(Patho-)Genomics of Escherichia coli

Dobrindt, Ulrich

doi:10.1016/j.ijmm.2005.07.009

Cited by 144 publications

(127 citation statements)

References 103 publications

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“…Our study shows that the exact role of ExPEC-associated virulence genes and adherence factors is unknown and it seems unlikely that one set of factors determines the virulence properties and epidemiological success of certain sequence types (Dobrindt, 2005). Future investigations should be undertaken to further study the microbiological and ecological factors that make certain sequence types such as ST131 among E. coli such successful pathogens.…”

Section: Resultsmentioning

confidence: 91%

Virulence potential and adherence properties of Escherichia coli that produce CTX-M and NDM β-lactamases

Peirano

Mulvey

Armstrong

et al. 2013

Journal of Medical Microbiology

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The success of certain sequence types such as ST131 that produce CTX-M or NDM blactamases, and ST405 that produce CTX-M b-lactamases, among extraintestinal Escherichia coli (ExPEC) had previously been linked to a combination of antimicrobial resistance and certain virulence factors. The adherence properties of these sequence types to gastro-intestinal epithelial cells had not been investigated. A study was therefore designed to investigate the phylogenetic groups, virulence factors and adherence properties of E. coli sequence types ST101, ST131 and ST405 that produce CTX-M-15 and NDM-1. Our results show that ST131 was positive for phylogenetic group B2, ST101 for B1 and ST404 for D. ST131 had more virulence factors than ST101 or ST405. Interestingly, ST101 adhered more avidly to HEp-2 and Caco-2 cells than did ST131 and ST405. Our study showed that adherence to gastro-intestinal cells did not seem to play an important role in the worldwide epidemiological success of ST131 and ST405. The exact role of ExPEC-associated virulence genes is unknown and it is unlikely that one set of factors determines the virulence properties and epidemiological success of certain sequence types. Future investigations should be undertaken to study the microbiological and ecological factors that make certain sequence types among ExPEC such successful pathogens. INTRODUCTIONEscherichia coli is an important cause of community and hospital-associated human infections and is responsible for considerable morbidity, mortality and increased health costs (Russo & Johnson, 2003). The management of infections due to extraintestinal E. coli (ExPEC) has been complicated by the emergence of antimicrobial resistance, especially since the late 1990s .b-Lactamases are bacterial enzymes that inactivate blactam antibiotics by hydrolysis, which results in ineffective compounds. Most important within ExPEC is the increasing recognition of isolates producing 'newer' b-lactamases that consist of extended-spectrum b-lactamases (ESBLs) (e.g. CTX-M types) and carbapenemases [e.g. metallo-blactamases (MBLs) such as the NDMs, serine b-lactamases such as KPCs and OXA-48-like enzymes] (Pitout, 2012). Since the late 1990s, CTX-M types of ESBL enzymes have emerged worldwide among E. coli, and have become the most widespread type of ESBL in the world . A new type of MBL, named NDM, has been described in Klebsiella pneumoniae and E. coli recovered from a Swedish patient who was previously hospitalized in New Delhi, India (Yong et al., 2009). Recent reports from the Indian subcontinent (including India, Pakistan and Bangladesh) show that the distribution of NDM b-lactamases among Enterobacteriaceae is widespread in these countries, while sporadic cases of infections due to bacteria with these enzymes have been reported from different parts of the world, including several countries in Europe, North America, the Middle East, Asia, Africa and Australia (Nordmann et al., 2011).Multilocus sequence typing (MLST), which uses sequence variation in a number of housekeeping gen...

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Section: Resultsmentioning

confidence: 91%

Virulence potential and adherence properties of Escherichia coli that produce CTX-M and NDM β-lactamases

Peirano

Mulvey

Armstrong

et al. 2013

Journal of Medical Microbiology

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“…Avian pathogenic E. coli have been found to commonly possess plasmids containing virulence and ARGs (Dobrindt, 2005;Johnson et al, 2002a;Johnson et al, 2007;Rodriguez-Siek et al, 2005a), in particular ColV and ColBM conjugative plasmids (Dias da Silveira et al, 2002;Johnson and Nolan, 2009;Mellata et al, 2003). The ColV plasmid and pTJ100 and their associated VGs are widely distributed among APEC isolates in comparison to AFEC (Johnson et al, 2002a;Mellata et al, 2003;Rodriguez-Siek et al, 2005a).…”

Section: Plasmid Related Vgsmentioning

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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“…Genomics offers a good tool for defining virulence factors as it can be used to recognize genes encoding for specific factors that contributes to virulence of pathogens. However, the presence of one factor rarely makes an organism virulent; a combination of different factors will determine if an organism can cause infection (Dobrindt, 2005).…”

Section: Introductionmentioning

confidence: 99%

Comparative study on prevalence and association of some virulence factors with extended spectrum beta-lactamases and AmpC producing Escherichia coli

Abdelmegeed¹,

Barwa²,

Galil³

2015

Afr. J. Microbiol. Res.

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The aim of this study was to gain further insight into the interplay between both extended spectrum β-lactamase (ESBL) and AmpC enzymes and different virulence factors (VFs) among Escherichia coli (E. coli) isolated from Mansoura University Hospitals, Egypt. For this purpose 100 E. coli isolates were collected from different clinical sources. All isolates were investigated for production of ESBL and AmpC enzymes. The prevalence of VF encoding genes including: KPsMII (group2 capsule synthesis), FyuA (ferric yersiniabactin uptake), Afa/dra (Dr-binding a fimbrial adhesins), PapA (P fimbriae), PapC (formation of digalactoside-binding Pap pili), iutA (aerobactin receptor) and BssS (biofilm formation) and associations of these genes with both enzyme types were analyzed by polymerase chain reaction. ESBL was produced by 37% of the isolates while AmpC enzyme was produced by 29%. Virulence genes prevalence among ESBL phenotypes were 43.2% KPsMII, 51.35% FyuA, 62.1% Afa/dra, 43.2% PapA, 16.2% PapC, 67.56% iutA and 78.4% BssS. Regarding AmpC phenotypes, the prevalence of virulence genes were: 51.7% KPsMII, 86.2% FyuA, 68.96% Afa/dra, 55.17% PapA, 24.1% PapC, 82.7% iutA and 100% BssS. Of the tested virulence factor encoding genes, BssS, FyuA and iutA were significantly more prevalent among AmpC producers. In addition, AmpC producers exhibited a statistically significant higher prevalence of multivirulence (MV) (MV≥4) than ESBL producers. Furthermore, AmpC phenotypes showed very significantly higher expression (P>0.01) of BssS gene than ESBLs phenotypes. Our results suggest a correlation between AmpC phenotypes and production of some factors that are reported to be involved in the virulence of E. coli.

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(Patho-)Genomics of Escherichia coli

Cited by 144 publications

References 103 publications

Virulence potential and adherence properties of Escherichia coli that produce CTX-M and NDM β-lactamases

Virulence potential and adherence properties of Escherichia coli that produce CTX-M and NDM β-lactamases

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

Comparative study on prevalence and association of some virulence factors with extended spectrum beta-lactamases and AmpC producing Escherichia coli

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