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Kaur P, Dudeja PK. Pathophysiology of Enteropathogenic Escherichia coli-induced Diarrhea. NEWBORN (CLARKSVILLE, MD.) 2023; 2:102-113. [PMID: 37388762 PMCID: PMC10308259 DOI: 10.5005/jp-journals-11002-0056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 07/01/2023]
Abstract
Enteropathogenic Escherichia coli (EPEC) are important diarrheal pathogens of infants and young children. Since the availability of molecular diagnosis methods, we now have new insights into the incidence and prevalence of these infections. Recent epidemiological studies indicate that atypical EPEC (aEPEC) are seen more frequently than typical EPEC (tEPEC) worldwide, including in both endemic diarrhea and diarrhea outbreaks. Therefore, it is important to further characterize the pathogenicity of these emerging strains. The virulence mechanisms and pathophysiology of the attaching and effacing lesion (A/E) and the type-three-secretion-system (T3SS) are complex but well-studied. A/E strains use their pool of locus of enterocyte effacement (LEE)-encoded and non-LEE-encoded effector proteins to subvert and modulate cellular and barrier properties of the host. However, the exact mechanisms of diarrhea in EPEC infection are not completely understood. From the clinical perspective, there is a need for fast, easy, and inexpensive diagnostic methods to define optimal treatment and prevention for children in endemic areas. In this article, we present a review of the classification of EPEC, epidemiology, pathogenesis of the disease caused by these bacteria, determinants of virulence, alterations in signaling, determinants of colonization vs. those of disease, and the limited information we have on the pathophysiology of EPEC-induced diarrhea. This article combines peer-reviewed evidence from our own studies and the results of an extensive literature search in the databases PubMed, EMBASE, and Scopus.
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Affiliation(s)
- Prabhdeep Kaur
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Illinois, United States of America
| | - Pradeep K Dudeja
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois; Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois, United States of America
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Human milk glycosaminoglycans inhibit in vitro the adhesion of Escherichia coli and Salmonella fyris to human intestinal cells. Pediatr Res 2016; 79:603-7. [PMID: 26679156 DOI: 10.1038/pr.2015.262] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 09/29/2015] [Indexed: 11/08/2022]
Abstract
BACKGROUND Breast-fed infants have a lower incidence of acute gastroenteritis due to the presence of several anti-infective factors in human milk. The aim of this work is to study the capacity of human milk glycosaminoglycans (GAGs) to inhibit the adhesion of some common pathogenic bacteria. METHODS GAGs were isolated from a pool of milk samples collected from different mothers during the first month of lactation. Experiments were carried out to study the ability of GAGs to inhibit the adhesion of two intestinal micro-organisms (enteropathogenic Escherichia coli serotype 0119 and Salmonella fyris) to Caco-2 and Int-407 cell lines. RESULTS The study showed that the GAGs had an anti-adhesive effect on the two pathogenic strains studied with different degrees of inhibition. In particular, in the presence of human milk GAGs, the adhesion of S. fyris to Caco-2 cells and to Int-407 cells of both tested strains was significantly reduced. CONCLUSION Our results demonstrated that GAGs in human milk can be one of the important defensive factors against acute diarrheal infections in breast-fed infants.
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Garcia BG, Ooka T, Gotoh Y, Vieira MAM, Yamamoto D, Ogura Y, Girão DM, Sampaio SCF, Melo AB, Irino K, Hayashi T, Gomes TAT. Genetic relatedness and virulence properties of enteropathogenic Escherichia coli strains of serotype O119:H6 expressing localized adherence or localized and aggregative adherence-like patterns on HeLa cells. Int J Med Microbiol 2016; 306:152-64. [PMID: 27083266 DOI: 10.1016/j.ijmm.2016.02.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Revised: 02/01/2016] [Accepted: 02/25/2016] [Indexed: 10/22/2022] Open
Abstract
Enteropathogenic Escherichia coli (EPEC) induce attaching and effacing (A/E) lesions in enterocytes and produce the bundle-forming pilus (BFP) contributing to the localized adherence (LA) pattern formation on HeLa cells. Enteroaggregative E. coli (EAEC) produce aggregative adherence (AA) on HeLa cells and form prominent biofilms. The ability to produce LA or AA is an important hallmark to classify fecal E. coli isolates as EPEC or EAEC, respectively. E. coli strains of serotype O119:H6 exhibit an LA+ phenotype and have been considered as comprising a clonal group of EPEC strains. However, we have recently identified O119:H6 EPEC strains that produce LA and an AA-like pattern concurrently (LA/AA-like+). In this study, we evaluated the relatedness of three LA/AA-like+ and three LA+ O119:H6 strains by comparing their virulence and genotypic properties. We first found that the LA/AA-like+ strains induced actin accumulation in HeLa cells (indicative of A/E lesions formation) and formed biofilms on abiotic surfaces more efficiently than the LA+ strains. MLST analysis showed that the six strains all belong to the ST28 complex. All strains carried multiple plasmids, but as plasmid profiles were highly variable, this cannot be used to differentiate LA/AA-like+ and LA+ strains. We further obtained their draft genome sequences and the complete sequences of four plasmids harbored by one LA/AA-like+ strain. Analysis of these sequences and comparison with 37 fully sequenced E. coli genomes revealed that both O119:H6 groups belong to the E. coli phylogroup B2 and are very closely related with only 58-67 SNPs found between LA/AA-like+ and LA+ strains. Search of the draft sequences of the six strains for adhesion-related genes known in EAEC and other E. coli pathotypes detected no genes specifically present in LA/AA-like+ strains. Unexpectedly however, we found that a large plasmid distinct from pEAF is responsible for the AA-like phenotype of the LA/AA-like+ strains. Although we have not identified any plasmid genes specifically present in all LA/AA-like+ strains and absent in the LA+ strains, these results suggest the presence of an unknown mechanism to promote the AA-like pattern production and biofilm formation by the LA/AA-like+ strains. Because their ability to produce A/E lesions and biofilm concomitantly could exacerbate the clinical condition of the patient and lead to persistent diarrhea, the mechanism underlying the enhanced biofilm formation by the LA/AA-like+ O119:H6 strains and their spread and involvement in severe diarrheal diseases should be more intensively investigated.
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Affiliation(s)
- Bruna G Garcia
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo-Escola Paulista de Medicina, São Paulo, Brazil.
| | - Tadasuke Ooka
- Department of Microbiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan.
| | - Yasuhiro Gotoh
- Department of Infectious Diseases, Division of Microbiology, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan.
| | - Mônica A M Vieira
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo-Escola Paulista de Medicina, São Paulo, Brazil.
| | - Denise Yamamoto
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo-Escola Paulista de Medicina, São Paulo, Brazil.
| | - Yoshitoshi Ogura
- Department of Bacteriology, Faculty of Medical Sciences, Kyushu University, Fukuoka, Japan.
| | - Dennys M Girão
- Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Prof. Paulo de Góes, Centro de Ciências da Saúde-Ilha do Fundão, Rio de Janeiro, Brazil.
| | - Suely C F Sampaio
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo-Escola Paulista de Medicina, São Paulo, Brazil.
| | - Alexis Bonfim Melo
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo-Escola Paulista de Medicina, São Paulo, Brazil.
| | - Kinue Irino
- Seção de Bacteriologia, Instituto Adolfo Lutz, Secretaria de Estado da Saúde, São Paulo, Brazil.
| | - Tetsuya Hayashi
- Department of Infectious Diseases, Division of Microbiology, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan.
| | - Tânia A T Gomes
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo-Escola Paulista de Medicina, São Paulo, Brazil.
