Molecular Characterization of the Enterohemolysin Gene (ehxA) in Clinical Shiga Toxin-Producing Escherichia coli Isolates
| Autor: | Milan Chromek, Yanwen Xiong, Andreas Matussek, Xiangning Bai, Sverker Hansson, Cecilia Jernberg, Anne Frykman, Chengsong Wan, Ji Zhang, Ying Hua |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Health
Toxicology and Mutagenesis clinical significance lcsh:Medicine ehxA Toxicology medicine.disease_cause Microbiology 03 medical and health sciences STX2 Genotype medicine Escherichia coli Gene Shiga toxin-producing Escherichia coli gene diversity 030304 developmental biology 0303 health sciences biology Foodborne pathogen 030306 microbiology enterohemolysin hemolytic uremic syndrome lcsh:R Shiga toxin Serotype O157 Mikrobiologi Shiga-toxin-producing Escherichia coli biology.protein |
| Zdroj: | Toxins Volume 13 Issue 1 Toxins, Vol 13, Iss 71, p 71 (2021) |
| ISSN: | 2072-6651 |
| Popis: | Shiga toxin (Stx)-producing Escherichia coli (STEC) is an important foodborne pathogen with the ability to cause bloody diarrhea (BD) and hemolytic uremic syndrome (HUS). Little is known about enterohemolysin-encoded by ehxA. Here we investigated the prevalence and diversity of ehxA in 239 STEC isolates from human clinical samples. In total, 199 out of 239 isolates (83.26%) were ehxA positive, and ehxA was significantly overrepresented in isolates carrying stx2a + stx2c (p < 0.001) and eae (p < 0.001). The presence of ehxA was significantly associated with BD and serotype O157:H7. Five ehxA subtypes were identified, among which, ehxA subtypes B, C, and F were overrepresented in eae-positive isolates. All O157:H7 isolates carried ehxA subtype B, which was related to BD and HUS. Three ehxA groups were observed in the phylogenetic analysis, namely, group Ⅰ (ehxA subtype A), group Ⅱ (ehxA subtype B, C, and F), and group Ⅲ (ehxA subtype D). Most BD- and HUS-associated isolates were clustered into ehxA group Ⅱ, while ehxA group Ⅰ was associated with non-bloody stool and individuals &ge 10 years of age. The presence of ehxA + eae and ehxA + eae + stx2 was significantly associated with HUS and O157:H7 isolates. In summary, this study showed a high prevalence and the considerable genetic diversity of ehxA among clinical STEC isolates. The ehxA genotypes (subtype B and phylogenetic group Ⅱ) could be used as risk predictors, as they were associated with severe clinical symptoms, such as BD and HUS. Furthermore, ehxA, together with stx and eae, can be used as a risk predictor for HUS in STEC infections. |
| Databáze: | OpenAIRE |
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