Bacteriophage 2851 Is a Prototype Phage for Dissemination of the Shiga Toxin Variant Gene 2c in
            <i>Escherichia coli</i>
            O157:H7

Strauch, Eckhard; Hammerl, Jens A.; Konietzny, Antje; Schneiker-Bekel, Susanne; Arnold, Walter; Goesmann, Alexander; Pühler, Alfred; Beutin, Lothar

doi:10.1128/iai.00875-08

Cited by 52 publications

(52 citation statements)

References 55 publications

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“…It differs from the prototypical Stx2a-encoding phages BP-933W in its chromosomal integration site, phage morphology, and superinfection immunity (43,44). The Stx2c prophage found in lineage I/II strains (i.e., EC4115) have gene content and architecture similar to phage 2851 (23).…”

Section: Discussionmentioning

confidence: 99%

Evolution of the Stx2-Encoding Prophage in Persistent Bovine Escherichia coli O157:H7 Strains

Park

Stanton

Ciezki

et al. 2013

Appl Environ Microbiol

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e Escherichia coli O157:H7 is a human pathogen that resides asymptomatically in its bovine host. The level of Shiga toxin (Stx) produced is variable in bovine-derived strains in contrast to human isolates that mostly produce high levels of Stx. To understand the genetic basis for varied Stx production, chronological collections of bovine isolates from Wisconsin dairy farms, R and X, were analyzed for multilocus prophage polymorphisms, stx 2 subtypes, and the levels of stx 2 transcript and toxin. The E. coli O157:H7 that persisted on both farms were phylogenetically distinct and yet produced little to no Stx2 due to gene deletions in Stx2c-encoding prophage (farm R) or insertional inactivation of stx 2a by IS1203v (farm X). Loss of key regulatory and lysis genes in Stx2c-encoding prophage abolished stx 2c transcription and induction of the prophage and stx 2a ::IS1203v in Stx2a-encoding prophage generated a truncated stx 2a mRNA without affecting phage production. Stx2-producing strains were transiently present (farm R) and became Stx2 negative on farm X (i.e., stx 2a ::IS1203v). To our knowledge, this is the first study that details the evolution of E. coli O157:H7 and its Stx2-encoding prophage in a chronological collection of natural isolates. The data suggest the bovine and farm environments can be niches where Stx2-negative E. coli O157:H7 emerge and persist, which explains the Stx variability in bovine isolates and may be part of an evolutionary step toward becoming bovine specialists.

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Section: Discussionmentioning

confidence: 99%

Evolution of the Stx2-Encoding Prophage in Persistent Bovine Escherichia coli O157:H7 Strains

Park

Stanton

Ciezki

et al. 2013

Appl Environ Microbiol

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“…Otherwise, this amplicon was recovered in only one sample of effluent treated by PAA (1/4 or 25%), thus underscoring the possible activity of this disinfectant in reducing the potential health hazard associated with the presence of the stx genes. In fact, the stx1/stx2 genes are widely distributed among E. coli (Shiga-toxin-producing E. coli or verotoxin-producing E. coli) and Shigella strains and among other waterborne bacteria because of their dissemination via bacteriophages [25,26]. However, the presence of stx genes is essential but not sufficient to cause infection because other major virulence factors (e.g., the eae gene) could play an important role [27].…”

Section: Salmonella E Coli O157:h7 Campylobactermentioning

confidence: 99%

Peracetic Acid (PAA) Disinfection: Inactivation of Microbial Indicators and Pathogenic Bacteria in a Municipal Wastewater Plant

