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Kentache T, Ben Abdelkrim A, Jouenne T, Dé E, Hardouin J. Global Dynamic Proteome Study of a Pellicle-forming Acinetobacter baumannii Strain. Mol Cell Proteomics 2017; 16:100-112. [PMID: 27799293 PMCID: PMC5217776 DOI: 10.1074/mcp.m116.061044] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 09/23/2016] [Indexed: 12/21/2022] Open
Abstract
For several decades, many bacteria, among which A. baumannii, have shown their ability to colonize the upper surface of static liquids, forming a biofilm at the air-liquid interface named pellicle. Despite the ubiquity of these pellicles in both natural and artificial environments, few studies have investigated this biofilm type. The present data set provides the first description of the whole proteome of A. baumannii cells grown as pellicle, using a label-free mass spectrometry approach. Results are in accord with the general findings reporting that sessile bacteria are far more resistant to detrimental conditions than their planktonic counterparts, by the accumulation of stress proteins. The present investigation also confirmed previous studies suggesting a correlation between the pellicle forming ability and the bacterial virulence. Indeed, we showed the up-regulation of numerous virulence factors during the pellicle growth, e.g. phospholipases, adhesion factors, as well as those of the GacAS Two-Component System (TCS) and Type 6 Secretion System (T6SS). We also highlighted that Bam and Tam systems, both related to the OM insertion machinery, play a critical role during pellicle biogenesis. Moreover, sessile bacteria activate several pathways, e.g. iron, magnesium, phosphate pathways, which allows for increasing the panel of nutrient sources.
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Affiliation(s)
- Takfarinas Kentache
- From the ‡CNRS; UMR 6270 Polymères, Biopolymères, Surfaces Laboratory, F-76821 Mont-Saint-Aignan, France
- §Normandie University, UR, France
| | - Ahmed Ben Abdelkrim
- From the ‡CNRS; UMR 6270 Polymères, Biopolymères, Surfaces Laboratory, F-76821 Mont-Saint-Aignan, France
- §Normandie University, UR, France
| | - Thierry Jouenne
- From the ‡CNRS; UMR 6270 Polymères, Biopolymères, Surfaces Laboratory, F-76821 Mont-Saint-Aignan, France
- §Normandie University, UR, France
- ¶PISSARO proteomic facility, IRIB, F-76821 Mont-Saint-Aignan, France
| | - Emmanuelle Dé
- From the ‡CNRS; UMR 6270 Polymères, Biopolymères, Surfaces Laboratory, F-76821 Mont-Saint-Aignan, France
- §Normandie University, UR, France
- ¶PISSARO proteomic facility, IRIB, F-76821 Mont-Saint-Aignan, France
| | - Julie Hardouin
- From the ‡CNRS; UMR 6270 Polymères, Biopolymères, Surfaces Laboratory, F-76821 Mont-Saint-Aignan, France;
- §Normandie University, UR, France
- ¶PISSARO proteomic facility, IRIB, F-76821 Mont-Saint-Aignan, France
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Hutchinson J, Runge W, Mulvey M, Norris G, Yetman M, Valkova N, Villemur R, Lepine F. Burkholderia cepaciaInfections Associated With Intrinsically Contaminated Ultrasound Gel: The Role of Microbial Degradation of Parabens. Infect Control Hosp Epidemiol 2015; 25:291-6. [PMID: 15108725 DOI: 10.1086/502394] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractObjective:To describe an outbreak of serious nosocomialBurkholderia cepaciainfections occurring after transrectal prostate biopsy associated with ultrasound gel intrinsically contaminated with paraben-degrading microorganisms.Methods:A retrospective chart review prompted by a blood culture isolate ofB, cepacia.Identification of microorganisms in ultrasound gel in two Canadian centers and characterization by pulsed-field gel electrophoresis and assays for paraben degradation.Setting:Two Canadian university-affiliated, tertiary-care centers in Newfoundland and Alberta.Results:Six seriousB. cepaciainfections were identified at the two centers. Isolates ofB. cepaciarecovered from the blood of patients from both centers and the ultrasound gel used during the procedures were identical, confirming intrinsic contamination. Strains ofEnterobacter cloacaeisolated from ultrasound gel at the two centers were also identical. The ability to degrade parabens was proven for bothB. cepaciaandE. cloacaestrains recovered from the ultrasound gel.Conclusions:Ultrasound gel is a potential source of infection. Contamination occurs at the time of manufacture, with organisms that degrade parabens, which are commonly used as stabilizing agents. There are far-reaching implications for the infection control community.
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Affiliation(s)
- Jim Hutchinson
- Healthcare Corporation of St. John's, Newfoundland, Canada
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Suppiger A, Schmid N, Aguilar C, Pessi G, Eberl L. Two quorum sensing systems control biofilm formation and virulence in members of the Burkholderia cepacia complex. Virulence 2014; 4:400-9. [PMID: 23799665 PMCID: PMC3714132 DOI: 10.4161/viru.25338] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The Burkholderia cepacia complex (Bcc) consists of 17 closely related species that are problematic opportunistic bacterial pathogens for cystic fibrosis patients and immunocompromised individuals. These bacteria are capable of utilizing two different chemical languages: N-acyl homoserine lactones (AHLs) and cis-2-unsaturated fatty acids. Here we summarize the current knowledge of the underlying molecular architectures of these communication systems, showing how they are interlinked and discussing how they regulate overlapping as well as specific sets of genes. A particular focus is laid on the role of these signaling systems in the formation of biofilms, which are believed to be highly important for chronic infections. We review genes that have been implicated in the sessile lifestyle of this group of bacteria. The new emerging role of the intracellular second messenger cyclic dimeric guanosine monophosphate (c-di-GMP) as a downstream regulator of the fatty acid signaling cascade and as a key factor in biofilm formation is also discussed.
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Affiliation(s)
- Angela Suppiger
- Department of Microbiology, University of Zürich, Zürich, Switzerland
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Khan A, Asif H, Studholme DJ, Khan IA, Azim MK. Genome characterization of a novel Burkholderia cepacia complex genomovar isolated from dieback affected mango orchards. World J Microbiol Biotechnol 2013; 29:2033-44. [PMID: 23653265 DOI: 10.1007/s11274-013-1366-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Accepted: 04/27/2013] [Indexed: 12/31/2022]
Abstract
We characterized the genome of the antibiotic resistant, caseinolytic and non-hemolytic Burkholderia sp. strain TJI49, isolated from mango trees (Mangifera indica L.) with dieback disease. This isolate produced severe disease symptoms on the indicator plants. Next generation DNA sequencing and short-read assembly generated the 60X deep 7,631,934 nucleotide draft genome of Burkholderia sp. TJI49 which comprised three chromosomes and at least one mega plasmid. Genome annotation studies revealed a total 8,992 genes, out of which 8,940 were protein coding genes. Comparative genomics and phylogenetics identified Burkholderia sp. TJI49 as a distinct species of Burkholderia cepacia complex (BCC), closely related to B. multivorans ATCC17616. Genome-wide sequence alignment of this isolate with replicons of BCC members showed conservation of core function genes but considerable variations in accessory genes. Subsystem-based gene annotation identified the active presence of wide spread colonization island and type VI secretion system in Burkholderia sp. TJI49. Sequence comparisons revealed (a) 28 novel ORFs that have no database matches and (b) 23 ORFs with orthologues in species other than Burkholderia, indicating horizontal gene transfer events. Fold recognition of novel ORFs identified genes encoding pertactin autotransporter-like proteins (a constituent of type V secretion system) and Hap adhesion-like proteins (involved in cell-cell adhesion) in the genome of Burkholderia sp. TJI49. The genomic characterization of this isolate provided additional information related to the 'pan-genome' of Burkholderia species.
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Affiliation(s)
- Asifullah Khan
- Jamil-ur-Rahman Center for Genome Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, 75270, Pakistan
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Inhülsen S, Aguilar C, Schmid N, Suppiger A, Riedel K, Eberl L. Identification of functions linking quorum sensing with biofilm formation in Burkholderia cenocepacia H111. Microbiologyopen 2012; 1:225-42. [PMID: 22950027 PMCID: PMC3426421 DOI: 10.1002/mbo3.24] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Revised: 03/29/2012] [Accepted: 04/03/2012] [Indexed: 01/08/2023] Open
Abstract
Burkholderia cenocepacia has emerged as an important pathogen for patients suffering from cystic fibrosis (CF). Previous work has shown that this organism employs the CepIR quorum-sensing (QS) system to control the expression of virulence factors as well as the formation of biofilms. To date, however, very little is known about the QS-regulated virulence factors and virtually nothing about the factors that link QS and biofilm formation. Here, we have employed a combined transcriptomic and proteomic approach to precisely define the QS regulon in our model strain B. cenocepacia H111, a CF isolate. Among the identified CepR-activated loci, three were analyzed in better detail for their roles in biofilm development: (i) a gene cluster coding for the BclACB lectins, (ii) the large surface protein BapA, and (iii) a type I pilus. The analysis of defined mutants revealed that BapA plays a major role in biofilm formation on abiotic surfaces while inactivation of the type I pilus showed little effect both in a static microtitre dish-based biofilm assay and in flow-through cells. Inactivation of the bclACB lectin genes resulted in biofilms containing hollow microcolonies, suggesting that the lectins are important for biofilm structural development.
