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Factors Governing the Persistence, Infection, Virulence and Treatment of Shiga...
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Factors Governing the Persistence, Infection, Virulence and Treatment of Shiga Toxin-Encoding E. coli (STEC)

A special issue of Toxins (ISSN 2072-6651). This special issue belongs to the section "Bacterial Toxins".

Deadline for manuscript submissions: closed (30 September 2021) | Viewed by 10089

Special Issue Editor

Prof. Dr. Gerald B. Koudelka

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Guest Editor
Department of Biological Sciences, University at Buffalo, Buffalo, NY 14260, USA
Interests: Evolution, distribution and role of exotoxin-encoding bacteria and phages in the environment; Identification and characterization of bacterial anti-predator defense mechanisms; Biotic and abiotic factors that govern the stability lambdoid prophages; DNA structure effects on protein-DNA Interactions
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Shiga toxins (Stx) are the main virulence factor of a group of Shiga toxin-encoding E. coli (STEC) strains that cause severe human diseases, such as hemorrhagic colitis and hemolytic uremic syndrome. These toxins are encoded by prophages present in all STEC. Stx synthesis and release and therefore STEC-mediated disease require activation of prophage growth. STEC are implicated in over 10,000 cases of human illness annually in the United States alone, and infection with STEC carries a mortality rate as high as 10%. Shiga toxin intoxication is the number one cause of acute renal failure in children. Alarmingly, the incidence of Shiga toxin-related illness is increasing; in the two decades subsequent to its first emergence, outbreaks of disease caused by STEC increased >20-fold. In addition to contaminated food, STEC outbreaks are increasingly associated with environmental contamination of water. Despite the increasing severity and incidence of STEC-mediated disease, and potential susceptibility of STEC to antimicrobial therapy, current guidelines urge that all antibiotics be avoided in life-threatening EHEC infections. Hence, there are no clear treatments for STEC infection.

This Special Issue will focus on both deducing the factors that drive the increasing incidence of STEC infection and providing insight into new prevention and treatment regimes. This issue will include studies of bacterial and phage factors that mediate environmental persistence, increased human infection, increased STEC virulence, and how these factors can be exploited to provide new strategies to combat STEC infection.

Prof. Gerald B. Koudelka
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a double-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Toxins is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Shiga toxin
  • Bacteria
  • Bacteriophage
  • STEC
  • E. coli
  • Virulence
  • Diversity
  • Antibiotics
  • SOS
  • Gene expression
  • Pathogenesis
  • Infection

Published Papers (3 papers)

