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Biomedical subjects

R Sakazaki

Publications and source records attributed to R Sakazaki.

At least 55 records · Page 3Linked to original sources

Peritrichous flagella in mesophilic strains of Aeromonas.

A total of 186 mesophilic strains of Aeromonas, comprising 151 A. hydrophila and 35 A. caviae, were tested for peritrichous flagella by Leifson's staining method. When incubated on solid medium for 18 hr at 22 C, peritrichous flagella were demonstrated in 28 (18.5%) of the 151 strains of A. hydrophila and in 6 (17.1%) of the 35 strains of A. caviae. The peritrichous flagella in these 34 mesophilic strains of Aeromonas were also observed by electron microscopy.

Aeromonas↗

Increased frequency of isolation of Pasteurella and Actinobacillus species and related organisms.

Ninety-six clinical isolates of Pasteurella, Actinobacillus and related organisms were submitted to our reference laboratory for identification. The procedures for detecting the 11 identified species, Pasteurella multocida, Pasteurella haemolytica, Pasteurella ureae, Pasteurella pneumotropica, Actinobacillus lignieresii, Actinobacillus equuli, Actinobacillus actinomycetemcomitans, Haemophilus aphrophilus, Cardiobacterium hominis, and two unnamed species of CDC groups, HB-5 and EF-4, are described and their clinical importance is discussed. These organisms have been increasingly isolated in Japan and are most often associated with respiratory infections and endocarditis.

Actinobacillus↗

Ecology of non-O 1 Vibrio cholerae in Toyama Prefecture.

The ecology of non-O 1 Vibrio cholerae and Vibrio mimicus as causes of cholera-like diarrhea or seafood-associated gastroenteritis has been investigated in Toyama Prefecture since 1980. The relationship between biological or serological characteristics of the isolates and their enteropathogenicity is discussed. Overall isolation rates from river water, sea water, and fish were 24.0, 59.5, and 33.7%, respectively, the isolation frequency being, in general, extremely high in the summer season, although the organisms were detected all year around in the case of sea water. Most isolates from river water were unable to grow on plates of TCBS agar to which colistin was added at a concentration of 1 microgram/ml (CL-TCBS). These strains quickly fermented cellobiose. O-51 and O-70 were the two most frequently detected serogroups among them and they did not show enteropathogenicity in the rabbit ileal loop ( RIL ) test. On the other hand, almost all isolates from sea water and fish as well as those from human diarrhea cases were able to grow on CL-TCBS, but were unable to ferment cellobiose quickly. O-36, O-10, O-6, O-8, O-39, and O-26 were the dominant serogroups of these isolates, and some of them showed enteropathogenicity in the RIL test. Six out of 98 isolates from river water, 14 out of 116 from sea water, and 19 out of 112 from fish were classified as Vibrio mimicus . All of these strains were able to grow on CL-TCBS and quickly fermented mannose but not cellobiose. O-41 was the most common serogroup among them and some of these strains showed enteropathogenicity in the RIL test. Production of a cholera-like enterotoxin among the isolates in Toyama Prefecture, if any, seemed to be poor.

Animals↗

Yokenella regensburgei gen. nov., sp. nov.: a new genus and species in the family Enterobacteriaceae.

The name Yokenella gen. nov. is proposed for a group of organisms in the family Enterobacteriaceae isolated from clinical sources and insects. Yokenella is a gram-negative, oxidase-negative, fermentative, motile rod possessing the characteristics of the family Enterobacteriaceae and the guanine plus cytosine contents of the DNA range from 58.0 to 59.3 mol%. Biochemical characteristics of this group and DNA hybridization studies indicate that the 11 strains studied here comprise a separate species which should be best placed in a new genus. This single DNA hybridization group is named Yokenella regensburgei sp. nov. The type strain of Y. regensburgei is NIH 725-83 (JCM 2403).

Animals↗

Production of cholera-like enterotoxin by Aeromonas hydrophila.

A total of 249 strains of mesophilic Aeromonas including 179 A. hydrophila and 70 A. caviae were tested for production of cholera-like enterotoxin by reversed passive latex agglutination (RPLA) assay. A cholera-like enterotoxin neutralized with cholera antitoxin was demonstrated in the culture filtrates from eight (4.5%) of the 179 A. hydrophila strains, while none of A. caviae strains revealed the enterotoxin production in the test. Production of the cholera-like enterotoxin in the eight strains of A. hydrophila was also confirmed by enzyme-linked immunosorbent assay (ELISA).

Aeromonas↗

Serological studies on Vibrio fluvialis.

The serology of 138 strains of Vibrio fluvialis was studied. Eighteen O-antigenic groups were defined among them and it was shown that the H antigens of all the strains were identical regardless of the biovar. The presence of mucoid antigen, which inhibits O agglutination, was found in some strains. As all O antisera for V. fluvialis contained some R antibody, all diagnostic O sera must be absorbed with R organisms before use. Some O antigens of V. fluvialis were identical with those of certain Vibrio cholerae serovars.

Africa↗