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O’Malley MR, Kpenu E, Peck SC, Anderson JC. Plant-exuded chemical signals induce surface attachment of the bacterial pathogen Pseudomonas syringae. PeerJ 2023; 11:e14862. [PMID: 37009160 PMCID: PMC10062345 DOI: 10.7717/peerj.14862] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 01/17/2023] [Indexed: 03/29/2023] Open
Abstract
Many plant pathogenic bacteria suppress host defenses by secreting small molecule toxins or immune-suppressing proteins into host cells, processes that likely require close physical contact between pathogen and host. Yet, in most cases, little is known about whether phytopathogenic bacteria physically attach to host surfaces during infection. Here we report that Pseudomonas syringae pv. tomato strain DC3000, a Gram-negative bacterial pathogen of tomato and Arabidopsis, attaches to polystyrene and glass surfaces in response to chemical signals exuded from Arabidopsis seedlings and tomato leaves. We characterized the molecular nature of these attachment-inducing signals and discovered that multiple hydrophilic metabolites found in plant exudates, including citric acid, glutamic acid, and aspartic acid, are potent inducers of surface attachment. These same compounds were previously identified as inducers of P. syringae genes encoding a type III secretion system (T3SS), indicating that both attachment and T3SS deployment are induced by the same plant signals. To test if surface attachment and T3SS are regulated by the same signaling pathways, we assessed the attachment phenotypes of several previously characterized DC3000 mutants, and found that the T3SS master regulator HrpL was partially required for maximal levels of surface attachment, whereas the response regulator GacA, a negative regulator of T3SS, negatively regulated DC3000 surface attachment. Together, our data indicate that T3SS deployment and surface attachment by P. syringae may be co-regulated by the same host signals during infection, possibly to ensure close contact necessary to facilitate delivery of T3SS effectors into host cells.
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Affiliation(s)
- Megan R. O’Malley
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, United States of America
| | - Eyram Kpenu
- Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, Missouri, United States of America
- Interdisciplinary Plant Group, University of Missouri, Columbia, Missouri, United States of America
| | - Scott C. Peck
- Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, Missouri, United States of America
- Interdisciplinary Plant Group, University of Missouri, Columbia, Missouri, United States of America
- Department of Biochemistry, University of Missouri, Columbia, Missouri, United States of America
| | - Jeffrey C. Anderson
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, United States of America
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2
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Genetic and Antimicrobial Resistance Profiles of Mammary Pathogenic E. coli (MPEC) Isolates from Bovine Clinical Mastitis. Pathogens 2022; 11:pathogens11121435. [PMID: 36558768 PMCID: PMC9781227 DOI: 10.3390/pathogens11121435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 11/24/2022] [Accepted: 11/25/2022] [Indexed: 12/02/2022] Open
Abstract
Mammary pathogenic E. coli (MPEC) is one of the main pathogens of environmental origin responsible for causing clinical mastitis worldwide. Even though E. coli are strongly associated with transient or persistent mastitis and the economic impacts of this disease, the virulence factors involved in the pathogenesis of MPEC remain unknown. Our aim was to characterize 110 MPEC isolates obtained from the milk of cows with clinical mastitis, regarding the virulence factor-encoding genes present, adherence patterns on HeLa cells, and antimicrobial resistance profile. The MPEC isolates were classified mainly in phylogroups A (50.9%) and B1 (38.2%). None of the isolates harbored genes used for diarrheagenic E. coli classification, but 26 (23.6%) and 4 (3.6%) isolates produced the aggregative or diffuse adherence pattern, respectively. Among the 22 genes investigated, encoding virulence factors associated with extraintestinal pathogenic E. coli pathogenesis, fimH (93.6%) was the most frequent, followed by traT (77.3%) and ompT (68.2%). Pulsed-field gel electrophoresis analysis revealed six pulse-types with isolates obtained over time, thus indicating persistent intramammary infections. The genes encoding beta-lactamases detected were as follows: blaTEM (35/31.8%); blaCTX-M-2/blaCTX-M-8 (2/1.8%); blaCTX-M-15 and blaCMY-2 (1/0.9%); five isolates were classified as extended spectrum beta-lactamase (ESBL) producers. As far as we know, papA, shf, ireA, sat and blaCTX-M-8 were detected for the first time in MPEC. In summary, the genetic profile of the MPEC studied was highly heterogeneous, making it impossible to establish a common genetic profile useful for molecular MPEC classification. Moreover, the detection of ESBL-producing isolates is a serious public health concern.
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3
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Saldaña-Ahuactzi Z, Soria-Bustos J, Martínez-Santos VI, Yañez-Santos JA, Martínez-Laguna Y, Cedillo-Ramirez ML, Puente JL, Girón JA. The Fis Nucleoid Protein Negatively Regulates the Phase Variation fimS Switch of the Type 1 Pilus Operon in Enteropathogenic Escherichia coli. Front Microbiol 2022; 13:882563. [PMID: 35572706 PMCID: PMC9096935 DOI: 10.3389/fmicb.2022.882563] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 03/23/2022] [Indexed: 01/02/2023] Open
Abstract
In Escherichia coli the expression of type 1 pili (T1P) is determined by the site-specific inversion of the fimS ON–OFF switch located immediately upstream of major fimbrial subunit gene fimA. Here we investigated the role of virulence (Ler, GrlR, and GrlA) and global regulators (H-NS, IHF, and Fis) in the regulation of the fimS switch in the human enteropathogenic E. coli (EPEC) O127:H6 strain E2348/69. This strain does not produce detectable T1P and PCR analysis of the fimS switch confirmed that it is locked in the OFF orientation. Among the regulator mutants analyzed, only the ∆fis mutant produced significantly high levels of T1P on its surface and yielded high titers of agglutination of guinea pig erythrocytes. Expression analysis of the fimA, fimB, and fimE promoters using lacZ transcriptional fusions indicated that only PfimA activity is enhanced in the absence of Fis. Collectively, these data demonstrate that Fis is a negative regulator of T1P expression in EPEC and suggest that it is required for the FimE-dependent inversion of the fimS switch from the ON-to-OFF direction. It is possible that a similar mechanism of T1P regulation exists in other intestinal and extra-intestinal pathogenic classes of E. coli.
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Affiliation(s)
- Zeus Saldaña-Ahuactzi
- Paul G. Allen School for Global Health, College of Veterinary Medicine, Washington State University, Pullman, WA, United States
| | - Jorge Soria-Bustos
- Instituto de Ciencias de la Salud, Universidad Autónoma del Estado de Hidalgo, Pachuca, Mexico
| | | | - Jorge A Yañez-Santos
- Facultad de Estomatología, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico
| | - Ygnacio Martínez-Laguna
- Centro de Investigaciones en Ciencias Microbiológicas, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico
| | | | - José L Puente
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Jorge A Girón
- Centro de Detección Biomolecular, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico
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4
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Muchaamba F, Barmettler K, Treier A, Houf K, Stephan R. Microbiology and Epidemiology of Escherichia albertii—An Emerging Elusive Foodborne Pathogen. Microorganisms 2022; 10:microorganisms10050875. [PMID: 35630320 PMCID: PMC9145129 DOI: 10.3390/microorganisms10050875] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 04/19/2022] [Accepted: 04/19/2022] [Indexed: 02/03/2023] Open
Abstract
Escherichia albertii, a close relative of E. coli, is an emerging zoonotic foodborne pathogen associated with watery diarrhea mainly in children and immunocompromised individuals. E. albertii was initially classified as eae-positive Hafnia alvei, however, as more genetic and biochemical information became available it was reassigned to its current novel taxonomy. Its infections are common under conditions of poor hygiene with confirmed transmission via contaminated water and food, mainly poultry-based products. This pathogen has been isolated from various domestic and wild animals, with most isolates being derived from birds, implying that birds among other wild animals might act as its reservoir. Due to the absence of standardized isolation and identification protocols, E. albertii can be misidentified as other Enterobacteriaceae. Exploiting phenotypes such as its inability to ferment rhamnose and xylose and PCR assays targeting E. albertii-specific genes such as the cytolethal distending toxin and the DNA-binding transcriptional activator of cysteine biosynthesis encoding genes can be used to accurately identify this pathogen. Several gaps exist in our knowledge of E. albertii and need to be bridged. A deeper understanding of E. albertii epidemiology and physiology is required to allow the development of effective measures to control its transmission and infections. Overall, current data suggest that E. albertii might play a more significant role in global infectious diarrhea cases than previously assumed and is often overlooked or misidentified. Therefore, simple, and efficient diagnostic tools that cover E. albertii biodiversity are required for effective isolation and identification of this elusive agent of diarrhea.
