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Matsumoto Y, Lee K, Akasaka R, Honjo H, Koizumi M, Sato T, Kubomura A, Ishijima N, Akeda Y, Ohnishi M, Iyoda S. Increased resistance against tellurite is conferred by a mutation in the promoter region of uncommon tellurite resistance gene tehB in the ter-negative Shiga toxin-producing Escherichia coli O157:H7. Appl Environ Microbiol 2024; 90:e0228323. [PMID: 38757978 PMCID: PMC11218618 DOI: 10.1128/aem.02283-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Accepted: 04/18/2024] [Indexed: 05/18/2024] Open
Abstract
Resistance to potassium tellurite (PT) is an important indicator in isolating Shiga toxin-producing Escherichia coli (STEC) O157:H7 and other major STEC serogroups. Common resistance determinant genes are encoded in the ter gene cluster. We found an O157:H7 isolate that does not harbor ter but is resistant to PT. One nonsynonymous mutation was found in another PT resistance gene, tehA, through whole-genome sequence analyses. To elucidate the contribution of this mutation to PT resistance, complementation of tehA and the related gene tehB in isogenic strains and quantitative RT‒PCR were performed. The results indicated that the point mutation not only changed an amino acid of tehA, but also was positioned on a putative internal promoter of tehB and increased PT resistance by elevating tehB mRNA expression. Meanwhile, the amino acid change in tehA had negligible impact on the PT resistance. Comprehensive screening revealed that 2.3% of O157:H7 isolates in Japan did not harbor the ter gene cluster, but the same mutation in tehA was not found. These results suggested that PT resistance in E. coli can be enhanced through one mutational event even in ter-negative strains. IMPORTANCE Selective agents are important for isolating Shiga toxin-producing Escherichia coli (STEC) because the undesirable growth of microflora should be inhibited. Potassium tellurite (PT) is a common selective agent for major STEC serotypes. In this study, we found a novel variant of PT resistance genes, tehAB, in STEC O157:H7. Molecular experiments clearly showed that one point mutation in a predicted internal promoter region of tehB upregulated the expression of the gene and consequently led to increased resistance to PT. Because tehAB genes are ubiquitous across E. coli, these results provide universal insight into PT resistance in this species.
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Affiliation(s)
| | - Kenichi Lee
- Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan
| | - Ryuya Akasaka
- Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan
- Tokyo College of Biotechnology, Tokyo, Japan
| | - Hayato Honjo
- Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan
- Tokyo College of Biotechnology, Tokyo, Japan
| | | | - Toshio Sato
- Japan Microbiological Laboratory Co. Ltd., Miyagi, Japan
| | - Akiko Kubomura
- Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan
| | - Nozomi Ishijima
- Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan
| | - Yukihiro Akeda
- Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan
| | - Makoto Ohnishi
- Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan
| | - Sunao Iyoda
- Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan
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Kalalah AA, Koenig SSK, Feng P, Bosilevac JM, Bono JL, Eppinger M. Pathogenomes of Shiga Toxin Positive and Negative Escherichia coli O157:H7 Strains TT12A and TT12B: Comprehensive Phylogenomic Analysis Using Closed Genomes. Microorganisms 2024; 12:699. [PMID: 38674643 PMCID: PMC11052207 DOI: 10.3390/microorganisms12040699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2024] [Revised: 03/18/2024] [Accepted: 03/26/2024] [Indexed: 04/28/2024] Open
Abstract
Shiga toxin-producing Escherichia coli are zoonotic pathogens that cause food-borne human disease. Among these, the O157:H7 serotype has evolved from an enteropathogenic O55:H7 ancestor through the displacement of the somatic gene cluster and recurrent toxigenic conversion by Shiga toxin-converting bacteriophages. However, atypical strains that lack the Shiga toxin, the characteristic virulence hallmark, are circulating in this lineage. For this study, we analyzed the pathogenome and virulence inventories of the stx+ strain, TT12A, isolated from a patient with hemorrhagic colitis, and its respective co-isolated stx- strain, TT12B. Sequencing the genomes to closure proved critical to the cataloguing of subtle strain differentiating sequence and structural polymorphisms at a high-level of phylogenetic accuracy and resolution. Phylogenomic profiling revealed SNP and MLST profiles similar to the near clonal outbreak isolates. Their prophage inventories, however, were notably different. The attenuated atypical non-shigatoxigenic status of TT12B is explained by the absence of both the ΦStx1a- and ΦStx2a-prophages carried by TT12A, and we also recorded further alterations in the non-Stx prophage complement. Phenotypic characterization indicated that culture growth was directly impacted by the strains' distinct lytic phage complement. Altogether, our phylogenomic and phenotypic analyses show that these intimately related isogenic strains are on divergent Stx(+/stx-) evolutionary paths.
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Affiliation(s)
- Anwar A. Kalalah
- Department of Molecular Microbiology and Immunology, University of Texas at San Antonio, San Antonio, TX 78249, USA
- South Texas Center for Emerging Infectious Diseases (STCEID), San Antonio, TX 78249, USA
| | - Sara S. K. Koenig
- Department of Molecular Microbiology and Immunology, University of Texas at San Antonio, San Antonio, TX 78249, USA
- South Texas Center for Emerging Infectious Diseases (STCEID), San Antonio, TX 78249, USA
| | - Peter Feng
- U.S. Food and Drug Administration (FDA), College Park, MD 20740, USA
| | - Joseph M. Bosilevac
- U.S. Department of Agriculture (USDA), Agricultural Research Service (ARS), U.S. Meat Animal Research Center, Clay Center, NE 68933, USA
| | - James L. Bono
- U.S. Department of Agriculture (USDA), Agricultural Research Service (ARS), U.S. Meat Animal Research Center, Clay Center, NE 68933, USA
| | - Mark Eppinger
- Department of Molecular Microbiology and Immunology, University of Texas at San Antonio, San Antonio, TX 78249, USA
- South Texas Center for Emerging Infectious Diseases (STCEID), San Antonio, TX 78249, USA
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Zheng T, Li X, Xie YN, Yang B, Wu P. Dual-Gene Isothermal Amplification Coupled with Lateral Flow Strip for On-Site Accurate Detection of E. coli O157:H7 in Food Samples. Anal Chem 2023; 95:6053-6060. [PMID: 36977355 DOI: 10.1021/acs.analchem.3c00141] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/30/2023]
Abstract
On-site field detection of E. coli O157:H7 in food samples is of utmost importance, since it causes a series of foodborne diseases due to infections-associated ready-to-eat foods. Due to the instrument-free nature, recombinase polymerase amplification (RPA) coupled with lateral flow assay (LFA) is well-suited for such goal. However, the high genomic similarity of different E. coli serotypes adds difficulty to accurate differentiation of E. coli O157:H7 from others. Dual-gene analysis could significantly improve the serotype selectivity, but will further aggravate the RPA artifacts. To address such issue, here we proposed a protocol of dual-gene RPA-LFA, in which the target amplicons were selectively recognized by peptide nucleic acid (PNA) and T7 exonuclease (TeaPNA), thus eliminating false-positives in LFA readout. Adapting rfbEO157 and fliCH7 genes as the targets, dual-gene RPA-TeaPNA-LFA was demonstrated to be selective for E. coli O157:H7 over other E. coli serotypes and common foodborne bacteria. The minimum detection concentration was 10 copies/μL for the genomic DNA (∼300 cfu/mL E. coli O157:H7), and 0.24 cfu/mL E. coli O157:H7 in food samples after 5 h bacterial preculture. For lettuce samples contaminated with E. coli O157:H7 (single-blind), the sensitivity and specificity of the proposed method were 85% and 100%, respectively. Using DNA releaser for fast genomic DNA extraction, the assay time could be reduced to ∼1 h, which is appealing for on-site food monitoring.
