DNA sequence and analysis of a 90.1-kb plasmid in Shiga toxin-producing Escherichia coli (STEC) O145:NM 83-75

Plasmid ◽  
2012 ◽  
Vol 68 (1) ◽  
pp. 25-32 ◽  
Author(s):  
Xianghe Yan ◽  
Pina M. Fratamico ◽  
David S. Needleman ◽  
Darrell O. Bayles
Keyword(s):  
Escherichia Coli ◽  
Dna Sequence ◽  
Shiga Toxin

scholarly journals Association of Nucleotide Polymorphisms within the O-Antigen Gene Cluster of Escherichia coli O26, O45, O103, O111, O121, and O145 with Serogroups and Genetic Subtypes

2012 ◽  
Vol 78 (18) ◽  
pp. 6689-6703 ◽  
Author(s):  
Keri N. Norman ◽  
Nancy A. Strockbine ◽  
James L. Bono
Keyword(s):  
Escherichia Coli ◽  
Gene Cluster ◽  
Dna Sequence ◽  
Shiga Toxin ◽  
Severe Disease ◽  
The United States ◽  
Effective Control ◽  
Nucleotide Polymorphisms ◽  
Antigen Gene ◽  
O Antigen

ABSTRACTShiga toxin-producingEscherichia coli(STEC) strains are important food-borne pathogens capable of causing hemolytic-uremic syndrome. STEC O157:H7 strains cause the majority of severe disease in the United States; however, there is a growing concern for the amount and severity of illness attributable to non-O157 STEC. Recently, the Food Safety and Inspection Service (FSIS) published the intent to regulate the presence of STEC belonging to serogroups O26, O45, O103, O111, O121, and O145 in nonintact beef products. To ensure the effective control of these bacteria, sensitive and specific tests for their detection will be needed. In this study, we identified single nucleotide polymorphisms (SNPs) in the O-antigen gene cluster that could be used to detect STEC strains of the above-described serogroups. Using comparative DNA sequence analysis, we identified 22 potentially informative SNPs among 164 STEC and non-STEC strains of the above-described serogroups and designed matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF) assays to test the STEC allele frequencies in an independent panel of bacterial strains. We found at least one SNP that was specific to each serogroup and also differentiated between STEC and non-STEC strains. Differences in the DNA sequence of the O-antigen gene cluster corresponded well with differences in the virulence gene profiles and provided evidence of different lineages for STEC and non-STEC strains. The SNPs discovered in this study can be used to develop tests that will not only accurately identify O26, O45, O103, O111, O121, and O145 strains but also predict whether strains detected in the above-described serogroups contain Shiga toxin-encoding genes.

The complete DNA sequence and analysis of the virulence plasmid and of five additional plasmids carried by Shiga toxin-producing Escherichia coli O26:H11 strain H30☆

2011 ◽  
Vol 301 (3) ◽  
pp. 192-203 ◽  
Author(s):  
Pina M. Fratamico ◽  
Xianghe Yan ◽  
Alfredo Caprioli ◽  
Giuseppina Esposito ◽  
David S. Needleman ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Dna Sequence ◽  
Shiga Toxin ◽  
Virulence Plasmid

scholarly journals Molecular Analysis of Cytolysin A (ClyA) in Pathogenic Escherichia coli Strains

2004 ◽  
Vol 186 (16) ◽  
pp. 5311-5320 ◽  
Author(s):  
Albrecht Ludwig ◽  
Christine von Rhein ◽  
Susanne Bauer ◽  
Christian Hüttinger ◽  
Werner Goebel
Keyword(s):  
Escherichia Coli ◽  
Dna Sequence ◽  
Shiga Toxin ◽  
Transcriptional Regulator ◽  
The Other ◽  
Standard Laboratory ◽  
Sequence Analyses ◽  
E Coli ◽  
Pathogenic Escherichia Coli ◽  
K 12

ABSTRACT Cytolysin A (ClyA) of Escherichia coli is a pore-forming hemolytic protein encoded by the clyA (hlyE, sheA) gene that was first identified in E. coli K-12. In this study we examined various clinical E. coli isolates with regard to the presence and integrity of clyA. PCR and DNA sequence analyses demonstrated that 19 of 23 tested Shiga toxin-producing E. coli (STEC) strains, all 7 tested enteroinvasive E. coli (EIEC) strains, 6 of 8 enteroaggregative E. coli (EAEC) strains, and 4 of 7 tested enterotoxigenic E. coli (ETEC) strains possess a complete clyA gene. The remaining STEC, EAEC, and ETEC strains and 9 of the 17 tested enteropathogenic E. coli (EPEC) strains were shown to harbor mutant clyA derivatives containing 1-bp frameshift mutations that cause premature termination of the coding sequence. The other eight EPEC strains and all tested uropathogenic and new-born meningitis-associated E. coli strains (n = 14 and 3, respectively) carried only nonfunctional clyA fragments due to the deletion of two sequences of 493 bp and 204 or 217 bp at the clyA locus. Expression of clyA from clinical E. coli isolates proved to be positively controlled by the transcriptional regulator SlyA. Several tested E. coli strains harboring a functional clyA gene produced basal amounts of ClyA when grown under standard laboratory conditions, but most of them showed a clyA-dependent hemolytic phenotype only when SlyA was overexpressed. The presented data indicate that cytolysin A can play a role only for some of the pathogenic E. coli strains.

