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Biomedical subjects

Jun Terajima

Publications and source records attributed to Jun Terajima.

28 records · Page 2Linked to original sources
PubMed2003

Genotypic analyses of Vibrio parahaemolyticus and development of a pandemic group-specific multiplex PCR assay.

A total of 54 Vibrio parahaemolyticus strains including pandemic O3:K6 strains and newly emerged O4:K68, O1:K25, O1:K26, and O1:K untypeable strains (collectively referred to as the "pandemic group") were examined for their pulsed-field gel electrophoresis (PFGE) and arbitrarily primed PCR (AP-PCR) profiles and for the presence or absence of genetic marker DNA sequences, toxRS/new or orf8, that had been reported elsewhere to be specific for the pandemic group. Both PFGE and AP-PCR analyses indicated that all strains of the pandemic group formed a distinct genotypic cluster, suggesting that they originated from the same clone. In addition to the pandemic group, four O3:K6 strains that did not possess the thermostable direct hemolysin (tdh) gene also belonged to this cluster and possessed the toxRS/new sequence. However, three O3:K6 strains that clearly belonged to the pandemic group by PFGE and AP-PCR did not possess the orf8 sequence. The evidence suggests that neither the toxRS/new nor the orf8 sequence is a reliable gene marker for definite identification of the pandemic group. We therefore developed a novel multiplex PCR assay specific for the pandemic group. The assay successfully distinguished pandemic group strains from other V. parahaemolyticus strains by yielding two distinct PCR products for tdh (263 bp) and the toxRS/new sequence (651 bp).

Bacterial Proteins↗
PubMed2003

Multiplex polymerase chain reaction assay for selective detection of Salmonella enterica serovar typhimurium.

A multiplex polymerase chain reaction (PCR) assay was developed for the identification of Salmonella enterica serovar Typhimurium. Three sets of primers were designed for detecting O4, H:i, and H:1,2 antigen genes from the antigen-specific genes rfbJ, fliC, and fljB, respectively. These were evaluated in a multiplex PCR assay by using DNAs from S. enterica serovar Typhimurium, 15 other Salmonella serovars, and 8 non-Salmonella enteric pathogens. Multiplex PCR proved to be capable of identifying S. enterica serovar Typhimurium specifically and differentiating it from other Salmonella serovars in addition to non-Salmonella enteric pathogens. Thus, this multiplex PCR assay can be practically applied to the identification of S. enterica serovar Typhimurium.

Polymerase Chain Reaction↗
PubMed2002

Genomic diversity of enterohemorrhagic Escherichia coli O157 revealed by whole genome PCR scanning.

Enterohemorrhagic Escherichia coli O157 is one of the leading worldwide public health concerns, causing large outbreaks of hemorrhagic colitis as well as numerous small outbreaks and sporadic cases. The variability of restriction enzyme-digestion patterns of O157 genomes, which is widely used to distinguish strains in the molecular epidemiology of O157 infections, suggests the presence of some genomic diversity among the strains. Based on the complete genome sequence of O157 Sakai, we analyzed the whole genome structures of eight O157 strains displaying diverse XbaI-digestion patterns by a systematic PCR analysis that we have named whole genome PCR scanning. This analysis identified not only the O157-specific sequences that are highly conserved among the strains, but also revealed an unexpectedly high degree of genomic diversity. In particular, prophages, including Shiga toxin-transducing phages, exhibited extensive structural and positional diversity, implying that variation of bacteriophages is a major factor in generating genomic diversity among the O157 lineage.

Chromosomes, Bacterial↗
PubMed2002

Clonal association of Staphylococcus aureus causing bullous impetigo and the emergence of new methicillin-resistant clonal groups in Kansai district in Japan.

