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Ye D, Nguyen PT, Bourgault S, Couture M. The heme binding protein ChuX is a regulator of heme degradation by the ChuS protein in Escherichia coli O157:H7. J Inorg Biochem 2024; 256:112575. [PMID: 38678912 DOI: 10.1016/j.jinorgbio.2024.112575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Revised: 04/17/2024] [Accepted: 04/23/2024] [Indexed: 05/01/2024]
Abstract
Escherichia coli O157:H7 possesses an 8-gene cluster (chu genes) that contains genes involved in heme transport and processing from the human host. Among the chu genes, four encode cytoplasmic proteins (ChuS, ChuX, ChuY and ChuW). ChuX was previously shown to be a heme binding protein and to assist ChuW in heme degradation under anaerobic conditions. The purpose of this work was to investigate if ChuX works in concert with ChuS, which is a protein able to degrade heme by a non-canonical mechanism and release the iron from the porphyrin under aerobic conditions using hydrogen peroxide as the oxidant. We showed that when the heme-bound ChuX and apo-ChuS protein are mixed, heme is efficiently transferred from ChuX to ChuS. Heme-bound ChuX displayed a peroxidase activity with ABTS and H2O2 but not heme-bound ChuS, which is an efficient test to determine the protein to which heme is bound in the ChuS-ChuX complex. We found that ChuX protects heme from chemical oxidation and that it has no heme degradation activity by itself. Unexpectedly, we found that ChuX inhibits heme degradation by ChuS and stops the reaction at an early intermediate. We determined using surface plasmon resonance that ChuX interacts with ChuS and that it forms a relatively stable complex. These results indicate that ChuX in addition to its heme transfer activity is a regulator of ChuS activity, a function that was not described before for any of the heme carrier protein that delivers heme to heme degradation enzymes.
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Affiliation(s)
- Danrong Ye
- Department of Biochemistry, Microbiology and Bioinformatics, Université Laval, Quebec City, QC, Canada; Institut de Biologie Intégrative et des Systèmes (IBIS) and PROTEO, Université Laval, Quebec city, QC, Canada; Quebec Network for Research on Protein Function, Engineering and Applications (PROTEO), Montreal, QC, Canada
| | - Phuong Trang Nguyen
- Quebec Network for Research on Protein Function, Engineering and Applications (PROTEO), Montreal, QC, Canada; Departement of Chemistry, Université du Québec à Montréal, Montreal, QC, Canada
| | - Steve Bourgault
- Quebec Network for Research on Protein Function, Engineering and Applications (PROTEO), Montreal, QC, Canada; Departement of Chemistry, Université du Québec à Montréal, Montreal, QC, Canada
| | - Manon Couture
- Department of Biochemistry, Microbiology and Bioinformatics, Université Laval, Quebec City, QC, Canada; Institut de Biologie Intégrative et des Systèmes (IBIS) and PROTEO, Université Laval, Quebec city, QC, Canada; Quebec Network for Research on Protein Function, Engineering and Applications (PROTEO), Montreal, QC, Canada.
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2
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Wang Q, Wei Y, Huang Y, Qin J, Liu B, Liu R, Chen X, Li D, Wang Q, Li X, Yang X, Li Y, Sun H. Z3495, a LysR-Type Transcriptional Regulator Encoded in O Island 97, Regulates Virulence Gene Expression in Enterohemorrhagic Escherichia coli O157:H7. Microorganisms 2024; 12:140. [PMID: 38257967 PMCID: PMC10819331 DOI: 10.3390/microorganisms12010140] [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: 12/13/2023] [Revised: 01/07/2024] [Accepted: 01/08/2024] [Indexed: 01/24/2024] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) is an important foodborne pathogen that infects humans by colonizing the large intestine. The genome of EHEC O157:H7 contains 177 unique O islands (OIs). Certain OIs significantly contribute to the heightened virulence and pathogenicity exhibited by EHEC O157:H7. However, the function of most OI genes remains unknown. We demonstrated here that EHEC O157:H7 adherence to and colonization of the mouse large intestine are both dependent on OI-97. Z3495, which is annotated as a LysR-type transcriptional regulator and encoded in OI-97, contributes to this phenotype. Z3495 activated the locus of enterocyte effacement (LEE) gene expression, promoting bacterial adherence. Deletion of z3495 significantly decreased the transcription of ler and other LEE genes, the ability to adhere to the host cells, and colonization in the mouse large intestine. Furthermore, the ChIP-seq results confirmed that Z3495 can directly bind to the promoter region of rcsF, which is a well-known activator of Ler, and increase LEE gene expression. Finally, phylogenetic analysis revealed that Z3495 is a widespread transcriptional regulator in enterohemorrhagic and enteropathogenic Escherichia coli. As a result of this study, we have gained a deeper understanding of how bacteria control their virulence and provide another example of a laterally acquired regulator that regulates LEE gene expression in bacteria.
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Affiliation(s)
- Qian Wang
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300457, China; (Q.W.); (Y.H.); (X.L.)
- Tianjin Key Laboratory of Microbial Functional Genomics, TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin 300457, China
| | - Yi Wei
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300457, China; (Q.W.); (Y.H.); (X.L.)
- Tianjin Key Laboratory of Microbial Functional Genomics, TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin 300457, China
| | - Yu Huang
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300457, China; (Q.W.); (Y.H.); (X.L.)
- Tianjin Key Laboratory of Microbial Functional Genomics, TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin 300457, China
| | - Jingliang Qin
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300457, China; (Q.W.); (Y.H.); (X.L.)
- Tianjin Key Laboratory of Microbial Functional Genomics, TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin 300457, China
| | - Bin Liu
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300457, China; (Q.W.); (Y.H.); (X.L.)
- Tianjin Key Laboratory of Microbial Functional Genomics, TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin 300457, China
- Nankai International Advanced Research Institute, Shenzhen 518045, China
| | - Ruiying Liu
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300457, China; (Q.W.); (Y.H.); (X.L.)
