Comparable stx 2a expression and phage production levels between Shiga toxin‐producing Escherichia coli strains from human and bovine origin

2019 ◽  
Vol 67 (1) ◽  
pp. 44-53 ◽  
Author(s):  
Julia Burgán ◽  
Alejandra Krüger ◽  
Paula M. A. Lucchesi
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Phage Production

Diversity of stx 2 converting bacteriophages induced from Shiga-toxin-producing Escherichia coli strains isolated from cattle

Microbiology ◽  
2004 ◽  
Vol 150 (9) ◽  
pp. 2959-2971 ◽  
Author(s):  
Maite Muniesa ◽  
Jesus E. Blanco ◽  
Merce de Simón ◽  
Ruth Serra-Moreno ◽  
Anicet R. Blanch ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Toxin Production ◽  
Animal Origin ◽  
Phage Dna ◽  
Wide Variability ◽  
Shiga Toxin 2 ◽  
Phage Production ◽  
Different Strains ◽  
Host Strains

The presence of bacteriophages encoding Shiga toxin 2 (stx 2 phages) was analysed in 168 strains of Shiga-toxin-producing Escherichia coli (STEC) isolated from cattle. Following mitomycin C induction, strains carrying stx 2 phages were screened by plaque blot and hybridization with an stx 2 A-probe. In the stx 2-phage-carrying strains, the amounts of phage production, phage DNA extracted and Stx2 produced after induction were assessed. The induced stx 2 phages were characterized morphologically and genetically. Assays to obtain lysogens from different strains were also carried out and phages induced from the lysogens were compared with those induced from the STEC isolates. Results indicated that 18 % of the strains carried an inducible stx 2 phage. Most of them showed a direct relationship between phage induction and toxin production. Each strain carried only one inducible stx 2 phage, although a few strains had two copies of the stx 2 in the chromosome. The stx 2 phages showed diverse morphology and a wide variability in their genome. Assays to obtain lysogens showed that not all the phages were transduced with the same frequency and only six lysogens were obtained. Phages in the lysogens were the same as those induced from their respective initial STEC host strains, although the induction and relative toxin production of the lysogens varied. Most phages carried the stx 2 gene, while a few carried stx 2 variants. Infectivity of the phages depended on the different hosts, although O157 : H7 was preferentially infected by phages induced from O157 strains. The results show that inducible stx 2 phages are common among STEC of animal origin and that they may enhance the spread of stx 2.

scholarly journals Shiga Toxin 2-Converting Bacteriophages Associated with Clonal Variability in Escherichia coli O157:H7 Strains of Human Origin Isolated from a Single Outbreak

2003 ◽  
Vol 71 (8) ◽  
pp. 4554-4562 ◽  
Author(s):  
Maite Muniesa ◽  
Mercè de Simon ◽  
Guillem Prats ◽  
Dolors Ferrer ◽  
Helena Pañella ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Mitomycin C ◽  
Shiga Toxin ◽  
Escherichia Coli O157 ◽  
Human Origin ◽  
Bacterial Isolates ◽  
Recent Outbreak ◽  
Shiga Toxin 2 ◽  
Phage Production ◽  
Clonal Variability

ABSTRACT Shiga toxin 2 (Stx2)-converting bacteriophages induced from 49 strains of Escherichia coli O157:H7 isolated during a recent outbreak of enterocolitis in Spain were examined in an attempt to identify the variability due to the stx 2-converting phages. The bacterial isolates were divided into low-, medium-, and high-phage-production groups on the basis of the number of phages released after mitomycin C induction. Low- and medium-phage-production isolates harbored two kinds of phages but released only one of them, whereas high-phage-production isolates harbored only one of the two phages. One of the phages, φSC370, which was detected only in the isolates with two phages, showed similarities with phage 933W. The second phage, φLC159, differed from φSC370 in morphology and DNA structure. When both phages were present in the same bacterial chromosome, as occurred in most of the isolates, only φSC370 was detected in the supernatants of the induced cultures. If φLC159 was released, its presence was masked by φSC370. When φSC370 was absent, large amounts of φLC159 were released, suggesting that there was some regulation of phage expression between the two phages. To our knowledge, this is the first description of clonal variability due to phage loss. The higher level of phage production was reflected in the larger amounts of Stx2 toxin produced by the cultures. Some relationship between phage production and the severity of symptoms was observed, and consequently these observations suggest that the virulence of the isolates studied could be related to the variability of the induced stx 2-converting phages.

Impact of Antibiotics on the Intestinal Microbiota and on the Treatment of Shiga-toxin-Producing Escherichia coli and Salmonella Infections

2014 ◽  
Vol 20 (28) ◽  
pp. 4535-4548 ◽  
Author(s):  
Jolanta Szych ◽  
Tomasz Wo.lkowicz ◽  
Roberto Ragione ◽  
Grzegorz Madajczak
Keyword(s):  
Escherichia Coli ◽  
Intestinal Microbiota ◽  
Shiga Toxin ◽  
Salmonella Infections

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.

scholarly journals Epigenetic Regulation of Gene Expression in Shiga Toxin-Producing Escherichia coli: Transcriptomic Data

Data in Brief ◽  
2021 ◽  
pp. 107065
Author(s):  
Michelle Qiu Carter ◽  
Bin Hu ◽  
Patrick S G Chain
Keyword(s):  
Gene Expression ◽  
Escherichia Coli ◽  
Epigenetic Regulation ◽  
Shiga Toxin ◽  
Regulation Of Gene Expression ◽  
Transcriptomic Data

scholarly journals Evaluation of PMA‐qPCR methodology to detect and quantify viable Shiga toxin‐producing Escherichia coli in beef burgers

2021 ◽  
Vol 45 (4) ◽  
Author(s):  
María de los Ángeles Rey ◽  
Mariana Cap ◽  
Leonardo Cristian Favre ◽  
Anabel Rodríguez Racca ◽  
María José Dus Santos ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Beef Burgers
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