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Affiliation(s)
- Francis Muchaamba
- Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, 8057 Zurich, Switzerland; (K.B.); (A.T.); (R.S.)
- Correspondence:
| | - Karen Barmettler
- Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, 8057 Zurich, Switzerland; (K.B.); (A.T.); (R.S.)
| | - Andrea Treier
- Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, 8057 Zurich, Switzerland; (K.B.); (A.T.); (R.S.)
| | - Kurt Houf
- Department of Veterinary and Biosciences, Faculty of Veterinary Medicine, Ghent University, 9820 Merelbeke, Belgium;
| | - Roger Stephan
- Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, 8057 Zurich, Switzerland; (K.B.); (A.T.); (R.S.)
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5
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Romão FT, Martins FH, Hernandes RT, Ooka T, Santos FF, Yamamoto D, Bonfim-Melo A, Jones N, Hayashi T, Elias WP, Sperandio V, Gomes TAT. Genomic Properties and Temporal Analysis of the Interaction of an Invasive Escherichia albertii With Epithelial Cells. Front Cell Infect Microbiol 2020; 10:571088. [PMID: 33392102 PMCID: PMC7772469 DOI: 10.3389/fcimb.2020.571088] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 11/03/2020] [Indexed: 12/17/2022] Open
Abstract
Diarrhea is one of the main causes of infant mortality worldwide, mainly in the developing world. Among the various etiologic agents, Escherichia albertii is emerging as an important human enteropathogen. E. albertii promote attaching and effacing (AE) lesions due to the presence of the locus of enterocyte effacement (LEE) that encodes a type three secretion system (T3SS), the afimbrial adhesin intimin and its translocated receptor, Tir, and several effector proteins. We previously showed that E. albertii strain 1551-2 invades several epithelial cell lineages by a process that is dependent on the intimin-Tir interaction. To understand the contribution of T3SS-dependent effectors present in E. albertii 1551-2 during the invasion process, we performed a genetic analysis of the LEE and non-LEE genes and evaluated the expression of the LEE operons in various stages of bacterial interaction with differentiated intestinal Caco-2 cells. The kinetics of the ability of the 1551-2 strain to colonize and form AE lesions was also investigated in epithelial HeLa cells. We showed that the LEE expression was constant during the early stages of infection but increased at least 4-fold during bacterial persistence in the intracellular compartment. An in silico analysis indicated the presence of a new tccP/espFU subtype, named tccP3. We found that the encoded protein colocalizes with Tir and polymerized F-actin during the infection process in vitro. Moreover, assays performed with Nck null cells demonstrated that the 1551-2 strain can trigger F-actin polymerization in an Nck-independent pathway, despite the fact that TccP3 is not required for this phenotype. Our study highlights the importance of the T3SS during the invasion process and for the maintenance of E. albertii 1551-2 inside the cells. In addition, this work may help to elucidate the versatility of the T3SS for AE pathogens, which are usually considered extracellular and rarely reach the intracellular environment.
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Affiliation(s)
- Fabiano T Romão
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo (EPM-UNIFESP), São Paulo, Brazil.,Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX, United States.,Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Fernando H Martins
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX, United States.,Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, United States.,Laboratório de Bacteriologia, Instituto Butantan, São Paulo, Brazil
| | - Rodrigo T Hernandes
- Instituto de Biociências, Universidade Estadual Paulista (UNESP), Botucatu, Brazil
| | - Tadasuke Ooka
- Department of Microbiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Fernanda F Santos
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo (EPM-UNIFESP), São Paulo, Brazil
| | - Denise Yamamoto
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo (EPM-UNIFESP), São Paulo, Brazil.,Universidade Santo Amaro, São Paulo, Brazil
| | - Alexis Bonfim-Melo
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo (EPM-UNIFESP), São Paulo, Brazil
| | - Nina Jones
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, Canada
| | - Tetsuya Hayashi
- Department of Bacteriology, Faculty of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Waldir P Elias
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, Brazil
| | - Vanessa Sperandio
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX, United States.,Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Tânia A T Gomes
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo (EPM-UNIFESP), São Paulo, Brazil
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6
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Valiatti TB, Santos FF, Santos ACM, Nascimento JAS, Silva RM, Carvalho E, Sinigaglia R, Gomes TAT. Genetic and Virulence Characteristics of a Hybrid Atypical Enteropathogenic and Uropathogenic Escherichia coli (aEPEC/UPEC) Strain. Front Cell Infect Microbiol 2020; 10:492. [PMID: 33134184 PMCID: PMC7550682 DOI: 10.3389/fcimb.2020.00492] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 08/08/2020] [Indexed: 12/23/2022] Open
Abstract
Hybrid strains of Escherichia coli combine virulence traits of diarrheagenic (DEC) and extraintestinal pathogenic E. coli (ExPEC), but it is poorly understood whether these combined features improve the virulence potential of such strains. We have previously identified a uropathogenic E. coli (UPEC) strain (UPEC 252) harboring the eae gene that encodes the adhesin intimin and is located in the locus of enterocyte effacement (LEE) pathogenicity island. The LEE-encoded proteins allow enteropathogenic E. coli (EPEC) and enterohemorrhagic E. coli (EHEC) to form attaching and effacing (A/E) lesions in enterocytes. We sought to characterize UPEC 252 through whole-genome sequencing and phenotypic virulence assays. Genome analysis unveiled that this strain harbors a complete LEE region, with more than 97% of identity comparing to E2348/69 (EPEC) and O157:H7 Sakai (EHEC) prototype strains, which was functional, since UPEC 252 expressed the LEE-encoded proteins EspB and intimin and induced actin accumulation foci in HeLa cells. Phylogenetic analysis performed comparing 1,000 single-copy shared genes clustered UPEC 252 with atypical EPEC strains that belong to the sequence type 10, phylogroup A. Additionally, UPEC 252 was resistant to the bactericidal power of human serum and colonized cells of the urinary (T24 and HEK293-T) and intestinal (Caco-2 and LS174T) tracts. Our findings suggest that UPEC 252 is an atypical EPEC strain that emerges as a hybrid strain (aEPEC/UPEC), which could colonize new niches and potentially cause intestinal and extraintestinal infections.
