Evidence map›Paper›PMID 26438110›Full record

ArticleBMC microbiology2015

Genetic analysis of enteropathogenic Escherichia coli (EPEC) adherence factor (EAF) plasmid reveals a new deletion within the EAF probe sequence among O119 typical EPEC strains.

Nathalia B Teixeira, Thais C G Rojas, Wanderley D da Silveira, Cecília Matheus-Guimarães, Neusa P Silva, Isabel C A Scaletsky

Open access · goldAbstract read
In one paragraph

Article in BMC microbiology, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

0numbers the graph read from it
0cells of the map it votes in
3citing papers in PubMed
1.2field-weighted citation impact, top 22% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

3 citing papers in PubMed, 13 citations in OpenAlex.

  1. Article
  2. Article
  3. Gastroenterology and hepatology from bed to bench · 2017
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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

6 authors at 2 institutions in 1 country.

Nathalia B TeixeiraDepartamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, Rua Botucatu, 862, 3 andar, São Paulo, 04023-062, São Paulo, Brazil. na_tx0402@yahoo.com.br.
Thais C G RojasDepartamento de Genética, Evolução e Bioagentes, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, Brazil. thaiscjrojas@gmail.com.
Wanderley D da SilveiraDepartamento de Genética, Evolução e Bioagentes, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, Brazil. wds@unicamp.br.
Cecília Matheus-GuimarãesDepartamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, Rua Botucatu, 862, 3 andar, São Paulo, 04023-062, São Paulo, Brazil. cmatheus@globo.com.
Neusa P SilvaDisciplina de Reumatologia, Universidade Federal de São Paulo, São Paulo, Brazil. npsilva@unifesp.br.
Isabel C A ScaletskyDepartamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, Rua Botucatu, 862, 3 andar, São Paulo, 04023-062, São Paulo, Brazil. scaletskyunifesp@gmail.com.
Universidade Federal de São Paulo · BRUniversidade Estadual de Campinas (UNICAMP) · BR

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundEnteropathogenic Escherichia coli (EPEC) are classified into typical and atypical strains based on the presence of the E. coli adherence factor (EAF) plasmid. The EAF plasmid contains the bfp (bundle-forming pilus) operon and the perABC (plasmid encoded regulator) gene cluster. A 1-kb cryptic region of EAF plasmid has been widely used as a genetic probe for EPEC detection. However, some EPEC strains may harbor an EAF plasmid lacking the EAF probe sequence, which makes the differentiation between typical and atypical a complex task. In this study, we report the genetic analysis of the EAF plasmid-encoded genes in a collection of EPEC clinical isolates.

methodsA total of 222 EPEC clinical isolates, which were previously classified as typical (n=70) or atypical (n=152) by EAF probe reactivity, were screened for the presence of different EAF sequences by PCR and DNA hybridization.

resultsAll typical strains possessed intact bfpA and perA genes, and most of them were positive in the PCR for EAF probe sequence. However, a subset of 30 typical strains, 22 of which belonged to O119 serogroup, presented a 1652 pb deletion in the region between 1093-bp downstream perC and 616-bp of the EAF fragment. The bfpA, bfpG, and per genes were found in all typical strains. In addition, 32 (21%) atypical strains presented the perA gene, and 20 (13.2%) also presented the bfpA gene. Among the 32 strains, 16 belonged to the O119:H2, O119:HND, and ONT:HND serotypes. All 32 atypical strains contained perA mutation frameshifts and possessed an IS1294 element upstream of the per operon as detected by PCR followed by restriction fragment length polymorphism (RFLP) typing and multiplex PCR. Among the 20 bfpA probe-positive strains, eight O119 strains possessed deletion in the bfp operon at the 3'end of bfpA due to an IS66 element.

conclusionOur data show that typical O119 strains may contain a deletion within the EAF probe sequence not previously reported. This new finding suggests that care should be taken when using the previously described EAF PCR assay in epidemiological studies for the detection of typical O119 strains. In addition, we were able to confirm that some atypical strains carry vestiges of the EAF plasmid.

Indexed as

PlasmidsSequence DeletionAdhesins, BacterialEnteropathogenic Escherichia coliEscherichia coli InfectionsFalse Negative ReactionsMolecular Diagnostic TechniquesMolecular Sequence DataMultigene FamilyNucleic Acid HybridizationOligonucleotide ProbesPolymerase Chain ReactionSequence Analysis, DNAAdhesins, BacterialOligonucleotide Probes

Identifiers

PMID26438110
PMCPMC4594896
OpenAlexW2101432503

What OpenQuestion holds

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LicenceCC BY
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Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.