chloramphenicol (CP)(2.0-3.0 g daily) inhibited L+ in 17 out of 42 cases (40.5%), and L_ in 14 out of 26 cases (53.8%), disappearance of the total intestinal flora being in only one out of 43 cases (2.4%).
4.0ral administration of Tetracycline (TC)(2.0g daily) inhibted L+ in 20 out of 22 cases (90.9%) and L_ in 6 out of 20 cases (30.0%), disappearance of the total intestinal microflora being observed in none of the 22 cases.
5. It was found that KM was an excellent “enteric aseptic”, in comparison with CP and TC in aspects of inhibiting capacity of L+, L_ and total intestinal microflora.
6. It was found that CKT was a better “enteric aseptic” as compared with KM, because of the same effect in smaller dosis.
7. No case of staphylococcal enteritis was observed in the patients orally treated with KM or CKT.