The PCR primers for O, H, and Vi antigen genes, tyv (rfbE), prt (rfbS), fliC-d, fliC-a, and viaB, were designed and used for the rapid identification of Salmonella enterica serovars Typhi and Paratyphi A with multiplex PCR. The results showed that all the clinical isolates examined of Salmonella serovars Typhi and Paratyphi A were accurately identified by this assay.Enteric fever remains an important public health problem in many countries of the world. Typhoid fever and paratyphoid fever are still serious public health problems in many geographic areas and are endemic in most countries, especially those of Southeast Asia and Africa. Recently, multiple-drugor fluoroquinolone-resistant strains of Salmonella enterica serovars Typhi and Paratyphi A have been emerging on the Indian subcontinent, spreading to, and becoming major problems, throughout the world (1, 4, 6). Typhoid fever and paratyphoid fever are sometimes-fatal infections of adults and children that cause bacteremia and inflammatory destruction of the intestine and other organs and that require urgent treatment by the administration of appropriate antibiotics. The diagnosis of typhoid fever or paratyphoid fever is made by ordinary culture methods and biochemical tests. The classic diagnosis method for typhoid fever or paratyphoid fever requires at least 4 or 5 days for positive results. A rapid, alternative method is needed for the diagnosis of typhoid fever or paratyphoid fever. Some researchers have already reported serovar Typhi detection methods with PCR that use the fliC-d gene (7), the Vi capsular antigen gene (3), and the 16S rRNA gene (9). As only one gene was targeted for the identification of serovar Typhi in these methods, strains of Salmonella serovars other than serovar Typhi were detected in some cases. In this study, we developed a more specific diagnosis method for both typhoid fever and paratyphoid fever based on a multiplex PCR technique that detected the Vi antigen gene (viaB), H antigen genes (fliC-d and fliC-a), and O antigen synthesis genes (tyv and prt). This system enabled us to identify and differentiate serovars Typhi and Paratyphi A, which are clinically important human pathogens, by only a single PCR, when we isolated the bacteria from blood or stool cultures from clinical patients.The bacterial strains used in this study were collected from the regional public health office in Japan, and all isolates were identified by biochemical and serological tests. A suspension of bacteria was heated at 100°C for 10 min. The samples were then used for the PCRs. We designed the primers tyv-s and tyv-as for detection of the tyvelose epimerase gene (tyv, previously called rfbE) and the primers fliCcom-s and fliCd-as for detection of the fliC-d gene (phase-1 flagellin gene for d antigen [H:d]) of Salmonella serovar Typhi. The primers parat-s and parat-as were designed for detection of a paratose synthase gene (prt, previously called rfbS), and the primers fliCcom-s and fliCa-as were designed for detection of a fliC-a gene (phase-1 flagellin...

EHEC O157:H7 clade 6 strains harboring stx2a and/or stx2c and clade 8 strains harboring stx2a or stx2a/stx2c were frequently associated with childhood HUS cases in Japan. Rapid and specific detection of such lineages are required for infection control measures.

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We developed a quick genetic approach to screen variants of the intimin gene (eae) by using a heteroduplex mobility assay (HMA) that targets the 5 conserved region of eae. The eae variants were categorized into 4 major HMA types and 10 minor subtypes.Enteropathogenic Escherichia coli (EPEC) and Shiga toxinproducing E. coli (STEC) produce characteristic attaching and effacing lesions using intimin encoded by eae (24). The eae genes of several strains have been cloned and sequenced and have a highly conserved 5Ј-terminal region but are variable in the 3Ј-terminal region (13). Allele-specific PCRs targeting eae genes in the variable 3Ј region have been employed to determine eae types (1,5,10,27,30,31,33) and subtypes in combination with restriction fragment length polymorphism (RFLP) (4, 27). Ramachandran et al. (29) designed universal PCR primers to amplify the Int280-encoding region and identified types by RFLP. Recently, methods using real-time PCR (25) and oligonucleotide microarray (14) have been developed. Eighteen types and nine subtypes of intimin, namely, ␣, ␣2, ␤1 to -3, ␥1, ␥2, ␦, ε, ε2 to

Strains of the multidrug-resistant (MDR) Salmonella enterica serovar Typhimurium isolated in Japan were examined for high-level fluoroquinolone resistance. Since the first isolation in 2000 (described in reference 13), we have identified 12 human and 5 nonhuman isolates with high-level fluoroquinolone-resistance (ciprofloxacin MIC of 24 g/ml or more). Most of these isolates shared some features including definitive phage type (DT12/193), resistance type (ACSSuTNCp; resistant to ampicillin, chloramphenicol, streptomycin, sulfonamides, tetracycline, nalidixic acid, and ciprofloxacin), and genotype on pulsed-field gel electrophoresis that were different from those of the MDR S. enterica Typhimurium DT104. Mutations in quinolone resistancedetermining regions of gyrA and parC were also conserved in almost all of the isolates despite the absence of any apparent epidemiological relationships among cases. This suggests that a specific clonal group of the serovar Typhimurium with high levels of fluoroquinolone resistance is disseminating among animals and humans in Japan.