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Variants of astA gene among extra-intestinal Escherichia coli of human and avian origin.
- Source :
-
FEMS microbiology letters [FEMS Microbiol Lett] 2017 Mar 01; Vol. 364 (6). - Publication Year :
- 2017
-
Abstract
- Many Escherichia coli strains harbour astA, which is the gene encoding the enteroaggregative E. coli heat-stable enterotoxin (EAST1). This gene is embedded in a putative transposase (ORF1) and presents polymorphism in diarrheagenic strains. Although astA and orf1 are detected in extraintestinal strains, little is known about polymorphism and differential gene transcription in this pathotype. In the present work, extraintestinal E. coli from humans (ExPEC - Extraintestinal Pathogenic E. coli) and poultry (APEC - Avian Pathogenic E. coli) were assayed to verify the presence of astA/orf1 and possible polymorphisms in these genes. Three astA/orf1 patterns were detected via Sanger sequencing. Pattern 1 was novel and represented an astA pseudogene. Pattern 2 and pattern 3 presented distinct amino acids within the reading frame encoding astA and were identical to the sequences found in EAEC 17-2 and EAEC 042, respectively. Regarding the frame encoding ORF1, all mutations detected in the three patterns were neutral. The transcripts of astA/orf1 in vitro were underregulated in strains possessing the pattern 1 sequence. The results demonstrate that the same astA sequences may be detected in diarrheagenic and extra-intestinal E. coli. However, extraintestinal isolates may also present an astA pseudogene that has not been reported in diarrheagenic E. coli.<br /> (© FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
- Subjects :
- Amino Acid Sequence
Animals
Bacterial Toxins chemistry
Base Sequence
Enterotoxins chemistry
Escherichia coli classification
Escherichia coli Proteins chemistry
Genes, Bacterial
Humans
Models, Molecular
Protein Conformation
Sequence Analysis, DNA
Serogroup
Virulence genetics
Bacterial Toxins genetics
Enterotoxins genetics
Escherichia coli genetics
Escherichia coli Proteins genetics
Genetic Variation
Subjects
Details
- Language :
- English
- ISSN :
- 1574-6968
- Volume :
- 364
- Issue :
- 6
- Database :
- MEDLINE
- Journal :
- FEMS microbiology letters
- Publication Type :
- Academic Journal
- Accession number :
- 27993929
- Full Text :
- https://doi.org/10.1093/femsle/fnw285