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Late establishment of the attaching and effacing lesion caused by atypical enteropathogenic Escherichia coli depends on protein expression regulated by Per. Infect Immun 2014; 83:379-88. [PMID: 25385791 DOI: 10.1128/iai.02563-14] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Enteropathogenic Escherichia coli (EPEC) is classified as typical (tEPEC) or atypical (aEPEC) based on the presence or absence of the E. coli adherence factor plasmid (pEAF), respectively. The hallmark of EPEC infection is the formation of the attaching and effacing (A/E) lesions on the gut mucosa. We compared the kinetics of A/E lesion formation induced by aEPEC and tEPEC. The examination of infected HEp-2 cells clearly demonstrated delayed A/E lesion formation by aEPEC in comparison to tEPEC. This delay was associated with the expression of locus of enterocyte effacement (LEE)-encoded virulence factors (i.e., intimin and EspD). Indeed, the insertion of a plasmid containing perABC, a transcriptional regulator of virulence factors involved in A/E formation, into aEPEC strains increased and accelerated the formation of A/E lesions. Interestingly, the enhanced expression and translocation of LEE-encoded proteins, such as those expressed in LEE5 (intimin) and LEE4 (EspD), in aEPEC (perABC) was independent of bacterial adhesion. The secretion kinetics of these two proteins representing LEE5 and LEE4 expression correlated with A/E lesion formation. We conclude that the lack of Per in the regulation network of virulence genes is one of the main factors that delay the establishment of A/E lesions induced by aEPEC strains.
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Pathogenesis of human enterovirulent bacteria: lessons from cultured, fully differentiated human colon cancer cell lines. Microbiol Mol Biol Rev 2014; 77:380-439. [PMID: 24006470 DOI: 10.1128/mmbr.00064-12] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Hosts are protected from attack by potentially harmful enteric microorganisms, viruses, and parasites by the polarized fully differentiated epithelial cells that make up the epithelium, providing a physical and functional barrier. Enterovirulent bacteria interact with the epithelial polarized cells lining the intestinal barrier, and some invade the cells. A better understanding of the cross talk between enterovirulent bacteria and the polarized intestinal cells has resulted in the identification of essential enterovirulent bacterial structures and virulence gene products playing pivotal roles in pathogenesis. Cultured animal cell lines and cultured human nonintestinal, undifferentiated epithelial cells have been extensively used for understanding the mechanisms by which some human enterovirulent bacteria induce intestinal disorders. Human colon carcinoma cell lines which are able to express in culture the functional and structural characteristics of mature enterocytes and goblet cells have been established, mimicking structurally and functionally an intestinal epithelial barrier. Moreover, Caco-2-derived M-like cells have been established, mimicking the bacterial capture property of M cells of Peyer's patches. This review intends to analyze the cellular and molecular mechanisms of pathogenesis of human enterovirulent bacteria observed in infected cultured human colon carcinoma enterocyte-like HT-29 subpopulations, enterocyte-like Caco-2 and clone cells, the colonic T84 cell line, HT-29 mucus-secreting cell subpopulations, and Caco-2-derived M-like cells, including cell association, cell entry, intracellular lifestyle, structural lesions at the brush border, functional lesions in enterocytes and goblet cells, functional and structural lesions at the junctional domain, and host cellular defense responses.
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Specific properties of enteropathogenic Escherichia coli isolates from diarrheal patients and comparison to strains from foods and fecal specimens from cattle, swine, and healthy carriers in Osaka City, Japan. Appl Environ Microbiol 2012; 79:1232-40. [PMID: 23220963 DOI: 10.1128/aem.03380-12] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
For exhaustive detection of diarrheagenic Escherichia coli, we previously developed a colony-hybridization method using hydrophobic grid-membrane filters in combination with multiplex real-time PCR. To assess the role of domestic animals as the source of atypical enteropathogenic E. coli (aEPEC), a total of 679 samples (333 from foods, fecal samples from 227 domestic animals, and 119 from healthy people) were examined. Combining 48 strains previously isolated from patients and carriers, 159 aEPEC strains were classified by phylogroup, virulence profile, and intimin typing. Phylogroup B1 was significantly more prevalent among aEPEC from patients (50%) and bovine samples (79%) than from healthy carriers (16%) and swine strains (23%), respectively. Intimin type β1 was predominant in phylogroup B1; B1-β1 strains comprised 26% of bovine strains and 25% of patient strains. The virulence profile groups Ia and Ib were also observed more frequently among bovine strains than among porcine strains. Similarly, virulence group Ia was detected more frequently among patient strains than strains of healthy carriers. A total of 85 strains belonged to virulence group I, and 63 of these strains (74%) belonged to phylogroup B1. The present study suggests that the etiologically important aEPEC in diarrheal patients could be distinguished from aEPEC strains indigenous to humans based on type, such as B1, Ia, and β1/γ1, which are shared with bovine strains, while the aEPEC strains in healthy humans are different, and some of these were also present in porcine samples.
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Moura RA, Sircili MP, Leomil L, Matté MH, Trabulsi LR, Elias WP, Irino K, Pestana de Castro AF. Clonal relationship among atypical enteropathogenic Escherichia coli strains isolated from different animal species and humans. Appl Environ Microbiol 2009; 75:7399-408. [PMID: 19801470 PMCID: PMC2786407 DOI: 10.1128/aem.00636-09] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Forty-nine typical and atypical enteropathogenic Escherichia coli (EPEC) strains belonging to different serotypes and isolated from humans, pets (cats and dogs), farm animals (bovines, sheep, and rabbits), and wild animals (monkeys) were investigated for virulence markers and clonal similarity by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). The virulence markers analyzed revealed that atypical EPEC strains isolated from animals have the potential to cause diarrhea in humans. A close clonal relationship between human and animal isolates was found by MLST and PFGE. These results indicate that these animals act as atypical EPEC reservoirs and may represent sources of infection for humans. Since humans also act as a reservoir of atypical EPEC strains, the cycle of mutual infection of atypical EPEC between animals and humans, mainly pets and their owners, cannot be ruled out since the transmission dynamics between the reservoirs are not yet clearly understood.
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Affiliation(s)
- Rodrigo A. Moura
- Laboratory of Human and Veterinary Bacteriology, Biomedical Sciences Institute, University of São Paulo, São Paulo, SP, Brazil, Laboratory of Bacteriology, Butantan Institute, São Paulo, SP, Brazil, Laboratory of Public Health, Public Health School, University of São Paulo, São Paulo, SP, Brazil, Adolfo Lutz Institute, São Paulo, SP, Brazil
| | - Marcelo P. Sircili
- Laboratory of Human and Veterinary Bacteriology, Biomedical Sciences Institute, University of São Paulo, São Paulo, SP, Brazil, Laboratory of Bacteriology, Butantan Institute, São Paulo, SP, Brazil, Laboratory of Public Health, Public Health School, University of São Paulo, São Paulo, SP, Brazil, Adolfo Lutz Institute, São Paulo, SP, Brazil
| | - Luciana Leomil
- Laboratory of Human and Veterinary Bacteriology, Biomedical Sciences Institute, University of São Paulo, São Paulo, SP, Brazil, Laboratory of Bacteriology, Butantan Institute, São Paulo, SP, Brazil, Laboratory of Public Health, Public Health School, University of São Paulo, São Paulo, SP, Brazil, Adolfo Lutz Institute, São Paulo, SP, Brazil
| | - Maria Helena Matté
- Laboratory of Human and Veterinary Bacteriology, Biomedical Sciences Institute, University of São Paulo, São Paulo, SP, Brazil, Laboratory of Bacteriology, Butantan Institute, São Paulo, SP, Brazil, Laboratory of Public Health, Public Health School, University of São Paulo, São Paulo, SP, Brazil, Adolfo Lutz Institute, São Paulo, SP, Brazil
| | - Luiz R. Trabulsi
- Laboratory of Human and Veterinary Bacteriology, Biomedical Sciences Institute, University of São Paulo, São Paulo, SP, Brazil, Laboratory of Bacteriology, Butantan Institute, São Paulo, SP, Brazil, Laboratory of Public Health, Public Health School, University of São Paulo, São Paulo, SP, Brazil, Adolfo Lutz Institute, São Paulo, SP, Brazil
| | - Waldir P. Elias
- Laboratory of Human and Veterinary Bacteriology, Biomedical Sciences Institute, University of São Paulo, São Paulo, SP, Brazil, Laboratory of Bacteriology, Butantan Institute, São Paulo, SP, Brazil, Laboratory of Public Health, Public Health School, University of São Paulo, São Paulo, SP, Brazil, Adolfo Lutz Institute, São Paulo, SP, Brazil
| | - Kinue Irino
- Laboratory of Human and Veterinary Bacteriology, Biomedical Sciences Institute, University of São Paulo, São Paulo, SP, Brazil, Laboratory of Bacteriology, Butantan Institute, São Paulo, SP, Brazil, Laboratory of Public Health, Public Health School, University of São Paulo, São Paulo, SP, Brazil, Adolfo Lutz Institute, São Paulo, SP, Brazil