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Affiliation(s)
- Tiago B Valiatti
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Fernanda F Santos
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Ana C M Santos
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Júllia A S Nascimento
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Rosa M Silva
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Eneas Carvalho
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, Brazil
| | - Rita Sinigaglia
- Centro de Microscopia Eletrônica, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Tânia A T Gomes
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
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7
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Gomes TAT, Ooka T, Hernandes RT, Yamamoto D, Hayashi T. Escherichia albertii Pathogenesis. EcoSal Plus 2020; 9:10.1128/ecosalplus.ESP-0015-2019. [PMID: 32588811 PMCID: PMC11168576 DOI: 10.1128/ecosalplus.esp-0015-2019] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Indexed: 12/17/2022]
Abstract
Escherichia albertii is an emerging enteropathogen of humans and many avian species. This bacterium is a close relative of Escherichia coli and has been frequently misidentified as enteropathogenic or enterohemorrhagic E. coli due to their similarity in phenotypic and genetic features, such as various biochemical properties and the possession of a type III secretion system encoded by the locus of enterocyte effacement. This pathogen causes outbreaks of gastroenteritis, and some strains produce Shiga toxin. Although many genetic and phenotypic studies have been published and the genome sequences of more than 200 E. albertii strains are now available, the clinical significance of this species is not yet fully understood. The apparent zoonotic nature of the disease requires a deeper understanding of the transmission routes and mechanisms of E. albertii to develop effective measures to control its transmission and infection. Here, we review the current knowledge of the phylogenic relationship of E. albertii with other Escherichia species and the biochemical and genetic properties of E. albertii, with particular emphasis on the repertoire of virulence factors and the mechanisms of pathogenicity, and we hope this provides a basis for future studies of this important emerging enteropathogen.
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Affiliation(s)
- Tânia A T Gomes
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Tadasuke Ooka
- Department of Microbiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Rodrigo T Hernandes
- Universidade Estadual Paulista (UNESP), Instituto de Biociências, Campus de Botucatu, São Paulo, Brazil
| | - Denise Yamamoto
- Universidade Santo Amaro, São Paulo, Brazil
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Tetsuya Hayashi
- Department of Bacteriology, Faculty of Medical Sciences, Kyushu University, Fukuoka, Japan
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8
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Dharamshi JE, Tamarit D, Eme L, Stairs CW, Martijn J, Homa F, Jørgensen SL, Spang A, Ettema TJG. Marine Sediments Illuminate Chlamydiae Diversity and Evolution. Curr Biol 2020; 30:1032-1048.e7. [PMID: 32142706 DOI: 10.1016/j.cub.2020.02.016] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 12/22/2019] [Accepted: 02/06/2020] [Indexed: 12/20/2022]
Abstract
The bacterial phylum Chlamydiae is so far composed of obligate symbionts of eukaryotic hosts. Well known for Chlamydiaceae, pathogens of humans and other animals, Chlamydiae also include so-called environmental lineages that primarily infect microbial eukaryotes. Environmental surveys indicate that Chlamydiae are found in a wider range of environments than anticipated previously. However, the vast majority of this chlamydial diversity has been underexplored, biasing our current understanding of their biology, ecological importance, and evolution. Here, we report that previously undetected and active chlamydial lineages dominate microbial communities in deep anoxic marine sediments taken from the Arctic Mid-Ocean Ridge. Reaching relative abundances of up to 43% of the bacterial community, and a maximum diversity of 163 different species-level taxonomic units, these Chlamydiae represent important community members. Using genome-resolved metagenomics, we reconstructed 24 draft chlamydial genomes, expanding by over a third the known genomic diversity in this phylum. Phylogenomic analyses revealed several novel clades across the phylum, including a previously unknown sister lineage of the Chlamydiaceae, providing new insights into the origin of pathogenicity in this family. We were unable to identify putative eukaryotic hosts for these marine sediment chlamydiae, despite identifying genomic features that may be indicative of host-association. The high abundance and genomic diversity of Chlamydiae in these anoxic marine sediments indicate that some members could play an important, and thus far overlooked, ecological role in such environments and may indicate alternate lifestyle strategies.
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Affiliation(s)
- Jennah E Dharamshi
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, Uppsala 75123, Sweden
| | - Daniel Tamarit
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, Uppsala 75123, Sweden; Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, Wageningen 6708 WE, the Netherlands
| | - Laura Eme
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, Uppsala 75123, Sweden; Unité d'Ecologie, Systématique et Evolution, CNRS, Université Paris-Sud, Orsay 91400, France
| | - Courtney W Stairs
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, Uppsala 75123, Sweden
| | - Joran Martijn
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, Uppsala 75123, Sweden; Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Felix Homa
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, Uppsala 75123, Sweden; Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, Wageningen 6708 WE, the Netherlands
| | - Steffen L Jørgensen
- Department of Earth Science, Centre for Deep Sea Research, University of Bergen, Bergen 5020, Norway
| | - Anja Spang
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, Uppsala 75123, Sweden; Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, and Utrecht University, Den Burg 1790 AB, the Netherlands
| | - Thijs J G Ettema
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, Uppsala 75123, Sweden; Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, Wageningen 6708 WE, the Netherlands.
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9
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Lima MP, Yamamoto D, Santos ACDM, Ooka T, Hernandes RT, Vieira MAM, Santos FF, Silva RM, Hayashi T, Gomes TAT. Phenotypic characterization and virulence-related properties of Escherichia albertii strains isolated from children with diarrhea in Brazil. Pathog Dis 2020; 77:5379300. [PMID: 30865776 DOI: 10.1093/femspd/ftz014] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 03/12/2019] [Indexed: 11/14/2022] Open
Abstract
Escherichia albertii are emerging enteropathogens, whose identification is difficult, as they share biochemical characteristics and some virulence-related genes with diarrheagenic Escherichia coli (DEC). Studies on phylogeny, phenotypic characteristics and potential virulence factors of human E. albertii strains are scarce. In this study, we identified by multiplex PCR five E. albertii among 106 strains isolated from diarrheic children in São Paulo, Brazil, which were previously classified as atypical enteropathogenic E. coli. All strains were investigated regarding their phylogeny, biochemical properties, virulence-related properties, antimicrobial resistance and presence of putative virulence-related genes. All strains belonged to different E. albertii lineages and adhered to and produced attaching and effacing lesions on HeLa cells. Three strains invaded Caco-2 cells, but did not persist intracellularly, and three formed biofilms on polystyrene surfaces. All strains were resistant to few antibiotics and only one carried a self-transmissible resistance plasmid. Finally, among 38 DEC and 18 extraintestinal pathogenic E. coli (ExPEC) virulence-related genes searched, six and three were detected, respectively, with paa and cdtB being found in all strains. Despite the limited number of strains, this study provided additional knowledge on human E. albertii virulence potential, showing that they share important virulence factors with DEC and ExPEC.
