Occurrence of virulence-related sequences and phylogenetic analysis of commensal and pathogenic avian Escherichia coli strains (APEC)

Campos, Tatiana Amabile de; Lago, Juliana Carvalhães; Nakazato, Gerson; Stehling, Eliana Guedes; Brocchi, Marcelo; Castro, Antonio Fernando Pestana de; Silveira, Wanderley Dias da

doi:10.1590/s0100-736x2008001000015

Cited by 17 publications

(13 citation statements)

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“…Nonetheless, the presence of phylogroup A in approximately 25% of APEC isolates in our study, which is predominantly associated with commensal E. coli, could be ascribed to the origin of these strains as commensals that acquired virulencerelated genes [40].…”

Section: Discussionmentioning

confidence: 64%

Detection of phenotypes, virulence genes and phylotypes of avian pathogenic and human diarrheagenic Escherichia coli in Egypt

Ramadan

Awad

Ateya

2016

J Infect Dev Ctries

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Introduction: The purpose from this study was to determine phenotypes, intestinal virulence-associated genes, and phylotypic profiling of human diarrheagenic E. coli (DEC) and avian pathogenic E. coli (APEC). Methodology: A total of 108 chicken visceral organs (liver, spleen, heart) from 36 diseased birds (three organs per each bird) and 78 human stool samples (50 diarrheic patients and 28 healthy persons) were randomly collected during the first half of 2015 in the district of Mansoura city, Egypt. Conventional culturing, serotyping, and molecular characterization of virulence genes and phylogroups were performed. Results: Sixty-five (35%) biochemically identified E. coli isolates were detected from chicken visceral (29/108; 26.9%) and human stool samples (36/78; 46.2%). Serotypes O78, O2, and O1 were the most prevalent serotypes (62%) distinguished from APEC isolates, and only two similar serotypes (O119:H4 and O26:H11) were identified from both APEC and DEC isolates. By polymerase chain reaction (PCR), the respective percentages of 100 and 35 with eae and Shiga toxin genes were detected from APEC isolates while 50%, 27.8%, and 19.4% of human DEC isolates harbored eae, stx1, and stx2 genes, respectively. Phylogrouping revealed a significantly higher occurrence of pathogenic phylogroups (D and B2) in APEC (19/29; 65.5%) than in human DEC isolates (8/36; 22.2%). Conclusions: APEC isolates shared serotypes, virulence genes, and phylotypes with human DEC isolates, which is a subsequent potential public health concern. To the best of our knowledge, this is the first report in Egypt that determines virulence gene and phylogroup coexistence between APEC and DEC isolates.

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Section: Discussionmentioning

confidence: 64%

Detection of phenotypes, virulence genes and phylotypes of avian pathogenic and human diarrheagenic Escherichia coli in Egypt

Ramadan

Awad

Ateya

2016

J Infect Dev Ctries

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“…Other studies have also reported that the majority of CEC belong to group A (Rodriguez-Siek et al, 2005a;Sola-Gines et al, 2015). However, there are reports that the majority of CEC are group D (Campos et al, 2008;Clermont et al, 2000).…”

Section: Discussionmentioning

confidence: 94%

“…Campos et al (2008) reported 25% and 50% of APEC strains isolated from chickens with septicaemia and swollen-head syndrome, respectively, harboured the tsh gene and only 6% of AFEC. Similarly, a tsh prevalence of 55% was detected in Brazil and 53% in…”

Section: Curlimentioning

confidence: 99%

Studies on avian pathogenic Escherichia coli in commercial broiler chicken in South East Queensland

Awawdeh¹,

Turni²,

Henning³

et al.