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Affiliation(s)
- Silja Inhülsen
- Department of Microbiology, Institute of Plant Biology, University of ZurichZollikerstrasse, 107, 8008 Zurich, Switzerland
| | - Claudio Aguilar
- Department of Microbiology, Institute of Plant Biology, University of ZurichZollikerstrasse, 107, 8008 Zurich, Switzerland
| | - Nadine Schmid
- Department of Microbiology, Institute of Plant Biology, University of ZurichZollikerstrasse, 107, 8008 Zurich, Switzerland
| | - Angela Suppiger
- Department of Microbiology, Institute of Plant Biology, University of ZurichZollikerstrasse, 107, 8008 Zurich, Switzerland
| | - Kathrin Riedel
- Institute of Microbiology, Ernst-Moritz-Arndt University of GreifswaldFriedrich-Ludwig-Jahn-Strasse 15, D-17487, Greifswald,, Germany
| | - Leo Eberl
- Department of Microbiology, Institute of Plant Biology, University of ZurichZollikerstrasse, 107, 8008 Zurich, Switzerland
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Transmissibility and infection control implications of Burkholderia cepacia in cystic fibrosis. Can J Infect Dis 2012; 9:177-82. [PMID: 22346540 DOI: 10.1155/1998/269157] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
OBJECTIVE To describe the microbiology and potential virulence factors of Burkholderia cepacia; to discuss the studies that have investigated its mode of transmission among cystic fibrosis patients; and to identify the major risk factors associated with acquisition of this pathogen inside and outside of the hospital environment. DATA SOURCES MEDLINE search of the literature published between 1986 and 1997 using the key words/subject words Pseudomonas cepacia, Burkholderia cepacia, cystic fibrosis, infection control and transmissibility, and the bibliography of selected papers. DATA EXTRACTION Selected studies examining epidemiology, microbiology, virulence factors and mode of transmission of B cepacia in cystic fibrosis. DATA SYNTHESIS AND CONCLUSIONS B cepacia is a multidrug-resistant Gram-negative bacillus that has recently been recognized as a major respiratory pathogen in patients with cystic fibrosis. Colonization by this organism can lead to rapid pulmonary deterioration and premature death. Recent studies based on genomic subtyping techniques have suggested that it can be transmitted from person to person. Close social contact and hospitalization have been identified as risk factors for cross-infection. With the implementation of strict infection control policies such as segregation according to colonization status, the rate of new colonization has substantially decreased in most cystic fibrosis treatment centres.
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Growth of Acinetobacter baumannii in pellicle enhanced the expression of potential virulence factors. PLoS One 2011; 6:e26030. [PMID: 22046254 PMCID: PMC3203104 DOI: 10.1371/journal.pone.0026030] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Accepted: 09/15/2011] [Indexed: 02/06/2023] Open
Abstract
Background Interestingly, Acinetobacter baumannii presents an enhanced capacity to form biofilms (also named pellicles) at the air-liquid interface as compared to the other Acinetobacter species. This characteristic questions the contribution of this phenotype to an increased risk of clinical infections by this pathogen. Methodology/Principal Findings By a proteomic approach using 2-D gel electrophoresis-LC-MS/MS mass spectrometry, we compared the membrane protein patterns of A. baumannii 77, a pellicle-forming clinical isolate, grown in planktonic and in sessile modes. We identified 52 proteins with a differential expression, including 32 up-regulated and 20 down-regulated in the pellicle state. Several proteins, differentially expressed during pellicle development, were of particular interest. We determined the over-expression of four siderophore iron uptake systems including the acinetobactin and enterobactin receptors and confirmed that the development of this type of biofilm is promoted by ferric ions. Two over-expressed proteins, CarO and an OprD-homologue, putative carbapenem-resistance associated porins, would be involved in the transport of specific compounds, like ornithine, a biosynthesis precursor of a siderophore from the hydroxamate family. We evidenced the overexpression of a lipase and a transporter of LCFA that may be involved in the recycling of lipids inside the pellicle matrix. Finally, we demonstrated both by proteomic and by AFM studies that this particular type of biofilm required multiple pili systems to maintain this cohesive structure at the air-liquid interface; two of these systems have never been described in A. baumannii. Conclusions/Significance Our study demonstrated that several proteins, overexpressed at a late state of pellicle development, could be potentially involved in virulence processes. Therefore, regarding the number of potential virulence factors that are over-expressed in this growth mode, the pellicle-forming clinical isolates should be kept under survey.
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Bosch A, Prieto C, Serra DO, Martina P, Stämmbler M, Naumann D, Schmitt J, Yantorno O. Type-IV pili spectroscopic markers: applications in the quantification of piliation levels in Moraxella bovis cells by a FT-IR ANN-based model. JOURNAL OF BIOPHOTONICS 2010; 3:522-533. [PMID: 20422659 DOI: 10.1002/jbio.201000027] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Type-IV pili are cell surface organelles found in a wide variety of Gram-negative bacteria. They have traditionally been detected by electron microscopy and ELISA techniques. However, these methodologies are not appropriate for the rapid discrimination and quantification of piliated and nonpiliated cells in industrial or field conditions. Here, the analysis of FT-IR spectra of piliated, nonpiliated and sheared Moraxella bovis cells, together with purified pili suspensions spectra, allowed the identification of 3 IR regions associated to spectroscopic markers of Type-IV pili: 1750-1600, 1450-1350 and 1280-950 cm(-1). Such IR-specific markers were found for piliated cells grown in different culture systems (liquid or solid media), independently of the strain or pili serotype. They were also sensitive to pili expression levels. Therefore, on the bases of these specific spectral features, an FT-IR ANN-based model was developed to classify piliation levels in 5 distinct groups. An overall classification rate of almost 90% demonstrates the strong potential of the ANN system developed to monitor M. bovis cultures in vaccine production.
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Affiliation(s)
- Alejandra Bosch
- Centro de Investigación y Desarrollo en Fermentaciones Industriales CINDEFI, UNLP, CONICET La Plata, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, La Plata, Argentina
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Coenye T. Social interactions in the Burkholderia cepacia complex: biofilms and quorum sensing. Future Microbiol 2010; 5:1087-99. [DOI: 10.2217/fmb.10.68] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Burkholderia cepacia complex bacteria are opportunistic pathogens that cause respiratory tract infections in susceptible patients, mainly people with cystic fibrosis. There is convincing evidence that B. cepacia complex bacteria can form biofilms, not only on abiotic surfaces (e.g., glass and plastics), but also on biotic surfaces such as epithelial cells, leading to the suggestion that biofilm formation plays a key role in persistent infection of cystic fibrosis lungs. This article presents an overview of the molecular mechanisms involved in B. cepacia complex biofilm formation, the increased resistance of sessile B. cepacia complex cells and the role of quorum sensing in B. cepacia complex biofilm formation.
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Affiliation(s)
- Tom Coenye
- Laboratory of Pharmaceutical Microbiology, Ghent University, Harelbekestraat 72, B-9000 Gent, Belgium
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Ammendolia MG, Bertuccini L, Iosi F, Minelli F, Berlutti F, Valenti P, Superti F. Bovine lactoferrin interacts with cable pili of Burkholderia cenocepacia. Biometals 2010; 23:531-42. [DOI: 10.1007/s10534-010-9333-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2010] [Accepted: 03/25/2010] [Indexed: 12/01/2022]
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Abstract
Bacteria infect the respiratory tract early in the course of cystic fibrosis disease, often fail to be eradicated, and together with an aggressive host inflammatory response, are thought to be key players in the irreversible airway damage from which most patients ultimately die. Although incompletely understood, certain aspects of the cystic fibrosis airway itself appear to favor the development of chronic modes of survival, in particular biofilm formation; this and the development of antibiotic resistance following exposure to multiple antibiotic courses lead to chronic, persistent infection. In addition to the common cystic fibrosis pathogens, such as Staphylococcus aureus, Haemophilus influenzae, and Pseudomonas aeruginosa, several newer species are becoming more common. Furthermore, new molecular techniques have led to the identification of multiple different organisms within respiratory secretions, many of which are not cultured with conventional tools. Future work should aim to develop clinically applicable methods to identify these and to determine which have the potential to impact pulmonary health. We outline the basic tenets of infection control and treatment.
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Affiliation(s)
- Jane C Davies
- Department of Gene Therapy, Imperial College, Emmanuel Kaye Building, Manresa Road, London SW3 6NP, United Kingdom.
