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Kudva IT, Biernbaum EN, Cassmann ED, Palmer MV. Bovine Rectoanal Junction In Vitro Organ Culture Model System to Study Shiga Toxin-Producing Escherichia coli Adherence. Microorganisms 2023; 11:1289. [PMID: 37317263 DOI: 10.3390/microorganisms11051289] [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: 04/14/2023] [Revised: 04/27/2023] [Accepted: 05/06/2023] [Indexed: 06/16/2023] Open
Abstract
Studies evaluating the interactions between Shiga toxin-producing Escherichia coli O157:H7 (O157) and the bovine recto-anal junction (RAJ) have been limited to either in vitro analyses of bacteria, cells, or nucleic acids at the RAJ, providing limited information. Alternatively, expensive in vivo studies in animals have been conducted. Therefore, our objective was to develop a comprehensive in vitro organ culture system of the RAJ (RAJ-IVOC) that accurately represents all cell types present in the RAJ. This system would enable studies that yield results similar to those observed in vivo. Pieces of RAJ tissue, obtained from unrelated cattle necropsies, were assembled and subjected to various tests in order to determine the optimal conditions for assaying bacterial adherence in a viable IVOC. O157 strain EDL933 and E. coli K12 with known adherence differences were used to standardize the RAJ-IVOC adherence assay. Tissue integrity was assessed using cell viability, structural cell markers, and histopathology, while the adherence of bacteria was evaluated via microscopy and culture methods. DNA fingerprinting verified the recovered bacteria against the inoculum. When the RAJ-IVOC was assembled in Dulbecco's Modified Eagle Medium, maintained at a temperature of 39 °C with 5% CO2 and gentle shaking for a duration of 3-4 h, it successfully preserved tissue integrity and reproduced the expected adherence phenotype of the bacteria being tested. The RAJ-IVOC model system provides a convenient method to pre-screen multiple bacteria-RAJ interactions prior to in vivo experiments, thereby reducing animal usage.
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Affiliation(s)
- Indira T Kudva
- Food Safety and Enteric Pathogens Research Unit, National Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Ames, IA 50010, USA
| | - Erika N Biernbaum
- Food Safety and Enteric Pathogens Research Unit, National Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Ames, IA 50010, USA
- Oak Ridge Institute for Science and Education, Oak Ridge, TN 37830, USA
| | - Eric D Cassmann
- Virus and Prion Research Unit, National Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Ames, IA 50010, USA
| | - Mitchell V Palmer
- Infectious Bacterial Diseases Research Unit, National Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Ames, IA 50010, USA
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Escherichia coli 0157:H7 virulence factors and the ruminant reservoir. Curr Opin Infect Dis 2022; 35:205-214. [PMID: 35665714 PMCID: PMC9302714 DOI: 10.1097/qco.0000000000000834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW This review updates recent findings about Escherichia coli O157:H7 virulence factors and its bovine reservoir. This Shiga toxin (Stx)-producing E. coli belongs to the Enterohemorrhagic E. coli (EHEC) pathotype causing hemorrhagic colitis. Its low infectious dose makes it an efficient, severe, foodborne pathogen. Although EHEC remains in the intestine, Stx can translocate systemically and is cytotoxic to microvascular endothelial cells, especially in the kidney and brain. Disease can progress to life-threatening hemolytic uremic syndrome (HUS) with hemolytic anemia, acute kidney failure, and thrombocytopenia. Young children, the immunocompromised, and the elderly are at the highest risk for HUS. Healthy ruminants are the major reservoir of EHEC and cattle are the primary source of human exposure. RECENT FINDINGS Advances in understanding E. coli O157:H7 pathogenesis include molecular mechanisms of virulence, bacterial adherence, type three secretion effectors, intestinal microbiome, inflammation, and reservoir maintenance. SUMMARY Many aspects of E. coli O157:H7 disease remain unclear and include the role of the human and bovine intestinal microbiomes in infection. Therapeutic strategies involve controlling inflammatory responses and/or intestinal barrier function. Finally, elimination/reduction of E. coli O157:H7 in cattle using CRISPR-engineered conjugative bacterial plasmids and/or on-farm management likely hold solutions to reduce infections and increase food safety/security.
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S. Hoefler R, Kudva IT. EDL933 Strains of Escherichia coli O157 can Demonstrate Genetic Diversity and Differential Adherence to Bovine Recto-Anal Junction Squamous Epithelial Cells. Open Microbiol J 2021. [DOI: 10.2174/1874285802115010129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Background:
Differences between Escherichia coli O157 (O157) strains are well-established with some of these strains being associated with major outbreaks in the US. EDL933 is one such O157 strain that caused a multistate outbreak in 1982 and has since been used as a prototype in various O157-related experiments.
Objective:
As O157 can readily acquire genetic mutations, we sought to determine if the genetic and phenotypic profiles of EDL933 strains from different sources would be consistent.
Methods:
We evaluated wild-type O157 strains stocked as EDL933 from three different laboratories, in the strain typing Polymorphic Amplified Typing Sequence (PATS) and the bovine rectal-anal junction squamous epithelial (RSE) cell- and HEp-2 cell- adherence assays. In addition, we also verified if Shiga toxins (Stx), the Locus of Enterocyte Effacement (LEE) or curli fimbriae contributed to the adherence phenotypes observed using mutant and wild-type EDL933 isolates.
Results:
Our results showed differences in PATS profiles and RSE cell-adherence phenotype, with no influence from the Stx or LEE genes, between EDL933 from different sources. Interestingly, the EDL933 strain that demonstrated the most contrasting diffuse adherence phenotype on RSE cells, EDL933-T, had decreased curli production that may have contributed to this phenotype.
Conclusion:
Our observations suggest that a comprehensive characterization of bacterial isolates, even if assigned to the same strain type prior to use in experiments, is warranted to ensure consistency and reproducibility of results.
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Mucosal IFNγ production and potential role in protection in Escherichia coli O157:H7 vaccinated and challenged cattle. Sci Rep 2021; 11:9769. [PMID: 33963240 PMCID: PMC8105325 DOI: 10.1038/s41598-021-89113-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 04/15/2021] [Indexed: 11/16/2022] Open
Abstract
Shiga-toxin producing Escherichia coli O157:H7 (O157)-based vaccines can provide a potential intervention strategy to limit foodborne zoonotic transmission of O157. While the peripheral antibody response to O157 vaccination has been characterized, O157-specific cellular immunity at the rectoanal junction (RAJ), a preferred site for O157 colonization, remains poorly described. Vaccine induced mucosal O157-specific antibodies likely provide some protection, cellular immune responses at the RAJ may also play a role in protection. Distinct lymphoid follicles were increased in the RAJ of vaccinated/challenged animals. Additionally, increased numbers of interferon (IFN)γ-producing cells and γδ + T cells were detected in the follicular region of the RAJ of vaccinated/challenged animals. Likewise, adjuvanted-vaccine formulation is critical in immunogenicity of the O157 parenteral vaccine. Local T cell produced IFNγ may impact epithelial cells, subsequently limiting O157 adherence, which was demonstrated using in vitro attachment assays with bovine epithelial cells. Thus, distinct immune changes induced at the mucosa of vaccinated and challenged animals provide insight of mechanisms associated with limiting O157 fecal shedding. Enhancing mucosal immunity may be critical in the further development of efficacious vaccines for controlling O157 in ruminants and thus limiting O157 transmission to humans.
