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Mignini I, Blasi V, Termite F, Esposto G, Borriello R, Laterza L, Scaldaferri F, Ainora ME, Gasbarrini A, Zocco MA. Fibrostenosing Crohn's Disease: Pathogenetic Mechanisms and New Therapeutic Horizons. Int J Mol Sci 2024; 25:6326. [PMID: 38928032 PMCID: PMC11204249 DOI: 10.3390/ijms25126326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 05/30/2024] [Accepted: 06/04/2024] [Indexed: 06/28/2024] Open
Abstract
Bowel strictures are well recognized as one of the most severe complications in Crohn's disease, with variable impacts on the prognosis and often needing surgical or endoscopic treatment. Distinguishing inflammatory strictures from fibrotic ones is of primary importance due to the different therapeutic approaches required. Indeed, to better understand the pathogenesis of fibrosis, it is crucial to investigate molecular processes involving genetic factors, cytokines, alteration of the intestinal barrier, and epithelial and endothelial damage, leading to an increase in extracellular matrix synthesis, which ultimately ends in fibrosis. In such a complex mechanism, the gut microbiota also seems to play a role. A better comprehension of molecular processes underlying bowel fibrosis, in addition to radiological and histopathological findings, has led to the identification of high-risk patients for personalized follow-up and testing of new therapies, primarily in preclinical models, targeting specific pathways involving Transforming Growth Factor-β, interleukins, extracellular matrix balance, and gut microbiota. Our review aims to summarize current evidence about molecular factors involved in intestinal fibrosis' pathogenesis, paving the way for potential diagnostic biomarkers or anti-fibrotic treatments for stricturing Crohn's disease.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Maria Assunta Zocco
- CEMAD Digestive Diseases Center, Fondazione Policlinico Universitario “A. Gemelli” IRCCS, Università Cattolica del Sacro Cuore, Largo A. Gemelli 8, 00168 Rome, Italy; (I.M.); (V.B.); (G.E.); (R.B.); (L.L.); (F.S.); (M.E.A.); (A.G.)
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Miyagi K, Shimoji N, Oshiro H, Hirai I. Differences in flaA gene sequences, swimming motility, and biofilm forming ability between clinical and environmental isolates of Aeromonas species. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:11740-11754. [PMID: 36098923 DOI: 10.1007/s11356-022-22871-7] [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: 07/05/2022] [Accepted: 08/31/2022] [Indexed: 06/15/2023]
Abstract
The flagellin A gene (flaA) sequences, swimming motility, and biofilm forming ability were investigated in order to reveal the genetic and functional differences of flagella between clinical and environmental isolates of Aeromonas species. Twenty-eight clinical and 48 environmental strains of Aeromonas species isolated in Okinawa Prefecture of Japan were used in this study. The full-length flaA genes of these strains were sequenced and aligned, and a phylogenetic tree was constructed. In addition, swimming motility and biofilm forming ability were evaluated by conventional methods. Aeromonas veronii biovar sobria and A. hydrophila clearly divided into clinical and environmental strain clusters in the flaA phylogenetic classification, and the six and 13 specific amino acids respectively, of FlaA of both species were different in clinical and environmental strains. Furthermore, the flaA size of the clinical strain of A. veronii bv. sobria was mainly 909, 924, and 939 bp, and the size of A. hydrophila was 909 bp. The swimming motility of clinical isolates of both species was lower than the environmental isolates; however, the biofilm forming ability of the clinical isolates was high. Thus, the clinical isolates of A. veronii bv. sobria and A. hydrophila had different genetic and functional characteristics of flagellin than the environmental isolates. The characteristics of flagellin could serve as indicators to distinguish between clinical and environmental isolates of the both species. It may contribute to diagnosis of these diseases and the monitoring of clinical strain invasion into the natural environment.
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Affiliation(s)
- Kazufumi Miyagi
- Laboratory of Microbiology, School of Health Sciences, Faculty of Medicine, University of the Ryukyus, 207 Uehara, Nishihara-cho, Okinawa, 903-0215, Japan.
| | - Noriaki Shimoji
- Department of Clinical Laboratory, Urasoe General Hospital, 4-16-1 Iso, Urasoe-shi, Okinawa, 901-2132, Japan
| | - Haruna Oshiro
- Department of Clinical Laboratory, Urasoe General Hospital, 4-16-1 Iso, Urasoe-shi, Okinawa, 901-2132, Japan
| | - Itaru Hirai
- Laboratory of Microbiology, School of Health Sciences, Faculty of Medicine, University of the Ryukyus, 207 Uehara, Nishihara-cho, Okinawa, 903-0215, Japan
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3
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Ouyang J, Yan J, Zhou X, Isnard S, Harypursat V, Cui H, Routy JP, Chen Y. Relevance of biomarkers indicating gut damage and microbial translocation in people living with HIV. Front Immunol 2023; 14:1173956. [PMID: 37153621 PMCID: PMC10160480 DOI: 10.3389/fimmu.2023.1173956] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Accepted: 04/10/2023] [Indexed: 05/10/2023] Open
Abstract
The intestinal barrier has the daunting task of allowing nutrient absorption while limiting the entry of microbial products into the systemic circulation. HIV infection disrupts the intestinal barrier and increases intestinal permeability, leading to microbial product translocation. Convergent evidence has shown that gut damage and an enhanced level of microbial translocation contribute to the enhanced immune activation, the risk of non-AIDS comorbidity, and mortality in people living with HIV (PLWH). Gut biopsy procedures are invasive, and are not appropriate or feasible in large populations, even though they are the gold standard for intestinal barrier investigation. Thus, validated biomarkers that measure the degree of intestinal barrier damage and microbial translocation are needed in PLWH. Hematological biomarkers represent an objective indication of specific medical conditions and/or their severity, and should be able to be measured accurately and reproducibly via easily available and standardized blood tests. Several plasma biomarkers of intestinal damage, i.e., intestinal fatty acid-binding protein (I-FABP), zonulin, and regenerating islet-derived protein-3α (REG3α), and biomarkers of microbial translocation, such as lipopolysaccharide (LPS) and (1,3)-β-D-Glucan (BDG) have been used as markers of risk for developing non-AIDS comorbidities in cross sectional analyses and clinical trials, including those aiming at repair of gut damage. In this review, we critically discuss the value of different biomarkers for the estimation of gut permeability levels, paving the way towards developing validated diagnostic and therapeutic strategies to repair gut epithelial damage and to improve overall disease outcomes in PLWH.
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Affiliation(s)
- Jing Ouyang
- Department of Infectious Diseases, Chongqing Public Health Medical Center, Chongqing, China
- Clinical Research Center, Chongqing Public Health Medical Center, Chongqing, China
| | - Jiangyu Yan
- Department of Infectious Diseases, Chongqing Public Health Medical Center, Chongqing, China
- Clinical Research Center, Chongqing Public Health Medical Center, Chongqing, China
| | - Xin Zhou
- Clinical Research Center, Chongqing Public Health Medical Center, Chongqing, China
- Cancer Center, Medical Research Institute, Southwest University, Chongqing, China
| | - Stéphane Isnard
- Infectious Diseases and Immunity in Global Health Program, Research Institute, McGill University Health Centre, Montréal, QC, Canada
- Chronic Viral Illness Service, McGill University Health Centre, Montréal, QC, Canada
- Canadian HIV Trials Network, Canadian Institutes for Health Research, Vancouver, BC, Canada
| | - Vijay Harypursat
- Department of Infectious Diseases, Chongqing Public Health Medical Center, Chongqing, China
- Clinical Research Center, Chongqing Public Health Medical Center, Chongqing, China
| | - Hongjuan Cui
- Cancer Center, Medical Research Institute, Southwest University, Chongqing, China
| | - Jean-Pierre Routy
- Infectious Diseases and Immunity in Global Health Program, Research Institute, McGill University Health Centre, Montréal, QC, Canada
- Chronic Viral Illness Service, McGill University Health Centre, Montréal, QC, Canada
- Division of Hematology, McGill University Health Centre, Montréal, QC, Canada
- *Correspondence: Jean-Pierre Routy, ; Yaokai Chen,
| | - Yaokai Chen
- Department of Infectious Diseases, Chongqing Public Health Medical Center, Chongqing, China
- *Correspondence: Jean-Pierre Routy, ; Yaokai Chen,
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Genotyping of Burkholderia pseudomallei Isolated From Patients in South-Western Coastal Region of India. Curr Microbiol 2022; 79:226. [PMID: 35731378 DOI: 10.1007/s00284-022-02905-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Accepted: 05/16/2022] [Indexed: 11/03/2022]
Abstract
Burkholderia pseudomallei is the causative agent of melioidosis. Various tools have been used to determine the genetic diversity in B. pseudomallei isolates. In this study, Random Amplified Polymorphic DNA (RAPD)-PCR and flagellin gene (fliC) based PCR-Restriction Fragment Length Polymorphism (RFLP) were used to genotype Indian clinical B. pseudomallei isolates. A total of 89 clinical isolates could be grouped in 6 groups (A through F) by RAPD-PCR analysis. Some of the isolates in various groups had identical banding pattern suggesting them to be epidemiologically related. The RAPD groups also correlated with MLST sequence types suggesting the utility of this easy to do typing method. The PCR- RFLP analysis suggested Type III to be the predominant type which is different from other RFLP types reported from Southeast Asia. In conclusion, the results of this study show that RAPD-PCR, a simple genotyping method, may be used for analyzing the B. pseudomallei isolates and also establish epidemiological relevant relatedness among them. The results of fliC PCR-RFLP further suggest the Indian isolates are different from other Southeast Asian isolates.
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5
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Watanabe D, Kamada N. Contribution of the Gut Microbiota to Intestinal Fibrosis in Crohn's Disease. Front Med (Lausanne) 2022; 9:826240. [PMID: 35198577 PMCID: PMC8859331 DOI: 10.3389/fmed.2022.826240] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 01/13/2022] [Indexed: 12/16/2022] Open
Abstract
In Crohn's disease (CD), intestinal fibrosis is a critical determinant of a patient's prognosis. Although inflammation may be a prerequisite for the initiation of intestinal fibrosis, research shows that the progression or continuation of intestinal fibrosis can occur independently of inflammation. Thus, once initiated, intestinal fibrosis may persist even if medical treatment controls inflammation. Clearly, an understanding of the pathophysiological mechanisms of intestinal fibrosis is required to diminish its occurrence. Accumulating evidence suggests that the gut microbiota contributes to the pathogenesis of intestinal fibrosis. For example, the presence of antibodies against gut microbes can predict which CD patients will have intestinal complications. In addition, microbial ligands can activate intestinal fibroblasts, thereby inducing the production of extracellular matrix. Moreover, in various animal models, bacterial infection can lead to the development of intestinal fibrosis. In this review, we summarize the current knowledge of the link between intestinal fibrosis in CD and the gut microbiota. We highlight basic science and clinical evidence that the gut microbiota can be causative for intestinal fibrosis in CD and provide valuable information about the animal models used to investigate intestinal fibrosis.