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Affiliation(s)
- Mauricio P Lima
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina (UNIFESP-EPM), Universidade Federal de São Paulo, Rua Botucatu, 862, 3° andar, CEP 04023-062, São Paulo, SP, Brazil
| | - Denise Yamamoto
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina (UNIFESP-EPM), Universidade Federal de São Paulo, Rua Botucatu, 862, 3° andar, CEP 04023-062, São Paulo, SP, Brazil.,Rua Prof. Enéas de Siqueira Neto, Universidade Santo Amaro (UNISA), 340 CEP 04829-300-São Paulo, SP, Brazil
| | - Ana Carolina de Mello Santos
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina (UNIFESP-EPM), Universidade Federal de São Paulo, Rua Botucatu, 862, 3° andar, CEP 04023-062, São Paulo, SP, Brazil
| | - Tadasuke Ooka
- Department of Microbiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Rodrigo T Hernandes
- Departamento de Microbiologia e Imunologia, Instituto de Biociências, Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Distrito de Rubião Jr. CEP 18618-691, Botucatu, SP, Brazil
| | - Mônica A M Vieira
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina (UNIFESP-EPM), Universidade Federal de São Paulo, Rua Botucatu, 862, 3° andar, CEP 04023-062, São Paulo, SP, Brazil
| | - Fernanda Fernandes Santos
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina (UNIFESP-EPM), Universidade Federal de São Paulo, Rua Botucatu, 862, 3° andar, CEP 04023-062, São Paulo, SP, Brazil
| | - Rosa Maria Silva
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina (UNIFESP-EPM), Universidade Federal de São Paulo, Rua Botucatu, 862, 3° andar, CEP 04023-062, São Paulo, SP, Brazil
| | - Tetsuya Hayashi
- Department of Bacteriology, Faculty of Medical Sciences, Kyushu University, 3-1-1 Maedashi, Higashi-ku, Fukuoka City, Fukuoka Prefecture 812-8582, Japan
| | - Tânia A T Gomes
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina (UNIFESP-EPM), Universidade Federal de São Paulo, Rua Botucatu, 862, 3° andar, CEP 04023-062, São Paulo, SP, Brazil
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Dias RCB, Vieira MA, Moro AC, Ribolli DFM, Monteiro ACM, Camargo CH, Tiba-Casas MR, Soares FB, Dos Santos LF, Montelli AC, da Cunha MDLRDS, Barretti P, Hernandes RT. Characterization of Escherichia coli obtained from patients undergoing peritoneal dialysis and diagnosed with peritonitis in a Brazilian centre. J Med Microbiol 2019; 68:1330-1340. [PMID: 31347999 DOI: 10.1099/jmm.0.001043] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Purpose. This study aimed to characterize 27 Escherichia coli isolates obtained from peritoneal dialysis (PD)-related peritonitis that occurred at the University Hospital of Botucatu Medical School, Brazil, between 1997 and 2015.Methodology. These isolates were characterized regarding the occurrence of 22 virulence factor-encoding genes, antimicrobial resistance and biofilm production. We then evaluated whether these factors influenced the clinical outcome.Results. Over an 18-year period, 726 episodes of PD-related peritonitis were diagnosed, with 27 of them (3.7 %) being due to E. coli. The majority of the isolates were classified in phylogroups B1 (33.3 %), B2 (30.0 %) or F (18.0 %). fimH (100.0 %), ompT (66.7 %) and irp2 (51.9 %) were the most prevalent genes, while papA, papC, iha, sat, irp2, iucD, ireA, ibe10, ompT and kpsMTII were significantly more prevalent among isolates belonging to phylogroups B2 and F (P<0.05). Non-susceptibility to quinolones was detected in six isolates, which harboured chromosomal and/or plasmid-mediated quinolone resistance determinants, while two CTX-M extended-spectrum β-lactamase-producing E. coli were identified. Virulence factor-encoding genes (alone or in combination) and antimicrobial resistance were not associated with non-resolution outcomes. However, there was a trend for the ability to produce biofilm to be associated with treatment failure, although this association was not statistically significant.Conclusion. The E. coli isolates were heterogeneous in terms of the features investigated, and were susceptible to most of the antimicrobial drugs tested, despite the unsuccessful treatment observed in more than 50.0 % of the patients. Studies including more cases could help to clarify if biofilm production can influence the outcome in patients with PD-related peritonitis.
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Affiliation(s)
- Regiane C B Dias
- Departamento de Microbiologia e Imunologia, Instituto de Biociências, Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Botucatu, SP, Brazil
| | - Melissa A Vieira
- Departamento de Microbiologia e Imunologia, Instituto de Biociências, Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Botucatu, SP, Brazil
| | - Ana C Moro
- Departamento de Microbiologia e Imunologia, Instituto de Biociências, Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Botucatu, SP, Brazil
| | - Danilo F M Ribolli
- Departamento de Microbiologia e Imunologia, Instituto de Biociências, Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Botucatu, SP, Brazil
| | - Aydir C M Monteiro
- Departamento de Microbiologia e Imunologia, Instituto de Biociências, Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Botucatu, SP, Brazil
| | - Carlos H Camargo
- Centro de Bacteriologia, Instituto Adolfo Lutz, São Paulo, SP, Brazil
| | | | - Flávia B Soares
- Centro de Bacteriologia, Instituto Adolfo Lutz, São Paulo, SP, Brazil
| | - Luis F Dos Santos
- Centro de Bacteriologia, Instituto Adolfo Lutz, São Paulo, SP, Brazil
| | - Augusto C Montelli
- Departamento de Clínica Médica, Faculdade de Medicina, Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Botucatu, SP, Brazil.,Departamento de Microbiologia e Imunologia, Instituto de Biociências, Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Botucatu, SP, Brazil
| | - Maria de Lourdes R de S da Cunha
- Departamento de Microbiologia e Imunologia, Instituto de Biociências, Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Botucatu, SP, Brazil
| | - Pasqual Barretti
- Departamento de Clínica Médica, Faculdade de Medicina, Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Botucatu, SP, Brazil
| | - Rodrigo T Hernandes
- Departamento de Microbiologia e Imunologia, Instituto de Biociências, Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Botucatu, SP, Brazil
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Santos FF, Yamamoto D, Abe CM, Bryant JA, Hernandes RT, Kitamura FC, Castro FS, Valiatti TB, Piazza RMF, Elias WP, Henderson IR, Gomes TAT. The Type III Secretion System (T3SS)-Translocon of Atypical Enteropathogenic Escherichia coli (aEPEC) Can Mediate Adherence. Front Microbiol 2019; 10:1527. [PMID: 31338081 PMCID: PMC6629874 DOI: 10.3389/fmicb.2019.01527] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 06/18/2019] [Indexed: 12/18/2022] Open
Abstract
The intimin protein is the major adhesin involved in the intimate adherence of atypical enteropathogenic Escherichia coli (aEPEC) strains to epithelial cells, but little is known about the structures involved in their early colonization process. A previous study demonstrated that the type III secretion system (T3SS) plays an additional role in the adherence of an Escherichia albertii strain. Therefore, we assumed that the T3SS could be related to the adherence efficiency of aEPEC during the first stages of contact with epithelial cells. To test this hypothesis, we examined the adherence of seven aEPEC strains and their eae (intimin) isogenic mutants in the standard HeLa adherence assay and observed that all wild-type strains were adherent while five isogenic eae mutants were not. The two eae mutant strains that remained adherent were then used to generate the eae/escN double mutants (encoding intimin and the T3SS ATPase, respectively) and after the adherence assay, we observed that one strain lost its adherence capacity. This suggested a role for the T3SS in the initial adherence steps of this strain. In addition, we demonstrated that this strain expressed the T3SS at significantly higher levels when compared to the other wild-type strains and that it produced longer translocon-filaments. Our findings reveal that the T3SS-translocon can play an additional role as an adhesin at the beginning of the colonization process of aEPEC.
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Affiliation(s)
- Fernanda F Santos
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Denise Yamamoto
- 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
| | - Jack A Bryant
- Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Rodrigo T Hernandes
- Departamento de Microbiologia e Imunologia, Instituto de Biociências, Universidade Estadual Paulista, Botucatu, Brazil
| | - Felipe C Kitamura
- Departamento de Diagnóstico por Imagem, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Felipe S Castro
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Tiago B Valiatti
- 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
| | - Ian R Henderson
- Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Tânia A T Gomes
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
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First Microbiological and Molecular Identification of Rhodococcus equi in Feces of Nondiarrheic Cats. BIOMED RESEARCH INTERNATIONAL 2019; 2019:4278598. [PMID: 31380423 PMCID: PMC6652081 DOI: 10.1155/2019/4278598] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 06/16/2019] [Indexed: 12/28/2022]
Abstract
Rhodococcus equi is responsible for infections in multiple-host animals. In humans, the prevalence of rhodococcus has increased worldwide and represents an emergent risk. R. equi is a soil-borne opportunistic bacterium isolated from feces of a wide variety of domestic species, except cats; thus, there is no known potential risk of its transmission from humans. Here, the mono- and cooccurrence of Rhodococcus equi and other bacteria and selected virulence markers were investigated in feces of nondiarrheic cats from urban (n=100) and rural (n=100) areas. Seven (7/200=3.5%) R. equi isolates were recovered in ceftazidime, novobiocin, and cycloheximide (CAZ-NB) selective media, exclusively of cats from three distinct farms (p=0.01), and these cats had a history of contact with horses and their environment (p=0.0002). None of the R. equi isolates harbored hosted-adapted plasmid types associated with virulence (pVAPA, pVAPB, and pVAPN). One hundred seventy-five E. coli isolates were identified, and 23 atypical enteropathogenic E. coli (aEPEC), 1 STEC (Shiga-toxin producing E. coli), and 1 EAEC (enteroaggregative E. coli) were detected. Eighty-six C. perfringens type A isolates were identified, and beta-2 and enterotoxin were detected in 21 and 1 isolates, respectively. Five C. difficile isolates were identified, one of which was toxigenic and ribotype 106. The main cooccurring isolates in cats from urban areas were E. coli and C. perfringens A (26/100=26%), E. coli and C. perfringens type A cpb2+ (8/100=8%), and aEPEC (eae+/escN+) and C. perfringens type A (5/100=5%). In cats from farms, the main cooccurring isolates were E. coli and C. perfringens type A (21/100=21%), E. coli and C. perfringens type A cpb2+ 8/100=8%), and E. coli and R. equi (4/100=4%). We identified, for the first time, R. equi in nondiarrheic cats, a finding that represents a public health issue because rhodococcus has been reported in both immunosuppressed and immunocompetent humans, particularly people living with HIV/AIDS.