A molecular epidemiological analysis was performed to reveal the clonal association of Staphylococcus aureus strains isolated from patients with bullous impetigo. Pulsed-field gel electrophoresis with cluster analysis, genetic and phenotypic characterizations, and antimicrobial susceptibility profiling of 88 S. aureus strains isolated from outpatients at 4 hospitals in the Kansai district in Japan were undertaken. Three distinct clonal groups were identified: 2 of them carried the exfoliative toxin (ET) A gene (eta), and the other carried the ETB gene (etb). The former groups represent 2 eta-positive clonal groups that have not been described previously. All the strains in the more dominant eta-positive clonal group and some of the strains in the etb-positive clonal group were methicillin-resistant S. aureus (MRSA) showing borderline-to-moderate resistance to beta-lactams. These MRSA strains appear to be emerging clonal groups that have not been considered in previous epidemiological studies of ET-producing S. aureus in Japan and thus pose a significant threat for future treatment of patients with bullous impetigo and/or staphylococcal scalded-skin syndrome.

Blister↗
PubMed2002

[PulseNet Japan: surveillance system for the early detection of diffuse outbreak based on the molecular epidemiological method].

As the foods are stocked below freezing and widely distributed, a kind of food-borne outbreak which occurs in separate regions or in different time, so called "diffuse outbreak", has been found at the present day. Unless the outbreak is early recognized, the number of victims would increase. Some methods have been developed to analyze the relatedness of bacteria isolated from the patients of enteric infections. PFGE, pulsed-field gel electrophoresis, is one of the methods and powerful to discriminate the difference in nucleotide sequences among bacterial genomes. Availability of PFGE analysis is appreciated to examine the linkage of each incident of food-borne infections in epidemiological investigation. A PFGE network, PulseNet Japan, is now under construction among National Institute of Infectious Diseases, local Health Institutes and Ministry of Health, Labour and Welfare.

DNA, Bacterial↗
PubMed2002

Effects of repeated subculturing and prolonged storage at room temperature of enterohemorrhagic Escherichia coli O157:H7 on pulsed-field gel electrophoresis profiles.

Three clinical strains of enterohemorrhagic Escherichia coli O157:H7 which were subcultured repeatedly or stored at room temperature over a 25-week period showed appreciable variations in their pulsed-field gel electrophoresis fragment patterns. The variations could be explained by a couple of spontaneous genetic events at most and thus did not invalidate the genetic lineage of the strains.

DNA, Bacterial↗
PubMed2002

High genomic diversity of enterohemorrhagic Escherichia coli isolates in Japan and its applicability for the detection of diffuse outbreak.

Genotyping of 1,102 enterohemorrhagic Escherichia coli isolates by the use of pulsed-field gel electrophoresis (PFGE) carried out from January to November 2000 has revealed the high genomic diversity of these isolates in Japan. By combining the results of genotyping of the isolates with the information from other epidemiological investigations of the cases, we identified a diffuse outbreak in Japan in the year 2000 that seemed to be sporadic but was actually linked. Isolates with only the Shiga toxin 2 gene derived from patient specimens and the contaminated food involved in this diffuse outbreak showed an indistinguishable PFGE profile and the same phage type. Based on the diversity of genotypes among the isolates of enterohemorrhagic E. coli O157:H7/- in Japan, we suggest the presence of a few other possible diffuse outbreaks due to the organisms, showing indistinguishable genotypes.

Disease Outbreaks↗
PubMed2002

[PulseNet Japan--network system for the utilization of epidemiological information and the results of pulsed-field gel electrophoresis].

Since 1996, we have been analyzing DNA pattern of enterohemorrhagic Escherichia coli(EHEC) O157: H7 isolates in Japan by the use of pulsed-field gel electrophoresis. The method, capable of discriminating genotypical difference of the isolates, enabled us to find the contaminated food such as salmon roe which was the causative agent for the multiprefectual outbreaks in Japan. These outbreaks which we are referring as diffuse outbreaks seem to be increasing in number, because it reflects that some of widely distributed or mass-produced food products are being contaminated by pathogens such as EHEC. In order to find a diffuse outbreak promptly and prevent it becoming large, we are constructing a network, called PulseNet Japan, for sharing the results of pulsed-field gel electrophoresis and epidemiological information among municipal public health institutes and National Institute of Infectious Diseases.

Colitis↗