Identification of Human-Pathogenic Strains of Shiga Toxin-Producing Escherichia coli from Food by a Combination of Serotyping and Molecular Typing of Shiga Toxin Genes
| Autor: | Katja Steege, Nadine Albrecht, Karin Pries, Lothar Beutin, Sabine Haby, Gladys Krause, Angelika Miko |
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| Rok vydání: | 2007 |
| Předmět: |
Meat
animal diseases Molecular Sequence Data Virulence Food Contamination Biology Shiga Toxin 1 medicine.disease_cause Polymerase Chain Reaction Shiga Toxin 2 Applied Microbiology and Biotechnology Microbiology chemistry.chemical_compound fluids and secretions Shiga-like toxin Cheese STX2 Escherichia coli medicine Animals Humans Typing Serotyping Genotyping Ecology Escherichia coli Proteins Shiga toxin Sequence Analysis DNA biochemical phenomena metabolism and nutrition bacterial infections and mycoses Bacterial Typing Techniques Milk chemistry Food Microbiology biology.protein bacteria Cattle Restriction fragment length polymorphism Polymorphism Restriction Fragment Length Food Science Biotechnology |
| Zdroj: | Applied and Environmental Microbiology. 73:4769-4775 |
| ISSN: | 1098-5336 0099-2240 |
| DOI: | 10.1128/aem.00873-07 |
| Popis: | We examined 219 Shiga toxin-producing Escherichia coli (STEC) strains from meat, milk, and cheese samples collected in Germany between 2005 and 2006. All strains were investigated for their serotypes and for genetic variants of Shiga toxins 1 and 2 (Stx1 and Stx2). stx 1 or variant genes were detected in 88 (40.2%) strains and stx 2 and variants in 177 (80.8%) strains. Typing of stx genes was performed by stx -specific PCRs and by analysis of restriction fragment length polymorphisms (RFLP) of PCR products. Major genotypes of the Stx1 ( stx 1 , stx 1c , and stx 1d ) and the Stx2 ( stx 2 , stx 2d , stx 2-O118 , stx 2e , and stx 2g ) families were detected, and multiple types of stx genes coexisted frequently in STEC strains. Only 1.8% of the STEC strains from food belonged to the classical enterohemorrhagic E. coli (EHEC) types O26:H11, O103:H2, and O157:H7, and only 5.0% of the STEC strains from food were positive for the eae gene, which is a virulence trait of classical EHEC. In contrast, 95 (43.4%) of the food-borne STEC strains carried stx 2 and/or mucus-activatable stx 2d genes, an indicator for potential high virulence of STEC for humans. Most of these strains belonged to serotypes associated with severe illness in humans, such as O22:H8, O91:H21, O113:H21, O174:H2, and O174:H21. stx 2 and stx 2d STEC strains were found frequently in milk and beef products. Other stx types were associated more frequently with pork ( stx 2e ), lamb, and wildlife meat ( stx 1c ). The combination of serotyping and stx genotyping was found useful for identification and for assignment of food-borne STEC to groups with potential lower and higher levels of virulence for humans. |
| Databáze: | OpenAIRE |
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