Biomedical subjects

A T Okatani

Publications and source records attributed to A T Okatani.

5 recordsLinked to original sources

PubMed2005

Differences in heat resistance among pathogenic Yersinia enterocolitica depended on growth temperature and serotype.

To gain a better understanding about the effect of growth temperature on heat resistance of Yersinia enterocolitica, we determined decimal reduction times at 60 degrees C (D60-values) for O:3; O:5,27; O:8; and O:9 strains harboring virulence plasmid coding for Yersinia outer membrane protein and experimentally virulence plasmid-deleted strains after they were grown to stationary phase at 7, 25, or 37 degrees C. Bacteria were inoculated into Trypticase soy broth and were incubated at several temperatures. D60-values of O:3; O:5,27; and O:8 strains were larger when they were grown at 37 degrees C than at 7 or 25 degrees C, despite the presence or absence of virulence plasmids. However, similar D60-values were observed in O:9 strains, despite growth at 7, 25, or 37 degrees C. The results indicate two types of Y. enterocolitica strains, growth temperature-dependent and -independent, and a Yersinia outer membrane protein that is not directly involved in growth temperature-dependent heat resistance.

Bacterial Outer Membrane Proteins↗

PubMed2001

Pulsed-field gel electrophoresis in differentiation of erysipelothrix species strains.

We report here the first analysis of Erysipelothrix spp. using pulsed-field gel electrophoresis (PFGE). Seventy strains of Erysipelothrix spp. were analyzed. SmaI, AscI, and NotI were tested for the ability to cleave the DNA extracted from those strains, and among them, SmaI was the most reliable enzyme. Sixty-three distinct PFGE patterns were produced, and no DNA degradation was observed, allowing the identification of all of the strains. Based on these results and on those of a previous analysis using randomly amplified polymorphic DNA and ribotyping, PFGE with SmaI might be considered to be more sensitive than those methods and to be the best method for epidemiological studies of strains of this genus.

Animals↗

PubMed2000

Randomly amplified polymorphic DNA analysis of Erysipelothrix spp.

The usefulness of randomly amplified polymorphic DNA method (RAPD) to identify each species of genus Erysipelothrix and for epidemiological analysis of this genus was studied. Eighty-one strains and 18 random primers were tested. Among the tested primers, the primers NK51 (GGTGGTGGTATC) and NK6 (CCCGCGCCCC) produced noticeable results. The primer NK51 revealed four species-specific RAPD patterns. Of the 66 strains of E. rhusiopathiae, 64 had the same unique band of 884 bp. Of the 12 strains of E. tonsillarum, 11 produced a 1,265-bp band. In addition, two strains, previously thought to be E. rhusiopathiae, produced the 1,265-bp band, suggesting that they had been misclassified. One strain of E. tonsillarum produced the 884-bp band, suggesting that it too was E. rhusiopathiae. The E. rhusiopathiae strain of serovar 13 produced a 650-bp band, and the strain of serovar 18 produced a clear 420-bp band as well as three weak bands of 1,265, 918, and 444 bp. The primer NK6 revealed 14 RAPD patterns that were not serovar specific. However, different patterns were produced among strains of the same serovar showing that the RAPD method is able to identify the genetic variations of strains of this genus and can rapidly and easily differentiate strains of the same serovar. Based on these results, we concluded that the RAPD method with primers NK51 and NK6 is a rapid and reliable method to identify the species of this genus; we also concluded that this method might be a useful tool for the epidemiological analysis of the Erysipelothrix species.

Erysipelothrix↗

PubMed1999

Prevalence and persistence of Salmonella in broiler chicken flocks.

Cecal contents of 2,345 broiler chickens consisting of 28 flocks originated from 12 farms were examined for the prevalence of Salmonella to know the actual status of infection with Salmonella in the chicken flocks. Salmonella was isolated from 336 (14.3%) samples. From these isolates, eight serovars were identified. Of the 336 Salmonella isolates, 242 (72.0%) were serotyped as S. Blockley, 60 (17.9%) S. Hadar, 15 (4.5%) S. Bredeney, nine (2.7%) S. Schwarzengrund, four (1.2%) S. Anatum, three (0.9%) S. Enteritidis, two (0.6%) S. Ohio, and one (0.3%) S. Livingstone. The same serovars of Salmonella were repeatedly found in the chickens from the same farms. S. Typhimurium and S. Enteritidis were detected in pooled broken eggshell samples collected from the hatchery. Analysis of plasmid profiles revealed 11 patterns of S. Blockley and seven patterns of S. Hadar. Strains of the same plasmid profiles of S. Blockley were isolated repeatedly from the same farm over one year after the first isolation.

Animals↗

PubMedDate not supplied

Contamination of Salmonella blockley in the environment of a poultry farm.

Cecal and environmental samples were collected and examined for the presence of Salmonella on a farm where a high prevalence of Salmonella blockley in chickens was observed. Of 895 cecal and 525 environmental samples examined, 242 (27.0%) and 202 (38.5%) samples, respectively, yielded S. blockley. From the analysis of plasmid profile patterns, 11 different plasmid profile patterns were found among 444 isolates, with plasmid patterns c and d the most frequent among the isolates from ceca and the environment. Salmonella blockley was isolated from environmental samples such as floor litter, walls, drinking water, waste water, dust, and soil collected when barns were occupied and was positive in drinking water, waste water, and soil when samples were collected from empty barns with occupied neighboring barns, but it was negative in all environmental samples with the exception of soil when the environmental samples were collected from empty barns with empty neighboring barns.

Animal Husbandry↗