- Tianjin Key Laboratory of Microbial Functional Genomics, TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin 300457, China
| | - Xintong Chen
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300457, China; (Q.W.); (Y.H.); (X.L.)
- Tianjin Key Laboratory of Microbial Functional Genomics, TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin 300457, China
| | - Dan Li
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300457, China; (Q.W.); (Y.H.); (X.L.)
- Tianjin Key Laboratory of Microbial Functional Genomics, TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin 300457, China
| | - Qiushi Wang
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300457, China; (Q.W.); (Y.H.); (X.L.)
- Tianjin Key Laboratory of Microbial Functional Genomics, TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin 300457, China
| | - Xiaoya Li
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300457, China; (Q.W.); (Y.H.); (X.L.)
- Tianjin Key Laboratory of Microbial Functional Genomics, TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin 300457, China
| | - Xinyuan Yang
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300457, China; (Q.W.); (Y.H.); (X.L.)
- Tianjin Key Laboratory of Microbial Functional Genomics, TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin 300457, China
| | - Yuanke Li
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin 300071, China
| | - Hao Sun
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300457, China; (Q.W.); (Y.H.); (X.L.)
- Tianjin Key Laboratory of Microbial Functional Genomics, TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin 300457, China
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3
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Wang Z, Cui X, Hu A, Lu Z, Meng F, Zhou L, Bie X. Establishment of real-time fluorescence and visual LAMP for rapid detection of Escherichia coli O157:H7 and kits construction. Lett Appl Microbiol 2023; 76:ovad122. [PMID: 37863833 DOI: 10.1093/lambio/ovad122] [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: 08/03/2023] [Revised: 09/23/2023] [Accepted: 10/19/2023] [Indexed: 10/22/2023]
Abstract
Escherichia coli O157:H7 is a common pathogenic bacterium in food and water that can pose a threat to human health. The aim of this study was to develop loop-mediated isothermal amplification (LAMP) method for the detection of E. coli O157:H7 in food based on the specific gene Ecs_2840 and to construct rapid detection kits based on the established methods. Specifically, we established two methods of real-time fluorescent LAMP (RT-LAMP) and visual LAMP with calcein as an indicator. In pure bacterial culture, the cell sensitivity and genomic sensitivity of the RT-LAMP kit were 8.8 × 100 CFU ml-1 and 4.61 fg µl-1, respectively. The sensitivity of the visual LAMP kit was 2.35 × 100 CFU ml-1 and 4.61 fg µl-1. Both kits had excellent specificity and anti-interference performance. In addition, milk inoculated with 2.26 × 100 CFU ml-1E. coli O157:H7 could be detected within the reaction time after enrichment for 3 h. The results showed that the LAMP kits were rapid, sensitive, and specific for the detection of E. coli O157:H7 in food and had good application prospects in food safety surveillance.
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Affiliation(s)
- Zuwei Wang
- Nanjing Agricultural University, College of Food Science and Technology, Nanjing 210095, People's Republic of China
| | - Xinping Cui
- Nanjing Agricultural University, College of Food Science and Technology, Nanjing 210095, People's Republic of China
| | - Antuo Hu
- Nanjing Agricultural University, College of Food Science and Technology, Nanjing 210095, People's Republic of China
| | - Zhaoxin Lu
- Nanjing Agricultural University, College of Food Science and Technology, Nanjing 210095, People's Republic of China
| | - Fanqiang Meng
- Nanjing Agricultural University, College of Food Science and Technology, Nanjing 210095, People's Republic of China
| | - Libang Zhou
- Nanjing Agricultural University, College of Food Science and Technology, Nanjing 210095, People's Republic of China
| | - Xiaomei Bie
- Nanjing Agricultural University, College of Food Science and Technology, Nanjing 210095, People's Republic of China
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4
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Yang W, Sun H, Yan J, Kang C, Wu J, Yang B. Enterohemorrhagic Escherichia coli senses microbiota-derived nicotinamide to increase its virulence and colonization in the large intestine. Cell Rep 2023; 42:112638. [PMID: 37294635 DOI: 10.1016/j.celrep.2023.112638] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 05/05/2023] [Accepted: 05/25/2023] [Indexed: 06/11/2023] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is a foodborne pathogen that specifically colonizes and infects the human large intestine. EHEC O157:H7 engages intricate regulatory pathways to detect host intestinal signals and regulate virulence-related gene expression during colonization and infection. However, the overall EHEC O157:H7 virulence regulatory network in the human large intestine remains incompletely understood. Here, we report a complete signal regulatory pathway where the EvgSA two-component system responds to high-nicotinamide levels produced by microbiota in the large intestine and directly activates loci of enterocyte effacement genes to promote EHEC O157:H7 adherence and colonization. This EvgSA-mediated nicotinamide signaling regulatory pathway is conserved and widespread among several other EHEC serotypes. Moreover, disruption of this virulence-regulating pathway by the deletion of evgS or evgA significantly decreased EHEC O157:H7 adherence and colonization in the mouse intestinal tract, indicating that these genes could be potential targets for the development of new therapeutics for EHEC O157:H7 infection.
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Affiliation(s)
- Wen Yang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin 300457, P.R. China; The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin 300071, P.R. China
| | - Hongmin Sun
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin 300457, P.R. China; The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin 300071, P.R. China
| | - Jun Yan
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin 300457, P.R. China; The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin 300071, P.R. China
| | - Chenbo Kang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin 300457, P.R. China; The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin 300071, P.R. China
| | - Junli Wu
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin 300457, P.R. China; The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin 300071, P.R. China
| | - Bin Yang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin 300457, P.R. China; The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin 300071, P.R. China.
