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Correa GB, Freire CA, Dibo M, Huerta-Cantillo J, Navarro-Garcia F, Barbosa AS, Elias WP, Moraes CTP. Plasmid-encoded toxin of Escherichia coli cleaves complement system proteins and inhibits complement-mediated lysis in vitro. Front Cell Infect Microbiol 2024; 14:1327241. [PMID: 38371299 PMCID: PMC10869522 DOI: 10.3389/fcimb.2024.1327241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 01/08/2024] [Indexed: 02/20/2024] Open
Abstract
Plasmid-encoded toxin (Pet) is an autotransporter protein of the serine protease autotransporters of Enterobacteriaceae (SPATE) family, important in the pathogenicity of Escherichia coli. The pet gene was initially found in the enteroaggregative E. coli (EAEC) virulence plasmid, pAA2. Although this virulence factor was initially described in EAEC, an intestinal E. coli pathotype, pet may also be present in other pathotypes, including extraintestinal pathogenic strains (ExPEC). The complement system is an important defense mechanism of the immune system that can be activated by invading pathogens. Proteases produced by pathogenic bacteria, such as SPATEs, have proteolytic activity and can cleave components of the complement system, promoting bacterial resistance to human serum. Considering these factors, the proteolytic activity of Pet and its role in evading the complement system were investigated. Proteolytic assays were performed by incubating purified components of the complement system with Pet and Pet S260I (a catalytic site mutant) proteins. Pet, but not Pet S260I, could cleave C3, C5 and C9 components, and also inhibited the natural formation of C9 polymers. Furthermore, a dose-dependent inhibition of ZnCl2-induced C9 polymerization in vitro was observed. E. coli DH5α survived incubation with human serum pre-treated with Pet. Therefore, Pet can potentially interfere with the alternative and the terminal pathways of the complement system. In addition, by cleaving C9, Pet may inhibit membrane attack complex (MAC) formation on the bacterial outer membrane. Thus, our data are suggestive of a role of Pet in resistance of E. coli to human serum.
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Affiliation(s)
| | | | - Miriam Dibo
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, Brazil
| | - Jazmin Huerta-Cantillo
- Department of Cell Biology, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (IPN), Mexico City, Mexico
| | - Fernando Navarro-Garcia
- Department of Cell Biology, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (IPN), Mexico City, Mexico
| | | | - Waldir P. Elias
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, Brazil
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2
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Izquierdo-Vega JA, Castillo-Juarez RJ, Sánchez-Gutiérrez M, Ares MA, De La Cruz MA. A Mini-Review of Enteroaggregative Escherichia coli with a Specific Target on the Virulence Factors Controlled by the AggR Master Regulator. Pol J Microbiol 2023; 72:347-354. [PMID: 37875068 PMCID: PMC10725161 DOI: 10.33073/pjm-2023-037] [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: 06/23/2023] [Accepted: 09/08/2023] [Indexed: 10/26/2023] Open
Abstract
Enteroaggregative Escherichia coli (EAEC) strains have been linked to several outbreaks of severe diarrhea around the world, and this bacterium is now commonly resistant to antibiotics. As part of the pathophysiology of EAEC, the characteristic pattern of adherence looks like stacked bricks on the intestinal epithelium. This phenotype depends on an aggregative adhesion plasmid (pAA), which codes for a regulatory protein named AggR. The AggR protein is a master regulator that transcriptionally actives the main virulence genes in this E. coli pathotype, such as those that encode the aggregative adhesion fimbriae, dispersin and its secretion apparatus, Aar regulatory protein, and type VI secretion system. Several reports have shown that AggR positively affects most EAEC virulence genes, functioning as a classic transcriptional activator in the promoter region of these genes, interacting with the RNA polymerase. This minireview article integrates the information about virulence determinants of EAEC controlled by the AggR regulator.
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Affiliation(s)
| | | | | | - Miguel A. Ares
- Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, Hospital de Pediatría, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, México City, México
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, México City, México
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3
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Chikhale RV, Prasad RS, de Resende PE, Akojwar NS, Purohit RA, Gurav SS, Sinha SK, Prasad SK. Analysing the impact of eriosematin E from Eriosema chinense Vogel. against different diarrhoeagenic pathovars of Escherichia coli using in silico and in vitro approach. J Biomol Struct Dyn 2023:1-12. [PMID: 37599503 DOI: 10.1080/07391102.2023.2246570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Accepted: 08/04/2023] [Indexed: 08/22/2023]
Abstract
Since diarrhoea is reportedly the third largest cause of fatality among kids, therefore it is considered to be one of the major areas of concerns among developing nations. The main causative agents of diarrhoea include Escherichia coli, Vibrio cholera, and Shigella spp where E. coli shares the maximum contribution. The roots of the plant Eriosema chinense Vogel. (Fabaceae) are traditionally used by the native tribes of Meghalaya, India to treat diarrhoea. From previous reports, the plant and its marker eriosematin E have been reported to have antidiarrhoeal potential against pathogenic and nonpathogenic diarrhoea. Therefore, the objective of the current investigation was to use in silico studies to determine the efficacy of eriosematin E against different diarrhoeagenic strains of E. coli. Six different pathovars of E. coli i.e. enteropathogenic E. coli (EPEC), enterotoxigenic E. coli (ETEC), enterohaemorrhagic E. coli (EHEC), enteroaggregative E. coli (EAEC), uropathogenic E. coli (UPEC) and enteroinvasive E. coli (EIEC) were subjected to docking simulation studies utilizing Glide module of Schrodinger Maestro 2018-1 MM Share Version. Based on the obtained binding energy and balance between H-bonding, hydrophobic, and salt bridge interactions eriosematin E was found to be most effective against EPEC followed by EAEC and ETEC, while UPEC and EHEC were moderately affected. The molecular dynamics studies suggested a higher affinity of eriosematin E towards heat-labile enterotoxin b-pentamer from ETEC. The in vitro antibacterial studies against the universal strain S. aureus 12981 and E. coli 10418 revealed the effectiveness of eriosematin E showing MIC values of ≥256 µg/mL.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Rupesh V Chikhale
- Department of Pharmaceutical and Biological Chemistry, School of Pharmacy, University College London, London, UK
| | - Rupali S Prasad
- Department of Pharmaceutical Sciences, Rashtrasant Tukadoji Maharaj Nagpur University, Nagpur, Maharashtra, India
| | | | - Natasha S Akojwar
- Department of Pharmaceutical Sciences, Rashtrasant Tukadoji Maharaj Nagpur University, Nagpur, Maharashtra, India
| | - Raksha A Purohit
- Department of Pharmaceutical Sciences, Rashtrasant Tukadoji Maharaj Nagpur University, Nagpur, Maharashtra, India
| | - Shailendra S Gurav
- Department of Pharmacognosy, Goa College of Pharmacy, Panaji, Goa University, Goa, India
| | - Saurabh K Sinha
- Department of Pharmaceutical Sciences, Mohanlal Sukhadia University, Udaipur, India
| | - Satyendra K Prasad
- Department of Pharmaceutical Sciences, Rashtrasant Tukadoji Maharaj Nagpur University, Nagpur, Maharashtra, India
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4
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Navarro-Garcia F. Serine proteases autotransporter of Enterobacteriaceae: Structures, subdomains, motifs, functions, and targets. Mol Microbiol 2023; 120:178-193. [PMID: 37392318 DOI: 10.1111/mmi.15116] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 06/12/2023] [Accepted: 06/13/2023] [Indexed: 07/03/2023]
Abstract
Serine protease autotransporters of Enterobacteriaceae (SPATE) constitute a superfamily of virulence factors, resembling the trypsin-like superfamily of serine proteases. SPATEs accomplish multiple functions associated to disease development of their hosts, which could be the consequence of SPATE cleavage of host cell components. SPATEs have been divided into class-1 and class-2 based on structural differences and biological effects, including similar substrate specificity, cytotoxic effects on cultured cells, and enterotoxin activity on intestinal tissues for class-1 SPATEs, whereas most class-2 SPATEs exhibit a lectin-like activity with a predilection to degrade a variety of mucins, including leukocyte surface O-glycoproteins and soluble host proteins, resulting in mucosal colonization and immune modulation. In this review, the structure of class-1 and class-2 are analyzed, making emphasis on their putative functional subdomains as well as a description of their function is provided, including prototypical mechanism of action.
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Affiliation(s)
- Fernando Navarro-Garcia
- Department of Cell Biology, Centro de Investigación y de Estudios Avanzados del IPN, Mexico, Mexico
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5
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Pokharel P, Dhakal S, Dozois CM. The Diversity of Escherichia coli Pathotypes and Vaccination Strategies against This Versatile Bacterial Pathogen. Microorganisms 2023; 11:344. [PMID: 36838308 PMCID: PMC9965155 DOI: 10.3390/microorganisms11020344] [Citation(s) in RCA: 27] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Revised: 01/24/2023] [Accepted: 01/25/2023] [Indexed: 02/03/2023] Open
Abstract
Escherichia coli (E. coli) is a gram-negative bacillus and resident of the normal intestinal microbiota. However, some E. coli strains can cause diseases in humans, other mammals and birds ranging from intestinal infections, for example, diarrhea and dysentery, to extraintestinal infections, such as urinary tract infections, respiratory tract infections, meningitis, and sepsis. In terms of morbidity and mortality, pathogenic E. coli has a great impact on public health, with an economic cost of several billion dollars annually worldwide. Antibiotics are not usually used as first-line treatment for diarrheal illness caused by E. coli and in the case of bloody diarrhea, antibiotics are avoided due to the increased risk of hemolytic uremic syndrome. On the other hand, extraintestinal infections are treated with various antibiotics depending on the site of infection and susceptibility testing. Several alarming papers concerning the rising antibiotic resistance rates in E. coli strains have been published. The silent pandemic of multidrug-resistant bacteria including pathogenic E. coli that have become more difficult to treat favored prophylactic approaches such as E. coli vaccines. This review provides an overview of the pathogenesis of different pathotypes of E. coli, the virulence factors involved and updates on the major aspects of vaccine development against different E. coli pathotypes.
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Affiliation(s)
- Pravil Pokharel
- Centre Armand-Frappier Santé Biotechnologie, Institut National de la Recherche Scientifique (INRS), 531 Boul des Prairies, Laval, QC H7V 1B7, Canada
- Centre de Recherche en Infectiologie Porcine et Avicole (CRIPA), Faculté de Médecine Vétérinaire, Université de Montréal Saint-Hyacinthe, Saint-Hyacinthe, QC J2S 2M2, Canada
| | - Sabin Dhakal
- Centre Armand-Frappier Santé Biotechnologie, Institut National de la Recherche Scientifique (INRS), 531 Boul des Prairies, Laval, QC H7V 1B7, Canada
- Centre de Recherche en Infectiologie Porcine et Avicole (CRIPA), Faculté de Médecine Vétérinaire, Université de Montréal Saint-Hyacinthe, Saint-Hyacinthe, QC J2S 2M2, Canada
| | - Charles M. Dozois
- Centre Armand-Frappier Santé Biotechnologie, Institut National de la Recherche Scientifique (INRS), 531 Boul des Prairies, Laval, QC H7V 1B7, Canada
- Centre de Recherche en Infectiologie Porcine et Avicole (CRIPA), Faculté de Médecine Vétérinaire, Université de Montréal Saint-Hyacinthe, Saint-Hyacinthe, QC J2S 2M2, Canada
- Pasteur Network, Laval, QC H7V 1B7, Canada
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6
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Alhammadi MM, Godfrey RE, Ingram JO, Singh G, Bathurst CL, Busby SJW, Browning DF. Novel organisation and regulation of the pic promoter from enteroaggregative and uropathogenic Escherichia coli. Virulence 2022; 13:1393-1406. [PMID: 35971774 PMCID: PMC9387333 DOI: 10.1080/21505594.2022.2111754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The serine protease autotransporters of the Enterobacteriaceae (SPATEs) are a large family of virulence factors commonly found in enteric bacteria. These secreted virulence factors have diverse functions during bacterial infection, including adhesion, aggregation and cell toxicity. One such SPATE, the Pic mucinase (protein involved in colonisation) cleaves mucin, allowing enteric bacterial cells to utilise mucin as a carbon source and to penetrate the gut mucus lining, thereby increasing mucosal colonisation. The pic gene is widely distributed within the Enterobacteriaceae, being found in human pathogens, such as enteroaggregative Escherichia coli (EAEC), uropathogenic E. coli (UPEC) and Shigella flexneri 2a. As the pic promoter regions from EAEC strain 042 and UPEC strain CFT073 differ, we have investigated the regulation of each promoter. Here, using in vivo and in vitro techniques, we show that both promoters are activated by the global transcription factor, CRP (cyclic AMP receptor protein), but the architectures of the EAEC and the UPEC pic promoter differ. Expression from both pic promoters is repressed by the nucleoid-associated factor, Fis, and maximal promoter activity occurs when cells are grown in minimal medium. As CRP activates transcription in conditions of nutrient depletion, whilst Fis levels are maximal in nutrient-rich environments, the regulation of the EAEC and UPEC pic promoters is consistent with Pic’s nutritional role in scavenging mucin as a suitable carbon source during colonisation and infection.