Bonetta¹,

Pignata²,

Lorenzi

et al. 2017

Water

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Abstract:Several studies have noted that treated and untreated wastewaters are primary contributors of a variety of pathogenic microorganisms to the aquatic ecosystem. Conventional wastewater treatment may not be sufficient to achieve microbiologically safe effluent to be discharged into natural waters or reused, thus requiring wastewater effluents to be disinfected. In recent years, peracetic acid (PAA) has been adopted as a disinfectant for wastewater effluents. The aim of this study was to evaluate the disinfection efficiency of PAA at low doses (range 0.99-2.10 mg/L) against microbial indicators and pathogenic bacteria in a municipal wastewater plant. Samples of untreated sewage and effluents before and after PAA treatment were collected seasonally for 1 year and were analysed for pathogenic Campylobacter, Salmonella spp., E. coli O157:H7 and E. coli virulence genes using molecular methods; moreover, the detection of specific microbial indicators (E. coli, faecal coliforms, enterococci, C. perfringens) and Salmonella spp. were carried out using culturing methods. Salmonella spp. DNA was found in all untreated sewage and effluent before PAA treatment, whereas it was recovered in 50% of the samples collected after PAA treatment. Although E. coli O157:H7 was never identified, the occurrence of Shiga-like toxin I amplicons was identified in 75% of the untreated sewage samples, in 50% of the effluents assayed before PAA treatment, and in 25% of the effluents assayed after PAA treatment, whereas the stx2 gene was never found. Campylobacter coli was only detected in one effluent sample before PAA treatment. In the effluents after PAA treatment, a lower load of indicator bacteria was observed compared to the effluents before treatment. The results of this study highlight that the use of low doses of PAA seems to lead to an improvement of the microbiological quality of the effluent, although it is not sufficient to guarantee its suitability for irrigation. These results underscore the need for additional studies to further assess the efficiency of PAA disinfection in municipal wastewater plants.

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“…All experiments were performed with the LightCycler 480 Real-Time PCR System (Roche), using cDNA samples from lysogenic bacteria. Steady-state levels of transcripts of W24 B , 933W and l genes were compared in parallel to the 16S rRNA, according to a procedure described by Strauch et al, (2008), and it was found to be stable. Primers, presented in Table 3, were developed by Primer3web (version 4) and produced by Sigma Aldrich or GENOMED.…”

Section: Methodsmentioning

confidence: 99%

Defects in RNA polyadenylation impair both lysogenization by and lytic development of Shiga toxin-converting bacteriophages

Nowicki

Bloch

Nejman-Faleńczyk

et al. 2015

Journal of General Virology

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In Escherichia coli, the major poly(A) polymerase (PAP I) is encoded by the pcnB gene. In this report, a significant impairment of lysogenization by Shiga toxin-converting (Stx) bacteriophages (W24 B , 933W, P22, P27 and P32) is demonstrated in host cells with a mutant pcnB gene. Moreover, lytic development of these phages after both infection and prophage induction was significantly less efficient in the pcnB mutant than in the WT host. The increase in DNA accumulation of the Stx phages was lower under conditions of defective RNA polyadenylation. Although shortly after prophage induction, the levels of mRNAs of most phage-borne early genes were higher in the pcnB mutant, at subsequent phases of the lytic development, a drastically decreased abundance of certain mRNAs, including those derived from the N, O and Q genes, was observed in PAP I-deficient cells. All of these effects observed in the pcnB cells were significantly more strongly pronounced in the Stx phages than in bacteriophage l. Abundance of mRNA derived from the pcnB gene was drastically increased shortly (20 min) after prophage induction by mitomycin C and decreased after the next 20 min, while no such changes were observed in non-lysogenic cells treated with this antibiotic. This prophage induction-dependent transient increase in pcnB transcript may explain the polyadenylation-driven regulation of phage gene expression.

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Bacteriophage 2851 Is a Prototype Phage for Dissemination of the Shiga Toxin Variant Gene 2c in Escherichia coli O157:H7

Cited by 52 publications

References 55 publications

Evolution of the Stx2-Encoding Prophage in Persistent Bovine Escherichia coli O157:H7 Strains

Evolution of the Stx2-Encoding Prophage in Persistent Bovine Escherichia coli O157:H7 Strains

Peracetic Acid (PAA) Disinfection: Inactivation of Microbial Indicators and Pathogenic Bacteria in a Municipal Wastewater Plant

Defects in RNA polyadenylation impair both lysogenization by and lytic development of Shiga toxin-converting bacteriophages

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