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Affiliation(s)
- Ting Zheng
- Analytical & Testing Centre, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu 610064, China
| | - Xianming Li
- Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Ya-Ni Xie
- Analytical & Testing Centre, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu 610064, China
| | - Bin Yang
- Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Peng Wu
- Analytical & Testing Centre, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu 610064, China
- School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang 453007, China
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The Prophage and Us-Shiga Toxin Phages Revisited. Pathogens 2023; 12:pathogens12020232. [PMID: 36839504 PMCID: PMC9960153 DOI: 10.3390/pathogens12020232] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 01/31/2023] [Indexed: 02/05/2023] Open
Abstract
The authors first met in 1998 at the University of Würzburg, Germany, at the Institute of Hygiene and Microbiology, in Helge Karch's lab, where Herbert Schmidt worked as a PostDoc and Maite Muniesa visited the lab for a postdoctoral research stay to work on phages encoding Shiga toxin 2e (Stx2e) [...].
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Calvo PA, Mateo-Cáceres V, Díaz-Arco S, Redrejo-Rodríguez M, de Vega M. The enterohemorrhagic Escherichia coli insertion sequence-excision enhancer protein is a DNA polymerase with microhomology-mediated end-joining activity. Nucleic Acids Res 2023; 51:1189-1207. [PMID: 36715333 PMCID: PMC9943667 DOI: 10.1093/nar/gkad017] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 12/30/2022] [Accepted: 01/05/2023] [Indexed: 01/31/2023] Open
Abstract
Bacterial genomes contain an abundance of transposable insertion sequence (IS) elements that are essential for genome evolution and fitness. Among them, IS629 is present in most strains of enterohemorrhagic Escherichia coli O157 and accounts for many polymorphisms associated with gene inactivation and/or genomic deletions. The excision of IS629 from the genome is promoted by IS-excision enhancer (IEE) protein. Despite IEE has been identified in the most pathogenic serotypes of E. coli, its biochemical features that could explain its role in IS excision are not yet understood. We show that IEE is present in >30% of all available E. coli genome assemblies, and is highly conserved and very abundant within enterohemorrhagic, enteropathogenic and enterotoxigenic genomes. In vitro analysis of the recombinant protein from E. coli O157:H7 revealed the presence of a Mn2+-dependent error-prone DNA polymerase activity in its N-terminal archaeo-eukaryotic primase (AEP) domain able to promote dislocations of the primer and template strands. Importantly, IEE could efficiently perform in vitro an end-joining reaction of 3'-single-strand DNA overhangs with ≥4 bp of homology requiring both the N-terminal AEP and C-terminal helicase domains. The proposed role for IEE in the novel IS excision mechanism is discussed.
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Affiliation(s)
- Patricia A Calvo
- Centro de Biología Molecular Severo Ochoa (Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid), Nicolás Cabrera 1, Madrid 28049, Spain
| | - Víctor Mateo-Cáceres
- Department of Biochemistry, School of Medicine, Universidad Autónoma de Madrid and Instituto de Investigaciones Biomédicas Alberto Sols (Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas), Madrid, Spain
| | - Silvia Díaz-Arco
- Centro de Biología Molecular Severo Ochoa (Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid), Nicolás Cabrera 1, Madrid 28049, Spain
| | - Modesto Redrejo-Rodríguez
- Department of Biochemistry, School of Medicine, Universidad Autónoma de Madrid and Instituto de Investigaciones Biomédicas Alberto Sols (Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas), Madrid, Spain
| | - Miguel de Vega
- To whom correspondence should be addressed. Tel: +34 911964717; Fax: +34 911964420;
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Escherichia coli O157:H7 senses microbiota-produced riboflavin to increase its virulence in the gut. Proc Natl Acad Sci U S A 2022; 119:e2212436119. [PMID: 36409903 PMCID: PMC9860305 DOI: 10.1073/pnas.2212436119] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Riboflavin is produced by most commensal bacteria in the human colon, where enterohemorrhagic Escherichia coli (EHEC) colonizes and causes diseases. Sensing environmental signals to site-specifically express the type-III secretion system (T3SS), which injects effectors into host cells leading to intestinal colonization and disease, is key to the pathogenesis of EHEC. Here, we reveal that EHEC O157:H7, a dominant EHEC serotype frequently associated with severe diseases, acquired a previously uncharacterized two-component regulatory system rbfSR, which senses microbiota-produced riboflavin to directly activate the expression of LEE genes encoding the T3SS in the colon. rbfSR is present in O157:H7 and O145:H28 but absent from other EHEC serotypes. The binding site of RbfR through which it regulates LEE gene expression was identified and is conserved in all EHEC serotypes and Citrobacter rodentium, a surrogate for EHEC in mice. Introducing rbfSR into C. rodentium enabled bacteria to sense microbiota-produced riboflavin in the mouse colon to increase the expression of LEE genes, causing increased disease severity in mice. Phylogenic analysis showed that the O55:H7 ancestor of O157:H7 obtained rbfSR which has been kept in O157:H7 since then. Thus, acquiring rbfSR represents an essential step in the evolution of the highly pathogenic O157:H7. The expression of LEE genes and cell attachment ability of other EHEC serotypes in the presence of riboflavin significantly increased when rbfSR was introduced into them, indicating that those serotypes are ready to use RbfSR to increase their pathogenicity. This may present a potential public health issue as horizontal gene transfer is frequent in enteric bacteria.
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Insertion Sequence (IS)-Excision Enhancer (IEE)-Mediated IS Excision from the lacZ Gene Restores the Lactose Utilization Defect of Shiga Toxin-Producing Escherichia coli O121:H19 Strains and Is Responsible for Their Delayed Lactose Utilization Phenotype. Appl Environ Microbiol 2022; 88:e0076022. [PMID: 35913153 PMCID: PMC9397093 DOI: 10.1128/aem.00760-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Lactose utilization is one of the general biochemical characteristics of Escherichia coli, and the lac operon is responsible for this phenotype, which can be detected on lactose-containing media, such as MacConkey agar, after 24 h of incubation. However, some Shiga toxin-producing E. coli (STEC) O121:H19 strains exhibit an unusual phenotype called delayed lactose utilization (DLU), in which lactose utilization can be detected after 48 h of cultivation but not after only 24 h of cultivation. Insertion of an insertion sequence (IS), IS600, into the lacZ gene appears to be responsible for the DLU phenotype, and exposure to lactose has been reported to be necessary to observe this phenotype, but the mechanism underlying these phenomena remains to be elucidated. Here, we performed detailed analyses of the lactose utilization abilities of a set of O121:H19 strains and their mutants and found that IS-excision enhancer (IEE)-mediated excision of IS600 reactivates the lacZ gene and that the selective proliferation of IS-cured subclones in lactose-supplemented culture medium is responsible for the expression of the DLU phenotype. In addition, we analyzed the patterns of IS insertion into the lacZ and iee genes in the global O121:H19 population and revealed that while there are O121:H19 strains or lineage/sublineages that contain the IS insertion into iee or intact lacZ and thus do not show the DLU phenotype, most currently circulating O121:H19 strains contain IS600-inserted lacZ and intact iee and thus exhibit this phenotype. IMPORTANCE Insertion sequences (ISs) can modulate gene expression by gene inactivation or activation. While phenotypic changes due to IS insertion/transposition are frequently observed, gene reactivation by precise or simple IS excision rarely occurs. In this study, we show that IS600 is excised from the lacZ gene by IS-excision enhancer (IEE) during the cultivation of Shiga toxin-producing Escherichia coli (STEC) O121:H19 strains that show an unusual phenotype called delayed lactose utilization (DLU). This excision rescued their lactose utilization defect, and the subsequent selective proliferation of IS-cured subclones in lactose-containing medium resulted in the expression of the DLU phenotype. As we also show that most currently circulating O121:H19 strains exhibit this phenotype, this study not only provides information helpful for the isolation and identification of O121:H19 STEC but also offers novel insights into the roles of IS and IEE in the generation of phenotypic variation in bacterial populations.