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The genome of Burkholderia cenocepacia J2315, an epidemic pathogen of cystic fibrosis patients. J Bacteriol 2008; 191:261-77. [PMID: 18931103 PMCID: PMC2612433 DOI: 10.1128/jb.01230-08] [Citation(s) in RCA: 273] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Bacterial infections of the lungs of cystic fibrosis (CF) patients cause major complications in the treatment of this common genetic disease. Burkholderia cenocepacia infection is particularly problematic since this organism has high levels of antibiotic resistance, making it difficult to eradicate; the resulting chronic infections are associated with severe declines in lung function and increased mortality rates. B. cenocepacia strain J2315 was isolated from a CF patient and is a member of the epidemic ET12 lineage that originated in Canada or the United Kingdom and spread to Europe. The 8.06-Mb genome of this highly transmissible pathogen comprises three circular chromosomes and a plasmid and encodes a broad array of functions typical of this metabolically versatile genus, as well as numerous virulence and drug resistance functions. Although B. cenocepacia strains can be isolated from soil and can be pathogenic to both plants and man, J2315 is representative of a lineage of B. cenocepacia rarely isolated from the environment and which spreads between CF patients. Comparative analysis revealed that ca. 21% of the genome is unique in comparison to other strains of B. cenocepacia, highlighting the genomic plasticity of this species. Pseudogenes in virulence determinants suggest that the pathogenic response of J2315 may have been recently selected to promote persistence in the CF lung. The J2315 genome contains evidence that its unique and highly adapted genetic content has played a significant role in its success as an epidemic CF pathogen.
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Fourier transform infrared spectroscopy for rapid identification of nonfermenting gram-negative bacteria isolated from sputum samples from cystic fibrosis patients. J Clin Microbiol 2008; 46:2535-46. [PMID: 18550747 DOI: 10.1128/jcm.02267-07] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The accurate and rapid identification of bacteria isolated from the respiratory tract of patients with cystic fibrosis (CF) is critical in epidemiological studies, during intrahospital outbreaks, for patient treatment, and for determination of therapeutic options. While the most common organisms isolated from sputum samples are Pseudomonas aeruginosa, Staphylococcus aureus, and Haemophilus influenzae, in recent decades an increasing fraction of CF patients has been colonized by other nonfermenting (NF) gram-negative rods, such as Burkholderia cepacia complex (BCC) bacteria, Stenotrophomonas maltophilia, Ralstonia pickettii, Acinetobacter spp., and Achromobacter spp. In the present study, we developed a novel strategy for the rapid identification of NF rods based on Fourier transform infrared spectroscopy (FTIR) in combination with artificial neural networks (ANNs). A total of 15 reference strains and 169 clinical isolates of NF gram-negative bacteria recovered from sputum samples from 150 CF patients were used in this study. The clinical isolates were identified according to the guidelines for clinical microbiology practices for respiratory tract specimens from CF patients; and particularly, BCC bacteria were further identified by recA-based PCR followed by restriction fragment length polymorphism analysis with HaeIII, and their identities were confirmed by recA species-specific PCR. In addition, some strains belonging to genera different from BCC were identified by 16S rRNA gene sequencing. A standardized experimental protocol was established, and an FTIR spectral database containing more than 2,000 infrared spectra was created. The ANN identification system consisted of two hierarchical levels. The top-level network allowed the identification of P. aeruginosa, S. maltophilia, Achromobacter xylosoxidans, Acinetobacter spp., R. pickettii, and BCC bacteria with an identification success rate of 98.1%. The second-level network was developed to differentiate the four most clinically relevant species of BCC, B. cepacia, B. multivorans, B. cenocepacia, and B. stabilis (genomovars I to IV, respectively), with a correct identification rate of 93.8%. Our results demonstrate the high degree of reliability and strong potential of ANN-based FTIR spectrum analysis for the rapid identification of NF rods suitable for use in routine clinical microbiology laboratories.
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Abstract
Nearly 2,000 ribotyping-based studies exist, ranging from epidemiology to phylogeny and taxonomy. None precisely reveals the molecular genetic basis, with many incorrectly attributing detected polymorphisms to rRNA gene sequences. Based on in silico genomics, we demonstrate that ribotype polymorphisms result from sequence variability in neutral housekeeping genes flanking rRNA operons, with rRNA gene sequences serving solely as conserved, flank-linked tags. We also reveal that from such an informatics perspective, it is readily feasible a priori to design an interpretable ribotyping scheme for a genomically sequenced microbial species, and we discuss limitations to the basic restriction fragment length polymorphism-based method as well as alternate PCR ribotyping-based schemes.
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Differential interaction of bacterial species from the Burkholderia cepacia complex with human airway epithelial cells. Microbes Infect 2007; 10:52-9. [PMID: 18068390 DOI: 10.1016/j.micinf.2007.10.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2006] [Revised: 10/03/2007] [Accepted: 10/03/2007] [Indexed: 01/01/2023]
Abstract
To increase knowledge of the pathogenic potential of the Burkholderia cepacia complex (BCC), we investigated the effects of reference strains of the nine BCC species on human bronchial epithelial cells in vitro. B. multivorans exhibited the highest rates of adherence to and internalization by host cells. Two out of three clinical isolates recovered from cystic fibrosis patients confirmed the B. multivorans high adhesiveness. All four B. multivorans isolates exhibited an aggregated pattern of adherence but any of them expressed cable pili. When bacteria were centrifuged onto cell cultures to circumvent their poor adhesiveness, B. pyrrocinia exhibited the highest internalization rate, followed by B. multivorans. The percentages of apoptotic cells in cultures infected with B. cepacia, B. multivorans, B. cenocepacia (subgroups IIIA and IIIB), B. stabilis and B. vietnamiensis were significantly higher than in control non-infected cultures. All nine BCC species triggered a similar release of the inflammatory cytokine IL-8, that was not reduced by cell treatment with cytochalasin D. Hence, our data demonstrate, for the first time, that all BCC species exhibit a similar ability to induce the expression of host immune mediators whereas they differ on their ability to adhere to, invade and kill airway epithelial cells.
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Lee YA, Chan CW. Molecular Typing and Presence of Genetic Markers Among Strains of Banana Finger-Tip Rot Pathogen, Burkholderia cenocepacia, in Taiwan. PHYTOPATHOLOGY 2007; 97:195-201. [PMID: 18944375 DOI: 10.1094/phyto-97-2-0195] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
ABSTRACT Burkholderia cenocepacia (genomovar III of B. cepacia complex), the causal agent of banana finger-tip rot, is a common plant-associated bacterium but also an important opportunistic pathogen of humans. To better understand the nature of B. cenocepacia from banana, the genetic variation among B. cenocepacia isolates from various banana-growing regions in southern Taiwan was examined. Forty-four serial isolates recovered from diseased banana stigmata from three banana-growing regions during the periods ranging from 2002 to 2004 were investigated. All B. cenocepacia isolates picked from quinate-yeast extract tetracycline-polymyxin semiselective medium could cause onion maceration and were polymerase chain reaction (PCR) positive for bcscV, which is a type III secretion gene present in all members of the B. cepacia complex except B. cepacia (formerly genomovar I). Genetic diversity was assessed using recA PCR restriction fragment length polymorphism, recA nucleotide sequence analysis, and pulsed-field gel electrophoresis assays. The assays revealed the genetic variability among the isolates and also allowed us to trace the relationship among isolates. The isolates all were assigned to genomovar III and consisted of two groups, A and B, which corresponded to recA lineage IIIA and IIIB. The group B strains were separated into B1 and B2 subgroups and the B1 strains were further divided into distinct lineages. The B1 strains were the most frequently detected and occurred in all regions tested. There was no significant difference between strains from each subgroup in the virulence on banana fingers of cv. Cavendish. PCR assays were further used to determine whether B. cenocepacia from banana contained the cable pilus subunit gene (cblA), IS1356, and B. cepacia epidemic strain marker (BCESM), which are DNA markers associated with epidemic B. cepacia clinic strains. The results indicated that cblA and IS1356 were absent but the BCESM was found in all isolates. The present study revealed that banana is a natural reservoir of genetically diversified B. cenocepacia strains.
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Waters V, Ratjen F. Multidrug-resistant organisms in cystic fibrosis: management and infection-control issues. Expert Rev Anti Infect Ther 2007; 4:807-19. [PMID: 17140357 DOI: 10.1586/14787210.4.5.807] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Chronic infection and inflammation are the hallmarks of cystic fibrosis lung disease. As cystic fibrosis patients are living longer owing to more intense treatment, multidrug-resistant organisms are being isolated increasingly from patients' respiratory tracts. While the adverse effects of Pseudomonas aeruginosa and Burkholderia cepacia complex are well described, less is known about the clinical significance of other emerging multidrug-resistant organisms, such as methicillin-resistant Staphylococcus aureus and Stenotrophomonas maltophilia. Owing to multiple mechanisms of antimicrobial resistance, these organisms are difficult to treat and often require combination antibiotic therapy. Until more is known about their pathogenicity and effect on clinical outcomes, physicians should be aware of the potential transmissibility of these organisms and implement adequate infection control strategies.