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Katani R, Kudva IT, Srinivasan S, Stasko JB, Schilling M, Li L, Cote R, DebRoy C, Arthur TM, Sokurenko EV, Kapur V. Strain and host-cell dependent role of type-1 fimbriae in the adherence phenotype of super-shed Escherichia coli O157:H7. Int J Med Microbiol 2021; 311:151511. [PMID: 33975122 PMCID: PMC8605689 DOI: 10.1016/j.ijmm.2021.151511] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 04/14/2021] [Accepted: 05/03/2021] [Indexed: 02/04/2023] Open
Abstract
Super-shed (SS) Escherichia coli O157 (E. coli O157) demonstrate a strong, aggregative, locus of enterocyte effacement (LEE)-independent adherence phenotype on bovine recto-anal junction squamous epithelial (RSE) cells, and harbor polymorphisms in non-LEE-adherence-related loci, including in the type 1 fimbriae operon. To elucidate the role of type 1 fimbriae in strain- and host-specific adherence, we evaluated the entire Fim operon (FimB-H) and its adhesion (FimH) deletion mutants in four E. coli O157 strains, SS17, SS52, SS77 and EDL933, and evaluated the adherence phenotype in bovine RSE and human HEp-2 adherence assays. Consistent with the prevailing dogma that fimH expression is genetically switched off in E. coli O157, the ΔfimHSS52, ΔfimB-HSS52, ΔfimB-HSS17, and ΔfimHSS77 mutants remained unchanged in adherence phenotype to RSE cells. In contrast, the ΔfimHSS17 and ΔfimB-HSS77 mutants changed from a wild-type strong and aggregative, to a moderate and diffuse adherence phenotype, while both ΔfimHEDL933 and ΔfimB-HEDL933 mutants demonstrated enhanced binding to RSE cells (p < 0.05). Additionally, both ΔfimHSS17 and ΔfimHEDL933 were non-adherent to HEp-2 cells (p < 0.05). Complementation of the mutant strains with their respective wild-type genes restored parental phenotypes. Microscopy revealed that the SS17 and EDL933 strains indeed carry type 1 fimbriae-like structures shorter than those seen in uropathogenic E. coli. Taken together, these results provide compelling evidence for a strain and host cell type-dependent role of fimH and the fim operon in E. coli O157 adherence that needs to be further evaluated.
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Affiliation(s)
- Robab Katani
- The Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, USA
| | - Indira T Kudva
- Food Safety and Enteric Pathogens Research Unit, National Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Ames, IA, USA.
| | - Sreenidhi Srinivasan
- The Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, USA
| | - Judith B Stasko
- Microscopy Services, National Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Ames, IA, USA
| | - Megan Schilling
- The Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, USA
| | - Lingling Li
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, PA, USA
| | - Rebecca Cote
- The Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, USA
| | - Chitrita DebRoy
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, PA, USA
| | - Terrance M Arthur
- Roman L. Hruska U.S. Meat Animal Research Center, Agricultural Research Service, U.S. Department of Agriculture, Clay Center, NE, USA
| | | | - Vivek Kapur
- The Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, USA; Department of Animal Science, The Pennsylvania State University, University Park, PA, USA.
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Nonfimbrial Adhesin Mutants Reveal Divergent Escherichia coli O157:H7 Adherence Mechanisms on Human and Cattle Epithelial Cells. Int J Microbiol 2021; 2021:8868151. [PMID: 33574851 PMCID: PMC7864753 DOI: 10.1155/2021/8868151] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Accepted: 01/08/2021] [Indexed: 11/17/2022] Open
Abstract
Shiga toxin-producing, enterohemorrhagic Escherichia coli (EHEC) serotype O157:H7 is a major foodborne pathogen causing symptoms ranging from simple intestinal discomfort to bloody diarrhea and life-threatening hemolytic uremic syndrome in humans. Cattle can be asymptomatically colonized by O157:H7 predominantly at the rectoanal junction (RAJ). Colonization of the RAJ is highly associated with the shedding of O157:H7 in bovine feces. Supershedding (SS) is a phenomenon that has been reported in some cattle that shed more than 104 colony-forming units of O57:H7 per gram of feces, 100–1000 times more or greater than normal shedders. The unique bovine RAJ cell adherence model revealed that O157:H7 employs a LEE-independent mechanism of attachment to one of the RAJ cell types, the squamous epithelial (RSE) cells. Nine nonfimbrial adhesins were selected to determine their role in the characteristic hyperadherent phenotype of SS O157 on bovine RSE cells, in comparison with human HEp-2 cells. A number of single nucleotide polymorphisms (SNPs) were found amongst these nonfimbrial adhesins across a number of SS isolates. In human cells, deletion of yfaL reduced the adherence of both EDL933 and SS17. However, deletion of eae resulted in a significant loss of adherence in SS17 whereas deletion of wzzB and iha in EDL933 resulted in the same loss of adherence to HEp-2 cells. On RSE cells, none of these nonfimbrial deletion mutants were able to alter the adherence phenotype of SS17. In EDL933, deletion of cah resulted in mitigated adherence. Surprisingly, four nonfimbrial adhesin gene deletions were actually able to confer the hyperadherent phenotype on RSE cells. Overall, this study reveals that the contribution of nonfimbrial adhesins to the adherence mechanisms and functions of O157:H7 is both strain and host cell type dependent as well as indicates a possible role of these nonfimbrial adhesins in the SS phenotype exhibited on RSE cells.
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Cadona JS, Burgán J, González J, Bustamante AV, Sanso AM. Differential expression of the virulence gene nleB among Shiga toxin-producing Escherichia coli strains. Heliyon 2020; 6:e04277. [PMID: 32613131 PMCID: PMC7322132 DOI: 10.1016/j.heliyon.2020.e04277] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 05/08/2020] [Accepted: 06/18/2020] [Indexed: 11/22/2022] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) is a zoonotic foodborne pathogen associated with hemolytic uremic syndrome (HUS) that vary in their ability to cause disease in humans. STEC represents a serious problem for public health and Argentina is the country with the highest HUS incidence worldwide. Non-LEE effector (nle) genes, present on pathogenicity islands (PAIs), encode translocated substrates of the type III secretion system (T3SS), which could have an important role in STEC virulence. Particularly, nleB is one of the main effector genes proposed as a virulence marker that is involved in the action of T3SS during the STEC infection. NleB inhibits the inflammatory response of the host cell allowing the bacteria to persist in the first stage of the infection. In order to identify the potential risk of STEC strains for public health, the aim of this study was to evaluate and compare basal nleB transcription of 24 STEC strains belonging to 10 serotypes isolated from cattle, food and patients. The results showed differences in nleB transcription among strains. Some non-O157:H7 strains presented transcription levels above the control, an O157:H7 HUS-producing strain. On the other hand, no significant differences were found in basal transcription levels associated with origin or serotype but differences were found between HUS and non-HUS strains. These differences in nleB transcription may be of importance in STEC pathogenesis and could help to differentiate high and low virulence STEC strains.
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Sapountzis P, Segura A, Desvaux M, Forano E. An Overview of the Elusive Passenger in the Gastrointestinal Tract of Cattle: The Shiga Toxin Producing Escherichia coli. Microorganisms 2020; 8:microorganisms8060877. [PMID: 32531983 PMCID: PMC7355788 DOI: 10.3390/microorganisms8060877] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 06/05/2020] [Accepted: 06/07/2020] [Indexed: 02/07/2023] Open
Abstract
For approximately 10,000 years, cattle have been our major source of meat and dairy. However, cattle are also a major reservoir for dangerous foodborne pathogens that belong to the Shiga toxin-producing Escherichia coli (STEC) group. Even though STEC infections in humans are rare, they are often lethal, as treatment options are limited. In cattle, STEC infections are typically asymptomatic and STEC is able to survive and persist in the cattle GIT by escaping the immune defenses of the host. Interactions with members of the native gut microbiota can favor or inhibit its persistence in cattle, but research in this direction is still in its infancy. Diet, temperature and season but also industrialized animal husbandry practices have a profound effect on STEC prevalence and the native gut microbiota composition. Thus, exploring the native cattle gut microbiota in depth, its interactions with STEC and the factors that affect them could offer viable solutions against STEC carriage in cattle.
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Affiliation(s)
- Panagiotis Sapountzis
- Université Clermont Auvergne, INRAE, UMR 0454 MEDIS, 63000 Clermont-Ferrand, France; (A.S.); (M.D.); (E.F.)
- Correspondence:
| | - Audrey Segura
- Université Clermont Auvergne, INRAE, UMR 0454 MEDIS, 63000 Clermont-Ferrand, France; (A.S.); (M.D.); (E.F.)
