The chicken as a natural model for extraintestinal infections caused by avian pathogenic Escherichia coli (APEC)

Antão, Esther-Maria; Glodde, Susanne; Li, Ganwu; Sharifi, Reza; Homeier, Timo; Laturnus, Claudia; Diehl, Ines; Bethe, Astrid; Philipp, Hans C.; Preisinger, Rudolf; Wieler, Lothar H.; Ewers, Christa

doi:10.1016/j.micpath.2008.08.005

Cited by 110 publications

(105 citation statements)

References 38 publications

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“…Avian pathogenic Escherichia coli (APEC), the causative agent of avian colibacillosis (Antão et al, 2008;Dho-Moulin and Fairbrother, 1999;Ewers et al, 2004;Kabir, 2010;Nolan et al, 2013), is a subpathotype of extraintestinal pathogenic E. coli (ExPEC). It is considered a potential zoonotic agent (Johnson et al, 2008b;Nolan et al, 2013;Rodriguez-Siek et al, 2005a).…”

Section: Chapter 1: Literature Reviewmentioning

confidence: 99%

“…A mortality rate of 3.3% was reported in birds due to colibacillosis in Bangladesh (Rashid et al, 2013) and mortality rates of up to 10% have been reported in Denmark and Italy (Stokholm et al, 2010;Zanella et al, 2000). The disease is responsible for 2% -3% decreases in egg production and the costs associated with prevention/control, vaccination and treatment are substantial (Antão et al, 2008;Ewers et al, 2004;Gross, 1957;Kabir, 2010;Nolan et al, 2013;Stokholm et al, 2010;Zanella et al, 2000).…”

Section: Economic Significance Of Avian Colibacillosismentioning

confidence: 99%

“…Globally, the economic, public health and animal welfare significance of avian colibacillosis, has led to a number of studies from United States of America aiming to define APEC and to identify pathogenicity mechanisms (Jeffrey et al, 1999;Kariyawasam and Nolan, 2009;Norton et al, 2000). Studies have identified a large number of VGs in E. coli cultured from birds with avian colibacillosis (Antão et al, 2008;Dissanayake et al, 2014; and relevance of these VGs in the pathogenicity of avian colibacillosis is still poorly understood and the majority of studies on APEC and APEC-associated VGs are descriptive (Dozois et al, 1994;Jeffrey et al, 1999;Norton et al, 2000;Obeng et al, 2012;Zhao et al, 2009)…”

Section: Avian Pathogenic E Coli (Apec)mentioning

confidence: 99%

“…experimental studies have enhanced the understanding of the APEC pathogenicity mechanisms (Antão et al, 2008;Ask et al, 2006;Musa et al, 2009). However, no single or specific set of VGs have been systematically linked with APEC pathogenicity.…”

Section: Few In Vivomentioning

confidence: 99%

“…Although a number of studies have aimed to identify the virulence mechanisms of APEC, it remains an illdefined pathotype Rodriguez-Siek et al, 2005a). Healthy chickens and their surrounding farm environment can be colonised by APEC without the chickens displaying any signs of disease (Antão et al, 2008). Recent studies have suggested that the presence of various virulence genes (VGs) were useful markers for the detection of APEC and can differentiate between APEC and avian faecal E. coli (AFEC) (Circella et al, 2012;Ewers et al, 2005;Johnson et al, 2008b;Rodriguez-Siek et al, 2005a and two iron acquisition system genes (iutA and iroN), which could be used as a diagnostic tool for the identification of APEC.…”

Section: Introductionmentioning

confidence: 99%

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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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