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Wang F, Sun H, Kang C, Yan J, Chen J, Feng X, Yang B. Genomic island-encoded regulatory proteins in enterohemorrhagic Escherichia coli O157:H7. Virulence 2024; 15:2313407. [PMID: 38357901 PMCID: PMC10877973 DOI: 10.1080/21505594.2024.2313407] [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: 10/24/2023] [Accepted: 01/23/2024] [Indexed: 02/16/2024] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) is an important zoonotic pathogen that is a major cause of foodborne diseases in most developed and developing countries and can cause uncomplicated diarrhoea, haemorrhagic colitis, and haemolytic uraemic syndrome. O islands (OIs), which are unique genomic islands in EHEC O157:H7, are composed of 177 isolated genomic features and harbour 26% of the total genes that are absent in the non-pathogenic E. coli K-12 genome. In the last twenty years, many OI-encoded proteins have been characterized, including proteins regulating virulence, motility, and acid resistance. Given the critical role of regulatory proteins in the systematic and hierarchical regulation of bacterial biological processes, this review summarizes the OI-encoded regulatory proteins in EHEC O157:H7 characterized to date, emphasizing OI-encoded regulatory proteins for bacterial virulence, motility, and acid resistance. This summary will be significant for further exploration and understanding of the virulence and pathogenesis of EHEC O157:H7.
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Affiliation(s)
- Fang Wang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, China
- Intensive Care Unit, Shenzhen Institute of Translational Medicine, Health Science Center, The First Affiliated Hospital of Shenzhen University, Shenzhen, China
| | - Hongmin Sun
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, China
| | - Chenbo Kang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, China
| | - Jun Yan
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, China
| | - Jingnan Chen
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, China
| | - Xuequan Feng
- Tianjin First Central Hospital, Nankai University, Tianjin, China
| | - Bin Yang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, China
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2
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Zhu L, Liang Z, Xu Y, Chen Z, Wang J, Zhou L. Ultrasensitive and Rapid Visual Detection of Escherichia coli O157:H7 Based on RAA-CRISPR/Cas12a System. BIOSENSORS 2023; 13:659. [PMID: 37367024 DOI: 10.3390/bios13060659] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 06/12/2023] [Accepted: 06/14/2023] [Indexed: 06/28/2023]
Abstract
Escherichia coli (E. coli) O157:H7 is a major foodborne and waterborne pathogen that can threaten human health. Due to its high toxicity at low concentrations, it is crucial to establish a time-saving and highly sensitive in situ detection method. Herein, we developed a rapid, ultrasensitive, and visualized method for detecting E. coli O157:H7 based on a combination of Recombinase-Aided Amplification (RAA) and CRISPR/Cas12a technology. The CRISPR/Cas12a-based system was pre-amplified using the RAA method, which showed high sensitivity and enabled detecting as low as ~1 CFU/mL (fluorescence method) and 1 × 102 CFU/mL (lateral flow assay) of E. coli O157:H7, which was much lower than the detection limit of the traditional real-time PCR technology (103 CFU/mL) and ELISA (104~107 CFU/mL). In addition, we demonstrated that this method still has good applicability in practical samples by simulating the detection in real milk and drinking water samples. Importantly, our RAA-CRISPR/Cas12a detection system could complete the overall process (including extraction, amplification, and detection) within 55 min under optimized conditions, which is faster than most other reported sensors, which take several hours to several days. The signal readout could also be visualized by fluorescence generated with a handheld UV lamp or a naked-eye-detected lateral flow assay depending on the DNA reporters used. Because of the advantages of being fast, having high sensitivity, and not requiring sophisticated equipment, this method has a promising application prospect for in situ detection of trace amounts of pathogens.
