Type E botulinum toxin (BoNT/E)-producing Clostridium butyricum strains isolated from botulism cases or soil specimens in Italy and China were analyzed by using nucleotide sequencing of the bont/E gene, random amplified polymorphic DNA (RAPD) assay, pulsed-field gel electrophoresis (PFGE), and Southern blot hybridization for the bont/E gene. Nucleotide sequences of the bont/E genes of 11 Chinese isolates and of the Italian strain BL 6340 were determined. The nucleotide sequences of the bont/E genes of 11 C. butyricum isolates from China were identical. The deduced amino acid sequence of BoNT/E from the Chinese isolates showed 95.0 and 96.9% identity with those of BoNT/E from C. butyricum BL 6340 and Clostridium botulinum type E, respectively. The BoNT/E-producing C. butyricum strains were divided into the following three clusters based on the results of RAPD assay, PFGE profiles of genomic DNA digested with SmaI or XhoI, and Southern blot hybridization: strains associated with infant botulism in Italy, strains associated with food-borne botulism in China, and isolates from soil specimens of the Weishan lake area in China. A DNA probe for the bont/E gene hybridized with the nondigested chromosomal DNA of all toxigenic strains tested, indicating chromosomal localization of the bont/E gene in C. butyricum. The present results suggest that BoNT/E-producing C. butyricum is clonally distributed over a vast area.

Escherichia coli, which causes diarrhea in humans, can be classified into the following heterogenous groups: enterohemorrhagic E. coli (EHEC), enteropathogenic E. coli (EPEC), enteroaggregative E. coli (EAggEC), enteroinvasive E. coli (EIEC), and enterotoxigenic E. coli (ETEC). These diarrheagenic E. coli categories are differentiated on the basis of their infection and pathogenic mechanisms. Serotyping, phenotypic assays, and molecular detection assays are very useful in identifying these diarrheagenic E. coli categories (2, 12).Since several virulence factors and DNA sequences of diarrheagenic E. coli have been identified, their molecular analyses have been performed using genetic detection assays, including PCR and DNA hybridization (5, 21, 26). The PCR method, which is a rapid gene detection assay, is particularly effective in identifying these diarrheagenic E. coli categories. Several PCR methods for detecting the various virulence factors have been reported elsewhere (1,6,22).However, conducting the separate PCR reactions that are required for the detection of the virulence factors in order to assign an isolated E. coli strain to one of the five categories is very laborious and time comsuming. Therefore, various multiplex PCR methods have been developed for the simultaneous detection of several pathogenic genes in one PCR reaction (15,18,20,23). Using the multiplex PCR method, we will be able to save the time and effort involved in analyzing various virulence factors. Some multiplex PCR systems have been reported for the rapid detection of specific virulence factors that distinguish EHEC O157 from other serotypes of EHEC (10,11,14,16,17). Cebula et al. (3) reported the multiplex PCR systems for the simultaneous detection of stx1, stx2, and uidA genes, which are specific to EHEC O157:H7. Wang et al. (27) have also reported the combination of certain multiplex PCR systems for the detection of stx1, stx2, stx2 variants, eaeA, EHEC hlyA, and rfbE O157 , which are specific to the O157 serotype, and fliC H7 , which is specific to the flagellum H7 serotype. Pass et al. (15) and Toma et al. (25) reported the use of multiplex PCR systems for the detection of 11 and 6 virulence genes, respectively. However, the systems described by them for simultaneous categorization of E. coli have not been completely effective for the simultaneous categorization of all diarrheagenic E. coli. The multiplex PCR system reported Abstract: A one-shot multiplex polymerase chain reaction (PCR) was developed for detecting 12 virulence genes of diarrheagenic Escherichia coli. In order to differentiate between the five categories of diarrheagenic E. coli, we selected the target genes: stx1, stx2, and eaeA for enterohemorrhagic E. coli (EHEC); eaeA, bfpA, and EAF for enteropathogenic E. coli (EPEC); invE for enteroinvasive E. coli (EIEC); elt, estp, and esth for enterotoxigenic E. coli (ETEC); CVD432 and aggR for enteroaggregative E. coli (EAggEC); and astA distributed over the categories of diarrheagenic E. coli. In our multiplex PCR ...

To clarify the relationship between the epidemics of severe invasive group A streptococcal infections (streptococcal Toxic Shock-Like Syndrome: TSLS) and common group A streptococcal infections in Japan, we examined the T serotypes of S. pyogenes strains (group A streptococci) isolated from clinical specimens of the streptococcal infections (17999 cases) in the period 1990-5, including the severe infections (TSLS) (29 cases) in the period 1992-5. Characteristic points of the analyses were: (1) dominant serotypes of the infections in these periods were T12, T4, T1, T28 and TB3264, which were consistently isolated; (2) isolates of T3 rapidly increased through 1990 to 1994 while T6 decreased in the period 1990-3; (3) when Japanese area was divided into three parts, T3 serotype tended to spread out from the north-eastern to the south-western area; (4) strains of T3 and T1 serotypes were dominant in the TSLS. Dominant-serotype strains of streptococcal infections did not always induce severe infections and dominance of T3 serotype in the TSLS seemed to be correlated with the increase of T3 in streptococcal infections. These results may indicate that certain clones of S. pyogenes are involved in the pathogenesis of the TSLS.

T and emm types were determined for group A streptococci isolated from patients with various infections during 1990-1999 in Toyama Prefecture, Japan. Out of 906 isolates, 872 isolates were divided into 20 T serotypes, and 34 isoltes were T nontypeable (TNT). T12, T1, and T4 were dominant among 699 throat isolates; on the other hand, T11, T28, TB3264, and TNT were dominant among 80 skin isolates. The emm types of 190 isolates were determined following specific PCR amplification and sequencing of the products. Twenty T serotypes were divided into 34 T type/emm type combinations. Thirty-four TNT isolates were divided into 14 emm types, in which emm58 was the most common (38%). Among 82 throat isolates randomly selected, predominant T types T12, T1, and T4 isolates were of the respective same numbers in emm type. T11/emm89, T28/emm28, TB3264/emm13w, and TNT/emm58 were predominant among 80 skin isolates. emm-type distribution observed in the present study was that usually reported in the western world. To our knowledge, 3 T/emm is a novel combination. These results show that emm typing allows the characterization of group A streptococci from various sources.

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