- Chr. Hansen Animal Health & Nutrition, 2970 Hørsholm, Denmark
| | - Mickaël Desvaux
- Université Clermont Auvergne, INRAE, UMR 0454 MEDIS, 63000 Clermont-Ferrand, France; (A.S.); (M.D.); (E.F.)
| | - Evelyne Forano
- Université Clermont Auvergne, INRAE, UMR 0454 MEDIS, 63000 Clermont-Ferrand, France; (A.S.); (M.D.); (E.F.)
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Supershed Escherichia coli O157:H7 Has Potential for Increased Persistence on the Rectoanal Junction Squamous Epithelial Cells and Antibiotic Resistance. Int J Microbiol 2020; 2020:2368154. [PMID: 32351572 PMCID: PMC7178529 DOI: 10.1155/2020/2368154] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 02/24/2020] [Accepted: 03/17/2020] [Indexed: 11/18/2022] Open
Abstract
Supershedding cattle shed Escherichia coli O157:H7 (O157) at ≥ 104 colony-forming units/g feces. We recently demonstrated that a supershed O157 (SS-O157) strain, SS-17, hyperadheres to the rectoanal junction (RAJ) squamous epithelial (RSE) cells which may contribute to SS-O157 persistence at this site in greater numbers, thereby increasing the fecal O157 load characterizing the supershedding phenomenon. In order to verify if this would be the signature adherence profile of any SS-O157, we tested additional SS-O157 isolates (n = 101; each from a different animal) in the RSE cell adherence assay. Similar to SS-17, all 101 SS-O157 exhibited aggregative adherence on RSE cells, with 56% attaching strongly (>10 bacteria/cell; hyperadherent) and 44% attaching moderately (1–10 bacteria/cells). Strain typing using Polymorphic Amplified Typing Sequences (PATS) analysis assigned the 101 SS-O157 into 5 major clades but not to any predominant genotype. Interestingly, 69% of SS-O157 isolates were identical to human O157 outbreak strains based on pulsed field gel electrophoresis profiles (CDC PulseNet Database), grouped into two clades by PATS distinguishing them from remaining SS-O157, and were hyperadherent on RSE cells. A subset of SS-O157 isolates (n = 53) representing different PATS and RSE cell adherence profiles were analyzed for antibiotic resistance (AR). Several SS-O157 (30/53) showed resistance to sulfisoxazole, and one isolate was resistant to both sulfisoxazole and tetracycline. Minimum inhibitory concentration (MIC) tests confirmed some of the resistance observed using the Kirby–Bauer disk diffusion test. Each SS-O157 isolate carried at least 10 genes associated with AR. However, genes directly associated with AR were rarely amplified: aac (3)-IV in 2 isolates, sul2 in 3 isolates, and tetB in one isolate. The integrase gene, int, linked with integron-based AR acquisition/transmission, was identified in 92% of SS-O157 isolates. Our results indicate that SS-O157 isolates could potentially persist longer at the bovine RAJ but exhibit limited resistance towards clinical antibiotics.
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Response to Questions Posed by the Food and Drug Administration Regarding Virulence Factors and Attributes that Define Foodborne Shiga Toxin-Producing Escherichia coli (STEC) as Severe Human Pathogens †. J Food Prot 2019; 82:724-767. [PMID: 30969806 DOI: 10.4315/0362-028x.jfp-18-479] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
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- NACMCF Executive Secretariat, * U.S. Department of Agriculture, Food Safety and Inspection Service, Office of Public Health Science, PP3, 9-178, 1400 Independence Avenue S.W., Washington, D.C. 20250-3700, USA
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Da Silva WM, Bei J, Amigo N, Valacco MP, Amadio A, Zhang Q, Wu X, Yu T, Larzabal M, Chen Z, Cataldi A. Quantification of enterohemorrhagic Escherichia coli O157:H7 protein abundance by high-throughput proteome. PLoS One 2018; 13:e0208520. [PMID: 30596662 PMCID: PMC6312284 DOI: 10.1371/journal.pone.0208520] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 11/19/2018] [Indexed: 12/22/2022] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is a human pathogen responsible for diarrhea, hemorrhagic colitis and hemolytic uremic syndrome (HUS). To promote a comprehensive insight into the molecular basis of EHEC O157:H7 physiology and pathogenesis, the combined proteome of EHEC O157:H7 strains, Clade 8 and Clade 6 isolated from cattle in Argentina, and the standard EDL933 (clade 3) strain has been analyzed. From shotgun proteomic analysis a total of 2,644 non-redundant proteins of EHEC O157:H7 were identified, which correspond approximately 47% of the predicted proteome of this pathogen. Normalized spectrum abundance factor analysis was performed to estimate the protein abundance. According this analysis, 50 proteins were detected as the most abundant of EHEC O157:H7 proteome. COG analysis showed that the majority of the most abundant proteins are associated with translation processes. A KEGG enrichment analysis revealed that Glycolysis / Gluconeogenesis was the most significant pathway. On the other hand, the less abundant detected proteins are those related to DNA processes, cell respiration and prophage. Among the proteins that composed the Type III Secretion System, the most abundant protein was EspA. Altogether, the results show a subset of important proteins that contribute to physiology and pathogenicity of EHEC O157:H7.
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Affiliation(s)
- Wanderson Marques Da Silva
- Institute of Biotechnology, CICVyA, National Institute of Agricultural Technology, Hurlingham, Buenos Aires, Argentina
| | - Jinlong Bei
- AGRO-Biological Gene Research Center, Guangdong Academy of Agricultural Sciences (GDAAS), Guangzhou, China
| | - Natalia Amigo
- Institute of Biotechnology, CICVyA, National Institute of Agricultural Technology, Hurlingham, Buenos Aires, Argentina
| | - María Pía Valacco
- CEQUIBIEM (Mass Spectrometry Facility), Faculty of Exact and Natural Sciences, University of Buenos Aires and CONICET (National Research Council), Buenos Aires, Argentina
| | - Ariel Amadio
- Rafaela Experimental Station, National Institute of Agricultural Technology, Rafaela, Santa Fe, Argentina
| | - Qi Zhang
- AGRO-Biological Gene Research Center, Guangdong Academy of Agricultural Sciences (GDAAS), Guangzhou, China
| | - Xiuju Wu
- AGRO-Biological Gene Research Center, Guangdong Academy of Agricultural Sciences (GDAAS), Guangzhou, China
| | - Ting Yu
- AGRO-Biological Gene Research Center, Guangdong Academy of Agricultural Sciences (GDAAS), Guangzhou, China
| | - Mariano Larzabal
- Institute of Biotechnology, CICVyA, National Institute of Agricultural Technology, Hurlingham, Buenos Aires, Argentina
| | - Zhuang Chen
- AGRO-Biological Gene Research Center, Guangdong Academy of Agricultural Sciences (GDAAS), Guangzhou, China
| | - Angel Cataldi
- Institute of Biotechnology, CICVyA, National Institute of Agricultural Technology, Hurlingham, Buenos Aires, Argentina
- * E-mail:
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Martorelli L, Albanese A, Vilte D, Cantet R, Bentancor A, Zolezzi G, Chinen I, Ibarra C, Rivas M, Mercado EC, Cataldi A. Shiga toxin-producing Escherichia coli (STEC) O22:H8 isolated from cattle reduces E. coli O157:H7 adherence in vitro and in vivo. Vet Microbiol 2017; 208:8-17. [PMID: 28888654 DOI: 10.1016/j.vetmic.2017.06.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 06/28/2017] [Accepted: 06/28/2017] [Indexed: 01/05/2023]
Abstract
PROBLEM ADDRESSED Shiga toxin-producing Escherichia coli (STEC) are a group of bacteria responsible for food-associated diseases. Clinical features include a wide range of symptoms such as diarrhea, hemorrhagic colitis and the hemolytic uremic syndrome (HUS), a life-threatening condition. OBJECTIVE Our group has observed that animals naturally colonized with STEC strains of unknown serotype were not efficiently colonized with E. coli O157:H7 after experimental infection. In order to assess the basis of the interference, three STEC strains were isolated from STEC persistently-colonized healthy cattle from a dairy farm in Buenos Aires, Argentina. METHODS AND RESULTS The three isolated strains are E. coli O22:H8 and carry the stx1 and stx2d genes. The activatable activity of Stx2d was demonstrated in vitro. The three strains carry the adhesins iha, ehaA and lpfO113. E. coli O22:H8 formed stronger biofilms in abiotic surface than E. coli O157:H7 (eae+, stx2+) and displayed a more adherent phenotype in vitro towards HeLa cells. Furthermore, when both serotypes were cultured together O22:H8 could reduce O157:H7 adherence in vitro. When calves were intragastrically pre-challenged with 108 CFU of a mixture of the three STEC strains and two days later challenged with the same dose of the strain E. coli O157:H7 438/99, the shedding of the pathogen was significantly reduced. CONCLUSIONS These results suggest that E. coli O22:H8, a serotype rarely associated with human illness, might compete with O157:H7 at the bovine recto-anal junction, making non-O157 carrying-calves less susceptible to O157:H7 colonization and shedding of the bacteria to the environment.