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Affiliation(s)
- Munirah M Alhammadi
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, UK.,Biology Department, Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia
| | - Rita E Godfrey
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, UK
| | - Joseph O Ingram
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, UK
| | - Gurdamanjit Singh
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, UK
| | - Camilla L Bathurst
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, UK
| | - Stephen J W Busby
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, UK
| | - Douglas F Browning
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, UK.,College of Health & Life Sciences, Aston University, Birmingham, UK
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7
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Schüroff PA, Salvador FA, Abe CM, Wami HT, Carvalho E, Hernandes RT, Dobrindt U, Gomes TAT, Elias WP. The aggregate-forming pili (AFP) mediates the aggregative adherence of a hybrid-pathogenic Escherichia coli (UPEC/EAEC) isolated from a urinary tract infection. Virulence 2021; 12:3073-3093. [PMID: 34923895 PMCID: PMC8923075 DOI: 10.1080/21505594.2021.2007645] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Enteroaggregative Escherichia coli (EAEC) comprises an important diarrheagenic pathotype, while uropathogenic E. coli (UPEC) is the most important agent of urinary tract infection (UTI). Recently, EAEC virulence factors have been detected in E. coli strains causing UTI, showing the importance of these hybrid-pathogenic strains. Previously, we detected an E. coli strain isolated from UTI (UPEC-46) presenting characteristics of EAEC, e.g., the aggregative adherence (AA) pattern and EAEC-associated genes (aatA, aap, and pet). In this current study, we analyzed the whole genomic sequence of UPEC-46 and characterized some phenotypic traits. The AA phenotype was observed in cell lineages of urinary and intestinal origin. The production of curli, cellulose, bacteriocins, and Pet toxin was detected. Additionally, UPEC-46 was not capable of forming biofilm using different culture media and human urine. The genome sequence analysis showed that this strain belongs to serotype O166:H12, ST10, and phylogroup A, harbors the tet, aadA, and dfrA/sul resistance genes, and is phylogenetically more related to EAEC strains isolated from human feces. UPEC-46 harbors three plasmids. Plasmid p46-1 (~135 kb) carries some EAEC marker genes and those encoding the aggregate-forming pili (AFP) and its regulator (afpR). A mutation in afpA (encoding the AFP major pilin) led to the loss of pilin production and assembly, and notably, a strongly reduced adhesion to epithelial cells. In summary, the genetic background and phenotypic traits analyzed suggest that UPEC-46 is a hybrid strain (UPEC/EAEC) and highlights the importance of AFP adhesin in the adherence to colorectal and bladder cell lines.
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Affiliation(s)
- Paulo A Schüroff
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, Brazil.,Institute of Hygiene, University of Münster, Münster, Germany
| | - Fábia A Salvador
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Cecilia M Abe
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, Brazil
| | - Haleluya T Wami
- Institute of Hygiene, University of Münster, Münster, Germany
| | - Eneas Carvalho
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, Brazil
| | - Rodrigo T Hernandes
- Instituto de Biociências, Universidade Estadual Paulista (UNESP), Botucatu, Brazil
| | - Ulrich Dobrindt
- Institute of Hygiene, University of Münster, Münster, Germany
| | - Tânia A T Gomes
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Waldir P Elias
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, Brazil
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8
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Prieto A, Bernabeu M, Sánchez-Herrero JF, Pérez-Bosque A, Miró L, Bäuerl C, Collado C, Hüttener M, Juárez A. Modulation of AggR levels reveals features of virulence regulation in enteroaggregative E. coli. Commun Biol 2021; 4:1295. [PMID: 34785760 PMCID: PMC8595720 DOI: 10.1038/s42003-021-02820-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 10/22/2021] [Indexed: 11/16/2022] Open
Abstract
Enteroaggregative Escherichia coli (EAEC) strains are one of the diarrheagenic pathotypes. EAEC strains harbor a virulence plasmid (pAA2) that encodes, among other virulence determinants, the aggR gene. The expression of the AggR protein leads to the expression of several virulence determinants in both plasmids and chromosomes. In this work, we describe a novel mechanism that influences AggR expression. Because of the absence of a Rho-independent terminator in the 3'UTR, aggR transcripts extend far beyond the aggR ORF. These transcripts are prone to PNPase-mediated degradation. Structural alterations in the 3'UTR result in increased aggR transcript stability, leading to increased AggR levels. We therefore investigated the effect of increased AggR levels on EAEC virulence. Upon finding the previously described AggR-dependent virulence factors, we detected novel AggR-regulated genes that may play relevant roles in EAEC virulence. Mutants exhibiting high AggR levels because of structural alterations in the aggR 3'UTR show increased mobility and increased pAA2 conjugation frequency. Furthermore, among the genes exhibiting increased fold change values, we could identify those of metabolic pathways that promote increased degradation of arginine, fatty acids and gamma-aminobutyric acid (GABA), respectively. In this paper, we discuss how the AggR-dependent increase in specific metabolic pathways activity may contribute to EAEC virulence.
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Affiliation(s)
- Alejandro Prieto
- Department of Genetics, Microbiology and Statistics, Universitat de Barcelona, Barcelona, Spain
| | - Manuel Bernabeu
- Department of Genetics, Microbiology and Statistics, Universitat de Barcelona, Barcelona, Spain
| | | | - Anna Pérez-Bosque
- Department of Biochemistry and Physiology, Universitat de Barcelona, Barcelona, Spain
- Institut de Nutrició i Seguretat Alimentària, Universitat de Barcelona, Barcelona, Spain
| | - Lluïsa Miró
- Department of Biochemistry and Physiology, Universitat de Barcelona, Barcelona, Spain
- Institut de Nutrició i Seguretat Alimentària, Universitat de Barcelona, Barcelona, Spain
| | - Christine Bäuerl
- Institute of Agrochemistry and Food Technology, National Research Council (IATA-CSIC), Paterna, Valencia, Spain
| | - Carmen Collado
- Institute of Agrochemistry and Food Technology, National Research Council (IATA-CSIC), Paterna, Valencia, Spain
| | - Mário Hüttener
- Department of Genetics, Microbiology and Statistics, Universitat de Barcelona, Barcelona, Spain.
| | - Antonio Juárez
- Department of Genetics, Microbiology and Statistics, Universitat de Barcelona, Barcelona, Spain.
- Institute for Bioengineering of Catalonia, The Barcelona Institute of Science and Technology, Barcelona, Spain.
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9
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Non-diarrheagenic and diarrheagenic E. coli carrying supplementary virulence genes (SVG) are associated with diarrhea in children from Mexico. Microb Pathog 2021; 157:104994. [PMID: 34044054 DOI: 10.1016/j.micpath.2021.104994] [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: 11/12/2020] [Revised: 05/18/2021] [Accepted: 05/19/2021] [Indexed: 11/24/2022]
Abstract
Escherichia coli strains, including diarrheagenic E. coli (DEC), are among the most important causes of childhood diarrhea in developing countries. Since these strains also colonize healthy children, additional factors leading to diarrhea remains to be discovered. We therefore conducted a comprehensive study to investigate if supplementary virulence genes (SVG) carried by DEC strains and non-DEC strains, contribute to diarrhea in Mexican children. E. coli strains were isolated from n = 317 children between 6 and 12 years, n = 114 with diarrhea and n = 203 asymptomatic children from Northwestern Mexico, PCR was used to identify SVG, then virulence score and cytotoxic assay in HT-29 cells were performed to evaluate virulence of E. coli strains. DEC prevalence was 18.6% and its presence was significantly associated with diarrhea cases. aEPEC, tEAEC, ETEC, DAEC, aEAEC, tEPEC, and EIEC pathotypes were identified. aEPEC strains were significantly associated with asymptomatic children, whereas ETEC was only identified in children with diarrhea. E. coli strains carrying colonization-related SVG and/or proteolysis-related SVG were significantly associated with diarrhea. DEC strains were associated to diarrhea if strains carried SVG ehaC, kps, nleB, and/or espC. Virulence score was significantly higher in E. coli from diarrhea cases than asymptomatic. In addition, DEC strains carrying SVG+ were more virulent, followed by non-DEC SVG+ strains, and correlated with the cytotoxicity assay. Nearly 50% of DEC strains were MDR, and ~10% were XDR. In conclusion the findings of this work provide evidence that the presence of E. coli strains (regardless if strains are DEC or non-DEC) with SVG were associated with diarrhea in Mexican children.
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10
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Chen X, Ding Y, Bamert RS, Le Brun AP, Duff AP, Wu CM, Hsu HY, Shiota T, Lithgow T, Shen HH. Substrate-dependent arrangements of the subunits of the BAM complex determined by neutron reflectometry. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2021; 1863:183587. [PMID: 33639106 DOI: 10.1016/j.bbamem.2021.183587] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 02/09/2021] [Accepted: 02/17/2021] [Indexed: 12/22/2022]
Abstract
In Gram-negative bacteria, the β-barrel assembly machinery (BAM) complex catalyses the assembly of β-barrel proteins into the outer membrane, and is composed of five subunits: BamA, BamB, BamC, BamD and BamE. Once assembled, - β-barrel proteins can be involved in various functions including uptake of nutrients, export of toxins and mediating host-pathogen interactions, but the precise mechanism by which these ubiquitous and often essential β-barrel proteins are assembled is yet to be established. In order to determine the relative positions of BAM subunits in the membrane environment we reconstituted each subunit into a biomimetic membrane, characterizing their interaction and structural changes by Quartz Crystal Microbalance with Dissipation monitoring (QCM-D) and neutron reflectometry. Our results suggested that the binding of BamE, or a BamDE dimer, to BamA induced conformational changes in the polypeptide transported-associated (POTRA) domains of BamA, but that BamB or BamD alone did not promote any such changes. As monitored by neutron reflectometry, addition of an unfolded substrate protein extended the length of POTRA domains further away from the membrane interface as part of the mechanism whereby the substrate protein was folded into the membrane.
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Affiliation(s)
- Xiaoyu Chen
- Department of Materials Science & Engineering, Monash University, Clayton, VIC 3800, Australia
| | - Yue Ding
- Department of Materials Science & Engineering, Monash University, Clayton, VIC 3800, Australia; Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC 3800, Australia
| | - Rebecca S Bamert
- Infection & Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, VIC 3800, Australia
| | - Anton P Le Brun
- Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organisation (ANSTO), New Illawarra Road, Lucas Heights, NSW 2234, Australia
| | - Anthony P Duff
- National Deuteration Facility, Australian Nuclear Science and Technology Organisation (ANSTO), New Illawarra Road, Lucas Heights, NSW 2234, Australia
| | - Chun-Ming Wu
- Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organisation (ANSTO), New Illawarra Road, Lucas Heights, NSW 2234, Australia; National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - Hsien-Yi Hsu
- School of Energy and Environment & Department of Materials Science and Engineering, City University of Hong Kong, Kowloon Tong, Hong Kong, PR China; Shenzhen Research Institute of City University of Hong Kong, Shenzhen 518057, PR China
| | - Takuya Shiota
- Institute for Tenure Track Promotion, Organization for Promotion of Career Management, University of Miyazaki, Miyazaki, Japan
| | - Trevor Lithgow
- Infection & Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, VIC 3800, Australia.
| | - Hsin-Hui Shen
- Department of Materials Science & Engineering, Monash University, Clayton, VIC 3800, Australia; Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC 3800, Australia.
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11
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García A, Fox JG. A One Health Perspective for Defining and Deciphering Escherichia coli Pathogenic Potential in Multiple Hosts. Comp Med 2021; 71:3-45. [PMID: 33419487 PMCID: PMC7898170 DOI: 10.30802/aalas-cm-20-000054] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 08/17/2020] [Accepted: 09/19/2020] [Indexed: 11/05/2022]
Abstract
E. coli is one of the most common species of bacteria colonizing humans and animals. The singularity of E. coli 's genus and species underestimates its multifaceted nature, which is represented by different strains, each with different combinations of distinct virulence factors. In fact, several E. coli pathotypes, or hybrid strains, may be associated with both subclinical infection and a range of clinical conditions, including enteric, urinary, and systemic infections. E. coli may also express DNA-damaging toxins that could impact cancer development. This review summarizes the different E. coli pathotypes in the context of their history, hosts, clinical signs, epidemiology, and control. The pathotypic characterization of E. coli in the context of disease in different animals, including humans, provides comparative and One Health perspectives that will guide future clinical and research investigations of E. coli infections.
