1
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Han L, Zhang H, Bai X, Jiang B. The peanut root exudate increases the transport and metabolism of nutrients and enhances the plant growth-promoting effects of burkholderia pyrrocinia strain P10. BMC Microbiol 2023; 23:85. [PMID: 36991332 PMCID: PMC10061817 DOI: 10.1186/s12866-023-02818-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 03/10/2023] [Indexed: 03/31/2023] Open
Abstract
BACKGROUND Burkholderia pyrrocinia strain P10 is a plant growth-promoting rhizobacterium (PGPR) that can substantially increase peanut growth. However, the mechanisms and pathways involved in the interaction between B. pyrrocinia P10 and peanut remain unclear. To clarify complex plant-PGPR interactions and the growth-promoting effects of PGPR strains, the B. pyrrocinia P10 transcriptome changes in response to the peanut root exudate (RE) were elucidated and the effects of RE components on biofilm formation and indole-3-acetic acid (IAA) secretion were analyzed. RESULTS During the early interaction phase, the peanut RE enhanced the transport and metabolism of nutrients, including carbohydrates, amino acids, nitrogen, and sulfur. Although the expression of flagellar assembly-related genes was down-regulated, the expression levels of other genes involved in biofilm formation, quorum sensing, and Type II, III, and VI secretion systems were up-regulated, thereby enabling strain P10 to outcompete other microbes to colonize the peanut rhizosphere. The peanut RE also improved the plant growth-promoting effects of strain P10 by activating the expression of genes associated with siderophore biosynthesis, IAA production, and phosphorus solubilization. Additionally, organic acids and amino acids were identified as the dominant components in the peanut RE. Furthermore, strain P10 biofilm formation was induced by malic acid, oxalic acid, and citric acid, whereas IAA secretion was promoted by the alanine, glycine, and proline in the peanut RE. CONCLUSION The peanut RE positively affects B. pyrrocinia P10 growth, while also enhancing colonization and growth-promoting effects during the early interaction period. These findings may help to elucidate the mechanisms underlying complex plant-PGPR interactions, with potential implications for improving the applicability of PGPR strains.
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Affiliation(s)
- Lizhen Han
- College of Life Sciences, Guizhou University, 550025, Guiyang, Guizhou, China.
| | - Hong Zhang
- College of Life Sciences, Guizhou University, 550025, Guiyang, Guizhou, China
| | - Xue Bai
- College of Life Sciences, Guizhou University, 550025, Guiyang, Guizhou, China
| | - Biao Jiang
- College of Life Sciences, Guizhou University, 550025, Guiyang, Guizhou, China
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2
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Bermeo R, Lal K, Ruggeri D, Lanaro D, Mazzotta S, Vasile F, Imberty A, Belvisi L, Varrot A, Bernardi A. Targeting a Multidrug-Resistant Pathogen: First Generation Antagonists of Burkholderia cenocepacia's BC2L-C Lectin. ACS Chem Biol 2022; 17:2899-2910. [PMID: 36174276 PMCID: PMC9594048 DOI: 10.1021/acschembio.2c00532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Multidrug-resistant pathogens such as Burkholderia cenocepacia have become a hazard in the context of healthcare-associated infections, especially for patients admitted with cystic fibrosis or immuno-compromising conditions. Like other opportunistic Gram-negative bacteria, this pathogen establishes virulence and biofilms through lectin-mediated adhesion. In particular, the superlectin BC2L-C is believed to cross-link human epithelial cells to B. cenocepacia during pulmonary infections. We aimed to obtain glycomimetic antagonists able to inhibit the interaction between the N-terminal domain of BC2L-C (BC2L-C-Nt) and its target fucosylated human oligosaccharides. In a previous study, we identified by fragment virtual screening and validated a small set of molecular fragments that bind BC2L-C-Nt in the vicinity of the fucose binding site. Here, we report the rational design and synthesis of bifunctional C- or N-fucosides, generated by connecting these fragments to a fucoside core using a panel of rationally selected linkers. A modular route starting from two key fucoside intermediates was implemented for the synthesis, followed by evaluation of the new compounds as BC2L-C-Nt ligands with a range of techniques (surface plasmon resonance, isothermal titration calorimetry, saturation transfer difference NMR, differential scanning calorimetry, and X-ray crystallography). This study resulted in a hit molecule with an order of magnitude gain over the starting methyl fucoside and in two crystal structures of antagonist/lectin complexes.