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Affiliation(s)
- L Martorelli
- Instituto de Patobiología, CICVyA, Instituto Nacional de Tecnología Agropecuaria, Hurlingham 1686, Argentina
| | - A Albanese
- Laboratorio de Fisiopatogenia, Departamento de Fisiología, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO Houssay-CONICET), Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires 1121, Argentina
| | - D Vilte
- Instituto de Patobiología, CICVyA, Instituto Nacional de Tecnología Agropecuaria, Hurlingham 1686, Argentina
| | - R Cantet
- Facultad de Agronomía, Universidad de Buenos Aires-CONICET, Buenos Aires 1427, Argentina
| | - A Bentancor
- Cátedra de Microbiología, Facultad de Ciencias Veterinarias, Universidad de Buenos Aires, Buenos Aires 1427, Argentina
| | - G Zolezzi
- Servicio Fisiopatogenia, INEI-ANLIS "Dr. Carlos G. Malbrán", Buenos Aires 1282, Argentina
| | - I Chinen
- Servicio Fisiopatogenia, INEI-ANLIS "Dr. Carlos G. Malbrán", Buenos Aires 1282, Argentina
| | - C Ibarra
- Laboratorio de Fisiopatogenia, Departamento de Fisiología, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO Houssay-CONICET), Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires 1121, Argentina
| | - M Rivas
- Servicio Fisiopatogenia, INEI-ANLIS "Dr. Carlos G. Malbrán", Buenos Aires 1282, Argentina
| | - E C Mercado
- Instituto de Patobiología, CICVyA, Instituto Nacional de Tecnología Agropecuaria, Hurlingham 1686, Argentina
| | - A Cataldi
- Instituto de Biotecnología, CICVyA, Instituto Nacional de Tecnología Agropecuaria, Hurlingham 1686, Argentina.
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Cornick NA, Pitzer J, Helgerson AF, Madsen ML, Kurth KT, Xiao Q, Minion FC. Use of signature-tagged mutagenesis to identify genes associated with colonization of sheep by E. coli O157:H7. Vet Microbiol 2017; 201:177-182. [PMID: 28284606 DOI: 10.1016/j.vetmic.2017.01.031] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 01/24/2017] [Accepted: 01/27/2017] [Indexed: 10/20/2022]
Abstract
Outbreaks of Escherichia coli O157:H7 in the United States due to contaminated foods are a public health issue and a continuing problem. The major reservoir for these organisms is the gastrointestinal tract of ruminants where they are a member of the resident microbiota. Several factors that contribute to the colonization of cattle have been identified, but a systematic screen of genes that might contribute to the colonization and persistence phenotype in mature ruminants has not been reported. Using a sheep model of persistence, signature tagged mutagenesis (STM) was used to screen 1326 mutants for a persistence-negative phenotype of E. coli O157:H7. We identified 9 genes by STM that appeared to be required for colonization and/or survival in sheep. Three of the genes had functions associated with central metabolism (thiK, ftrA and nrdB), one was involved with LPS formation (wbdP), one encodes a non-LEE encoded effector protein (nleB) and one was a methyltransferase encoded on a prophage (Z2389). The remaining three genes did not have homology with any known genes. Six sheep given ΔwbdP and 2 sheep each were given mutants (ΔthiK (Z1745), ΔftrA (Z2164) and Z2389). The ΔwbdP mutant was recovered from the feces of 4/6 sheep at 6 days pi with a mean number of 1.42log10CFU/g feces compared to 4.6log10CFU/g feces for the wild type strain. This difference was significant (P<0.001) over the time course of the experiment (days 6-23). Both ΔthiK and ΔftrA mutants were recovered from 1 of 2 sheep at 9 days PI by enrichment procedures (<50CFU/g feces) whereas mutant Z2389 was not recovered from either animal past 2 days pi. The roles of all of these gene products require further study to determine how the persistence phenotype of a given strain of E. coli O157:H7 interacts with host factors.
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Affiliation(s)
- Nancy A Cornick
- Department of Veterinary Microbiology and Preventive Medicine, Iowa State University, Ames, IA, 50011, United States.
| | - Josh Pitzer
- Department of Veterinary Microbiology and Preventive Medicine, Iowa State University, Ames, IA, 50011, United States
| | - Amy F Helgerson
- Department of Veterinary Microbiology and Preventive Medicine, Iowa State University, Ames, IA, 50011, United States
| | - Melissa L Madsen
- Department of Veterinary Microbiology and Preventive Medicine, Iowa State University, Ames, IA, 50011, United States
| | - Kathy T Kurth
- Department of Veterinary Microbiology and Preventive Medicine, Iowa State University, Ames, IA, 50011, United States
| | - Qianjun Xiao
- Department of Veterinary Microbiology and Preventive Medicine, Iowa State University, Ames, IA, 50011, United States
| | - F Chris Minion
- Department of Veterinary Microbiology and Preventive Medicine, Iowa State University, Ames, IA, 50011, United States
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Martorelli L, Garbaccio S, Vilte DA, Albanese AA, Mejías MP, Palermo MS, Mercado EC, Ibarra CE, Cataldi AA. Immune Response in Calves Vaccinated with Type Three Secretion System Antigens and Shiga Toxin 2B Subunit of Escherichia coli O157:H7. PLoS One 2017; 12:e0169422. [PMID: 28046078 PMCID: PMC5207737 DOI: 10.1371/journal.pone.0169422] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2016] [Accepted: 12/17/2016] [Indexed: 12/03/2022] Open
Abstract
Ruminants are the primary reservoir of Shiga-toxin producing Escherichia coli (STEC) O157:H7 and the main source of infection for humans. The aim of this study was to assess the immunogenic properties of a candidate vaccine consisting on the recombinant proteins of E. coli O157:H7 IntiminC280, the carboxy-terminal fraction of Intimin γ, EspB and the fusion protein between the B subunit of Stx2 and Brucella Lumazine Synthase (BLS)(BLS-Stx2B), in Holstein Fresian calves.To accomplish this goal we vaccinated calves with two doses of different vaccine formulations: 2 antigens (IntiminC280, EspB), 3 antigens (IntiminC280, EspB, BLS-Stx2B), BLS-Stx2B alone and a control non-vaccinated group. All antigens were expressed as recombinant proteins in E. coli. Specific IgG titres increased in vaccinated calves and the inclusion of BLS-Stx2B in the formulation seems to have a stimulatory effect on the humoral response to IntiminC280 and EspB after the booster. The neutralizing activity of antibodies against these two antigens was assessed in Red Blood Cell lysis assays and adherence to Hep-2 cells as a correlate of T3SS activity. Both sera from animals vaccinated with 2 or 3 antigens inhibited both virulence properties. Serological response to Stx2 was observed in animals vaccinated only with BLS-Stx2B and with 3 antigens and neutralization of Stx2 cytotoxicity was also observed in both groups. In conclusion, immunization of calves with BLS-Stx2B, IntiminC280 and EspB elicited a potent humoral response able to neutralize Shiga toxin 2 cytotoxity and the T3SS virulence properties in vitro. These results suggest that this formulation is a good candidate vaccine to reduce STEC shedding in cattle and needs to be further assessed in vivo.