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Affiliation(s)
- Lishan Zhu
- Institute of Environmental Research at Greater Bay Area, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou 510006, China
| | - Zhenda Liang
- Institute of Environmental Research at Greater Bay Area, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou 510006, China
| | - Yongtao Xu
- Institute of Environmental Research at Greater Bay Area, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou 510006, China
| | - Zhiquan Chen
- Institute of Environmental Research at Greater Bay Area, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou 510006, China
| | - Jiasi Wang
- Guangdong Provincial Key Laboratory of Sensor Technology and Biomedical Instrument, School of Biomedical Engineering, Shenzhen Campus of Sun Yat-Sen University, Shenzhen 518107, China
| | - Li Zhou
- Institute of Environmental Research at Greater Bay Area, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou 510006, China
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3
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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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4
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Eugenol, citral, and hexanal, alone or in combination with heat, affect viability, biofilm formation, and swarming on Shiga-toxin-producing Escherichia coli. Food Sci Biotechnol 2021; 30:599-607. [PMID: 33936852 DOI: 10.1007/s10068-021-00887-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 02/03/2021] [Accepted: 02/05/2021] [Indexed: 10/21/2022] Open
Abstract
Shiga-toxin-producing Escherichia coli strains are pathogenic for humans and cause mild to severe illnesses. In this study, the antimicrobial effect of citral, eugenol, and hexanal in combination with heat shock (HS) was evaluated in terms of the growth, biofilm formation, swarming, and expression of virulence genes of STEC serotypes (O157:H7, O103, O111, and O26). Eugenol was the most effective compound against the growth of E. coli strains (MBC = 0.58 to 0.73 mg/mL), followed by citral (MBC = 0.86 to 1.26 mg/mL) and hexanal (MBC = 2.24 to 2.52 mg/mL). Biofilm formation and swarming motility have great variability between STEC strains. Natural compounds-alone or combined with HS-inhibited biofilm formation; however, swarming motility was induced by most treatments. The expression of the studied genes during biofilm formation and swarming under natural antimicrobials was affected but not in a uniform pattern. These treatments could be used to control contamination of STEC and inhibit biofilm formation.
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5
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Khan F, Tabassum N, Pham DTN, Oloketuyi SF, Kim YM. Molecules involved in motility regulation in Escherichia coli cells: a review. BIOFOULING 2020; 36:889-908. [PMID: 33028083 DOI: 10.1080/08927014.2020.1826939] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 09/14/2020] [Accepted: 09/15/2020] [Indexed: 06/11/2023]
Abstract
The initial colonization of the host organism by commensal, probiotic, and pathogenic Escherichia coli strains is an important step in the development of infections and biofilms. Sensing and colonization of host cell surfaces are governed by flagellar and fimbriae/pili appendages, respectively. Biofilm formation confers great advantages on pathogenic E. coli cells such as protection against the host immune system, antimicrobial agents, and several environmental stress factors. The transition from planktonic to sessile physiological states involves several signaling cascades and factors responsible for the regulation of flagellar motility in E. coli cells. These regulatory factors have thus become important targets to control pathogenicity. Hence, attenuation of flagellar motility is considered a potential therapy against pathogenic E. coli. The present review describes signaling pathways and proteins involved in direct or indirect regulation of flagellar motility. Furthermore, application strategies for antimotility natural or synthetic compounds are discussed also.
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Affiliation(s)
- Fazlurrahman Khan
- Institute of Food Science, Pukyong National University, Busan, Republic of Korea
| | - Nazia Tabassum
- Industrial Convergence Bionix Engineering, Pukyong National University, Busan, Republic of Korea
| | - Dung Thuy Nguyen Pham
- Department of Food Science and Technology, Pukyong National University, Busan, Republic of Korea
| | | | - Young-Mog Kim
- Institute of Food Science, Pukyong National University, Busan, Republic of Korea
- Department of Food Science and Technology, Pukyong National University, Busan, Republic of Korea
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6
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Liu Y, Liu B, Yang P, Wang T, Chang Z, Wang J, Wang Q, Li W, Wu J, Huang D, Jiang L, Yang B. LysR-type transcriptional regulator OvrB encoded in O island 9 drives enterohemorrhagic Escherichia coli O157:H7 virulence. Virulence 2019; 10:783-792. [PMID: 31502495 PMCID: PMC6768210 DOI: 10.1080/21505594.2019.1661721] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) O157:H7 (O157) is a major foodborne pathogen that causes severe illness in humans worldwide. The genome of O157 contains 177 genomic islands known as O islands (OIs), including Shiga toxin-converting phages (OI-45 and OI-93) and the locus for enterocyte effacement (LEE) pathogenicity island (OI-148). However, most genes in OIs are uncharacterized and code for unknown functions. In this study, we demonstrated, for the first time, that OI-9 encodes a novel transcriptional activator, Z0346 (named OvrB), which is required for bacterial adherence to host cells and LEE gene expression in O157. OvrB directly binds to the promoter region of LEE1 and activates the transcription of ler (encoding a master regulator of LEE genes), which in turn activates LEE1–5 genes to promote O157 adherence. Furthermore, mouse oral infection assays showed that OvrB promotes O157 colonization in the mouse intestine. Finally, OvrB is shown to be a widespread transcriptional activator of virulence genes in other enterohemorrhagic and enteropathogenic Escherichia coli serotypes. Our work significantly expands the understanding of bacterial virulence control and provides new evidence suggesting that horizontally transferred regulator genes mediate LEE gene expression.
