Multivariate analyses revealed distinctive features differentiating @entity1 and XXXX isolates of Shiga toxin-producing @entity526 O157 in Japan.

@entity1 @entity23345 @entity281 @entity10952 @entity291 @entity526
Genotypes of Shiga toxin-producing @entity526 (STEC) O157 isolated from @entity1 and @entity291 were analyzed by uni- and multivariable logistic regression, and population structure methods, to gain insight into transmission and the nature of @entity1 @entity281 . Eleven genotyping assays, including PCR typing of five virulence factors ( @entity10952 ), @entity23345 ), @entity23345 ), eae, and ehxA) and a lineage-specific polymorphism assay using six markers (LSPA6), were considered in the analyses. The prevalence of the @entity10952 ), @entity23345 ), and @entity23345 ) virulence factors was significantly different between @entity1 and @entity291 isolates. However, multivariable regression revealed that the presence of only the @entity23345 ) gene was significantly associated with @entity1 isolates after controlling for confounding effects. LSPA6 typing demonstrated an apparent difference in the distribution of LSPA6 lineages between @entity1 and @entity291 isolates and a strong association between stx genotypes and LSPA6 genotypes. Population genetics tools identified three genetically distinct clusters of STEC O157. Each cluster was characterized by stx genotypes and LSPA6 genotypes. The @entity1 isolates typically comprised LSPA6 lineage I with @entity10952 ) @entity23345 ) strains and LSPA6 lineage I/II with @entity23345 ) or @entity23345 ) @entity23345 ) strains [corrected]. In contrast, the @entity291 isolates comprised LSPA6 lineage II strains withstx(2c) or @entity10952 ) @entity23345 ) strains [corrected] in addition to the clusters identified for the @entity1 isolates. Our analyses provide new evidence that the @entity23345 ) gene is the most distinctive feature in @entity1 isolates compared to @entity291 isolates in Japan, and only a subset of the genetically diverse population isolated from @entity291 is involved in @entity1 illnesses. Our results may contribute to international comparisons and risk assessments of STEC O157.