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5
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Sultan-Alolama MI, Amin A, Vijayan R, El-Tarabily KA. Isolation, Characterization, and Comparative Genomic Analysis of Bacteriophage Ec_MI-02 from Pigeon Feces Infecting Escherichia coli O157:H7. Int J Mol Sci 2023; 24:ijms24119506. [PMID: 37298457 DOI: 10.3390/ijms24119506] [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: 04/19/2023] [Revised: 05/23/2023] [Accepted: 05/26/2023] [Indexed: 06/12/2023] Open
Abstract
The most significant serotype of Shiga-toxigenic Escherichia coli that causes foodborne illnesses is Escherichia coli O157:H7. Elimination of E. coli O157:H7 during food processing and storage is a possible solution. Bacteriophages have a significant impact on bacterial populations in nature due to their ability to lyse their bacterial host. In the current study, a virulent bacteriophage, Ec_MI-02, was isolated from the feces of a wild pigeon in the United Arab Emirates (UAE) for potential future use as a bio-preservative or in phage therapy. Using a spot test and an efficiency of plating analysis, Ec_MI-02 was found to infect in addition to the propagation host, E. coli O157:H7 NCTC 12900, five different serotypes of E. coli O157:H7 (three clinical samples from infected patients, one from contaminated green salad, and one from contaminated ground beef). Based on morphology and genome analysis, Ec_MI-02 belongs to the genus Tequatrovirus under the order Caudovirales. The adsorption rate constant (K) of Ec_MI-02 was found to be 1.55 × 10-8 mL/min. The latent period was 50 min with a burst size of almost 10 plaque forming units (pfu)/host cell in the one-step growth curve when the phage Ec_MI-02 was cultivated using the propagation host E. coli O157:H7 NCTC 12900. Ec_MI-02 was found to be stable at a wide range of pH, temperature, and commonly used laboratory disinfectants. Its genome is 165,454 bp long with a GC content of 35.5% and encodes 266 protein coding genes. Ec_MI-02 has genes encoding for rI, rII, and rIII lysis inhibition proteins, which supports the observation of delayed lysis in the one-step growth curve. The current study provides additional evidence that wild birds could also be a good natural reservoir for bacteriophages that do not carry antibiotic resistance genes and could be good candidates for phage therapy. In addition, studying the genetic makeup of bacteriophages that infect human pathogens is crucial for ensuring their safe usage in the food industry.
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Affiliation(s)
- Mohamad Ismail Sultan-Alolama
- Zayed Complex for Herbal Research and Traditional Medicine, Research and Innovation Center, Department of Health, Abu Dhabi 5674, United Arab Emirates
- Department of Biology, College of Science, United Arab Emirates University, Al Ain P.O. Box 15551, United Arab Emirates
| | - Amr Amin
- Department of Biology, College of Science, United Arab Emirates University, Al Ain P.O. Box 15551, United Arab Emirates
| | - Ranjit Vijayan
- Department of Biology, College of Science, United Arab Emirates University, Al Ain P.O. Box 15551, United Arab Emirates
- The Big Data Analytics Center, United Arab Emirates University, Al Ain P.O. Box 15551, United Arab Emirates
- Zayed Center for Health Sciences, United Arab Emirates University, Al Ain P.O. Box 17666, United Arab Emirates
| | - Khaled A El-Tarabily
- Department of Biology, College of Science, United Arab Emirates University, Al Ain P.O. Box 15551, United Arab Emirates
- Khalifa Center for Genetic Engineering and Biotechnology, United Arab Emirates University, Al Ain P.O. Box 15551, United Arab Emirates
- Harry Butler Institute, Murdoch University, Murdoch, WA 6150, Australia
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6
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Gemler BT, Mukherjee C, Howland CA, Huk D, Shank Z, Harbo LJ, Tabbaa OP, Bartling CM. Function-based classification of hazardous biological sequences: Demonstration of a new paradigm for biohazard assessments. Front Bioeng Biotechnol 2022; 10:979497. [PMID: 36277394 PMCID: PMC9585941 DOI: 10.3389/fbioe.2022.979497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 08/31/2022] [Indexed: 12/04/2022] Open
Abstract
Bioengineering applies analytical and engineering principles to identify functional biological building blocks for biotechnology applications. While these building blocks are leveraged to improve the human condition, the lack of simplistic, machine-readable definition of biohazards at the function level is creating a gap for biosafety practices. More specifically, traditional safety practices focus on the biohazards of known pathogens at the organism-level and may not accurately consider novel biodesigns with engineered functionalities at the genetic component-level. This gap is motivating the need for a paradigm shift from organism-centric procedures to function-centric biohazard identification and classification practices. To address this challenge, we present a novel methodology for classifying biohazards at the individual sequence level, which we then compiled to distinguish the biohazardous property of pathogenicity at the whole genome level. Our methodology is rooted in compilation of hazardous functions, defined as a set of sequences and associated metadata that describe coarse-level functions associated with pathogens (e.g., adherence, immune subversion). We demonstrate that the resulting database can be used to develop hazardous “fingerprints” based on the functional metadata categories. We verified that these hazardous functions are found at higher levels in pathogens compared to non-pathogens, and hierarchical clustering of the fingerprints can distinguish between these two groups. The methodology presented here defines the hazardous functions associated with bioengineering functional building blocks at the sequence level, which provide a foundational framework for classifying biological hazards at the organism level, thus leading to the improvement and standardization of current biosecurity and biosafety practices.