DNA sequence of theEscherichia coliO103 O antigen gene cluster and detection of enterohemorrhagicE. coliO103 by PCR amplification of thewzxandwzygenes

2005 ◽  
Vol 51 (6) ◽  
pp. 515-522 ◽  
Author(s):  
Pina M Fratamico ◽  
Chitrita DebRoy ◽  
Terence P Strobaugh, Jr. ◽  
Chin-Yi Chen
Keyword(s):  
Escherichia Coli ◽  
Real Time ◽  
Gene Cluster ◽  
Dna Sequence ◽  
Shiga Toxin ◽  
E Coli ◽  
Antigen Gene ◽  
O Antigen ◽  
Pcr Assays ◽  
Pcr Targeting

Escherichia coli serogroup O103 has been associated with gastrointestinal illness and hemolytic uremic syndrome. To develop PCR-based methods for detection and identification of this serogroup, the DNA sequence of the 12 033-bp region containing the O antigen gene cluster of Escherichia coli O103 was determined. Of the 12 open reading frames identified, the E. coli O103 wzx (O antigen flippase) and wzy (O antigen polymerase) genes were selected as targets for development of both conventional and real-time PCR assays specific for this serogroup. In addition, a multiplex PCR targeting the Shiga toxin (Stx) 1 (stx1), Shiga toxin 2 (stx2), wzx, and wzy genes was developed to differentiate Stx-producing E. coli O103 from non-toxigenic strains. The PCR assays can be employed to identify E. coli serogroup O103, replacing antigen-based serotyping, and to potentially detect the organism in food, fecal, or environmental samples.Key words: real-time polymerase chain reaction, E. coli typing, E. coli O103, O antigen DNA sequence.

scholarly journals Association of Ct Values from Real-Time PCR with Culture in Microbiological Clearance Samples for Shiga Toxin-Producing Escherichia coli (STEC)

2020 ◽  
Vol 8 (11) ◽  
pp. 1801
Author(s):  
Michael Bording-Jorgensen ◽  
Brendon D. Parsons ◽  
Gillian A.M. Tarr ◽  
Binal Shah-Gandhi ◽  
Colin Lloyd ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Real Time ◽  
Shiga Toxin ◽  
Real Time Pcr ◽  
Gene Detection ◽  
Culture Positivity ◽  
Hands On ◽  
Culture Independent ◽  
Chromogenic Agar ◽  
Stool Samples

Shiga toxin-producing Escherichia coli (STEC) are associated with acute gastroenteritis worldwide, which induces a high economic burden on both healthcare and individuals. Culture-independent diagnostic tests (CIDT) in frontline microbiology laboratories have been implemented in Alberta since 2019. The objectives of this study were to determine the association between gene detection and culture positivity over time using STEC microbiological clearance samples and also to establish the frequency of specimen submission. Both stx genes’ amplification by real-time PCR was performed with DNA extracted from stool samples using the easyMAG system. Stools were inoculated onto chromogenic agar for culture. An association between gene detection and culture positivity was found to be independent of which stx gene was present. CIDT can provide rapid reporting with less hands-on time and technical expertise. However, culture is still important for surveillance and early cluster detection. In addition, stool submissions could be reduced from daily to every 3–5 days until a sample is negative by culture.

scholarly journals Effects of Plant Age and Root Damage on Internalization of Shiga Toxin-Producing Escherichia coli in Leafy Vegetables and Herbs

Horticulturae ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 68
Author(s):  
Yi-Ju Wang ◽  
Amanda J. Deering ◽  
Hye-Ji Kim
Keyword(s):  
Escherichia Coli ◽  
Plant Species ◽  
Shiga Toxin ◽  
Production Systems ◽  
Plant Age ◽  
Leafy Vegetables ◽  
Root Damage ◽  
Hygiene Practices ◽  
Hydroponic Systems ◽  
Stx1 Gene

Our previous study reported that fresh produce grown in aquaponic and hydroponic systems can pose potential food safety hazards due to an accidental introduction of contaminated fish and cross-contamination between the systems. In this study, we examined the effects of plant species and age on the likelihood and level of internalization of Shiga toxin-producing Escherichia coli (STEC) in aquaponic and hydroponic systems. Four plant species, basil (Ocimum basilicum L. cv. Genovese), cilantro (Coriandrum Sativum L.), lettuce (Lactuca sativa cv. Cherokee), and kale (Brassica oleracea var. sabellica), received root damage treatment as seedlings before transplanting or mature plants at three weeks after transplanting by cutting off 1-cm tips of one-third of the roots. Enrichments and selective media were used for the isolation, and presumptive positive colonies were confirmed by PCR for the presence of stx1 gene in plant tissues, recirculating water, and fish feces collected at four weeks after transplanting. In hydroponic systems, STEC was found neither in the solution nor in the roots and leaves of all four plant species, possibly through improved sanitation and hygiene practices. However, consistent with our previous findings, STEC was found in the water, on the plant roots, and in the fish feces in aquaponic systems, even after thorough sanitation prior to the study. Regardless of plant age, STEC was internalized in the roots of all plant species when the roots were damaged, but there was no difference in the degree of internalization with STEC among plant species. STEC was present in the leaves only when seedlings received root damage treatment and were grown to maturity, indicating that root damage allows STEC to internalize in the roots within a week, but a longer period is required for STEC to internalize into the leaves. We concluded that root damage on seedlings can cause the internalization of E. coli O157:H7 in the edible parts of leafy vegetables and herbs in soilless production systems.

Sign in / Sign up

Export Citation Format

Share Document