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Affiliation(s)
- Yutao Liu
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA , Tianjin , P. R. China.,The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education , Tianjin , P. R. China
| | - Bin Liu
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA , Tianjin , P. R. China.,The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education , Tianjin , P. R. China
| | - Pan Yang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA , Tianjin , P. R. China.,The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education , Tianjin , P. R. China
| | - Ting Wang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA , Tianjin , P. R. China.,The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education , Tianjin , P. R. China
| | - Zhanhe Chang
- School of Biomedical Engineering, Tianjin Medical University , Tianjin , P. R. China
| | - Junyue Wang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA , Tianjin , P. R. China.,The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education , Tianjin , P. R. China
| | - Qian Wang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA , Tianjin , P. R. China.,The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education , Tianjin , P. R. China
| | - Wendi Li
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA , Tianjin , P. R. China.,The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education , Tianjin , P. R. China
| | - Jialin Wu
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA , Tianjin , P. R. China.,The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education , Tianjin , P. R. China
| | - Di Huang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA , Tianjin , P. R. China.,The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education , Tianjin , P. R. China
| | - Lingyan Jiang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA , Tianjin , P. R. China.,The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education , Tianjin , P. R. China
| | - Bin Yang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA , Tianjin , P. R. China.,The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education , Tianjin , P. R. China
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7
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Tovaglieri A, Sontheimer-Phelps A, Geirnaert A, Prantil-Baun R, Camacho DM, Chou DB, Jalili-Firoozinezhad S, de Wouters T, Kasendra M, Super M, Cartwright MJ, Richmond CA, Breault DT, Lacroix C, Ingber DE. Species-specific enhancement of enterohemorrhagic E. coli pathogenesis mediated by microbiome metabolites. MICROBIOME 2019; 7:43. [PMID: 30890187 PMCID: PMC6425591 DOI: 10.1186/s40168-019-0650-5] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Accepted: 02/21/2019] [Indexed: 05/24/2023]
Abstract
BACKGROUND Species-specific differences in tolerance to infection are exemplified by the high susceptibility of humans to enterohemorrhagic Escherichia coli (EHEC) infection, whereas mice are relatively resistant to this pathogen. This intrinsic species-specific difference in EHEC infection limits the translation of murine research to human. Furthermore, studying the mechanisms underlying this differential susceptibility is a difficult problem due to complex in vivo interactions between the host, pathogen, and disparate commensal microbial communities. RESULTS We utilize organ-on-a-chip (Organ Chip) microfluidic culture technology to model damage of the human colonic epithelium induced by EHEC infection, and show that epithelial injury is greater when exposed to metabolites derived from the human gut microbiome compared to mouse. Using a multi-omics approach, we discovered four human microbiome metabolites-4-methyl benzoic acid, 3,4-dimethylbenzoic acid, hexanoic acid, and heptanoic acid-that are sufficient to mediate this effect. The active human microbiome metabolites preferentially induce expression of flagellin, a bacterial protein associated with motility of EHEC and increased epithelial injury. Thus, the decreased tolerance to infection observed in humans versus other species may be due in part to the presence of compounds produced by the human intestinal microbiome that actively promote bacterial pathogenicity. CONCLUSION Organ-on-chip technology allowed the identification of specific human microbiome metabolites modulating EHEC pathogenesis. These identified metabolites are sufficient to increase susceptibility to EHEC in our human Colon Chip model and they contribute to species-specific tolerance. This work suggests that higher concentrations of these metabolites could be the reason for higher susceptibility to EHEC infection in certain human populations, such as children. Furthermore, this research lays the foundation for therapeutic-modulation of microbe products in order to prevent and treat human bacterial infection.