| | - Antonio F. Pestana de Castro
- Laboratory of Human and Veterinary Bacteriology, Biomedical Sciences Institute, University of São Paulo, São Paulo, SP, Brazil, Laboratory of Bacteriology, Butantan Institute, São Paulo, SP, Brazil, Laboratory of Public Health, Public Health School, University of São Paulo, São Paulo, SP, Brazil, Adolfo Lutz Institute, São Paulo, SP, Brazil
- Corresponding author. Mailing address: Departamento de Microbiologia, Instituto de Ciências Biomédicas, Avenida Prof. Lineu Prestes 1374, 05508-900 São Paulo, SP, Brazil. Phone: 5511 3091-7298. Fax: 5511 3091-7354. E-mail:
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Nara JM, Cianciarullo AM, Culler HF, Bueris V, Horton DSPQ, Menezes MA, Franzolin MR, Elias WP, Piazza RMF. Differentiation of typical and atypical enteropathogenic Escherichia coli using colony immunoblot for detection of bundle-forming pilus expression. J Appl Microbiol 2009; 109:35-43. [PMID: 19968733 DOI: 10.1111/j.1365-2672.2009.04625.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
AIMS The aim of study was to develop a colony immunoblot assay to differentiate typical from atypical enteropathogenic Escherichia coli (EPEC) by detection of bundle-forming pilus (BFP) expression. METHODS AND RESULTS Anti-BFP antiserum was raised in rabbits and its reactivity was confirmed by immunoelectron microscopy and by immunoblotting recognizing bundlin, the major pilus repeating subunit. The bacterial isolates tested in the colony immunoblot assay were grown in different media. Proteins from bacterial isolates were transferred to nitrocellulose membrane after treatment with phosphate buffer containing Triton X-100, EDTA and sodium chloride salts. When 24 typical EPEC and 96 isolates including, 72 atypical EPEC, 13 Gram-negative type IV-expressing strains and 11 enterobacteriaceae were cultivated in Dulbecco's Modified Eagle's Medium agar containing fetal bovine serum or in blood agar in the presence of CaCl(2) , they showed a positivity of 92 and 83%, and specificity of 96 and 97%, respectively. CONCLUSION The assay enables reliable identification of BFP-expressing isolates and contributes to the differentiation of typical and atypical EPEC. SIGNIFICANCE AND IMPACT OF THE STUDY The colony immunoblot for BFP detection developed in this study combines the simplicity of an immunoserological assay with the high efficiency of testing a large number of EPEC colonies.
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Affiliation(s)
- J M Nara
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, SP, Brazil
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Menezes MA, Rocha LB, Koga PCM, Fernandes I, Nara JM, Magalhães CA, Abe CM, Ayala CO, Burgos YK, Elias WP, Castro AFP, Piazza RMF. Identification of enteropathogenic and enterohaemorrhagic Escherichia coli strains by immunoserological detection of intimin. J Appl Microbiol 2009; 108:878-887. [PMID: 19709337 DOI: 10.1111/j.1365-2672.2009.04484.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIMS To evaluate the sensitivity and specificity of polyclonal and monoclonal antibodies (Mabs) against intimin in the detection of enteropathogenic and enterohaemorrhagic Escherichia coli isolates using immunoblotting. METHODS AND RESULTS Polyclonal and Mabs against the intimin-conserved region were raised, and their reactivities were compared in enteropathogenic E. coli (EPEC) and enterohaemorrhagic E. coli (EHEC) isolates using immunoblotting analysis. In comparison with rat antiserum, rabbit anti-intimin IgG-enriched fraction had a stronger recognition pattern to a wide spectrum of intimin types in different EPEC and EHEC serotypes. On the other hand, murine monoclonal IgG2b specific to intimin, with dissociation constant of 1.3x10(-8) mol l(-1), failed in the detection of some of these isolates. CONCLUSION All employed antibodies showed 100% specificity, not reacting with any of the eae-negative isolates. The sensitivity range was according to the employed antisera, and 97% for rabbit anti-intimin IgG-enriched fraction, followed by 92% and 78% sensitivity with rat antisera and Mab. SIGNIFICANCE AND IMPACT OF THE STUDY The rabbit anti-intimin IgG-enriched fraction in immunoblotting analysis is a useful tool for EPEC and EHEC diagnoses.
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Affiliation(s)
- M A Menezes
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, SP, Brazil
| | - L B Rocha
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, SP, Brazil
| | - P C M Koga
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, SP, Brazil
| | - I Fernandes
- Laboratório de Imunopatologia, Instituto Butantan, São Paulo, SP, Brazil
| | - J M Nara
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, SP, Brazil
| | - C A Magalhães
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, SP, Brazil
| | - C M Abe
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, SP, Brazil
| | - C O Ayala
- Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Y K Burgos
- Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP, Brazil
| | - W P Elias
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, SP, Brazil
| | - A F P Castro
- Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP, Brazil
| | - R M F Piazza
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, SP, Brazil
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Oliveira MG, Brito JRF, Carvalho RR, Guth BEC, Gomes TAT, Vieira MAM, Kato MAMF, Ramos II, Vaz TMI, Irino K. Water buffaloes (Bubalus bubalis) identified as an important reservoir of Shiga toxin-producing Escherichia coli in Brazil. Appl Environ Microbiol 2007; 73:5945-8. [PMID: 17644639 PMCID: PMC2074925 DOI: 10.1128/aem.00929-07] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The presence of Shiga toxin-producing Escherichia coli (STEC) in water buffaloes is reported for the first time in South America. The prevalence of STEC ranged from 0 to 64% depending on the farm. STEC isolates exhibiting the genetic profiles stx(1)stx(2)ehxA iha saa and stx(2)ehxA iha saa predominated. Of the 20 distinct serotypes identified, more than 50% corresponded to serotypes associated with human diseases.
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Bando SY, Trabulsi LR, Moreira-Filho CA. Genetic relationship of diarrheagenic Escherichia coli pathotypes among the enteropathogenic Escherichia coli O serogroup. Mem Inst Oswaldo Cruz 2007; 102:169-74. [PMID: 17426881 DOI: 10.1590/s0074-02762007005000018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2006] [Indexed: 11/21/2022] Open
Abstract
The genetic relationship among the Escherichia coli pathotypes was investigated. We used random amplified polymorphic DNA (RAPD) data for constructing a dendrogram of 73 strains of diarrheagenic E. coli. A phylogenetic tree encompassing 15 serotypes from different pathotypes was constructed using multilocus sequence typing data. Phylogram clusters were used for validating RAPD data on the clonality of enteropathogenic E. coli (EPEC) O serogroup strains. Both analyses showed very similar topologies, characterized by the presence of two major groups: group A includes EPEC H6 and H34 strains and group B contains the other EPEC strains plus all serotypes belonging to atypical EPEC, enteroaggregative E. coli (EAEC) and enterohemorrhagic E. coli (EHEC). These results confirm the existence of two evolutionary divergent groups in EPEC: one is genetically and serologically very homogeneous whereas the other harbors EPEC and non-EPEC serotypes. The same situation was found for EAEC and EHEC.
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Affiliation(s)
- Silvia Y Bando
- Departamento de Imunologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brasil
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Lacher DW, Steinsland H, Blank TE, Donnenberg MS, Whittam TS. Molecular evolution of typical enteropathogenic Escherichia coli: clonal analysis by multilocus sequence typing and virulence gene allelic profiling. J Bacteriol 2006; 189:342-50. [PMID: 17098897 PMCID: PMC1797380 DOI: 10.1128/jb.01472-06] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Enteropathogenic Escherichia coli (EPEC) infections are a leading cause of infantile diarrhea in developing nations. Typical EPEC isolates are differentiated from other types of pathogenic E. coli by two distinctive phenotypes, attaching effacement and localized adherence. The genes specifying these phenotypes are found on the locus of enterocyte effacement (LEE) and the EPEC adherence factor (EAF) plasmid. To describe how typical EPEC has evolved, we characterized a diverse collection of strains by multilocus sequence typing (MLST) and performed restriction fragment length polymorphism (RFLP) analysis of three virulence genes (eae, bfpA, and perA) to assess allelic variation. Among 129 strains representing 20 O-serogroups, 21 clonal genotypes were identified using MLST. RFLP analysis resolved nine eae, nine bfpA, and four perA alleles. Each bfpA allele was associated with only one perA allele class, suggesting that recombination has not played a large role in shuffling the bfpA and perA loci between separate EAF plasmids. The distribution of eae alleles among typical EPEC strains is more concordant with the clonal relationships than the distribution of the EAF plasmid types. These results provide further support for the hypothesis that the EPEC pathotype has evolved multiple times within E. coli through separate acquisitions of the LEE island and EAF plasmid.