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Sun H, Wang M, Liu Y, Wu P, Yao T, Yang W, Yang Q, Yan J, Yang B. Regulation of flagellar motility and biosynthesis in enterohemorrhagic Escherichia coli O157:H7. Gut Microbes 2022; 14:2110822. [PMID: 35971812 PMCID: PMC9387321 DOI: 10.1080/19490976.2022.2110822] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
ABSTARCTEnterohemorrhagic Escherichia coli (EHEC) O157:H7 is a human pathogen that causes a variety of diseases, such as hemorrhagic colitis and lethal hemolytic uremic syndrome. Flagellum-dependent motility plays diverse roles in the pathogenesis of EHEC O157:H7, including its migration to an optimal host site, adherence and colonization, survival at the infection site, and post-infection dispersal. However, it is very expensive for cellular economy in terms of the number of genes and the energy required for flagellar biosynthesis and functioning. Furthermore, the flagellar filament bears strong antigenic properties that induce a strong host immune response. Consequently, the flagellar gene expression and biosynthesis are highly regulated to occur at the appropriate time and place by different regulatory influences. The present review focuses on the regulatory mechanisms of EHEC O157:H7 motility and flagellar biosynthesis, especially in terms of flagellar gene regulation by environmental factors, regulatory proteins, and small regulatory RNAs.
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Affiliation(s)
- Hongmin Sun
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, China
| | - Min Wang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, China
| | - Yutao Liu
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, China
| | - Pan Wu
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, China
| | - Ting Yao
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, China
| | - Wen Yang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, China
| | - Qian Yang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, China
| | - Jun Yan
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, China
| | - Bin Yang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, China,CONTACT Bin Yang TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin300457, P. R. China
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8
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Elucidation of a complete mechanical signaling and virulence activation pathway in enterohemorrhagic Escherichia coli. Cell Rep 2022; 39:110614. [PMID: 35385749 DOI: 10.1016/j.celrep.2022.110614] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 12/09/2021] [Accepted: 03/13/2022] [Indexed: 12/23/2022] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is an important extracellular human pathogen. The initial adherence of EHEC to host cells is a major cue for transcriptional induction of the locus of enterocyte effacement (LEE) genes to promote colonization and pathogenesis, but the mechanism through which this adherence is sensed and the LEE is induced remains largely elusive. Here, we report a complete signal transduction pathway for this virulence activation process. In this pathway, the outer-membrane lipoprotein NlpE senses a mechanical cue generated from initial host adherence and activates the BaeSR two-component regulatory system; the response regulator BaeR then directly activates the expression of airA located on O-island-134 and encoding a LEE transcriptional activator. Disruption of this pathway severely attenuates EHEC O157:H7 virulence both in vitro and in vivo. This study provides further insights into the evolution of EHEC pathogenesis and the host-pathogen interaction.
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9
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Jiang L, Yang W, Jiang X, Yao T, Wang L, Yang B. Virulence-related O islands in enterohemorrhagic Escherichia coli O157:H7. Gut Microbes 2022; 13:1992237. [PMID: 34711138 PMCID: PMC8565820 DOI: 10.1080/19490976.2021.1992237] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is a principally foodborne pathogen linked to serious diseases, including bloody diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome. Comparative genomics analysis revealed that EHEC O157 contains 177 unique genomic islands, termed O islands, compared with the nonpathogenic E. coli K-12 laboratory strain. These O islands contribute largely to the pathogenicity of EHEC O157:H7 by providing numerous virulence factors, effectors, virulence regulatory proteins, and virulence regulatory sRNAs. The present review aimed to provide a comprehensive understanding of the research progress on the function of O islands, especially focusing on virulence-related O islands.
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Affiliation(s)
- Lingyan Jiang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, P. R. China
| | - Wen Yang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, P. R. China
| | - Xinlei Jiang
- School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin, P. R. China
| | - Ting Yao
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, P. R. China
| | - Lu Wang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, P. R. China
| | - Bin Yang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, P. R. China,CONTACT Bin Yang TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin300457, P. R. China
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10
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Shiga Toxin 2a Binds to Complement Components C3b and C5 and Upregulates Their Gene Expression in Human Cell Lines. Toxins (Basel) 2020; 13:toxins13010008. [PMID: 33374102 PMCID: PMC7824702 DOI: 10.3390/toxins13010008] [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: 11/19/2020] [Revised: 12/16/2020] [Accepted: 12/22/2020] [Indexed: 01/06/2023] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) infections can cause EHEC-associated hemolytic uremic syndrome (eHUS) via its main virulent factor, Shiga toxins (Stxs). Complement has been reported to be involved in the progression of eHUS. The aim of this study was to investigate the interactions of the most effective subtype of the toxin, Stx2a, with pivotal complement proteins C3b and C5. The study further examined the effect of Stx2a stimulation on the transcription and synthesis of these complement proteins in human target cell lines. Binding of Stx2a to C3b and C5 was evaluated by ELISA. Kidney and gut cell lines (HK-2 and HCT-8) were stimulated with varied concentrations of Stx2a. Subsequent evaluation of complement gene transcription was studied by real-time PCR (qPCR), and ELISAs and Western blots were performed to examine protein synthesis of C3 and C5 in supernatants and lysates of stimulated HK-2 cells. Stx2a showed a specific binding to C3b and C5. Gene transcription of C3 and C5 was upregulated with increasing concentrations of Stx2a in both cell lines, but protein synthesis was not. This study demonstrates the binding of Stx2a to complement proteins C3b and C5, which could potentially be involved in regulating complement during eHUS infection, supporting further investigations into elucidating the role of complement in eHUS pathogenesis.
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11
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Pintara A, Jennison A, Rathnayake IU, Mellor G, Huygens F. Core and Accessory Genome Comparison of Australian and International Strains of O157 Shiga Toxin-Producing Escherichia coli. Front Microbiol 2020; 11:566415. [PMID: 33013798 PMCID: PMC7498637 DOI: 10.3389/fmicb.2020.566415] [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: 05/27/2020] [Accepted: 08/17/2020] [Indexed: 12/20/2022] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) is a foodborne pathogen, and serotype O157:H7 is typically associated with severe disease. Australian STEC epidemiology differs from many other countries, as severe outbreaks and HUS cases appear to be more often associated with non-O157 serogroups. It is not known why Australian strains of O157 STEC might differ in virulence to international strains. Here we investigate the reduced virulence of Australian strains. Multiple genetic analyses were performed, including SNP-typing, to compare the core genomes of the Australian to the international isolates, and accessory genome analysis to determine any significant differences in gene presence/absence that could be associated with their phenotypic differences in virulence. The most distinct difference between the isolates was the absence of the stx2a gene in all Australian isolates, with few other notable differences observed in the core and accessory genomes of the O157 STEC isolates analyzed in this study. The presence of stx1a in most Australian isolates was another notable observation. Acquisition of stx2a seems to coincide with the emergence of highly pathogenic STEC. Due to the lack of other notable genotypic differences observed between Australian and international isolates characterized as highly pathogenic, this may be further evidence that the absence of stx2a in Australian O157 STEC could be a significant characteristic defining its mild virulence. Further work investigating the driving force(s) behind Stx prophage loss and acquisition is needed to determine if this potential exists in Australian O157 isolates.