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Affiliation(s)
- Valerie Waters
- Division of Infectious Diseases, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, M5G 1X8 Canada
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Ubbink J, Schär-Zammaretti P. Probing bacterial interactions: integrated approaches combining atomic force microscopy, electron microscopy and biophysical techniques. Micron 2005; 36:293-320. [PMID: 15857770 DOI: 10.1016/j.micron.2004.11.005] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2004] [Revised: 11/24/2004] [Accepted: 11/25/2004] [Indexed: 11/27/2022]
Abstract
Recent developments in the application of Atomic Force Microscopy (AFM) and other biophysical techniques for the study of bacterial interactions and adhesion are discussed in the light of established biological and microscopic approaches. Whereas molecular-biological techniques combined with electron microscopy allow the identification and localization of surface constituents mediating bacterial interactions, with AFM it has become possible to actually measure the forces involved in bacterial interactions. Combined with the flexibility of AFM in probing various types of physical interactions, such as electrostatic interactions, specific ligand-receptor interactions and the elastic forces of deformation and extension of bacterial surface polymers and cell wall, this provides prospects for the elucidation of the biophysical mechanism of bacterial interaction. However, because of the biochemical and a biophysical complexity of the bacterial cell wall, integrated approaches combining AFM with electron microscopy and biophysical techniques are needed to elucidate the mechanism by which a bacterium interacts with a host or material surface. The literature on electron microscopy of the bacterial cell wall is reviewed, with particular emphasis on the staining of specific classes of cell-wall constituents. The application of AFM in the analysis of bacterial surfaces is discussed, including AFM operating modes, sample preparation methods and results obtained on various strains. For various bacterial strains, the integration of EM and AFM data is discussed. Various biophysical aspects of the analysis of bacterial surface structure and interactions are discussed, including the theory of colloidal interactions and Bell's theory of cell-to-cell adhesion. An overview is given of biophysical techniques used in the analysis of the properties of bacterial surfaces and bacterial surface constituents and their integration with AFM. Finally, we discuss recent progress in the understanding of the role of bacterial interactions in medicine within the framework of the techniques and concepts discussed in the paper.
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Affiliation(s)
- Job Ubbink
- Nestlé Research Center, Vers-chez-les-Blanc, P.O. Box 44, CH-1000 Lausanne 26, Switzerland.
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Mahenthiralingam E, Urban TA, Goldberg JB. The multifarious, multireplicon Burkholderia cepacia complex. Nat Rev Microbiol 2005; 3:144-56. [PMID: 15643431 DOI: 10.1038/nrmicro1085] [Citation(s) in RCA: 622] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The Burkholderia cepacia complex (Bcc) is a collection of genetically distinct but phenotypically similar bacteria that are divided into at least nine species. Bcc bacteria are found throughout the environment, where they can have both beneficial and detrimental effects on plants and some members can also degrade natural and man-made pollutants. Bcc bacteria are now recognized as important opportunistic pathogens that can cause variable lung infections in cystic fibrosis patients, which result in asymptomatic carriage, chronic infection or 'cepacia syndrome', which is characterized by a rapid decline in lung function that can include invasive disease. Here we highlight the unique characteristics of the Bcc, focusing on the factors that determine virulence.
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21
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Plesa M, Kholti A, Vermis K, Vandamme P, Panagea S, Winstanley C, Cornelis P. Conservation of the opcL gene encoding the peptidoglycan-associated outer-membrane lipoprotein among representatives of the Burkholderia cepacia complex. J Med Microbiol 2004; 53:389-398. [PMID: 15096547 DOI: 10.1099/jmm.0.05504-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Members of the Burkholderia cepacia complex are Gram-negative β-proteobacteria that are classified into nine genomic species or genomovars. Some representatives of this group of bacteria, such as Burkholderia multivorans (genomovar II) and Burkholderia cenocepacia (genomovar III), are considered to be dangerous pathogens for cystic fibrosis (CF) patients because of their capacity to colonize CF lungs. The opcL gene, which encodes the peptidoglycan-associated outer-membrane lipoprotein (PAL), was detected in the genome of Burkholderia sp. LB 400 by a similarity search that was based on the sequence of the Pseudomonas aeruginosa PAL, OprL. Primers that could amplify part of opcL from B. multivorans LMG 13010T were designed. This PCR fragment was used as a probe for screening of a B. multivorans genomic bank, allowing cloning of the complete opcL gene. The complete opcL gene could be PCR-amplified from DNA from all genomovars. The sequences of these opcL genes showed a high degree of conservation (> 95 %) among different species of the B. cepacia complex. OpcL protein that was purified from B. multivorans LMG 13010T was used to generate mouse polyclonal antisera against OpcL. The OpcL protein could be produced in Escherichia coli and detected in outer-membrane fractions by Western blot. Burkholderia cells were labelled by immunofluorescence staining using antibodies against OpcL, but only after treatment with EDTA and SDS. The opcL gene could be amplified directly from the sputa of 15 CF patients who were known to be colonized by B. cepacia; sequence data derived from the amplicons identified the colonizing strains as B. cenocepacia (genomovar III, n = 14) and B. multivorans (n = 1).
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Affiliation(s)
- Maria Plesa
- Laboratory of Microbial Interactions, Department of Molecular and Cellular Interactions, Flanders Interuniversity Institute of Biotechnology, Vrije Universiteit Brussel, Building E, Room 6.2, Pleinlaan 2, B-1050 Brussels, Belgium 2,3Laboratory of Pharmaceutical Microbiology2 and Laboratory of Microbiology3, Ghent University, Ghent, Belgium 4Department of Medical Microbiology and Genitourinary Medicine, University of Liverpool, Duncan Building, Liverpool L69 3GA, UK
| | - Abdelaziz Kholti
- Laboratory of Microbial Interactions, Department of Molecular and Cellular Interactions, Flanders Interuniversity Institute of Biotechnology, Vrije Universiteit Brussel, Building E, Room 6.2, Pleinlaan 2, B-1050 Brussels, Belgium 2,3Laboratory of Pharmaceutical Microbiology2 and Laboratory of Microbiology3, Ghent University, Ghent, Belgium 4Department of Medical Microbiology and Genitourinary Medicine, University of Liverpool, Duncan Building, Liverpool L69 3GA, UK
| | - Karen Vermis
- Laboratory of Microbial Interactions, Department of Molecular and Cellular Interactions, Flanders Interuniversity Institute of Biotechnology, Vrije Universiteit Brussel, Building E, Room 6.2, Pleinlaan 2, B-1050 Brussels, Belgium 2,3Laboratory of Pharmaceutical Microbiology2 and Laboratory of Microbiology3, Ghent University, Ghent, Belgium 4Department of Medical Microbiology and Genitourinary Medicine, University of Liverpool, Duncan Building, Liverpool L69 3GA, UK
| | - Peter Vandamme
- Laboratory of Microbial Interactions, Department of Molecular and Cellular Interactions, Flanders Interuniversity Institute of Biotechnology, Vrije Universiteit Brussel, Building E, Room 6.2, Pleinlaan 2, B-1050 Brussels, Belgium 2,3Laboratory of Pharmaceutical Microbiology2 and Laboratory of Microbiology3, Ghent University, Ghent, Belgium 4Department of Medical Microbiology and Genitourinary Medicine, University of Liverpool, Duncan Building, Liverpool L69 3GA, UK
| | - Stavroula Panagea
- Laboratory of Microbial Interactions, Department of Molecular and Cellular Interactions, Flanders Interuniversity Institute of Biotechnology, Vrije Universiteit Brussel, Building E, Room 6.2, Pleinlaan 2, B-1050 Brussels, Belgium 2,3Laboratory of Pharmaceutical Microbiology2 and Laboratory of Microbiology3, Ghent University, Ghent, Belgium 4Department of Medical Microbiology and Genitourinary Medicine, University of Liverpool, Duncan Building, Liverpool L69 3GA, UK
| | - Craig Winstanley
- Laboratory of Microbial Interactions, Department of Molecular and Cellular Interactions, Flanders Interuniversity Institute of Biotechnology, Vrije Universiteit Brussel, Building E, Room 6.2, Pleinlaan 2, B-1050 Brussels, Belgium 2,3Laboratory of Pharmaceutical Microbiology2 and Laboratory of Microbiology3, Ghent University, Ghent, Belgium 4Department of Medical Microbiology and Genitourinary Medicine, University of Liverpool, Duncan Building, Liverpool L69 3GA, UK
| | - Pierre Cornelis
- Laboratory of Microbial Interactions, Department of Molecular and Cellular Interactions, Flanders Interuniversity Institute of Biotechnology, Vrije Universiteit Brussel, Building E, Room 6.2, Pleinlaan 2, B-1050 Brussels, Belgium 2,3Laboratory of Pharmaceutical Microbiology2 and Laboratory of Microbiology3, Ghent University, Ghent, Belgium 4Department of Medical Microbiology and Genitourinary Medicine, University of Liverpool, Duncan Building, Liverpool L69 3GA, UK
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Petrucca A, Cipriani P, Valenti P, Santapaola D, Cimmino C, Scoarughi GL, Santino I, Stefani S, Sessa R, Nicoletti M. Molecular characterization of Burkholderia cepacia isolates from cystic fibrosis (CF) patients in an Italian CF center. Res Microbiol 2003; 154:491-8. [PMID: 14499935 DOI: 10.1016/s0923-2508(03)00145-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Bacteria of the Burkholderia cepacia complex consist of a number of closely related genomic species (genomovars) potentially pathogenic for cystic fibrosis (CF) patients, collectively referred to as the B. cepacia complex. The genomovar status and epidemiological relatedness of B. cepacia complex strains recovered from CF patients, attending a CF Center at the University Hospital "Policlinico Umberto I" of Rome, were investigated using 16S rRNA PCR-RFLP, recA PCR-RFLP, genomovar-specific PCR, and RAPD. Forty-seven isolates identified as B. cepacia by commercial systems were repeatedly recovered from 19 CF patients. The taxonomy approach used in this study showed that 17 of the 19 patients were colonized by B. cepacia complex strains. Genomovar III (11 strains) was the most prevalent genomovar. Two strains of genomovar I, one B. stabilis (genomovar IV), one B. multivorans (genomovar II), and 4 strains of B. anthina (genomovar VIII) were also identified. This is the first report of multiple patient colonization by B. anthina in a CF center. The epidemiological and genetic relatedness as well as the presence of molecular markers associated with virulence and transmissibility of the B. cepacia complex strains were determined and probable patient-to-patient spread was observed.