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Affiliation(s)
- Daisuke Watanabe
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI, United States
| | - Nobuhiko Kamada
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI, United States
- WPI Immunology Frontier Research Center, Osaka University, Suita, Japan
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6
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Hu D, Fuller NR, Caterson ID, Holmes AJ, Reeves PR. Single-gene long-read sequencing illuminates Escherichia coli strain dynamics in the human intestinal microbiome. Cell Rep 2022; 38:110239. [PMID: 35021078 DOI: 10.1016/j.celrep.2021.110239] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 10/17/2021] [Accepted: 12/17/2021] [Indexed: 02/01/2023] Open
Abstract
Gut microbiome is of major interest due to its close relationship to health and disease. Bacteria usually vary in gene content, leading to functional variations within species, so resolution higher than species-level methods is needed for ecological and clinical relevance. We design a protocol to identify strains in selected species with high discrimination and in high numbers by amplicon sequencing of the flagellin gene. We apply the protocol to fecal samples from a human diet trial, targeting Escherichia coli. Across the 119 samples from 16 individuals, there are 1,532 amplicon sequence variants (ASVs), but only 32 ASVs are dominant in one or more fecal samples, despite frequent dominant strain turnover. Major strains in an intestine are found to be commonly accompanied by a large number of satellite cells, and many are identified as potential extraintestinal pathogens. The protocol could be used to track epidemics or investigate the intra- or inter-host diversity of pathogens.
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Affiliation(s)
- Dalong Hu
- School of Life and Environmental Sciences, Charles Perkins Centre, University of Sydney, Camperdown, NSW 2006, Australia
| | - Nicholas R Fuller
- The Boden Institute, Charles Perkins Centre, University of Sydney, Camperdown, NSW 2006, Australia; Metabolism and Obesity Services, Royal Prince Alfred Hospital, Camperdown, NSW 2050, Australia
| | - Ian D Caterson
- School of Life and Environmental Sciences, Charles Perkins Centre, University of Sydney, Camperdown, NSW 2006, Australia; The Boden Institute, Charles Perkins Centre, University of Sydney, Camperdown, NSW 2006, Australia; Metabolism and Obesity Services, Royal Prince Alfred Hospital, Camperdown, NSW 2050, Australia
| | - Andrew J Holmes
- School of Life and Environmental Sciences, Charles Perkins Centre, University of Sydney, Camperdown, NSW 2006, Australia
| | - Peter R Reeves
- School of Life and Environmental Sciences, Charles Perkins Centre, University of Sydney, Camperdown, NSW 2006, Australia.
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7
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Lack of N-Terminal Segment of the Flagellin Protein Results in the Production of a Shortened Polar Flagellum in the Deep-Sea Sedimentary Bacterium Pseudoalteromonas sp. Strain SM9913. Appl Environ Microbiol 2021; 87:e0152721. [PMID: 34406825 DOI: 10.1128/aem.01527-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacterial polar flagella, comprised of flagellin, are essential for bacterial motility. Pseudoalteromonas sp. strain SM9913 is a bacterium isolated from deep-sea sediments. Unlike other Pseudoalteromonas strains that have a long polar flagellum, strain SM9913 has an abnormally short polar flagellum. Here, we investigated the underlying reason for the short flagellum and found that a single-base mutation was responsible for the altered flagellar assembly. This mutation leads to the fragmentation of the flagellin gene into two genes, PSM_A2281, encoding the core segment and the C-terminal segment, and PSM_A2282, encoding the N-terminal segment, and only gene PSM_A2281 is involved in the production of the short polar flagellum. When a chimeric gene of PSM_A2281 and PSM_A2282 encoding an intact flagellin, A2281::82, was expressed, a long polar flagellum was produced, indicating that the N-terminal segment of flagellin contributes to the production of a polar flagellum of a normal length. Analyses of the simulated structures of A2281 and A2281::82 and that of the flagellar filament assembled with A2281::82 indicate that due to the lack of two α-helices, the core of the flagellar filament assembled with A2281 is incomplete and is likely too weak to support the stability and movement of a long flagellum. This mutation in strain SM9913 had little effect on its growth and only a small effect on its swimming motility, implying that strain SM9913 can live well with this mutation in natural sedimentary environments. This study provides a better understanding of the assembly and production of bacterial flagella. IMPORTANCE Polar flagella, which are essential organelles for bacterial motility, are comprised of multiple flagellin subunits. A flagellin molecule contains an N-terminal segment, a core segment, and a C-terminal segment. The results of this investigation of the deep-sea sedimentary bacterium Pseudoalteromonas sp. strain SM9913 demonstrate that a single-base mutation in the flagellin gene leads to the production of an incomplete flagellin without the N-terminal segment and that the loss of the N-terminal segment of the flagellin protein results in the production of a shortened polar flagellar filament. Our results shed light on the important function of the N-terminal segment of flagellin in the assembly and stability of bacterial flagellar filament.
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Rogé AD, Celi Castillo AB, van der Ploeg CA, Bordagorría XL, Padín VM, Bruno SB. Identification of Two New Sequences of Flagellin-Encoding Gene in Escherichia coli Using PCR and Sequencing-Based Methods. Foodborne Pathog Dis 2021; 19:31-35. [PMID: 34491107 DOI: 10.1089/fpd.2021.0033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Escherichia coli has traditionally been serotyped using antisera against the O and H antigens. However, a proportion of E. coli isolates are nonmotile and, in addition, some isolates do not react with the currently available H-typing sera. Alternative molecular methods have been developed based on the detection of genes encoding for H antigens. In this study, we studied 13 serologically nontypable H antigen E. coli strains using polymerase chain reaction (PCR) and sequencing-based methods. We found two new sequences of flagellin-encoding gene, for each of which a specific antiserum was produced to confirm their expression. Sequencing of the flagellin gene offers a rapid determination of E. coli H antigens and could be used to detect potential novel flagellar antigens.
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Affiliation(s)
- Ariel Diego Rogé
- Servicio Antígenos y Antisueros, Instituto Nacional de Producción de Biológicos, ANLIS "Dr. Carlos G. Malbrán," Ciudad Autónoma de Buenos Aires, Argentina
| | - Ana Beatriz Celi Castillo
- Servicio Antígenos y Antisueros, Instituto Nacional de Producción de Biológicos, ANLIS "Dr. Carlos G. Malbrán," Ciudad Autónoma de Buenos Aires, Argentina
| | - Claudia Andrea van der Ploeg
- Servicio Antígenos y Antisueros, Instituto Nacional de Producción de Biológicos, ANLIS "Dr. Carlos G. Malbrán," Ciudad Autónoma de Buenos Aires, Argentina
| | - Ximena Luciana Bordagorría
- Servicio Antígenos y Antisueros, Instituto Nacional de Producción de Biológicos, ANLIS "Dr. Carlos G. Malbrán," Ciudad Autónoma de Buenos Aires, Argentina
| | - Valeria M Padín
- Servicio Antígenos y Antisueros, Instituto Nacional de Producción de Biológicos, ANLIS "Dr. Carlos G. Malbrán," Ciudad Autónoma de Buenos Aires, Argentina
| | - Susana Beatriz Bruno
- Servicio Antígenos y Antisueros, Instituto Nacional de Producción de Biológicos, ANLIS "Dr. Carlos G. Malbrán," Ciudad Autónoma de Buenos Aires, Argentina
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Insights into Autotrophic Activities and Carbon Flow in Iron-Rich Pelagic Aggregates (Iron Snow). Microorganisms 2021; 9:microorganisms9071368. [PMID: 34201891 PMCID: PMC8305228 DOI: 10.3390/microorganisms9071368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 06/18/2021] [Accepted: 06/21/2021] [Indexed: 11/17/2022] Open
Abstract
Pelagic aggregates function as biological carbon pumps for transporting fixed organic carbon to sediments. In iron-rich (ferruginous) lakes, photoferrotrophic and chemolithoautotrophic bacteria contribute to CO2 fixation by oxidizing reduced iron, leading to the formation of iron-rich pelagic aggregates (iron snow). The significance of iron oxidizers in carbon fixation, their general role in iron snow functioning and the flow of carbon within iron snow is still unclear. Here, we combined a two-year metatranscriptome analysis of iron snow collected from an acidic lake with protein-based stable isotope probing to determine general metabolic activities and to trace 13CO2 incorporation in iron snow over time under oxic and anoxic conditions. mRNA-derived metatranscriptome of iron snow identified four key players (Leptospirillum, Ferrovum, Acidithrix, Acidiphilium) with relative abundances (59.6-85.7%) encoding ecologically relevant pathways, including carbon fixation and polysaccharide biosynthesis. No transcriptional activity for carbon fixation from archaea or eukaryotes was detected. 13CO2 incorporation studies identified active chemolithoautotroph Ferrovum under both conditions. Only 1.0-5.3% relative 13C abundances were found in heterotrophic Acidiphilium and Acidocella under oxic conditions. These data show that iron oxidizers play an important role in CO2 fixation, but the majority of fixed C will be directly transported to the sediment without feeding heterotrophs in the water column in acidic ferruginous lakes.
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Abstract
Bacterial and archaeal flagellins are remarkable in having a shared region with variation in housekeeping proteins and a region with extreme diversity, perhaps greater than for any other protein. Analysis of the 113,285 available full-gene sequences of flagellin genes from published bacterial and archaeal sequences revealed the nature and enormous extent of flagellin diversity. There were 35,898 unique amino acid sequences that were resolved into 187 clusters. Analysis of the Escherichia coli and Salmonella enterica flagellins revealed that the variation occurs at two levels. The first is the division of the variable regions into sequence forms that are so divergent that there is no meaningful alignment even within species, and these corresponded to the E. coli or S. enterica H-antigen groups. The second level is variation within these groups, which is extensive in both species. Shared sequence would allow PCR of the variable regions and thus strain-level analysis of microbiome DNA. Flagellin, the agent of prokaryotic flagellar motion, is very widely distributed and is the H antigen of serology. Flagellin molecules have a variable region that confers serotype specificity, encoded by the middle of the gene, and also conserved regions encoded by the two ends of the gene. We collected all available prokaryotic flagellin protein sequences and found the variable region diversity to be at two levels. In each species investigated, there are hypervariable region (HVR) forms without detectable homology in protein sequences between them. There is also considerable variation within HVR forms, indicating that some have been diverging for thousands of years and that interphylum horizontal gene transfers make a major contribution to the evolution of such atypical diversity. IMPORTANCE Bacterial and archaeal flagellins are remarkable in having a shared region with variation in housekeeping proteins and a region with extreme diversity, perhaps greater than for any other protein. Analysis of the 113,285 available full-gene sequences of flagellin genes from published bacterial and archaeal sequences revealed the nature and enormous extent of flagellin diversity. There were 35,898 unique amino acid sequences that were resolved into 187 clusters. Analysis of the Escherichia coli and Salmonella enterica flagellins revealed that the variation occurs at two levels. The first is the division of the variable regions into sequence forms that are so divergent that there is no meaningful alignment even within species, and these corresponded to the E. coli or S. enterica H-antigen groups. The second level is variation within these groups, which is extensive in both species. Shared sequence would allow PCR of the variable regions and thus strain-level analysis of microbiome DNA.