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Affiliation(s)
- Alexander Pintara
- Centre for Immunology and Infection Control, Queensland University of Technology, Herston, QLD, Australia
- School of Biomedical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, QLD, Australia
| | - Amy Jennison
- Public Health Microbiology, Forensic and Scientific Services, Queensland Health, Brisbane, QLD, Australia
| | - Irani U. Rathnayake
- Public Health Microbiology, Forensic and Scientific Services, Queensland Health, Brisbane, QLD, Australia
| | - Glen Mellor
- CSIRO Animal, Food and Health Sciences, Archerfield, QLD, Australia
| | - Flavia Huygens
- Centre for Immunology and Infection Control, Queensland University of Technology, Herston, QLD, Australia
- School of Biomedical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, QLD, Australia
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12
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Dps Protects Enterohemorrhagic Escherichia coli against Acid-Induced Antimicrobial Peptide Killing. J Bacteriol 2020; 202:JB.00114-20. [PMID: 32229529 DOI: 10.1128/jb.00114-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 03/23/2020] [Indexed: 11/20/2022] Open
Abstract
Dps, a DNA-binding protein from starved cells in Escherichia coli, is part of the bacterial defense system that protects DNA against various cellular stresses. Our lab previously demonstrated that a novel antimicrobial peptide, WRWYCR, enhances acid-induced killing of enterohemorrhagic Escherichia coli (EHEC) and ameliorates infection in a Citrobacter rodentium mouse model of EHEC infection. WRWYCR has previously been shown to compromise DNA damage repair and to increase chelatable iron within the cell. These findings, combined with the effects of peptide and acid stress on DNA damage, suggest a key defense role for Dps in peptide-induced killing of EHEC. The goal of this study is to evaluate the role of Dps in peptide-induced killing of EHEC through survival assays and flow cytometric analyses of DNA damage and hydroxyl radical formation. Our results demonstrate that disruption of the dps gene in stationary-phase EHEC O157:H7 cells, but not in exponential-phase cells, enhances acid-, peptide-, and peptide-acid-induced killing relative to that of wild-type (WT) EHEC. Using flow cytometric analysis, we have also demonstrated increased levels of hydroxyl radicals in peptide-treated wild-type EHEC relative to those in the untreated control. Disruption of the dps gene further increases this. These findings indicate that peptide treatment of EHEC enhances the formation of hydroxyl radicals, likely through the Fenton reaction, thereby contributing to the killing action of the peptide, and that dps protects against peptide killing of EHEC. This study provides important insights into peptide WRWYCR-mediated killing of EHEC, which could be exploited in the development of more effective antimicrobials.IMPORTANCE The research presented in this paper explores the role of the DNA-binding protein Dps as a key defense mechanism of enterohemorrhagic Escherichia coli (EHEC) strains in protecting against killing by the novel antimicrobial peptide WRWYCR. Our results demonstrate that Dps protects against peptide-induced killing of EHEC through direct protection against acid stress and hydroxyl radical formation, both of which are mechanisms targeted by the antimicrobial peptide. This study provides important insights into peptide WRWYCR-mediated killing of EHEC, which could be exploited in the development of more effective antimicrobials through specific targeting of Dps in order to allow a more potent response to the antimicrobial WRWYCR.
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13
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Malavolta M, Basso A, Giacconi R, Orlando F, Pierpaoli E, Cardelli M, Leoni F, Chierichetti S, Bray D, Benlhassan K, Provinciali M. Recovery from mild Escherichia coli O157:H7 infection in young and aged C57BL/6 mice with intact flora estimated by fecal shedding, locomotor activity and grip strength. Comp Immunol Microbiol Infect Dis 2018; 63:1-9. [PMID: 30961802 DOI: 10.1016/j.cimid.2018.12.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 11/30/2018] [Accepted: 12/07/2018] [Indexed: 02/04/2023]
Abstract
Escherichia coli 0157:H7 is a food-borne pathogen that can cause severe complications in vulnerable populations. Mouse infection models of E. coli 0157:H7 are usually developed under severe animal suffering classification by depleting the normal flora, in which age plays a role. OBJECTIVE To develop a refined method for longitudinal monitoring of E. coli 0157:H7 in young and old mice with intact flora. METHODS We applied discriminant analysis and computed composite standardized scores from 19 variables obtained from physiological parameters, analysis of locomotor activity, grip strength measurement and fecal shedding in 16 aged and 16 young C57BL/6 mice after two mild oral challenges of E. coli 0157:H7. The resulting scores were validated in another experiment performed in 24 aged and 24 young mice including a group (8 aged and 8 young mice) treated with oxytetracycline. RESULTS We show that our scores are significantly affected in the post-infection period and that can be used to measure and compare the recovery time after a treatment. The scores are most sensitive when separately developed in young and aged mice. CONCLUSIONS We developed a method that minimizes the level of animal suffering and that can be applied in preclinical testing of new therapies.