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Key Words
- aa, aggregative adherence
- a/e, attaching and effacing
- aepec, atypical epec
- afa, afimbrial adhesin
- aida-i, adhesin involved in diffuse adherence
- aiec, adherent invasive e. coli
- apec, avian pathogenic e. coli
- atcc, american type culture collection
- bfp, bundle-forming pilus
- cd, crohn disease
- cdt, cytolethal distending toxin gene
- clb, colibactin
- cnf, cytotoxic necrotizing factor
- cs, coli surface (antigens)
- daec, diffusely adhering e. coli
- db, dutch belted
- eae, e. coli attaching and effacing gene
- eaec, enteroaggregative e. coli
- eaf, epec adherence factor (plasmid)
- eahec, entero-aggregative-hemorrhagic e. coli
- east-1, enteroaggregative e. coli heat-stable enterotoxin
- e. coli, escherichia coli
- ed, edema disease
- ehec, enterohemorrhagic e. coli
- eiec, enteroinvasive e. coli
- epec, enteropathogenic e. coli
- esbl, extended-spectrum β-lactamase
- esp, e. coli secreted protein
- etec, enterotoxigenic e. coli
- expec, extraintestinal pathogenic e. coli
- fyua, yersiniabactin receptor gene
- gi, gastrointestinal
- hly, hemolysin
- hus, hemolytic uremic syndrome
- ibd, inflammatory bowel disease
- la, localized adherence
- lee, locus of enterocyte effacement
- lpf, long polar fimbriae
- lt, heat-labile (enterotoxin)
- mlst, multilocus sequence typing
- ndm, new delhi metallo-β-lactamase
- nzw, new zealand white
- pap, pyelonephritis-associated pilus
- pks, polyketide synthase
- sfa, s fimbrial adhesin
- slt, shiga-like toxin
- st, heat-stable (enterotoxin)
- stec, stx-producing e. coli
- stx, shiga toxin
- tepec, typical epec
- upec, uropathogenic e. coli
- uti, urinary tract infection
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Affiliation(s)
- Alexis García
- Molecular Sciences Research Center, University of Puerto Rico, San Juan, Puerto Rico; Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, Massachusetts; Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, Massachusetts;,
| | - James G Fox
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, Massachusetts
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12
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Rajan A, Robertson MJ, Carter HE, Poole NM, Clark JR, Green SI, Criss ZK, Zhao B, Karandikar U, Xing Y, Margalef-Català M, Jain N, Wilson RL, Bai F, Hyser JM, Petrosino J, Shroyer NF, Blutt SE, Coarfa C, Song X, Prasad BVV, Amieva MR, Grande-Allen J, Estes MK, Okhuysen PC, Maresso AW. Enteroaggregative E. coli Adherence to Human Heparan Sulfate Proteoglycans Drives Segment and Host Specific Responses to Infection. PLoS Pathog 2020; 16:e1008851. [PMID: 32986782 PMCID: PMC7553275 DOI: 10.1371/journal.ppat.1008851] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 10/13/2020] [Accepted: 08/01/2020] [Indexed: 02/06/2023] Open
Abstract
Enteroaggregative Escherichia coli (EAEC) is a significant cause of acute and chronic diarrhea, foodborne outbreaks, infections of the immunocompromised, and growth stunting in children in developing nations. There is no vaccine and resistance to antibiotics is rising. Unlike related E. coli pathotypes that are often associated with acute bouts of infection, EAEC is associated with persistent diarrhea and subclinical long-term colonization. Several secreted virulence factors have been associated with EAEC pathogenesis and linked to disease in humans, less certain are the molecular drivers of adherence to the intestinal mucosa. We previously established human intestinal enteroids (HIEs) as a model system to study host-EAEC interactions and aggregative adherence fimbriae A (AafA) as a major driver of EAEC adherence to HIEs. Here, we report a large-scale assessment of the host response to EAEC adherence from all four segments of the intestine across at least three donor lines for five E. coli pathotypes. The data demonstrate that the host response in the duodenum is driven largely by the infecting pathotype, whereas the response in the colon diverges in a patient-specific manner. Major pathways altered in gene expression in each of the four enteroid segments differed dramatically, with responses observed for inflammation, apoptosis and an overwhelming response to different mucin genes. In particular, EAEC both associated with large mucus droplets and specific mucins at the epithelial surface, binding that was ameliorated when mucins were removed, a process dependent on AafA. Pan-screening for glycans for binding to purified AafA identified the human ligand as heparan sulfate proteoglycans (HSPGs). Removal of HSPG abrogated EAEC association with HIEs. These results may mean that the human intestine responds remarkably different to distinct pathobionts that is dependent on the both the individual and intestinal segment in question, and uncover a major role for surface heparan sulfate proteoglycans as tropism-driving factor in adherence and/or colonization.
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Affiliation(s)
- Anubama Rajan
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, United States of America
| | - Matthew J. Robertson
- Molecular and Cell Biology-Mol. Regulation, Baylor College of Medicine, Houston, TX, United States of America
| | - Hannah E. Carter
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, United States of America
| | - Nina M. Poole
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, United States of America
| | - Justin R. Clark
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, United States of America
| | - Sabrina I. Green
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, United States of America
| | - Zachary K. Criss
- Department of Medicine Section of Gastroenterology and Hepatology, Baylor College of Medicine, Houston, TX, United States of America
| | - Boyang Zhao
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, United States of America
| | - Umesh Karandikar
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, United States of America
| | - Yikun Xing
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, United States of America
| | - Mar Margalef-Català
- Department of Pediatrics, Division of Infectious Diseases, Stanford University, Stanford, CA, United States of America
| | - Nikhil Jain
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, United States of America
| | - Reid L. Wilson
- Department of Bioengineering, Rice University, Houston, TX, United States of America
| | - Fan Bai
- Department of Biochemistry, Emory Comprehensive Glycomics Core, Emory University School of Medicine, Atlanta, GA, United States of America
| | - Joseph M. Hyser
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, United States of America
| | - Joseph Petrosino
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, United States of America
| | - Noah F. Shroyer
- Department of Medicine Section of Gastroenterology and Hepatology, Baylor College of Medicine, Houston, TX, United States of America
| | - Sarah E. Blutt
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, United States of America
| | - Cristian Coarfa
- Molecular and Cell Biology-Mol. Regulation, Baylor College of Medicine, Houston, TX, United States of America
- Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, United States of America
| | - Xuezheng Song
- Department of Biochemistry, Emory Comprehensive Glycomics Core, Emory University School of Medicine, Atlanta, GA, United States of America
| | - BV Venkataram Prasad
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, United States of America
| | - Manuel R. Amieva
- Department of Pediatrics, Division of Infectious Diseases, Stanford University, Stanford, CA, United States of America
| | - Jane Grande-Allen
- Department of Bioengineering, Rice University, Houston, TX, United States of America
| | - Mary K. Estes
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, United States of America
| | - Pablo C. Okhuysen
- Department of Infectious Diseases, The University of Texas MD Anderson Cancer Center, Houston, TX, United States of America
| | - Anthony W. Maresso
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, United States of America
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13
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The Serine Protease Autotransporters TagB, TagC, and Sha from Extraintestinal Pathogenic Escherichia coli Are Internalized by Human Bladder Epithelial Cells and Cause Actin Cytoskeletal Disruption. Int J Mol Sci 2020; 21:ijms21093047. [PMID: 32357479 PMCID: PMC7246781 DOI: 10.3390/ijms21093047] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Revised: 04/10/2020] [Accepted: 04/23/2020] [Indexed: 12/20/2022] Open
Abstract
TagB, TagC (tandem autotransporter genes B and C), and Sha (Serine-protease hemagglutinin autotransporter) are recently described members of the SPATE (serine protease autotransporters of Enterobacteriaceae) family. These SPATEs can cause cytopathic effects on bladder cells and contribute to urinary tract infection in a mouse model. Bladder epithelial cells form an important barrier in the urinary tract. Some SPATEs produced by pathogenic E. coli are known to breach the bladder epithelium. The capacity of these newly described SPATEs to alter bladder epithelial cells and the role of the serine protease active site were investigated. All three SPATE proteins were internalized by bladder epithelial cells and altered the distribution of actin cytoskeleton. Sha and TagC were also shown to degrade mucin and gelatin respectively. Inactivation of the serine catalytic site in each of these SPATEs did not affect secretion of the SPATEs from bacterial cells, but abrogated entry into epithelial cells, cytotoxicity, and proteolytic activity. Thus, our results show that the serine catalytic triad of these proteins is required for internalization in host cells, actin disruption, and degradation of host substrates such as mucin and gelatin.
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14
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Habouria H, Pokharel P, Maris S, Garénaux A, Bessaiah H, Houle S, Veyrier FJ, Guyomard-Rabenirina S, Talarmin A, Dozois CM. Three new serine-protease autotransporters of Enterobacteriaceae (SPATEs) from extra-intestinal pathogenic Escherichia coli and combined role of SPATEs for cytotoxicity and colonization of the mouse kidney. Virulence 2020; 10:568-587. [PMID: 31198092 PMCID: PMC6592367 DOI: 10.1080/21505594.2019.1624102] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Serine protease autotransporters of Enterobacteriaceae (SPATEs) are secreted proteins that contribute to virulence and function as proteases, toxins, adhesins, and/or immunomodulators. An extra-intestinal pathogenic E. coli (ExPEC) O1:K1 strain, QT598, isolated from a turkey, was shown to contain vat, tsh, and three uncharacterized SPATE-encoding genes. Uncharacterized SPATEs: Sha (Serine-protease hemagglutinin autotransporter), TagB and TagC (tandem autotransporter genes B and C) were tested for activities including hemagglutination, autoaggregation, and cytotoxicity when expressed in E. coli K-12. Sha and TagB conferred autoaggregation and hemagglutination activities. TagB, TagC, and Sha all exhibited cytopathic effects on a bladder epithelial cell line. In QT598, tagB and tagC are tandemly encoded on a genomic island, and were present in 10% of UTI isolates and 4.7% of avian E. coli. Sha is encoded on a virulence plasmid and was present in 1% of UTI isolates and 20% of avian E. coli. To specifically examine the role of SPATEs for infection, the 5 SPATE genes were deleted from strain QT598 and tested for cytotoxicity. Loss of all five SPATEs abrogated the cytopathic effect on bladder epithelial cells, although derivatives producing any of the 5 SPATEs retained cytopathic activity. In mouse infections, sha gene-expression was up-regulated a mean of sixfold in the bladder compared to growth in vitro. Loss of either tagBC or sha did not reduce urinary tract colonization. Deletion of all 5 SPATEs, however, significantly reduced competitive colonization of the kidney supporting a cumulative role of SPATEs for QT598 in the mouse UTI model.
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Affiliation(s)
- Hajer Habouria
- a Institut national de recherche scientifique (INRS)-Institut Armand Frappier , Laval , Quebec , Canada.,b Centre de recherche en infectiologie porcine et avicole (CRIPA)
| | - Pravil Pokharel
- a Institut national de recherche scientifique (INRS)-Institut Armand Frappier , Laval , Quebec , Canada.,b Centre de recherche en infectiologie porcine et avicole (CRIPA)
| | - Segolène Maris
- a Institut national de recherche scientifique (INRS)-Institut Armand Frappier , Laval , Quebec , Canada.,b Centre de recherche en infectiologie porcine et avicole (CRIPA)
| | - Amélie Garénaux
- a Institut national de recherche scientifique (INRS)-Institut Armand Frappier , Laval , Quebec , Canada.,b Centre de recherche en infectiologie porcine et avicole (CRIPA)
| | - Hicham Bessaiah
- a Institut national de recherche scientifique (INRS)-Institut Armand Frappier , Laval , Quebec , Canada.,b Centre de recherche en infectiologie porcine et avicole (CRIPA)
| | - Sébastien Houle
- a Institut national de recherche scientifique (INRS)-Institut Armand Frappier , Laval , Quebec , Canada.,b Centre de recherche en infectiologie porcine et avicole (CRIPA)
| | - Frédéric J Veyrier
- a Institut national de recherche scientifique (INRS)-Institut Armand Frappier , Laval , Quebec , Canada.,c Institut Pasteur International Network
| | - Stéphanie Guyomard-Rabenirina
- c Institut Pasteur International Network.,d Unité Environnement Santé , Institut Pasteur de Guadeloupe , Les Abymes , Guadeloupe , France
| | - Antoine Talarmin
- c Institut Pasteur International Network.,d Unité Environnement Santé , Institut Pasteur de Guadeloupe , Les Abymes , Guadeloupe , France
| | - Charles M Dozois
- a Institut national de recherche scientifique (INRS)-Institut Armand Frappier , Laval , Quebec , Canada.,b Centre de recherche en infectiologie porcine et avicole (CRIPA).,c Institut Pasteur International Network
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15
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Vieira PCG, Espinoza-Culupú AO, Nepomuceno R, Alves MR, Lebrun I, Elias WP, Ruiz RC. Secreted autotransporter toxin (Sat) induces cell damage during enteroaggregative Escherichia coli infection. PLoS One 2020; 15:e0228959. [PMID: 32084148 PMCID: PMC7034920 DOI: 10.1371/journal.pone.0228959] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 01/27/2020] [Indexed: 12/30/2022] Open
Abstract
Secreted autotransporter toxin (Sat) is a 107-kDa serine protease autotransporter of Enterobacteriaceae (SPATE) presenting cytotoxic activity in renal and bladder cells. Further studies have detected the Sat-encoding gene (sat) in enteroaggregative Escherichia coli (EAEC) and in E. coli strains isolated from neonatal septicemia and meningitis. Here, we investigated the role of Sat as a cytotoxin of EAEC. Sat was purified from a strain of E. coli harboring sat (DEC/Sat+, O126:H2) and used to raise antibodies in rabbit. The presence of Sat was detected by ELISA in the supernatant of 93.7% of EAEC strains harboring sat and in none lacking the gene. The effect of Sat during infection was investigated in polarized Caco-2 cells infected with Sat-producing EAEC (CV323/77, O125ab:H21). This strain induced intense cell detachment, which was inhibited by PMSF or Sat antiserum. Also, sat transcription and Sat production were detected during infection. Here we demonstrate that Sat is internalized in polarized cells leading to F-actin disruption which preceded cell detachment. A comparative study of the toxin action in cell lines corresponding to the infection sites in which bacteria carrying the sat gene have been isolated was performed. Cells originating from the gastrointestinal tract (Caco-2), urinary (LLC-PK1) and endothelium (HUVEC) were incubated with purified Sat. The time required for observation of cell damage differed according to the cell line. HUVEC cells were more sensitive to Sat than cells derived from urinary and intestinal tracts. The intense activity of Sat on the endothelial cells suggests that Sat could also be a virulence factor for the bacteria in the bloodstream. In addition, this is the first work demonstrating that Sat induces cytotoxic effect during EAEC infection in vitro. The cell damage observed during infection indicates that Sat may be another toxin with cytotoxic role in the EAEC pathogenesis.