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Zuo J, Tu C, Wang Y, Qi K, Hu J, Wang Z, Mi R, Yan huang, Chen Z, Han X. The role of the wzy gene in lipopolysaccharide biosynthesis and pathogenesis of avian pathogenic Escherichia coli. Microb Pathog 2019; 127:296-303. [DOI: 10.1016/j.micpath.2018.12.021] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 12/11/2018] [Accepted: 12/11/2018] [Indexed: 01/08/2023]
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14
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Culler HF, Couto SCF, Higa JS, Ruiz RM, Yang MJ, Bueris V, Franzolin MR, Sircili MP. Role of SdiA on Biofilm Formation by Atypical Enteropathogenic Escherichia coli. Genes (Basel) 2018; 9:genes9050253. [PMID: 29762495 PMCID: PMC5977193 DOI: 10.3390/genes9050253] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 02/19/2018] [Accepted: 02/21/2018] [Indexed: 01/11/2023] Open
Abstract
Atypical enteropathogenic Escherichia coli are capable to form biofilm on biotic and abiotic surfaces, regardless of the adherence pattern displayed. Several E. coli mechanisms are regulated by Quorum sensing (QS), including virulence factors and biofilm formation. Quorum sensing is a signaling system that confers bacteria with the ability to respond to chemical molecules known as autoinducers. Suppressor of division inhibitor (SdiA) is a QS receptor present in atypical enteropathogenic E.coli (aEPEC) that detects acyl homoserine lactone (AHL) type autoinducers. However, these bacteria do not encode an AHL synthase, but they are capable of sensing AHL molecules produced by other species, establishing an inter-species bacterial communication. In this study, we performed experiments to evaluate pellicle, ring-like structure and biofilm formation on wild type, sdiA mutants and complemented strains. We also evaluated the transcription of genes involved in different stages of biofilm formation, such as bcsA, csgA, csgD, fliC and fimA. The sdiA mutants were capable of forming thicker biofilm structures and showed increased motility when compared to wild type and complemented strains. Moreover, they also showed denser pellicles and ring-like structures. Quantitative real-time PCR (qRT-PCR) analysis demonstrated increased csgA, csgD and fliC transcription on mutant strains. Biofilm formation, as well as csgD, csgA and fimA transcription decreased on wild type strains by the addition of AHL. These results indicate that SdiA participates on the regulation of these phenotypes in aEPEC and that AHL addition enhances the repressor effect of this receptor on the transcription of biofilm and motility related genes.
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Affiliation(s)
- Hebert F Culler
- Laboratory of Genetics, Butantan Institute, São Paulo 05503-900, Brazil.
| | - Samuel C F Couto
- Laboratory of Genetics, Butantan Institute, São Paulo 05503-900, Brazil.
| | - Juliana S Higa
- Laboratory of Genetics, Butantan Institute, São Paulo 05503-900, Brazil.
| | - Renato M Ruiz
- Laboratory of Genetics, Butantan Institute, São Paulo 05503-900, Brazil.
| | - Min J Yang
- Laboratory of Genetics, Butantan Institute, São Paulo 05503-900, Brazil.
| | - Vanessa Bueris
- Laboratory of Genetics, Butantan Institute, São Paulo 05503-900, Brazil.
| | - Marcia R Franzolin
- Laboratory of Bacteriology, Butantan Institute, São Paulo 05503-900, Brazil.
| | - Marcelo P Sircili
- Laboratory of Genetics, Butantan Institute, São Paulo 05503-900, Brazil.
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Abstract
Escherichia coli has a complex and versatile nature and continuously evolves from non-virulent isolates to highly pathogenic strains causing severe diseases and outbreaks. Broadly protective vaccines against pathogenic E. coli are not available and the rising in both, multi-drug resistant and hypervirulent isolates, raise concern for healthcare and require continuous efforts in epidemiologic surveillance and disease monitoring. The evolving knowledge on E. coli pathogenesis mechanisms and on the mediated immune response following infection or vaccination, together with advances in the "omics" technologies, is opening new perspectives toward the design and development of effective and innovative E. coli vaccines.
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16
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Abstract
Type II secretion (T2S) is one means by which Gram-negative pathogens secrete proteins into the extracellular milieu and/or host organisms. Based upon recent genome sequencing, it is clear that T2S is largely restricted to the Proteobacteria, occurring in many, but not all, genera in the Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, and Deltaproteobacteria classes. Prominent human and/or animal pathogens that express a T2S system(s) include Acinetobacter baumannii, Burkholderia pseudomallei, Chlamydia trachomatis, Escherichia coli, Klebsiella pneumoniae, Legionella pneumophila, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Vibrio cholerae, and Yersinia enterocolitica T2S-expressing plant pathogens include Dickeya dadantii, Erwinia amylovora, Pectobacterium carotovorum, Ralstonia solanacearum, Xanthomonas campestris, Xanthomonas oryzae, and Xylella fastidiosa T2S also occurs in nonpathogenic bacteria, facilitating symbioses, among other things. The output of a T2S system can range from only one to dozens of secreted proteins, encompassing a diverse array of toxins, degradative enzymes, and other effectors, including novel proteins. Pathogenic processes mediated by T2S include the death of host cells, degradation of tissue, suppression of innate immunity, adherence to host surfaces, biofilm formation, invasion into and growth within host cells, nutrient assimilation, and alterations in host ion flux. The reach of T2S is perhaps best illustrated by those bacteria that clearly use it for both environmental survival and virulence; e.g., L. pneumophila employs T2S for infection of amoebae, growth within lung cells, dampening of cytokines, and tissue destruction. This minireview provides an update on the types of bacteria that have T2S, the kinds of proteins that are secreted via T2S, and how T2S substrates promote infection.
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Escherichia albertii, a novel human enteropathogen, colonizes rat enterocytes and translocates to extra-intestinal sites. PLoS One 2017; 12:e0171385. [PMID: 28178312 PMCID: PMC5298312 DOI: 10.1371/journal.pone.0171385] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 01/18/2017] [Indexed: 01/01/2023] Open
Abstract
Diarrhea is the second leading cause of death of children up to five years old in the developing countries. Among the etiological diarrheal agents are atypical enteropathogenic Escherichia coli (aEPEC), one of the diarrheagenic E. coli pathotypes that affects children and adults, even in developed countries. Currently, genotypic and biochemical approaches have helped to demonstrate that some strains classified as aEPEC are actually E. albertii, a recently recognized human enteropathogen. Studies on particular strains are necessary to explore their virulence potential in order to further understand the underlying mechanisms of E. albertii infections. Here we demonstrated for the first time that infection of fragments of rat intestinal mucosa is a useful tool to study the initial steps of E. albertii colonization. We also observed that an E. albertii strain can translocate from the intestinal lumen to Mesenteric Lymph Nodes and liver in a rat model. Based on our finding of bacterial translocation, we investigated how E. albertii might cross the intestinal epithelium by performing infections of M-like cells in vitro to identify the potential in vivo translocation route. Altogether, our approaches allowed us to draft a general E. albertii infection route from the colonization till the bacterial spreading in vivo.