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Affiliation(s)
- Luisina Martorelli
- Instituto de Patobiología, Centro de Investigación en Ciencias Veterinarias y Agronómicas, Instituto Nacional de Tecnología Agropecuaria, Hurlingham, Argentina
| | - Sergio Garbaccio
- Instituto de Patobiología, Centro de Investigación en Ciencias Veterinarias y Agronómicas, Instituto Nacional de Tecnología Agropecuaria, Hurlingham, Argentina
| | - Daniel A. Vilte
- Instituto de Patobiología, Centro de Investigación en Ciencias Veterinarias y Agronómicas, Instituto Nacional de Tecnología Agropecuaria, Hurlingham, Argentina
| | - Adriana A. Albanese
- Laboratorio de Fisiopatogenia, Departamento de Fisiología, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - María P. Mejías
- Laboratorio de Patogénesis e Inmunología de Procesos Infecciosos, Instituto de Medicina Experimental, (IMEX), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)- Academia Nacional de Medicina, Buenos Aires, Argentina
| | - Marina S. Palermo
- Laboratorio de Patogénesis e Inmunología de Procesos Infecciosos, Instituto de Medicina Experimental, (IMEX), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)- Academia Nacional de Medicina, Buenos Aires, Argentina
| | - Elsa C. Mercado
- Instituto de Patobiología, Centro de Investigación en Ciencias Veterinarias y Agronómicas, Instituto Nacional de Tecnología Agropecuaria, Hurlingham, Argentina
| | - Cristina E. Ibarra
- Laboratorio de Fisiopatogenia, Departamento de Fisiología, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Angel A. Cataldi
- Instituto de Biotecnología, Centro de Investigación en Ciencias Veterinarias y Agronómicas, Instituto Nacional de Tecnología Agropecuaria, Hurlingham, Argentina
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15
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Kudva IT, Carter MQ, Sharma VK, Stasko JA, Giron JA. Curli Temper Adherence of Escherichia coli O157:H7 to Squamous Epithelial Cells from the Bovine Recto-Anal Junction in a Strain-Dependent Manner. Appl Environ Microbiol 2017; 83:e02594-16. [PMID: 27742683 PMCID: PMC5165118 DOI: 10.1128/aem.02594-16] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2016] [Accepted: 10/08/2016] [Indexed: 12/16/2022] Open
Abstract
Our recent studies have shown that intimin and the locus of enterocyte effacement-encoded proteins do not play a role in Escherichia coli O157:H7 (O157) adherence to the bovine recto-anal junction squamous epithelial (RSE) cells. To define factors that play a contributory role, we investigated the role of curli, fimbrial adhesins commonly implicated in adherence to various fomites and plant and human epithelial cells, in O157 adherence to RSE cells. Specifically, we examined (i) wild-type strains of O157; (ii) curli variants of O157 strains; (iii) isogenic curli deletion mutants of O157; and (iv) adherence inhibition of O157 using anti-curlin sera. Results of these experiments conducted under stringent conditions suggest that curli do not solely contribute to O157 adherence to RSE cells and in fact demonstrate a modulating effect on O157 adherence to RSE cells in contrast to HEp-2 cells (human epidermoid carcinoma of the larynx cells with HeLa contamination). The absence of curli and presence of blocking anti-curli antibodies enhanced O157-RSE cell interactions among some strains, thus alluding to a spatial, tempering effect of curli on O157 adherence to RSE cells when present. At the same time, the presence or absence of curli did not alter RSE cell adherence patterns of another O157 strain. These observations are at variance with the reported role of curli in O157 adherence to human cell lines such as HEp-2 and need to be factored in when developing anti-adherence modalities for preharvest control of O157 in cattle. IMPORTANCE This study demonstrated that O157 strains interact with epithelial cells in a host-specific manner. The fimbriae/adhesins that are significant for adherence to human cell lines may not have a role or may have a modulating role in O157 adherence to bovine cells. Targeting such adhesins may not prevent O157 attachment to bovine cells but instead may result in improved adherence. Hence, conducting host-specific evaluations is critical when selecting targets for O157 control strategies.
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Affiliation(s)
- Indira T Kudva
- Food Safety and Enteric Pathogens Research Unit, National Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Ames, Iowa, USA
| | - Michelle Q Carter
- Produce Safety and Microbiology Unit, Western Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, Albany, California, USA
| | - Vijay K Sharma
- Food Safety and Enteric Pathogens Research Unit, National Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Ames, Iowa, USA
| | - Judith A Stasko
- Microscopy Services Laboratory, National Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Ames, Iowa, USA
| | - Jorge A Giron
- Center for Biomolecular Detection, University of Puebla, Puebla, Mexico
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Stein R, Chirilã M. Routes of Transmission in the Food Chain. FOODBORNE DISEASES 2017. [PMCID: PMC7148622 DOI: 10.1016/b978-0-12-385007-2.00003-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
More than 250 different foodborne diseases have been described to date, annually affecting about one-third of the world's population. The incidence of foodborne diseases has been underreported and underestimated, and the asymptomatic presentation of some of the illnesses, worldwide heterogeneities in reporting, and the alternative transmission routes of certain pathogens are among the factors that contribute to this. Globalization, centralization of the food supply, transportation of food products progressively farther from their places of origin, and the multitude of steps where contamination may occur have made it increasingly challenging to investigate foodborne and waterborne outbreaks. Certain foodborne pathogens may be transmitted directly from animals to humans, while others are transmitted through vectors, such as insects, or through food handlers, contaminated food products or food-processing surfaces, or transfer from sponges, cloths, or utensils. Additionally, the airborne route may contribute to the transmission of certain foodborne pathogens. Complicating epidemiological investigations, multiple transmission routes have been described for some foodborne pathogens. Two types of transmission barriers, primary and secondary, have been described for foodborne pathogens, each of them providing opportunities for preventing and controlling outbreaks. Primary barriers, the most effective sites of prophylactic intervention, prevent pathogen entry into the environment, while secondary barriers prevent the multiplication and dissemination of pathogens that have already entered the environment. Understanding pathogen dynamics, monitoring transmission, and implementing preventive measures are complicated by the phenomenon of superspreading, which refers to the concept that, at the level of populations, a minority of hosts is responsible for the majority of transmission events.
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17
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The Locus of Enterocyte Effacement and Associated Virulence Factors of Enterohemorrhagic Escherichia coli. Microbiol Spectr 2016; 2:EHEC-0007-2013. [PMID: 26104209 DOI: 10.1128/microbiolspec.ehec-0007-2013] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A subset of Shiga toxin-producing Escherichia coli strains, termed enterohemorrhagic E. coli (EHEC), is defined in part by the ability to produce attaching and effacing (A/E) lesions on intestinal epithelia. Such lesions are characterized by intimate bacterial attachment to the apical surface of enterocytes, cytoskeletal rearrangements beneath adherent bacteria, and destruction of proximal microvilli. A/E lesion formation requires the locus of enterocyte effacement (LEE), which encodes a Type III secretion system that injects bacterial proteins into host cells. The translocated proteins, termed effectors, subvert a plethora of cellular pathways to the benefit of the pathogen, for example, by recruiting cytoskeletal proteins, disrupting epithelial barrier integrity, and interfering with the induction of inflammation, phagocytosis, and apoptosis. The LEE and selected effectors play pivotal roles in intestinal persistence and virulence of EHEC, and it is becoming clear that effectors may act in redundant, synergistic, and antagonistic ways during infection. Vaccines that target the function of the Type III secretion system limit colonization of reservoir hosts by EHEC and may thus aid control of zoonotic infections. Here we review the features and functions of the LEE-encoded Type III secretion system and associated effectors of E. coli O157:H7 and other Shiga toxin-producing E. coli strains.