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Affiliation(s)
| | | | | | - Marina R. Alves
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, SP, Brazil
| | - Ivo Lebrun
- Laboratório de Bioquímica e Biofísica, Instituto Butantan, São Paulo, SP, Brazil
| | - Waldir P. Elias
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, SP, Brazil
| | - Rita C. Ruiz
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, SP, Brazil
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16
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Pokharel P, Habouria H, Bessaiah H, Dozois CM. Serine Protease Autotransporters of the Enterobacteriaceae (SPATEs): Out and About and Chopping It Up. Microorganisms 2019; 7:E594. [PMID: 31766493 PMCID: PMC6956023 DOI: 10.3390/microorganisms7120594] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 11/13/2019] [Indexed: 02/06/2023] Open
Abstract
Autotransporters are secreted proteins with multiple functions produced by a variety of Gram-negative bacteria. In Enterobacteriaceae, a subgroup of these autotransporters are the SPATEs (serine protease autotransporters of Enterobacteriaceae). SPATEs play a crucial role in survival and virulence of pathogens such as Escherichia coli and Shigella spp. and contribute to intestinal and extra-intestinal infections. These high molecular weight proteases are transported to the external milieu by the type Va secretion system and function as proteases with diverse substrate specificities and biological functions including adherence and cytotoxicity. Herein, we provide an overview of SPATEs and discuss recent findings on the biological roles of these secreted proteins, including proteolysis of substrates, adherence to cells, modulation of the immune response, and virulence in host models. In closing, we highlight recent insights into the regulation of expression of SPATEs that could be exploited to understand fundamental SPATE biology.
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Affiliation(s)
- Pravil Pokharel
- Institut National de Recherche Scientifique (INRS)-Centre Armand-Frappier Santé Biotechnologie, Laval, QC H7V 1B7, Canada; (P.P.); (H.H.); (H.B.)
- Centre de Recherche en Infectiologie Porcine et Avicole (CRIPA), Saint-Hyacinthe, QC J2S 2M2, Canada
| | - Hajer Habouria
- Institut National de Recherche Scientifique (INRS)-Centre Armand-Frappier Santé Biotechnologie, Laval, QC H7V 1B7, Canada; (P.P.); (H.H.); (H.B.)
- Centre de Recherche en Infectiologie Porcine et Avicole (CRIPA), Saint-Hyacinthe, QC J2S 2M2, Canada
| | - Hicham Bessaiah
- Institut National de Recherche Scientifique (INRS)-Centre Armand-Frappier Santé Biotechnologie, Laval, QC H7V 1B7, Canada; (P.P.); (H.H.); (H.B.)
- Centre de Recherche en Infectiologie Porcine et Avicole (CRIPA), Saint-Hyacinthe, QC J2S 2M2, Canada
| | - Charles M. Dozois
- Institut National de Recherche Scientifique (INRS)-Centre Armand-Frappier Santé Biotechnologie, Laval, QC H7V 1B7, Canada; (P.P.); (H.H.); (H.B.)
- Centre de Recherche en Infectiologie Porcine et Avicole (CRIPA), Saint-Hyacinthe, QC J2S 2M2, Canada
- Institut Pasteur International Network, Laval, QC H7V 1B7, Canada
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17
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Sanchez-Villamil JI, Navarro-Garcia F, Castillo-Romero A, Gutierrez-Gutierrez F, Tapia D, Tapia-Pastrana G. Curcumin Blocks Cytotoxicity of Enteroaggregative and Enteropathogenic Escherichia coli by Blocking Pet and EspC Proteolytic Release From Bacterial Outer Membrane. Front Cell Infect Microbiol 2019; 9:334. [PMID: 31681620 PMCID: PMC6798032 DOI: 10.3389/fcimb.2019.00334] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 09/11/2019] [Indexed: 01/14/2023] Open
Abstract
Pet and EspC are toxins secreted by enteroaggregative (EAEC) and enteropathogenic (EPEC) diarrheagenic Escherichia coli pathotypes, respectively. Both toxins are members of the Serine Protease Autotransporters of Enterobacteriaceae (SPATEs) family. Pet and EspC are important virulence factors that produce cytotoxic and enterotoxic effects on enterocytes. Here, we evaluated the effect of curcumin, a polyphenolic compound obtained from the rhizomes of Curcuma longa L. (Zingiberaceae) on the secretion and cytotoxic effects of Pet and EspC proteins. We found that curcumin prevents Pet and EspC secretion without affecting bacterial growth or the expression of pet and espC. Our results show that curcumin affects the release of these SPATEs from the translocation domain, thereby affecting the pathogenesis of EAEC and EPEC. Curcumin-treated EAEC and EPEC did not induce significant cell damage like the ability to disrupt the actin cytoskeleton, without affecting their characteristic adherence patterns on epithelial cells. A molecular model of docking predicted that curcumin interacts with the determinant residues Asp1018-Asp1019 and Asp1029-Asp1030 of the translocation domain required for the release of Pet and EspC, respectively. Consequently, curcumin blocks Pet and EspC cytotoxicity on epithelial cells by preventing their release from the outer membrane.
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Affiliation(s)
- Javier I Sanchez-Villamil
- Department of Cell Biology, Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV-IPN), Mexico City, Mexico
| | - Fernando Navarro-Garcia
- Department of Cell Biology, Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV-IPN), Mexico City, Mexico
| | - Araceli Castillo-Romero
- Department of Microbiology and Pathology, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara, Mexico
| | - Filiberto Gutierrez-Gutierrez
- Department of Chemistry, Centro Universitario de Ciencias Exactas e Ingenierías, Universidad de Guadalajara, Guadalajara, Mexico
| | - Daniel Tapia
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States
| | - Gabriela Tapia-Pastrana
- Laboratory of Biomedical Investigation, Hospital Regional de Alta Especialidad de Oaxaca, San Bartolo Coyotepec, Mexico
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18
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The Complete Genome of the Atypical Enteropathogenic Escherichia coli Archetype Isolate E110019 Highlights a Role for Plasmids in Dissemination of the Type III Secreted Effector EspT. Infect Immun 2019; 87:IAI.00412-19. [PMID: 31358567 DOI: 10.1128/iai.00412-19] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 07/18/2019] [Indexed: 12/21/2022] Open
Abstract
Enteropathogenic Escherichia coli (EPEC) is a leading cause of moderate to severe diarrhea among young children in developing countries, and EPEC isolates can be subdivided into two groups. Typical EPEC (tEPEC) bacteria are characterized by the presence of both the locus of enterocyte effacement (LEE) and the plasmid-encoded bundle-forming pilus (BFP), which are involved in adherence and translocation of type III effectors into the host cells. Atypical EPEC (aEPEC) bacteria also contain the LEE but lack the BFP. In the current report, we describe the complete genome of outbreak-associated aEPEC isolate E110019, which carries four plasmids. Comparative genomic analysis demonstrated that the type III secreted effector EspT gene, an autotransporter gene, a hemolysin gene, and putative fimbrial genes are all carried on plasmids. Further investigation of 65 espT-containing E. coli genomes demonstrated that different espT alleles are associated with multiple plasmids that differ in their overall gene content from the E110019 espT-containing plasmid. EspT has been previously described with respect to its role in the ability of E110019 to invade host cells. While other type III secreted effectors of E. coli have been identified on insertion elements and prophages of the chromosome, we demonstrated in the current study that the espT gene is located on multiple unique plasmids. These findings highlight a role of plasmids in dissemination of a unique E. coli type III secreted effector that is involved in host invasion and severe diarrheal illness.
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19
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Abstract
Plasmids have a major role in the development of disease caused by enteric bacterial pathogens. Virulence plasmids are usually large (>40 kb) low copy elements and encode genes that promote host-pathogen interactions. Although virulence plasmids provide advantages to bacteria in specific conditions, they often impose fitness costs on their host. In this Review, we discuss virulence plasmids in Enterobacteriaceae that are important causes of diarrhoea in humans, Shigella spp., Salmonella spp., Yersinia spp and pathovars of Escherichia coli. We contrast these plasmids with those that are routinely used in the laboratory and outline the mechanisms by which virulence plasmids are maintained in bacterial populations. We highlight examples of virulence plasmids that encode multiple mechanisms for their maintenance (for example, toxin-antitoxin and partitioning systems) and speculate on how these might contribute to their propagation and success.
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20
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Secreted proteases: A new insight in the pathogenesis of extraintestinal pathogenic Escherichia coli. Int J Med Microbiol 2019; 309:159-168. [DOI: 10.1016/j.ijmm.2019.03.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 02/19/2019] [Accepted: 03/04/2019] [Indexed: 11/20/2022] Open
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21
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Borgersen Q, Bolick DT, Kolling GL, Aijuka M, Ruiz-Perez F, Guerrant RL, Nataro JP, Santiago AE. Abundant production of exopolysaccharide by EAEC strains enhances the formation of bacterial biofilms in contaminated sprouts. Gut Microbes 2018; 9:264-278. [PMID: 29543544 PMCID: PMC6219584 DOI: 10.1080/19490976.2018.1429877] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 01/02/2018] [Accepted: 01/12/2018] [Indexed: 02/03/2023] Open
Abstract
Enteroaggregative E. coli (EAEC) is associated with food-borne outbreaks of diarrhea and growth faltering among children in developing countries. A Shiga toxin-producing EAEC strain of serotype O104:H4 strain caused one of the largest outbreaks of a food-borne infection in Europe in 2011. The outbreak was traced to contaminated fenugreek sprouts, yet the mechanisms whereby such persistent contamination of sprouts could have occurred are not clear. We found that under ambient conditions of temperature and in minimal media, pathogenic Shiga toxin-producing EAEC O104:H4 227-11 and non-Shiga toxin-producing 042 strains both produce high levels of exopolysaccharide structures (EPS) that are released to the external milieu. The exopolysaccharide was identified as colanic acid (CA). Unexpectedly, Shiga-toxin producing EAEC strain 227-11 produced 3-6-fold higher levels of CA than the 042 strain, suggesting differential regulation of the CA in the two strains. The presence of CA was accompanied by the formation of large biofilm structures on the surface of sprouts. The wcaF-wza chromosomal locus was required for the synthesis of CA in EAEC 042. Deletion in the glycosyltransferase wcaE gene abolished the production of CA in 042, and resulted in diminished adherence to sprouts when co-cultured at ambient temperature. In conclusion, this work suggests that copious production of CA may contribute to persistence of EAEC in the environment and suggests a potential explanation for the large Shiga toxin-producing EAEC outbreak in 2011.
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Affiliation(s)
- Quintin Borgersen
- Department of Pediatrics, University of Virginia School of Medicine and University of Virginia Children's Hospital, Charlottesville, Virginia
| | - David T. Bolick
- Center for Global Health, Division of Infectious Diseases and International Health, Department of Medicine, University of Virginia, Charlottesville, VA , USA
| | - Glynis L. Kolling
- Center for Global Health, Division of Infectious Diseases and International Health, Department of Medicine, University of Virginia, Charlottesville, VA , USA
| | - Matthew Aijuka
- Department of Pediatrics, University of Virginia School of Medicine and University of Virginia Children's Hospital, Charlottesville, Virginia
| | - Fernando Ruiz-Perez
- Department of Pediatrics, University of Virginia School of Medicine and University of Virginia Children's Hospital, Charlottesville, Virginia
| | - Richard L. Guerrant
- Center for Global Health, Division of Infectious Diseases and International Health, Department of Medicine, University of Virginia, Charlottesville, VA , USA
| | - James P. Nataro
- Department of Pediatrics, University of Virginia School of Medicine and University of Virginia Children's Hospital, Charlottesville, Virginia
| | - Araceli E. Santiago
- Department of Pediatrics, University of Virginia School of Medicine and University of Virginia Children's Hospital, Charlottesville, Virginia
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22
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Molecular basis for the folding of β-helical autotransporter passenger domains. Nat Commun 2018; 9:1395. [PMID: 29643377 PMCID: PMC5895577 DOI: 10.1038/s41467-018-03593-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 02/27/2018] [Indexed: 11/23/2022] Open
Abstract
Bacterial autotransporters comprise a C-terminal β-barrel domain, which must be correctly folded and inserted into the outer membrane to facilitate translocation of the N-terminal passenger domain to the cell exterior. Once at the surface, the passenger domains of most autotransporters are folded into an elongated β-helix. In a cellular context, key molecules catalyze the assembly of the autotransporter β-barrel domain. However, how the passenger domain folds into its functional form is poorly understood. Here we use mutational analysis on the autotransporter Pet to show that the β-hairpin structure of the fifth extracellular loop of the β-barrel domain has a crucial role for passenger domain folding into a β-helix. Bioinformatics and structural analyses, and mutagenesis of a homologous autotransporter, suggest that this function is conserved among autotransporter proteins with β-helical passenger domains. We propose that the autotransporter β-barrel domain is a folding vector that nucleates folding of the passenger domain. Autotransporter passenger domains are presented on or released from the bacterial surface upon translocation through an outer membrane β-barrel anchor. Here the authors study the two E. coli autotransporters Pet and EspP and propose that the β-barrel anchor acts as a vector to nucleate the folding of the passenger domain.