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Affiliation(s)
- Rafael Bermeo
- CNRS,
CERMAV, Univ. Grenoble Alpes, Grenoble 38000, France,Dipartimento
di Chimica, Università degli Studi
di Milano, via Golgi 19, Milano 20133, Italy
| | - Kanhaya Lal
- CNRS,
CERMAV, Univ. Grenoble Alpes, Grenoble 38000, France,Dipartimento
di Chimica, Università degli Studi
di Milano, via Golgi 19, Milano 20133, Italy
| | - Davide Ruggeri
- Dipartimento
di Chimica, Università degli Studi
di Milano, via Golgi 19, Milano 20133, Italy
| | - Daniele Lanaro
- Dipartimento
di Chimica, Università degli Studi
di Milano, via Golgi 19, Milano 20133, Italy
| | - Sarah Mazzotta
- Dipartimento
di Chimica, Università degli Studi
di Milano, via Golgi 19, Milano 20133, Italy
| | - Francesca Vasile
- Dipartimento
di Chimica, Università degli Studi
di Milano, via Golgi 19, Milano 20133, Italy
| | - Anne Imberty
- CNRS,
CERMAV, Univ. Grenoble Alpes, Grenoble 38000, France
| | - Laura Belvisi
- Dipartimento
di Chimica, Università degli Studi
di Milano, via Golgi 19, Milano 20133, Italy
| | | | - Anna Bernardi
- Dipartimento
di Chimica, Università degli Studi
di Milano, via Golgi 19, Milano 20133, Italy,
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3
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Production and Purification of Two Bioactive Antimicrobial Peptides Using a Two-Step Approach Involving an Elastin-Like Fusion Tag. Pharmaceuticals (Basel) 2021; 14:ph14100956. [PMID: 34681180 PMCID: PMC8541314 DOI: 10.3390/ph14100956] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 09/17/2021] [Accepted: 09/20/2021] [Indexed: 01/21/2023] Open
Abstract
Antimicrobial resistance is an increasing global threat, demanding new therapeutic biomolecules against multidrug-resistant bacteria. Antimicrobial peptides (AMPs) are promising candidates for a new generation of antibiotics, but their potential application is still in its infancy, mostly due to limitations associated with large-scale production. The use of recombinant DNA technology for the production of AMPs fused with polymer tags presents the advantage of high-yield production and cost-efficient purification processes at high recovery rates. Owing to their unique properties, we explored the use of an elastin-like recombinamer (ELR) as a fusion partner for the production and isolation of two different AMPs (ABP-CM4 and Synoeca-MP), with an interspacing formic acid cleavage site. Recombinant AMP-ELR proteins were overproduced in Escherichia coli and efficiently purified by temperature cycles. The introduction of a formic acid cleavage site allowed the isolation of AMPs, resorting to a two-step methodology involving temperature cycles and a simple size-exclusion purification step. This simple and easy-to-implement purification method was demonstrated to result in high recovery rates of bioactive AMPs. The minimum inhibitory concentration (MIC) of the free AMPs was determined against seven different bacteria of clinical relevance (Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and two Burkholderia cenocepacia strains), in accordance with the EUCAST/CLSI antimicrobial susceptibility testing standards. All the bacterial strains (except for Pseudomonas aeruginosa) were demonstrated to be susceptible to ABP-CM4, including a resistant Burkholderia cenocepacia clinical strain. As for Synoeca-MP, although it did not inhibit the growth of Pseudomonas aeruginosa or Klebsiella pneumoniae, it was demonstrated to be highly active against the remaining bacteria. The present work provides the basis for the development of an efficient and up-scalable biotechnological platform for the production and purification of active AMPs against clinically relevant bacteria.