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Research

15 pages, 2353 KiB  
Article
A Validation System for Selection of Bacteriophages against Shiga Toxin-Producing Escherichia coli Contamination
by Agnieszka Necel, Sylwia Bloch, Bożena Nejman-Faleńczyk, Aleksandra Dydecka, Gracja Topka-Bielecka, Alicja Węgrzyn and Grzegorz Węgrzyn
Toxins 2021, 13(9), 644; https://doi.org/10.3390/toxins13090644 - 11 Sep 2021
Cited by 4 | Viewed by 2503
Abstract
Shiga toxin-producing Escherichia coli (STEC) can cause severe infections in humans, leading to serious diseases and dangerous complications, such as hemolytic-uremic syndrome. Although cattle are a major reservoir of STEC, the most commonly occurring source of human infections are food products (e.g., vegetables) [...] Read more.
Shiga toxin-producing Escherichia coli (STEC) can cause severe infections in humans, leading to serious diseases and dangerous complications, such as hemolytic-uremic syndrome. Although cattle are a major reservoir of STEC, the most commonly occurring source of human infections are food products (e.g., vegetables) contaminated with cow feces (often due to the use of natural fertilizers in agriculture). Since the use of antibiotics against STEC is controversial, other methods for protection of food against contaminations by these bacteria are required. Here, we propose a validation system for selection of bacteriophages against STEC contamination. As a model system, we have employed a STEC-specific bacteriophage vB_Eco4M-7 and the E. coli O157:H7 strain no. 86-24, bearing Shiga toxin-converting prophage ST2-8624 (Δstx2::cat gfp). When these bacteria were administered on the surface of sliced cucumber (as a model vegetable), significant decrease in number viable E. coli cells was observed after 6 h of incubation. No toxicity of vB_Eco4M-7 against mammalian cells (using the Balb/3T3 cell line as a model) was detected. A rapid decrease of optical density of STEC culture was demonstrated following addition of a vB_Eco4M-7 lysate. However, longer incubation of susceptible bacteria with this bacteriophage resulted in the appearance of phage-resistant cells which predominated in the culture after 24 h incubation. Interestingly, efficiency of selection of bacteria resistant to vB_Eco4M-7 was higher at higher multiplicity of infection (MOI); the highest efficiency was evident at MOI 10, while the lowest occurred at MOI 0.001. A similar phenomenon of selection of the phage-resistant bacteria was also observed in the experiment with the STEC-contaminated cucumber after 24 h incubation with phage lysate. On the other hand, bacteriophage vB_Eco4M-7 could efficiently develop in host bacterial cells, giving plaques at similar efficiency of plating at 37, 25 and 12 °C, indicating that it can destroy STEC cells at the range of temperatures commonly used for vegetable short-term storage. These results indicate that bacteriophage vB_Eco4M-7 may be considered for its use in food protection against STEC contamination; however, caution should be taken due to the phenomenon of the appearance of phage-resistant bacteria. Full article
(This article belongs to the Special Issue Factors Governing the Persistence, Infection, Virulence and Treatment of Shiga Toxin-Encoding E. coli (STEC))
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10 pages, 1875 KiB  
Article
Psychoactive Drugs Induce the SOS Response and Shiga Toxin Production in Escherichia coli
by John K. Crane, Mashal Salehi and Cassandra L. Alvarado
Toxins 2021, 13(7), 437; https://doi.org/10.3390/toxins13070437 - 23 Jun 2021
Cited by 6 | Viewed by 2243
Abstract
Several classes of non-antibiotic drugs, including psychoactive drugs, proton-pump inhibitors (PPIs), non-steroidal anti-inflammatory drugs (NSAIDs), and others, appear to have strong antimicrobial properties. We considered whether psychoactive drugs induce the SOS response in E. coli bacteria and, consequently, induce Shiga toxins in Shiga-toxigenic [...] Read more.
Several classes of non-antibiotic drugs, including psychoactive drugs, proton-pump inhibitors (PPIs), non-steroidal anti-inflammatory drugs (NSAIDs), and others, appear to have strong antimicrobial properties. We considered whether psychoactive drugs induce the SOS response in E. coli bacteria and, consequently, induce Shiga toxins in Shiga-toxigenic E. coli (STEC). We measured the induction of an SOS response using a recA-lacZ E. coli reporter strain, as RecA is an early, reliable, and quantifiable marker for activation of the SOS stress response pathway. We also measured the production and release of Shiga toxin 2 (Stx2) from a classic E. coli O157:H7 strain, derived from a food-borne outbreak due to spinach. Some, but not all, serotonin selective reuptake inhibitors (SSRIs) and antipsychotic drugs induced an SOS response. The use of SSRIs is widespread and increasing; thus, the use of these antidepressants could account for some cases of hemolytic-uremic syndrome due to STEC and is not attributable to antibiotic administration. SSRIs could have detrimental effects on the normal intestinal microbiome in humans. In addition, as SSRIs are resistant to environmental breakdown, they could have effects on microbial communities, including aquatic ecosystems, long after they have left the human body. Full article
(This article belongs to the Special Issue Factors Governing the Persistence, Infection, Virulence and Treatment of Shiga Toxin-Encoding E. coli (STEC))
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14 pages, 1733 KiB  
Article
Genes Encoding the Virulence and the Antimicrobial Resistance in Enterotoxigenic and Shiga-toxigenic E. coli Isolated from Diarrheic Calves
by Abdelazeem M. Algammal, Ali W. El-Kholy, Emad M. Riad, Hossam E. Mohamed, Mahmoud M. Elhaig, Sulaiman A. Al Yousef, Wael N. Hozzein and Madeha O. I. Ghobashy
Toxins 2020, 12(6), 383; https://doi.org/10.3390/toxins12060383 - 10 Jun 2020
Cited by 34 | Viewed by 4373
Abstract
Calf diarrhea is one of the considerable infectious diseases in calves, which results in tremendous economic losses globally. To determine the prevalence of Shiga-toxigenic E. coli (STEC) and Enterotoxigenic E. coli (ETEC) incriminated in calf diarrhea, with special reference to Shiga- toxins genes [...] Read more.
Calf diarrhea is one of the considerable infectious diseases in calves, which results in tremendous economic losses globally. To determine the prevalence of Shiga-toxigenic E. coli (STEC) and Enterotoxigenic E. coli (ETEC) incriminated in calf diarrhea, with special reference to Shiga- toxins genes (stx1 and stx2) and enterotoxins genes (lt and sta) that govern their pathogenesis, as well as the virulence genes; eaeA (intimin) and f41(fimbrial adhesion), and the screening of their antibiogram and antimicrobial resistance genes; aadB, sul1, and bla-TEM, a total of 274 fecal samples were collected (April 2018–Feb 2019) from diarrheic calves at different farms in El-Sharqia Governorate, Egypt. The bacteriological examination revealed that the prevalence of E. coli in diarrheic calves was 28.8%. The serotyping of the isolated E. coli revealed 7 serogroups; O26, O128, O111, O125, O45, O119 and O91. Furthermore, the Congo red binding test was carried out, where 89.8% of the examined strains (n = 71) were positive. The antibiogram of the isolated strains was investigated; the majority of E. coli serotypes exhibit multidrug resistance (MDR) to four antimicrobial agents; neomycin, gentamycin, streptomycin, and amikacin. Polymerase chain reaction (PCR) was used to detect the prevalence of the virulence genes; stx1, stx2 lt, sta, f41 and eaeA, as well as the antimicrobial resistance genes; aadB, sul1, and bla-TEM. The prevalence of STEC was 20.2% (n = 16), while the prevalence of ETEC was 30.4% (n = 24). Briefly, the Shiga toxins genes; stx1 and stx2, are the most prevalent virulence genes associated with STEC, which are responsible for the pathogenesis of the disease and helped by the intimin gene (eaeA). In addition, the lt gene is the most prevalent enterotoxin gene accompanied by the ETEC strains, either alone or in combination with sta and/or f41 genes. The majority of pathogenic E. coli incriminated in calf diarrhea possesses the aadB resistance gene, followed by the sul1 gene. Enrofloxacin, florfenicol, amoxicillin-clavulanic acid, and ampicillin-sulbactam, are the most effective antimicrobial agents against the isolated STEC and ETEC strains. Full article
(This article belongs to the Special Issue Factors Governing the Persistence, Infection, Virulence and Treatment of Shiga Toxin-Encoding E. coli (STEC))
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