P fimbriae, capsule and aerobactin characterize colonic resident <i>Escherichia coli</i>

Nowrouzian, Forough L.; Adlerberth, Ingegerd; Wold, Agnes E.

doi:10.1017/s0950268801005118

Cited by 72 publications

(95 citation statements)

References 40 publications

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“…Isolates with an identical pattern were designated the same pulsed-field type, while isolates with up to three fragment differences were defined as subtypes. virulence traits was performed by PCR using primers as described recently (Nowrouzian et al, 2001). The following adhesins were investigated: P fimbriae (presence of papC), S fimbriae (sfaD, sfaE) and Dr haemagglutinin (draA).…”

Section: Methodsmentioning

confidence: 99%

Expression of cellulose and curli fimbriae by Escherichia coli isolated from the gastrointestinal tract

Bokranz

Xiao-da

Tschäpe

et al. 2005

Journal of Medical Microbiology

228

235

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Escherichia coli colonizes the gastrointestinal tract of humans; however, little is known about the features of commensal strains. This study investigated whether expression of the biofilm extracellular matrix components cellulose and curli fimbriae is found among commensal isolates. Fifty-two E. coli strains were isolated from faecal samples and, as a control, 24 strains from urinary tract infections were also used. Faecal isolates were characterized by serotyping and phylogenetically grouped by PCR. The genotype was determined by PFGE and the presence of virulence factors was assessed. Co-expression of cellulose and curli fimbriae at 28 8C and 37 8C was typical for faecal isolates, while urinary tract infection strains typically expressed the extracellular matrix components at 28 8C only. Knockout studies in a representative faecal isolate revealed that the response regulator CsgD regulated cellulose and curli fimbriae, as found previously in Salmonella enterica. In contrast to S. enterica, at 37 8C pellicle formation occurred in the absence of cellulose and curli fimbriae. The gastrointestinal tract represents a source of biofilm-forming bacteria, which can spread to susceptible sites.

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Section: Methodsmentioning

confidence: 99%

Expression of cellulose and curli fimbriae by Escherichia coli isolated from the gastrointestinal tract

Bokranz

Xiao-da

Tschäpe

et al. 2005

Journal of Medical Microbiology

228

235

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“…The 29 selected ST131 isolates were screened by PCR for 53 ExPEC-associated virulence genes and variants (17,20,26,35,47). Virulence scores were the numbers of virulence genes detected for each isolate.…”

Section: Bacterial Isolatesmentioning

confidence: 99%

Commonality among Fluoroquinolone-Resistant Sequence Type ST131 Extraintestinal Escherichia coli Isolates from Humans and Companion Animals in Australia

Platell

Cobbold

Johnson

et al. 2011

Antimicrob Agents Chemother

112

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Escherichia coli sequence type 131 (ST131), an emergent multidrug-resistant extraintestinal pathogen, has spread epidemically among humans and was recently isolated from companion animals. To assess for humancompanion animal commonality among ST131 isolates, 214 fluoroquinolone-resistant extraintestinal E. coli isolates (205 from humans, 9 from companion animals) from diagnostic laboratories in Australia, provisionally identified as ST131 by PCR, selectively underwent PCR-based O typing and bla CTX-M-15 detection. A subset then underwent multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE) analysis, extended virulence genotyping, antimicrobial susceptibility testing, and fluoroquinolone resistance genotyping. All isolates were O25b positive, except for two O16 isolates and one O157 isolate, which (along with six O25b-positive isolates) were confirmed by MLST to be ST131. Only 12% of isolates (25 human, 1 canine) exhibited bla CTX-M-15 . PFGE analysis of 20 randomly selected human and all 9 companion animal isolates showed multiple instances of >94% profile similarity across host species; 12 isolates (6 human, 6 companion animal) represented pulsotype 968, the most prevalent ST131 pulsotype in North America (representing 23% of a large ST131 reference collection). Virulence gene and antimicrobial resistance profiles differed minimally, without host species specificity. The analyzed ST131 isolates also exhibited a conserved, host species-independent pattern of chromosomal fluoroquinolone resistance mutations. However, eight (89%) companion animal isolates, versus two (10%) human isolates, possessed the plasmid-borne qnrB gene (P < 0.001). This extensive across-species strain commonality, plus the similarities between Australian and non-Australian ST131 isolates, suggest that ST131 isolates are exchanged between humans and companion animals both within Australia and intercontinentally.