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4
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Conservation of Resistance-Nodulation-Cell Division Efflux Pump-Mediated Antibiotic Resistance in Burkholderia cepacia Complex and Burkholderia pseudomallei Complex Species. Antimicrob Agents Chemother 2021; 65:e0092021. [PMID: 34181473 DOI: 10.1128/aac.00920-21] [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: 12/20/2022] Open
Abstract
Burkholderia cepacia complex (Bcc) and Burkholderia pseudomallei complex (Bpc) species include pathogens that are typically multidrug resistant. Dominant intrinsic and acquired multidrug resistance mechanisms are efflux mediated by pumps of the resistance-nodulation-cell division (RND) family. From comparative bioinformatic and, in many instances, functional studies, we infer that RND pump-based resistance mechanisms are conserved in Burkholderia. We propose to use these findings as a foundation for adoption of a uniform RND efflux pump nomenclature.
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5
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Scoffone VC, Trespidi G, Barbieri G, Irudal S, Perrin E, Buroni S. Role of RND Efflux Pumps in Drug Resistance of Cystic Fibrosis Pathogens. Antibiotics (Basel) 2021; 10:863. [PMID: 34356783 PMCID: PMC8300704 DOI: 10.3390/antibiotics10070863] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 07/01/2021] [Accepted: 07/13/2021] [Indexed: 01/21/2023] Open
Abstract
Drug resistance represents a great concern among people with cystic fibrosis (CF), due to the recurrent and prolonged antibiotic therapy they should often undergo. Among Multi Drug Resistance (MDR) determinants, Resistance-Nodulation-cell Division (RND) efflux pumps have been reported as the main contributors, due to their ability to extrude a wide variety of molecules out of the bacterial cell. In this review, we summarize the principal RND efflux pump families described in CF pathogens, focusing on the main Gram-negative bacterial species (Pseudomonas aeruginosa, Burkholderia cenocepacia, Achromobacter xylosoxidans, Stenotrophomonas maltophilia) for which a predominant role of RND pumps has been associated to MDR phenotypes.
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Affiliation(s)
- Viola Camilla Scoffone
- Department of Biology and Biotechnology “Lazzaro Spallanzani”, University of Pavia, 27100 Pavia, Italy; (V.C.S.); (G.T.); (G.B.); (S.I.)
| | - Gabriele Trespidi
- Department of Biology and Biotechnology “Lazzaro Spallanzani”, University of Pavia, 27100 Pavia, Italy; (V.C.S.); (G.T.); (G.B.); (S.I.)
| | - Giulia Barbieri
- Department of Biology and Biotechnology “Lazzaro Spallanzani”, University of Pavia, 27100 Pavia, Italy; (V.C.S.); (G.T.); (G.B.); (S.I.)
| | - Samuele Irudal
- Department of Biology and Biotechnology “Lazzaro Spallanzani”, University of Pavia, 27100 Pavia, Italy; (V.C.S.); (G.T.); (G.B.); (S.I.)
| | - Elena Perrin
- Department of Biology, University of Florence, 50019 Sesto Fiorentino, Italy
| | - Silvia Buroni
- Department of Biology and Biotechnology “Lazzaro Spallanzani”, University of Pavia, 27100 Pavia, Italy; (V.C.S.); (G.T.); (G.B.); (S.I.)
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6
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Pimenta AI, Bernardes N, Alves MM, Mil-Homens D, Fialho AM. Burkholderia cenocepacia transcriptome during the early contacts with giant plasma membrane vesicles derived from live bronchial epithelial cells. Sci Rep 2021; 11:5624. [PMID: 33707642 PMCID: PMC7970998 DOI: 10.1038/s41598-021-85222-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 02/22/2021] [Indexed: 01/31/2023] Open
Abstract
Burkholderia cenocepacia is known for its capacity of adherence and interaction with the host, causing severe opportunistic lung infections in cystic fibrosis patients. In this work we produced Giant Plasma Membrane Vesicles (GPMVs) from a bronchial epithelial cell line and validated their use as a cell-like alternative to investigate the steps involved in the adhesion process of B. cenocepacia. RNA-sequencing was performed and the analysis of the B. cenocepacia K56-2 transcriptome after the first contacts with the surface of host cells allowed the recognition of genes implicated in bacterial adaptation and virulence-associated functions. The sensing of host membranes led to a transcriptional shift that caused a cascade of metabolic and physiological adaptations to the host specific environment. Many of the differentially expressed genes encode proteins related with central metabolic pathways, transport systems, cellular processes, and virulence traits. The understanding of the changes in gene expression that occur in the early steps of infection can uncover new proteins implicated in B. cenocepacia-host cell adhesion, against which new blocking agents could be designed to control the progression of the infectious process.