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Signatures of balancing selection in toll-like receptor (TLRs) genes - novel insights from a free-living rodent. Sci Rep 2018; 8:8361. [PMID: 29849060 PMCID: PMC5976762 DOI: 10.1038/s41598-018-26672-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 05/15/2018] [Indexed: 01/12/2023] Open
Abstract
Selective pressure from pathogens is considered a key selective force driving the evolution of components of the immune system. Since single components of the immune system may interact with many pathogens, and single pathogens may be recognized by multiple components of the immune system, gaining a better understanding of the mechanisms of parasite-driven selection requires the study of multiple genes and pathogens. Toll-like receptors (TLRs) are a large gene family that code for antigen-presenting components of the innate immune response. In the present paper we characterize polymorphism and signatures of selection in seven TLRs in free-living bank voles Myodes glareolus. We report the first evidence of balancing selection in several TLR genes, supported by positive values of Fu and Li's D* in TLR2 and TLR5, and positive values of Tajima's D in LRR regions within TLR1 and TLR2. We further found significant associations between amino-acid alleles of TLR1 and TLR5 and susceptibility to infection with the blood pathogen Bartonella. Interestingly, selection patterns in TLRs presenting virus-derived motifs (TLR7 and TLR9) differed considerably from those interacting with bacterial PAMPs. In contrast to the highly variable TLRs presenting bacterial motifs, TLR7 and TLR9 had low polymorphism and displayed signatures of directional selection. These findings suggest different functional responses across the TLR gene family and highlight the complexity of parasite-driven selection.
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Bakhshi B, Dehghan-Mouriaabadi A, Kiani P. Heterogeneity of Multidrug-Resistant Salmonella enterica Isolates with Increasing Frequency of Resistance to Ciprofloxacin During a 4-Year Period in Iran. Microb Drug Resist 2018; 24:479-488. [PMID: 29293397 DOI: 10.1089/mdr.2017.0135] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND The study was conducted to assess the trend of antimicrobial resistance among Salmonella enterica strains during a period of 4 years and to compare the effectiveness of three genotyping methods, including flagellin polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP), enterobacterial repetitive intergenic consensus (ERIC)-PCR, and pulsed-field gel electrophoresis (PFGE), and to determine the most efficient method for S. enterica genotyping. METHODS AND RESULTS About 50 S. enterica isolates were isolated from 5,064 stool samples. All of the isolates harbored fliC gene, 29 of which (58%) showed diphasic characteristic with a fliC+/fljB+ genotype. Simpson diversity index (Di) for RFLP analysis of fliC and fljB genes was calculated as 0.71 and 0.82, respectively. Strains were differentiated into 40 ERIC genotypes and 27 pulsotypes. All isolates with identical pulsotypes belonged to common serogroups which depict their correlation in a good manner. The Di calculated for ERIC-PCR and PFGE analysis was 0.99 and 0.94, respectively. The frequency of multidrug resistance (MDR) was dramatically increased from 25% in 2009-2010 to 63% in 2011-2012 with the emergence of 10% ciprofloxacin resistance in the latter period. CONCLUSION About 44% increase in MDR phenotype among S. enterica isolates during a 4-year period and concomitant appearance of ciprofloxacin resistance is a traumatic situation for health professionals in Iran. PFGE profiles offered a satisfactory discriminatory power, which was positively correlated with S. enterica serogrouping. The current study marks the superiority of PFGE method over other conventional molecular techniques in epidemiological investigations; however, their limitations need to be addressed for further refinement.
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Affiliation(s)
- Bita Bakhshi
- 1 Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University , Tehran, Iran
| | | | - Parisa Kiani
- 1 Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University , Tehran, Iran
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Host Specificity of Flagellins from Segmented Filamentous Bacteria Affects Their Patterns of Interaction with Mouse Ileal Mucosal Proteins. Appl Environ Microbiol 2017; 83:AEM.01061-17. [PMID: 28687648 DOI: 10.1128/aem.01061-17] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 06/26/2017] [Indexed: 11/20/2022] Open
Abstract
Segmented filamentous bacteria (SFB) are known modulators of the mammalian immune system. Currently, the technology for investigating SFB culture in vitro is immature, and as a result, the mechanisms of SFB colonization and immune regulation are not yet fully elucidated. In this study, we investigated the gene diversity and host specificity of SFB flagellin genes. The fliC1 and fliC2 genes are relatively conserved, while the fliC3 and fliC4 genes are more variable, especially at the central and C-terminal regions. Host specificity analysis demonstrated that the fliC1 genes do not cluster together based on the host organism, whereas the fliC3 and fliC4 genes were host specific at the nucleotide and deduced amino acid levels. SFB flagellin protein expression in the ileum mucosa and cecal contents was detected by using fluorescence in situ hybridization (FISH) combined with immunohistochemical (IHC) analysis, immunoblotting, and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Although the purified SFB FliC3 protein originating from both mouse and rat was able to activate Toll-like receptor 5 (TLR5)-linked NF-κB signaling, no host specificity was observed. Interestingly, the patterns of interaction with mouse ileum mucosal proteins were different for mouse FliC3 (mFliC3) and rat FliC3 (rFliC3). Gene Ontology (GO) and KEGG analyses indicated that more adherence-related proteins interacted with mFliC3, while more lysosome- and proteolysis-related proteins interacted with rFliC3. In vitro degradation experiments indicated that the stability of rFliC3 was lower than that of mFliC3 when they were incubated with mouse ileum mucosal proteins. In summary, the gene diversity and host specificity of SFB flagellin genes were investigated, and SFB flagellin expression was detected in gut samples.IMPORTANCE Since SFB genomes contain only one copy of each FliC gene, the diversity of FliC is representative of SFB strain diversity. Currently, little is known regarding the diversity and specificity of members of the group of SFB. The work presented herein demonstrates that select SFB strains, exhibiting unique FliC patterns, are present in a variety of mammalian hosts. SFB fliC genes were found to interact with a number of unique targets, providing further evidence for SFB host selection. Together, this work represents a major advancement in identifying SFB and delineating how members of the group of SFB interact with the host. Future examination of FliC genes will likely enhance our knowledge of intestinal colonization by the gut microbiota.
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Epithelial-specific Toll-like Receptor (TLR)5 Activation Mediates Barrier Dysfunction in Experimental Ileitis. Inflamm Bowel Dis 2017; 23:392-403. [PMID: 28146004 DOI: 10.1097/mib.0000000000001035] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND A large body of evidence supports a central role of TLR5 and its natural ligand, flagellin, in Crohn's disease (CD), with the precise mechanism(s) still unresolved. METHODS We investigated the role of flagellin/TLR5 in SAMP1/YitFc (SAMP) mice, a spontaneous model of Crohn's disease-like ileitis. RESULTS Ileal Tlr5 and serum antiflagellin IgG antibodies were increased in SAMP before the onset of inflammation and during established disease; these trends were abrogated in the absence of colonizing commensal bacteria. Irradiated SAMP receiving either wild-type (AKR) or SAMP bone marrow (BM) developed severe ileitis and displayed increased ileal Tlr5 compared with AKR recipients of either SAMP or AKR bone marrow, neither of which conferred ileitis, suggesting that elevated TLR5 in native SAMP is derived primarily from a nonhematopoietic (e.g., epithelial) source. Indeed, ileal epithelial TLR5 in preinflamed SAMP was increased compared with age-matched AKR and germ-free SAMP. TLR5-specific ex vivo activation of SAMP ileal tissues decreased epithelial barrier resistance, indicative of increased permeability, and was accompanied by altered expression of the tight junction proteins, claudin-3, occludin, and zonula occludens-1. CONCLUSIONS Our results provide evidence that aberrant, elevated TLR5 expression is present in the ileal epithelium of SAMP mice, is augmented in the presence of the gut microbiome, and that TLR5 activation in response to bacterial flagellin results in a deficiency to maintain appropriate epithelial barrier integrity. Together, these findings represent a potential mechanistic pathway leading to the exacerbation and perpetuation of chronic gut inflammation in experimental ileitis and possibly, in patients with Crohn's disease.
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Carabarin-Lima A, León-Izurieta L, Rocha-Gracia RDC, Castañeda-Lucio M, Torres C, Gutiérrez-Cazarez Z, González-Posos S, Martínez de la Peña CF, Martinez-Laguna Y, Lozano-Zarain P. First evidence of polar flagella in Klebsiella pneumoniae isolated from a patient with neonatal sepsis. J Med Microbiol 2016; 65:729-737. [PMID: 27283194 DOI: 10.1099/jmm.0.000291] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The genus Klebsiella belongs to the family Enterobacteriaceae, and is currently considered to be non-motile and non-flagellated. In the present work, 25 Klebsiella strains isolated from nosocomial infections were assessed for motility under different growth conditions. One Klebsiella isolate, KpBUAP021, demonstrated a swim-like motility phenotype. The K. pneumoniae genotype was confirmed by 16S rRNA and rpoB gene sequence analysis. Multilocus sequence typing analysis also revealed that the KpBUAP021 strain places it in the ST345 sequence type, and belongs to the phylogenetic Kpl group. Transmission electron microscopy and the Ryu staining technique revealed that KpBUAP021 expresses polar flagella. Finally, the presence of fliC, fliA and flgH genes in this K. pneumoniae strain was confirmed. This report presents the first evidence for flagella-mediated motility in a K. pneumoniae clinical isolate, and represents an important finding related to its evolution and pathogenic potential.