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18
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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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Tan L, Moriel DG, Totsika M, Beatson SA, Schembri MA. Differential Regulation of the Surface-Exposed and Secreted SslE Lipoprotein in Extraintestinal Pathogenic Escherichia coli. PLoS One 2016; 11:e0162391. [PMID: 27598999 PMCID: PMC5012682 DOI: 10.1371/journal.pone.0162391] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Accepted: 08/22/2016] [Indexed: 11/19/2022] Open
Abstract
Extra-intestinal pathogenic Escherichia coli (ExPEC) are responsible for diverse infections including meningitis, sepsis and urinary tract infections. The alarming rise in anti-microbial resistance amongst ExPEC complicates treatment and has highlighted the need for alternative preventive measures. SslE is a lipoprotein secreted by a dedicated type II secretion system in E. coli that was first identified as a potential vaccine candidate using reverse genetics. Although the function and protective efficacy of SslE has been studied, the molecular mechanisms that regulate SslE expression remain to be fully elucidated. Here, we show that while the expression of SslE can be detected in E. coli culture supernatants, different strains express and secrete different amounts of SslE when grown under the same conditions. While the histone-like transcriptional regulator H-NS strongly represses sslE at ambient temperatures, the variation in SslE expression at human physiological temperature suggested a more complex mode of regulation. Using a genetic screen to identify novel regulators of sslE in the high SslE-expressing strain UTI89, we defined a new role for the nucleoid-associated regulator Fis and the ribosome-binding GTPase TypA as positive regulators of sslE transcription. We also showed that Fis-mediated enhancement of sslE transcription is dependent on a putative Fis-binding sequence located upstream of the -35 sequence in the core promoter element, and provide evidence to suggest that Fis may work in complex with H-NS to control SslE expression. Overall, this study has defined a new mechanism for sslE regulation and increases our understanding of this broadly conserved E. coli vaccine antigen.
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Affiliation(s)
- Lendl Tan
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, QLD 4072, Brisbane, Australia
| | - Danilo G. Moriel
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, QLD 4072, Brisbane, Australia
| | - Makrina Totsika
- Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Queensland University of Technology, QLD 4059, Brisbane, Australia
| | - Scott A. Beatson
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, QLD 4072, Brisbane, Australia
| | - Mark A. Schembri
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, QLD 4072, Brisbane, Australia
- * E-mail:
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Michelli E, Millán A, Rodulfo H, Michelli M, Luiggi J, Carreño N, De Donato M. Identification of enteropathogenic Escherichia coli in children with acute diarrheic syndrome from Sucre State, Venezuela. BIOMEDICA : REVISTA DEL INSTITUTO NACIONAL DE SALUD 2016; 36:118-127. [PMID: 27622632 DOI: 10.7705/biomedica.v36i0.2928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 10/11/2015] [Indexed: 06/06/2023]
Abstract
INTRODUCTION Diarrheagenic Escherichia coli is an important causative agent of acute diarrheic syndrome. OBJECTIVE To identify clonal groups of enteropathogenic E. coli (EPEC), in 485 children with acute diarrhea aged 0 to 10 years attending health care centers in Arismendi, Benítez and Sucre municipalities, Sucre state, Venezuela, from March to December, 2011. MATERIALS AND METHODS After obtaining the informed consent, stool samples were collected. Escherichia coli was identified using standard coproculture methods and serology with polyvalent and monovalent antisera. DNA was isolated, and eae (intimin) and bfpA (bundlin) genes were amplified through two multiplex polymerase chain reactions (PCR). RESULTS The presence of bacterial infection was determined in 39.6% of coprocultures. The prevalence of E. coli was 54.7%; 82.9% of these isolates were positive by serology for the evaluated serogroups and serotypes, which were mostly identified in children between 0 and 2 years (37.9%); 48.6% of E. coli strains amplified the eae gene; of these, 58.8% were classified as typical EPEC (eae+ y bfp+). EPEC II was the most common serogroup (38.7%), with predominance of typical EPEC (60%). In positive strains for eae gene, the β intimin allele was the most frequently identified (74.5%). Only four strains with O157:H7 serotype were identified, which showed no PCR amplification of the eae and bfpA genes. CONCLUSION This study showed the importance of molecular tests to identify diarrheagenic E. coli strains causing clinical conditions of varying severity.
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Affiliation(s)
- Elvia Michelli
- Laboratorio de Genética Molecular, Instituto de Investigaciones en Biomedicina y Ciencias Aplicadas "Dra. Susan Tai", Universidad de Oriente, Cumaná, Sucre, Venezuela Laboratorio de Microbiología Clínica, Departamento de Bioanálisis, Universidad de Oriente, Cumaná, Sucre, Venezuela.
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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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Finding Regulators Associated with the Expression of the Long Polar Fimbriae in Enteropathogenic Escherichia coli. J Bacteriol 2015; 197:3658-65. [PMID: 26350135 DOI: 10.1128/jb.00509-15] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 09/02/2015] [Indexed: 01/01/2023] Open
Abstract
UNLABELLED Enteropathogenic Escherichia coli (EPEC) is a human pathogen that requires initial adhesion to the intestine in order to cause disease. Multiple adhesion factors have been identified in E. coli strains, among them the long polar fimbriae (Lpf), a colonization factor associated with intestinal adhesion. The conditions of Lpf expression are well understood in enterohemorrhagic E. coli (EHEC); however, the expression of EPEC lpf has been found to be repressed under any in vitro condition tested. Therefore, we decided to identify those factors silencing expression of EPEC lpf. Because histone-like nucleoid structuring protein (H-NS) is a known repressor of EHEC lpf, we tested it and found that H-NS is a repressor of EPEC lpf. We also found that the adhesion of the EPEC Δhns strain was significantly enhanced compared to the wild-type strain. Because lpf expression was modestly increased in the hns mutant, transposon mutagenesis was performed to find a strain displaying higher lpf expression than EPEC Δhns. One Tn5 insertion was identified within the yhjX gene, and further in vitro characterization revealed increased lpf expression and adhesion to Caco-2 cells compared with EPEC Δhns. However, in a murine model of intestinal infection, the EPEC Δhns and EPEC Δhns Tn5 mutants had only a slight change in colonization pattern compared to the wild-type strain. Our data showed that EPEC Lpf is transcribed, but its role in EPEC intestinal colonization requires further analysis. IMPORTANCE Data are presented demonstrating that the long polar fimbriae (lpf) operon in enteropathogenic E. coli (EPEC) is highly regulated; however, derepression occurs by mutagenizing two proteins associated with its control. The study demonstrates that the EPEC lpf operon can be expressed and, therefore, participates in the EPEC adherence phenotype.