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Comparative Genomics Applied to Systematically Assess Pathogenicity Potential in Shiga Toxin-Producing Escherichia coli O145:H28. Microorganisms 2022; 10:microorganisms10050866. [PMID: 35630311 PMCID: PMC9144400 DOI: 10.3390/microorganisms10050866] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 04/14/2022] [Accepted: 04/19/2022] [Indexed: 01/27/2023] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) O145:H28 can cause severe disease in humans and is a predominant serotype in STEC O145 environmental isolates. Here, comparative genomics was applied to a set of clinical and environmental strains to systematically evaluate the pathogenicity potential in environmental strains. While the core genes-based tree separated all O145:H28 strains from the non O145:H28 reference strains, it failed to segregate environmental strains from the clinical. In contrast, the accessory genes-based tree placed all clinical strains in the same clade regardless of their genotypes or serotypes, apart from the environmental strains. Loss-of-function mutations were common in the virulence genes examined, with a high frequency in genes related to adherence, autotransporters, and the type three secretion system. Distinct differences in pathogenicity islands LEE, OI-122, and OI-57, the acid fitness island, and the tellurite resistance island were detected between the O145:H28 and reference strains. A great amount of genetic variation was detected in O145:H28, which was mainly attributed to deletions, insertions, and gene acquisition at several chromosomal “hot spots”. Our study demonstrated a distinct virulence gene repertoire among the STEC O145:H28 strains originating from the same geographical region and revealed unforeseen contributions of loss-of-function mutations to virulence evolution and genetic diversification in STEC.
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Carbonari CC, Miliwebsky ES, Zolezzi G, Deza NL, Fittipaldi N, Manfredi E, Baschkier A, D’Astek BA, Melano RG, Schesi C, Rivas M, Chinen I. The Importance of Shiga Toxin-Producing Escherichia coli O145:NM[H28]/H28 Infections in Argentina, 1998–2020. Microorganisms 2022; 10:microorganisms10030582. [PMID: 35336157 PMCID: PMC8950694 DOI: 10.3390/microorganisms10030582] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2021] [Revised: 11/25/2021] [Accepted: 11/29/2021] [Indexed: 02/01/2023] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) is known as a pathogen associated with food-borne diseases. The STEC O145 serogroup has been related with acute watery diarrhea, bloody diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome (HUS). Argentina has the highest rate of HUS worldwide with 70% of the cases associated with STEC infections. We aimed to describe the epidemiology and genetic diversity of STEC O145 strains isolated across Argentina between 1998–2020. The strains isolated from 543 cases of human disease and four cattle, were pheno-genotipically characterized. Sequencing of five strains was performed. The strains were serotyped as O145:NM[H28]/H28, O145:H25, and O145:HNT, and mainly characterized as O145:NM[H28]/stx2a/eae/ehxA (98.1%). The results obtained by sequencing were consistent with those obtained by traditional methods and additional genes involved in different mechanisms of the pathogen were observed. In this study, we confirmed that STEC O145 strains are the second serogroup after O157 and represent 20.3% of HUS cases in Argentina. The frequency of STEC O145 and other significant serogroups is of utmost importance for public health in the country. This study encourages the improvement of the surveillance system to prevent severe cases of human disease.
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Affiliation(s)
- Claudia Carolina Carbonari
- Servicio Fisiopatogenia, Departamento Bacteriología, Instituto Nacional de Enfermedades Infecciosas-ANLIS “Dr. Carlos G. Malbrán”, Buenos Aires 1282, Argentina; (E.S.M.); (G.Z.); (N.L.D.); (E.M.); (A.B.); (B.A.D.); (C.S.); (M.R.); (I.C.)
- Correspondence:
| | - Elizabeth Sandra Miliwebsky
- Servicio Fisiopatogenia, Departamento Bacteriología, Instituto Nacional de Enfermedades Infecciosas-ANLIS “Dr. Carlos G. Malbrán”, Buenos Aires 1282, Argentina; (E.S.M.); (G.Z.); (N.L.D.); (E.M.); (A.B.); (B.A.D.); (C.S.); (M.R.); (I.C.)
| | - Gisela Zolezzi
- Servicio Fisiopatogenia, Departamento Bacteriología, Instituto Nacional de Enfermedades Infecciosas-ANLIS “Dr. Carlos G. Malbrán”, Buenos Aires 1282, Argentina; (E.S.M.); (G.Z.); (N.L.D.); (E.M.); (A.B.); (B.A.D.); (C.S.); (M.R.); (I.C.)
| | - Natalia Lorena Deza
- Servicio Fisiopatogenia, Departamento Bacteriología, Instituto Nacional de Enfermedades Infecciosas-ANLIS “Dr. Carlos G. Malbrán”, Buenos Aires 1282, Argentina; (E.S.M.); (G.Z.); (N.L.D.); (E.M.); (A.B.); (B.A.D.); (C.S.); (M.R.); (I.C.)
| | - Nahuel Fittipaldi
- Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, QC J2S 2M2, Canada;
| | - Eduardo Manfredi
- Servicio Fisiopatogenia, Departamento Bacteriología, Instituto Nacional de Enfermedades Infecciosas-ANLIS “Dr. Carlos G. Malbrán”, Buenos Aires 1282, Argentina; (E.S.M.); (G.Z.); (N.L.D.); (E.M.); (A.B.); (B.A.D.); (C.S.); (M.R.); (I.C.)
| | - Ariela Baschkier
- Servicio Fisiopatogenia, Departamento Bacteriología, Instituto Nacional de Enfermedades Infecciosas-ANLIS “Dr. Carlos G. Malbrán”, Buenos Aires 1282, Argentina; (E.S.M.); (G.Z.); (N.L.D.); (E.M.); (A.B.); (B.A.D.); (C.S.); (M.R.); (I.C.)
| | - Beatriz Alejandra D’Astek
- Servicio Fisiopatogenia, Departamento Bacteriología, Instituto Nacional de Enfermedades Infecciosas-ANLIS “Dr. Carlos G. Malbrán”, Buenos Aires 1282, Argentina; (E.S.M.); (G.Z.); (N.L.D.); (E.M.); (A.B.); (B.A.D.); (C.S.); (M.R.); (I.C.)
| | - Roberto Gustavo Melano
- Public Health Ontario, Toronto Laboratories, Toronto, ON M5G 1M1, Canada;
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON M5G 1M1, Canada
| | - Carla Schesi
- Servicio Fisiopatogenia, Departamento Bacteriología, Instituto Nacional de Enfermedades Infecciosas-ANLIS “Dr. Carlos G. Malbrán”, Buenos Aires 1282, Argentina; (E.S.M.); (G.Z.); (N.L.D.); (E.M.); (A.B.); (B.A.D.); (C.S.); (M.R.); (I.C.)
| | - Marta Rivas
- Servicio Fisiopatogenia, Departamento Bacteriología, Instituto Nacional de Enfermedades Infecciosas-ANLIS “Dr. Carlos G. Malbrán”, Buenos Aires 1282, Argentina; (E.S.M.); (G.Z.); (N.L.D.); (E.M.); (A.B.); (B.A.D.); (C.S.); (M.R.); (I.C.)
| | - Isabel Chinen
- Servicio Fisiopatogenia, Departamento Bacteriología, Instituto Nacional de Enfermedades Infecciosas-ANLIS “Dr. Carlos G. Malbrán”, Buenos Aires 1282, Argentina; (E.S.M.); (G.Z.); (N.L.D.); (E.M.); (A.B.); (B.A.D.); (C.S.); (M.R.); (I.C.)