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Affiliation(s)
- Marco Malavolta
- Advanced Technology Center for Aging Research, Scientific Technological Area, IRCCS INRCA, Italy.
| | - Andrea Basso
- Advanced Technology Center for Aging Research, Scientific Technological Area, IRCCS INRCA, Italy
| | - Robertina Giacconi
- Advanced Technology Center for Aging Research, Scientific Technological Area, IRCCS INRCA, Italy
| | - Fiorenza Orlando
- Advanced Technology Center for Aging Research, Scientific Technological Area, IRCCS INRCA, Italy
| | - Elisa Pierpaoli
- Advanced Technology Center for Aging Research, Scientific Technological Area, IRCCS INRCA, Italy
| | - Maurizio Cardelli
- Advanced Technology Center for Aging Research, Scientific Technological Area, IRCCS INRCA, Italy
| | - Francesca Leoni
- Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche, Ancona, Italy
| | - Serena Chierichetti
- Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche, Ancona, Italy
| | | | | | - Mauro Provinciali
- Advanced Technology Center for Aging Research, Scientific Technological Area, IRCCS INRCA, Italy
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14
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Postema MM, Grega-Larson NE, Neininger AC, Tyska MJ. IRTKS (BAIAP2L1) Elongates Epithelial Microvilli Using EPS8-Dependent and Independent Mechanisms. Curr Biol 2018; 28:2876-2888.e4. [PMID: 30197089 DOI: 10.1016/j.cub.2018.07.022] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 06/05/2018] [Accepted: 07/09/2018] [Indexed: 11/24/2022]
Abstract
Transporting epithelial cells like those that line the gut build large arrays of actin-supported protrusions called microvilli, which extend from the apical surface into luminal spaces to increase functional surface area. Although critical for maintaining physiological homeostasis, mechanisms controlling the formation of microvilli remain poorly understood. Here, we report that the inverse-bin-amphiphysin-Rvs (I-BAR)-domain-containing protein insulin receptor tyrosine kinase substrate (IRTKS) (also known as BAIAP2L1) promotes the growth of epithelial microvilli. Super-resolution microscopy and live imaging of differentiating epithelial cells revealed that IRTKS localizes to the distal tips of actively growing microvilli via a mechanism that requires its N-terminal I-BAR domain. At microvillar tips, IRTKS promotes elongation through a mechanism involving its C-terminal actin-binding WH2 domain. IRTKS can also drive microvillar elongation using its SH3 domain to recruit the bundling protein EPS8 to microvillar tips. These results provide new insight on mechanisms that control microvillar growth during the differentiation of transporting epithelial cells and help explain why IRTKS is targeted by enteric pathogens that disrupt microvillar structure during infection of the intestinal epithelium.
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Affiliation(s)
- Meagan M Postema
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Nathan E Grega-Larson
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Abigail C Neininger
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Matthew J Tyska
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, USA.
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15
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Yang B, Wang S, Huang J, Yin Z, Jiang L, Hou W, Li X, Feng L. Transcriptional Activator GmrA, Encoded in Genomic Island OI-29, Controls the Motility of Enterohemorrhagic Escherichia coli O157:H7. Front Microbiol 2018. [PMID: 29520261 PMCID: PMC5826968 DOI: 10.3389/fmicb.2018.00338] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Enterohemorrhagic Escherichia coli O157:H7 is a major human enteric pathogen capable of causing large outbreaks of severe infections that induce bloody diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome. Its genome contains 177 unique O islands (OIs) including those carrying the main virulence elements, Shiga toxin-converting phages (OI-45 and OI-93) and locus for enterocyte effacement (OI-148). However, many of these islands harbor only genes of unknown function. Here, we demonstrate that OI-29 encodes a newly discovered transcriptional activator, Z0639 (named GmrA), that is required for motility and flagellar synthesis in O157:H7. GmrA directly binds to the promoter of fliA, an RNA polymerase sigma factor, and thereby regulates flagellar genes controlled by FliA. Expression of gmrA is maximal under host conditions (37°C, neutral pH, and physiological osmolarity), and in the presence of host epithelial cells, indicative of a role of this gene in infection by promoting motility. Finally, GmrA was found to be a widespread regulator of bacterial motility and flagellar synthesis in different pathotypes of E. coli. Our work largely enriches our understanding of bacterial motility control, and provides another example of regulators acquired laterally that mediate flagellar synthesis.
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Affiliation(s)
- Bin Yang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, China.,Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, China.,Tianjin Key Laboratory of Microbial Functional Genomics, Tianjin, China
| | - Shaomeng Wang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, China.,Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, China
| | - Jianxiao Huang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, China.,Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, China
| | - Zhiqiu Yin
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, China.,Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, China
| | - Lingyan Jiang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, China.,Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, China.,Tianjin Key Laboratory of Microbial Functional Genomics, Tianjin, China
| | - Wenqi Hou
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, China.,Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, China
| | - Xiaomin Li
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, China.,Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, China
| | - Lu Feng
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, China.,Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, China.,Tianjin Key Laboratory of Microbial Functional Genomics, Tianjin, China.,State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, China.,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, China
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16
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Strategies for Biofilm Inhibition and Virulence Attenuation of Foodborne Pathogen-Escherichia coli O157:H7. Curr Microbiol 2017; 74:1477-1489. [DOI: 10.1007/s00284-017-1314-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 07/19/2017] [Indexed: 10/19/2022]
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17
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Bose T, Venkatesh KV, Mande SS. Computational Analysis of Host-Pathogen Protein Interactions between Humans and Different Strains of Enterohemorrhagic Escherichia coli. Front Cell Infect Microbiol 2017; 7:128. [PMID: 28469995 PMCID: PMC5395655 DOI: 10.3389/fcimb.2017.00128] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 03/28/2017] [Indexed: 01/18/2023] Open
Abstract
Serotype O157:H7, an enterohemorrhagic Escherichia coli (EHEC), is known to cause gastrointestinal and systemic illnesses ranging from diarrhea and hemorrhagic colitis to potentially fatal hemolytic uremic syndrome. Specific genetic factors like ompA, nsrR, and LEE genes are known to play roles in EHEC pathogenesis. However, these factors are not specific to EHEC and their presence in several non-pathogenic strains indicates that additional factors are involved in pathogenicity. We propose a comprehensive effort to screen for such potential genetic elements, through investigation of biomolecular interactions between E. coli and their host. In this work, an in silico investigation of the protein–protein interactions (PPIs) between human cells and four EHEC strains (viz., EDL933, Sakai, EC4115, and TW14359) was performed in order to understand the virulence and host-colonization strategies of these strains. Potential host–pathogen interactions (HPIs) between human cells and the “non-pathogenic” E. coli strain MG1655 were also probed to evaluate whether and how the variations in the genomes could translate into altered virulence and host-colonization capabilities of the studied bacterial strains. Results indicate that a small subset of HPIs are unique to the studied pathogens and can be implicated in virulence. This subset of interactions involved E. coli proteins like YhdW, ChuT, EivG, and HlyA. These proteins have previously been reported to be involved in bacterial virulence. In addition, clear differences in lineage and clade-specific HPI profiles could be identified. Furthermore, available gene expression profiles of the HPI-proteins were utilized to estimate the proportion of proteins which may be involved in interactions. We hypothesized that a cumulative score of the ratios of bound:unbound proteins (involved in HPIs) would indicate the extent of colonization. Thus, we designed the Host Colonization Index (HCI) measure to determine the host colonization potential of the E. coli strains. Pathogenic strains of E. coli were observed to have higher HCIs as compared to a non-pathogenic laboratory strain. However, no significant differences among the HCIs of the two pathogenic groups were observed. Overall, our findings are expected to provide additional insights into EHEC pathogenesis and are likely to aid in designing alternate preventive and therapeutic strategies.