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Affiliation(s)
- David W Lacher
- National Food Safety & Toxicology Center, Michigan State University, East Lansing, MI 48824, USA
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Alikhani MY, Mirsalehian A, Aslani MM. Detection of typical and atypical enteropathogenic Escherichia coli (EPEC) in Iranian children with and without diarrhoea. J Med Microbiol 2006; 55:1159-1163. [PMID: 16914644 DOI: 10.1099/jmm.0.46539-0] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The present study was performed to investigate the contribution of typical and atypical enteropathogenic Escherichia coli (EPEC) as a cause of infectious diarrhoea among children less than 10 years old in Iran. During the summer months, 247 specimens from children with diarrhoea and 1108 from asymptomatic children were analysed for the presence of EPEC and other bacterial pathogens. Potential enteric pathogens were identified in 140 cases of children with diarrhoea (56.7%). EPEC was the most frequently identified agent (111 cases), followed by Shiga toxin-producing E. coli (13), Shigella (9), Salmonella (6) and Aeromonas sp. (1). EPEC isolates were examined for the presence of eaeA, bfpA and stx genes by PCR. EPEC isolates were classified as typical (eaeA+ bfpA+) or atypical (eaeA+ bfpA-). Typical EPEC was diagnosed in 35 cases (11.8%), compared with 8 (0.4%) in the asymptomatic group (P<0.05). Atypical EPEC strains were isolated from 23 cases (9.3%), compared with 13 (1.2%) of the healthy control group (P<0.05). In conclusion, the data suggest that typical and atypical EPEC are an important cause of diarrhoea in Iranian children.
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Affiliation(s)
- M Yousef Alikhani
- Department of Microbiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
- Department of Microbiology, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Akbar Mirsalehian
- Department of Microbiology, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - M Mehdi Aslani
- Department of Microbiology, Institute Pasteur of Iran, 69 Pasteur Avenue, Tehran, Iran
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14
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Lacher DW, Steinsland H, Whittam TS. Allelic subtyping of the intimin locus (eae) of pathogenic Escherichia coli by fluorescent RFLP. FEMS Microbiol Lett 2006; 261:80-7. [PMID: 16842363 DOI: 10.1111/j.1574-6968.2006.00328.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Intimin is a highly polymorphic protein encoded by the eae gene and plays a crucial role in the attaching-effacing phenotype of diarrheagenic Escherichia coli and related pathogens. We have developed a method to quickly and accurately uncover allelic variation at the eae locus through the use of fluorescent RFLP (fRFLP). Application of fRFLP to 151 eae-positive strains (including the newly described Escherichia albertii) revealed 26 different fRFLP types that correspond to 20 of the 28 previously described eae alleles. Two sequence variants of the gamma, iota, kappa, and zeta alleles and three variants of epsilon were also observed. In addition to being reliable and accurate, the method can be easily adapted to accommodate new eae allelic sequences, as they become known.
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Affiliation(s)
- David W Lacher
- Microbial Evolution Laboratory, National Food Safety and Toxicology Center, Michigan State University, East Lansing, MI 48824, USA
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15
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Whale AD, Garmendia J, Gomes TA, Frankel G. A novel category of enteropathogenic Escherichia coli simultaneously utilizes the Nck and TccP pathways to induce actin remodelling. Cell Microbiol 2006; 8:999-1008. [PMID: 16681840 DOI: 10.1111/j.1462-5822.2006.00682.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Enterohaemorrhagic Escherichia coli (EHEC) and enteropathogenic E. coli (EPEC) induce drastic reorganization of the microfilament cytoskeleton. EHEC and EPEC translocate Tir (translocated intimin receptor) which, once inserted into the host plasma membrane, binds the bacterial outer membrane adhesin intimin. Tir(EPEC) then becomes tyrosine phosphorylated facilitating the recruitment and site-specific binding of the eukaryotic adaptor Nck, which in turn binds and activates the Wiskott-Aldrich syndrome protein (N-WASP), leading to actin-related protein 2/3 (Arp2/3) complex-mediated actin polymerization. In contrast, Tir(EHEC) has no Nck binding site; instead, EHEC utilizes the translocated effector TccP (Tir-cytoskeleton coupling protein) to bind and activate N-WASP. Here we report a novel class of EPEC that translocates both TccP and Tir(EPEC)-like effector molecules. Consistent with these characteristics, we show that both the Tir-Nck and Tir:TccP actin remodelling pathways function simultaneously during infection, making this a novel and versatile EPEC category.
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Affiliation(s)
- Andrew D Whale
- Division of Molecular and Cellular Biology, Imperial College London, London, UK
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16
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Campos LC, Franzolin MR, Trabulsi LR. Diarrheagenic Escherichia coli categories among the traditional enteropathogenic E. coli O serogroups--a review. Mem Inst Oswaldo Cruz 2004; 99:545-52. [PMID: 15558161 DOI: 10.1590/s0074-02762004000600001] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The so called enteropathogenic Escherichia coli (EPEC) O serogroups include typical and atypical EPEC, enterohaemorrragic E. coli, enterotoxigenic E. coli, and enteroaggregative E. coli. The aim of this article is to review the composition of each O serogroup and the major serotypes, clones, and additional virulence characteristics of each of these diarrheagenic categories. Their adherence patterns and genetic relationships are also presented. The review is based on the study of 805 strains of serogroups O26, O55, O86, O111, O114, O119, O125, O126, O1127, O128, and O142 most of which isolated in Sao Paulo from children with diarrhea between 1970 and 1990. Since some O serogroups include more than one diarrheagenic category O serogrouping only should be abandoned as a diagnostic method. However serotyping is a reliable method for those serotypes that correspond to clones.
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Affiliation(s)
- Leila C Campos
- Departamento de Bacteriologia, Instituto Oswaldo Cruz-Fiocruz, Brasil 4365, 21045-900 Rio de Janeiro, RJ, Brazil.
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17
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Rodrigues J, Thomazini CM, Morelli A, de Batista GCM. Reduced etiological role for enteropathogenic Escherichia coli in cases of diarrhea in Brazilian infants. J Clin Microbiol 2004; 42:398-400. [PMID: 14715789 PMCID: PMC321700 DOI: 10.1128/jcm.42.1.398-400.2004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Previously common in Brazil, enteropathogenic Escherichia coli (EPEC) strains of serogroups O55, O111, and O119 are now rare, while enteroadherent strains other than EPEC, belonging to serogroups such as O125, were prevalent among 126 diarrheic infants less than 1 year old who were surveyed. None of these strains had the EPEC bundle-forming pilus (bfpA) gene.
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Affiliation(s)
- Josias Rodrigues
- Departamento de Microbiologia e Imunologia, Instituto de Biociências da UNESP em Botucatu, São Paulo, Brazil.