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Ramstad SN, Wasteson Y, Lindstedt BA, Taxt AM, Bjørnholt JV, Brandal LT, Bohlin J. Characterization of Shiga Toxin 2a Encoding Bacteriophages Isolated From High-Virulent O145:H25 Shiga Toxin-Producing Escherichia coli. Front Microbiol 2021; 12:728116. [PMID: 34566932 PMCID: PMC8456039 DOI: 10.3389/fmicb.2021.728116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2021] [Accepted: 07/19/2021] [Indexed: 11/20/2022] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) may cause severe disease mainly due to the ability to produce Shiga toxins (Stx) encoded on bacteriophages. In Norway, more than 30% of the reported cases with STEC O145:H25 develop hemolytic uremic syndrome (HUS), and most cases, with known travel history, acquired the infection domestically. To describe phage characteristics associated with high virulence, we extracted the Stx2a phage sequences from eight clinical Norwegian O145:H25 STEC to conduct in-depth molecular characterization using long and short read sequencing. The Stx2a phages were annotated, characterized, and compared with previously published Stx2a phages isolated from STEC of different serotypes. The Norwegian O145:H25 Stx2a phages showed high sequence identity (>99%) with 100% coverage. The Stx2a phages were located at the integration site yciD, were approximately 45 kbp long, and harbored several virulence-associated genes, in addition to stx2a, such as nanS and nleC. We observed high sequence identity (>98%) and coverage (≥94%) between Norwegian O145:H25 Stx2a phages and publicly available Stx2a phages from O145:H25 and O145:H28 STEC, isolated from HUS cases in the USA and a hemorrhagic diarrhea case from Japan, respectively. However, low similarity was seen when comparing the Norwegian O145:H25 Stx2a phage to Stx2a phages from STEC of other serotypes. In all the Norwegian O145:H25 STEC, we identified a second phage or remnants of a phage (a shadow phage, 61 kbp) inserted at the same integration site as the Stx2a phage. The shadow phage shared similarity with the Stx2a phage, but lacked stx2a and harbored effector genes not present in the Stx2a phage. We identified a conserved Stx2a phage among the Norwegian O145:H25 STEC that shared integration site with a shadow phage in all isolates. Both phage and shadow phage harbored several virulence-associated genes that may contribute to the increased pathogenicity of O145:H25 STEC.
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Affiliation(s)
- Silje N Ramstad
- Department of Microbiology, Division of Laboratory Medicine, Oslo University Hospital, Oslo, Norway.,Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Yngvild Wasteson
- Department of Paraclinical Sciences, Norwegian University of Life Sciences, Oslo, Norway
| | - Bjørn-Arne Lindstedt
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Arne M Taxt
- Department of Microbiology, Division of Laboratory Medicine, Oslo University Hospital, Oslo, Norway.,Department of Infectious Diseases and Prevention, Norwegian Institute of Public Health, Oslo, Norway
| | - Jørgen V Bjørnholt
- Department of Microbiology, Division of Laboratory Medicine, Oslo University Hospital, Oslo, Norway.,Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Lin T Brandal
- Division of Infection Control and Environmental Health, Norwegian Institute of Public Health, Oslo, Norway.,ECDC Fellowship Programme, Public Health Microbiology Path (EUPHEM), European Centre for Disease Prevention and Control (ECDC), Solna, Sweden
| | - Jon Bohlin
- Division of Infection Control and Environmental Health, Norwegian Institute of Public Health, Oslo, Norway
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11
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Nguyen TTH, Kikuchi T, Tokunaga T, Iyoda S, Iguchi A. Diversity of the Tellurite Resistance Gene Operon in Escherichia coli. Front Microbiol 2021; 12:681175. [PMID: 34122392 PMCID: PMC8193136 DOI: 10.3389/fmicb.2021.681175] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 04/30/2021] [Indexed: 11/15/2022] Open
Abstract
Tellurite is highly toxic to most bacteria owing to its strong oxidative ability. However, some bacteria demonstrate tellurite resistance. In particular, some Escherichia coli strains, including Shiga toxin-producing E. coli O157:H7, are known to be resistant to tellurite. This resistance is involved in ter operon, which is usually located on a prophage-like element of the chromosome. The characteristics of the ter operon have been investigated mainly by genome analysis of pathogenic E. coli; however, the distribution and structural characteristics of the ter operon in other E. coli are almost unknown. To clarify these points, we examined 106 E. coli strains carrying the ter operon from various animals. The draft genomes of 34 representative strains revealed that ter operons were clearly classified into four subtypes, ter-type 1–4, at the nucleotide sequence level. Complete genomic sequences revealed that operons belonging to three ter-types (1, 3, and 4) were located on the prophage-like elements on the chromosome, whereas the ter-type 2 operon was located on the IncHI2 plasmid. The positions of the tRNASer, tRNAMet, and tRNAPhe indicated the insertion sites of elements carrying the ter operons. Using the PCR method developed in this study, 106 strains were classified as type 1 (n = 66), 2 (n = 13), 3 (n = 8), and 4 (n = 17), and two strains carried both types 1 and 2. Furthermore, significant differences in the minimum inhibitory concentration (MIC) of tellurite were observed between strains carrying ter-type 4 and the others (p < 0.05). The ter-type was also closely related to the isolation source, with types 2 and 4 associated with chickens and deer, respectively. This study provided new insights related not only to genetic characteristics of the ter operons, but also to phenotypic and ecological characteristics that may be related to the diversity of the operon.
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Affiliation(s)
- Thi Thu Huong Nguyen
- Department of Environment and Resource Sciences, University of Miyazaki, Miyazaki, Japan.,Thai Nguyen University of Agriculture and Forestry, Thai Nguyen, Vietnam
| | - Taisei Kikuchi
- Department of Infectious Disease, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan
| | - Tadaaki Tokunaga
- Department of Environment and Resource Sciences, University of Miyazaki, Miyazaki, Japan
| | - Sunao Iyoda
- Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan
| | - Atsushi Iguchi
- Department of Environment and Resource Sciences, University of Miyazaki, Miyazaki, Japan
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12
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Nakamura K, Ogura Y, Gotoh Y, Hayashi T. Prophages integrating into prophages: A mechanism to accumulate type III secretion effector genes and duplicate Shiga toxin-encoding prophages in Escherichia coli. PLoS Pathog 2021; 17:e1009073. [PMID: 33914852 PMCID: PMC8112680 DOI: 10.1371/journal.ppat.1009073] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 05/11/2021] [Accepted: 04/14/2021] [Indexed: 11/20/2022] Open
Abstract
Bacteriophages (or phages) play major roles in the evolution of bacterial pathogens via horizontal gene transfer. Multiple phages are often integrated in a host chromosome as prophages, not only carrying various novel virulence-related genetic determinants into host bacteria but also providing various possibilities for prophage-prophage interactions in bacterial cells. In particular, Escherichia coli strains such as Shiga toxin (Stx)-producing E. coli (STEC) and enteropathogenic E. coli (EPEC) strains have acquired more than 10 prophages (up to 21 prophages), many of which encode type III secretion system (T3SS) effector gene clusters. In these strains, some prophages are present at a single locus in tandem, which is usually interpreted as the integration of phages that use the same attachment (att) sequence. Here, we present phages integrating into T3SS effector gene cluster-associated loci in prophages, which are widely distributed in STEC and EPEC. Some of the phages integrated into prophages are Stx-encoding phages (Stx phages) and have induced the duplication of Stx phages in a single cell. The identified attB sequences in prophage genomes are apparently derived from host chromosomes. In addition, two or three different attB sequences are present in some prophages, which results in the generation of prophage clusters in various complex configurations. These phages integrating into prophages represent a medically and biologically important type of inter-phage interaction that promotes the accumulation of T3SS effector genes in STEC and EPEC, the duplication of Stx phages in STEC, and the conversion of EPEC to STEC and that may be distributed in other types of E. coli strains as well as other prophage-rich bacterial species. Multiple prophages are often integrated in a bacterial host chromosome and some are present at a single locus in tandem. The most striking examples are Shiga toxin (Stx)-producing and enteropathogenic Escherichia coli (STEC and EPEC) strains, which usually contain more than 10 prophages (up to 21). Many of them encode a cluster of type III secretion system (T3SS) effector genes, contributing the acquisition of a large number of effectors (>30) by STEC and EPEC. Here, we describe prophages integrating into T3SS effector gene cluster-associated loci in prophages, which are widely distributed in STEC and EPEC. Two or three different attachment sequences derived from host chromosomes are present in some prophages, generating prophage clusters in various complex configurations. Of note, some of such phages integrating into prophages are Stx-encoding phages (Stx phages) and have induced the duplication of Stx phages. Thus, “prophage-in-prophage” represents an important inter-phage interaction as they can promote not only the accumulation of T3SS effectors in STEC and EPEC but also the duplication of Stx phages and the conversion of EPEC to STEC.