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23
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Affiliation(s)
- Bente Olesen
- Department of Clinical Microbiology, Herlev and Gentofte Hospital, University of Copenhagen, Denmark
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24
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Ikumapayi UN, Boisen N, Hossain MJ, Betts M, Lamin M, Saha D, Kwambana-Adams B, Dione M, Adegbola RA, Roca A, Nataro JP, Antonio M. Identification of Subsets of Enteroaggregative Escherichia coli Associated with Diarrheal Disease among Under 5 Years of Age Children from Rural Gambia. Am J Trop Med Hyg 2017; 97:997-1004. [PMID: 28820687 PMCID: PMC5637583 DOI: 10.4269/ajtmh.16-0705] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Enteroaggregative Escherichia coli (EAEC) cause acute and persistent diarrhea, mostly in children worldwide. Outbreaks of diarrhea caused by EAEC have been described, including a large outbreak caused by a Shiga toxin expressing strain. This study investigated the association of EAEC virulence factors with diarrhea in children less than 5 years. We characterized 428 EAEC strains isolated from stool samples obtained from moderate-to-severe diarrhea cases (157) and healthy controls (217) children aged 0–59 months recruited over 3 years as part of the Global Enteric Multicenter Study (GEMS) in The Gambia. Four sets of multiplex polymerase chain reaction were applied to detect 21 EAEC-virulence genes from confirmed EAEC strains that target pCVD432 (aatA) and AAIC (aaiC). In addition, Kirby-Bauer disc diffusion antimicrobial susceptibility testing was performed on 88 EAEC strains following Clinical Laboratory Standard Institute guidelines. We observed that the plasmid-encoded enterotoxin [odds ratio (OR): 6.9, 95% confidence interval (CI): 2.06–29.20, P < 0.001], aggregative adherence fimbriae/I fimbriae (aggA) [OR: 2.2, 95% CI: 1.16–4.29, P = 0.008], and hexosyltransferase (capU) [OR: 1.9, 95% CI 1.02–3.51, P = 0.028] were associated with moderate-to-severe diarrhea among children < 12 months old but not in the older age strata (> 12 months). Our data suggest that some EAEC-virulent factors have age-specific associations with moderate-to-severe diarrhea in infants. Furthermore, our study showed that 85% and 72% of EAEC strains tested were resistant to sulphamethoxazole-trimethoprim and ampicillin, respectively. Sulphamethoxazole-trimethoprim and ampicillin are among the first-line antibiotics used for the treatment of diarrhea in The Gambia.
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Affiliation(s)
- Usman N Ikumapayi
- Disease Control and Elimination Theme, Medical Research Council Unit The Gambia, Banjul, The Gambia.,Vaccines and Immunity Theme, Medical Research Council Unit The Gambia, Banjul, The Gambia
| | - Nadia Boisen
- Department of Microbiological Surveillance and Research, Statens Serum Institut, Copenhagen, Denmark
| | - Mohammad J Hossain
- Disease Control and Elimination Theme, Medical Research Council Unit The Gambia, Banjul, The Gambia
| | - Modupeh Betts
- Vaccines and Immunity Theme, Medical Research Council Unit The Gambia, Banjul, The Gambia
| | - Modou Lamin
- Disease Control and Elimination Theme, Medical Research Council Unit The Gambia, Banjul, The Gambia
| | - Debasish Saha
- Vaccines and Immunity Theme, Medical Research Council Unit The Gambia, Banjul, The Gambia
| | - Brenda Kwambana-Adams
- Vaccines and Immunity Theme, Medical Research Council Unit The Gambia, Banjul, The Gambia
| | - Michel Dione
- Vaccines and Immunity Theme, Medical Research Council Unit The Gambia, Banjul, The Gambia
| | - Richard A Adegbola
- Vaccines and Immunity Theme, Medical Research Council Unit The Gambia, Banjul, The Gambia
| | - Anna Roca
- Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom.,Disease Control and Elimination Theme, Medical Research Council Unit The Gambia, Banjul, The Gambia
| | - James P Nataro
- Department of Pediatrics, University of Virginia School of Medicine, Charlottesville, Virginia.,Centre for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland
| | - Martin Antonio
- Microbiology and Infection Unit, Warwick Medical School, University of Warwick, Coventry, United Kingdom.,Vaccines and Immunity Theme, Medical Research Council Unit The Gambia, Banjul, The Gambia.,Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
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25
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Andrade FB, Abreu AG, Nunes KO, Gomes TA, Piazza RM, Elias WP. Distribution of serine protease autotransporters of Enterobacteriaceae in typical and atypical enteroaggregative Escherichia coli. INFECTION GENETICS AND EVOLUTION 2017; 50:83-86. [DOI: 10.1016/j.meegid.2017.02.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 02/23/2017] [Accepted: 02/25/2017] [Indexed: 10/20/2022]
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26
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Hebbelstrup Jensen B, Poulsen A, Hebbelstrup Rye Rasmussen S, Struve C, Engberg JH, Friis-Møller A, Boisen N, Jønsson R, Petersen RF, Petersen AM, Krogfelt KA. Genetic Virulence Profile of Enteroaggregative Escherichia coli Strains Isolated from Danish Children with Either Acute or Persistent Diarrhea. Front Cell Infect Microbiol 2017; 7:230. [PMID: 28611957 PMCID: PMC5447714 DOI: 10.3389/fcimb.2017.00230] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2017] [Accepted: 05/17/2017] [Indexed: 11/13/2022] Open
Abstract
Enteroaggregative Escherichia coli (EAEC) is frequently found in diarrheal stools worldwide. It has been associated with persistent diarrhea, weight loss, and failure to thrive in children living in developing countries. A number of important EAEC virulence genes are identified; however, their roles in acute and persistent diarrhea have not been previously investigated. The aim of this study was to identify specific EAEC virulence genes associated with duration and type of diarrhea in Danish children. We aimed to improve the current diagnostics of EAEC and enable targeting of strains with an expected severe disease course. Questionnaires answered by parents provided information regarding duration of diarrhea and presence of blood or mucus. A total of 295 EAEC strains were collected from children with acute (≤7 days) and persistent diarrhea (≥14 days) and were compared by using multiplex PCR targeting the genes sat, sepA, pic, sigA, pet, astA, aatA, aggR, aaiC, aap, agg3/4C, ORF3, aafA, aggA, agg3A, agg4A, and agg5A. Furthermore, the distribution of EAEC genes in strains collected from cases of bloody, mucoid, and watery diarrhea was investigated. The classification and regression tree analysis (CART) was applied to investigate the relationship between EAEC virulence genes and diarrheal duration and type. Persistent diarrhea was associated with strains lacking the pic gene (p = 0.002) and with the combination of the genes pic, sat, and absence of the aggA gene (p = 0.05). Prolonged diarrhea was associated with the combination of the genes aatA and astA (p = 0.03). Non-mucoid diarrhea was associated with strains lacking the aatA gene (p = 0.004). Acute diarrhea was associated with the genes aggR, aap, and aggA by individual odds ratios. Resistance toward gentamicin and ciprofloxacin was observed in 7.5 and 3% of strains, respectively. Multi-drug resistance was observed in 38% of strains. Genetic host factors have been associated with an increased risk of EAEC-associated disease. Therefore, we investigated a panel of risk factors in two groups of children—EAEC-positive and EAEC-negative—to identify additional factors predisposing to disease. The duration of breastfeeding was positively correlated with the likelihood of belonging to the EAEC-negative group of children.
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Affiliation(s)
| | - Anja Poulsen
- Department of Gastroenterology, Copenhagen University Hospital HvidovreCopenhagen, Denmark
| | | | - Carsten Struve
- Department of Bacteria, Parasites and Fungi, Statens Serum InstitutCopenhagen, Denmark
| | - Jørgen H Engberg
- Department of Clinical Microbiology, Slagelse HospitalSlagelse, Denmark
| | - Alice Friis-Møller
- Department of Clinical Microbiology, Copenhagen University Hospital HvidovreCopenhagen, Denmark
| | - Nadia Boisen
- Department of Bacteria, Parasites and Fungi, Statens Serum InstitutCopenhagen, Denmark
| | - Rie Jønsson
- Department of Bacteria, Parasites and Fungi, Statens Serum InstitutCopenhagen, Denmark
| | - Randi F Petersen
- Department of Bacteria, Parasites and Fungi, Statens Serum InstitutCopenhagen, Denmark
| | - Andreas M Petersen
- Department of Bacteria, Parasites and Fungi, Statens Serum InstitutCopenhagen, Denmark.,Department of Gastroenterology, Copenhagen University Hospital HvidovreCopenhagen, Denmark.,Department of Clinical Microbiology, Copenhagen University Hospital HvidovreCopenhagen, Denmark
| | - Karen A Krogfelt
- Department of Bacteria, Parasites and Fungi, Statens Serum InstitutCopenhagen, Denmark
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27
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Jønsson R, Struve C, Boll EJ, Boisen N, Joensen KG, Sørensen CA, Jensen BH, Scheutz F, Jenssen H, Krogfelt KA. A Novel pAA Virulence Plasmid Encoding Toxins and Two Distinct Variants of the Fimbriae of Enteroaggregative Escherichia coli. Front Microbiol 2017; 8:263. [PMID: 28275371 PMCID: PMC5320562 DOI: 10.3389/fmicb.2017.00263] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 02/07/2017] [Indexed: 11/29/2022] Open
Abstract
Enteroaggregative Escherichia coli (EAEC) is an increasingly recognized pathogen associated with acute and persistent diarrhea worldwide. While EAEC strains are considered highly heterogeneous, aggregative adherence fimbriae (AAFs) are thought to play a pivotal role in pathogenicity by facilitating adherence to the intestinal mucosa. In this study, we optimized an existing multiplex PCR to target all known AAF variants, which are distinguished by differences in their pilin subunits. We applied the assay on a collection of 162 clinical Danish EAEC strains and interestingly found six, by SNP analysis phylogenetically distinct, strains harboring the major pilin subunits from both AAF/III and AAF/V. Whole-genome and plasmid sequencing revealed that in these six strains the agg3A and agg5A genes were located on a novel pAA plasmid variant. Moreover, the plasmid also encoded several other virulence genes including some not previously found on pAA plasmids. Thus, this plasmid endows the host strains with a remarkably high number of EAEC associated virulence genes hereby likely promoting strain pathogenicity.
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Affiliation(s)
- Rie Jønsson
- Department of Science and Environment, Roskilde UniversityRoskilde, Denmark; Department of Microbiology and Infection Control, Statens Serum InstitutCopenhagen, Denmark
| | - Carsten Struve
- Department of Microbiology and Infection Control, Statens Serum Institut Copenhagen, Denmark
| | - Erik J Boll
- Department of Microbiology and Infection Control, Statens Serum Institut Copenhagen, Denmark
| | - Nadia Boisen
- Department of Microbiology and Infection Control, Statens Serum Institut Copenhagen, Denmark
| | - Katrine G Joensen
- Department of Microbiology and Infection Control, Statens Serum Institut Copenhagen, Denmark
| | - Camilla A Sørensen
- Department of Microbiology and Infection Control, Statens Serum Institut Copenhagen, Denmark
| | - Betina H Jensen
- Department of Microbiology and Infection Control, Statens Serum Institut Copenhagen, Denmark
| | - Flemming Scheutz
- Department of Microbiology and Infection Control, Statens Serum Institut Copenhagen, Denmark
| | - Håvard Jenssen
- Department of Science and Environment, Roskilde University Roskilde, Denmark
| | - Karen A Krogfelt
- Department of Microbiology and Infection Control, Statens Serum Institut Copenhagen, Denmark
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28
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Walsh SI, Craney A, Romesberg FE. Not just an antibiotic target: Exploring the role of type I signal peptidase in bacterial virulence. Bioorg Med Chem 2016; 24:6370-6378. [PMID: 27769673 PMCID: PMC5279723 DOI: 10.1016/j.bmc.2016.09.048] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 09/17/2016] [Accepted: 09/19/2016] [Indexed: 01/23/2023]
Abstract
The looming antibiotic crisis has prompted the development of new strategies towards fighting infection. Traditional antibiotics target bacterial processes essential for viability, whereas proposed antivirulence approaches rely on the inhibition of factors that are required only for the initiation and propagation of infection within a host. Although antivirulence compounds have yet to prove their efficacy in the clinic, bacterial signal peptidase I (SPase) represents an attractive target in that SPase inhibitors exhibit broad-spectrum antibiotic activity, but even at sub-MIC doses also impair the secretion of essential virulence factors. The potential consequences of SPase inhibition on bacterial virulence have not been thoroughly examined, and are explored within this review. In addition, we review growing evidence that SPase has relevant biological functions outside of mediating secretion, and discuss how the inhibition of these functions may be clinically significant.
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Affiliation(s)
- Shawn I Walsh
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Arryn Craney
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Floyd E Romesberg
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
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29
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Gomes TAT, Elias WP, Scaletsky ICA, Guth BEC, Rodrigues JF, Piazza RMF, Ferreira LCS, Martinez MB. Diarrheagenic Escherichia coli. Braz J Microbiol 2016; 47 Suppl 1:3-30. [PMID: 27866935 PMCID: PMC5156508 DOI: 10.1016/j.bjm.2016.10.015] [Citation(s) in RCA: 247] [Impact Index Per Article: 30.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2016] [Accepted: 10/27/2016] [Indexed: 12/22/2022] Open
Abstract
Most Escherichia coli strains live harmlessly in the intestines and rarely cause disease in healthy individuals. Nonetheless, a number of pathogenic strains can cause diarrhea or extraintestinal diseases both in healthy and immunocompromised individuals. Diarrheal illnesses are a severe public health problem and a major cause of morbidity and mortality in infants and young children, especially in developing countries. E. coli strains that cause diarrhea have evolved by acquiring, through horizontal gene transfer, a particular set of characteristics that have successfully persisted in the host. According to the group of virulence determinants acquired, specific combinations were formed determining the currently known E. coli pathotypes, which are collectively known as diarrheagenic E. coli. In this review, we have gathered information on current definitions, serotypes, lineages, virulence mechanisms, epidemiology, and diagnosis of the major diarrheagenic E. coli pathotypes.