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18
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Amigo N, Mercado E, Bentancor A, Singh P, Vilte D, Gerhardt E, Zotta E, Ibarra C, Manning SD, Larzábal M, Cataldi A. Clade 8 and Clade 6 Strains of Escherichia coli O157:H7 from Cattle in Argentina have Hypervirulent-Like Phenotypes. PLoS One 2015; 10:e0127710. [PMID: 26030198 PMCID: PMC4452545 DOI: 10.1371/journal.pone.0127710] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 04/17/2015] [Indexed: 12/27/2022] Open
Abstract
The hemolytic uremic syndrome (HUS) whose main causative agent is enterohemorrhagic Escherichia coli (EHEC) O157:H7 is a disease that mainly affects children under 5 years of age. Argentina is the country with the highest incidence of HUS in the world. Cattle are a major reservoir and source of infection with E. coli O157:H7. To date, the epidemiological factors that contribute to its prevalence are poorly understood. Single nucleotide polymorphism (SNP) typing has helped to define nine E. coli O157:H7 clades and the clade 8 strains were associated with most of the cases of severe disease. In this study, eight randomly selected isolates of EHEC O157:H7 from cattle in Argentina were studied as well as two human isolates. Four of them were classified as clade 8 through the screening for 23 SNPs; the two human isolates grouped in this clade as well, while two strains were closely related to strains representing clade 6. To assess the pathogenicity of these strains, we assayed correlates of virulence. Shiga toxin production was determined by an ELISA kit. Four strains were high producers and one of these strains that belonged to a novel genotype showed high verocytotoxic activity in cultured cells. Also, these clade 8 and 6 strains showed high RBC lysis and adherence to epithelial cells. One of the clade 6 strains showed stronger inhibition of normal water absorption than E. coli O157:H7 EDL933 in human colonic explants. In addition, two of the strains showing high levels of Stx2 production and RBC lysis activity were associated with lethality and uremia in a mouse model. Consequently, circulation of such strains in cattle may partially contribute to the high incidence of HUS in Argentina.
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Affiliation(s)
- Natalia Amigo
- Instituto de Biotecnología, CICVyA, Instituto Nacional de Tecnología Agropecuaria, Hurlingham, Argentina
| | - Elsa Mercado
- Instituto de Patobiologia, CICVyA, Instituto Nacional de Tecnología Agropecuaria, Hurlingham, Argentina
| | - Adriana Bentancor
- Microbiología, Facultad de Ciencias Veterinarias, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Pallavi Singh
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, United States of America
| | - Daniel Vilte
- Instituto de Patobiologia, CICVyA, Instituto Nacional de Tecnología Agropecuaria, Hurlingham, Argentina
| | - Elisabeth Gerhardt
- Departamento de Fisiología, IFIBIO-CONICET, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Elsa Zotta
- Departamento de Fisiología, IFIBIO-CONICET, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Cristina Ibarra
- Departamento de Fisiología, IFIBIO-CONICET, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Shannon D. Manning
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, United States of America
| | - Mariano Larzábal
- Instituto de Biotecnología, CICVyA, Instituto Nacional de Tecnología Agropecuaria, Hurlingham, Argentina
| | - Angel Cataldi
- Instituto de Biotecnología, CICVyA, Instituto Nacional de Tecnología Agropecuaria, Hurlingham, Argentina
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Kudva IT, Krastins B, Torres AG, Griffin RW, Sheng H, Sarracino DA, Hovde CJ, Calderwood SB, John M. The Escherichia coli O157:H7 cattle immunoproteome includes outer membrane protein A (OmpA), a modulator of adherence to bovine rectoanal junction squamous epithelial (RSE) cells. Proteomics 2015; 15:1829-42. [PMID: 25643951 PMCID: PMC4456246 DOI: 10.1002/pmic.201400432] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2014] [Revised: 11/18/2014] [Accepted: 01/20/2015] [Indexed: 12/20/2022]
Abstract
Building on previous studies, we defined the repertoire of proteins comprising the immunoproteome (IP) of Escherichia coli O157:H7 (O157) cultured in DMEM supplemented with norepinephrine (O157 IP), a β-adrenergic hormone that regulates E. coli O157 gene expression in the gastrointestinal tract, using a variation of a novel proteomics-based platform proteome mining tool for antigen discovery, called "proteomics-based expression library screening" (PELS; Kudva et al., 2006). The E. coli O157 IP (O157-IP) comprised 91 proteins, and included those identified previously using proteomics-based expression library screening, and also proteins comprising DMEM and bovine rumen fluid proteomes. Outer membrane protein A (OmpA), a common component of the above proteomes, and reportedly a contributor to E. coli O157 adherence to cultured HEp-2 epithelial cells, was interestingly found to be a modulator rather than a contributor to E. coli O157 adherence to bovine rectoanal junction squamous epithelial cells. Our results point to a role for yet to be identified members of the O157-IP in E. coli O157 adherence to rectoanal junction squamous epithelial cells, and additionally implicate a possible role for the outer membrane protein A regulator, TdcA, in the expression of such adhesins. Our observations have implications for the development of efficacious vaccines for preventing E. coli O157 colonization of the bovine gastrointestinal tract.
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Affiliation(s)
- Indira T. Kudva
- Food Safety and Enteric Pathogens Research Unit National Animal Disease Center Agricultural Research Service U.S. Department of Agriculture Ames, Iowa. 50010
| | - Bryan Krastins
- Harvard Partners Center For Genetics and Genomics 65 Landsdowne Street Cambridge, Massachusetts 02139
| | - Alfredo G. Torres
- Departments of Microbiology and Immunology, and Pathology University of Texas Medical Branch Galveston, Texas 77555-1070
| | - Robert W. Griffin
- Division of Infectious Diseases Massachusetts General Hospital Boston, Massachusetts 02114
| | - Haiqing Sheng
- Department of Microbiology, Molecular Biology, and Biochemistry University of Idaho, Moscow, Idaho 83844-3052
| | - David A. Sarracino
- Harvard Partners Center For Genetics and Genomics 65 Landsdowne Street Cambridge, Massachusetts 02139
| | - Carolyn J. Hovde
- Department of Microbiology, Molecular Biology, and Biochemistry University of Idaho, Moscow, Idaho 83844-3052
| | - Stephen B. Calderwood
- Division of Infectious Diseases Massachusetts General Hospital Boston, Massachusetts 02114
- Department of Medicine Harvard Medical School Boston, Massachusetts 02114
- Department of Microbiology and Immunobiology Harvard Medical School Boston, Massachusetts 02114
| | - Manohar John
- Division of Infectious Diseases Massachusetts General Hospital Boston, Massachusetts 02114
- Department of Medicine Harvard Medical School Boston, Massachusetts 02114
- Department of Microbiology and Immunobiology Harvard Medical School Boston, Massachusetts 02114
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20
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Cote R, Katani R, Moreau MR, Kudva IT, Arthur TM, DebRoy C, Mwangi MM, Albert I, Raygoza Garay JA, Li L, Brandl MT, Carter MQ, Kapur V. Comparative analysis of super-shedder strains of Escherichia coli O157:H7 reveals distinctive genomic features and a strongly aggregative adherent phenotype on bovine rectoanal junction squamous epithelial cells. PLoS One 2015; 10:e0116743. [PMID: 25664460 PMCID: PMC4321836 DOI: 10.1371/journal.pone.0116743] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Accepted: 12/12/2014] [Indexed: 12/13/2022] Open
Abstract
Shiga toxin-producing Escherichia coli O157:H7 (O157) are significant foodborne pathogens and pose a serious threat to public health worldwide. The major reservoirs of O157 are asymptomatic cattle which harbor the organism in the terminal recto-anal junction (RAJ). Some colonized animals, referred to as “super-shedders” (SS), are known to shed O157 in exceptionally large numbers (>104 CFU/g of feces). Recent studies suggest that SS cattle play a major role in the prevalence and transmission of O157, but little is known about the molecular mechanisms associated with super-shedding. Whole genome sequence analysis of an SS O157 strain (SS17) revealed a genome of 5,523,849 bp chromosome with 5,430 open reading frames and two plasmids, pO157 and pSS17, of 94,645 bp and 37,446 bp, respectively. Comparative analyses showed that SS17 is clustered with spinach-associated O157 outbreak strains, and belongs to the lineage I/II, clade 8, D group, and genotype 1, a subgroup of O157 with predicted hyper-virulence. A large number of non-synonymous SNPs and other polymorphisms were identified in SS17 as compared with other O157 strains (EC4115, EDL933, Sakai, TW14359), including in key adherence- and virulence-related loci. Phenotypic analyses revealed a distinctive and strongly adherent aggregative phenotype of SS17 on bovine RAJ stratified squamous epithelial (RSE) cells that was conserved amongst other SS isolates. Molecular genetic and functional analyses of defined mutants of SS17 suggested that the strongly adherent aggregative phenotype amongst SS isolates is LEE-independent, and likely results from a novel mechanism. Taken together, our study provides a rational framework for investigating the molecular mechanisms associated with SS, and strong evidence that SS O157 isolates have distinctive features and use a LEE-independent mechanism for hyper-adherence to bovine rectal epithelial cells.