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Affiliation(s)
- Andrea Petrucca
- Azienda Ospedaliera Sant'Andrea, Laboratorio di Microbiologia Clinica, Via di Grottarossa 1035, 00189 Rome, Italy
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23
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Detsika MG, Corkill JE, Magalhães M, Glendinning KJ, Hart CA, Winstanley C. Molecular typing of, and distribution of genetic markers among, Burkholderia cepacia complex isolates from Brazil. J Clin Microbiol 2003; 41:4148-53. [PMID: 12958239 PMCID: PMC193793 DOI: 10.1128/jcm.41.9.4148-4153.2003] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PCR tests were used to assign genomovar status to 39 non-cystic fibrosis (non-CF) and 11 CF Burkholderia cepacia complex isolates from patients in hospitals in Recife, Brazil. Non-CF isolates were assigned to genomovar IIIA (71.8%), genomovar I (15.4%), B. vietnamiensis (7.7%), and B. multivorans (5.1%). CF isolates were assigned to genomovar IIIA (18.2%), B. vietnamiensis (18.2%), and genomovar I (9.1%). Six CF isolates sharing recA PCR-restriction fragment length polymorphism (RFLP) and randomly amplified polymorphic DNA (RAPD) patterns could not be assigned to a genomovar. 16S rDNA sequence obtained from these isolates indicated a closest relationship to B. anthina, but the recA sequence was equally divergent from several genomovars. PCR screening indicated the presence of cblA in only two isolates, whereas the B. cepacia epidemic strain marker was found in 22 of 28 genomovar IIIA isolates. A type III secretion gene was detected in all but genomovar I isolates. RAPD and PCR-RFLP assays, targeting both recA and fliC, indicated a large amount of genetic variability among the isolates, with many novel patterns being observed. Nine genomovar IIIA isolates from different non-CF patients and clinical sources had identical genotypes, indicating the presence of a common clone.
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Affiliation(s)
- Maria G Detsika
- Department of Medical Microbiology and Genitourinary Medicine, University of Liverpool, Liverpool L69 3GA, United Kingdom
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24
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Cody AJ, Field D, Feil EJ, Stringer S, Deadman ME, Tsolaki AG, Gratz B, Bouchet V, Goldstein R, Hood DW, Moxon ER. High rates of recombination in otitis media isolates of non-typeable Haemophilus influenzae. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2003; 3:57-66. [PMID: 12797973 PMCID: PMC2728426 DOI: 10.1016/s1567-1348(02)00152-1] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Non-typeable (NT) or capsule-deficient, Haemophilus influenzae (Hi) is a common commensal of the upper respiratory tract of humans and can be pathogenic resulting in diseases such as otitis media, sinusitis and pneumonia. The lipopolysaccharide (LPS) of NTHi is a major virulence factor that displays substantial intra-strain and inter-strain variation of its oligosaccharide structures. To investigate the genetic basis of LPS variation we sequenced internal regions of each of seven genes required for the biosynthesis of either the inner or the outer core oligosaccharide structures. These sequences were obtained from 25 representative NTHi isolates from episodes of otitis media. We found abundant evidence of recombination among LPS genes of NTHi, a finding in marked contrast to previous analyses of biosynthetic genes for capsular polysaccharide, a well-documented virulence factor of Hi. We found mosaic sequences, linkage equilibrium between loci and a lack of congruence between gene trees. These high rates were not confined to LPS genes since evidence for similar amounts of recombination was also found in eight housekeeping genes in a subset of the same 25 isolates. These findings provide a population based foundation for a better understanding of the role of NTHi LPS as a virulence factor and its potential as a candidate vaccine.
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Affiliation(s)
- Alison J Cody
- Molecular Infectious Diseases Group, Department of Paediatrics, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK.
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25
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Crowley D, Daly M, Lucey B, Shine P, Collins JJ, Cryan B, Moore JE, Murphy P, Buckley G, Fanning S. Molecular epidemiology of cystic fibrosis-linked Burkholderia cepacia complex isolates from three national referral centres in Ireland. J Appl Microbiol 2002; 92:992-1004. [PMID: 11972706 DOI: 10.1046/j.1365-2672.2002.01612.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIMS Burkholderia cepacia is a Gram-negative bacterium associated with increasing morbidity and mortality and is readily transmitted among infected cystic fibrosis (CF) patients. The B. cepacia complex consists of five distinct subgroups, termed genomovars. A collection of 17 presumptive B. cepacia isolates, obtained from three national CF referral centres located in different geographical regions in Ireland, was studied. The aim of this study was to investigate these isolates using molecular subtyping protocols for evidence of genetic relationships and for the presence of antibiotic resistance-encoding class 1 integron structures. METHODS AND RESULTS Genomovar classifications were assigned to each isolate based on HaeIII enzyme profiles of their recA locus. Genetic relationships among this collection were also assessed after restriction fragment length polymorphism (RFLP)-mediated analysis of the 16S rDNA locus and DNA amplification fingerprinting (DAF). The surface expression of the cable pilus gene (cblA) may facilitate an early step in the infection process. All isolates were tested by amplification strategies for this marker. Burkholderia cepacia is known to be resistant to several antimicrobial agents. Resistance typing showed that the majority were resistant to three or more common antimicrobial agents. Five of the 17 isolates were resistant to sulphonamide, a characteristic linked with the presence of class 1 integrons. Gene cassettes containing beta-lactamase (oxa) and aminoglycoside acetyltransferase (aac(6')-1a) encoding genes were identified by polymerase chain reaction amplification. CONCLUSIONS Most of the isolates in this study were classified as genomovar III and were indistinguishable based on their corresponding 16S rDNA-RFLP profiles, whilst DAF further subtyped the collection. The cblA marker was identified in 47% of the isolates, many of which clustered in the genomovar III group. Class 1 integrons with recombined gene cassettes containing bla-OXA and aac(6')-1a genes were identified. SIGNIFICANCE AND IMPACT OF THE STUDY This study demonstrates the application of molecular methods to investigate B. cepacia, a well-recognized human pathogen, cultured from Irish CF patients. Genomovar III was the most common genomic type identified. DNA fingerprinting further subtyped the latter isolates, facilitating a more detailed description of the molecular epidemiology. Drug resistance in these organisms can be explained, at least in part, by the presence of class 1 integrons. Development of targeted infection control strategies could be facilitated using these applied methods.