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Affiliation(s)
- Alejandro Carabarin-Lima
- Benemérita Universidad Autónoma de Puebla, Instituto de Ciencias, Posgrado en Microbiología, Centro de Investigaciones en Ciencias Microbiológicas, Puebla, Mexico
| | - Libia León-Izurieta
- Benemérita Universidad Autónoma de Puebla, Instituto de Ciencias, Posgrado en Microbiología, Centro de Investigaciones en Ciencias Microbiológicas, Puebla, Mexico
| | - Rosa Del Carmen Rocha-Gracia
- Benemérita Universidad Autónoma de Puebla, Instituto de Ciencias, Posgrado en Microbiología, Centro de Investigaciones en Ciencias Microbiológicas, Puebla, Mexico
| | - Miguel Castañeda-Lucio
- Benemérita Universidad Autónoma de Puebla, Instituto de Ciencias, Posgrado en Microbiología, Centro de Investigaciones en Ciencias Microbiológicas, Puebla, Mexico
| | - Carmen Torres
- Área Bioquímica y Biología Molecular, Universidad de la Rioja, Logroño, Spain
| | - Zita Gutiérrez-Cazarez
- Laboratorio Clínico. Área de Microbiología. Hospital para el Niño Poblano. Blvd. del Niño Poblano No. 5307, Col. Concepción la Cruz, 72197 San Andrés, Cholula, Puebla, Mexico
| | | | - Claudia F Martínez de la Peña
- Benemérita Universidad Autónoma de Puebla, Instituto de Ciencias, Posgrado en Microbiología, Centro de Investigaciones en Ciencias Microbiológicas, Puebla, Mexico
| | - Ygnacio Martinez-Laguna
- Benemérita Universidad Autónoma de Puebla, Instituto de Ciencias, Posgrado en Microbiología, Centro de Investigaciones en Ciencias Microbiológicas, Puebla, Mexico
| | - Patricia Lozano-Zarain
- Benemérita Universidad Autónoma de Puebla, Instituto de Ciencias, Posgrado en Microbiología, Centro de Investigaciones en Ciencias Microbiológicas, Puebla, Mexico
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Ngamdee W, Tandhavanant S, Wikraiphat C, Reamtong O, Wuthiekanun V, Salje J, Low DA, Peacock SJ, Chantratita N. Competition between Burkholderia pseudomallei and B. thailandensis. BMC Microbiol 2015; 15:56. [PMID: 25879538 PMCID: PMC4365494 DOI: 10.1186/s12866-015-0395-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 02/19/2015] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Burkholderia pseudomallei is a Gram-negative bacterium that causes melioidosis, an often fatal disease in tropical countries. Burkholderia thailandensis is a non-virulent but closely related species. Both species are soil saprophytes but are almost never isolated together. RESULTS We identified two mechanisms by which B. pseudomallei affects the growth of B. thailandensis. First, we found that six different isolates of B. pseudomallei inhibited the growth of B. thailandensis on LB agar plates. Second, our results indicated that 55% of isolated strains of B. pseudomallei produced a secreted compound that inhibited the motility but not the viability of B. thailandensis. Analysis showed that the active compound was a pH-sensitive and heat-labile compound, likely a protein, which may affect flagella processing or facilitate their degradation. Analysis of bacterial sequence types (STs) demonstrated an association between this and motility inhibition. The active compound was produced from B. pseudomallei during the stationary growth phase. CONCLUSION Taken together, our results indicate that B. pseudomallei inhibits both the growth and motility of its close relative B. thailandensis. The latter phenomenon appears to occur via a previously unreported mechanism involving flagellar processing or degradation.
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Affiliation(s)
- Wikanda Ngamdee
- Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok, 10400, Thailand.
| | - Sarunporn Tandhavanant
- Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok, 10400, Thailand.
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
| | - Chanthiwa Wikraiphat
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
| | - Onrapak Reamtong
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
| | - Vanaporn Wuthiekanun
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
| | - Jeanne Salje
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
| | - David A Low
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA, USA.
- Biomolecular Science and Engineering Program, University of California, Santa Barbara, CA, USA.
| | - Sharon J Peacock
- Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok, 10400, Thailand.
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
- Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK.
| | - Narisara Chantratita
- Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok, 10400, Thailand.
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
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Flagellin typing of Bordetella bronchiseptica strains originating from different host species. Vet Microbiol 2014; 173:270-8. [PMID: 25153650 DOI: 10.1016/j.vetmic.2014.07.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2014] [Revised: 07/17/2014] [Accepted: 07/21/2014] [Indexed: 11/20/2022]
Abstract
Bordetella bronchiseptica is a widespread Gram-negative pathogen occurring in different mammal species. It is known to play a role in the aetiology of infectious atrophic rhinitis of swine, canine kennel cough, respiratory syndromes of cats, rabbits and guinea pigs, and sporadic human cases have also been reported. In this study, 93 B. bronchiseptica strains were examined from a broad range of host species and different geographical regions using restriction fragment length polymorphism analysis of polymerase chain reaction products of flaA to reveal the possible host-specificity of the flagellin. Eight types (A-H) of flaA were identified, including five newly described ones (D-H). All but one of the 22 B. bronchiseptica strains from swine showed type B fragment pattern. The eighteen Hungarian isolates of canine origin were uniform (type A) while in other countries type B and D were also present in dogs. The sequence and phylogenetic analysis of 36 representative strains of flaA types revealed four clusters. These clusters correlated with flaA PCR-RFLP types and host species, especially in pigs and dogs. The revealed diversity of the strains isolated from human cases indicated possible zoonotic transmissions from various animal sources.
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Truta B, Li DX, Mahadevan U, Fisher ER, Chen YY, Grace K, Velayos F, Terdiman JP. Serologic markers associated with development of Crohn's disease after ileal pouch anal anastomosis for ulcerative colitis. Dig Dis Sci 2014; 59:135-45. [PMID: 24091907 DOI: 10.1007/s10620-013-2866-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Accepted: 08/23/2013] [Indexed: 01/14/2023]
Abstract
BACKGROUND AND AIMS One of the causes of pouch failure after ileal pouch anal anastomosis (IPAA) for ulcerative colitis (UC) is the development of de novo Crohn's disease (CD). Our aim was to clearly define factors associated with post-IPAA CD. METHODS We conducted a cross-sectional study to compare demographic, clinical, and serological characteristics of patients with and without post-IPAA CD. All subjects underwent testing for anti-neutrophil cytoplasm antibodies, anti-Saccaromyces cerevisiae antibodies, anti-outer membrane porin C antibodies, and anti-CBir1 flagellin (anti-CBir1). A multivariable model assessed factors associated with post-IPAA CD. RESULTS Thirty-nine subjects were enrolled in the study: 20 cases and 19 controls. Patients who developed post-IPAA CD were significantly younger (median 22 ± 9.9 vs. 30 ± 11.3, p = .027) at the time of UC diagnosis and exhibited more extraintestinal manifestations compared to controls (p = .023). No significant difference between the groups was found with respect to family history, smoking, duration of illness prior to colectomy, time to the onset of pouchitis, preoperative treatment, and indication for surgery. However, the post-operative serologic profile differed significantly with far more cases having elevated anti-CBir1 titers (p = .016, OR 8.81), the latter being the only independent predictor in the combined model. CONCLUSIONS Patients with Crohn's disease of the pouch were more likely to have elevated CBir1 antibodies titers than those with simple pouchitis and healthy pouches. The stability of the CBir1 antibodies (pre- and post-colectomy) must be further assessed to establish its value as an independent predictor for development of post-IPAA CD.
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Tarahomjoo S. Utilizing bacterial flagellins against infectious diseases and cancers. Antonie van Leeuwenhoek 2013; 105:275-88. [PMID: 24276957 DOI: 10.1007/s10482-013-0075-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Accepted: 11/12/2013] [Indexed: 12/31/2022]
Abstract
The flagellum is the organelle providing motility to bacterial cells and its activity is coupled to the cellular chemotaxis machinery. The flagellar filament is the largest portion of the flagellum, which consists of repeating subunits of the protein flagellin. Receptors of the innate immune system including Toll like receptor 5, ICE protease activating factor, and neuronal apoptosis inhibitory protein 5 signal in response to bacterial flagellins. In addition to inducing innate immune responses, bacterial flagellins mediate the development of adaptive immune responses to both flagellins and coadministered antigens. Therefore, these proteins have intensively been investigated for the vaccine development and the immunotherapy. This review describes the utilization of bacterial flagellins for the construction of vaccines against infectious diseases and cancer immunotherapy. Furthermore, the key factors affecting the performance of these systems are highlighted.
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Affiliation(s)
- Shirin Tarahomjoo
- Department of Biotechnology, Razi Vaccine and Serum Research Institute, 31975/148, Karaj, Iran,
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Zhao X, Zhou ZJ, Han Y, Wang ZZ, Fan J, Xiao HZ. Isolation and identification of antifungal peptides from Bacillus BH072, a novel bacterium isolated from honey. Microbiol Res 2013; 168:598-606. [PMID: 23545354 DOI: 10.1016/j.micres.2013.03.001] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2013] [Revised: 02/27/2013] [Accepted: 03/02/2013] [Indexed: 10/27/2022]
Abstract
A bacterial strain BH072 isolated from a honey sample showed antifungal activity against mold. Based on morphological, biochemical, physiological tests, and analysis of 16S rDNA sequence, the strain was identified to be a new subspecies of Bacillus sp. It had a broad spectrum of antifungal activity against various mold, such as Aspergillus niger, Pythium, and Botrytis cinerea. Six pairs of antifungal genes primers were designed and synthesized, and ituA, hag, tasA genes were detected by PCR analysis. The remarkable antifungal activity could be associated with the co-production of these three peptides. One of them was purified by 30-40% ammonium sulfate precipitation, Sephadex G-75 gel filtration and anion exchange chromatography on D201 resin. The purified peptide was estimated to be 35.615 kDa and identified to be flagellin by micrOTOF-Q II. By using methanol extraction, another substance was isolated from fermentation liquor, and determined to be iturin with liquid chromatography-mass spectrometry (LC-MS) method. The third possible peptide encoded by tasA was not isolated in this study. The culture liquor displayed antifungal activity in a wide pH range (5.0-9.0) and at 40-100°C. The result of the present work suggested that Bacillus BH072 might be a bio-control bacterium of research value.