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Affiliation(s)
- Rebecca Cote
- Department of Veterinary and Biomedical Science, The Pennsylvania State University, University Park, Pennsylvania, United States of America
- The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Robab Katani
- Department of Veterinary and Biomedical Science, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Matthew R. Moreau
- Department of Veterinary and Biomedical Science, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Indira T. Kudva
- Food Safety and Enteric Pathogens Research Unit, National Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Ames, Iowa, United States of America
| | - Terrance M. Arthur
- Roman L. Hruska U.S. Meat Animal Research Center, Agricultural Research Service, U.S. Department of Agriculture, Clay Center, Nebraska, United States of America
| | - Chitrita DebRoy
- Department of Veterinary and Biomedical Science, The Pennsylvania State University, University Park, Pennsylvania, United States of America
- E. coli Reference Center, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Michael M. Mwangi
- The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania, United States of America
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Istvan Albert
- The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania, United States of America
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Juan Antonio Raygoza Garay
- Department of Veterinary and Biomedical Science, The Pennsylvania State University, University Park, Pennsylvania, United States of America
- The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Lingling Li
- Department of Veterinary and Biomedical Science, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Maria T. Brandl
- Produce Safety and Microbiology, Research Unit, Agriculture Research Service, U.S. Department of Agriculture, Albany, California, United States of America
| | - Michelle Q. Carter
- Produce Safety and Microbiology, Research Unit, Agriculture Research Service, U.S. Department of Agriculture, Albany, California, United States of America
| | - Vivek Kapur
- Department of Veterinary and Biomedical Science, The Pennsylvania State University, University Park, Pennsylvania, United States of America
- The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania, United States of America
- * E-mail:
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21
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Landstorfer R, Simon S, Schober S, Keim D, Scherer S, Neuhaus K. Comparison of strand-specific transcriptomes of enterohemorrhagic Escherichia coli O157:H7 EDL933 (EHEC) under eleven different environmental conditions including radish sprouts and cattle feces. BMC Genomics 2014; 15:353. [PMID: 24885796 PMCID: PMC4048457 DOI: 10.1186/1471-2164-15-353] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Accepted: 03/31/2014] [Indexed: 12/26/2022] Open
Abstract
Background Multiple infection sources for enterohemorrhagic Escherichia coli O157:H7 (EHEC) are known, including animal products, fruit and vegetables. The ecology of this pathogen outside its human host is largely unknown and one third of its annotated genes are still hypothetical. To identify genetic determinants expressed under a variety of environmental factors, we applied strand-specific RNA-sequencing, comparing the SOLiD and Illumina systems. Results Transcriptomes of EHEC were sequenced under 11 different biotic and abiotic conditions: LB medium at pH4, pH7, pH9, or at 15°C; LB with nitrite or trimethoprim-sulfamethoxazole; LB-agar surface, M9 minimal medium, spinach leaf juice, surface of living radish sprouts, and cattle feces. Of 5379 annotated genes in strain EDL933 (genome and plasmid), a surprising minority of only 144 had null sequencing reads under all conditions. We therefore developed a statistical method to distinguish weakly transcribed genes from background transcription. We find that 96% of all genes and 91.5% of the hypothetical genes exhibit a significant transcriptional signal under at least one condition. Comparing SOLiD and Illumina systems, we find a high correlation between both approaches for fold-changes of the induced or repressed genes. The pathogenicity island LEE showed highest transcriptional activity in LB medium, minimal medium, and after treatment with antibiotics. Unique sets of genes, including many hypothetical genes, are highly up-regulated on radish sprouts, cattle feces, or in the presence of antibiotics. Furthermore, we observed induction of the shiga-toxin carrying phages by antibiotics and confirmed active biofilm related genes on radish sprouts, in cattle feces, and on agar plates. Conclusions Since only a minority of genes (2.7%) were not active under any condition tested (null reads), we suggest that the assumption of significant genome over-annotations is wrong. Environmental transcriptomics uncovered hitherto unknown gene functions and unique regulatory patterns in EHEC. For instance, the environmental function of azoR had been elusive, but this gene is highly active on radish sprouts. Thus, NGS-transcriptomics is an appropriate technique to propose new roles of hypothetical genes and to guide future research. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-353) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | | | | | | | | | - Klaus Neuhaus
- Lehrstuhl für Mikrobielle Ökologie, Wissenschaftszentrum Weihenstephan, Technische Universität München, Weihenstephaner Berg 3, D-85350 Freising, Germany.
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Stanford K, Hannon S, Booker CW, Jim GK. Variable efficacy of a vaccine and direct-fed microbial for controlling Escherichia coli O157:H7 in feces and on hides of feedlot cattle. Foodborne Pathog Dis 2014; 11:379-87. [PMID: 24673729 DOI: 10.1089/fpd.2013.1693] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
To evaluate the efficacy of a type-III secreted proteins vaccine and a Lactobacillus-acidophilus-based direct-fed microbial (DFM) for controlling Escherichia coli O157:H7, cattle (n=864) were allocated to the following groups: DFM, finishing diets containing 10(9) colony-forming units (CFU)/animal/day L. acidophilus and Propionibacterium freudenreichii; VAC, finishing diets and 2 mL intramuscular injection of vaccine at allocation and 28 days later; or CON, finishing diets only. Cattle within replicates were stratified by initial levels of E. coli O157:H7 and randomized to experimental groups, with 30 pens allocated on June 15, 2011 (AS1), 18 pens allocated on June 28, 2011 (AS2), and 18 cattle per pen. Rectal fecal samples and perineal swabs were collected at 28-day intervals until shipment to slaughter (103-145 days on trial). Numbers of cattle with enumerable E. coli O157:H7 (≥1.6 CFU/g feces) were reduced in AS1 and AS2 by VAC (p=0.008), although interventions had no impact on numbers of E. coli O157:H7 shed. For AS1, VAC reduced prevalence of E. coli O157:H7 in feces (p=0.03) and perineal swabs (p=0.04) in the feeding period but not at shipment to slaughter. For AS2, prevalence of E. coli O157:H7 was not reduced in either feces or perineal swabs by VAC at any time. For AS1, DFM reduced prevalence of E. coli O157:H7 in perineal swabs (p=0.01) during the feeding period. For AS2, DFM increased E. coli O157:H7 detection in feces (p=0.03) and perineal swabs (p=0.01) at shipment to slaughter. Seventy-five percent of AS1 E. coli O157:H7 isolates had only stx1, while 87% of AS2 isolates had stx1 and stx2 genes. Of the two interventions, VAC shows the most potential for pre-harvest control of E. coli O157:H7, but due to variable efficacy of both DFM and VAC, additional product development is necessary to ensure more consistent pre-harvest control of E. coli O157:H7.