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Affiliation(s)
- Alessio Tovaglieri
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, 02115, USA
- Department of Health Sciences and Technology, ETH Zurich, 8092, Zurich, Switzerland
| | - Alexandra Sontheimer-Phelps
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, 02115, USA
- Department of Biology, University of Freiburg, 79085, Freiburg, Germany
| | - Annelies Geirnaert
- Department of Health Sciences and Technology, ETH Zurich, 8092, Zurich, Switzerland
| | - Rachelle Prantil-Baun
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, 02115, USA
| | - Diogo M Camacho
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, 02115, USA
| | - David B Chou
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, 02115, USA
- Department of Pathology, Massachusetts General Hospital, Boston, MA, 02115, USA
| | - Sasan Jalili-Firoozinezhad
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, 02115, USA
- Department of Bioengineering and iBB, Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, 1649-004, Lisbon, Portugal
| | - Tomás de Wouters
- Department of Health Sciences and Technology, ETH Zurich, 8092, Zurich, Switzerland
| | - Magdalena Kasendra
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, 02115, USA
- Present Address: Emulate Inc., 27 Drydock Avenue, Boston, MA, 02210, USA
| | - Michael Super
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, 02115, USA
| | - Mark J Cartwright
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, 02115, USA
| | - Camilla A Richmond
- Division of Gastroenterology, Boston Children's Hospital, Boston, MA, 02115, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, 02115, USA
- Harvard Stem Cell Institute, Harvard University, Boston, MA, 02139, USA
| | - David T Breault
- Department of Pediatrics, Harvard Medical School, Boston, MA, 02115, USA
- Harvard Stem Cell Institute, Harvard University, Boston, MA, 02139, USA
- Division of Endocrinology, Boston Children's Hospital, Boston, MA, 02115, USA
| | - Christophe Lacroix
- Department of Health Sciences and Technology, ETH Zurich, 8092, Zurich, Switzerland
| | - Donald E Ingber
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, 02115, USA.
- Vascular Biology Program and Department of Surgery, Boston Children's Hospital and Harvard Medical School, Boston, MA, 02115, USA.
- Harvard John A. Paulson School of Engineering and Applied Sciences, Cambridge, MA, 02139, USA.
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8
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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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9
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Zhang Z, Kukita C, Humayun MZ, Saier MH. Environment-directed activation of the Escherichia coliflhDC operon by transposons. MICROBIOLOGY-SGM 2017; 163:554-569. [PMID: 28100305 DOI: 10.1099/mic.0.000426] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The flagellar system in Escherichia coli K12 is expressed under the control of the flhDC-encoded master regulator FlhDC. Transposition of insertion sequence (IS) elements to the upstream flhDC promoter region up-regulates transcription of this operon, resulting in a more rapid motility. Wang and Wood (ISME J 2011;5:1517-1525) provided evidence that insertion of IS5 into upstream activating sites occurs at higher rates in semi-solid agar media in which swarming behaviour is allowed as compared with liquid or solid media where swarming cannot occur. We confirm this conclusion and show that three IS elements, IS1, IS3 and IS5, transpose to multiple upstream sites within a 370 bp region of the flhDC operon control region. Hot spots for IS insertion correlate with positions of stress-induced DNA duplex destabilization (SIDD). We show that IS insertion occurs at maximal rates in 0.24 % agar, with rates decreasing dramatically with increasing or decreasing agar concentrations. In mixed cultures, we show that these mutations preferentially arise from the wild-type parent at frequencies of up to 3×10-3 cell-1 day-1 when the inoculated parental and co-existing IS-activated mutant cells are entering the stationary growth phase. We rigorously show that the apparent increased mutation frequencies cannot be accounted for by increased swimming or by increased growth under the selective conditions used. Thus, our data are consistent with the possibility that appropriate environmental conditions, namely those that permit but hinder flagellar rotation, result in the activation of a mutational pathway that involves IS element insertion upstream of the flhDC operon.