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Avian pathogenic Escherichia coli (APEC) is the causative agent of avian colibacillosis, a localised or systemic infection resulting in clinical diseases such as colisepticemia, chronic respiratory disease and swollen-head syndrome. Globally, avian colibacillosis is the leading cause of morbidity and mortality in poultry, and it has been associated with massive economic losses and welfare problems.This organism is of public health significance as APEC is communicable to humans. The diagnosis of avian colibacillosis relies on clinical signs, typical pathological lesions and culture of E. coli from affected tissue(s). Antimicrobial therapy is often used both for treatment and control. Previous overseas studies have characterised APEC and identified virulence genes (VGs) that can be used as molecular markers for the identification of APEC. Little is known about APEC in broiler chickens in Australia.The aim of this thesis was to gain a better understanding of the epidemiology of APEC in Australian broiler flocks and how factors including presence of VGs and phylogenetic group can improve the identification of this pathotype in Australia. Firstly, three faecal DNA extraction methods were evaluated. Faeces were collected from healthy chickens and chickens with colibacillosis from commercial broiler farms in South East Queensland (SEQ). The extracted DNA was screened by a pentaplex-PCR for five APEC-associated VGs (iroN, iutA, iss, hlyF and ompT). DNA extracted from E. coli isolates cultured from the cloaca and organs of the birds were screened using the same PCR.Repeated bead beating plus column elution was the preferred DNA extraction method, as it yielded good PCR quality and adequate quantity DNA. However, identifying APEC by direct detection of the five VGs from the faecal material was not feasible as all of these genes were also detected in all of the birds. However, the VGs were more commonly detected in E. coli isolates cultured from birds with colibacillosis.A cross-sectional study was performed to estimate APEC farm-level prevalence in healthy broiler chickens in SEQ and to identify potential risk factors associated with the carriage of APEC. At the farm-level, all of the 40 farms sampled were positive for APEC, that is at least one bird per farm carried APEC, while the within-farm prevalence was 63% (95% Confidence Interval: 55.8, 70.2).Higher APEC within-farm bird-level prevalence was significantly associated with the usage of well water as a source of drinking water, failure to disinfect the water line after each flock, farm visitors not showering before entering the shed, distances greater than 20 metres between the car park and the poultry shed and the presence of wild birds within 50 metres of the shed. Chlorinating the drinking water combined with automatic water filtration reduced within-farm bird-level APEC prevalence. Page | 3Therefore, based on the results concluded from the multivariable model, improving biosecurity and water treatments might reduce APEC prevalence, decrease the risk of co...

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“…coli isolates are characterized into different pathotypes according to the presence of speciϐic virulence factors. The main pathotypes in swine diseases are enterotoxigenic E. coli (ETEC), characterized by the presence of the toxins STa, STb and LT and F4,F5,F6,F18 or F41 ϐimbria;enteropathogenic E. coli (EPEC), which carries the eae gene; Shiga toxigenic or Verotoxigenic E. coli (STEC or VTEC), characterized by the presence of factors such as F18a/b ϐimbria and Stx2 toxin, and ϐinally uropathogenic E. coli (UPEC), which carries at least one of the following genes: cnf, hly, bfp, eae, sfa, pap, iha and usp (Brito et al 1999, Campos et al 2008, Afset et al 2008.…”

Section: Introductionmentioning

confidence: 99%

Phylogenetic and pathotype analysis of Escherichia coli swine isolates from Southern Brazil

et al. 2012

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The current study evaluated the presence of virulence factors by a multiplex PCR technique and then phylogenetically classified the studied strains into groups A, B1, B2 and D, according to Clermont et al. (2000), in 152 intestinal and extraintestinal swine isolates of Escherichia coli. Seventy seven isolates tested were positive for virulence factors. Phylogenetic characterization placed 21 samples into group A, 65 into B1, 19 into B2 and 47 into D. Fourteen urine samples were classified as uropathogenic E. coli (UPEC), nine were both UPEC and enterotoxigenic E. coli (ETEC) and four were ETEC only. The most common phylogenetic classifications were B1 and D groups. Of the analyzed fecal samples, 25 were classified as ETEC. Phylogenetically, the group of higher occurrence was B1, followed by B2, A and D. For the small intestine samples, 20 were classified as ETEC. Phylogenetic analysis found groups B1 and A to be the most commons in these samples. Six isolated tissue samples were classified as ETEC and most of them were designated as group D by phylogenetic classification. The phylogenetic analysis could be employed in veterinary laboratories in the E. coli isolates screening, including the possibility of vaccine strain selection and epidemiological searches.

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Occurrence of virulence-related sequences and phylogenetic analysis of commensal and pathogenic avian Escherichia coli strains (APEC)

Cited by 17 publications

References 46 publications

Detection of phenotypes, virulence genes and phylotypes of avian pathogenic and human diarrheagenic Escherichia coli in Egypt

Detection of phenotypes, virulence genes and phylotypes of avian pathogenic and human diarrheagenic Escherichia coli in Egypt

Studies on avian pathogenic Escherichia coli in commercial broiler chicken in South East Queensland

Phylogenetic and pathotype analysis of Escherichia coli swine isolates from Southern Brazil

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