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18
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Regua-Mangia AH, Gomes TAT, Vieira MAM, Andrade JRC, Irino K, Teixeira LM. Frequency and characteristics of diarrhoeagenic Escherichia coli strains isolated from children with and without diarrhoea in Rio de Janeiro, Brazil. J Infect 2004; 48:161-7. [PMID: 14720492 DOI: 10.1016/s0163-4453(03)00138-5] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The frequency of diarrhoeagenic Escherichia coli (DEC) strains was investigated in 253 children up to 3 years old, with (patient group, PG, 199 children) and without (control group, CG, 54 children) diarrhoea, living in Rio de Janeiro, Brazil. DEC strains were detected in 70 (27.6%) children, including 54 (27.1%) with diarrhoea and 16 (29.6%) without diarrhoea. Enteroaggregative E. coli (EAEC) was the most frequent DEC category, accounting for 14.6% of the isolates in the PG and for 11.1% in the CG. E. coli strains carrying enteropathogenic E. coli (EPEC) virulence markers showed higher incidence in the CG (12.9%) than in the PG (8.0%). E. coli strains belonging to non-classical EPEC groups that carried eae only or eae and bfpA, designated as attaching-effacing E. coli (AEEC) were the most frequent (79.1%). Simultaneous presence of multiple EPEC virulence factors (EAF/eae/bfpA) were only detected among strains isolated from the PG. Enterotoxigenic E. coli (ETEC) strains were isolated from 5.5% of the children in the CG and from 3.5% of those in the PG. Most of the ETEC isolates were LT-probe positive (70%) and none carried both LT-I and ST-I probe sequences. One enteroinvasive E. coli (EIEC) strain was recovered from a child with diarrhoea. No stx-probe positive E. coli strains were detected. Overall, DEC strains were not found to be significantly associated with diarrhoea (p>0.05). However, the higher incidence of EAEC, the most frequent DEC category, among children with diarrhoea, suggests a potential role of EAEC as an important enteric pathogen in the community investigated.
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Affiliation(s)
- A H Regua-Mangia
- Fundação Oswaldo Cruz, Escola Nacional de Saúde Pública, Laboratório de Epidemiologia Molecular, Rua Leopoldo Bulhões, 1480-60 andar, Rio de Janeiro, RJ, Brazil.
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19
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Vaz TMI, Irino K, Kato MAMF, Dias AMG, Gomes TAT, Medeiros MIC, Rocha MMM, Guth BEC. Virulence properties and characteristics of Shiga toxin-producing Escherichia coli in São Paulo, Brazil, from 1976 through 1999. J Clin Microbiol 2004; 42:903-5. [PMID: 14766885 PMCID: PMC344473 DOI: 10.1128/jcm.42.2.903-905.2004] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2003] [Revised: 09/22/2003] [Accepted: 11/04/2003] [Indexed: 11/20/2022] Open
Abstract
Twenty-nine Shiga toxin-producing Escherichia coli (STEC) strains were identified in a collection of 2,607 isolates from patients with diarrhea in São Paulo, Brazil, from 1976 to 1999. The STEC strains belonged mainly to serotypes O111:HNM (HNM, nonmotile) (13 of 29 [44.8%]), O111:H8 (7 of 29 [24%]), and O26:H11 (4 of 29 [13.8%]); stx(1) eae (26 of 29 [89.6%]), in combination with either enterohemorrhagic E. coli hlyA (11 of 26 [42%]) or astA (24 of 26 [92.3%]), prevailed. The O111 STEC strains were distinguished by their inability to decarboxylate lysine. The predominance of STEC O111 and O26 since the late 1970s and the identification of STEC serotypes O55:H19, O93:H19, and O118:H16 in association with human infections in Brazil are described for the first time.
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Affiliation(s)
- T M I Vaz
- Instituto Adolfo Lutz. Universidade Federal de São Paulo-Escola Paulista de Medicina, São Paulo Instituto Adolfo Lutz, Ribeirão Preto
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20
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Jores J, Zehmke K, Eichberg J, Rumer L, Wieler LH. Description of a novel intimin variant (type zeta) in the bovine O84:NM verotoxin-producing Escherichia coli strain 537/89 and the diagnostic value of intimin typing. Exp Biol Med (Maywood) 2003; 228:370-6. [PMID: 12671181 DOI: 10.1177/153537020322800407] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Infections with verotoxin-producing Escherichia coli (VTEC) has resulted in increasing numbers of human illnesses annually. These illnesses usually result from the ability of VTEC to cause the attaching and effacing lesions (AE lesion). The AE phenotype is encoded by the locus of enterocyte effacement (LEE) pathogenicity island. A key adhesion factor involved is the outer membrane protein intimin, encoded by the eae gene within the LEE. Intimin types alpha, beta, gamma, delta, and epsilon have been described previously. Each intimin represents distinct phylogenetic lineages of LEE-positive strains. A new intimin type zeta was identified in a VTEC strain of the serotype O84:NM (nonmotile) that was isolated from a calf with diarrhea. zeta intimin showed the highest similarity (88%) of its amino acid sequence to the alpha intimin. For diagnostic purposes, we established a polymerase chain reaction (PCR) method for diagnosis of the key virulence traits of VTEC (i.e., verotoxins and intimins). This method also distinguishes between the toxins (VT1 and VT2) and the six intimin types. By applying the PCR method, intimin zeta in strains of other VTEC serotypes O84:H2, O92:NM, O119:H25, and O150:NM was identified. Because the intimin types represent distinctive phylogenetic E. coli lineages, application of the intimin subtyping PCR offers significant benefits. These include improving diagnosis of VTEC infection and increasing the understanding of evolution of attaching and effacing VTEC and other LEE-positive bacteria.
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Affiliation(s)
- Joerg Jores
- Institut für Mikrobiologie und Tierseuchen, Freie Universität Berlin, 10115 Berlin, Germany.
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21
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Guth BEC, Ramos SRTS, Cerqueira AMF, Andrade JRC, Gomes TAT. Phenotypic and genotypic characteristics of shiga toxin-producing Escherichia coli strains isolated from children in São Paulo, Brazil. Mem Inst Oswaldo Cruz 2002; 97:1085-9. [PMID: 12563470 DOI: 10.1590/s0074-02762002000800003] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The biochemical and serological characteristics, virulence properties, and genetic relatedness of Shiga toxin-producing Escherichia coli (STEC) strains isolated in S o Paulo, from April 1989 through March 1990, were determined. This is also the first report on clinic findings of human STEC infections in Brazil. The only three STEC strains identified in that period were lysine decarboxylase negative, belonged to serotype O111ac: non-motile, were Stx1 producers, carried the eae and astA genes, and 2 of them also presented the EHEC-hly sequence. The children carrying STEC were all boys, with less than two years old, and had no previous history of hospitalization. None of them presented blood in stools. Vomiting, cough and coryza were the most common clinical manifestations observed. Although the STEC strains were isolated during summer months, and presented similar phenotypic and genotypic characteristics, carbohydrate fermentation patterns and PFGE analysis suggested that these diarrheal episodes were not caused by a single clone.
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Affiliation(s)
- Beatriz E C Guth
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, Escola Paulista de Medicina, 04023-062 São Paulo, SP, Brasil.
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22
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Gismero-Ordoñez J, Dall'Agnol M, Trabulsi LR, Girón JA. Expression of the bundle-forming pilus by enteropathogenic Escherichia coli strains of heterologous serotypes. J Clin Microbiol 2002; 40:2291-6. [PMID: 12037114 PMCID: PMC130815 DOI: 10.1128/jcm.40.6.2291-2296.2002] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2001] [Revised: 01/27/2002] [Accepted: 03/01/2002] [Indexed: 11/20/2022] Open
Abstract
The production of the bundle-forming pilus subunit BfpA was investigated in 44 enteropathogenic Escherichia coli (EPEC) diarrheal isolates after growth on several conventional bacteriological media. In all, the use of brucella agar supplemented with 4.5 mM sodium bisulfite resulted in a higher detection of BfpA-producing EPEC.
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Affiliation(s)
- Juana Gismero-Ordoñez
- Departamento de Microbiologia, Universidade de São Paulo, and Instituto Butantã, São Paulo, Brazil
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23
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Abstract
Typical and atypical enteropathogenic Escherichia coli (EPEC) strains differ in several characteristics. Typical EPEC, a leading cause of infantile diarrhea in developing countries, is rare in industrialized countries, where atypical EPEC seems to be a more important cause of diarrhea. For typical EPEC, the only reservoir is humans; for atypical EPEC, both animals and humans can be reservoirs. Typical and atypical EPEC also differ in genetic characteristics, serotypes, and virulence properties. Atypical EPEC is more closely related to Shiga toxin-producing E. coli (STEC), and like STEC these strains appear to be emerging pathogens.
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Affiliation(s)
- Luiz R Trabulsi
- Laboratório Especial de Microbiologia, prédio novo, 2nd andar, Instituto Butantan, Av. Vital Brasil, 1500 São Paulo, Brazil, CEP:05503-900.
