Abstract
The drug-resistance of Shigella prevalent in Japan from 1949 to1959 was investigated, and the following results were obtained.
1. Shigella strains can easily become resistant to sulfanilamide (SA), and 90100% of Shigella flexneri lb, 2a and 2b were highly resistant to SA (resistant-type). Ninety to 80% of Shigella flexneri 3a and Shigella sonnei prevalent in Japan are still sensitive to SA (sensitive-type). Such a difference of SA-resistance between resistant and sensitive type of Shigella was not genetically investigated.
2. The annual change in the appearance of SA-resistance of Shigella prevalent in Japan is attributed to the change of type-spectrum of Shigella.
3. The antibiotics-resistance of Shigella isolated in Japan from 1953 to 1959 was investigated A single (SM or TC) resistant strain was isolated but there was no tendency that SM or TC resistant Shigella showed an increase. Single CM resistant Shigella strain has never been isolated.
4. Multiply resistant Shigella was isolated. This type of Shigella is increasing and has a major problem in both bacterial genetics and epidemiology.
5 From the epidemiological investigation of faeces of human subjects, multiply resistant E. coli and Citrobacter were isolated. The carrier of (CM. TC. SM. SA) or (CM. SM. SA) resistant E. coli was about 1.4% among 1145 healthy humans and was more in patients treated with CM, afflicted with tuberculosis aud dysentery among several kinds of in-patients.