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Affiliation(s)
- Xin Zhao
- School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China
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Jia PP, Hu YH, Chi H, Sun BG, Yu WG, Sun L. Comparative study of four flagellins of Vibrio anguillarum: vaccine potential and adjuvanticity. FISH & SHELLFISH IMMUNOLOGY 2013; 34:514-520. [PMID: 23253494 DOI: 10.1016/j.fsi.2012.11.039] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Revised: 11/26/2012] [Accepted: 11/27/2012] [Indexed: 06/01/2023]
Abstract
Vibrio anguillarum is the etiological agent of vibriosis, an aquaculture disease that affects a wide range of farmed fish. The genome of V. anguillarum contains five flagellin genes, i.e. flaA, flaB, flaC, flaD, and flaE. In this study, we analyzed the vaccine potential and adjuvanticity of FlaA, FlaB, FlaD, and FlaE in a model of Japanese flounder (Paralichthys olivaceus). For this purpose, recombinant FlaA, FlaB, FlaD, and FlaE were expressed in and purified from Escherichia coli. In vivo immunogenicity analysis showed that antibodies against rFlaA, rFlaB, rFlaD, and rFlaE were detected in rat antiserum raised against live V. anguillarum, with the highest antibody level being that against rFlaB. When administered into flounder via intraperitoneal injection, rFlaA, rFlaD, and rFlaE induced comparable relative percent survival (RPS) rates, which were significantly lower than that induced by rFlaB. Specific serum antibodies were induced by all flagellins, however, the antibody level induced by rFlaB was significantly higher than those induced by other three flagellins. Compared to sera from fish vaccinated with rFlaA, rFlaD, and rFlaE, serum from fish vaccinated with rFlaB significantly reduced the infectivity of V. anguillarum against host cells. To examine the potential adjuvant effect of the flagellins, flounder were immunized with rEsa1, a D15-like surface antigen that induces protective immunity as a subunit vaccine, in the presence or absence of rFlaA, rFlaB, rFlaD, and rFlaE respectively. The results showed that rFlaE, but not other three flagellins, significantly increased the RPS of rEsa1. Compared to fish vaccinated with rEsa1, fish vaccinated with rEsa1 plus rFlaE exhibited a significantly higher level of serum antibodies and enhanced expression of the genes involved in innate and adaptive immunity. Taken together, these results indicate that FlaA, FlaB, FlaD, and FlaE have different immunological properties and, as a result, differ in vaccine and adjuvant potentials.
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Affiliation(s)
- Pan-pan Jia
- School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
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Van Vaerenbergh J, Baeyen S, De Vos P, Maes M. Sequence diversity in the Dickeya fliC gene: phylogeny of the Dickeya genus and TaqMan® PCR for 'D. solani', new biovar 3 variant on potato in Europe. PLoS One 2012; 7:e35738. [PMID: 22570692 PMCID: PMC3343043 DOI: 10.1371/journal.pone.0035738] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Accepted: 03/20/2012] [Indexed: 11/23/2022] Open
Abstract
Worldwide, Dickeya (formerly Erwinia chrysanthemi) is causing soft rot diseases on a large diversity of crops and ornamental plants. Strains affecting potato are mainly found in D. dadantii, D. dianthicola and D. zeae, which appear to have a marked geographical distribution. Furthermore, a few Dickeya isolates from potato are attributed to D. chrysanthemi and D. dieffenbachiae. In Europe, isolates of Erwinia chrysanthemi biovar 1 and biovar 7 from potato are now classified in D. dianthicola. However, in the past few years, a new Dickeya biovar 3 variant, tentatively named 'Dickeya solani', has emerged as a common major threat, in particular in seed potatoes. Sequences of a fliC gene fragment were used to generate a phylogeny of Dickeya reference strains from culture collections and with this reference backbone, to classify pectinolytic isolates, i.e. Dickeya spp. from potato and ornamental plants. The reference strains of the currently recognized Dickeya species and 'D. solani' were unambiguously delineated in the fliC phylogram. D. dadantii, D. dianthicola and 'D. solani' displayed unbranched clades, while D. chrysanthemi, D. zeae and D. dieffenbachiae branched into subclades and lineages. Moreover, Dickeya isolates from diagnostic samples, in particular biovar 3 isolates from greenhouse ornamentals, formed several new lineages. Most of these isolates were positioned between the clade of 'D. solani' and D. dadantii as transition variants. New lineages also appeared in D. dieffenbachiae and in D. zeae. The strains and isolates of D. dianthicola and 'D. solani' were differentiated by a fliC sequence useful for barcode identification. A fliC TaqMan®real-time PCR was developed for 'D. solani' and the assay was provisionally evaluated in direct analysis of diagnostic potato samples. This molecular tool can support the efforts to control this particular phytopathogen in seed potato certification.
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Affiliation(s)
- Johan Van Vaerenbergh
- Unit Plant Sciences-Crop Protection, Institute for Agricultural and Fisheries Research-ILVO, Merelbeke, Belgium.
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Papaneophytou CP, Papi RM, Pantazaki AA, Kyriakidis DA. Flagellin gene (fliC) of Thermus thermophilus HB8: characterization of its product and involvement to flagella assembly and microbial motility. Appl Microbiol Biotechnol 2012; 94:1265-77. [DOI: 10.1007/s00253-012-3913-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Revised: 01/16/2012] [Accepted: 01/19/2012] [Indexed: 11/29/2022]
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Colak DN, Inan K, Karaoglu H, Canakci S, Belduz AO. Molecular analysis of the genus Anoxybacillus based on sequence similarity of the genes recN, flaA, and ftsY. Folia Microbiol (Praha) 2012; 57:61-9. [PMID: 22223049 DOI: 10.1007/s12223-011-0094-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Accepted: 12/13/2011] [Indexed: 11/24/2022]
Abstract
Genome predictions based on selected genes would be a very welcome approach for taxonomic studies. We analyzed three genes, recN, flaA, and ftsY, for determining if these genes are useful tools for systematic analyses in the genus Anoxybacillus. The genes encoding a DNA repair and genetic recombination protein (recN), the flagellin protein (flaA), and GTPase signal docking protein (ftsY) were sequenced for ten Anoxybacillus species. The sequence comparisons revealed that recN sequence similarities range between 61% and 99% in the genus Anoxybacillus. Comparisons to other bacterial recN genes indicated that levels of similarity did not differ from the levels within genus Anoxybacillus. These data showed that recN is not a useful marker for the genus Anoxybacillus. A 550-600-bp region of the flagellin gene was amplified for all Anoxybacillus strains except for Anoxybacillus contaminans. The sequence similarity of flaA gene varies between 61% and 76%. Comparisons to other bacterial flagellin genes obtained from GenBank (Bacillus, Pectinatus, Proteus, and Vibrio) indicated that the levels of similarity were lower (3-42%). Based on these data, we concluded that the variability in this single gene makes it a particularly useful marker. Another housekeeping gene ftsY suggested to reflect the G+C (mol/mol) content of whole genome was analyzed for Anoxybacillus strains. A mean difference of 1.4% was observed between the G+C content of the gene ftsY and the G+C content of the whole genome. These results showed that the gene ftsY can be used to represent whole G+C content of the Anoxybacillus species.
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Affiliation(s)
- Dilsat Nigar Colak
- Department of Biology, Faculty of Sciences, Karadeniz Technical University, Trabzon, Turkey
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Kajikawa A, Igimi S. Development of recombinant vaccines in lactobacilli for elimination of salmonella. Biosci Microflora 2011; 30:93-8. [PMID: 25045314 PMCID: PMC4103640 DOI: 10.12938/bifidus.30.93] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2011] [Indexed: 11/29/2022] Open
Abstract
Many Lactobacillus and Lactococcus strains are
generally regarded as safe for consumption because they are utilized for food fermentation
or inhabit the intestinal mucosa as commensals. Recently, vaccine delivery systems using
lactic acid bacteria (LAB) have been under development. Our research group has been
investigating the development of oral mucosal vaccines against Salmonella
enterica serovar Enteritidis (SE) using Lactobacillus casei
IGM393 as an antigen delivery vehicle. Recombinant lactobacilli expressing SE antigens,
FliC, SipC, and OmpC, have been constructed and orally administered to mice. Antigen
specific immune responses and protective immunity were elicited after the immunization.
For adjuvant-delivery, IL-1β-secreting L. casei was also engineered and
its effects evaluated in vitro and in vivo. This article
reviews a novel approach to the elimination of Salmonella via the
development of a vaccine in lactobacilli.
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Affiliation(s)
- Akinobu Kajikawa
- Department of Food, Bioprocessing, & Nutrition Sciences, North Carolina State University, 341 Schaub Hall, North Carolina State University, Raleigh, NC 27695, USA
| | - Shizunobu Igimi
- Division of Biomedical Food Research, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan
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Ayala CDO, Ramos Moreno AC, Martinez MB, Burgos YK, Pestana de Castro AF, Bando SY. Determination of flagellar types by PCR-RFLP analysis of enteropathogenic Escherichia coli (EPEC) and Shiga toxin-producing E. coli (STEC) strains isolated from animals in São Paulo, Brazil. Res Vet Sci 2010; 92:18-23. [PMID: 21094508 DOI: 10.1016/j.rvsc.2010.10.025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2010] [Revised: 10/14/2010] [Accepted: 10/25/2010] [Indexed: 10/18/2022]
Abstract
This study evaluated the polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP) analysis of fliC for typing flagella antigen (H) of Shiga toxin-producing Escherichia coli (STEC) and enteropathogenic E. coli (EPEC) strains isolated from different animals. The molecular typing of the H type was efficient in the determination of 93 (85%) strains. Two nonmotile (H-) E. coli strains showed a PCR-RFLP electrophoretic profile that did not match known H type patterns. The fliC nucleotide sequence of strains B2N and 4a revealed a nucleotide substitution at the restriction site and a nucleotide insertion that generated a stop codon, respectively. The results of this study showed that PCR-RFLP analysis of fliC is faster, less laborious and as efficient for the determination of H type E. coli isolated from animals, compared to serotyping and that it is useful in determining H type in nonmotile strains and strains expressing non-reactive H antigens. Moreover, the fliC sequence of strain B2N suggests that we could have found a new flagellin antigen type.
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Dissection and localization of the immunostimulating domain of Edwardsiella tarda FliC. Vaccine 2010; 28:5635-40. [DOI: 10.1016/j.vaccine.2010.06.022] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2010] [Revised: 05/29/2010] [Accepted: 06/04/2010] [Indexed: 11/23/2022]
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Madic J, Peytavin de Garam C, Vingadassalon N, Oswald E, Fach P, Jamet E, Auvray F. Simplex and multiplex real-time PCR assays for the detection of flagellar (H-antigen) fliC alleles and intimin (eae) variants associated with enterohaemorrhagic Escherichia coli (EHEC) serotypes O26:H11, O103:H2, O111:H8, O145:H28 and O157:H7. J Appl Microbiol 2010; 109:1696-705. [PMID: 20618885 DOI: 10.1111/j.1365-2672.2010.04798.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIMS To develop real-time PCR assays targeting genes encoding the flagellar antigens (fliC) and intimin subtypes (eae) associated with the five most clinically important serotypes of enterohaemorrhagic Escherichia coli (EHEC), i.e. O26:H11, O103:H2, O111:H8, O145:H28 and O157:H7. METHODS AND RESULTS Primers and probes specific to fliC(H2) , fliC(H7) , fliC(H8) , fliC(H11) , fliC(H28) , eae-β1, eae-γ1, eae-ε and eae-θ were combined in simplex and multiplex 5'-nuclease PCR assays. The specificity of the assays was assessed on 201 bacterial strains and the sensitivity determined on serially diluted EHEC genomes. The developed PCR assays were found to be highly specific and detected as few as five EHEC genome equivalents per reaction. Furthermore, it was possible to detect the five major EHEC serotypes in cheese samples inoculated at concentration levels of ≤5CFU per 25g after overnight enrichment using the PCR assays. CONCLUSIONS The PCR assays developed here were found to be sensitive and specific for the reliable detection of genes encoding the flagellar antigens and intimin variants belonging to the five most clinically relevant EHEC serotypes. SIGNIFICANCE AND IMPACT OF THE STUDY Application of real-time PCR assays should improve the identification of foods contaminated by EHEC and facilitate the molecular typing of these organisms.
