Eighteen Pseudomonas aeruginosa strains of various pyocine types according to the Gillies-Govan method were selected from 126 isolates in Nagasaki area, using human blood as substitute for horse blood in the medium for typing. Standard strains of Types 1 and 16 supplied directly from Dr. R. R. Gillies were added to the mentioned 18 strains and used for the most part of this study. Indicator strains used for typing were also those presented as subcultures from him. First, the activity of pyocine produced by cultivating the test-strains at 32°C for 14 hours on Tryptosoy Agar (Eiken) plates containing horse, bovine, human or rabbit blood were studied in parallel and the results obtained were compared each other as for blood kinds. Thirteen out of 20 strains showed the same growth-inhibition patterns on the different media, and, as shown in Table 1 tabulating the results of remaining 7 strains including the standard strain Type 16, there was no difference between the media with horse and bovine blood respectively in every strain. Accordingly, bovine blood was used in further typing in place of horse blood used in the original method. The reproducibility of typing results of the 20 strains was discussed on the strength of growth-inhibition patterns shown in Table 2 which had been obtained by the tests repeated 6 times together with the last experiment. In 8 out of 20 strains the results were judged reproducible enough, but in 5 not so; and the remaining 7 strains were considered to correspond to “variable type” reported by Zabransky and Day. In conclusion, what is necessary in determination of pyocine type in wild strains is to repeat the typingtwice or more. Growth-inhibition patterns of 8 wild and 2 standard strains under various cultural conditions combining temperatures for cultivation (27°, 32° and 37°C) and incubation periods (14 and 24 hours) werefairly complicated (Table 3). It can safely be said that, from the respect of reproducibility, incubation of plates at 32°C for 14 hours is fitting for the pyocine typing, as adopted already by Gillies and Govan. “Self digestion” of pyocine once produced appears negligible, when the typing is carried out under these conditions at higher temperatures or/and longer period. Following results were obtained from the first typing of 143 isolates including 18 strains mentioned above, using bovine blood and by incubation at 32°C for 14 hours: 47 strains of Type 1, 24 Type 10, 18 Type 3, 7 Type 6, 5 Type 33, 4 Type 29, 3 Type 35, each two Types 5, 11 and 22, each one Types 4, 9, 16 and 20, 7 of non-producer, 8 of Type 1/10, and 10 unclassifiable strains (Table 4).
Recently, salmonella infection has become recognized as an important public health problem in Japan. Patients with dysentery-like symptoms without shigellae are apparently increasing in number, and thereby causatives are frequently salmonellae. In order to get epidemiological details on salmonella contamination in Osaka prefecture, we performed isolations of salmonellae from human feces as well as non-human materials including various kind of meat (beef, pork, chicken and minced meat), water of sewages and other materials. Isolated salmonellae were examined for serotypes and drugresistance. The results were summarized as follows: 1) The isolation rate of salmonellae from human feces had steadily increased during the period be-tmeen 1966 and 1970, the percentage being from 0.09 to 0.84. 2) The high incidence was seen in the case of meat and other non-human materials. We have found, incidentally, that for the isolation plate from meat generally available in the city market, MLCB plate is superior to SS plate and in the case of using Hajna's tetrathionate broth, better results were obtainable in 48 hours incubation than 24 hours incubation. 3) Out of isolated strains, 79.8% were found to be resistant (25.0mcg/ml or over) to either one of streptomycin (SM), chloramphenicol (CP) or Tetracycline (TC). Particularly, 70.6% were resistant to SM. The isolation rate of resistant strains to CP or TC was higher in non-human materials (3.4% to CP and 35.0% to TC) than in human materials (0.9% to CP and 11.0% to TC). 4) As for the resistance pattern to antibiotics, we found that two peaks were seen at the concentration 25.0mcg/ml and 100mcg/ml in the distribution of resistance valud of the strains to SM except S. enteritidis which showed only one peak at 1.56mcg/ml and any strains of which never exceeded the level 25.0mcg/ml. As a further study we investigated 20 more strains of S. enteritidis including those spared from Osaka Municipal Momoyama Hospital by the courtesy of Dr Sugiyama and those from meat and other materials isolated by us in 1971. The results were the same. To CP and TC, only one peak was demonstrated at 6.25 mcg/ml and 3.125 mcg/ml, respectively. 5) It was experienced in this series that two different phage types of S. paratyphi B (Beccles 3a and 3a Ivar. 4) were isolated from the same carrier, but the resistant pattern of them proved the same.