Enterohemorrhagic Escherichia coli as Causes of Hemolytic Uremic Syndrome in the Czech Republic

Abstract

BackgroundEnterohemorrhagic Escherichia coli (EHEC) cause diarrhea-associated hemolytic uremic syndrome (D+ HUS) worldwide, but no systematic study of EHEC as the causative agents of HUS was performed in the Czech Republic. We analyzed stools of all patients with D+ HUS in the Czech Republic between 1998 and 2012 for evidence of EHEC infection. We determined virulence profiles, phenotypes, antimicrobial susceptibilities and phylogeny of the EHEC isolates.Methodology/Principal FindingsVirulence loci were identified using PCR, phenotypes and antimicrobial susceptibilities were determined using standard procedures, and phylogeny was assessed using multilocus sequence typing. During the 15-year period, EHEC were isolated from stools of 39 (69.4%) of 56 patients. The strains belonged to serotypes [fliC types] O157:H7/NM[fliC H7] (50% of which were sorbitol-fermenting; SF), O26:H11/NM[fliC H11], O55:NM[fliC H7], O111:NM[fliC H8], O145:H28[fliC H28], O172:NM[fliC H25], and Orough:NM[fliC H25]. O26:H11/NM[fliC H11] was the most common serotype associated with HUS (41% isolates). Five stx genotypes were identified, the most frequent being stx 2a (71.1% isolates). Most strains contained EHEC-hlyA encoding EHEC hemolysin, and a subset (all SF O157:NM and one O157:H7) harbored cdt-V encoding cytolethal distending toxin. espPα encoding serine protease EspPα was found in EHEC O157:H7, O26:H11/NM, and O145:H28, whereas O172:NM and Orough:NM strains contained espPγ. All isolates contained eae encoding adhesin intimin, which belonged to subtypes β (O26), γ (O55, O145, O157), γ2/θ (O111), and ε (O172, Orough). Loci encoding other adhesins (efa1, lpfA O26, lpfA O157OI-141, lpfA O157OI-154, iha) were usually associated with particular serotypes. Phylogenetic analysis demonstrated nine sequence types (STs) which correlated with serotypes. Of these, two STs (ST660 and ST1595) were not found in HUS-associated EHEC before.Conclusions/SignificanceEHEC strains, including O157:H7 and non-O157:H7, are frequent causes of D+ HUS in the Czech Republic. Identification of unusual EHEC serotypes/STs causing HUS calls for establishment of an European collection of HUS-associated EHEC, enabling to study properties and evolution of these important pathogens.

Investigation of enteropathogenic Escherichia coli and Shiga toxin-producingEscherichia coli associated with hemolytic uremic syndrome in İzmir Province, Turkey

“…The O157 serotypes of STEC are occasionally sorbitol-negative (24,25). However, sorbitolfermenting O157 strains have begun to be reported (26)(27)(28)(29). In our study, we reported that the E.coli O174:H21 strain (n = 1) that fermented sorbitol was isolated from the pediatrics service, but other STEC strains (n = 4) were not sorbitol-fermenting.…”

Characterization of the Shiga toxin-producing Escherichia coli O26 isolated from human in Poland between 1996 and 2014

“…STEC O26:H11/H-of ST29 represent a highly virulent clone found first in Germany in the 1990s as a cause of HUS (Zhang et al 2000;Bielaszewska et al 2013). It spread through Europe to Germany, Belgium, Czech Republic, Italy, Slovakia, Scotland and Switzerland where it frequently cause a HUS in human patients, even with fatal cases (Chase-Topping et al 2012;Bielaszewska et al 2013;Marejkov a et al 2013;Zweifel et al 2013). Latest studies performed in Switzerland shows that healthy cattle could constitute a potential reservoir and source of new STEC O26 pathotypes (Zweifel et al 2013).…”

“…Moreover, STEC O26 are one of serogroups of STEC responsible for most of the HUS cases occurring in the European countries (EFSA, 2013). In mid-1990s in Germany emerged a highly virulent clone of STEC O26:H11/H-Sequence Type 29 (ST 29) and spread over eight European countries (Zhang et al 2000;Chase-Topping et al 2012;Bielaszewska et al 2013;Marejkov a et al 2013;Zweifel et al 2013). This clone harbours stx2a as the only Shiga toxin gene and comprises characteristic plasmid genes profile (ehxA+, etpD+, katPÀ, espPÀ).…”

“…This clone harbours stx2a as the only Shiga toxin gene and comprises characteristic plasmid genes profile (ehxA+, etpD+, katPÀ, espPÀ). It has a strong associations with progression of infection to HUS (Chase-Topping et al 2012;Bielaszewska et al 2013;Marejkov a et al 2013;Zweifel et al 2013) .…”

Investigating the occurrence ofE. coliO157:H7 in the final effluents of two wastewater treatment plants

“…There are as well EHEC serotypes that are non-sorbitol fermenters (NSF) giving the characteristic growth on SMAC but are not H7 strain 30 well as non-O157 serotypes 31 . While E. coli O157 are popularly known to be non-sorbitol fermenting organisms 31 there are reports of Sorbitol fermenting (SF) E. coli O157 with HUS ability from Czech 32 and from Scotland 33 .…”