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Affiliation(s)
- J Madic
- Agence Française de Sécurité Sanitaire des Aliments, Laboratoire d'Etudes et de Recherches sur la Qualité des Aliments et sur les Procédés agroalimentaires (AFSSA-LERQAP), Maisons-Alfort, France
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Badri S, Fassouane A, Filliol I, Hassar M, Cohen N. Sequence analysis of the gene encoding H antigen in Escherichia coli isolated from food in Morocco. J Microbiol 2010; 48:184-7. [PMID: 20437150 DOI: 10.1007/s12275-010-9182-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2009] [Accepted: 10/14/2009] [Indexed: 12/16/2022]
Abstract
In order to develop other molecular method useful for typing of motile and non motile Escherichia coli strains, a total of 207 strains of E. coli (133 reference strains, 74 food strains) were characterized by analysis of sequences of their amplified flagellin-encoding (fliC) gene products. The collection of reference strains was used for database building of fliC gene sequences. Application of this identification system to 74 E. coli food isolates revealed a reproducible and clear cut classification with very good correlation to results obtained by HhaI restriction of the amplified flagellin gene. The proposed determination of fliC sequences variations should be helpful for epidemiological studies.
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Affiliation(s)
- Samira Badri
- Laboratoire de Microbiologie et d'Hygiène des Aliments et de l'Environnement, Institut Pasteur du Maroc, Casablanca, 20100, Morocco.
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Ratiner YA, Sihvonen LM, Liu Y, Wang L, Siitonen A. Alteration of flagellar phenotype of Escherichia coli strain P12b, the standard type strain for flagellar antigen H17, possessing a new non-fliC flagellin gene flnA, and possible loss of original flagellar phenotype and genotype in the course of subculturing through semisolid media. Arch Microbiol 2010; 192:267-78. [PMID: 20174918 DOI: 10.1007/s00203-010-0556-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2009] [Accepted: 02/03/2010] [Indexed: 11/30/2022]
Abstract
A practically important phenomenon, resulting in the loss of the original flagellar phenotype (genotype) of bacteria, is described in the Escherichia coli H17 type strain P12b possessing two distinct genes for H17 and H4 flagellins, respectively. By PCR, sequencing, and phylogenetic investigation, the H17 gene (originally expressed) was considered a new non-fliC flagellin gene and assigned flnA, while the H4 gene (originally cryptic) was reaffirmed as fliC. H17 and H4 flagella differed morphologically. The phenomenon consisted in the replacement of H17 cells by H4 cells during subculturing through certain semisolid media and resulted from the excision of flnA (H17) entirely or in part. The substitution rate depended on the density and nutrient composition of media and reached 100% even after a single passage through 0.3% LB agar. Such phenomenon can lead to an unexpected loss of original H17 phenotype. Our review of the literature showed that the loss of the original flagellar genotype (phenotype) of P12b has occurred in some laboratories while the authors continued to consider their cultures H17. We showed how to distinguish these alternative flagellin genotypes using popular fliC primers. Attention was also paid to possible discrepancies between serological and molecular results in flagellar typing of E. coli.
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Affiliation(s)
- Yuliy A Ratiner
- Department of Microbiology, Mechnikov Research Institute for Vaccines and Sera of The Russian Academy of Medical Sciences, Moscow, Russia.
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IgA and IgG antibody responses following systemic immunization of cattle with native H7 flagellin differ in epitope recognition and capacity to neutralise TLR5 signalling. Vaccine 2010; 28:1412-21. [DOI: 10.1016/j.vaccine.2009.10.148] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2009] [Revised: 10/05/2009] [Accepted: 10/14/2009] [Indexed: 01/19/2023]
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Sequence polymorphism and PCR-restriction fragment length polymorphism analysis of the flagellin gene of Burkholderia pseudomallei. J Clin Microbiol 2010; 48:1465-7. [PMID: 20089759 DOI: 10.1128/jcm.01131-09] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Four flagellin allelic types (I to IV) of Burkholderia pseudomallei were identified based on their sequence variation and restriction fragment length polymorphism (RFLP) analysis of the amplified flagellin gene. Flagellin allelic type I was the most predominantly (75.0%) found among the 100 clinical isolates of B. pseudomallei investigated in this study.
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Hwang BH, Lee JW, Cha HJ. Polymerase chain reaction-based detection of total and specific Vibrio species. Appl Biochem Biotechnol 2009; 162:1187-94. [PMID: 19937156 DOI: 10.1007/s12010-009-8853-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2009] [Accepted: 11/03/2009] [Indexed: 11/29/2022]
Abstract
The polymerase chain reaction (PCR) technique is widely used for efficient detection of food-borne pathogens because of speed and specificity. However, PCR methods have focused mostly on species-specific detection. In the present work, we describe a PCR-based method for the simultaneous detection of all Vibrio species because lots of them are notorious food-borne human pathogens. We then combined this total detection method with specific detection of Vibrio cholerae pathogen. Using a degenerate primer set based on the sequence of the potassium uptake gene, trkA, we were able to successfully detect all Vibrio species. Specific detection of V. cholerae was also possible using primer sets based on putative flagellin sequence. Importantly, simultaneous total and species-specific Vibrio detection was possible using all two primer sets in a multiplexed PCR strategy. Thus, the PCR method we have developed is applicable to both simultaneous and two-step detection of total and specific Vibrio species.
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Affiliation(s)
- Byeong Hee Hwang
- National Research Laboratory of Molecular Biotechnology, Department of Chemical Engineering, Pohang University of Science and Technology, Pohang 790-784, South Korea
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Abstract
Species of the Cronobacter genus ("Enterobacter sakazakii" s. l.) are emergent food-borne pathogens that can cause rare but severe neonatal meningitis, bacteriaemia, and necrotizing enterocolitis. Preterm, low-birth-weight, and immuno-compromised infants exposed to these bacterial species are at particular risk. Over the last 50 years, the literature has reported, mainly in newborn children, more than one hundred cases of infection due to these pathogens. The objective of this review was to synthesize the recent advances in knowledge of species of the Cronobacter genus, in particular with regards to taxonomy, physiology, pathogenicity, clinical cases, the methods for detection, isolation, and characterization, and their presence in powdered formulae for infants and young children, which were identified as the main infection vector. Researchers and international public health authorities have explored the ways contamination occur to better control the risks of pathogen development. Appropriate analysis and control measures were implemented in areas processing powdered formulae for infants and young children, and caregivers and families were informed to undertake good hygienic practices.
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Affiliation(s)
- Isabelle Proudy
- Service de microbiologie, Equipe d'accueil 2128, Centre hospitalier universitaire, Université de Caen Basse-Normandie, avenue Côte de Nacre, Caen CEDEX, France.
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Farfán M, Miñana-Galbis D, Fusté MC, Lorén JG. Divergent evolution and purifying selection of the flaA gene sequences in Aeromonas. Biol Direct 2009; 4:23. [PMID: 19622168 PMCID: PMC2724415 DOI: 10.1186/1745-6150-4-23] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2009] [Accepted: 07/21/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The bacterial flagellum is the most important organelle of motility in bacteria and plays a key role in many bacterial lifestyles, including virulence. The flagellum also provides a paradigm of how hierarchical gene regulation, intricate protein-protein interactions and controlled protein secretion can result in the assembly of a complex multi-protein structure tightly orchestrated in time and space. As if to stress its importance, plants and animals produce receptors specifically dedicated to the recognition of flagella. Aside from motility, the flagellum also moonlights as an adhesion and has been adapted by humans as a tool for peptide display. Flagellar sequence variation constitutes a marker with widespread potential uses for studies of population genetics and phylogeny of bacterial species. RESULTS We sequenced the complete flagellin gene (flaA) in 18 different species and subspecies of Aeromonas. Sequences ranged in size from 870 (A. allosaccharophila) to 921 nucleotides (A. popoffii). The multiple alignment displayed 924 sites, 66 of which presented alignment gaps. The phylogenetic tree revealed the existence of two groups of species exhibiting different FlaA flagellins (FlaA1 and FlaA2). Maximum likelihood models of codon substitution were used to analyze flaA sequences. Likelihood ratio tests suggested a low variation in selective pressure among lineages, with an omega ratio of less than 1 indicating the presence of purifying selection in almost all cases. Only one site under potential diversifying selection was identified (isoleucine in position 179). However, 17 amino acid positions were inferred as sites that are likely to be under positive selection using the branch-site model. Ancestral reconstruction revealed that these 17 amino acids were among the amino acid changes detected in the ancestral sequence. CONCLUSION The models applied to our set of sequences allowed us to determine the possible evolutionary pathway followed by the flaA gene in Aeromonas, suggesting that this gene have probably been evolving independently in the two groups of Aeromonas species since the divergence of a distant common ancestor after one or several episodes of positive selection. REVIEWERS This article was reviewed by Alexey Kondrashov, John Logsdon and Olivier Tenaillon (nominated by Laurence D Hurst).
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Affiliation(s)
- Maribel Farfán
- Departament de Microbiologia i Parasitologia Sanitàries, Facultat de Farmàcia, Universitat de Barcelona, Av. Joan XXIII s/n, 08028 Barcelona, Spain.
