Abstract
The authors conducted studies on the PAS-resistant tubercle bacilli from the sputa of 168 in-patients, during the period of 1953 to 1955 at Kamo National Sanatorium. Results were as follows:
1) Comparing with streptomycin or isoniazid-resistance, complete resistance (over 10γ/ml) to PAS was very few. However, slight resistance to PAS (1γ/ml up to 10γ/ml) was very frequent.
2) Resistance to PAS increased with increased amounts of its administration. Resistance of over 10γ/ml was frequently recognized in cases of PAS administration between 1, 200g to 3, 600g of dosis.
3) Increase of PAS-resistance was remarkably found in the cases with large cavity or with many cavitations at x-ray examination.
4) Almost all the PAS-resistant tubercle bacilli by 10γ/ml showed simultaneously increase of resistance to streptomycin.