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“…VFs promote persistence at sites of infection or in the intestinal tract (Nowrouzian et al, 2001(Nowrouzian et al, , 2003, resulting in prolonged exposure to other microbes and consequently increased adaptation to their products. A higher insensitivity could also be regarded as an additional fitness factor, enabling pathogenic strains to persist successfully in a competitive environment.…”

Section: Colicin Insensitivity and Vfsmentioning

confidence: 99%

Colicin insensitivity correlates with a higher prevalence of extraintestinal virulence factors among Escherichia coli isolates from skin and soft-tissue infections

Petkovšek

Žgur-Bertok

Erjavec

2012

Journal of Medical Microbiology

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Colicins are toxic proteins with a narrow killing spectrum that are produced by colicinogenic Escherichia coli strains. The aim of this study was to analyse systematically whether extraintestinal virulence potential is linked to colicin (in)sensitivity. In total, 102 well-characterized E. coli isolates from skin and soft-tissue infections (SSTIs) were exposed to 17 single-colicinproducing strains, and the correlation between insensitivity to colicin and phylogenetic group as well as the extra-intestinal virulence potential of the SSTI strains was examined. The results showed that SSTI strains belonging to the B2 phylogenetic group were statistically significantly associated with insensitivity to at least ten colicins, and several colicin insensitivities were correlated with virulence factors. As far as is known, this is the first study to report such correlations. INTRODUCTIONEscherichia coli is a diverse bacterial species found naturally in the intestinal tract of humans and many other animal species. However, some strains are pathogenic and cause a wide variety of different intestinal as well as extra-intestinal diseases (Marrs et al., 2005). Extra-intestinal pathogenic E. coli (ExPEC) isolates are a medically significant group of pathogens responsible for significant morbidity, mortality and cost to the healthcare system as a result of urinary tract infections (UTIs), diverse intra-abdominal infections, pneumonia, surgical-site infections, meningitis, osteomyelitis, skin and soft-tissue infections (SSTIs) and bacteraemia (Russo & Johnson, 2006). As the causative agent of~90 % of all UTIs among ambulatory female patients (Johnson & Stamm, 1989), it is not surprising that the UTI subgroup of ExPEC has been studied the most extensively. Among SSTIs, E. coli is the third most prevalent species isolated (Moet et al., 2007). Nevertheless, strains from these infections have not been characterized extensively. All ExPEC strains have a common phylogenetic background deriving typically from phylogenetic groups B2 and D, and share the same spectrum of virulence determinants (Russo & Johnson, 2000).Colicins are narrow-killing-spectrum bacteriocins produced by E. coli. Each colicin is unique in its characteristics (see Table 1 for some examples) and they do not share the same killing efficiencies (Feldgarden & Riley, 1998). Whilst it has been shown that colicins prevent the growth of intestinal and uropathogenic E. coli isolates Schamberger et al., 2004; Stahl et al., 2004), a high prevalence of insensitivities to colicins among microbial populations isolated from animals, humans and patients with UTIs has also been reported (Feldgarden & Riley, 1998;Rijavec, 2010;Riley & Gordon, 1992). To our knowledge, the correlation between colicin insensitivity and virulence potential has not yet been investigated. Therefore, the prevalence of colicin insensitivity among E. coli SSTI isolates with known virulence potential was determined systematically by exposing 102 strains to 17 different colicins. Furthermore, for the first time,...

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P fimbriae, capsule and aerobactin characterize colonic resident Escherichia coli

Cited by 72 publications

References 40 publications

Expression of cellulose and curli fimbriae by Escherichia coli isolated from the gastrointestinal tract

Expression of cellulose and curli fimbriae by Escherichia coli isolated from the gastrointestinal tract

Commonality among Fluoroquinolone-Resistant Sequence Type ST131 Extraintestinal Escherichia coli Isolates from Humans and Companion Animals in Australia

Colicin insensitivity correlates with a higher prevalence of extraintestinal virulence factors among Escherichia coli isolates from skin and soft-tissue infections

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