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24
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Irino K, Vaz TMI, Kato MAMF, Naves ZVF, Lara RR, Marco MEC, Rocha MMM, Moreira TP, Gomes TAT, Guth BEC. O157:H7 Shiga toxin-producing Escherichia coli strains associated with sporadic cases of diarrhea in São Paulo, Brazil. Emerg Infect Dis 2002; 8:446-7. [PMID: 11971785 PMCID: PMC2730246 DOI: 10.3201/eid0804.010490] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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25
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Irino K, Dias AM, Kano E, Vaz TM, Kato MA, Gonçalves CR, Vieira MA, Gomes TA. Metabolism of phenylpropionic acid in enteropathogenic Escherichia coli belonging to serogroup O111 and its application for diagnosis. FEMS Microbiol Lett 2001; 204:105-10. [PMID: 11682187 DOI: 10.1111/j.1574-6968.2001.tb10871.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
We evaluated a biochemical assay based on the ability to metabolise beta-phenylpropionic acid (PPA) as a diagnostic aid in the identification of typical enteropathogenic Escherichia coli (EPEC) strains. A total of 1061 E. coli strains of serogroups O55, O111, and O119 were initially characterised regarding their H types (serotypes) and the presence of EPEC DNA sequences, eae, EAF, and bfpA. In case of the serogroup O111 strains, 84.6% carried the typical EPEC markers, and the great majority of those (98.1%) were PPA-positive. In contrast, only 0.9% of the serogroups O55 and O119 strains carrying the typical EPEC markers (53.6% and 75.4%, respectively) were PPA-positive. We conclude that the PPA test is a useful method to detect typical EPEC strains only among strains of the O111 serogroup.
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Affiliation(s)
- K Irino
- Seção de Bacteriologia, Institute Adolpho Lutz, Av Dr Arnaldo, 351, CEP 01246-902, São Paulo, Brazil.
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26
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Okeke IN, Borneman JA, Shin S, Mellies JL, Quinn LE, Kaper JB. Comparative sequence analysis of the plasmid-encoded regulator of enteropathogenic Escherichia coli Strains. Infect Immun 2001; 69:5553-64. [PMID: 11500429 PMCID: PMC98669 DOI: 10.1128/iai.69.9.5553-5564.2001] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Enteropathogenic Escherichia coli (EPEC) strains that carry the EPEC adherence factor (EAF) plasmid were screened for the presence of different EAF sequences, including those of the plasmid-encoded regulator (per). Considerable variation in gene content of EAF plasmids from different strains was seen. However, bfpA, the gene encoding the structural subunit for the bundle-forming pilus, bundlin, and per genes were found in 96.8% of strains. Sequence analysis of the per operon and its promoter region from 15 representative strains revealed that it is highly conserved. Most of the variation occurs in the 5' two-thirds of the perA gene. In contrast, the C-terminal portion of the predicted PerA protein that contains the DNA-binding helix-turn-helix motif is 100% conserved in all strains that possess a full-length gene. In a minority of strains including the O119:H2 and canine isolates and in a subset of O128:H2 and O142:H6 strains, frameshift mutations in perA leading to premature truncation and consequent inactivation of the gene were identified. Cloned perA, -B, and -C genes from these strains, unlike those from strains with a functional operon, failed to activate the LEE1 operon and bfpA transcriptional fusions or to complement a per mutant in reference strain E2348/69. Furthermore, O119, O128, and canine strains that carry inactive per operons were deficient in virulence protein expression. The context in which the perABC operon occurs on the EAF plasmid varies. The sequence upstream of the per promoter region in EPEC reference strains E2348/69 and B171-8 was present in strains belonging to most serogroups. In a subset of O119:H2, O128:H2, and O142:H6 strains and in the canine isolate, this sequence was replaced by an IS1294-homologous sequence.
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Affiliation(s)
- I N Okeke
- Department of Microbiology and Immunology and Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
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27
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Ghilardi AC, Gomes TA, Trabulsi LR. Production of cytolethal distending toxin and other virulence characteristics of Escherichia coli strains of serogroup O86. Mem Inst Oswaldo Cruz 2001; 96:703-8. [PMID: 11500775 DOI: 10.1590/s0074-02762001000500022] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Genetic and phenotypic virulence markers of different categories of diarrhoeagenic Escherichia coli were investigated in 106 strains of enteropathogenic E. coli (EPEC) serogroup O86. The most frequent serotype found was O86:H34 (86%). Strains of this serotype and the non motile ones behaved as EPEC i.e., carried eae, bfpA and EAF DNA sequences and presented localised adherence to HeLa cells. Serotypes O86:H2, O86:H6, O86:H10, O86:H18, O86:H27 and O86:H non determined, belonged to other categories. The majority of the strains of serotype O86:H34 and non motile strains produced cytolethal-distending toxin (CDT). The ribotyping analysis showed a correlation among ribotypes, virulence markers and serotypes, thus suggesting that CDT production might be a property associated with a universal clone represented by the O86:H34 serotype.
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Affiliation(s)
- A C Ghilardi
- Seção de Bacteriologia, Instituto Adolfo Lutz, 01246-902 São Paulo, SP, Brasil.
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28
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Paiva de Sousa C, Dubreuil JD. Distribution and expression of the astA gene (EAST1 toxin) in Escherichia coli and Salmonella. Int J Med Microbiol 2001; 291:15-20. [PMID: 11403406 DOI: 10.1078/1438-4221-00097] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The distribution and expression of the astA gene (EAST1 toxin) among 358 strains of Enterobacteriaceae were studied. The gene was found in 32.6% and 11.9% of Escherichia coli and Salmonella strains, respectively. The majority of E. coli EAST1-positive strains were found among EHEC (88.0%), EAggEC (86.6%), and A-EPEC (58.3%). The gene was present in 16.6% of E. coli strains without known virulence genes. There was no significant variation among the different serotypes of E. coli tested regarding the presence of the gene. For EPEC, 13.7% of the tested strains were astA-positive. Among atypical EPEC (eae+, bfp-, EAF-) and (eae+, bfp+, EAF-) 46.2 and 72.7%, respectively, were positive. The majority of the A-EPEC (87%) and EaggEC (83%) strains expressed the EAST-1 toxin as judged from Ussing chamber experiments. Of 32 EIEC strains studied, 2 possessed and expressed the gene as determined in Ussing chamber experiments. Among the Salmonella strains studied, five strains isolated from food were positive for astA and one strain of S. agona showed biological activity in Ussing chamber experiments.
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Affiliation(s)
- C Paiva de Sousa
- Departamento de Nurtição, Universidada Federale da Paraíba, João Pessoa, Brasil
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29
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Mellies JL, Navarro-Garcia F, Okeke I, Frederickson J, Nataro JP, Kaper JB. espC pathogenicity island of enteropathogenic Escherichia coli encodes an enterotoxin. Infect Immun 2001; 69:315-24. [PMID: 11119520 PMCID: PMC97886 DOI: 10.1128/iai.69.1.315-324.2001] [Citation(s) in RCA: 119] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
At least five proteins are secreted extracellularly by enteropathogenic Escherichia coli (EPEC), a leading cause of infant diarrhea in developing countries. However only one, EspC, is known to be secreted independently of the type III secretion apparatus encoded by genes located within the 35.6-kb locus of enterocyte effacement pathogenicity island. EspC is a member of the autotransporter family of proteins, and the secreted portion of the molecule is 110 kDa. Here we determine that the espC gene is located within a second EPEC pathogenicity island at 60 min on the chromosome of E. coli. We also show that EspC is an enterotoxin, indicated by rises in short-circuit current and potential difference in rat jejunal tissue mounted in Ussing chambers. In addition, preincubation with antiserum against the homologous Pet enterotoxin of enteroaggregative E. coli eliminated EspC enterotoxin activity. Like the EAF plasmid, the espC pathogenicity island was found only in a subset of EPEC, suggesting that EspC may play a role as an accessory virulence factor in some but not all EPEC strains.
