Fifty-five Shiga toxin (Stx)-producing Escherichia coli (STEC) O26:H11 and O26:H(-) strains isolated from humans between 1965 and 1999 in Germany and the Czech Republic were investigated for their chromosomal and plasmid characteristics. All motile (n = 23) and nonmotile (n = 32) STEC O26 strains were shown to possess the identical flagellin subunit-encoding gene (fliC). We observed a striking recent shift of the stx genotype from stx(1) to stx(2) among the STEC O26 isolates. While stx(1) was the exclusive genotype identified in our collection until 1994, 94% of the isolates obtained after 1997 possessed stx(2) either alone (71%) or together with stx(1) (23%). Plasmid profiling demonstrated a remarkable heterogeneity with respect to plasmid sizes and combinations. Southern blot analysis of plasmid DNA with probes specific to potential accessory virulence genes revealed considerable additional variability in gene composition and arrangement. Pulsed-field gel electrophoresis (PFGE) differentiated 16 subgroups among the 55 STEC O26 strains. Using these techniques we demonstrate the emergence of a new clonal subgroup characterized by PFGE pattern A and a unique combination of virulence markers including stx(2) and a single, approximately 90-kb plasmid harboring the enterhemorrhagic E. coli hlyA and etp genes. The proportion of PFGE subgroup A strains among STEC O26 isolates rose from 30% in 1996 to more than 50% in 1999. Four clusters of infections with the clonal subgroup A were identified. We conclude that the STEC serogroup O26 is diverse and that pathogenic clonal subgroups can rapidly emerge during short intervals. The extensive genetic diversity of STEC O26 provides a basis for molecular subtyping of this important non-O157 STEC serogroup.

• MeSH
• bakteriální chromozomy genetika   MeSH
• bakteriální geny MeSH
• bakteriální toxiny genetika   MeSH
• enterotoxiny genetika   MeSH
• Escherichia coli klasifikace   genetika   patogenita   MeSH
• flagelin genetika   MeSH
• genotyp MeSH
• infekce vyvolané Escherichia coli epidemiologie   MeSH
• lidé MeSH
• molekulární epidemiologie MeSH
• molekulární evoluce MeSH
• molekulární sekvence - údaje MeSH
• O-antigeny * MeSH
• plazmidy genetika   MeSH
• pulzní gelová elektroforéza MeSH
• shiga toxiny MeSH
• virulence genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH
• Německo MeSH
• Názvy látek
• bakteriální toxiny MeSH
• enterotoxiny MeSH
• flagelin MeSH
• O-antigeny * MeSH
• shiga toxiny MeSH

Two sorbitol-fermenting (SF) Shiga toxin-producing Escherichia coli (STEC) O157:H- strains were isolated from patients with hemolytic-uremic syndrome in the Czech Republic in 1995. Their phenotypic and genotypic characteristics and genomic DNA fingerprints were identical or closely related to those of SF STEC O157:H- strains isolated in Germany in 1988 to 1997. This indicates that the Czech isolates belong to the SF STEC O157 clone which is widespread in Germany. It is the first finding of the clone outside Germany.

• MeSH
• bakteriální toxiny biosyntéza   MeSH
• DNA bakterií analýza   MeSH
• DNA fingerprinting MeSH
• Escherichia coli O157 klasifikace   izolace a purifikace   MeSH
• feces mikrobiologie   MeSH
• fenotyp MeSH
• fylogeneze MeSH
• genotyp MeSH
• hemolyticko-uremický syndrom mikrobiologie   MeSH
• infekce vyvolané Escherichia coli mikrobiologie   MeSH
• kojenec MeSH
• lidé MeSH
• polymerázová řetězová reakce metody   MeSH
• shiga toxin 1 MeSH
• sorbitol metabolismus   MeSH
• technika náhodné amplifikace polymorfní DNA MeSH
• Check Tag
• kojenec MeSH
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH
• Názvy látek
• bakteriální toxiny MeSH
• DNA bakterií MeSH
• shiga toxin 1 MeSH
• sorbitol MeSH