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Affiliation(s)
- D Crowley
- Molecular Diagnostics Unit, Cork Institute of Technology, Bishopstown, Cork, Ireland
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26
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Heath DG, Hohneker K, Carriker C, Smith K, Routh J, LiPuma JJ, Aris RM, Weber D, Gilligan PH. Six-year molecular analysis of Burkholderia cepacia complex isolates among cystic fibrosis patients at a referral center for lung transplantation. J Clin Microbiol 2002; 40:1188-93. [PMID: 11923329 PMCID: PMC140335 DOI: 10.1128/jcm.40.4.1188-1193.2002] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Over a 6-year period, Burkholderia cepacia complex species were isolated from cystic fibrosis (CF) patients receiving care at The University of North Carolina Hospitals (clinic CF patients) and from those referred from other treatment centers. Fifty-six isolates collected from 30 referred patients and 26 clinic CF patients were characterized by pulsed-field gel electrophoresis (PFGE) and were assayed by PCR to detect the cable pilin gene, cblA. PFGE results indicated that six separate clusters (clusters A to F) were present among the 56 isolates and that three clusters (clusters A, B, and E) consisted only of isolates from referred patients infected with B. cepacia complex isolates prior to referral. However, one cluster (cluster C) consisted of isolates from four CF patients, and hospital records indicate that this cluster began with an isolate that came from a referred patient and that spread to three clinic CF patients. Cluster D consisted of two isolates from clinic CF patients, and hospitalization records are consistent with nosocomial, patient-to-patient spread. cblA was present in only 4 of the 56 isolates and included isolates in cluster E from the referred patients. Our results indicate a lack of spread of a previously characterized, transmissible clone from referred patients to our clinic CF population. Only two instances of nosocomial, patient-to-patient spread could be documented over the 6-year period. An additional spread of an isolate (cluster F) from a referred patient to a clinic patient could not be documented as nosocomial and may have been the result of spread in a nonhospitalized setting. The majority (36 of 56) of our B. cepacia complex-infected CF patients harbor isolates with unique genotypes, indicating that a diversity of sources account for infection. These data suggest that CF patients infected with B. cepacia complex and referred for lung transplantation evaluation were not a major source of B. cepacia complex strains that infected our resident CF clinic population.
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Affiliation(s)
- David G Heath
- Clinical Microbiology-Immunology Laboratories, University of North Carolina Hospitals, Chapel Hill 27514, USA
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27
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Agodi A, Barchitta M, Gianninò V, Collura A, Pensabene T, Garlaschi ML, Pasquarella C, Luzzaro F, Sinatra F, Mahenthiralingam E, Stefani S. Burkholderia cepacia complex in cystic fibrosis and non-cystic fibrosis patients: identification of a cluster of epidemic lineages. J Hosp Infect 2002; 50:188-95. [PMID: 11886194 DOI: 10.1053/jhin.2001.1160] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This study was performed in order to compare Burkholderia cepacia complex strains from cystic fibrosis (CF) and non-CF patients at the genomovar, genetic and epidemiological levels. A total of 92 B. cepacia respiratory tract isolates were obtained from patients attending the following CF centres: Catania and Palermo, Sicily; Gualdo Tadino, Central Italy, and Milan, Northern Italy. A total of 23 B. cepacia isolates were obtained from blood, surgical wound, and intravenous catheter sources of patients without CF, hospitalized in Catania and Varese, Northern Italy. Genomovar status identification, clonality and genetic relatedness determination, antibiotic susceptibility pattern determination and electron microscopy were performed. Transmission of infection was shown in both CF and non-CF patients by identifying clonality of responsible strains. In total 13 clones were involved in cross-transmission episodes. No outbreak was described involving both CF and non-CF patients. The present study indicates the existence of a distinct cluster of strains responsible for epidemics in CF and non-CF patients, based on their genetic relatedness, distinct from strains associated with no or negligible transmissibility. This result suggests that transmissibility is not only associated with a specific genomovar in CF patients, but also with a group of genetically related lineages in CF and non-CF patients. A key role is shown for both segregation measures and careful surveillance of infection, based on selective culture, molecular identification and epidemiological characterization of individual isolates.
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Affiliation(s)
- A Agodi
- Department of Biomedical Sciences, University of Catania, Italy
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28
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Abstract
There have been enormous improvements in life expectancy of patients with cystic fibrosis, especially with improved nutrition and better understanding of the basic cellular defects. However, infection in particular with Pseudomonas aeruginosa and Burkholderia cepacia, has the greatest effect in decreasing life expectancy. Although infections can be prevented by rigorous infection control procedures, early aggressive antimicrobial chemotherapy and established infection managed by antibiotics, they are not completely effective. A greater understanding of how the bacteria evade the host defences and produce infection is needed.
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Affiliation(s)
- C Anthony Hart
- Department of Medical Microbiology and Genitourinary Medicine, University of Liverpool, Liverpool, UK
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29
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Keig PM, Ingham E, Vandamme PAR, Kerr KG. Differential invasion of respiratory epithelial cells by members of the Burkholderia cepacia complex. Clin Microbiol Infect 2002; 8:47-9. [PMID: 11906501 DOI: 10.1046/j.1469-0691.2002.00356.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
To investigate whether there are differences between members of the Burkholderia cepacia complex in their ability to invade human respiratory epithelial cells, 11 strains belonging to genomovars I-V were studied in an antibiotic protection assay using the A549 cell line. Strains belonging to genomovars II and III were more invasive than those of genomovars I, IV and V. There was also intra-genomovar variation in invasiveness. No correlation between invasiveness and other putative virulence factors of importance in B. cepacia infection in individuals with cystic fibrosis, cable pilus and B. cepacia epidemic strain marker was identified.
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Affiliation(s)
- P M Keig
- Division of Microbiology, School of Biochemistry and Molecular Biology, University of Leeds, Leeds LS2 9JT, UK
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Chiu CH, Wong S, Hancock REW, Speert DP. Adherence of Burkholderia cepacia to respiratory tract epithelial cells and inhibition with dextrans. MICROBIOLOGY (READING, ENGLAND) 2001; 147:2651-2658. [PMID: 11577144 DOI: 10.1099/00221287-147-10-2651] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Adherence of Burkholderia cepacia to cells of the respiratory tract of patients with cystic fibrosis (CF) appears to be a necessary precondition for colonization and infection. To date, no effective anti-adhesive strategy has been devised for preventing B. cepacia infection in CF patients. It was found in this study that B. cepacia adhered to respiratory epithelial cells both in vitro and in vivo. However, strains with cable-like pili (Cbl) exhibited the typical clump formation on pneumocytes, whereas non-cable piliated strains predominantly showed single-cell adherence. Dextrans (nominally 4000-10000 Da) significantly inhibited adhesion of B. cepacia to A549 pneumocytes. When compared on an equal weight basis, the nominally 10000 Da dextran was most inhibitory. A dose-dependent inhibitory effect (up to 80 mg ml(-1)) was observed for most strains. Dextran exerted less of an anti-adhesive effect on the two Cbl+ strains than on the others which were Cbl-. Dextrans appeared to block the adherence in a non-specific fashion, as shown by the observations that the inhibitory effect was readily reversible and oligosaccharides composed of 2-4 glucose units with the same alpha-1,6 linkage were not inhibitory. The mean molecular masses of dextrans used in this study, as determined by gel filtration and MS, were approximately 10-fold lower than those indicated by the manufacturers. Our data suggest that dextran of nominal molecular mass 4000 Da at a concentration of 40 mg ml(-1) (10 mM according to manufacturer's quoted molecular mass) or more may be useful in patients with CF to prevent colonization and infection with B. cepacia.
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Affiliation(s)
- Cheng-Hsun Chiu
- Department of Paediatrics, Chang Gung Children's Hospital, Kweishan 333, Taoyuan, Taiwan1
| | - Simon Wong
- The Edward Jenner Institute for Vaccine Research, Compton, Newbury, Berkshire, UK2
| | - Robert E W Hancock
- Department of Microbiology and Immunology3, and Department of Paediatrics4, University of British Columbia, Vancouver, British Columbia, Canada
| | - David P Speert
- Department of Microbiology and Immunology3, and Department of Paediatrics4, University of British Columbia, Vancouver, British Columbia, Canada
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Abstract
Previous studies have indicated that pulmonary infection with Burkholderia cepacia is associated with poor clinical outcome after lung transplantation in cystic fibrosis (CF). Many treatment centers consider B. cepacia infection an absolute contraindication to lung transplantation. However, the B. cepacia complex actually consists of several closely related bacterial species. Although each of these has been isolated from CF sputum culture, certain species are much more frequently recovered than others, and it is not yet clear whether all species have the same potential for virulence in CF. Additional study is needed to better define the relative risks associated with each species of the B. cepacia complex.
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Affiliation(s)
- J J LiPuma
- Department of Pediatrics and Communicable Diseases, University of Michigan Medical School, Ann Arbor, Michigan 48109-0646, USA.
