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Chaperone-Usher Pili Loci of Colonization Factor-Negative Human Enterotoxigenic Escherichia coli
- Source :
- Frontiers in Cellular and Infection Microbiology
- Publication Year :
- 2017
- Publisher :
- Frontiers Media SA, 2017.
-
Abstract
- Enterotoxigenic Escherichia coli (ETEC) is one of the most common causes of diarrhea worldwide. Among the 25 different ETEC adhesins, 22 are known as “colonization factors” (CFs), of which 17 are assembled by the chaperone-usher (CU) mechanism. Currently, there is no preventive therapy against ETEC, and CFs have been proposed as components for vaccine development. However, studies of diarrhea-causing ETEC strains worldwide indicate that between 15 and 50% of these are negative for known CFs, hindering the selection of the most widespread structures and suggesting that unknown adhesins remain to be identified. Here, we report the result of a comprehensive analysis of 35 draft genomes of ETEC strains which do not carry known adhesin genes; our goal was to find new CU pili loci. The phylogenetic profiles and serogroups of these strains were highly diverse, a majority of which produced only the heat-labile toxin. We identified 10 pili loci belonging to CU families β (1 locus), γ2 (7 loci), κ (1 locus), and π (1 locus), all of which contained the required number of open reading frames (ORFs) to encode functional structures. Three loci were variants of previously-known clusters, three had been only-partially described, and four are novel loci. Intra-loci genetic variability identified would allow the synthesis of up to 14 different structures. Clusters of putative γ2-CU pili were most common (23 strains), followed by putative β-CU pili (12 strains), which have not yet been fully characterized. Overall, our findings significantly increase the number of ETEC adhesion genes associated with human infections.
- Subjects :
- 0301 basic medicine
Microbiology (medical)
Immunology
Locus (genetics)
Biology
medicine.disease_cause
Microbiology
Genome
Pilus
03 medical and health sciences
adhesin
Enterotoxigenic Escherichia coli
medicine
Genetic variability
Adhesins, Bacterial
Gene
Original Research
genome analysis
Genetics
ETEC
Escherichia coli Proteins
Computational Biology
Bacterial adhesin
Open reading frame
chaperone-usher pili
030104 developmental biology
Infectious Diseases
Genetic Loci
Fimbriae, Bacterial
colonization factors
adhesin negative-ETEC
Genome, Bacterial
Molecular Chaperones
Subjects
Details
- ISSN :
- 22352988
- Volume :
- 6
- Database :
- OpenAIRE
- Journal :
- Frontiers in Cellular and Infection Microbiology
- Accession number :
- edsair.doi.dedup.....680614da6bb9f0647e73ce278e7ef2ce