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Affiliation(s)
- J L Mellies
- Biology Department, Reed College, Portland, Oregon 97202, USA
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30
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Pupo GM, Lan R, Reeves PR, Baverstock PR. Population genetics of Escherichia coli in a natural population of native Australian rats. Environ Microbiol 2000; 2:594-610. [PMID: 11214793 DOI: 10.1046/j.1462-2920.2000.00142.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Escherichia coli, a normal inhabitant of the intestinal tract of mammals and birds, is a diverse species. Most studies on E. coli populations involve organisms from humans or human-associated animals. In this study, we undertook a survey of E. coli from native Australian mammals, predominantly Rattus tunneyi, living in a relatively pristine environment in the Bundjalung National Park. The genetic diversity was assessed and compared by multilocus enzyme electrophoresis (MLEE), sequence analysis of the mdh (malate dehydrogenase) gene and biotyping using seven sugars. Ninety-nine electrophoretic types were identified from the 242 isolates analysed by MLEE and 15 sequences from the mdh genes sequenced from 21 representative strains. The Bundjalung isolates extend the diversity represented by the E. coli reference (ECOR) set, with new MLEE alleles found in six out of 10 loci. Many of the Bundjalung isolates fell into a discrete group in MLEE. Other Bundjalung strains fell into the recognized E. coli ECOR set groups, but tended to be at the base of both the MLEE and mdh gene trees, implying that these strains are derived independently from ancestral forms of the ECOR groups and that ECOR strains represent only a subset of E. coli adapted to humans and human-associated animals. Linkage disequilibrium analysis showed that the Bundjalung population has an 'epidemic' population structure. The Bundjalung isolates were able to utilize more sugars than the ECOR strains, suggesting that diet plays a prominent role in adaptation of E. coli.
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Affiliation(s)
- G M Pupo
- Department of Microbiology, The University of Sydney, NSW, Australia
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31
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Girão DM, Bando SY, Girão VBDC, Moreira-Filho CA, Fracalanzza SEL, Trabulsi LR, Monteiro-Neto V. Characterization of typical and atypical enteropathogenic Escherichia coli (EPEC) strains of the classical O55 serogroup by RAPD analysis. ACTA ACUST UNITED AC 1999. [DOI: 10.1590/s0001-37141999000400013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
Abstract
The genetic diversity of 41 typical and atypical enteropathogenic Escherichia coli (EPEC) strains of the serogroup O55 was analyzed by using the random amplified polymorphic DNA (RAPD) method. All typical EPEC O55 strains were grouped in two clusters (A and C) and belonged to the serotype O55:H6, while cluster B included all atypical strains, which were of the serotype O55:H7. The three groups also included non-motile strains. RAPD may be a useful method for epidemiological studies on E. coli O55 infection.
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Muniesa M, Lucena F, Jofre J. Comparative survival of free shiga toxin 2-encoding phages and Escherichia coli strains outside the gut. Appl Environ Microbiol 1999; 65:5615-8. [PMID: 10584029 PMCID: PMC91769 DOI: 10.1128/aem.65.12.5615-5618.1999] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The behavior outside the gut of seeded Escherichia coli O157:H7, naturally occurring E. coli, somatic coliphages, bacteriophages infecting O157:H7, and Shiga toxin 2 (Stx2)-encoding bacteriophages was studied to determine whether the last persist in the environment more successfully than their host bacteria. The ratios between the numbers of E. coli and those of the different bacteriophages were clearly lower in river water than in sewage of the area, whereas the ratios between the numbers of the different phages were similar. In addition, the numbers of bacteria decreased between 2 and 3 log units in in situ survival experiments performed in river water, whereas the numbers of phages decreased between 1 and 2 log units. Chlorination and pasteurization treatments that reduced by approximately 4 log units the numbers of bacteria reduced by less than 1 log unit the numbers of bacteriophages. Thus, it can be concluded that Stx2-encoding phages persist longer than their host bacteria in the water environment and are more resistant than their host bacteria to chlorination and heat treatment.
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Affiliation(s)
- M Muniesa
- Department de Microbiologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
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Bortolini MR, Trabulsi LR, Keller R, Frankel G, Sperandio V. Lack of expression of bundle-forming pili in some clinical isolates of enteropathogenic Escherichia coli (EPEC) is due to a conserved large deletion in the bfp operon. FEMS Microbiol Lett 1999; 179:169-74. [PMID: 10481102 DOI: 10.1111/j.1574-6968.1999.tb08723.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Enteropathogenic Escherichia coli (EPEC) produces a plasmid-encoded type IV pilus, called the bundle-forming pilus (BFP), involved in the formation of the localized adhesion onto epithelial cells. In this study, we demonstrate that clinical isolates of serotypes O128ab:H2 and O119:H2 contain a ca. 13-kb deletion in the bfp operon, resulting in a lack of expression of these pili. An IS sequence with homology to the IS66 of Agrobacterium tumefaciens replaced the deleted bfp genes. These results suggest that the bfp operon was deleted through a transpositional event and that other adherence factors may mediate attachment of these bacteria to the host cells.
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Affiliation(s)
- M R Bortolini
- Instituto de Ciências Biomédicas, Departamento de Microbiologia, Universidade de São Paulo, Av. Prof Lineu Prestes, 1374 CEP:05389-970, São Paulo, Brazil
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Gomes TA, Vieira MA, Abe CM, Rodrigues D, Griffin PM, Ramos SR. Adherence patterns and adherence-related DNA sequences in Escherichia coli isolates from children with and without diarrhea in São Paulo city, Brazil. J Clin Microbiol 1998; 36:3609-13. [PMID: 9817882 PMCID: PMC105249 DOI: 10.1128/jcm.36.12.3609-3613.1998] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The correlation between various adherence patterns and adherence-related DNA sequences in Escherichia coli isolates from 1- to 4-year-old children with and without diarrhea in São Paulo, Brazil, was evaluated. A total of 1,801 isolates obtained from 200 patients and 200 age-matched controls were studied. The adherence patterns found were classified as diffuse, aggregative, aggregative in a 6-h assay, aggregative predominantly in coverslips, localized, localized-like, and noncharacteristic. In general, the DNA sequences used as probes showed excellent specificities (>93%), but their sensitivities varied. Thus, the results of bioassays and assays with DNA probes normally used to search for adherent E. coli did not correlate well, and the best method for the identification of these organisms in the clinical research setting remains controversial. Isolates presenting diffuse adherence or hybridizing with the related daaC probe, or both, were by far the most frequent in patients (31.5, 26.0, and 23.0%, respectively), followed by isolates presenting aggregative adherence or hybridizing with the related EAEC probe, or both (21.5, 13.0, and 10.5%, respectively). None of the different combinations of adherence patterns and adherence-related DNA sequences found were associated with acute diarrhea.
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Affiliation(s)
- T A Gomes
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, Escola Paulista de Medicina, São Paulo, S.P., Brazil, CEP 04023-062.
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Ferreira RC, Costa SO, Ferreira LC, Trabulsi LR. Penicillin-binding proteins of pathogenic Escherichia coli strains. FEMS Microbiol Lett 1998; 168:313-7. [PMID: 9835043 DOI: 10.1111/j.1574-6968.1998.tb13289.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The penicillin-binding proteins of 11 pathogenic Escherichia coli strains, including enteropathogenic, enterotoxigenic, enteroinvasive, enteroaggregative, and enterohemorrhagic E. coli, were detected in gels following the labeling of isolated cell envelopes with [3H]benzylpenicillin. The electrophoretic profiles, sensitivities to and morphological changes induced by beta-lactam antibiotics showed that the penicillin-binding proteins of most pathogenic E. coli possess structural and physiological functions similar to those of E. coli K12.
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Affiliation(s)
- R C Ferreira
- Departamento de Microbiologia, Universidade de São Paulo, Brazil.
