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Microevolution of epidemiological highly relevant non-O157 enterohemorrhagic Escherichia coli of serogroups O26 and O111
- Source :
- International Journal of Medical Microbiology. 308:1085-1095
- Publication Year :
- 2018
- Publisher :
- Elsevier BV, 2018.
-
Abstract
- Enterohemorrhagic Escherichia coli (EHEC) are a cause of bloody diarrhea, hemorrhagic colitis (HC) and the potentially fatal hemolytic uremic syndrome (HUS). While O157:H7 is the dominant EHEC serotype, non-O157 EHEC have emerged as serious causes of disease. In Germany, the most important non-O157 O-serogroups causing one third of EHEC infections, including diarrhea as well as HUS, are O26, O103, O111 and O145. Interestingly, we identified EHEC O-serogroups O26 and O111 in one single sequence type complex, STC29, that also harbours atypical enteropathogenic E. coli (aEPEC). aEPEC differ from typical EHEC merely in the absence of stx-genes. These findings inspired us to unravel a putative microevolutionary scenario of these non-O157 EHEC by whole genome analyses. Analysis of single nucleotide polymorphisms (SNPs) of the maximum common genome (MCG) of 20 aEPEC (11 human/ 9 bovine) and 79 EHEC (42 human/ 36 bovine/ 1 food source) of STC29 identified three distinct clusters: Cluster 1 harboured strains of O-serogroup O111, the central Cluster 2 harboured only O26 aEPEC strains, while the more heterogeneous Cluster 3 contained both EHEC and aEPEC strains of O-serogroup O26. Further combined analyses of accessory virulence associated genes (VAGs) and insertion sites for mobile genetic elements suggested a parallel evolution of the MCG and the acquisition of virulence genes. The resulting microevolutionary model suggests the development of two distinct EHEC lineages from one common aEPEC ancestor of ST29 by lysogenic conversion with stx-converting bacteriophages, independent of the host species the strains had been isolated from. In conclusion, our cumulative data indicate that EHEC of O-serogroups O26 and O111 of STC29 originate from a common aEPEC ancestor and are bona fide zoonotic agents. The role of aEPEC in the emergence of O26 and O111 EHEC should be considered for infection control measures to prevent possible lysogenic conversion with stx-converting bacteriophages as major vehicle driving the emergence of EHEC lineages with direct Public Health consequences.
- Subjects :
- 0301 basic medicine
Microbiology (medical)
Serotype
Transposable element
030106 microbiology
Virulence
Biology
Escherichia coli O157
Serogroup
medicine.disease_cause
Polymorphism, Single Nucleotide
Microbiology
Genome
Evolution, Molecular
03 medical and health sciences
fluids and secretions
Germany
Zoonoses
hemic and lymphatic diseases
Lysogenic cycle
medicine
Animals
Humans
Gene
Escherichia coli
Escherichia coli Infections
Genetics
Whole Genome Sequencing
General Medicine
biochemical phenomena, metabolism, and nutrition
bacterial infections and mycoses
Infectious Diseases
Hemolytic-Uremic Syndrome
bacteria
Cattle
Mobile genetic elements
Genome, Bacterial
Subjects
Details
- ISSN :
- 14384221
- Volume :
- 308
- Database :
- OpenAIRE
- Journal :
- International Journal of Medical Microbiology
- Accession number :
- edsair.doi.dedup.....5cef66e60048f43e75f26bcce3d2cb74