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32
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Agodi A, Mahenthiralingam E, Barchitta M, Gianninò V, Sciacca A, Stefani S. Burkholderia cepacia complex infection in Italian patients with cystic fibrosis: prevalence, epidemiology, and genomovar status. J Clin Microbiol 2001; 39:2891-6. [PMID: 11474009 PMCID: PMC88256 DOI: 10.1128/jcm.39.8.2891-2896.2001] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The prevalence, epidemiology, and genomovar status of Burkholderia cepacia complex strains recovered from Italian cystic fibrosis (CF) patients were investigated using genetic typing and species identification methods. Four CF treatment centers were examined: two in Sicily, one in central Italy, and one in northern Italy. B. cepacia complex bacteria were isolated from 59 out of 683 CF patients attending these centers (8.6%). For the two geographically related treatment centers in Sicily, there was a high incidence of infection caused by a single epidemic clone possessing the cblA gene and belonging to B. cepacia genomovar III, recA group III-A, closely related to the major North America-United Kingdom clone, ET12; instability of the cblA sequence was also demonstrated for clonal isolates. In summary, of all the strains of B. cepacia encountered in the Italian CF population, the genomovar III, recA group III-A strains were the most prevalent and transmissible. However, patient-to-patient spread was also observed with several other genomovars, including strains of novel taxonomic status within the B. cepacia complex. A combination of genetic identification and molecular typing analysis is recommended to fully define specific risks posed by the genomovar status of strains within the B. cepacia complex.
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Affiliation(s)
- A Agodi
- Department of Biomedical Sciences, Policlinico, University of Catania, Catania, Italy
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33
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Abstract
The Gram-negative bacterium Burkholderia cepacia has recently emerged as an important opportunistic pathogen in humans. This review focuses on the cellular aspects of B. cepacia infection and the dynamics of the B. cepacia-host cell interaction, including recent advances in our understanding of the ability of B. cepacia to adhere to, enter, and survive intracellularly within human cells.
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Affiliation(s)
- C D Mohr
- Department of Microbiology, University of Minnesota Medical School, Minneapolis Minnesota, 55455-0312, USA.
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Holmes A, Nolan R, Taylor R, Finley R, Riley M, Jiang RZ, Steinbach S, Goldstein R. An epidemic of burkholderia cepacia transmitted between patients with and without cystic fibrosis. J Infect Dis 1999; 179:1197-205. [PMID: 10191223 PMCID: PMC3325287 DOI: 10.1086/314699] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Burkholderia cepacia is an important pathogen in cystic fibrosis (CF) and an infrequent cause of nosocomial infection in non-CF patients. This report describes a large hospital outbreak that appeared to involve both patient groups, a previously unrecognized phenomenon. Ribotype restriction fragment length polymorphism (RFLP) profiles and pulsed-field gel electrophoresis-resolved macrochromosomal RFLPs were analyzed, a ribotype-based phylogenic tree was constructed, and case-control and cohort studies were performed. A single dominant clone was found in both CF and non-CF groups. Phylogenic analysis suggests that it has evolved independently and that such highly transmissible strains can emerge rapidly and randomly. Acquisition risk in the CF patients was linked to hospitalization (odds ratio=5.47, P=.0158, confidence interval=1. 28-26.86) and was associated with significantly increased mortality rates. Infection control policies must now consider this threat of transmission between non-CF and CF patients.
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Affiliation(s)
- A Holmes
- Department of Infectious Diseases, Hammersmith Hospital, London, W12 0NN, United Kingdom.
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Abstract
Although Burkholderia cepacia colonizes a relatively small proportion of individuals with cystic fibrosis (CF), it is associated with significant morbidity and mortality, and has had a profound impact on infection control practices. This article reviews the current understanding of the epidemiology of B. cepacia infection, describes important recent developments in the microbiology and taxonomy of this species, and presents issues that remain obstacles to defining the optimal management of B. cepacia infection in CF.
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Affiliation(s)
- J J LiPuma
- Department of Pediatrics, Allegheny University of the Health Sciences, Philadelphia, Pennsylvania, USA
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Tipper JL, Ingham E, Cove JH, Todd NJ, Kerr KG. Survival and multiplication of Burkholderia cepacia within respiratory epithelial cells. Clin Microbiol Infect 1998. [DOI: 10.1111/j.1469-0691.1998.tb00394.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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37
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Segonds C, Bingen E, Couetdic G, Mathy S, Brahimi N, Marty N, Plesiat P, Michel-Briand Y, Chabanon G. Genotypic analysis of Burkholderia cepacia isolates from 13 French cystic fibrosis centers. J Clin Microbiol 1997; 35:2055-60. [PMID: 9230381 PMCID: PMC229902 DOI: 10.1128/jcm.35.8.2055-2060.1997] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Burkholderia cepacia has been involved in outbreaks of pulmonary infection among patients with cystic fibrosis (CF), and the spread of a highly transmissible clone has been reported throughout the United Kingdom and Canada. These data prompted a DNA-based typing study of the strains recovered in French CF centers. Ninety-five isolates recovered from 71 patients attending 13 CF centers in 9 regions of France were characterized by randomly amplified polymorphic DNA (RAPD) analysis and pulsed-field gel electrophoresis (PFGE). Twenty-one genotypes were identified among the 95 isolates, and the results of RAPD and PFGE were concordant for 89 isolates (94%). Cross-colonization was demonstrated in 7 of the 13 CF centers. The investigation of serial isolates showed that most chronically colonized patients harbored a single B. cepacia strain. A geographically clustered distribution of B. cepacia genotypes was observed, except for one genotype, which was detected in four regions but was proven to be different from the genotype of the British-Canadian highly transmissible strain. The present study confirms the ability of B. cepacia to spread among CF communities in France and the importance of epidemiological surveys in the institution of prevention policies.
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Affiliation(s)
- C Segonds
- Laboratoire de Bactériologie-Virologie-Hygiène, CHU Rangueil, Toulouse, France
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Mahenthiralingam E, Simpson DA, Speert DP. Identification and characterization of a novel DNA marker associated with epidemic Burkholderia cepacia strains recovered from patients with cystic fibrosis. J Clin Microbiol 1997; 35:808-16. [PMID: 9157133 PMCID: PMC229681 DOI: 10.1128/jcm.35.4.808-816.1997] [Citation(s) in RCA: 146] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Burkholderia cepacia is a problematic pathogen that may spread among patients with cystic fibrosis (CF). One highly infectious CF strain that causes epidemics in both the United Kingdom and eastern Canada has been shown to possess both the cable pilin subunit gene (cblA) and a unique combination of insertion sequences. However, no genetic markers linking this strain type with other types epidemic at various centers have been identified. Using a randomly amplified polymorphic DNA (RAPD) typing scheme, we identified an apparently conserved 1.4-kb fragment in the DNA fingerprint of epidemic B. cepacia strains. Conservation of the DNA marker among epidemic strains was demonstrated by Southern hybridization, and its prevalence was assessed in a collection of chromosomal DNAs extracted from 627 isolates representative of 132 RAPD-defined B. cepacia strain types. The marker was specifically associated with seven epidemic CF strains, was absent among nonepidemic strains infecting individual patients with CF, and rare among strains recovered from the natural environment. Only one of the seven epidemic CF strain types possessed DNA homologous to cblA. The RAPD marker was designated the "B. cepacia epidemic strain marker" (BCESM). Sequence analysis of chromosomal DNA corresponding to the 1.4-kb RAPD marker revealed the presence of a putative open reading frame (ORF) with significant homology to several negative transcriptional regulators; the ORF was designated the "epidemic strain marker regulator," or esmR. The BCESM DNA is the first genetic marker that has been identified to be specifically associated with and conserved among several epidemic B. cepacia strains which infect multiple patients with CF.
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Affiliation(s)
- E Mahenthiralingam
- Department of Pediatrics, University of British Columbia, Vancouver, Canada
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Govan JR, Deretic V. Microbial pathogenesis in cystic fibrosis: mucoid Pseudomonas aeruginosa and Burkholderia cepacia. Microbiol Rev 1996; 60:539-74. [PMID: 8840786 PMCID: PMC239456 DOI: 10.1128/mr.60.3.539-574.1996] [Citation(s) in RCA: 838] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Respiratory infections with Pseudomonas aeruginosa and Burkholderia cepacia play a major role in the pathogenesis of cystic fibrosis (CF). This review summarizes the latest advances in understanding host-pathogen interactions in CF with an emphasis on the role and control of conversion to mucoidy in P. aeruginosa, a phenomenon epitomizing the adaptation of this opportunistic pathogen to the chronic chourse of infection in CF, and on the innate resistance to antibiotics of B. cepacia, person-to-person spread, and sometimes rapidly fatal disease caused by this organism. While understanding the mechanism of conversion to mucoidy in P. aeruginosa has progressed to the point where this phenomenon has evolved into a model system for studying bacterial stress response in microbial pathogenesis, the more recent challenge with B. cepacia, which has emerged as a potent bona fide CF pathogen, is discussed in the context of clinical issues, taxonomy, transmission, and potential modes of pathogenicity.