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Shen C, Landers CJ, Derkowski C, Elson CO, Targan SR. Enhanced CBir1-specific innate and adaptive immune responses in Crohn's disease. Inflamm Bowel Dis 2008; 14:1641-51. [PMID: 18825772 PMCID: PMC3346963 DOI: 10.1002/ibd.20645] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
BACKGROUND CBir1 is a dominant antigen with a role in innate and adaptive immunity in mouse models of colitis and antibodies to CBir1 are associated with severe human Crohn's disease (CD). Our aim was to determine whether CBir1 stimulates innate and antigen-specific T-cell responses in CD. We demonstrate that CBir1 enhanced IL-6 and IL-1beta production by peripheral blood (PB) monocytes. METHODS Real time polymerase chain reaction (PCR) was used for measurement of IL6 and IL1 expression. [(3)H] thymidine was used to measure T cell proliferation and Elispot assay was used to measure IFNgamma production. RESULTS IL-6 was significantly increased in monocytes from CD compared to controls and ulcerative colitis (UC). Anti-CBir1(+) patients and IL-6 was inversely correlated. A significant increase in CBir1-specific peripheral T-cell proliferation was more evident in cells from CD than controls and UC. CBir1 induced increased numbers of IFN-gamma(+) cells in lamina propria mononuclear cells (LPMC) from CD compared to UC and controls. CONCLUSIONS CBir1 induces enhanced peripheral innate and peripheral and mucosal antigen-specific T-cell responses in CD. Consistent with results from the mouse, CBir1 immune activation could play a role in CD.
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Affiliation(s)
- Chong Shen
- Inflammatory Bowel Disease Research Center, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Carol J. Landers
- Inflammatory Bowel Disease Research Center, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Carrie Derkowski
- Inflammatory Bowel Disease Research Center, Cedars-Sinai Medical Center, Los Angeles, CA
| | | | - Stephan R. Targan
- Inflammatory Bowel Disease Research Center, Cedars-Sinai Medical Center, Los Angeles, CA
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Ho HTK, Lipman LJA, Wösten MMSM, van Asten AJAM, Gaastra W. Arcobacter spp. possess two very short flagellins of which FlaA is essential for motility. ACTA ACUST UNITED AC 2008; 53:85-95. [PMID: 18400014 DOI: 10.1111/j.1574-695x.2008.00405.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Like Campylobacter and Helicobacter spp., Arcobacter spp. possess two flagellin genes (flaA and flaB) located adjacent to each other. The aim of this study was to characterize the flagellin proteins of Arcobacter spp., because these proteins are known virulence factors in the Epsilonproteobacteria, to which these three species belong. With the exception of Arcobacter nitrofigilis, Arcobacter flagellins are almost half the size of those in other Epsilonproteobacteria. Arcobacter flagellin proteins lack a large part of the variable central region. The low homology observed among flagellins of different Arcobacter species indicates genetic heterology between the members of this genus. Unlike in other Epsilonproteobacteria, the transcription of flagellin genes is not regulated by sigma 28- or sigma 54-dependent promoters, which suggests that transcription must be regulated in a different way in Arcobacter spp. Mutational studies revealed that only FlaA is needed for the motility of Arcobacter spp. Quantitative PCR analysis showed that transcription of flaB is higher at 30 degrees C than at 37 degrees C. Mutation of flaB had no effect on motility or on flaA transcription while mutation of flaA abolished motility and increased the transcription of flaB. These results underline that the genus Arcobacter is an unusual taxon in the epsilon subdivision of the Proteobacteria.
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Affiliation(s)
- Hoa T K Ho
- Faculty of Veterinary Medicine, Utrecht University, The Netherlands
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Auvray F, Lecureuil C, Taché J, Perelle S, Fach P. Development of a 5'-nuclease PCR assay for the identification of Escherichia coli strains expressing the flagellar antigen H21 and their detection in food after enrichment. J Appl Microbiol 2008; 104:899-905. [DOI: 10.1111/j.1365-2672.2007.03607.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Proudy I, Bouglé D, Coton E, Coton M, Leclercq R, Vergnaud M. Genotypic characterization of Enterobacter sakazakii isolates by PFGE, BOX-PCR and sequencing of the fliC gene. J Appl Microbiol 2007; 104:26-34. [PMID: 17850301 DOI: 10.1111/j.1365-2672.2007.03526.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
AIMS Enterobacter sakazakii is an emerging food-borne pathogen that can cause rare but severe forms of neonatal meningitis, bacteraemia and necrotizing enterocolitis. A rapid typing method at the strain level is needed to determine the monoclonality or polyclonality of the isolates during outbreaks. METHODS AND RESULTS The BOX-PCR fingerprinting technique, which targets the repetitive BOX sequences, and sequencing of the flagellin gene, fliC, were evaluated against a panel of 27 Ent. sakazakii strains from clinical and environmental sources. The typeability and discriminatory power of the techniques were compared with those of pulsed-field gel electrophoresis (PFGE), the reference genotyping method. BOX-PCR results yielded 92% agreement with PFGE results, whereas fliC gene sequencing was poorly discriminative. CONCLUSIONS In our study, BOX-PCR and PFGE were similarly discriminatory to type Ent. sakazakii strains. The weak variability of the Ent. sakazakii fliC gene was related to the absence of the variable central domain present in most fliC genes of Enterobacteriaceae. SIGNIFICANCE AND IMPACT OF THE STUDY The BOX-PCR typing provides an accurate discrimination and a rapid answer to identify clonal isolates of Ent. sakazakii.
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Affiliation(s)
- I Proudy
- Service de Microbiologie, EA 2128 Interactions Hôte et Microorganismes des Epithéliums, CHU Côte de Nacre, Université de Caen Basse-Normandie, Caen Cedex, France
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Paul CJ, Tran S, Tam KJ, Austin JW. A unique restriction site in the flaA gene allows rapid differentiation of group I and group II Clostridium botulinum strains by PCR-restriction fragment length polymorphism analysis. J Food Prot 2007; 70:2133-9. [PMID: 17900093 DOI: 10.4315/0362-028x-70.9.2133] [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: 11/11/2022]
Abstract
Clostridium botulinum produces the potent botulinum neurotoxin, the causative agent of botulism. Based on distinctive physiological traits, strains of C. botulinum can be divided into four groups: however, only groups I and II are associated with human illness. Alignment of the flaA gene sequences from 40 group I and 40 group II strains identified a single BsrG1 restriction cut site that was present at base pair 283 in all group II flaA sequences and was not found in any group I sequence. The flaA gene was amplified by rapid colony PCR from 22 group I strains and 18 group II strains and digested with BsrGI restriction enzyme. Standard agarose gel electrophoresis with ethidium bromide staining showed two fragments, following restriction digestion of group II flaA gene amplicons with BsrGI, but only a single band of uncut flaA from group I strains. Combining rapid colony PCR with BsrGI restriction digest of the flaA gene at 60 degrees C is a significant improvement over current methods, such as meat digestion or amplified fragment length polymorphism, as a strain can be identified as either group I or group II in under 5 h when starting with a visible plated C. botulinum colony.
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Affiliation(s)
- Catherine J Paul
- Bureau of Microbial Hazards, Health Products and Food Branch, Health Canada, Sir Frederick G. Banting Research Centre, 251 Sir Frederick Banting Driveway, Ottawa, Ontario, Canada K0A 0K9
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Tominaga A, Kutsukake K. Expressed and cryptic flagellin genes in the H44 and H55 type strains of Escherichia coli. Genes Genet Syst 2007; 82:1-8. [PMID: 17396015 DOI: 10.1266/ggs.82.1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Bacterial H antigens are specified by flagellin molecules, which constitute the flagellar filament. Escherichia coli 781-55 and E2987-73 are the type strains for H44 and H55 antigens, respectively. Unlike E. coli K-12, they possess two flagellin genes, fliC and fllA, on their chromosomes. However, they are monophasic, expressing exclusively the fllA genes, which specify the type antigens. In this study, the flagellin genes were cloned from these strains and their structure and expression were analyzed. It was found that the fliC genes encode apparently intact flagellin subunits but possess inefficient sigma28-dependent promoters, which may result in these genes being silent. The chromosomal locations of the fllA genes are approximately, but not exactly, identical with that of the phase-2 flagellin gene, fljB, of diphasic Salmonella strains. However, unlike the Salmonella fljB gene, the invertible H segment and the fljA gene responsible for the control of flagellar phase variation are both absent from the fllA loci. The fllA genes are highly homologous to the E. coli fliC gene but distantly related to the Salmonella fljB gene. These results suggest a hypothesis that the fllA genes may have emerged by an intra-species lateral transfer of the fliC gene. This hypothesis is further supported by the observation that the fllA genes are flanked by several IS elements and located within cryptic prophage elements.
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Affiliation(s)
- Akira Tominaga
- Graduate School of Natural Science and Technology and Department of Biology, Faculty of Science, Okayama University, Japan
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Demirkan I, Williams HF, Dhawi A, Carter SD, Winstanley C, Bruce KD, Hart CA. Characterization of a spirochaete isolated from a case of bovine digital dermatitis. J Appl Microbiol 2007; 101:948-55. [PMID: 16968306 DOI: 10.1111/j.1365-2672.2006.02976.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIMS The aim of the study was to characterize a spirochaete isolated from the lesions of a cow with digital dermatitis (DD). METHODS AND RESULTS The characterization was on the basis of its light and electron microscopic appearance, enzymic profile and DNA sequence analysis of its flagellin and 16S rRNA genes. The spirochaete was 6-8-microm long and 0.2-0.3 microm in diameter, and possessed seven to eight periplasmic flagella, with three to five helical turns. The enzymic profile of the bacterium resembles, but is not identical to that of Treponema brennaborense. Its flagellin gene sequence was identical to that of Treponema phagedenis but distinct from that of an ovine spirochaete. Analysis of a 1477-bp region of the 16S rRNA genes indicated that this is a Treponema species and that it is indistinguishable from some isolates made from cases of bovine DD in the United States. Finally, electron microscopy revealed the presence of myovirus-like bacteriophage particles in all cultures of the treponeme examined. CONCLUSIONS The spirochaete isolate was identified as a Treponema species closely related to some isolates from the United States (by 16S rDNA) and to T. phagedenis (by flagellin gene sequence) and is associated with bacteriophage particles. SIGNIFICANCE AND IMPACT OF THE STUDY The fact that the isolates with the same or very similar 16S rDNA sequences have been obtained from cases of bovine DD in cattle in different countries at different times, lends further support to the hypothesis that treponemes play a role in the pathogenesis of this disease.
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Affiliation(s)
- I Demirkan
- Department of Medical Microbiology, University of Liverpool, Liverpool, UK
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Ruelle V, Falisse-Poirrier N, Elmoualij B, Zorzi D, Pierard O, Heinen E, De Pauw E, Zorzi W. An immuno-PF2D-MS/MS proteomic approach for bacterial antigenic characterization: to Bacillus and beyond. J Proteome Res 2007; 6:2168-75. [PMID: 17488104 DOI: 10.1021/pr060661g] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We are confronted daily to unknown microorganisms that have yet to be characterized, detected, and/or analyzed. We propose, in this study, a multidimensional strategy using polyclonal antibodies, consisting of a novel proteomic tool, the ProteomeLab PF2D, coupled to immunological techniques and mass spectrometry (i-PF2D-MS/MS). To evaluate this strategy, we have applied it to Bacillus subtilis, considered here as our unknown bacterial model.