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Affiliation(s)
- Tânia A T Gomes
- Universidade Federal de São Paulo, Escola Paulista de Medicina, Departamento de Microbiologia, Imunologia e Parasitologia, São Paulo, SP, Brazil.
| | - Waldir P Elias
- Instituto Butantan, Laboratório de Bacterologia, São Paulo, SP, Brazil
| | - Isabel C A Scaletsky
- Universidade Federal de São Paulo, Escola Paulista de Medicina, Departamento de Microbiologia, Imunologia e Parasitologia, São Paulo, SP, Brazil
| | - Beatriz E C Guth
- Universidade Federal de São Paulo, Escola Paulista de Medicina, Departamento de Microbiologia, Imunologia e Parasitologia, São Paulo, SP, Brazil
| | - Juliana F Rodrigues
- Universidade de São Paulo, Instituto de Ciências Biomédicas, Departamento de Microbiologia, São Paulo, SP, Brazil
| | - Roxane M F Piazza
- Instituto Butantan, Laboratório de Bacterologia, São Paulo, SP, Brazil
| | - Luís C S Ferreira
- Universidade de São Paulo, Instituto de Ciências Biomédicas, Departamento de Microbiologia, São Paulo, SP, Brazil
| | - Marina B Martinez
- Universidade de São Paulo, Faculdade de Ciências Farmacêuticas, Departamento de Análises Clínicas e Toxicológicas, São Paulo, SP, Brazil
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30
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Imuta N, Ooka T, Seto K, Kawahara R, Koriyama T, Kojyo T, Iguchi A, Tokuda K, Kawamura H, Yoshiie K, Ogura Y, Hayashi T, Nishi J. Phylogenetic Analysis of Enteroaggregative Escherichia coli (EAEC) Isolates from Japan Reveals Emergence of CTX-M-14-Producing EAEC O25:H4 Clones Related to Sequence Type 131. J Clin Microbiol 2016; 54:2128-34. [PMID: 27252465 PMCID: PMC4963495 DOI: 10.1128/jcm.00711-16] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 05/27/2016] [Indexed: 12/11/2022] Open
Abstract
Enteroaggregative Escherichia coli (EAEC) causes acute or persistent diarrhea. The aggR gene is widely used as a marker for typical EAEC. The heterogeneity of EAEC is well known; however, there are few reports on the phylogenetic relationships of EAEC. Recently, CTX-M extended-spectrum β-lactamase (ESBL)-producing EAEC strains have been reported worldwide. To characterize EAEC strains in Japan, we investigated the population structure of EAEC. A total of 167 aggR-positive strains isolated from stool specimens from diarrheal patients in Kagoshima (139 strains) and Osaka (28 strains), Japan, between 1992 and 2010 were examined for the prevalence of EAEC virulence markers, the blaCTX-M gene, and the capacity to form biofilms. Multilocus sequence typing was also conducted. EAEC strains were widely distributed across four major E. coli phylogroups. Strains of O111:H21/clonal group 40 (CG40) (30 strains), O126:H27/CG200 (13 strains), and O86a:H27/CG3570 (11 strains) in phylogroup B1 are the historical EAEC clones in Japan, and they exhibited strong biofilm formation. Twenty-nine strains of EAEC O25:H4/CG131 were identified in phylogroup B2, 79% of which produced CTX-M-14. This clone has emerged since 2003. The clone harbored plasmid-encoded EAEC virulence genes but not chromosomal virulence genes and had lower biofilm-forming capacity than historical EAEC strains. This clone most likely emerged from a pandemic uropathogenic O25:H4/sequence type 131 clone by acquiring an EAEC virulence plasmid from canonical EAEC. Surveillance of the horizontal transfer of both virulence and ESBL genes among E. coli strains is important for preventing a worldwide increase in antimicrobial drug resistance.
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Affiliation(s)
- Naoko Imuta
- Department of Microbiology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Tadasuke Ooka
- Department of Microbiology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Kazuko Seto
- Osaka Prefectural Institute of Public Health, Osaka, Japan
| | - Ryuji Kawahara
- Osaka Prefectural Institute of Public Health, Osaka, Japan
| | - Toyoyasu Koriyama
- Clinical Laboratory, Kagoshima University Hospital, Kagoshima, Japan
| | - Tsuyoshi Kojyo
- Clinical Laboratory, Kagoshima University Hospital, Kagoshima, Japan
| | - Atsushi Iguchi
- Department of Animal and Grassland Sciences, Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan
| | - Koichi Tokuda
- Department of Infection Control and Prevention, Division of Medical and Environmental Safety, Kagoshima University Hospital, Kagoshima, Japan
| | - Hideki Kawamura
- Department of Infection Control and Prevention, Division of Medical and Environmental Safety, Kagoshima University Hospital, Kagoshima, Japan
| | - Kiyotaka Yoshiie
- Department of Microbiology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Yoshitoshi Ogura
- Department of Microbiology, Faculty of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Tetsuya Hayashi
- Department of Microbiology, Faculty of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Junichiro Nishi
- Department of Microbiology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan Department of Infection Control and Prevention, Division of Medical and Environmental Safety, Kagoshima University Hospital, Kagoshima, Japan
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31
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Rocha-Ramírez LM, Hernández-Chiñas U, Baños-Rojas D, Xicohtencatl-Cortés J, Chávez-Berrocal ME, Rico-Rosillo G, Kretschmer R, Eslava CA. Pet serine protease from enteroaggregative Escherichia coli stimulates the inflammatory response activating human macrophages. BMC Microbiol 2016; 16:158. [PMID: 27439312 PMCID: PMC4955197 DOI: 10.1186/s12866-016-0775-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 07/12/2016] [Indexed: 01/09/2023] Open
Abstract
Background Pet is a toxin from the family of Serine Protease Autotransporters of Enterobacteriaceae which was initially identified in Enteroaggregative Escherichia coli strains. This protease exhibits enterotoxin properties, damages the cell cytoskeleton and induces intestinal epithelium alterations, which are associated with a severe inflammatory process. An in-vitro study was conducted to evaluate the effect of Pet on the migration of human peripheral blood monocytes-derived macrophages and its participation in the activation of the early inflammatory response and cytokine expression. Results In the macrophage migration activation assay, Pet produced a similar effect to that induced by opsonized zymosan (ZAS). Regarding the cytokine expression, an increase of IL-8, TNF-α (pro-inflammatory) and IL-10 (anti-inflammatory) was identified. In addition to the above results, the nuclear translocation of NF-kB pp65 was also identified. These events are probably related to the inflammatory response identified in the histological examination of intestine rat samples inoculated with Pet during a ligated loop assay. Conclusion The results showed that Pet participates as an immunostimulant molecule for macrophages, which activates both their mobility and cytokine expression. These observations suggest that the toxin participates in the inflammatory process that is observed during the host infection by EAEC Pet producing.
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Affiliation(s)
- L M Rocha-Ramírez
- Departamento de Infectología, Hospital Infantil de México Federico Gómez, Dr. Márquez No. 162, Col Doctores, Delegación Cuauhtémoc, 06720, C. de México.
| | - U Hernández-Chiñas
- Departamento de Salud Pública, Facultad de Medicina, Universidad Nacional Autónoma de México, Circuito Escolar S/N, Ciudad Universitaria, Coyoacán, 04510, C. de México.,Laboratorio de Patogenicidad Bacteriana, Unidad de Hemato-Oncología e Investigación, Hospital Infantil de México Federico Gómez/Facultad de Medicina UNAM, Dr. Márquez No. 162, Col Doctores, Delegación Cuauhtémoc, 06720, C. de México
| | - D Baños-Rojas
- Departamento de Infectología, Hospital Infantil de México Federico Gómez, Dr. Márquez No. 162, Col Doctores, Delegación Cuauhtémoc, 06720, C. de México
| | - J Xicohtencatl-Cortés
- Laboratorio de Bacteriología Intestinal, Unidad de Hemato-Oncología e Investigación, Hospital Infantil de México Federico Gómez, Dr. Márquez No. 162, Col Doctores, Delegación Cuauhtémoc, 06720, C. de México
| | - M E Chávez-Berrocal
- Departamento de Salud Pública, Facultad de Medicina, Universidad Nacional Autónoma de México, Circuito Escolar S/N, Ciudad Universitaria, Coyoacán, 04510, C. de México.,Laboratorio de Patogenicidad Bacteriana, Unidad de Hemato-Oncología e Investigación, Hospital Infantil de México Federico Gómez/Facultad de Medicina UNAM, Dr. Márquez No. 162, Col Doctores, Delegación Cuauhtémoc, 06720, C. de México
| | - G Rico-Rosillo
- Divisiòn de Investigación. Facultad de Medicina, UNAM. Circuito Escolar S/N, Ciudad Universitaria, Coyoacán, 04510, C. de México
| | - R Kretschmer
- Unidad de Investigación Médica en Inmunología, Hospital de Pediatría, CMN siglo XXI, IMSS, Av. Cuauhtémoc No. 330, Col Doctores, Delegación Cuauhtémoc, 06720, C. de México
| | - C A Eslava
- Departamento de Salud Pública, Facultad de Medicina, Universidad Nacional Autónoma de México, Circuito Escolar S/N, Ciudad Universitaria, Coyoacán, 04510, C. de México. .,Laboratorio de Patogenicidad Bacteriana, Unidad de Hemato-Oncología e Investigación, Hospital Infantil de México Federico Gómez/Facultad de Medicina UNAM, Dr. Márquez No. 162, Col Doctores, Delegación Cuauhtémoc, 06720, C. de México.
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32
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Subdomain 2 of the Autotransporter Pet Is the Ligand Site for Recognizing the Pet Receptor on the Epithelial Cell Surface. Infect Immun 2016; 84:2012-2021. [PMID: 27113356 DOI: 10.1128/iai.01528-15] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 04/15/2016] [Indexed: 02/02/2023] Open
Abstract
Most autotransporter passenger domains, regardless of their diversity in function, fold or are predicted to fold as right-handed β-helices carrying various loops that are presumed to confer functionality. Our goal here was to identify the subdomain (loop) or amino acid sequence of the Pet passenger domain involved in the receptor binding site on the host cell for Pet endocytosis. Here, we show that d1 and d2 subdomains, as well as the amino acid sequence linking the subdomain d2 and the adjacent β-helix (PDWET), are not required for Pet secretion through the autotransporter system and that none of our deletion mutants altered the predicted long right-handed β-helical structure. Interestingly, Pet lacking the d2 domain (PetΔd2) was unable to bind on the epithelial cell surface, in contrast to Pet lacking d1 (PetΔd1) subdomain or PDWET sequences. Moreover, the purified d1 subdomain, the biggest subdomain (29.8 kDa) containing the serine protease domain, was also unable to bind the cell surface. Thus, d2 sequence (54 residues without the PDWET sequence) was required for Pet binding to eukaryotic cells. In addition, this d2 sequence was also needed for Pet internalization but not for inducing cell damage. In contrast, PetΔd1, which was able to bind and internalize inside the cell, was unable to cause cell damage. Furthermore, unlike Pet, PetΔd2 was unable to bind cytokeratin 8, a Pet receptor. These data indicate that the surface d2 subdomain is essential for the ligand-receptor (Pet-Ck8) interaction for Pet uptake and to start the epithelial cell damage by this toxin.
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33
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Durand D, Contreras CA, Mosquito S, Ruíz J, Cleary TG, Ochoa TJ. pic gene of enteroaggregative Escherichia coli and its association with diarrhea in Peruvian children. Pathog Dis 2016; 74:ftw054. [PMID: 27307104 DOI: 10.1093/femspd/ftw054] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/01/2016] [Indexed: 11/12/2022] Open
Abstract
Enteroaggregative Escherichia coli (EAEC) causes acute and persistent diarrhea among children, HIV-infected patients, and travelers to developing countries. We have searched for 18 genes-encoding virulence factors associated with aggregative adherence, dispersion, biofilm, toxins, serine protease autotransporters of Enterobacteriaceae (SPATEs) and siderophores, analyzed in 172 well-characterized EAEC strains (aggR(+)) isolated from stool samples of 97 children with diarrhea and 75 healthy controls from a passive surveillance diarrhea cohort study in Peru. Eighty-one different genetic profiles were identified, 37 were found only associated with diarrhea and 25 with control samples. The most frequent genetic profile was aggC(+)aatA(+)aap(+)shf(+)fyuA(+), present in 19 strains, including diarrhea and controls. The profile set1A(+)set1B(+)pic(+) was associated with diarrhea (P < 0.05). Of all genes evaluated, the most frequent were aatA (CVD 342) present in 159 strains (92.4%) and fyuA in 157 (91.3%). When EAEC strains were analyzed as a single pathogen (excluding co-infections), only pic was associated with diarrhea (P < 0.05) and with prolonged diarrhea (diarrhea ≥ 7 days) (P < 0.05). In summary, this is the first report on the prevalence of a large set of EAEC virulence genes and its association with diarrhea in Peruvian children. More studies are needed to elucidate the exact role of each virulence factor.