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Affiliation(s)
- Kim Stanford
- 1 Alberta Agriculture and Rural Development, Agriculture Centre , Lethbridge, Alberta, Canada
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Kudva IT, Stasko JA. Bison and bovine rectoanal junctions exhibit similar cellular architecture and Escherichia coli O157 adherence patterns. BMC Vet Res 2013; 9:266. [PMID: 24373611 PMCID: PMC3878412 DOI: 10.1186/1746-6148-9-266] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Accepted: 12/18/2013] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Escherichia coli O157 (E. coli O157) has been isolated from bison retail meat, a fact that is important given that bison meat has been implicated in an E. coli O157-multistate outbreak. In addition, E. coli O157 has also been isolated from bison feces at slaughter and on farms. Cattle are well documented as E. coli O157 reservoirs, and the primary site of E. coli O157 persistence in such reservoirs is the rectoanal junction (RAJ), located at the distal end of the bovine gastrointestinal tract. Since bison and cattle share many genetic similarities manifested as common lineage, susceptibility to infection and the nature of immune responses to infectious agents, we decided to evaluate whether the RAJ of these animals were comparable both in terms of cellular architecture and as sites for adherence of E. coli O157. Specifically, we compared the histo-morphologies of the RAJ and evaluated the E. coli O157 adherence characteristics to the RAJ squamous epithelial (RSE) cells, from these two species. RESULTS We found that the RAJ of both bison and cattle demonstrated similar distribution of epithelial cell markers villin, vimentin, cytokeratin, E-cadherin and N-cadherin. Interestingly, N-cadherin predominated in the stratified squamous epithelium reflecting its proliferative nature. E. coli O157 strains 86-24 SmR and EDL 933 adhered to RSE cells from both animals with similar diffuse and aggregative patterns, respectively. CONCLUSION Our observations further support the fact that bison are likely 'wildlife' reservoirs for E. coli O157, harboring these bacteria in their gastrointestinal tract. Our results also extend the utility of the RSE-cell assay, previously developed to elucidate E. coli O157-cattle RAJ interactions, to studies in bison, which are warranted to determine whether these observations in vitro correlate with those occurring in vivo at the RAJ within the bison gastrointestinal tract.
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Affiliation(s)
- Indira T Kudva
- Food Safety and Enteric Pathogens Research Unit, National Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Ames, IA 50010, USA
| | - Judith A Stasko
- Microscopy Services Laboratory, National Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Ames, IA 50010, USA
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Zhao H, Chen C, Xiong Y, Xu X, Lan R, Wang H, Yao X, Bai X, Liu X, Meng Q, Zhang X, Sun H, Zhao A, Bai X, Cheng Y, Chen Q, Ye C, Xu J. Global transcriptional and phenotypic analyses of Escherichia coli O157:H7 strain Xuzhou21 and its pO157_Sal cured mutant. PLoS One 2013; 8:e65466. [PMID: 23738017 PMCID: PMC3667801 DOI: 10.1371/journal.pone.0065466] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Accepted: 04/26/2013] [Indexed: 12/05/2022] Open
Abstract
Escherichia coli O157:H7 is an important food-borne pathogen that can cause hemorrhagic colitis and hemolytic-uremic syndrome in humans. pO157_Sal, a novel conjugative plasmid is present in a Chinese O157:H7 outbreak strain Xuzhou21. Here we investigated the phenotypic and transcriptional differences between the wild type strain Xuzhou21 and the pO157_Sal cured mutant strain Xuzhou21m. RNA-Seq analysis found that all 52 ORFs encoded on pO157_Sal were transcribed. One hundred and sixty eight chromosomal and pO157 genes were differentially expressed (≥2 fold difference) between Xuzhou21 and Xuzhou21m. Sixty-seven and 101 genes were up-regulated and down-regulated respectively by pO157_Sal including genes related to stress response, adaption and virulence. The plasmid-cured mutant Xuzhou21m grew slower than wild type Xuzhou21 and pO157_Sal plasmid complemented strain Xuzhou21c in M9 medium under the condition of high NaCl or presence of sodium deoxycholate (NaDC), corroborating with the RNA-Seq data. Seven differentially expressed genes are associated with NaDC resistance, including the adenine-specific DNA-methyltransferase gene (dam), multidrug efflux system subunit gene mdtA, hyperosmotically inducible periplasmic protein gene osmY and oxidation-reduction related genes while two differentially expressed genes (osmY and pspD) are likely to be related to resistance to osmotic pressure. A number of differentially expressed genes were virulence associated including four genes encoding T3SS effectors from the chromosome and ehxD from pO157. Through complementation of Xuzhou21m with a plasmid construct carrying the pO157_Sal hha homolog we further showed that the pO157_Sal hha represses the expression of T3SS effectors. These findings demonstrated that the plasmid pO157_Sal affects the transcription of the chromosomal and pO157 plasmid genes and contributes to the enhanced ability to resist stress. We conclude that pO157_Sal plays an important role in regulating global gene expression and affects the virulence and adaptation of E. coli O157:H7.
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Affiliation(s)
- Hongqing Zhao
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, Changping, Beijing, China
| | - Chen Chen
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, Changping, Beijing, China
| | - Yanwen Xiong
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, Changping, Beijing, China
| | - Xuefang Xu
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, Changping, Beijing, China
| | - Ruiting Lan
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Haiyin Wang
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, Changping, Beijing, China
| | - Xinyue Yao
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, Changping, Beijing, China
| | - Xiangning Bai
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, Changping, Beijing, China
| | - Xuetong Liu
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, Changping, Beijing, China
| | - Qiong Meng
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, Changping, Beijing, China
| | - Xiaoai Zhang
- Beijing Center for Disease Prevention and Control, Beijing, China
| | - Hui Sun
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, Changping, Beijing, China
| | - Ailan Zhao
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, Changping, Beijing, China
| | - Xuemei Bai
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, Changping, Beijing, China
| | - Yuli Cheng
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, Changping, Beijing, China
| | - Qiang Chen
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, Changping, Beijing, China
| | - Changyun Ye
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, Changping, Beijing, China
| | - Jianguo Xu
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, Changping, Beijing, China
- * E-mail:
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Growth media simulating ileal and colonic environments affect the intracellular proteome and carbon fluxes of enterohemorrhagic Escherichia coli O157:H7 strain EDL933. Appl Environ Microbiol 2013; 79:3703-15. [PMID: 23563955 DOI: 10.1128/aem.00062-13] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In this study, the intracellular proteome of Escherichia coli O157:H7 strain EDL933 was analyzed by two-dimensional gel electrophoresis and matrix-assisted laser desorption ionization-time-of-flight (MALDI-TOF) spectrometry after growth in simulated ileal environment media (SIEM) and simulated colonic environment media (SCEM) under aerobic and microaerobic conditions. Differentially expressed intracellular proteins were identified and allocated to functional protein groups. Moreover, metabolic fluxes were analyzed by isotopologue profiling with [U-(13)C(6)]glucose as a tracer. The results of this study show that EDL933 responds with differential expression of a complex network of proteins and metabolic pathways, reflecting the high metabolic adaptability of the strain. Growth in SIEM and SCEM is obviously facilitated by the upregulation of nucleotide biosynthesis pathway proteins and could be impaired by exposition to 50 µM 6-mercaptopurine under aerobic conditions. Notably, various stress and virulence factors, including Shiga toxin, were expressed without having contact with a human host.
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Kudva IT, Hovde CJ, John M. Adherence of non-O157 Shiga toxin-producing Escherichia coli to bovine recto-anal junction squamous epithelial cells appears to be mediated by mechanisms distinct from those used by O157. Foodborne Pathog Dis 2013; 10:375-81. [PMID: 23510495 PMCID: PMC3661034 DOI: 10.1089/fpd.2012.1382] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
This study presents evidence that the pattern (diffuse or aggregative) of adherence of clinically relevant non-O157 Shiga toxin-producing Escherichia coli (STEC) to bovine recto-anal junction squamous epithelial cells is similar to that of E. coli O157, although the mechanisms of adherence appear to be distinct. Our results further suggest that novel adhesins, and not Intimin, are likely involved in non-O157 STEC adherence to bovine recto-anal junction squamous epithelial cells. These findings have important implications for the development of efficacious modalities for blocking adherence of non-O157 STEC to bovine gastrointestinal epithelial cells.
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Affiliation(s)
- Indira T Kudva
- Food Safety and Enteric Pathogens Research Unit, National Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Ames, Iowa 50010, USA.
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