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Affiliation(s)
- Zhongge Zhang
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, USA
| | - Chika Kukita
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, USA
| | - M Zafri Humayun
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School, Newark, NJ 07101-1709, USA
| | - Milton H Saier
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, USA
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10
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Baskaran SA, Kollanoor-Johny A, Nair MS, Venkitanarayanan K. Efficacy of Plant-Derived Antimicrobials in Controlling Enterohemorrhagic Escherichia coli Virulence In Vitro. J Food Prot 2016; 79:1965-1970. [PMID: 28221905 DOI: 10.4315/0362-028x.jfp-16-104] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Escherichia coli O157:H7 is a major foodborne pathogen that can cause serious human illness characterized by hemorrhagic diarrhea and kidney failure. The pathology of enterohemorrhagic E. coli O157:H7 (EHEC) infection is primarily mediated by verotoxins, which bind to the globotriaosylceramide receptor on host cells. Antibiotics are contraindicated for treating EHEC infection because they lead to increased verotoxin release, thereby increasing the risk of renal failure and death in patients. Thus, alternative strategies are needed for controlling EHEC infections in humans. This study investigated the effect of subinhibitory concentrations of five plant-derived antimicrobial agents (PDAs) that are generally considered as safe, i.e., trans-cinnamaldehyde, eugenol, carvacrol, thymol, and β-resorcylic acid, on EHEC motility, adhesion to human intestinal epithelial cells, verotoxin production, and virulence gene expression. All tested PDAs reduced EHEC motility and attachment to human intestinal epithelial cells (P < 0.05) and decreased verotoxin synthesis by EHEC. The reverse transcription real-time PCR data revealed that PDAs decreased the expression of critical virulence genes in EHEC (P < 0.05). The results collectively suggest that these PDAs could be used to reduce EHEC virulence, but follow-up studies in animal models are necessary to validate these findings.
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Affiliation(s)
- Sangeetha Ananda Baskaran
- Department of Veterinary Public Health & Epidemiology, Veterinary College & Research Institute, Orathanadu, Tamil Nadu, India 614 625
| | - Anup Kollanoor-Johny
- Department of Animal Science, University of Minnesota, St. Paul, Minnesota 55108, USA
| | - Meera Surendran Nair
- Department of Animal Science, University of Connecticut, Storrs, Connecticut 06269, USA
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Lackraj T, Kim JI, Tran SL, Barnett Foster DE. Differential modulation of flagella expression in enterohaemorrhagic Escherichia coli O157: H7 by intestinal short-chain fatty acid mixes. MICROBIOLOGY-SGM 2016; 162:1761-1772. [PMID: 27535670 DOI: 10.1099/mic.0.000357] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
During passage through the gastrointestinal tract, enterohaemorrhagic Escherichia coli (EHEC) encounters numerous stresses, each producing unique antimicrobial conditions. Beyond surviving these stresses, EHEC may also use them as cues about the local microenvironment to modulate its virulence. Of particular interest is how exposure to changing concentrations of short-chain fatty acids (SCFAs) associated with passage through the small and large intestines affects EHEC virulence, as well as flagella expression and motility specifically. In this study, we investigate the impact of exposure to SCFA mixes simulating concentrations and compositions within the small and large intestines on EHEC flagella expression and function. Using a combination of DNA microarray, quantitative real-time PCR, immunoblot analysis, flow cytometry and motility assays, we show that there is a marked, significant upregulation of flagellar genes, the flagellar protein, FliC, and motility when EHEC is exposed to SCFA mixes representative of the small intestine. By contrast, when EHEC is exposed to SCFA mixes representative of the large intestine, there is a significant downregulation of flagellar genes, FliC and motility. Our results demonstrate that EHEC modulates flagella expression and motility in response to SCFAs, with differential responses associated with SCFA mixes typical of the small and large intestines. This research contributes to our understanding of how EHEC senses and responds to host environmental signals and the mechanisms it uses to successfully infect the human host. Significantly, it also suggests that EHEC is using this key gastrointestinal chemical signpost to cue changes in flagella expression and motility in different locations within the host intestinal tract.