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Affiliation(s)
- Keiji Nakamura
- Department of Bacteriology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Yoshitoshi Ogura
- Division of Microbiology, Department of Infectious Medicine, Kurume University School of Medicine, Kurume, Japan
| | - Yasuhiro Gotoh
- Department of Bacteriology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Tetsuya Hayashi
- Department of Bacteriology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
- * E-mail:
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13
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Guerra JA, Zhang C, Bard JE, Yergeau D, Halasa N, Gómez-Duarte OG. Comparative genomic analysis of a Shiga toxin-producing Escherichia coli (STEC) O145:H25 associated with a severe pediatric case of hemolytic uremic syndrome in Davidson County, Tennessee, US. BMC Genomics 2020; 21:564. [PMID: 32807093 PMCID: PMC7437938 DOI: 10.1186/s12864-020-06967-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 08/03/2020] [Indexed: 12/02/2022] Open
Abstract
Background Shiga toxin-producing E. coli (STECs) are foodborne pathogens associated with bloody diarrhea and hemolytic uremic syndrome (HUS). Although the STEC O157 serogroup accounts for the highest number of infections, HUS-related complications and deaths, the STEC non-O157, as a group, accounts for a larger proportion of STEC infections and lower HUS cases. There is limited information available on how to recognize non-O157 serotypes associated with severe disease. The objectives of this study were to describe a patient with STEC non-O157 infection complicated with HUS and to conduct a comparative whole genome sequence (WGS) analysis among the patient’s STEC clinical isolate and STEC O157 and non-O157 strains. Results The STEC O145:H25 strain EN1I-0044-2 was isolated from a pediatric patient with diarrhea, HUS and severe neurologic and cardiorespiratory complications, who was enrolled in a previously reported case-control study of acute gastroenteritis conducted in Davidson County, Tennessee in 2013. The strain EN1I-0044-2 genome sequence contained a chromosome and three plasmids. Two of the plasmids were similar to those present in O145:H25 strains whereas the third unique plasmid EN1I-0044-2_03 shared no similarity with other STEC plasmids, and it carried 23 genes of unknown function. Strain EN1I-0044-2, compared with O145:H25 and O157 serogroup strains shared chromosome- and plasmid-encoded virulence factors, including Shiga toxin, LEE type III secretion system, LEE effectors, SFP fimbriae, and additional toxins and colonization factors. Conclusions A STEC O145:H25 strain EN1I-0044-2 was isolated from a pediatric patient with severe disease, including HUS, in Davidson County, TN. Phylogenetic and comparison WGS analysis provided evidence that strain EN1I-0044-2 closely resembles O145:H25, and confirmed an independent evolutionary path of STEC O145:H25 and O145:H28 serotypes. The strain EN1I-0044-2 virulence make up was similar to other O145:H25 and O157 serogroups. It carried stx2 and the LEE pathogenicity island, and additional colonization factors and enterotoxin genes. A unique feature of strain EN1I-0044-2 was the presence of plasmid pEN1I-0044-2_03 carrying genes with functions to be determined. Further studies will be necessary to elucidate the role that newly acquired genes by O145:H25 strains play in pathogenesis, and to determine if they may serve as genetic markers of severe disease.
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Affiliation(s)
- Julio A Guerra
- International Enteric Vaccine Research Program, Division of Infectious Diseases, Department of Pediatrics, University at Buffalo, The State University of New York (SUNY), Jacobs School of Medicine and Biomedical Sciences, 875 Ellicott St. Office 6090, Buffalo, NY, 14203, USA
| | - Chengxian Zhang
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Jonathan E Bard
- UB Genomics and Bioinformatics Core, Center of Excellence in Bioinformatics, University at Buffalo, The State University of New York, Buffalo, NY, USA
| | - Donald Yergeau
- UB Genomics and Bioinformatics Core, Center of Excellence in Bioinformatics, University at Buffalo, The State University of New York, Buffalo, NY, USA
| | - Natasha Halasa
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Oscar G Gómez-Duarte
- International Enteric Vaccine Research Program, Division of Infectious Diseases, Department of Pediatrics, University at Buffalo, The State University of New York (SUNY), Jacobs School of Medicine and Biomedical Sciences, 875 Ellicott St. Office 6090, Buffalo, NY, 14203, USA. .,Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, TN, USA.
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14
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Collis RM, Biggs PJ, Midwinter AC, Browne AS, Wilkinson DA, Irshad H, French NP, Brightwell G, Cookson AL. Genomic epidemiology and carbon metabolism of Escherichia coli serogroup O145 reflect contrasting phylogenies. PLoS One 2020; 15:e0235066. [PMID: 32584859 PMCID: PMC7316241 DOI: 10.1371/journal.pone.0235066] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 06/08/2020] [Indexed: 11/18/2022] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) are a leading cause of foodborne outbreaks of human disease, but they reside harmlessly as an asymptomatic commensal in the ruminant gut. STEC serogroup O145 are difficult to isolate as routine diagnostic methods are unable to distinguish non-O157 serogroups due to their heterogeneous metabolic characteristics, resulting in under-reporting which is likely to conceal their true prevalence. In light of these deficiencies, the purpose of this study was a twofold approach to investigate enhanced STEC O145 diagnostic culture-based methods: firstly, to use a genomic epidemiology approach to understand the genetic diversity and population structure of serogroup O145 at both a local (New Zealand) (n = 47) and global scale (n = 75) and, secondly, to identify metabolic characteristics that will help the development of a differential media for this serogroup. Analysis of a subset of E. coli serogroup O145 strains demonstrated considerable diversity in carbon utilisation, which varied in association with eae subtype and sequence type. Several carbon substrates, such as D-serine and D-malic acid, were utilised by the majority of serogroup O145 strains, which, when coupled with current molecular and culture-based methods, could aid in the identification of presumptive E. coli serogroup O145 isolates. These carbon substrates warrant subsequent testing with additional serogroup O145 strains and non-O145 strains. Serogroup O145 strains displayed extensive genetic heterogeneity that was correlated with sequence type and eae subtype, suggesting these genetic markers are good indicators for distinct E. coli phylogenetic lineages. Pangenome analysis identified a core of 3,036 genes and an open pangenome of >14,000 genes, which is consistent with the identification of distinct phylogenetic lineages. Overall, this study highlighted the phenotypic and genotypic heterogeneity within E. coli serogroup O145, suggesting that the development of a differential media targeting this serogroup will be challenging.
