Risk factors associated with colibacillosis outbreaks in caged layer flocks

Vandekerchove, Dominique; Herdt, Peter De; Laevens, Hans; Pasmans, Frank

doi:10.1080/0307945042000220679

Cited by 32 publications

(51 citation statements)

References 12 publications

(20 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Colibacillosis is a disease of severe economic significance to all poultry producers worldwide and is characterized by a diverse array of lesions. Recent reports in Western Europe implicate a resurgence of this disease in the poultry industry, particularly in chicken layers (Zanella et al, 2000;Vandekerchove et al, 2004;Jordan et al, 2005). Depending on the virulence status of the strain, host status and presence and type of predisposing factors, the infection manifests as an initial septicaemia that is followed by either sudden death or localized inflammation in multiple organs.…”

Section: Introductionmentioning

confidence: 99%

Colibacillosis in poultry: unravelling the molecular basis of virulence of avian pathogenicEscherichia coliin their natural hosts

Dziva¹,

Stevens²

2008

Avian Pathology

299

222

View full text Add to dashboard Cite

Avian colibacillosis is caused by a group of pathogens designated avian pathogenic Escherichia coli (APEC). Despite being known for over a century, avian colibacillosis remains one of the major endemic diseases afflicting the poultry industry worldwide. Autologous bacterins provide limited serotype-specific protection, yet multiple serogroups are associated with disease, especially O1, O2 and O78 among many others. Experimental infection models have facilitated the identification of some key APEC virulence genes and have allowed testing of vaccine candidates. Well-recognized virulence factors include Type 1 (F1) and P (Pap/ Prs) fimbriae for colonization, IbeA for invasion, iron acquisition systems, TraT and Iss for serum survival, K and O antigens for anti-phagocytic activity, and a temperature-sensitive haemagglutinin of imprecise function. Intriguingly, these factors do not occur universally among APEC, suggesting the presence of multiple alternative mechanisms mediating pathogenicity. The recent availability of the first complete APEC genome sequence can be expected to accelerate the identification of bacterial genes expressed during infection and required for virulence. High-throughput molecular approaches like signature-tagged transposon mutagenesis have already proved invaluable in revealing portfolios of genes expressed by pathogenic bacteria during infection, and this has enabled identification of APEC O2 factors required for septicaemia in the chicken model. Complimentary approaches, such as in vivo-induced antigen technology, exist to define the activities of APEC in vivo. In recent years, reverse vaccinology and immuno-proteomic approaches have also enabled identification of novel vaccine candidates in other bacterial pathogens. Collectively, such information provides the basis for the development or improvement of strategies to control APEC infections in the food-producing avian species.

show abstract

Section: Introductionmentioning

confidence: 99%

Colibacillosis in poultry: unravelling the molecular basis of virulence of avian pathogenicEscherichia coliin their natural hosts

Dziva¹,

Stevens²

2008

Avian Pathology

299

222

View full text Add to dashboard Cite

show abstract

“…Traditionally, E. coli has been regarded as an opportunistic pathogen, and colibacillosis regarded a secondary disease following a primary infection (Dwars et al, 2009) or lack of appropriate management (Vandekerchove et al, 2004b). However, an increased significance, and a primary rather than secondary role of APEC in layers, has been reported both from the Netherlands and Denmark (Vandekerchove et al, 2005;Gregersen et al, 2010a).…”

mentioning

confidence: 99%

Multi-locus sequence typing and plasmid profile characterization of avian pathogenicEscherichia coliassociated with increased mortality in free-range layer flocks