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Affiliation(s)
- Tracy Lackraj
- Department of Chemistry and Biology, Ryerson University, Toronto, ON, Canada
| | - Jee In Kim
- Department of Chemistry and Biology, Ryerson University, Toronto, ON, Canada
| | - Seav-Ly Tran
- Department of Chemistry and Biology, Ryerson University, Toronto, ON, Canada
| | - Debora E Barnett Foster
- Faculty of Dentistry, University of Toronto, Toronto, ON, Canada.,Department of Chemistry and Biology, Ryerson University, Toronto, ON, Canada.,Program for Molecular Structure and Function, Research Institute, Hospital for Sick Children, Toronto, ON, Canada
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12
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Abstract
Proteus mirabilis is a Gram-negative bacterium and is well known for its ability to robustly swarm across surfaces in a striking bulls'-eye pattern. Clinically, this organism is most frequently a pathogen of the urinary tract, particularly in patients undergoing long-term catheterization. This review covers P. mirabilis with a focus on urinary tract infections (UTI), including disease models, vaccine development efforts, and clinical perspectives. Flagella-mediated motility, both swimming and swarming, is a central facet of this organism. The regulation of this complex process and its contribution to virulence is discussed, along with the type VI-secretion system-dependent intra-strain competition, which occurs during swarming. P. mirabilis uses a diverse set of virulence factors to access and colonize the host urinary tract, including urease and stone formation, fimbriae and other adhesins, iron and zinc acquisition, proteases and toxins, biofilm formation, and regulation of pathogenesis. While significant advances in this field have been made, challenges remain to combatting complicated UTI and deciphering P. mirabilis pathogenesis.
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13
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Transcriptional analysis of the MrpJ network: modulation of diverse virulence-associated genes and direct regulation of mrp fimbrial and flhDC flagellar operons in Proteus mirabilis. Infect Immun 2015; 83:2542-56. [PMID: 25847961 DOI: 10.1128/iai.02978-14] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 03/29/2015] [Indexed: 01/14/2023] Open
Abstract
The enteric bacterium Proteus mirabilis is associated with a significant number of catheter-associated urinary tract infections (UTIs). Strict regulation of the antagonistic processes of adhesion and motility, mediated by fimbriae and flagella, respectively, is essential for disease progression. Previously, the transcriptional regulator MrpJ, which is encoded by the mrp fimbrial operon, has been shown to repress both swimming and swarming motility. Here we show that MrpJ affects an array of cellular processes beyond adherence and motility. Microarray analysis found that expression of mrpJ mimicking levels observed during UTIs leads to differential expression of 217 genes related to, among other functions, bacterial virulence, type VI secretion, and metabolism. We probed the molecular mechanism of transcriptional regulation by MrpJ using transcriptional reporters and chromatin immunoprecipitation (ChIP). Binding of MrpJ to two virulence-associated target gene promoters, the promoters of the flagellar master regulator flhDC and mrp itself, appears to be affected by the condensation state of the native chromosome, although both targets share a direct MrpJ binding site proximal to the transcriptional start. Furthermore, an mrpJ deletion mutant colonized the bladders of mice at significantly lower levels in a transurethral model of infection. Additionally, we observed that mrpJ is widely conserved in a collection of recent clinical isolates. Altogether, these findings support a role of MrpJ as a global regulator of P. mirabilis virulence.
