Detection of Escherichia coli serogroup O103 by real-time polymerase chain reaction

Perelle, Sylvie; Dilasser, Françoise; Grout, Joël; Fach, Patrick

doi:10.1111/j.1365-2672.2005.02545.x

Cited by 63 publications

(38 citation statements)

References 37 publications

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“…A second screening step was performed on stx-and eae-positive samples for the detection of the five O group markers. This second step included two simplex real-time PCR assays to detect rfbE O157 and wbd1 O111 genes and one triplex real-time PCR assay for the screening of wzx O26 , wzx O103 , and ihp1 O145 genes, with primers and probes described elsewhere (30,31). All the PCR experiments were performed using a CFX96 instrument (Bio-Rad), except those targeting eae subtypes, which were performed on a LightCycler 480 instrument (Roche Diagnostics).…”

Section: Methodsmentioning

confidence: 99%

Prevalence of Carriage of Shiga Toxin-Producing Escherichia coli Serotypes O157:H7, O26:H11, O103:H2, O111:H8, and O145:H28 among Slaughtered Adult Cattle in France

Bibbal

Loukiadis

Kérourédan

et al. 2015

Appl Environ Microbiol

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The main pathogenic enterohemorrhagic Escherichia coli (EHEC) strains are defined as Shiga toxin (Stx)-producing E. coli (STEC) belonging to one of the following serotypes: O157:H7, O26:H11, O103:H2, O111:H8, and O145:H28. Each of these five serotypes is known to be associated with a specific subtype of the intimin-encoding gene (eae). The objective of this study was to evaluate the prevalence of bovine carriers of these "top five" STEC in the four adult cattle categories slaughtered in France. Fecal samples were collected from 1,318 cattle, including 291 young dairy bulls, 296 young beef bulls, 337 dairy cows, and 394 beef cows. A total of 96 E. coli isolates, including 33 top five STEC and 63 atypical enteropathogenic E. coli (aEPEC) isolates, with the same genetic characteristics as the top five STEC strains except that they lacked an stx gene, were recovered from these samples. O157:H7 was the most frequently isolated STEC serotype. The prevalence of top five STEC (all serotypes included) was 4.5% in young dairy bulls, 2.4% in young beef bulls, 1.8% in dairy cows, and 1.0% in beef cows. It was significantly higher in young dairy bulls (P < 0.05) than in the other 3 categories. The basis for these differences between categories remains to be elucidated. Moreover, simultaneous carriage of STEC O26:H11 and STEC O103:H2 was detected in one young dairy bull. Lastly, the prevalence of bovine carriers of the top five STEC, evaluated through a weighted arithmetic mean of the prevalence by categories, was estimated to 1.8% in slaughtered adult cattle in France.

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Section: Methodsmentioning

confidence: 99%

Prevalence of Carriage of Shiga Toxin-Producing Escherichia coli Serotypes O157:H7, O26:H11, O103:H2, O111:H8, and O145:H28 among Slaughtered Adult Cattle in France

Bibbal

Loukiadis

Kérourédan

et al. 2015

Appl Environ Microbiol

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“…These methods were not capable of molecular serotyping (e.g., espZ-␤1 does not exclusively correlate to O26:H11 strains) and do not provide additional discrimination of STEC isolates compared to typing of the eae locus, but genotyping of toxin and pathogenicity islands can be used to infer different STEC lineages. Previously developed detection methods for O serotypes have been developed using targets from the O-antigen cluster genes wzx and wzy carried by EHEC O157, O103, O26, and O113 serotypes (5,11,26), and examination of additional loci, including the genes described here, or of genes unique to individual serotypes such as fimbria-encoding determinants (31, 34) may cumulatively provide a means for molecular serotyping.…”

Section: Discussionmentioning

confidence: 99%

Use of the espZ Gene Encoded in the Locus of Enterocyte Effacement for Molecular Typing of Shiga Toxin-Producing Escherichia coli

et al. 2006

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Infections with Shiga toxin-producing Escherichia coli (STEC) result in frequent cases of sporadic and outbreak-associated enteric bacterial disease in humans. Classification of STEC is by stx genotype (encoding the Shiga toxins), O and H antigen serotype, and seropathotype (subgroupings based upon the clinical relevance and virulence-related genotypes of individual serotypes). The espZ gene is encoded in the locus of enterocyte effacement (LEE) pathogenicity island responsible for the attaching and effacing (A/E) lesions caused by various E. coli pathogens (but not limited to STEC), and this individual gene (ϳ300 bp) has previously been identified as hypervariable among these A/E pathogens. Sequence analysis of the espZ locus encoded by additional STEC serotypes and strains (including O26:H11, O121:H19, O111:NM, O145:NM, O165:H25, O121:NM, O157:NM, O157:H7, and O5:NM) indicated that distinct sequence variants exist which correlate to subgroups among these serotypes. Allelic discrimination at the espZ locus was achieved using Light Upon eXtension real-time PCR and by liquid microsphere suspension arrays. The allele subtype of espZ did not correlate with STEC seropathotype classification; however, a correlation with the allele type of the LEEencoded intimin (eae) gene was supported, and these sequence variations were conserved among individual serotypes. The study focused on the characterization of three clinically significant seropathotypes of LEEpositive STEC, and we have used the observed genetic variation at a pathogen-specific locus for detection and subtyping of STEC.