et al. 2011

View full text Add to dashboard Cite

Avian pathogenic Escherichia coli strains originating from 10 free-range layer flocks were characterized by multi-locus sequence typing and plasmid profile analysis to investigate their phylogenetic relationship and diversity, respectively. In addition to colibacillosis, all flocks tested positive for antibodies against avian metapneumovirus (aMPV) during production, and six of the flocks were concurrently affected by histomonosis. Accumulated average mortality for flocks concurrently affected by colibacillosis and histomonosis made up 17.4%, while the average mortality for E. coli-infected flocks was 16.5%. A total of eight different sequence types (STs) and 47 different plasmid profiles were demonstrated among the E. coli isolates. Within each flock between one and four different STs and between three and 13 different plasmid profiles were demonstrated. A statistical significant difference in STs and plasmid profile diversity of the population of E. coli was not demonstrated between flocks affected by histomonosis compared with histomonosis-free flocks. Only minor clonal diversity was demonstrated for each flock, and in all but one flock colibacillosis started before antibodies against aMPV were detected. All isolates, except two, carried plasmids greater than 100 kb, but only a single plasmid replicon type, IncFIB, was demonstrated, suggesting plasmids representing this type might represent a common pathogenicity factor for the different STs of E. coli. Within each flock a clonal tendency was observed, indicating that only certain clones of E. coli possess a significant pathogenic potential. These clones act as primary rather than secondary pathogens, resulting in colibacillosis without predisposing factors, including histomonosis and aMPV.

show abstract

“…Impaired biosecurity protocols on farms which allow birds to contact wild birds, rodents, insects or any other wild animals are potential risk factors for APEC infections (Jiang et al 2014;Wang et al 2013). Generally, the animals and insects act as vectors to introduce and/or spread the disease among flocks (Barnes, 2013;Vandekerchove et al 2004a). It is not only the wild animal that can introduce colibacillosis, but infectious diseases can also be introduced through feed, hence strict biosecurity measures for feed are paramount (Vandekerchove et al, 2004;Wang et al, 2013).…”

Section: Risk and Predisposing Factors Associated With Avian Colibacimentioning

confidence: 99%

“…A number of overseas studies identified vectors humans (farm worker and visitors), wild birds and rodents, source and type of treatment(s) applied to the drinking water and unfavourable housing conditions as major risk factors associated with avian colibacillosis (Kemmett et al, 2013;Nolan et al, 2013;Vandekerchove et al, 2004a). Low levels of APEC on overseas poultry farms, is associated with strict farm biosecurity and management practices, such as control of vectors by minimising bird interaction with other animals and hygienic cleaning protocols Vandekerchove et al, 2004a;Zanella et al, 2000). However, little knowledge is available in regards to the potential predisposing risk factors (biosecurity and farm manageme nt protocols and environmental factors) associated with APEC among commercial broiler chicken flocks in Australia.…”

Section: Chapter 1: Literature Reviewmentioning

confidence: 99%

“…The severity of colibacillosis in chickens depends on the pathogenicity of the APEC, the chicken's immune status and the presence of predisposing risk factors, such as poor chicken welfare, immunosuppression and co-infections that can increase host susceptibility (Dho-Moulin and Fairbrother, 1999;Ewers et al, 2004;Guabiraba and Schouler, 2015;Nolan et al, 2013;Vandekerchove et al, 2004a). A number of overseas studies identified vectors humans (farm worker and visitors), wild birds and rodents, source and type of treatment(s) applied to the drinking water and unfavourable housing conditions as major risk factors associated with avian colibacillosis (Kemmett et al, 2013;Nolan et al, 2013;Vandekerchove et al, 2004a).…”

Section: Chapter 1: Literature Reviewmentioning

confidence: 99%

See 1 more Smart Citation

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

Awawdeh¹,

Turni²,

Henning³

et al.

View full text Add to dashboard Cite

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...

show abstract

Risk factors associated with colibacillosis outbreaks in caged layer flocks

Cited by 32 publications

References 12 publications

Colibacillosis in poultry: unravelling the molecular basis of virulence of avian pathogenicEscherichia coliin their natural hosts

Colibacillosis in poultry: unravelling the molecular basis of virulence of avian pathogenicEscherichia coliin their natural hosts

Multi-locus sequence typing and plasmid profile characterization of avian pathogenicEscherichia coliassociated with increased mortality in free-range layer flocks

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

Contact Info

Product

Resources

About