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Affiliation(s)
- Tungadri Bose
- Bio-Sciences R&D Division, TCS Innovation Labs, Tata Consultancy Services LimitedPune, India.,Department of Chemical Engineering, Indian Institute of Technology BombayMumbai, India
| | - K V Venkatesh
- Department of Chemical Engineering, Indian Institute of Technology BombayMumbai, India
| | - Sharmila S Mande
- Bio-Sciences R&D Division, TCS Innovation Labs, Tata Consultancy Services LimitedPune, India
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18
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Campion A, Morrissey R, Field D, Cotter PD, Hill C, Ross RP. Use of enhanced nisin derivatives in combination with food-grade oils or citric acid to control Cronobacter sakazakii and Escherichia coli O157:H7. Food Microbiol 2017; 65:254-263. [PMID: 28400011 DOI: 10.1016/j.fm.2017.01.020] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 01/27/2017] [Accepted: 01/30/2017] [Indexed: 11/15/2022]
Abstract
Cronobacter sakazakii and Escherichia coli O157:H7 are well known food-borne pathogens that can cause severe disease. The identification of new alternatives to heating to control these pathogens in foods, while reducing the impact on organoleptic properties and nutritional value, is highly desirable. In this study, nisin and its bioengineered variants, nisin V and nisin S29A, are used alone, or in combination with plant essential oils (thymol, carvacrol and trans-cinnamaldehyde) or citric acid, with a view to controlling C. sakazakii and E. coli O157:H7 in laboratory-based assays and model food systems. The use of nisin variants (30 μM) with low concentrations of thymol (0.015%), carvacrol (0.03%) and trans-cinnamaldehyde (0.035%) resulted in extended lag phases of growth compared to those for corresponding nisin A-essential oil combinations. Furthermore, nisin variants (60 μM) used in combination with carvacrol (0.03%) significantly reduced viable counts of E. coli O157:H7 (3-log) and C. sakazakii (4-log) compared to nisin A-carvacrol treatment. Importantly, this increased effectiveness translated into food. More specifically, sub-inhibitory concentrations of nisin variants and carvacrol caused complete inactivation of E. coli O157:H7 in apple juice within 3 h at room temperature compared to that of the equivalent nisin A combination. Furthermore, combinations of commercial Nisaplin and the food additive citric acid reduced C. sakazakii numbers markedly in infant formula within the same 3 h period. These results highlight the potential benefits of combining nisin and variants thereof with carvacrol and/or citric acid for the inhibition of Gram negative food-borne pathogens.
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Affiliation(s)
- Alicia Campion
- School of Microbiology, University College Cork, Cork, Ireland
| | - Ruth Morrissey
- School of Microbiology, University College Cork, Cork, Ireland; APC Microbiome Institute, University College Cork, Cork, Ireland
| | - Des Field
- School of Microbiology, University College Cork, Cork, Ireland
| | - Paul D Cotter
- APC Microbiome Institute, University College Cork, Cork, Ireland; Teagasc, Moorepark Food Research Centre, Fermoy, Co. Cork, Ireland.
| | - Colin Hill
- School of Microbiology, University College Cork, Cork, Ireland; APC Microbiome Institute, University College Cork, Cork, Ireland.