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“…Multiplex PCR was used to detect genes encoding verocytotoxin types (vtx 1 , vtx 2 ), intimin (eae) and enterohaemolysin (hlyA) and also O group-specific genes (Paton & Paton, 1998;Perelle et al, 2004Perelle et al, , 2005. The PCR mixes were prepared and the cycling and subsequent electrophoresis conditions were those described by Paton & Paton (1998).…”

Section: Methodsmentioning

confidence: 99%

Prevalence of Escherichia coli O157 : H7 and serogroups O26, O103, O111 and O145 in sheep presented for slaughter in Scotland

Evans

Knight

McKendrick

et al. 2011

Journal of Medical Microbiology

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Sheep have been proposed as a source of human verocytotoxigenic Escherichia coli infection on a number of occasions but few prevalence studies have focused on identifying rates of carriage of these pathogens in this species. The purpose of this work was to establish the frequency of excretion of E. coli of serogroups O157, O26, O103, O111 and O145 in sheep presented for slaughter in Scotland and to examine their carriage of known virulence determinants. The study involved microbiological isolation of E. coli from 1082 sheep presented for slaughter in four Scottish abattoirs between July 2005 and June 2006. Using faecal enrichment and immunomagnetic separation, the isolation rate from these samples was 3.4 % for E. coli serogroup O157, 5.2 % for E. coli serogroup O26, 2.3 % for E. coli serogroup O103 and 0.1 % for E. coli serogroup O145. E. coli O111 was not isolated. In the last month of testing, which coincided with sorbitol-fermenting E. coli O157 (SFO157) cases in children in Scotland, all 83 recta received were screened and tested negative for SFO157 strains. The study found no verocytotoxin-positive strains amongst the E. coli serogroup O103 or O145 isolates. Verocytotoxin-positive strains were identified amongst isolates of E. coli serotypes O157 : H7 and O26 : H11. E. coli O157 : H7 was not isolated from samples collected between January and March, a statistically significant drop (P,0.001) in mean shedding relative to other months. There was evidence (P50.003) of higher shedding of O157 in adults and hoggs than in lambs. E. coli O26 : H11 was isolated throughout the year, with a statistically significant peak in shedding in the third quarter (P50.003). The results showed that sheep presented for slaughter in Scotland may carry strains of E. coli, particularly of serogroups O157 and O26, which can be presumed to have potential to cause human infection. They did not support a hypothesis that human cases of E. coli O157 : H7 are higher in any particular Scottish region as a direct consequence of a higher rate of faecal carriage in sheep in that region. INTRODUCTIONEscherichia coli strains that produce verocytotoxins are important pathogens causing human illnesses ranging from diarrhoea to haemorrhagic colitis and haemolytic uraemic syndrome (Karmali, 1989;Riley, 1987). In the UK, North America, Japan and much of continental Europe, such disease is commonly caused by E. coli strains of serogroup O157 (Riley et al., 1983;Kleanthous et al., 1990;Willshaw et al., 2001;Kaper et al., 2004;Chase-Topping et al., 2008).A variety of infection routes, including food-borne transmission and person-to-person spread, have been described, but in the UK, human infections by E. coli O157 are also recognized arising from direct contact with animal reservoirs (Locking et al., 2001;O'Brien et al., 2001). Examples of where infection has been specifically associated with sheep include: illness linked with lambing ewes (Allison et al., 1997); sheep faeces apparently contaminating the water supply at a campsite outbreak (Licence et...

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Detection of Escherichia coli serogroup O103 by real-time polymerase chain reaction

Cited by 63 publications

References 37 publications

Prevalence of Carriage of Shiga Toxin-Producing Escherichia coli Serotypes O157:H7, O26:H11, O103:H2, O111:H8, and O145:H28 among Slaughtered Adult Cattle in France

Prevalence of Carriage of Shiga Toxin-Producing Escherichia coli Serotypes O157:H7, O26:H11, O103:H2, O111:H8, and O145:H28 among Slaughtered Adult Cattle in France

Use of the espZ Gene Encoded in the Locus of Enterocyte Effacement for Molecular Typing of Shiga Toxin-Producing Escherichia coli

Prevalence of Escherichia coli O157 : H7 and serogroups O26, O103, O111 and O145 in sheep presented for slaughter in Scotland

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