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Affiliation(s)
- Rose M. Collis
- AgResearch Ltd, Hopkirk Research Institute, Massey University, Palmerston North, New Zealand
- Molecular Epidemiology and Veterinary Public Health Laboratory (EpiLab), Infectious Disease Research Centre, School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - Patrick J. Biggs
- Molecular Epidemiology and Veterinary Public Health Laboratory (EpiLab), Infectious Disease Research Centre, School of Veterinary Science, Massey University, Palmerston North, New Zealand
- School of Fundamental Sciences, Massey University, Palmerston North, New Zealand
- New Zealand Food Safety Science and Research Centre, Massey University, Palmerston North, New Zealand
| | - Anne C. Midwinter
- Molecular Epidemiology and Veterinary Public Health Laboratory (EpiLab), Infectious Disease Research Centre, School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - A. Springer Browne
- Molecular Epidemiology and Veterinary Public Health Laboratory (EpiLab), Infectious Disease Research Centre, School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - David A. Wilkinson
- Molecular Epidemiology and Veterinary Public Health Laboratory (EpiLab), Infectious Disease Research Centre, School of Veterinary Science, Massey University, Palmerston North, New Zealand
- New Zealand Food Safety Science and Research Centre, Massey University, Palmerston North, New Zealand
| | - Hamid Irshad
- Animal Health Programme, National Agricultural Research Centre, Islamabad, Pakistan
| | - Nigel P. French
- Molecular Epidemiology and Veterinary Public Health Laboratory (EpiLab), Infectious Disease Research Centre, School of Veterinary Science, Massey University, Palmerston North, New Zealand
- New Zealand Food Safety Science and Research Centre, Massey University, Palmerston North, New Zealand
| | - Gale Brightwell
- AgResearch Ltd, Hopkirk Research Institute, Massey University, Palmerston North, New Zealand
- New Zealand Food Safety Science and Research Centre, Massey University, Palmerston North, New Zealand
| | - Adrian L. Cookson
- AgResearch Ltd, Hopkirk Research Institute, Massey University, Palmerston North, New Zealand
- Molecular Epidemiology and Veterinary Public Health Laboratory (EpiLab), Infectious Disease Research Centre, School of Veterinary Science, Massey University, Palmerston North, New Zealand
- * E-mail:
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15
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Is Shiga Toxin-Producing Escherichia coli O45 No Longer a Food Safety Threat? The Danger is Still Out There. Microorganisms 2020; 8:microorganisms8050782. [PMID: 32455956 PMCID: PMC7285328 DOI: 10.3390/microorganisms8050782] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 05/16/2020] [Accepted: 05/18/2020] [Indexed: 01/03/2023] Open
Abstract
Many Shiga toxin-producing Escherichia coli (STEC) strains, including the serogroups of O157 and most of the top six non-O157 serotypes, are frequently associated with foodborne outbreaks. Therefore, they have been extensively studied using next-generation sequencing technology. However, related information regarding STEC O45 strains is scarce. In this study, three environmental E. coli O45:H16 strains (RM11911, RM13745, and RM13752) and one clinical E. coli O45:H2 strain (SJ7) were sequenced and used to characterize virulence factors using two reference E. coli O45:H2 strains of clinical origin. Subsequently, whole-genome-based phylogenetic analysis was conducted for the six STEC O45 strains and nine other reference STEC genomes, in order to evaluate their evolutionary relationship. The results show that one locus of enterocyte effacement pathogenicity island was found in all three STEC O45:H2 strains, but not in the STEC O45:H16 strains. Additionally, E. coli O45:H2 strains were evolutionarily close to E. coli O103:H2 strains, sharing high homology in terms of virulence factors, such as Stx prophages, but were distinct from E. coli O45:H16 strains. The findings show that E. coli O45:H2 may be as virulent as E. coli O103:H2, which is frequently associated with severe illness and can provide genomic evidence to facilitate STEC surveillance.
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16
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Nyong EC, Zaia SR, Allué-Guardia A, Rodriguez AL, Irion-Byrd Z, Koenig SSK, Feng P, Bono JL, Eppinger M. Pathogenomes of Atypical Non-shigatoxigenic Escherichia coli NSF/SF O157:H7/NM: Comprehensive Phylogenomic Analysis Using Closed Genomes. Front Microbiol 2020; 11:619. [PMID: 32351476 PMCID: PMC7175801 DOI: 10.3389/fmicb.2020.00619] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 03/19/2020] [Indexed: 12/19/2022] Open
Abstract
The toxigenic conversion of Escherichia coli strains by Shiga toxin-converting (Stx) bacteriophages were prominent and recurring events in the stepwise evolution of enterohemorrhagic E. coli (EHEC) O157:H7 from an enteropathogenic (EPEC) O55:H7 ancestor. Atypical, attenuated isolates have been described for both non-sorbitol fermenting (NSF) O157:H7 and SF O157:NM serotypes, which are distinguished by the absence of Stx, the characteristic virulence hallmark of Stx-producing E. coli (STEC). Such atypical isolates either never acquired Stx-phages or may have secondarily lost stx during the course of infection, isolation, or routine subculture; the latter are commonly referred to as LST (Lost Shiga Toxin)-isolates. In this study we analyzed the genomes of 15 NSF O157:H7 and SF O157:NM strains from North America, Europe, and Asia that are characterized by the absence of stx, the virulence hallmark of STEC. The individual genomic basis of the Stx (-) phenotype has remained largely undetermined as the majority of STEC genomes in public genome repositories were generated using short read technology and are in draft stage, posing a major obstacle for the high-resolution whole genome sequence typing (WGST). The application of LRT (long-read technology) sequencing provided us with closed genomes, which proved critical to put the atypical non-shigatoxigenic NSF O157:H7 and SF O157:NM strains into the phylogenomic context of the stepwise evolutionary model. Availability of closed chromosomes for representative Stx (-) NSF O157:H7 and SF O157:NM strains allowed to describe the genomic basis and individual evolutionary trajectories underlying the absence of Stx at high accuracy and resolution. The ability of LRT to recover and accurately assemble plasmids revealed a strong correlation between the strains' featured plasmid genotype and chromosomally inferred clade, which suggests the coevolution of the chromosome and accessory plasmids. The identified ancestral traits in the pSFO157 plasmid of NSF O157:H7 strain LSU-61 provided additional evidence for its intermediate status. Taken together, these observations highlight the utility of LRTs for advancing our understanding of EHEC O157:H7/NM pathogenome evolution. Insights into the genomic and phenotypic plasticity of STEC on a lineage- and genome-wide scale are foundational to improve and inform risk assessment, biosurveillance, and prevention strategies.