| | - R Paul Ross
- APC Microbiome Institute, University College Cork, Cork, Ireland; College of Science, Engineering and Food Science, University College Cork, Cork, Ireland
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19
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Chen J, Tang J, Tang C, Shi H, Gu H, Lu X. Growth and Volatile Compounds ofEscherichia coliO157:H7 on Irradiated Pork. J FOOD QUALITY 2016. [DOI: 10.1111/jfq.12254] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Affiliation(s)
- Juan Chen
- College of life Science and Technology; Southwest University for Nationalities; Chengdu 610041 China
| | - Junni Tang
- College of life Science and Technology; Southwest University for Nationalities; Chengdu 610041 China
| | - Cheng Tang
- College of life Science and Technology; Southwest University for Nationalities; Chengdu 610041 China
| | - Hui Shi
- College of life Science and Technology; Southwest University for Nationalities; Chengdu 610041 China
| | - Huaiyin Gu
- College of life Science and Technology; Southwest University for Nationalities; Chengdu 610041 China
| | - Xiaozhu Lu
- College of life Science and Technology; Southwest University for Nationalities; Chengdu 610041 China
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20
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Moriarty RD, Cox A, McCall M, Smith SGJ, Cox D. Escherichia coli induces platelet aggregation in an FcγRIIa-dependent manner. J Thromb Haemost 2016; 14:797-806. [PMID: 26669970 DOI: 10.1111/jth.13226] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 11/30/2015] [Indexed: 12/20/2022]
Abstract
BACKGROUND The discovery of pathogen-recognition receptors such as Toll-like receptors on platelets has led to the emergence of the concept of platelets as important components of the host response to infection. Escherichia coli (E. coli)-mediated sepsis is a serious illness characterized by the occurrence of thrombocytopenia. Whereas there has been a wealth of research on platelet activation by Gram-positive bacteria, little is known about the mechanisms associated with Gram-negative bacteria-induced platelet activation with Gram-negative bacteria. OBJECTIVES To determine the mechanisms by which Gram-negative E. coli induces platelet aggregation. METHODS Induction of platelet aggregation with E. coli strain O157:H7 was tested in platelet-rich plasma (PRP), washed platelets, and serum depleted of complement factors. Platelet inhibitors (against αII b β3 , glycoprotein Ibα and FcγRIIa) were used. Platelet thromboxane synthesis was analyzed after E. coli stimulation. Cell binding assays were used to assess the ability of E. coli to support platelet adhesion. Trypsinization was used to determine the role of E. coli surface proteins. RESULTS AND CONCLUSION E. coli-induced aggregation in PRP was donor-dependent. E. coli O157:H7 induced aggregation with a lag time of 6.9 ± 1.3 min in an αII b β3 -dependent and FcγRIIa-dependent manner. Furthermore, this interaction was enhanced by the presence of complement, and was dependent on thromboxane synthesis. These results show E. coli to be a potent inducer of platelet aggregation.
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Affiliation(s)
- R D Moriarty
- Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - A Cox
- Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - M McCall
- Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - S G J Smith
- Department of Clinical Microbiology, School of Medicine, Trinity College Dublin, Dublin, Ireland
| | - D Cox
- Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, Ireland
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21
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Tyska MJ. Brush Border Destruction by Enterohemorrhagic Escherichia coli (EHEC): New Insights From Organoid Culture. Cell Mol Gastroenterol Hepatol 2015; 2:7-8. [PMID: 28174702 PMCID: PMC4980709 DOI: 10.1016/j.jcmgh.2015.11.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Affiliation(s)
- Matthew J. Tyska
- Correspondence Address correspondence to: Matthew J. Tyska, PhD, Department of Cell and Developmental Biology, Vanderbilt Epithelial Biology Center, Vanderbilt University School of Medicine, 3154 MRB III, PMB 407935, 465 21st Avenue South, Nashville, Tennessee 37240-7935.Department of Cell and Developmental BiologyVanderbilt Epithelial Biology CenterVanderbilt University School of Medicine3154 MRB IIIPMB 407935465 21st Avenue SouthNashvilleTennessee 37240-7935
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22
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Desin TS, Townsend HG, Potter AA. Antibodies Directed against Shiga-Toxin Producing Escherichia coli Serotype O103 Type III Secreted Proteins Block Adherence of Heterologous STEC Serotypes to HEp-2 Cells. PLoS One 2015; 10:e0139803. [PMID: 26451946 PMCID: PMC4599963 DOI: 10.1371/journal.pone.0139803] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 09/17/2015] [Indexed: 11/25/2022] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) serotype O103 is a zoonotic pathogen that is capable of causing hemorrhagic colitis and hemolytic uremic syndrome (HUS) in humans. The main animal reservoir for STEC is ruminants and hence reducing the levels of this pathogen in cattle could ultimately lower the risk of STEC infection in humans. During the process of infection, STECO103 uses a Type III Secretion System (T3SS) to secrete effector proteins (T3SPs) that result in the formation of attaching and effacing (A/E) lesions. Vaccination of cattle with STEC serotype O157 T3SPs has previously been shown to be effective in reducing shedding of STECO157 in a serotype-specific manner. In this study, we tested the ability of rabbit polyclonal sera against individual STECO103 T3SPs to block adherence of the organism to HEp-2 cells. Our results demonstrate that pooled sera against EspA, EspB, EspF, NleA and Tir significantly lowered the adherence of STECO103 relative to pre-immune sera. Likewise, pooled anti-STECO103 sera were also able to block adherence by STECO157. Vaccination of mice with STECO103 recombinant proteins induced strong IgG antibody responses against EspA, EspB, NleA and Tir but not against EspF. However, the vaccine did not affect fecal shedding of STECO103 compared to the PBS vaccinated group over the duration of the experiment. Cross reactivity studies using sera against STECO103 recombinant proteins revealed a high degree of cross reactivity with STECO26 and STECO111 proteins implying that sera against STECO103 proteins could potentially provide neutralization of attachment to epithelial cells by heterologous STEC serotypes.
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Affiliation(s)
- Taseen S. Desin
- Vaccine & Infectious Disease Organization–International Vaccine Center, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
- * E-mail:
| | - Hugh G. Townsend
- Vaccine & Infectious Disease Organization–International Vaccine Center, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Andrew A. Potter
- Vaccine & Infectious Disease Organization–International Vaccine Center, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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23
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Abstract
Shiga toxin-producing Escherichia coli (STEC) is among the common causes of foodborne gastroenteritis. STEC is defined by the production of specific toxins, but within this pathotype there is a diverse group of organisms. This diversity has important consequences for understanding the pathogenesis of the organism, as well as for selecting the optimum strategy for diagnostic testing in the clinical laboratory. This review includes discussions of the mechanisms of pathogenesis, the range of manifestations of infection, and the several different methods of laboratory detection of Shiga toxin-producing E coli.
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