HlyF Produced by Extraintestinal Pathogenic<i>Escherichia coli</i>Is a Virulence Factor That Regulates Outer Membrane Vesicle Biogenesis

Murase, Kazunori; Martín, Patricia; Porcheron, Gaëlle; Houle, Sébastien; Helloin, Emmanuelle; Pénary, Marie; Nougayrède, Jean-Philippe; Dozois, Charles M.; Hayashi, Tetsuya; Oswald, Éric

doi:10.1093/infdis/jiv506

Cited by 53 publications

(64 citation statements)

References 42 publications

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“…The minimal combination of plasmidic genes common to all strains was the association of ompT p and hlyF , which might represent a beneficial influence on the intestinal pathogenic virulence of E. coli O80:H2 . Chromosomal ompT and hlyF are involved in the secretion of outer membrane vesicles, which might serve as transporters of toxins and thus might boost the virulence of Stx-producing E. coli ( 30 , 31 ). Whether ompT p has a similar role remains to be further investigated.…”

Section: Discussionmentioning

confidence: 99%

EnterohemorrhagicEscherichia coliHybrid Pathotype O80:H2 as a New Therapeutic Challenge

Soysal¹,

Mariani‐Kurkdjian²,

Smail³

et al. 2016

Emerg. Infect. Dis.

103

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Section: Discussionmentioning

confidence: 99%

EnterohemorrhagicEscherichia coliHybrid Pathotype O80:H2 as a New Therapeutic Challenge

Soysal¹,

Mariani‐Kurkdjian²,

Smail³

et al. 2016

Emerg. Infect. Dis.

103

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“…OMVs are derived from the outer membrane and include mainly materials from the outer membrane and periplasm. In addition, although precise mechanisms remain unknown, gene products that positively affect OMVs production have been reported, such as HlyF of extraintestinal pathogenic E. coli and OmpT of EHEC (Murase et al, 2016;Premjani, Tilley, Gruenheid, Le Moual, & Samis, 2014). In addition, OMVs has been shown to deliver virulence factors to host cells (Jager, Keese, Roessle, Steinert, & Schromm, 2015;Rompikuntal et al, 2015).…”

Section: Introductionmentioning

confidence: 99%

“…The production of OMVs is affected by a variety of proteins, which are involved in cross-linking between the outer membrane and peptidoglycan, lipopolysaccharide (LPS) synthesis and remodelling, and oxidative stress (Elhenawy et al, 2016;Kulp et al, 2015;Schwechheimer, Rodriguez, & Kuehn, 2015). In addition, although precise mechanisms remain unknown, gene products that positively affect OMVs production have been reported, such as HlyF of extraintestinal pathogenic E. coli and OmpT of EHEC (Murase et al, 2016;Premjani, Tilley, Gruenheid, Le Moual, & Samis, 2014). Deletion of the ompT gene in EHEC markedly decreases the production of OMVs and changes vesicle size (Premjani et al, 2014).…”

mentioning

confidence: 99%

Enterohaemorrhagic Escherichia coli produces outer membrane vesicles as an active defence system against antimicrobial peptide LL-37

Urashima

Sanou

Yen

et al. 2017

Cellular Microbiology

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Antimicrobial peptides (AMPs) are important components of the innate immune system. Enterohaemorrhagic Escherichia coli (EHEC), a food-borne pathogen causing serious diarrheal diseases, must overcome attack by AMPs. Here, we show that resistance of EHEC against human cathelicidin LL-37, a primary AMP, was enhanced by butyrate, which has been shown to act as a stimulant for the expression of virulence genes. The increase of resistance depended on the activation of the ompT gene, which encodes the outer membrane protease OmpT for LL-37. The expression of the ompT gene was enhanced through the activation system for virulence genes. The increase in ompT expression did not result in an increase in OmpT protease in bacteria but in enhancement of the production of OmpT-loaded outer membrane vesicles (OMVs), which primarily contributed to the increase in LL-37-resistance. Furthermore, a sublethal dosage of LL-37 stimulated the production of OMVs. Finally, we showed that OMVs produced by OmpT-positive strains protect the OmpT-negative strain, which is susceptible to LL-37 by itself more efficiently than OMVs from the ompT mutant. These results indicate that EHEC enhances the secretion of OmpT-loaded OMVs in coordination with the activation of virulence genes during infection and blocks bacterial cell attack by LL-37.

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“…In an infectious chick embryo model, the transcription of hlyF was strongly upregulated, which could suggest an essential role of this gene in the establishment of avian colibacillosis (Skyberg et al, 2008). A recent study investigated the role of hlyF genes in establishing an extraintestinal infection and reported that this gene was directly involved in the production of outer membrane vesicles (Murase et al, 2016). This outer membrane acts as a channel to deliver bacterial virulence factors into the host, leading to infection (Murase et al, 2016).…”

Section: Toxinsmentioning

confidence: 99%

“…A recent study investigated the role of hlyF genes in establishing an extraintestinal infection and reported that this gene was directly involved in the production of outer membrane vesicles (Murase et al, 2016). This outer membrane acts as a channel to deliver bacterial virulence factors into the host, leading to infection (Murase et al, 2016). …”

Section: Toxinsmentioning

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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HlyF Produced by Extraintestinal PathogenicEscherichia coliIs a Virulence Factor That Regulates Outer Membrane Vesicle Biogenesis

Cited by 53 publications

References 42 publications

EnterohemorrhagicEscherichia coliHybrid Pathotype O80:H2 as a New Therapeutic Challenge

EnterohemorrhagicEscherichia coliHybrid Pathotype O80:H2 as a New Therapeutic Challenge

Enterohaemorrhagic Escherichia coli produces outer membrane vesicles as an active defence system against antimicrobial peptide LL-37

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

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