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Affiliation(s)
- David Durand
- Alexander von Humboldt Tropical Medicine Institute, Cayetano Heredia Peruvian University, 430 Honorio Delgado Avenue, Lima 31, Perú
| | - Carmen A Contreras
- Alexander von Humboldt Tropical Medicine Institute, Cayetano Heredia Peruvian University, 430 Honorio Delgado Avenue, Lima 31, Perú Department of Molecular Microbiology, Institute of Biotechnology, National Autonomous University of Mexico, Cuernavaca postal code 62210, México
| | - Susan Mosquito
- Alexander von Humboldt Tropical Medicine Institute, Cayetano Heredia Peruvian University, 430 Honorio Delgado Avenue, Lima 31, Perú
| | - Joaquim Ruíz
- ISGlobal, Barcelona Institute for Global Health, Barcelona Centre for International Health Research (CRESIB), Hospital Clinic of Barcelona, University of Barcelona, 08036 Barcelona, Spain
| | - Thomas G Cleary
- University of Texas Health Science Center at Houston, School of Public Health, Houston, TX 77030, USA
| | - Theresa J Ochoa
- Alexander von Humboldt Tropical Medicine Institute, Cayetano Heredia Peruvian University, 430 Honorio Delgado Avenue, Lima 31, Perú University of Texas Health Science Center at Houston, School of Public Health, Houston, TX 77030, USA
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Abstract
Escherichia colicauses three types of illnesses in humans: diarrhea, urinary tract infections, and meningitis in newborns. The acquisition of virulence-associated genes and the ability to properly regulate these, often horizontally transferred, loci distinguishes pathogens from the normally harmless commensal E. coli found within the human intestine. This review addresses our current understanding of virulence gene regulation in several important diarrhea-causing pathotypes, including enteropathogenic, enterohemorrhagic,enterotoxigenic, and enteroaggregativeE. coli-EPEC, EHEC, ETEC and EAEC, respectively. The intensely studied regulatory circuitry controlling virulence of uropathogenicE. coli, or UPEC, is also reviewed, as is that of MNEC, a common cause of meningitis in neonates. Specific topics covered include the regulation of initial attachment events necessary for infection, environmental cues affecting virulence gene expression, control of attaching and effacing lesionformation, and control of effector molecule expression and secretion via the type III secretion systems by EPEC and EHEC. How phage control virulence and the expression of the Stx toxins of EHEC, phase variation, quorum sensing, and posttranscriptional regulation of virulence determinants are also addressed. A number of important virulence regulators are described, including the AraC-like molecules PerA of EPEC, CfaR and Rns of ETEC, and AggR of EAEC;the Ler protein of EPEC and EHEC;RfaH of UPEC;and the H-NS molecule that acts to silence gene expression. The regulatory circuitry controlling virulence of these greatly varied E. colipathotypes is complex, but common themes offerinsight into the signals and regulators necessary forE. coli disease progression.
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Upadhyay A, Mooyottu S, Yin H, Nair MS, Bhattaram V, Venkitanarayanan K. Inhibiting Microbial Toxins Using Plant-Derived Compounds and Plant Extracts. MEDICINES (BASEL, SWITZERLAND) 2015; 2:186-211. [PMID: 28930207 PMCID: PMC5456214 DOI: 10.3390/medicines2030186] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 07/22/2015] [Accepted: 07/23/2015] [Indexed: 06/07/2023]
Abstract
Many pathogenic bacteria and fungi produce potentially lethal toxins that cause cytotoxicity or impaired cellular function either at the site of colonization or other locations in the body through receptor-mediated interactions. Various factors, including biotic and abiotic environments, competing microbes, and chemical cues affect toxin expression in these pathogens. Recent work suggests that several natural compounds can modulate toxin production in pathogenic microbes. However, studies explaining the mechanistic basis for their effect are scanty. This review discusses the potential of various plant-derived compounds for reducing toxin production in foodborne and other microbes. In addition, studies highlighting their anti-toxigenic mechanism(s) are discussed.
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Affiliation(s)
- Abhinav Upadhyay
- Department of Animal Science, University of Connecticut, Storrs, CT 06269, USA.
| | - Shankumar Mooyottu
- Department of Animal Science, University of Connecticut, Storrs, CT 06269, USA.
| | - Hsinbai Yin
- Department of Animal Science, University of Connecticut, Storrs, CT 06269, USA.
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Distribution of Virulence Genes, Enterotoxin and Biofilm Formation Among Enteroaggregative Escherichia Coli (EAEC) Strains Isolated From Stools of Children With Diarrhea in South East Iran. ARCHIVES OF PEDIATRIC INFECTIOUS DISEASES 2015. [DOI: 10.5812/pedinfect.29745v2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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37
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Epidemiology and clinical manifestations of enteroaggregative Escherichia coli. Clin Microbiol Rev 2015; 27:614-30. [PMID: 24982324 DOI: 10.1128/cmr.00112-13] [Citation(s) in RCA: 129] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Enteroaggregative Escherichia coli (EAEC) represents a heterogeneous group of E. coli strains. The pathogenicity and clinical relevance of these bacteria are still controversial. In this review, we describe the clinical significance of EAEC regarding patterns of infection in humans, transmission, reservoirs, and symptoms. Manifestations associated with EAEC infection include watery diarrhea, mucoid diarrhea, low-grade fever, nausea, tenesmus, and borborygmi. In early studies, EAEC was considered to be an opportunistic pathogen associated with diarrhea in HIV patients and in malnourished children in developing countries. In recent studies, associations with traveler's diarrhea, the occurrence of diarrhea cases in industrialized countries, and outbreaks of diarrhea in Europe and Asia have been reported. In the spring of 2011, a large outbreak of hemolytic-uremic syndrome (HUS) and hemorrhagic colitis occurred in Germany due to an EAEC O104:H4 strain, causing 54 deaths and 855 cases of HUS. This strain produces the potent Shiga toxin along with the aggregative fimbriae. An outbreak of urinary tract infection associated with EAEC in Copenhagen, Denmark, occurred in 1991; this involved extensive production of biofilm, an important characteristic of the pathogenicity of EAEC. However, the heterogeneity of EAEC continues to complicate diagnostics and also our understanding of pathogenicity.
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Expression of different bacterial cytotoxins is controlled by two global transcription factors, CRP and Fis, that co-operate in a shared-recruitment mechanism. Biochem J 2015; 466:323-35. [DOI: 10.1042/bj20141315] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Expression of related autotransporter toxin genes in pathogenic Escherichia coli and Shigella sonnei require the CRP and Fis global regulators. At promoters controlling toxin production, CRP is suboptimally positioned and Fis compensates for this impediment by facilitating RNA polymerase recruitment.
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Clayton JB, Danzeisen JL, Trent AM, Murphy T, Johnson TJ. Longitudinal Characterization of Escherichia coli in Healthy Captive Non-Human Primates. Front Vet Sci 2014; 1:24. [PMID: 26664923 PMCID: PMC4668849 DOI: 10.3389/fvets.2014.00024] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 10/31/2014] [Indexed: 11/25/2022] Open
Abstract
The gastrointestinal (GI) tracts of non-human primates (NHPs) are well known to harbor Escherichia coli, a known commensal of human beings and animals. While E. coli is a normal inhabitant of the mammalian gut, it also exists in a number of pathogenic forms or pathotypes, including those with predisposition for the GI tract as well as the urogenital tract. Diarrhea in captive NHPs has long been a problem in both zoo settings and research colonies, including the Como Zoo. It is an animal welfare concern, as well as a public health concern. E. coli has not been extensively studied; therefore, a study was performed during the summer of 2009 in collaboration with a zoo in Saint Paul, MN, which was previously experiencing an increased incidence and severity of diarrhea among their NHP collection. Fresh fecal samples were collected weekly from each member of the primate collection, between June and August of 2009, and E. coli were isolated. A total of 33 individuals were included in the study, representing eight species. E. coli isolates were examined for their genetic relatedness, phylogenetic relationships, plasmid replicon types, virulence gene profiles, and antimicrobial susceptibility profiles. A number of isolates were identified containing virulence genes commonly found in several different E. coli pathotypes, and there was evidence of clonal transmission of isolates between animals and over time. Overall, the manifestation of chronic diarrhea in the Como Zoo primate collection is a complex problem whose solution will require regular screening for microbial agents and consideration of environmental causes. This study provides some insight toward the sharing of enteric bacteria between such animals.
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Affiliation(s)
- Jonathan B Clayton
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota , Saint Paul, MN , USA
| | - Jessica L Danzeisen
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota , Saint Paul, MN , USA
| | - Ava M Trent
- Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota , Saint Paul, MN , USA
| | - Tami Murphy
- Como Park Zoo & Conservatory , Saint Paul, MN , USA
| | - Timothy J Johnson
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota , Saint Paul, MN , USA
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A mortise-tenon joint in the transmembrane domain modulates autotransporter assembly into bacterial outer membranes. Nat Commun 2014; 5:4239. [PMID: 24967730 DOI: 10.1038/ncomms5239] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 05/28/2014] [Indexed: 11/08/2022] Open
Abstract
Bacterial autotransporters comprise a 12-stranded membrane-embedded β-barrel domain, which must be folded in a process that entraps segments of an N-terminal passenger domain. This first stage of autotransporter folding determines whether subsequent translocation can deliver the N-terminal domain to its functional form on the bacterial cell surface. Here, paired glycine-aromatic 'mortise and tenon' motifs are shown to join neighbouring β-strands in the C-terminal barrel domain, and mutations within these motifs slow the rate and extent of passenger domain translocation to the surface of bacterial cells. In line with this, biophysical studies of the autotransporter Pet show that the conserved residues significantly quicken completion of the folding reaction and promote stability of the autotransporter barrel domain. Comparative genomics demonstrate conservation of glycine-aromatic residue pairings through evolution as a previously unrecognized feature of all autotransporter proteins.
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41
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Atypical enteropathogenic Escherichia coli secretes plasmid encoded toxin. BIOMED RESEARCH INTERNATIONAL 2014; 2014:896235. [PMID: 24949475 PMCID: PMC4037613 DOI: 10.1155/2014/896235] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Accepted: 04/13/2014] [Indexed: 02/06/2023]
Abstract
Plasmid encoded toxin (Pet) is a serine protease originally described in enteroaggregative Escherichia coli (EAEC) prototype strain 042 whose entire characterization was essentially obtained from studies performed with the purified toxin. Here we show that Pet is not exclusive to EAEC. Atypical enteropathogenic Escherichia coli (aEPEC) strains, isolated from diarrhea cases, express Pet and its detection in supernatants of infected HEp-2 cells coincides with the appearance of cell damage, which, in turn, were similar to those described with purified Pet. Pet secretion and the cytotoxic effects are time and culture medium dependent. In presence of DMEM supplemented with tryptone cell rounding and detachment were observed after just 5 h of incubation with the bacteria. In the absence of tryptone, the cytotoxic effects were detected only after 24 h of infection. We also show that, in addition to the prototype EAEC, other pet+ EAEC strains, also isolated from diarrhea cases, induce cellular damage in the same degree as the aEPEC. The cytotoxic effects of EAEC and aEPEC strains were significantly reduced in the presence of a serine protease inhibitor or anti-Pet IgG serum. Our results show a common aspect between the aEPEC and EAEC and provide the first evidence pointing to a role of Pet in aEPEC pathogenesis.
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42
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Domingo Meza-Aguilar J, Fromme P, Torres-Larios A, Mendoza-Hernández G, Hernandez-Chiñas U, Arreguin-Espinosa de Los Monteros RA, Eslava Campos CA, Fromme R. X-ray crystal structure of the passenger domain of plasmid encoded toxin(Pet), an autotransporter enterotoxin from enteroaggregative Escherichia coli (EAEC). Biochem Biophys Res Commun 2014; 445:439-44. [PMID: 24530907 DOI: 10.1016/j.bbrc.2014.02.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Accepted: 02/05/2014] [Indexed: 01/29/2023]
Abstract
Autotransporters (ATs) represent a superfamily of proteins produced by a variety of pathogenic bacteria, which include the pathogenic groups of Escherichia coli (E. coli) associated with gastrointestinal and urinary tract infections. We present the first X-ray structure of the passenger domain from the Plasmid-encoded toxin (Pet) a 100 kDa protein at 2.3 Å resolution which is a cause of acute diarrhea in both developing and industrialized countries. Pet is a cytoskeleton-altering toxin that induces loss of actin stress fibers. While Pet (pdb code: 4OM9) shows only a sequence identity of 50% compared to the closest related protein sequence, extracellular serine protease plasmid (EspP) the structural features of both proteins are conserved. A closer structural look reveals that Pet contains a β-pleaded sheet at the sequence region of residues 181-190, the corresponding structural domain in EspP consists of a coiled loop. Secondary, the Pet passenger domain features a more pronounced beta sheet between residues 135 and 143 compared to the structure of EspP.