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Affiliation(s)
- Emmanuel C. Nyong
- Department of Biology, The University of Texas at San Antonio, San Antonio, TX, United States
- South Texas Center for Emerging Infectious Diseases, San Antonio, TX, United States
| | - Sam R. Zaia
- Department of Biology, The University of Texas at San Antonio, San Antonio, TX, United States
- South Texas Center for Emerging Infectious Diseases, San Antonio, TX, United States
| | - Anna Allué-Guardia
- Department of Biology, The University of Texas at San Antonio, San Antonio, TX, United States
- South Texas Center for Emerging Infectious Diseases, San Antonio, TX, United States
| | - Armando L. Rodriguez
- Research Computing Support Group, The University of Texas at San Antonio, San Antonio, TX, United States
| | - Zaina Irion-Byrd
- Department of Biology, The University of Texas at San Antonio, San Antonio, TX, United States
- South Texas Center for Emerging Infectious Diseases, San Antonio, TX, United States
| | - Sara S. K. Koenig
- Department of Biology, The University of Texas at San Antonio, San Antonio, TX, United States
- South Texas Center for Emerging Infectious Diseases, San Antonio, TX, United States
| | | | - James L. Bono
- United States Meat Animal Research Center, Agricultural Research Service, United States Department of Agriculture (ARS-USDA), Clay Center, NE, United States
| | - Mark Eppinger
- Department of Biology, The University of Texas at San Antonio, San Antonio, TX, United States
- South Texas Center for Emerging Infectious Diseases, San Antonio, TX, United States
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17
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Shakya M, Ahmed SA, Davenport KW, Flynn MC, Lo CC, Chain PSG. Standardized phylogenetic and molecular evolutionary analysis applied to species across the microbial tree of life. Sci Rep 2020; 10:1723. [PMID: 32015354 PMCID: PMC6997174 DOI: 10.1038/s41598-020-58356-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 01/06/2020] [Indexed: 12/02/2022] Open
Abstract
There is growing interest in reconstructing phylogenies from the copious amounts of genome sequencing projects that target related viral, bacterial or eukaryotic organisms. To facilitate the construction of standardized and robust phylogenies for disparate types of projects, we have developed a complete bioinformatic workflow, with a web-based component to perform phylogenetic and molecular evolutionary (PhaME) analysis from sequencing reads, draft assemblies or completed genomes of closely related organisms. Furthermore, the ability to incorporate raw data, including some metagenomic samples containing a target organism (e.g. from clinical samples with suspected infectious agents), shows promise for the rapid phylogenetic characterization of organisms within complex samples without the need for prior assembly.
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Affiliation(s)
- Migun Shakya
- Bioscience Division, Los Alamos National Laboratory, MS-M888, Los Alamos, NM, 87545, USA.
| | - Sanaa A Ahmed
- Bioscience Division, Los Alamos National Laboratory, MS-M888, Los Alamos, NM, 87545, USA
| | - Karen W Davenport
- Bioscience Division, Los Alamos National Laboratory, MS-M888, Los Alamos, NM, 87545, USA
| | - Mark C Flynn
- Bioscience Division, Los Alamos National Laboratory, MS-M888, Los Alamos, NM, 87545, USA
| | - Chien-Chi Lo
- Bioscience Division, Los Alamos National Laboratory, MS-M888, Los Alamos, NM, 87545, USA
| | - Patrick S G Chain
- Bioscience Division, Los Alamos National Laboratory, MS-M888, Los Alamos, NM, 87545, USA.
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18
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Migura-Garcia L, González-López JJ, Martinez-Urtaza J, Aguirre Sánchez JR, Moreno-Mingorance A, Perez de Rozas A, Höfle U, Ramiro Y, Gonzalez-Escalona N. mcr-Colistin Resistance Genes Mobilized by IncX4, IncHI2, and IncI2 Plasmids in Escherichia coli of Pigs and White Stork in Spain. Front Microbiol 2020; 10:3072. [PMID: 32010114 PMCID: PMC6978640 DOI: 10.3389/fmicb.2019.03072] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Accepted: 12/19/2019] [Indexed: 01/14/2023] Open
Abstract
Colistin has become the last-line antimicrobial for the treatment of multidrug resistant (MDR) Enterobacterales in human medicine. To date, several colistin resistance genes have been described. Of them mcr-1 is disseminated worldwide in Escherichia coli of human and animal origin. The aim of this study was to characterize mcr-mediated resistance plasmids from E. coli of animal origin in Spain. From our strain collection, 70 E. coli of pig origin collected between 2005 and 2014 (10 per year, except for years 2009–2010–2013) were randomly selected and screened for the presence of mcr-genes. Additionally, 20 E. coli isolated in 2011 from white storks (Ciconia ciconia) from the same urban household waste landfill associated colony were also included. Whole genome sequencing of mcr-positive isolates was carried out on a MiSeq (Illumina). Hybrid whole genome sequencing strategy combining nanopore and Illumina technologies were performed in a selection of isolates to close the genomes and plasmids and identify the presence of antimicrobial resistance genes. Minimum inhibitory concentration (MIC) was used to assess the susceptibility to colistin. Mating experiments were carried out to evaluate transferability of the mcr-genes. A total of 19 mcr-1 and one mcr-4 positive isolates were detected, 15 from pigs distributed during the study period, and five from storks collected in 2011. No other mcr-variants were found. The MICs for colistin ranged between 4 and >4 mg/L. High diversity of STs were detected among the mcr-1 positive E. coli isolates, with only ST-10 shared between pigs and white storks. Except for one isolate, all were genotypic and phenotypically MDR, and five of them also harbored cephalosporin resistance genes (blaCTX–M–14, blaSHV–12, and three blaCMY–2). mcr-1 genes were mobilizable by conjugation, associated with IncX4, IncHI2, and IncI2 plasmids. In our study, mcr-1 genes have been circulating in pig farms since 2005 harbored by a variety of E. coli clones. Its persistence may be driven by co-selection since plasmids containing mcr-1 also exhibit resistance to multiple drugs used in veterinary medicine. Furthermore, this is the first report of the presence of mcr-1 gene in isolates from white storks in Spain. This finding highlights the potential importance of wildlife that forage at urban household waste landfills in the transmission and spread of colistin resistance genes.
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Affiliation(s)
- Lourdes Migura-Garcia
- Centre de Recerca en Sanitat Animal, Institut de Recerca i Tecnologia Agroalimentàries, Barcelona, Spain.,Research and Control of Emerging and Re-emerging Swine Diseases in Europe, OIE Collaborating Centre, CReSA, IRTA, Barcelona, Spain
| | - Juan J González-López
- Servei de Microbiologia, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Jaime Martinez-Urtaza
- Centre for Environment, Fisheries and Aquaculture Science (CEFAS), Weymouth, United Kingdom
| | - J R Aguirre Sánchez
- Centro de Investigación en Alimentación y Desarrollo, Culiacán, Mexico.,Health and Biotechnology (SaBio) Group, Instituto de Investigación en Recursos Cinégéticos IREC (CSIC-UCLM-JCCM), Ciudad Real, Spain
| | - A Moreno-Mingorance
- Servei de Microbiologia, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - A Perez de Rozas
- Centre de Recerca en Sanitat Animal, Institut de Recerca i Tecnologia Agroalimentàries, Barcelona, Spain
| | - Ursula Höfle
- Health and Biotechnology (SaBio) Group, Instituto de Investigación en Recursos Cinégéticos IREC (CSIC-UCLM-JCCM), Ciudad Real, Spain
| | - Y Ramiro
- Health and Biotechnology (SaBio) Group, Instituto de Investigación en Recursos Cinégéticos IREC (CSIC-UCLM-JCCM), Ciudad Real, Spain
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19
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Analysis of virulence potential of Escherichia coli O145 isolated from cattle feces and hide samples based on whole genome sequencing. PLoS One 2019; 14:e0225057. [PMID: 31774847 PMCID: PMC6881001 DOI: 10.1371/journal.pone.0225057] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 10/28/2019] [Indexed: 12/29/2022] Open
Abstract
Escherichia coli O145 serogroup is one of the big six non-O157 Shiga toxin producing E. coli (STEC) that causes foodborne illnesses in the United States and other countries. Cattle are a major reservoir of STEC, which harbor them in their hindgut and shed in the feces. Cattle feces is the main source of hide and subsequent carcass contaminations during harvest leading to foodborne illnesses in humans. The objective of our study was to determine the virulence potential of STEC O145 strains isolated from cattle feces and hide samples. A total of 71 STEC O145 strains isolated from cattle feces (n = 16), hide (n = 53), and human clinical samples (n = 2) were used in the study. The strains were subjected to whole genome sequencing using Illumina MiSeq platform. The average draft genome size of the fecal, hide, and human clinical strains were 5.41, 5.28, and 5.29 Mb, respectively. The average number of genes associated with mobile genetic elements was 260, 238, and 259, in cattle fecal, hide, and human clinical strains, respectively. All strains belonged to O145:H28 serotype and carried eae subtype γ. Shiga toxin 1a was the most common Shiga toxin gene subtype among the strains, followed by stx2a and stx2c. The strains also carried genes encoding type III secretory system proteins, nle, and plasmid-encoded virulence genes. Phylogenetic analysis revealed clustering of cattle fecal strains separately from hide strains, and the human clinical strains were more closely related to the hide strains. All the strains belonged to sequence type (ST)-32. The virulence gene profile of STEC O145 strains isolated from cattle sources was similar to that of human clinical strains and were phylogenetically closely related to human clinical strains. The genetic analysis suggests the potential of cattle STEC O145 strains to cause human illnesses. Inclusion of more strains from cattle and their environment in the analysis will help in further elucidation of the genetic diversity and virulence potential of cattle O145 strains.
