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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Variants of astA gene among extra-intestinal Escherichia coli of human and avian origin

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Author(s):
Maluta, Renato Pariz ; Leite, Janaina Luisa ; Galvao Rojas, Thais Cabrera ; Affonso Scaletsky, Isabel Cristina ; Lopes Guastalli, Elisabete Aparecida ; Ramos, Marcelo de Carvalho ; da Silveira, Wanderley Dias
Total Authors: 7
Document type: Journal article
Source: FEMS Microbiology Letters; v. 364, n. 6 MAR 2017.
Web of Science Citations: 4
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. (AU)

FAPESP's process: 12/04931-6 - Molecular characterization of avian pathogenic (APEC) and human uropathogenic (UPEC) Escherichia coli strains
Grantee:Wanderley Dias da Silveira
Support Opportunities: Regular Research Grants