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Affiliation(s)
- J R Govan
- Department of Medical Microbiology, University of Edinburgh Medical School, Scotland
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Tyler SD, Rozee KR, Johnson WM. Identification of IS1356, a new insertion sequence, and its association with IS402 in epidemic strains of Burkholderia cepacia infecting cystic fibrosis patients. J Clin Microbiol 1996; 34:1610-6. [PMID: 8784555 PMCID: PMC229080 DOI: 10.1128/jcm.34.7.1610-1616.1996] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Burkholderia cepacia is now recognized as an important opportunistic pathogen in cystic fibrosis (CF) and other compromised patients. Epidemicity among CF patients has been attributed to at least one particularly infectious strain (strain ET12), and both genetic evidence and anecdotal evidence suggest that this strain, currently endemic in Ontario, and those causing an epidemic in the United Kingdom, are indeed the same. Our study was conducted to determine whether there was any association between the presence of various insertion sequence (IS) elements, the cable pilin subunit gene (cblA), electrophoretic type (ET), and ribotype (RT) in a collection of 97 clinical and 2 environmental isolates of B. cepacia. No apparent linkage was found for IS elements IS401, IS402, IS406, IS407, and IS408 with ET or RT. The cblA target, said to be a marker for high infectivity, was detected in 100% (38 of 38) of strains of B. cepacia ET12 and in a single strain of ET13 that differed in a single enzyme allele. A new IS, IS1356, identified during the investigation, was present in 71.7% of all isolates, and 50.7% of these isolates harbored IS1356 as a hybrid IS element inserted into IS402. IS1356 is 1,353 bp in length, and when it is inserted into IS402 it results in a 10-bp duplication at the site of insertion. IS1356 contains one major open reading frame of 1,260 bp coding for a putative transposase which has significant homology to ISRm3 in Rhizobium meliloti (59%) and to an undesignated IS element in Corynebacterium diphtheriae (49%). The IS402-IS1356 element was found exclusively in the epidemic strains from Ontario and the United Kingdom, being detected in 94.7% (36 of 38 isolates) of B. cepacia ET12 isolates. Of the two ET12 isolates found to be devoid of the IS402-IS1356 element, both contained IS1356 unassociated with IS402, one was temporally unrelated to the epidemic, and the other was from a CF patient in a geographic area remote from Ontario and the United Kingdom. It is evident that the IS402-IS1356 hybrid element, the cblA pilin subunit gene, and the allelic suite represented by multilocus enzyme electrophoretic type ET12 may provide useful markers for the epidemic, highly transmissible transatlantic strain isolated in Ontario and the United Kingdom.
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Affiliation(s)
- S D Tyler
- Bureau of Microbiology, Laboratory Centre for Disease Control, Ottawa, Ontario, Canada
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Sylvester FA, Sajjan US, Forstner JF. Burkholderia (basonym Pseudomonas) cepacia binding to lipid receptors. Infect Immun 1996; 64:1420-5. [PMID: 8606110 PMCID: PMC173935 DOI: 10.1128/iai.64.4.1420-1425.1996] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Piliated Burkholderia (formerly Pseudomonas) cepacia from sputa of cys tic fibrosis patients in Toronto, Canada, were shown earlier to bind to purified mucins and to a protein receptor on epithelial cells via a 22-kDa adhesin located on unique cable pili. However, a second receptor, thought to be lipid in nature, was also identified on cells and appeared to serve as the major cell receptor for poorly piliated or nonpiliated isolates. In the present study in vitro approaches were used to identify putative lipid receptors for B. cepacia and to explore the nature of the binding interaction. As judged by thin-layer chromatography overlay assays, the best receptors were digalactosylceramide and globotriosylceramide (Gb(3)). Both contain and unsubstituted terminal Gal alpha 1-4Gal sequence. B cepacia also bound moderately to galactosylceramide, gangliotriosylceramide, and gangliotetraosylceramide. Binding to glycolipids was not affected by tetramethylurea, a hydrophobic-bond-breaking adhesin for GB(3). Binding to glycolipids was not affected by tetramethylurea, a hydrophobic-bond-breaking agent. Binding was influenced by the structure of the ceramide, which probably affects the presentation of the agent. Binding was influenced by the structure of the ceramide, which probably affects the presentation of the carbohydrate epitope to the bacteria. Gb(3) was also the major receptor in lipid extracts of human erythrocytes, human buccal epithelial cells and HEp-2 laryngeal epithelial cells. In a receptor-based enzyme-linked immunosorbent assay, binding to Gb(3) within a phospholipid-cholesterol mixture (a membrane-like environment) increased and then approached saturation as a direct function of increasing bacterial concentration. The calculated value of K(a) (3.06 X 10(-8) ml/CFU), the affinity constant, was almost identical to the K(a) calculated earlier for B. cepacia binding to a set of lipid receptors in buccal epithelial cells (1.5 X 10(-8) to 2.0 X 10(-8) ml/CFU). Our findings suggest that within cell membranes, galactose-containing glycolipids, particularly Gb(3) are good candidates for receptors for B. cepacia, particularly for isolates in which cable pili are poorly expressed.
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Affiliation(s)
- F A Sylvester
- Division of Gastroenterology, The Hospital for Sick Children and University of Toronto, Ontario, Canada
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Affiliation(s)
- J E Hearst
- Department of Chemistry, University of California, Berkeley 94720, USA
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Sun L, Jiang RZ, Steinbach S, Holmes A, Campanelli C, Forstner J, Sajjan U, Tan Y, Riley M, Goldstein R. The emergence of a highly transmissible lineage of cbl+ Pseudomonas (Burkholderia) cepacia causing CF centre epidemics in North America and Britain. Nat Med 1995; 1:661-6. [PMID: 7585148 DOI: 10.1038/nm0795-661] [Citation(s) in RCA: 171] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The rapid increase in Pseudomonas (Burkholderia) cepacia infection in cystic fibrosis (CF) patients suggests epidemic transmission, but the degree of transmissibility remains controversial as conflicting conclusions have been drawn from studies at different CF centres. This report provides the first DNA sequence-based documentation of a divergent evolutionary lineage of P. cepacia associated with CF centre epidemics in North America (Toronto) and Europe (Edinburgh). The involved epidemic clone encoded and expressed novel cable (Cbl) pili that bind to CF mucin. The sequence of the cblA pilin subunit gene carried by the epidemic isolates proved to be invariant. Although it remains to be determined how many distinct, highly transmissible lineages exist, our results provide both a DNA sequence and chromosomal fingerprint that can be used to screen for one such particularly infectious, transatlantic clone.
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Affiliation(s)
- L Sun
- Section of Molecular Genetics, Maxwell Finland Laboratory for Infectious Diseases, Boston University School of Medicine, Massachusetts 02118, USA
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44
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Sajjan US, Sun L, Goldstein R, Forstner JF. Cable (cbl) type II pili of cystic fibrosis-associated Burkholderia (Pseudomonas) cepacia: nucleotide sequence of the cblA major subunit pilin gene and novel morphology of the assembled appendage fibers. J Bacteriol 1995; 177:1030-8. [PMID: 7532166 PMCID: PMC176699 DOI: 10.1128/jb.177.4.1030-1038.1995] [Citation(s) in RCA: 126] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Previous studies have shown that appendage pili of Burkholderia cepacia strains isolated from patients with cystic fibrosis (CF) at The Hospital for Sick Children, Toronto, Canada, mediate adherence to mucus glycoproteins and also enhance adherence to epithelial cells. The specific pilin-associated adhesin molecule is a 22-kDa protein. In the present study we purified the major subunit pilin (17 kDa) and immunolocalized it to peritrichously arranged pili. On the basis of their novel morphological appearance as giant intertwined fibers, we refer to them as cable (Cbl) pili. Using an oligonucleotide probe corresponding to regions of the N-terminal amino acid sequence of the pilin subunit, we detected the encoding cblA gene in a chromosomal DNA library. Sequencing revealed this structural gene to be 555 bp in length, encoding a leader sequence of 19 amino acids, a cleavage site between the alanine at position 19 and the valine at position 20, and a mature pilin sequence of 165 amino acids. The calculated molecular mass is 17.3 kDa. Hydrophobic plus apolar amino acids account for 60% of the total residues. The pilin exhibits some similarities in its amino acid sequence to colonization factor antigen I and CS1 fimbriae of Escherichia coli. With the cblA gene used as a probe, hybridization assays of 59 independent isolates, including those from several geographically separated CF centers, plus environmental and clinical (non-CF) strains, gave positive results with all of the 15 CF-associated B. cepacia isolates from Toronto, plus a single strain from one other CF center (Jackson, Mississippi). The cblA gene is the first pilin subunit gene of B. cepacia to be identified.
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Affiliation(s)
- U S Sajjan
- Division of Biochemistry, Hospital for Sick Children, Toronto, Ontario, Canada
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