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Affiliation(s)
- Andreia I. Pimenta
- iBB-Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Av. Rovisco Pais 1, 1049-001 Lisbon, Portugal
| | - Nuno Bernardes
- iBB-Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Av. Rovisco Pais 1, 1049-001 Lisbon, Portugal
| | - Marta M. Alves
- grid.9983.b0000 0001 2181 4263CQE Instituto Superior Técnico, Departamento de Engenharia Química, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
| | - Dalila Mil-Homens
- iBB-Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Av. Rovisco Pais 1, 1049-001 Lisbon, Portugal
| | - Arsenio M. Fialho
- iBB-Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Av. Rovisco Pais 1, 1049-001 Lisbon, Portugal ,grid.9983.b0000 0001 2181 4263Department of Bioengineering, Instituto Superior Técnico, University of Lisbon, Lisbon, Portugal
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7
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Shropshire H, Jones RA, Aguilo-Ferretjans MM, Scanlan DJ, Chen Y. Proteomics insights into the Burkholderia cenocepacia phosphorus stress response. Environ Microbiol 2021; 23:5069-5086. [PMID: 33684254 DOI: 10.1111/1462-2920.15451] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 03/02/2021] [Indexed: 11/26/2022]
Abstract
The Burkholderia cepacia complex is a group of Burkholderia species that are opportunistic pathogens causing high mortality rates in patients with cystic fibrosis. An environmental stress often encountered by these soil-dwelling and pathogenic bacteria is phosphorus limitation, an essential element for cellular processes. Here, we describe cellular and extracellular proteins differentially regulated between phosphate-deplete (0 mM, no added phosphate) and phosphate-replete (1 mM) growth conditions using a comparative proteomics (LC-MS/MS) approach. We observed a total of 128 and 65 unique proteins were downregulated and upregulated respectively, in the B. cenocepacia proteome. Of those downregulated proteins, many have functions in amino acid transport/metabolism. We have identified 24 upregulated proteins that are directly/indirectly involved in inorganic phosphate or organic phosphorus acquisition. Also, proteins involved in virulence and antimicrobial resistance were differentially regulated, suggesting B. cenocepacia experiences a dramatic shift in metabolism under these stress conditions. Overall, this study provides a baseline for further research into the biology of Burkholderia in response to phosphorus stress.