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González-Escalona N, Allard MA, Brown EW, Sharma S, Hoffmann M. Nanopore sequencing for fast determination of plasmids, phages, virulence markers, and antimicrobial resistance genes in Shiga toxin-producing Escherichia coli. PLoS One 2019; 14:e0220494. [PMID: 31361781 PMCID: PMC6667211 DOI: 10.1371/journal.pone.0220494] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 07/17/2019] [Indexed: 02/02/2023] Open
Abstract
Whole genome sequencing can provide essential public health information. However, it is now known that widely used short-read methods have the potential to miss some randomly-distributed segments of genomes. This can prevent phages, plasmids, and virulence factors from being detected or properly identified. Here, we compared assemblies of three complete Shiga toxin-producing Escherichia coli (STEC) O26:H11/H- genomes from two different sequence types (ST21 and 29), each acquired using the Nextera XT MiSeq, MinION nanopore-based sequencing, and Pacific Biosciences (PacBio) sequencing. Each closed genome consisted of a single chromosome, approximately 5.7 Mb for CFSAN027343, 5.6 Mb for CFSAN027346, and 5.4 MB for CFSAN027350. However, short-read whole genome sequencing (WGS) using Nextera XT MiSeq failed to identify some virulence genes in plasmids and on the chromosome, both of which were detected using the long-read platforms. Results from long-read MinION and PacBio allowed us to identify differences in plasmid content: a single 88 kb plasmid in CFSAN027343; a 157kb plasmid in CFSAN027350; and two plasmids in CFSAN027346 (one 95 Kb, one 72 Kb). These data enabled rapid characterization of the virulome, detection of antimicrobial genes, and composition/location of Stx phages. Taken together, positive correlations between the two long-read methods for determining plasmids, virulome, antimicrobial resistance genes, and phage composition support MinION sequencing as one accurate and economical option for closing STEC genomes and identifying specific virulence markers.
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Affiliation(s)
- Narjol González-Escalona
- Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD, United States of America
- * E-mail:
| | - Marc A. Allard
- Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD, United States of America
| | - Eric W. Brown
- Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD, United States of America
| | - Shashi Sharma
- Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD, United States of America
| | - Maria Hoffmann
- Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD, United States of America
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van Hoek AHAM, van Veldhuizen JNJ, Friesema I, Coipan C, Rossen JWA, Bergval IL, Franz E. Comparative genomics reveals a lack of evidence for pigeons as a main source of stx 2f-carrying Escherichia coli causing disease in humans and the common existence of hybrid Shiga toxin-producing and enteropathogenic E. coli pathotypes. BMC Genomics 2019; 20:271. [PMID: 30953471 PMCID: PMC6451237 DOI: 10.1186/s12864-019-5635-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 03/21/2019] [Indexed: 12/13/2022] Open
Abstract
Background Wild birds, in particular pigeons are considered a natural reservoir for stx2f-carrying E. coli. An extensive comparison of isolates from pigeons and humans from the same region is lacking, which hampers justifiable conclusions on the epidemiology of these pathogens. Over two hundred human and pigeon stx2f-carrying E. coli isolates predominantly from the Netherlands were analysed by whole genome sequencing and comparative genomic analysis including in silico MLST, serotyping, virulence genes typing and whole genome MLST (wgMLST). Results Serotypes and sequence types of stx2f-carrying E. coli showed a strong non-random distribution among the human and pigeon isolates with O63:H6/ST583, O113:H6/ST121 and O125:H6/ST583 overrepresented among the human isolates and not found among pigeons. Pigeon isolates were characterized by an overrepresentation of O4:H2/ST20 and O45:H2/ST20. Nearly all isolates harboured the locus of enterocyte effacement (LEE) but different eae and tir subtypes were non-randomly distributed among human and pigeon isolates. Phylogenetic core genome comparison demonstrated that the pigeon isolates and clinical isolates largely occurred in separated clusters. In addition, serotypes/STs exclusively found among humans generally were characterized by high level of clonality, smaller genome sizes and lack of several non-LEE-encoded virulence genes. A bundle-forming pilus operon, including bfpA, indicative for typical enteropathogenic E. coli (tEPEC) was demonstrated in 72.0% of the stx2f-carrying serotypes but with distinct operon types between the main pigeon and human isolate clusters. Conclusions Comparative genomics revealed that isolates from mild human disease are dominated by serotypes not encountered in the pigeon reservoir. It is therefore unlikely that zoonotic transmission from this reservoir plays an important role in the contribution to the majority of human disease associated with stx2f-producing E. coli in the Netherlands. Unexpectedly, this study identified the common occurrence of STEC2f/tEPEC hybrid pathotype in various serotypes and STs. Further research should focus on the possible role of human-to-human transmission of Stx2f-producing E. coli. Electronic supplementary material The online version of this article (10.1186/s12864-019-5635-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Angela H A M van Hoek
- Centre for Infectious Disease Control (CIb), National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands.
| | - Janieke N J van Veldhuizen
- Centre for Infectious Disease Control (CIb), National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands
| | - Ingrid Friesema
- Centre for Infectious Disease Control (CIb), National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands
| | - Claudia Coipan
- Centre for Infectious Disease Control (CIb), National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands
| | - John W A Rossen
- Department of Medical Microbiology and Infection Prevention, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Indra L Bergval
- Centre for Infectious Disease Control (CIb), National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands
| | - Eelco Franz
- Centre for Infectious Disease Control (CIb), National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands
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Complete Genome Sequences of Two Atypical Enteropathogenic Escherichia coli O145 Environmental Strains. GENOME ANNOUNCEMENTS 2018; 6:6/19/e00418-18. [PMID: 29748413 PMCID: PMC5946043 DOI: 10.1128/genomea.00418-18] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Escherichia coli O145 strains RM14715 and RM14723 were isolated from wildlife feces near a leafy greens-growing region in Yuma, Arizona. Both strains carry a distinct genotype compared with the E. coli O145 strains isolated from Salinas Valley, California. Here we report complete genome sequences and annotations of RM14715 and RM14723.
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Complete Genome Sequence of a Natural Escherichia coli O145:H11 Isolate That Belongs to Phylogroup A. GENOME ANNOUNCEMENTS 2018; 6:6/16/e00349-18. [PMID: 29674560 PMCID: PMC5908948 DOI: 10.1128/genomea.00349-18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Escherichia coli O145:H11 strain RM14721 was originally isolated from wildlife feces near a leafy greens-growing region in Yuma, AZ. This strain was initially positive for stx1; however, in subsequent cultures, stx1 was not detected by PCR. Here, we report the complete genome sequence and annotation of RM14721.
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