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Affiliation(s)
- J Domingo Meza-Aguilar
- Departamento de Salud Pública Facultad de Medicina UNAM, Ciudad Universitaria Coyoacán 04510, D.F., Mexico; Laboratorio de Patogenicidad Bacteriana, Unidad de Hemato Oncología e Investigación, Hospital Infantil de México Federico Gómez 06720, D.F., Mexico
| | - Petra Fromme
- Department of Chemistry and Biochemistry, Arizona State University, Physical Sciences BLDG D-102, Tempe, AZ 85287, USA
| | - Alfredo Torres-Larios
- Instituto de Fisiología Celular UNAM, Ciudad Universitaria Coyoacán 04510, D.F., Mexico
| | | | - Ulises Hernandez-Chiñas
- Departamento de Salud Pública Facultad de Medicina UNAM, Ciudad Universitaria Coyoacán 04510, D.F., Mexico; Laboratorio de Patogenicidad Bacteriana, Unidad de Hemato Oncología e Investigación, Hospital Infantil de México Federico Gómez 06720, D.F., Mexico
| | | | - Carlos A Eslava Campos
- Departamento de Salud Pública Facultad de Medicina UNAM, Ciudad Universitaria Coyoacán 04510, D.F., Mexico; Laboratorio de Patogenicidad Bacteriana, Unidad de Hemato Oncología e Investigación, Hospital Infantil de México Federico Gómez 06720, D.F., Mexico
| | - Raimund Fromme
- Department of Chemistry and Biochemistry, Arizona State University, Physical Sciences BLDG D-102, Tempe, AZ 85287, USA.
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Cytokeratin 8 is an epithelial cell receptor for Pet, a cytotoxic serine protease autotransporter of Enterobacteriaceae. mBio 2013; 4:e00838-13. [PMID: 24327340 PMCID: PMC3870265 DOI: 10.1128/mbio.00838-13] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The group of proteins known as serine protease autotransporters of Enterobacteriaceae (SPATE) is a growing family of serine proteases secreted to the external milieu by the type V secretion system. Pet toxin and some other SPATE belong to the class 1 cytotoxic SPATE, which have comparable protease strength on fodrin. Pet is internalized and is directed to its intracellular substrate by retrograde transport. However, the epithelial cell receptor for Pet has yet to be identified. We show that Pet has affinity for the epithelial cell surface until the saturation of the binding sites at 100 nM Pet. Affinity column assays and matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) analysis identified a cytokeratin (CK8) which directly binds to Pet, and both proteins colocalized on the cell surface. Interestingly, CK8 is not present in kidney cell lines, which are not susceptible to Pet. Inhibition experiments by using anti-CK8 and ck8 small interfering RNA (siRNA) blocked the cytotoxic effect induced by Pet, while exogenous CK8 expression in kidney cells made them susceptible to Pet intoxication. Recombinant CK8 showed a Pet-binding pattern similar to that seen by using fixed cells. Remarkably, Pet colocalized with CK8 and clathrin at early times (receptor-mediated endocytosis), and subsequently, Pet colocalized with CK8 and Rab5b in the early endosomes. These data support the idea that CK8 is an important receptor for Pet on epithelial cells for starting its cytotoxic effects. These data suggest that therapeutics that block Pet-CK8 interaction may improve outcome of diseases caused by Pet-secreting Enterobacteriaceae such as enteroaggregative Escherichia coli. Receptor-ligand binding is one mechanism by which cells sense and respond to external cues. Receptors may also be utilized by toxins to mediate their own internalization. Pet toxin is secreted by enteroaggregative Escherichia coli, an organism that causes persistent diarrhea in children, traveler’s diarrhea, and acute and persistent diarrhea in patients with HIV. Pet is a member of the family of serine protease autotransporters of Enterobacteriaceae (SPATE). SPATE in different pathogens are virulence factors, and Pet belongs to the class 1 cytotoxic SPATE, which have comparable protease strength on their biological substrate, fodrin (a cytoskeletal protein important for maintaining cell viability). To cleave fodrin, Pet enters the cells by clathrin-mediated endocytosis. This mechanism includes receptor-mediated endocytosis (a receptor-ligand complex triggers the endocytosis). We show that CK8 is an important receptor for Pet on epithelial cells and that it may be useful for identifying molecules that block the interaction of CK8 with Pet.
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44
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Besingi RN, Chaney JL, Clark PL. An alternative outer membrane secretion mechanism for an autotransporter protein lacking a C-terminal stable core. Mol Microbiol 2013; 90:1028-45. [PMID: 24118465 DOI: 10.1111/mmi.12414] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/24/2013] [Indexed: 01/24/2023]
Abstract
Autotransporter (AT) proteins are a broad class of virulence factors from Gram-negative pathogens. AT outer membrane (OM) secretion appears simple in many regards, yet the mechanism that enables transport of the central AT 'passenger' across the OM remains unclear. OM secretion efficiency for two AT passengers is enhanced by approximately 20 kDa stable core at the C-terminus of the passenger, but studies on a broader range of AT proteins are needed in order to determine whether a stability difference between the passenger N- and C-terminus represents a truly common mechanistic feature. Yersinia pestis YapV is homologous to Shigella flexneri IcsA, and like IcsA, YapV recruits mammalian neural Wiskott-Aldrich syndrome protein (N-WASP). In vitro, the purified YapV passenger is functional and rich in β-sheet structure, but lacks a approximately 20 kDa C-terminal stable core. However, the N-terminal 49 residues of the YapV passenger globally destabilize the entire YapV passenger, enhancing its OM secretion efficiency. These results indicate that the contributions of AT passenger sequences to OM secretion efficiency extend beyond a C-terminal stable core, and highlight a role of the passenger N-terminus in reducing passenger stability in order to facilitate OM secretion of some AT proteins.
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Affiliation(s)
- Richard N Besingi
- Department of Chemistry & Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, USA
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45
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Jandhyala DM, Vanguri V, Boll EJ, Lai Y, McCormick BA, Leong JM. Shiga toxin-producing Escherichia coli O104:H4: an emerging pathogen with enhanced virulence. Infect Dis Clin North Am 2013; 27:631-49. [PMID: 24011834 PMCID: PMC3800737 DOI: 10.1016/j.idc.2013.05.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Pathogenic Escherichia coli are genetically diverse and encompass a broad variety of pathotypes, such as enteroaggregative E. coli (EAEC) or enterohemorrhagic E. coli (EHEC), which cause distinct clinical syndromes. The historically large 2011 German outbreak of hemolytic uremic syndrome (HUS), caused by a Shiga-toxin producing E. coli (STEC) of the serotype O104:H4, illustrated the emerging importance of non-O157 STEC. STEC O104:H4, with features characteristic of both enteroaggregative E. coli and enterohemorrhagic E. coli, represents a unique and highly virulent pathotype. The German outbreak both allowed for the evaluation of several potential therapeutic approaches to STEC-induced HUS and emphasizes the importance of early and specific detection of both O157 and non-O157 STEC.
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Affiliation(s)
- Dakshina M Jandhyala
- Division of Geographic Medicine and Infectious Diseases, Tufts Medical Center, 750 Washington Street, Boston, MA 02111, USA.
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46
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Ruiz-Perez F, Nataro JP. Bacterial serine proteases secreted by the autotransporter pathway: classification, specificity, and role in virulence. Cell Mol Life Sci 2013; 71:745-70. [PMID: 23689588 DOI: 10.1007/s00018-013-1355-8] [Citation(s) in RCA: 106] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Revised: 04/25/2013] [Accepted: 04/29/2013] [Indexed: 01/07/2023]
Abstract
Serine proteases exist in eukaryotic and prokaryotic organisms and have emerged during evolution as the most abundant and functionally diverse group. In Gram-negative bacteria, there is a growing family of high molecular weight serine proteases secreted to the external milieu by a fascinating and widely employed bacterial secretion mechanism, known as the autotransporter pathway. They were initially found in Neisseria, Shigella, and pathogenic Escherichia coli, but have now also been identified in Citrobacter rodentium, Salmonella, and Edwardsiella species. Here, we focus on proteins belonging to the serine protease autotransporter of Enterobacteriaceae (SPATEs) family. Recent findings regarding the predilection of serine proteases to host intracellular or extracellular protein-substrates involved in numerous biological functions, such as those implicated in cytoskeleton stability, autophagy or innate and adaptive immunity, have helped provide a better understanding of SPATEs' contributions in pathogenesis. Here, we discuss their classification, substrate specificity, and potential roles in pathogenesis.
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Affiliation(s)
- Fernando Ruiz-Perez
- Department of Pediatrics, School of Medicine, University of Virginia, P.O.Box 800326, MR4 Room 4012C, 409 Lane Road, Charlottesville, VA, 22908, USA,
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47
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Grijpstra J, Arenas J, Rutten L, Tommassen J. Autotransporter secretion: varying on a theme. Res Microbiol 2013; 164:562-82. [PMID: 23567321 DOI: 10.1016/j.resmic.2013.03.010] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Accepted: 02/28/2013] [Indexed: 10/27/2022]
Abstract
Autotransporters are widely distributed among Gram-negative bacteria. They can have a large variety of functions and many of them have a role in virulence. They are synthesized as large precursors with an N-terminal signal sequence that mediates transport across the inner membrane via the Sec machinery and a translocator domain that mediates the transport of the connected passenger domain across the outer membrane to the bacterial cell surface. Like integral outer membrane proteins, the translocator domain folds in a β-barrel structure and requires the Bam machinery for its insertion into the outer membrane. After transport across the outer membrane, the passenger may stay connected via the translocator domain to the bacterial cell surface or it is proteolytically released into the extracellular milieu. Based on the size of the translocator domain and its position relative to the passenger in the precursor, autotransporters are divided into four sub-categories. We review here the current knowledge of the biogenesis, structure and function of various autotransporters.
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Affiliation(s)
- Jan Grijpstra
- Section Molecular Microbiology, Department of Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.
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48
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Weiss A, Brockmeyer J. Prevalence, biogenesis, and functionality of the serine protease autotransporter EspP. Toxins (Basel) 2012; 5:25-48. [PMID: 23274272 PMCID: PMC3564066 DOI: 10.3390/toxins5010025] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Revised: 12/18/2012] [Accepted: 12/21/2012] [Indexed: 11/24/2022] Open
Abstract
Enterohemorrhagic E. coli (EHEC) causes severe diseases in humans worldwide. One of its virulence factors is EspP, which belongs to the serine protease autotransporters of Enterobacteriaceae (SPATE) family. In this review we recapitulate the current data on prevalence, biogenesis, structural properties and functionality. EspP has been used to investigate mechanistic details of autotransport, and recent studies indicate that this transport mechanism is not autonomous but rather dependent on additional factors. Currently, five subtypes have been identified (EspPα-EspPε), with EspPα being associated with highly virulent EHEC serotypes and isolates from patients with severe disease. EspPα has been shown to degrade major proteins of the complement cascade, namely C3 and C5 and probably interferes with hemostasis by cleavage of coagulation factor V. Furthermore, EspPα is believed to contribute to biofilm formation perhaps by polymerization to rope-like structures. Together with the proteolytic activity, EspPα might ameliorate host colonization and interfere with host response.
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Affiliation(s)
- André Weiss
- Institute of Food Chemistry, Corrensstraße 45, Münster 48149, Germany.
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49
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Autotransporter protein-encoding genes of diarrheagenic Escherichia coli are found in both typical and atypical enteropathogenic E. coli strains. Appl Environ Microbiol 2012; 79:411-4. [PMID: 23104414 DOI: 10.1128/aem.02635-12] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Autotransporter (AT) protein-encoding genes of diarrheagenic Escherichia coli (DEC) pathotypes (cah, eatA, ehaABCDJ, espC, espI, espP, pet, pic, sat, and tibA) were detected in typical and atypical enteropathogenic E. coli (EPEC) in frequencies between 0.8% and 39.3%. Although these ATs have been described in particular DEC pathotypes, their presence in EPEC indicates that they should not be considered specific virulence markers.
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50
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Estrada-Garcia T, Navarro-Garcia F. Enteroaggregative Escherichia coli pathotype: a genetically heterogeneous emerging foodborne enteropathogen. ACTA ACUST UNITED AC 2012; 66:281-98. [PMID: 22775224 DOI: 10.1111/j.1574-695x.2012.01008.x] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Revised: 07/03/2012] [Accepted: 07/03/2012] [Indexed: 11/28/2022]
Abstract
Until now, a common feature that defines the enteroaggregative Escherichia coli (EAEC) strains is the ability to produce a 'stacked-brick' appearance on epithelial cells, but it does not distinguish between pathogenic and nonpathogenic strains. Numerous adhesins, toxins, and proteins associated with virulence have been described, as well as multiple factors contributing to EAEC-induced inflammation. None of these factors are found in all EAEC isolates, and no single factor has ever been implicated in EAEC virulence. The European outbreak of Shiga-toxin-producing EAEC raises its pathogenic potential and interest on finding the true pathogenic factors that may define this pathotype. EAEC were first associated with persistent diarrhea in infants from developing countries, since then they have increasingly been linked as a cause of acute and persistent diarrhea in young infants and children in developing and industrialized countries, individuals infected with human immunodeficiency virus, as a cause of acute diarrhea in travelers from industrialized regions, and with foodborne outbreaks. A major effect of EAEC infection is on the malnourished children in developing countries. Here, we will discuss the EAEC public health relevance and their complexity because of the strain heterogeneity regarding their pathogenesis, identification, diagnosis, lineage, epidemiology, and clinical manifestations.
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Affiliation(s)
- Teresa Estrada-Garcia
- Department of Molecular Biomedicine, Centro de Investigación y de Estudios Avanzados del IPN, México DF, Mexico
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