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Giaouris E, Heir E, Desvaux M, Hébraud M, Møretrø T, Langsrud S, Doulgeraki A, Nychas GJ, Kačániová M, Czaczyk K, Ölmez H, Simões M. Intra- and inter-species interactions within biofilms of important foodborne bacterial pathogens. Front Microbiol 2015; 6:841. [PMID: 26347727 PMCID: PMC4542319 DOI: 10.3389/fmicb.2015.00841] [Citation(s) in RCA: 177] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2015] [Accepted: 07/31/2015] [Indexed: 12/15/2022] Open
Abstract
A community-based sessile life style is the normal mode of growth and survival for many bacterial species. Under such conditions, cell-to-cell interactions are inevitable and ultimately lead to the establishment of dense, complex and highly structured biofilm populations encapsulated in a self-produced extracellular matrix and capable of coordinated and collective behavior. Remarkably, in food processing environments, a variety of different bacteria may attach to surfaces, survive, grow, and form biofilms. Salmonella enterica, Listeria monocytogenes, Escherichia coli, and Staphylococcus aureus are important bacterial pathogens commonly implicated in outbreaks of foodborne diseases, while all are known to be able to create biofilms on both abiotic and biotic surfaces. Particularly challenging is the attempt to understand the complexity of inter-bacterial interactions that can be encountered in such unwanted consortia, such as competitive and cooperative ones, together with their impact on the final outcome of these communities (e.g., maturation, physiology, antimicrobial resistance, virulence, dispersal). In this review, up-to-date data on both the intra- and inter-species interactions encountered in biofilms of these pathogens are presented. A better understanding of these interactions, both at molecular and biophysical levels, could lead to novel intervention strategies for controlling pathogenic biofilm formation in food processing environments and thus improve food safety.
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Affiliation(s)
- Efstathios Giaouris
- Department of Food Science and Nutrition, Faculty of the Environment, University of the Aegean, Myrina, Lemnos Island, Greece
| | - Even Heir
- Nofima, Norwegian Institute of Food, Fisheries and Aquaculture Research, Ås, Norway
| | - Mickaël Desvaux
- INRA, UR454 Microbiologie, Centre Auvergne-Rhône-Alpes, Saint-Genès-Champanelle, France
| | - Michel Hébraud
- INRA, UR454 Microbiologie, Centre Auvergne-Rhône-Alpes, Saint-Genès-Champanelle, France
| | - Trond Møretrø
- Nofima, Norwegian Institute of Food, Fisheries and Aquaculture Research, Ås, Norway
| | - Solveig Langsrud
- Nofima, Norwegian Institute of Food, Fisheries and Aquaculture Research, Ås, Norway
| | - Agapi Doulgeraki
- Laboratory of Microbiology and Biotechnology of Foods, Department of Food Science and Human Nutrition, Faculty of Foods, Biotechnology and Development, Agricultural University of Athens, Athens, Greece
| | - George-John Nychas
- Laboratory of Microbiology and Biotechnology of Foods, Department of Food Science and Human Nutrition, Faculty of Foods, Biotechnology and Development, Agricultural University of Athens, Athens, Greece
| | - Miroslava Kačániová
- Department of Microbiology, Faculty of Biotechnology and Food Sciences, Slovak University of Agriculture in Nitra, Nitra, Slovakia
| | - Katarzyna Czaczyk
- Department of Biotechnology and Food Microbiology, Poznan University of Life Sciences, Poznań, Poland
| | - Hülya Ölmez
- TÜBİTAK Marmara Research Center, Food Institute, Gebze, Kocaeli, Turkey
| | - Manuel Simões
- Laboratory for Process Engineering, Environment, Biotechnology and Energy, Department of Chemical Engineering, Faculty of Engineering, University of Porto, Porto, Portugal
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Abstract
PURPOSE OF REVIEW Colonization of the host epithelia by pathogenic Escherichia coli is influenced by the ability of the bacteria to interact with host surfaces. Because the initial step of an E. coli infection is to adhere, invade, and persist within host cells, some strategies used by intestinal and extraintestinal E. coli to infect host cell are presented. RECENT FINDINGS This review highlights recent progress understanding how extraintestinal pathogenic E. coli strains express specific adhesins or invasins that allow colonization of the urinary tract or the meninges, while intestinal E. coli strains are able to colonize different regions of the intestinal tract using other specialized adhesins or invasins. Finally, evaluation of different diets and environmental conditions regulating the colonization of these pathogens is discussed. SUMMARY Discovery of new interactions between pathogenic E. coli and the host epithelial cells unravels the need for more mechanistic studies that can provide new clues regarding how to combat these infections.
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25
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Valeri M, Rossi Paccani S, Kasendra M, Nesta B, Serino L, Pizza M, Soriani M. Pathogenic E. coli exploits SslE mucinase activity to translocate through the mucosal barrier and get access to host cells. PLoS One 2015; 10:e0117486. [PMID: 25789808 DOI: 10.1371/journal.pone.0117486] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Accepted: 12/24/2014] [Indexed: 12/27/2022] Open
Abstract
SslE is a zinc-metalloprotease involved in the degradation of mucin substrates and recently proposed as a potential vaccine candidate against pathogenic E. coli. In this paper, by exploiting a human in vitro model of mucus-secreting cells, we demonstrated that bacteria expressing SslE have a metabolic benefit which results in an increased growth rate postulating the importance of this antigen in enhancing E. coli fitness. We also observed that SslE expression facilitates E. coli penetration of the mucus favouring bacteria adhesion to host cells. Moreover, we found that SslE-mediated opening of the mucosae contributed to the activation of pro-inflammatory events. Indeed, intestinal cells infected with SslE-secreting bacteria showed an increased production of IL-8 contributing to neutrophil recruitment. The results presented in this paper conclusively designate SslE as an important colonization factor favouring E. coli access to both metabolic substrates and target cells.
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Affiliation(s)
- Maria Valeri
- Novartis Vaccines and Diagnostics S.r.l., Via Fiorentina 1, Siena, Italy
| | | | - Magdalena Kasendra
- Children's Hospital Boston, Harvard Medical School, 200 Longwood Avenue, Boston, Massachusetts 02115, United States of America
| | - Barbara Nesta
- Novartis Vaccines and Diagnostics S.r.l., Via Fiorentina 1, Siena, Italy
| | - Laura Serino
- Novartis Vaccines and Diagnostics S.r.l., Via Fiorentina 1, Siena, Italy
| | - Mariagrazia Pizza
- Novartis Vaccines and Diagnostics S.r.l., Via Fiorentina 1, Siena, Italy
| | - Marco Soriani
- Novartis Vaccines and Diagnostics S.r.l., Via Fiorentina 1, Siena, Italy
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Influence of environmental factors in the adherence of an atypical enteropathogenic Escherichia coli strain to epithelial cells. BMC Microbiol 2014; 14:299. [PMID: 25527183 PMCID: PMC4290818 DOI: 10.1186/s12866-014-0299-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Accepted: 11/18/2014] [Indexed: 11/10/2022] Open
Abstract
Background Attachment is essential to maintain bacteria at their preferential intestinal colonization sites. There is little information on the influence of different environmental conditions in the interaction of atypical enteropathogenic Escherichia coli (aEPEC) strains with epithelial cells. In this study, we evaluated the effect of different glucose (5 and 25 mM) and CO2 (0.03 and 5%) concentrations and presence of bile salts on the adhesiveness of the aEPEC strain 1551–2. Results We found that a CO2-enriched atmosphere enhanced the adhesiveness of the aEPEC 1551–2 strain independently of glucose concentrations or presence of bile salts. Conversely, the presence of high glucose concentration altered the original localized adherence (LA) pattern observed at 5 mM glucose, which is characterized by the formation of compact bacterial clusters, to a hybrid adherence pattern (LA and an aggregative adherence-like pattern). In addition, at high glucose concentration, there was increased expression of the fimA gene, which encodes the major subunit of type 1 pilus (T1P), and an isogenic fimA mutant displayed only LA. The presence of bile salts did not interfere with the adhesion properties of the 1551–2 strain to HeLa cells. Conclusions Our data suggest that a CO2-enriched atmosphere could favor aEPEC adhesion to the host cells, whereas enhanced T1P production under high glucose concentration could allow bacteria to access more extensive intestinal colonization sites in the host at the beginning of the infectious process.
