New Insights into the Bacterial Fitness-Associated Mechanisms Revealed by the Characterization of Large Plasmids of an Avian Pathogenic E. coli

Mellata, Melha; Maddux, Jacob T.; Nam, Timothy; Thomson, Nicholas R.; Hauser, Heidi; Stevens, Mark P.; Mukhopadhyay, Suman; Sarker, Shameema; Crabbé, Aurélie; Nickerson, Cheryl A.; Santander, Javier; Curtiss, Roy

doi:10.1371/journal.pone.0029481

Cited by 26 publications

(27 citation statements)

References 88 publications

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“…Johnson et al (2007) also reported plasmid IncFIB type as the most prevalent among E. coli isolates of avian, human and poultry meat followed by IncI1. The virulence and resistant genes found in APEC have been detected on IncFIB plasmids, such as pAPEC-1 (Mellata et al, 2012). All plasmid replicons reported in the current study have been previously detected in E. coli isolates sourced from the environment, other animals and humans (Bortolaia et al, 2010;Garcia-Fernandez et al, 2008;Kluytmans et al, 2013;Lynne et al, 2012;Seni et al, 2016;Wang et al, 2013a;Woodford et al, 2007).…”

Section: Investigating the Prevalence Of Carriage Of Avian Pathogenicsupporting

confidence: 54%

“…However, their role in pathogenesis is not fully elucidated. Furthermore, some of the toxin genes (hly, cdt and cvaC) have been linked with large transmissible plasmids indicating that these VGs could be easily transferred to other strains and bacterial species (Ewers et al, 2010;Johnson et al, 2010;Mellata et al, 2012).…”

Section: Toxinsmentioning

confidence: 99%

“…These VGs are frequently associated with septicaemia as they assist the bacteria in avoiding being killed by the essential defence mechanisms present in the blood, including complement, antimicrobial peptides and other serum components (Boerlin and Reid-Smith, 2008;Jacobson et al, 1992;Jeffrey et al, 2002;Nolan et al, 2003). Several investigations have reported serum resistance VGs are widespread among APEC in comparison with AFEC and have suggested that these VGs contribute to APEC pathogenicity (Delicato et al, 2003;Dozois et al, 1992;Dziva and Stevens, 2008;Lynne et al, 2007;Mellata et al, 2003;Mellata et al, 2012;Nolan et al, 2002;Ozawa et al, 2008;Rocha et al, 2008;Rodriguez-Siek et al, 2005a;Skyberg et al, 2008;Tivendale et al, 2004;Wooley et al, 1992;Yaguchi et al, 2007;Yang et al, 2004;Zhao et al, 2005). Several VGs have been linked with serum resistance mechanisms and the association of each of the serum resistance VGs with APEC pathogenicity mechanisms have also been independently studied (Nakazato et al, 2009;Rocha et al, 2008).…”

Section: Serum Resistancementioning

confidence: 99%

“…Increased evidence has indicated that APEC-associated VGs are commonly clustered on plasmids, PAIs, or less often, the bacterial chromosome (Ewers et al, 2005;Johnson et al, 2008b;Mellata et al, 2012;Tivendale et al, 2009). Several studies have also found that the prevalence of VGs occurs at a higher rate among APEC in comparison with AFEC (Johnson et al, 2008b;Nolan et al, 2013).…”

Section: The Prevalence Of Apec Related Vgsmentioning

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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Section: Investigating the Prevalence Of Carriage Of Avian Pathogenicsupporting

confidence: 54%

Section: Toxinsmentioning

confidence: 99%

Section: Serum Resistancementioning

confidence: 99%

Section: The Prevalence Of Apec Related Vgsmentioning

confidence: 99%

See 2 more Smart Citations

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

Awawdeh¹,

Turni²,

Henning³

et al.

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“…Expression of these eit operons does not seem to be regulated by iron despite the presence of putative Fur boxes upstream of the eitA and eitD genes (65). IncFII plasmids harboring the eitABCD cluster are instead found in APEC and Klebsiella strains (125)(126)(127).…”

Section: Eitabcd Systemmentioning

confidence: 99%

Plasmid-Encoded Iron Uptake Systems

Lorenzo

Stork

2014

Microbiol Spectr

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Plasmids confer genetic information that benefits the bacterial cells containing them. In pathogenic bacteria, plasmids often harbor virulence determinants that enhance the pathogenicity of the bacterium. The ability to acquire iron in environments where it is limited, for instance the eukaryotic host, is a critical factor for bacterial growth. To acquire iron, bacteria have evolved specific iron uptake mechanisms. These systems are often chromosomally encoded, while those that are plasmid-encoded are rare. Two main plasmid types, ColV and pJM1, have been shown to harbor determinants that increase virulence by providing the cell with essential iron for growth. It is clear that these two plasmid groups evolved independently from each other since they do not share similarities either in the plasmid backbones or in the iron uptake systems they harbor. The siderophores aerobactin and salmochelin that are found on ColV plasmids fall in the hydroxamate and catechol group, respectively, whereas both functional groups are present in the anguibactin siderophore, the only iron uptake system found on pJM1-type plasmids. Besides siderophore-mediated iron uptake, ColV plasmids carry additional genes involved in iron metabolism. These systems include ABC transporters, hemolysins, and a hemoglobin protease. ColV-and pJM1-like plasmids have been shown to confer virulence to their bacterial host, and this trait can be completely ascribed to their encoded iron uptake systems.

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