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36
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Gyles C, Johnson R, Gao A, Ziebell K, Pierard D, Aleksic S, Boerlin P. Association of enterohemorrhagic Escherichia coli hemolysin with serotypes of shiga-like-toxin-producing Escherichia coli of human and bovine origins. Appl Environ Microbiol 1998; 64:4134-41. [PMID: 9797257 PMCID: PMC106619 DOI: 10.1128/aem.64.11.4134-4141.1998] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/1998] [Accepted: 08/12/1998] [Indexed: 11/20/2022] Open
Abstract
In this study we investigated whether the enterohemorrhagic Escherichia coli (EHEC) hemolysin gene ehxA could be used as an indicator of pathogenicity in Shiga-like-toxin-producing Escherichia coli (SLTEC) isolates. The isolates in a collection of 770 SLTEC strains of human and bovine origins were assigned to group 1 (230 human and 138 bovine SLTEC isolates belonging to serotypes frequently implicated in human disease), group 2 (85 human and 183 bovine isolates belonging to serotypes less frequently implicated in disease), and group 3 (134 bovine isolates belonging to serotypes not implicated in disease). PCR amplification was used to examine all of the SLTEC isolates for the presence of ehxA and the virulence-associated genes eae, slt-I, and slt-II. The percentages of human isolates in groups 1 and 2 that were positive for ehxA were 89 and 46%, respectively, and the percentages of bovine isolates in groups 1 to 3 that were positive for ehxA were 89, 51, and 52%, respectively. The percentages of human isolates in groups 1 and 2 that were positive for eae were 92 and 27%, respectively, and the percentages of bovine isolates in groups 1 to 3 that were positive for eae were 78, 15, and 19%, respectively. The frequencies of both ehxA and eae were significantly higher for group 1 isolates than for group 2 isolates. The presence of the ehxA gene was associated with serotype, as was the presence of the eae gene. Some serotypes, such as O117:H4, lacked both eae and ehxA and have been associated with severe disease, but only infrequently. The slt-I genes were more frequent in group 1 isolates than in group 2 isolates, and the slt-II genes were more frequent in group 2 isolates than in group 1 isolates. In a second experiment we determined the occurrence of the ehxA and slt genes in E. coli isolated from bovine feces. Fecal samples from 175 animals were streaked onto washed sheep erythrocyte agar plates. Eight E. coli-like colonies representing all of the morphological types were transferred to MacConkey agar. A total of 1, 080 E. coli isolates were examined, and the ehxA gene was detected in 12 independent strains, only 3 of which were positive for slt. We concluded that the ehxA gene was less correlated with virulence than the eae gene was and that EHEC hemolysin alone has limited value for screening bovine feces for pathogenic SLTEC because of presence of the ehxA gene in bovine isolates that are not SLTEC.
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Affiliation(s)
- C Gyles
- Department of Pathobiology, University of Guelph, Guelph, Ontario, Canada.
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Sperandio V, Kaper JB, Bortolini MR, Neves BC, Keller R, Trabulsi LR. Characterization of the locus of enterocyte effacement (LEE) in different enteropathogenic Escherichia coli (EPEC) and Shiga-toxin producing Escherichia coli (STEC) serotypes. FEMS Microbiol Lett 1998; 164:133-9. [PMID: 9675859 DOI: 10.1111/j.1574-6968.1998.tb13078.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
All proteins involved in the attachment and effacement lesion produced by enteropathogenic Escherichia coli (EPEC) and Shiga-toxin producing E. coli (STEC) are encoded by the locus of enterocyte effacement (LEE). We studied the presence and insertion site of the LEE in different EPEC and STEC strains. In serotypes O119:H6/H-, O55:H6, O55:H7, O142:H6, O111ac:H9/H-, O111ab:H9/H- LEE is inserted downstream of selC as previously described for EPEC O127:H6 and STEC O157:H7. In serotypes O111ac:H8/H- and O26:H11/H- the LEE is inserted in pheU as previously described for STEC O26:H-. However in EPEC from serotype O111ab:H25 the LEE is not inserted in either site suggesting a third insertion site in the K12 chromosome. We also cloned fragments of 2.3 kb and 1.0 kb from the right and left hand sides of the LEE of a O111ac:H- strain and identified additional insertion sequences on these LEE fragments, suggesting that the LEE may be larger and may have undergone more recombination events in these serotypes.
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Affiliation(s)
- V Sperandio
- Departamento de Microbiologia, Universidade de Sao Paulo, Brazil.
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Hicks S, Frankel G, Kaper JB, Dougan G, Phillips AD. Role of intimin and bundle-forming pili in enteropathogenic Escherichia coli adhesion to pediatric intestinal tissue in vitro. Infect Immun 1998; 66:1570-8. [PMID: 9529083 PMCID: PMC108090 DOI: 10.1128/iai.66.4.1570-1578.1998] [Citation(s) in RCA: 160] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Attaching and effacing (A/E) lesion formation is central to enteropathogenic Escherichia coli (EPEC) pathogenesis. In vitro experiments with human epithelial cell lines have implicated virulence plasmid-encoded bundle-forming pili (BFP) in initial binding and intimin in intimate attachment and A/E lesion formation. This study investigated the role of BFP and intimin in EPEC interactions with pediatric small intestinal biopsy tissue in in vitro organ culture. Organ culture infections (2 to 8 h) were performed with E2348/69 (a wild-type EPEC O127:H6 clinical isolate) and E2348/69 derivatives including CVD206 (eae deficient), CVD206(pCVD438) (eae-complemented CVD206), CVD206(pCVD438/01) (expressing intimin, which is nonfunctional due to a single amino acid substitution), JPN15 (spontaneous EPEC adherence factor virulence plasmid-cured E2348/69), and 31-6-1(1) (E2348/69 with a TnphoA insertion inactivation mutation in the virulence plasmid-encoded bfpA gene). Scanning and transmission electron microscopy revealed that after 8 h E2348/69 and CVD206 (pCVD438) (both Int+ BFP+) adhered to all specimens, causing A/E lesions with surrounding microvillous elongation. JPN15 and 31-6-1(1) (both Int+ BFP-) adhered and caused A/E lesions although bacteria adhered in "flat," two-dimensional groups. CVD206 and CVD206(pCVD438/01) (both Int- BFP+) did not adhere to any sample, and no pathological tissue changes were seen. Thus, in human intestinal organ culture, BFP do not appear to be involved in the initial stages of EPEC nonintimate adhesion but are implicated in the formation of complex, three-dimensional colonies via bacterium-bacterium interactions. Intimin appears to play an essential role in establishing colonization of EPEC on pediatric small intestinal tissue.
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Affiliation(s)
- S Hicks
- University Department of Paediatric Gastroenterology, Royal Free Hospital, London, United Kingdom
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Adu-Bobie J, Frankel G, Bain C, Goncalves AG, Trabulsi LR, Douce G, Knutton S, Dougan G. Detection of intimins alpha, beta, gamma, and delta, four intimin derivatives expressed by attaching and effacing microbial pathogens. J Clin Microbiol 1998; 36:662-8. [PMID: 9508292 PMCID: PMC104605 DOI: 10.1128/jcm.36.3.662-668.1998] [Citation(s) in RCA: 229] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/1997] [Accepted: 11/19/1997] [Indexed: 02/06/2023] Open
Abstract
Intimins are outer membrane proteins expressed by enteric bacterial pathogens capable of inducing intestinal attachment-and-effacement lesions. A eukaryotic cell-binding domain is located within a 280-amino-acid (Int280) carboxy terminus of intimin polypeptides. Polyclonal antiserum was raised against Int280 from enteropathogenic Escherichia coli (EPEC) serotypes O127:H6 and O114:H2 (anti-Int280-H6 and anti-Int280-H2, respectively), and Western blot analysis was used to explore the immunological relationship between the intimin polypeptides expressed by different clinical EPEC and enterohemorrhagic E. coli (EHEC) isolates, a rabbit diarrheagenic E. coli strain (RDEC-1), and Citrobacter rodentium. Anti-Int280-H6 serum reacted strongly with some EPEC serotypes, whereas anti-Int280-H2 serum reacted strongly with strains belonging to different EPEC and EHEC serotypes, RDEC-1, and C. rodentium. These observations were confirmed by using purified Int280 in an enzyme-linked immunosorbent assay and by immunogold and immunofluorescence labelling of whole bacterial cells. Some bacterial strains were recognized poorly by either antiserum (e.g., EPEC O86:H34 and EHEC O157:H7). By using PCR primers designed on the basis of the intimin-encoding eae gene sequences of serotype O127:H6, O114:H2, and O86:H34 EPEC and serotype O157:H7 EHEC, we could distinguish between different eae gene derivatives. Accordingly, the different intimin types were designated alpha, beta, delta, and gamma, respectively.
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Affiliation(s)
- J Adu-Bobie
- Department of Biochemistry, Imperial College of Science, Technology and Medicine, London, United Kingdom
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