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Pitondo-Silva A, Nakazato G, Falcão JP, Irino K, Martinez R, Darini ALC, Hernandes RT. Phenotypic and genetic features of enteropathogenic Escherichia coli isolates from diarrheal children in the Ribeirão Preto metropolitan area, São Paulo State, Brazil. APMIS 2014; 123:128-35. [PMID: 25257819 DOI: 10.1111/apm.12314] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Accepted: 07/25/2014] [Indexed: 12/01/2022]
Abstract
This study was designed to characterize a collection of 60 enteropathogenic Escherichia coli (EPEC) isolates from diarrheic feces of patients in the Ribeirão Preto metropolitan area regarding different phenotypic and molecular features. We examined antibiotic resistance profiles, occurrence of virulence factors-encoding genes, intimin subtypes and the correlation of serotypes among typical (tEPEC) and atypical (aEPEC) EPEC isolates. The results demonstrated that atypical EPEC was more heterogeneous than typical EPEC concerning the characteristics investigated and 45.2% do not belong to classical EPEC serogroups. Intimin subtype β was the most frequent among the EPEC isolates (46.7%), being detected in both tEPEC and aEPEC. The majority of aEPEC isolates presented localized adherence-like (LAL) pattern to HEp-2 cells, although aEPEC isolates displaying diffuse adherence (DA) or non-adherent were also detected. High prevalence of antimicrobial resistance was found for ampicillin, cephalothin, sulfonamide and tetracycline. In general, tEPEC isolates were more resistant to the antimicrobials tested than aEPEC isolates.
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Affiliation(s)
- André Pitondo-Silva
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo (USP), Ribeirão Preto, São Paulo, Brazil
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Nascimento HH, Silva LEP, Souza RT, Silva NP, Scaletsky ICA. Phenotypic and genotypic characteristics associated with biofilm formation in clinical isolates of atypical enteropathogenic Escherichia coli (aEPEC) strains. BMC Microbiol 2014; 14:184. [PMID: 25012525 PMCID: PMC4100040 DOI: 10.1186/1471-2180-14-184] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Accepted: 07/04/2014] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Biofilm formation by enteropathogenic Escherichia coli (EPEC) have been recently described in the prototype typical EPEC E2348/69 strain and in an atypical EPEC O55:H7 strain. In this study, we sought to evaluate biofilm formation in a collection of 126 atypical EPEC strains isolated from 92 diarrheic and 34 nondiarrheic children, belonging to different serotypes. The association of biofilm formation and adhesin-related genes were also investigated. RESULTS Biofilm formation occurred in 37 (29%) strains of different serotypes, when the assays were performed at 26°C and 37°C for 24 h. Among these, four strains (A79, A87, A88, and A111) formed a stronger biofilm than did the others. The frequency of biofilm producers was higher among isolates from patients compared with isolates from controls (34.8% vs 14.7%; P = 0.029). An association was found between biofilm formation and expression of type 1 fimbriae and curli (P < 0.05). Unlike the previously described aEPEC O55:H7, one aEPEC O119:HND strain (A111) formed a strong biofilm and pellicle at the air-liquid interface, but did not express curli. Transposon mutagenesis was used to identify biofilm-deficient mutants. Transposon insertion sequences of six mutants revealed similarity with type 1 fimbriae (fimC, fimD, and fimH), diguanylate cyclase, ATP synthase F1, beta subunit (atpD), and the uncharacterized YjiC protein. All these mutants were deficient in biofilm formation ability. CONCLUSION This study showed that the ability to adhere to abiotic surfaces and form biofilm is present in an array of aEPEC strains. Moreover, it seems that the ability to form biofilms is associated with the presence of type 1 fimbriae and diguanylate cyclase. Characterization of additional biofilm formation mutants may reveal other mechanisms involved in biofilm formation and bring new insights into aEPEC adhesion and pathogenesis.
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Affiliation(s)
| | | | | | | | - Isabel C A Scaletsky
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, Rua Botucatu, 862, 3 andar, 04023-062 São Paulo, Brazil.
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Nesta B, Valeri M, Spagnuolo A, Rosini R, Mora M, Donato P, Alteri CJ, Del Vecchio M, Buccato S, Pezzicoli A, Bertoldi I, Buzzigoli L, Tuscano G, Falduto M, Rippa V, Ashhab Y, Bensi G, Fontana MR, Seib KL, Mobley HLT, Pizza M, Soriani M, Serino L. SslE elicits functional antibodies that impair in vitro mucinase activity and in vivo colonization by both intestinal and extraintestinal Escherichia coli strains. PLoS Pathog 2014; 10:e1004124. [PMID: 24809621 PMCID: PMC4014459 DOI: 10.1371/journal.ppat.1004124] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Accepted: 03/31/2014] [Indexed: 11/18/2022] Open
Abstract
SslE, the Secreted and surface-associated lipoprotein from Escherichia coli, has recently been associated to the M60-like extracellular zinc-metalloprotease sub-family which is implicated in glycan recognition and processing. SslE can be divided into two main variants and we recently proposed it as a potential vaccine candidate. By applying a number of in vitro bioassays and comparing wild type, knockout mutant and complemented strains, we have now demonstrated that SslE specifically contributes to degradation of mucin substrates, typically present in the intestine and bladder. Mutation of the zinc metallopeptidase motif of SslE dramatically impaired E. coli mucinase activity, confirming the specificity of the phenotype observed. Moreover, antibodies raised against variant I SslE, cloned from strain IHE3034 (SslEIHE3034), are able to inhibit translocation of E. coli strains expressing different variants through a mucin-based matrix, suggesting that SslE induces cross-reactive functional antibodies that affect the metallopeptidase activity. To test this hypothesis, we used well-established animal models and demonstrated that immunization with SslEIHE3034 significantly reduced gut, kidney and spleen colonization by strains producing variant II SslE and belonging to different pathotypes. Taken together, these data strongly support the importance of SslE in E. coli colonization of mucosal surfaces and reinforce the use of this antigen as a component of a broadly protective vaccine against pathogenic E. coli species. Escherichia coli are the predominant facultative anaerobe of the human colonic flora. Although intestinal and extraintestinal pathogenic E. coli are phylogenetically and epidemiologically distinct, we recently proposed a number of protective antigens conserved in most E. coli pathotypes. In this study, we have elucidated the function of the most promising of these antigens, SslE, which is characterized by the presence of a M60-like domain representative of a new extracellular zinc-metalloprotease sub-family. In particular, in vitro analysis of the ability of an sslE knockout mutant strain to transverse an agar-based mucin matrix revealed that SslE is essential to E. coli mucinase activity. Evidence showing that SslE induces functional antibodies, preventing both in vitro mucin degradation but also in vivo gut, kidney and spleen colonization, further support the hypothesis that SslE may facilitate E. coli colonization by favoring the penetration of the sterile inner mucus layer leading to interaction with host cells. Finally, the ability of SslE to also induce protective immunity against sepsis, linked to its presence among different pathotypes, supports the use of such an antigen as a broadly protective E. coli vaccine candidate.
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Affiliation(s)
| | - Maria Valeri
- Novartis Vaccines and Diagnostics Srl, Siena, Italy
| | | | | | | | - Paolo Donato
- Novartis Vaccines and Diagnostics Srl, Siena, Italy
| | - Christopher J. Alteri
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | | | | | | | | | | | | | | | | | - Yaqoub Ashhab
- Biotechnology Research Center, Palestine Polytechnic University, Hebron, Palestine
| | | | | | - Kate L. Seib
- Institute for Glycomics, Griffith University, Gold Coast Campus, Queensland, Australia
| | - Harry L. T. Mobley
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | | | - Marco Soriani
- Novartis Vaccines and Diagnostics Srl, Siena, Italy
- * E-mail:
| | - Laura Serino
- Novartis Vaccines and Diagnostics Srl, Siena, Italy
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