Strains of E. coli isolated from the clinically significant bacteriuria, the bile, the pus, and the feces of both outpatients and inpatients were serotyped by the use of 10 kinds of anti-0 antigen (1, 2, 4, 6, 7, 11, 17, 18, 39and75) sera. The urinary strains were groupable in 54.3 per cent, whereas the non-urinary strains, in only 20-30 per cent. 0 group 6, 75, 7, 4 and 2 occurred with disproportional frequency as a cause of the urinary tracts infections. In the distribution of the serotypes, there was a little difference between the strains from the urine of outpatients and inpatients. Among the strains from the feces, however, there was none of any specifically prominent serotypes in number. To all the serotypes afore mentioned, a small number of strains were found distributed almost evenly. It was observed that 0 group 6, and 75 were chiefly isolated from the pus and 6, 11, 2, 4, 17 were from the bile. The significance of serotyping of isolated E. coli lies in that it is essentially instrumental for the differentiation of infection's nature-whether it is reinfection or reexacerbation, and contamination or not in the consecutive screening of asymptomatic bacteriuria.
During the period from January through December in 1973, the survey centering on the detection of Salmonella and Shigella was performed on the fecal specimens of 255, 896 healthy school children and 97, 704 food handlers in Tokyo. On the course of this survey, 92 strains which were presumed as Edwardsiella tarda by preliminary tests for identification using TSI agar and LIM (Lysine-Indole-Motility) medium were isolated. Further biochemical tests of these isolates were conducted for final identification of their species. As a result, out of 92 isolates, 26 were identified as E. tarda and the remaining 66 as hydrogen sulfide (H2S)-producing Escherichia coli. Among many biochemical tests, salt tolerance test can be defined to be a very useful criterion for the differentiation between two species, for E. tarda could only grow in peptone water containing less than 3% sodium chloride, while H2S-producing E.coli, could even grow in peptone water containing 7% sodium chloride. In the light of the isolation frequency that E. tarda was obtained from only one food handler (0.001%) and 25 school children (0.01%), and H2S-producing E. coli was from 9 food handlers (0.01%) and 57 school children (0.02%), it is suggested that both H2S-producing E. coli and E. tarda are distributed more widely in children than in adults. Isolation of E. tarda and H2S-producing E. coli showed such seasonal variations that they could be isolated in a period from April through November with a peak in August, but not through December to March. Of 26 strains of E. tarda, only one was proved to be resistant against more than 100μg/m1 of SM. On, the other hand, 41 strains out of 66 H2S-producing E. coli were single or multiple resistant against antibioticsexamined.
We collected 12, 453 Shigella strains isolated in many municipal hospitals from 1965 to 1973 and surveyed their drug resistance. The results are summarized as follows. 1. Drug resistance patterns of Shigella strains are mainly restricted to resistance to TC, CM, SM and SA, and to the combinations thereof. Isolation frequency of strains resistant to KM, NA and APC is much lower than that of strains resistant to the aforementioned four drugs. 2. Isolation frequency of strains resistant to (TC.CM.SM.SA) was the highest, and followed by those resistant to SA, (CM.SM.SA), and (SM.SA). The strains with other resistance patterns were isolated rarely at less than 1%. 3. Demonstration frequency of R factors was rather low from the strains with single resistance and much higher from those with multiple resistance. The R factors were demonstrated most frequently from the triply resistant strains at a frequency of 86.7%. 4. Isolation frequency of KM-, NA-, or APC-resistant strains was rather low, but the R factors encoding resistance to KM and APC were demonstrated at high frequencies from the strains resistant to the drugs. The R factors possessing NA resistance were never isolated thus far. 5. Resistance patterns of Shigella strains and of their R factors were quite similar to those in Escherichia coli, and different from those in Salmonella, Proteus, and Pseudomonas aeruginosa.