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Affiliation(s)
- Virginie Ruelle
- Center of Research on Prion Proteins, University of Liège, B-4000 Liège, Belgium
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44
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Baldy-Chudzik K, Stosik M. Diversity offliC gene in commensalEscherichia coli derived from various mammals. Folia Microbiol (Praha) 2007; 52:261-72. [PMID: 17702465 DOI: 10.1007/bf02931308] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Relations between the diversity of the fliC gene conditioning flagellum protein in E. coli and the source of the strain origin are presented. The fliC genes have been identified and characterized in commensal E. coli derived from 10 healthy animal species living in Zoo Safari Park (Poland). The fliC gene was found in 150 strains by the PCR method. The amplifiedfliC products revealed single bands within the range 1.26-2.16 kbp. Forty restriction patterns (classed by restriction analysis with the use of RsaI (PCR-RFLP RsaI; R-types) were determined. The neighbor-joining method was employed to illustrate the distribution of the kinds of R-types. There are 3-8 various R-types of a diversified frequency of occurrence in strains. Application of PCR-RFLP RsaI permitted the identification of alleles of fliC genes characteristic for E. coli and the estimation of their diversity among the animal species. The transmission ways of E. coli fliC+ between organisms of different species were determined and confirmed the role of transmission and horizontal gene transfer in the generation of the allelic diversity of fliC gene in natural E. coli populations.
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Affiliation(s)
- K Baldy-Chudzik
- Department of Microbiology and Genetics, Institute of Biotechnology and Environmental Science, University of Zielona Góra, 65-561 Zielona Góra, Poland.
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López-Enríquez L, Rodríguez-Lázaro D, Hernández M. Quantitative detection of Clostridium tyrobutyricum in milk by real-time PCR. Appl Environ Microbiol 2007; 73:3747-51. [PMID: 17449705 PMCID: PMC1932699 DOI: 10.1128/aem.02642-06] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We developed a real-time PCR assay for the quantitative detection of Clostridium tyrobutyricum, which has been identified as the major causal agent of late blowing in cheese. The assay was 100% specific, with an analytical sensitivity of 1 genome equivalent in 40% of the reactions. The quantification was linear (R(2) > 0.9995) over a 5-log dynamic range, down to 10 genome equivalents, with a PCR efficiency of >0.946. With optimized detergent treatment and enzymatic pretreatment of the sample before centrifugation and nucleic acid extraction, the assay counted down to 300 C. tyrobutyricum spores, with a relative accuracy of 82.98 to 107.68, and detected as few as 25 spores in 25 ml of artificially contaminated raw or ultrahigh-temperature-treated whole milk.
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Affiliation(s)
- Lorena López-Enríquez
- Instituto Tecnológico Agrario de Castilla y León, Carretera de Burgos, km. 119, 47071 Valladolid, Spain
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Paul CJ, Twine SM, Tam KJ, Mullen JA, Kelly JF, Austin JW, Logan SM. Flagellin diversity in Clostridium botulinum groups I and II: a new strategy for strain identification. Appl Environ Microbiol 2007; 73:2963-75. [PMID: 17351097 PMCID: PMC1892883 DOI: 10.1128/aem.02623-06] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Strains of Clostridium botulinum are traditionally identified by botulinum neurotoxin type; however, identification of an additional target for typing would improve differentiation. Isolation of flagellar filaments and analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that C. botulinum produced multiple flagellin proteins. Nano-liquid chromatography-tandem mass spectrometry (nLC-MS/MS) analysis of in-gel tryptic digests identified peptides in all flagellin bands that matched two homologous tandem flagellin genes identified in the C. botulinum Hall A genome. Designated flaA1 and flaA2, these open reading frames encode the major structural flagellins of C. botulinum. Colony PCR and sequencing of flaA1/A2 variable regions classified 80 environmental and clinical strains into group I or group II and clustered isolates into 12 flagellar types. Flagellar type was distinct from neurotoxin type, and epidemiologically related isolates clustered together. Sequencing a larger PCR product, obtained during amplification of flaA1/A2 from type E strain Bennett identified a second flagellin gene, flaB. LC-MS analysis confirmed that flaB encoded a large type E-specific flagellin protein, and the predicted molecular mass for FlaB matched that observed by SDS-PAGE. In contrast, the molecular mass of FlaA was 2 to 12 kDa larger than the mass predicted by the flaA1/A2 sequence of a given strain, suggesting that FlaA is posttranslationally modified. While identification of FlaB, and the observation by SDS-PAGE of different masses of the FlaA proteins, showed the flagellin proteins of C. botulinum to be diverse, the presence of the flaA1/A2 gene in all strains examined facilitates single locus sequence typing of C. botulinum using the flagellin variable region.
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Affiliation(s)
- Catherine J Paul
- Bureau of Microbial Hazards, HFPB, Health Canada, Sir Frederick G. Banting Research Centre, Ottawa, Ontario, Canada
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Chung JW, Speert DP. Proteomic identification and characterization of bacterial factors associated with Burkholderia cenocepacia survival in a murine host. Microbiology (Reading) 2007; 153:206-14. [PMID: 17185549 DOI: 10.1099/mic.0.2006/000455-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Burkholderia cenocepacia is a member of the Burkholderia cepacia complex, a diverse family of Gram-negative bacteria that are serious respiratory pathogens in immunocompromised patients and individuals with cystic fibrosis. To identify putative bacterial virulence determinants, proteomic profiles were compared between two B. cenocepacia isolates that demonstrated differential persistence in a mouse model of pulmonary infection; clinical isolate C1394 is rapidly cleared from the murine lung whereas the strain variant, C1394mp2, persists. Two-dimensional (2D) gel electrophoresis was used to identify candidate proteins involved in B. cenocepacia survival in a susceptible host. The 2D proteome of the persistent isolate (C1394mp2) revealed loss of an alkyl hydroperoxide reductase subunit C (AhpC) protein spot and increased production of flagellin proteins. Loss of AhpC expression in C1394mp2 correlated with enhanced susceptibility to oxidative stress. C1394mp2 expressed increased flagellin production and enhanced swimming motility, traits that were subject to regulation by heat and low pH. Together, these results revealed differential expression and stress regulation of putative virulence determinants associated with B. cenocepacia persistence in a susceptible host.
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Affiliation(s)
- Jacqueline W Chung
- Department of Paediatrics, University of British Columbia, Child and Family Research Institute, Vancouver, British Columbia, Canada
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Okugawa S, Yanagimoto S, Tsukada K, Kitazawa T, Koike K, Kimura S, Nagase H, Hirai K, Ota Y. Bacterial flagellin inhibits T cell receptor-mediated activation of T cells by inducing suppressor of cytokine signalling-1 (SOCS-1). Cell Microbiol 2006; 8:1571-80. [PMID: 16984412 DOI: 10.1111/j.1462-5822.2006.00731.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Flagellin, the structural component of bacterial flagella, is secreted by pathogenic and commensal bacteria, and is recognized by Toll-like receptor (TLR) 5. Flagellin is a common bacterial antigen present on most motile bacteria and is speculated to contribute to the activation of CD4+ T cells in the intestine. However, molecular mechanisms by which flagellin regulate T cell activation remains to be determined. Using Jurkat T cells or human primary T cell, we showed that flagellin stimulation induced tyrosine phosphorylation of TLR5 and activation of both mitogen-activated protein kinases and nuclear factor kappaB. In addition, stimulation by flagellin did not induce nuclear factor of activated T cells (NFAT) activation, while stimulation via the T cell receptor (TCR) leads to activation of NFAT. However, TCR-mediated NFAT activation and tyrosine phosphorylation of zeta-associated protein 70 (Zap-70) were inhibited in cells pre-stimulated by flagellin. Furthermore, flagellin stimulation induced suppressor of cytokine signalling-1 (SOCS-1), which formed a complex with Zap-70 after stimulation via TCR, and inhibition of SOCS-1 expression by SOCS-1-specific small interfering RNA reinstated TCR-mediated activation of NFAT in cells pre-stimulated with flagellin. These results collectively indicate that bacterial flagellin inhibits TCR-mediated activation of T cells by inducing SOCS-1.
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Affiliation(s)
- Shu Okugawa
- Department of Infectious Diseases, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
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Ramos Moreno AC, Cabilio Guth BE, Baquerizo Martinez M. Can the fliC PCR-restriction fragment length polymorphism technique replace classic serotyping methods for characterizing the H antigen of enterotoxigenic Escherichia coli strains? J Clin Microbiol 2006; 44:1453-8. [PMID: 16597876 PMCID: PMC1448681 DOI: 10.1128/jcm.44.4.1453-1458.2006] [Citation(s) in RCA: 20] [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
In this study, we performed fliC PCR-restriction fragment length polymorphism (RFLP) to investigate whether this technique would be better than classic serotyping for the characterization of the H antigen in enterotoxigenic Escherichia coli (ETEC) strains. We showed that the fliC genes from ETEC strains can be characterized by restriction analysis of their polymorphism. Only one allele of the fliC gene from ETEC strains was found for each flagellar antigen, with the exception of H21. Nonmotile strains could also be characterized using this molecular technique. Moreover, determination of the somatic antigen was guided by the identification of the flagellar antigen from previously unknown serotypes of ETEC strains by PCR-RFLP, thus reducing the number of anti-antigen O sera used. The PCR-RFLP technique proved to be faster than classic serotyping for the characterization of the E. coli H antigen, taking 2 days to complete instead of the 7 or more days using classic serotyping. In conclusion, the H molecular typing for Enterobacteriaceae members may become an important epidemiological tool for the characterization of the H antigen of E. coli pathotypes. The PCR-RFLP technique is capable of guiding the determination of the H antigen and could partially replace seroagglutination. With the determination of the molecular profiles of alleles from strains obtained in epidemiological studies, new patterns will be described for ETEC strains or other E. coli pathotypes, thus permitting widespread use of this technique to characterize fliC genes and determine the H antigen of E. coli strains.
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Abstract
The chronic inflammatory bowel diseases Crohn's disease and ulcerative colitis are common causes of gastrointestinal disease in northern Europe, affecting as many as one in 250 people. Although mortality is low, morbidity associated with these diseases is substantial. We review the recent advances in the genetics of inflammatory bowel disease, with particular emphasis on the data that have been generated since the discovery of the CARD15 (NOD2) gene in 2001.
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Affiliation(s)
- Daniel R Gaya
- Gastrointestinal Unit, Molecular Medicine Centre, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU, UK
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