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Xu Y, Xu X, Lan R, Xiong Y, Ye C, Ren Z, Liu L, Zhao A, Wu LF, Xu J. An O island 172 encoded RNA helicase regulates the motility of Escherichia coli O157:H7. PLoS One 2013; 8:e64211. [PMID: 23785398 PMCID: PMC3681947 DOI: 10.1371/journal.pone.0064211] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Accepted: 04/10/2013] [Indexed: 12/28/2022] Open
Abstract
Enterohaemorrhagic Escherichia coli (EHEC) O157:H7 is a major cause of zoonotic food- and water-borne intestinal infections worldwide with clinical consequences ranging from mild diarrhoea to hemolytic uraemic syndrome. The genome of EHEC O157:H7 contains many regions of unique DNA that are referred to as O islands including the Shiga toxin prophages and pathogenicity islands encoding key virulence factors. However many of these O islands are of unknown function. In this study, genetic analysis was conducted on OI-172 which is a 44,434 bp genomic island with 27 open reading frames. Comparative genome analysis showed that O1-72 is a composite island with progressive gain of genes since O157:H7 evolved from its ancestral O55:H7. A partial OI-172 island was also found in 2 unrelated E. coli strains and 2 Salmonella strains. OI-172 encodes several putative helicases, one of which (Z5898) is a putative DEAH box RNA helicase. To investigate the function of Z5898, a deletion mutant (EDL933ΔZ5898) was constructed in the O157:H7 strain EDL933. Comparative proteomic analysis of the mutant with the wild-type EDL933 found that flagellin was down-regulated in the Z5898 mutant. Motility assay showed that EDL933ΔZ5898 migrated slower than the wild-type EDL933 and electron microscopy found no surface flagella. Quantitative reverse transcription PCR revealed that the fliC expression of EDL933ΔZ5898 was significantly lower while the expression of its upstream regulator gene, fliA, was not affected. Using a fliA and a fliC promoter - green fluorescent protein fusion contruct, Z5898 was found to affect only the fliC promoter activity. Therefore, Z5898 regulates the flagella based motility by exerting its effect on fliC. We conclude that OI-172 is a motility associated O island and hereby name it the MAO island.
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Affiliation(s)
- Yanmei Xu
- State Key Laboratory for Infectious Disease Prevention and Control (China CDC), Beijing, P R China
- National Institute of Communicable Diseases Control and Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, P R China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Xuefang Xu
- State Key Laboratory for Infectious Disease Prevention and Control (China CDC), Beijing, P R China
- National Institute of Communicable Diseases Control and Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, P R China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Ruiting Lan
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Yanwen Xiong
- State Key Laboratory for Infectious Disease Prevention and Control (China CDC), Beijing, P R China
- National Institute of Communicable Diseases Control and Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, P R China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Changyun Ye
- State Key Laboratory for Infectious Disease Prevention and Control (China CDC), Beijing, P R China
- National Institute of Communicable Diseases Control and Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, P R China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Zhihong Ren
- State Key Laboratory for Infectious Disease Prevention and Control (China CDC), Beijing, P R China
- National Institute of Communicable Diseases Control and Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, P R China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Li Liu
- Network Information Center, Institute of Microbiology, Chinese Academy of Sciences, Beijing, P R China
| | - Ailan Zhao
- State Key Laboratory for Infectious Disease Prevention and Control (China CDC), Beijing, P R China
- National Institute of Communicable Diseases Control and Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, P R China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Long-Fei Wu
- Laboratoire de Chimie Bactérienne, UPR9043, Université de la Méditerranée Aix-Marseille II, Institut de Microbiologie de la Méditerranée, CNRS, Marseille, France
| | - Jianguo Xu
- State Key Laboratory for Infectious Disease Prevention and Control (China CDC), Beijing, P R China
- National Institute of Communicable Diseases Control and Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, P R China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
- * E-mail:
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15
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Chekabab SM, Paquin-Veillette J, Dozois CM, Harel J. The ecological habitat and transmission ofEscherichia coliO157:H7. FEMS Microbiol Lett 2013; 341:1-12. [DOI: 10.1111/1574-6968.12078] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Revised: 12/17/2012] [Accepted: 01/03/2013] [Indexed: 01/29/2023] Open
Affiliation(s)
- Samuel Mohammed Chekabab
- Centre de Recherche en Infectiologie Porcine (CRIP); Faculté de Médecine Vétérinaire; Université de Montréal; Saint-Hyacinthe; QC; Canada
| | - Judith Paquin-Veillette
- Centre de Recherche en Infectiologie Porcine (CRIP); Faculté de Médecine Vétérinaire; Université de Montréal; Saint-Hyacinthe; QC; Canada
| | | | - Josée Harel
- Centre de Recherche en Infectiologie Porcine (CRIP); Faculté de Médecine Vétérinaire; Université de Montréal; Saint-Hyacinthe; QC; Canada
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