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Affiliation(s)
- Holly Shropshire
- BBSRC Midlands Integrative Biosciences Training Partnership, University of Warwick, Coventry, CV4 7AL, UK.,School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | - Rebekah A Jones
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | | | - David J Scanlan
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | - Yin Chen
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
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8
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Hassan AA, Dos Santos SC, Cooper VS, Sá-Correia I. Comparative Evolutionary Patterns of Burkholderia cenocepacia and B. multivorans During Chronic Co-infection of a Cystic Fibrosis Patient Lung. Front Microbiol 2020; 11:574626. [PMID: 33101250 PMCID: PMC7545829 DOI: 10.3389/fmicb.2020.574626] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Accepted: 08/31/2020] [Indexed: 12/26/2022] Open
Abstract
During chronic respiratory infections of cystic fibrosis (CF) patients, bacteria adaptively evolve in response to the nutritional and immune environment as well as influence other infecting microbes. The present study was designed to gain insights into the genetic mechanisms underlying adaptation and diversification by the two most prevalent pathogenic species of the Burkholderia cepacia complex (Bcc), B. cenocepacia and B. multivorans. Herein, we study the evolution of both of these species during coinfection of a CF patient for 4.4 years using genome sequences of 9 B. multivorans and 11 B. cenocepacia. This co-infection spanned at least 3 years following initial infection by B. multivorans and ultimately ended in the patient's death by cepacia syndrome. Both species acquired several mutations with accumulation rates of 2.08 (B. cenocepacia) and 2.27 (B. multivorans) SNPs/year. Many of the mutated genes are associated with oxidative stress response, transition metal metabolism, defense mechanisms against antibiotics, and other metabolic alterations consistent with the idea that positive selection might be driven by the action of the host immune system, antibiotic therapy and low oxygen and iron concentrations. Two orthologous genes shared by B. cenocepacia and B. multivorans were found to be under strong selection and accumulated mutations associated with lineage diversification. One gene encodes a nucleotide sugar dehydratase involved in lipopolysaccharide O-antigen (OAg) biosynthesis (wbiI). The other gene encodes a putative two-component regulatory sensor kinase protein required to sense and adapt to oxidative- and heavy metal- inducing stresses. This study contributes to understanding of shared and species-specific evolutionary patterns of B. cenocepacia and B. multivorans evolving in the same CF lung environment.
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Affiliation(s)
- A Amir Hassan
- iBB - Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal.,Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Sandra C Dos Santos
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Vaughn S Cooper
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - Isabel Sá-Correia
- iBB - Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal.,Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
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9
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Zhou J, Ren H, Hu M, Zhou J, Li B, Kong N, Zhang Q, Jin Y, Liang L, Yue J. Characterization of Burkholderia cepacia Complex Core Genome and the Underlying Recombination and Positive Selection. Front Genet 2020; 11:506. [PMID: 32528528 PMCID: PMC7253759 DOI: 10.3389/fgene.2020.00506] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 04/24/2020] [Indexed: 11/13/2022] Open
Abstract
Recombination and positive selection are two key factors that play a vital role in pathogenic microorganisms’ population adaptation and diversification. The Burkholderia cepacia complex (Bcc) represents bacterial species with high similarity, which can cause severe infections among cases suffering from the chronic granulomatous disorder and cystic fibrosis (CF). At present, no genome-wide study has been carried out focusing on investigating the core genome of Bcc associated with the two evolutionary forces. The general characteristics of the core genome of Bcc species remain scarce as well. In this study, we explored the core orthologous genes of 116 Bcc strains using comparative genomic analysis and studied the two adaptive evolutionary forces: recombination and positive selection. We estimated 1005 orthogroups consisting entirely of single copy genes. These single copy orthologous genes in some Cluster of Orthologous Groups (COG) categories showed significant differences in the comparison of several evolutionary properties, and the encoding proteins were relatively simple and compact. Our findings showed that 5.8% of the core orthologous genes strongly supported recombination; in the meantime, 1.1% supported positive selection. We found that genes involved in protein synthesis as well as material transport and metabolism are favored by selection pressure. More importantly, homologous recombination contributed more genetic variation to a large number of genes and largely maintained the genetic cohesion in Bcc. This high level of recombination between Bcc species blurs their taxonomic boundaries, which leads Bcc species to be difficult or impossible to distinguish phenotypically and genotypically.
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Affiliation(s)
- Jianglin Zhou
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, Beijing, China
| | - Hongguang Ren
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, Beijing, China
| | - Mingda Hu
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, Beijing, China
| | - Jing Zhou
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, Beijing, China
| | - Beiping Li
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, Beijing, China
| | - Na Kong
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, Beijing, China.,Institutes of Physical Science and Information Technology, Anhui University, Hefei, China
| | - Qi Zhang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, Beijing, China
| | - Yuan Jin
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, Beijing, China
| | - Long Liang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, Beijing, China
| | - Junjie Yue
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, Beijing, China
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10
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Burkholderia cepacia Complex Bacteria: a Feared Contamination Risk in Water-Based Pharmaceutical Products. Clin Microbiol Rev 2020; 33:33/3/e00139-19. [PMID: 32295766 DOI: 10.1128/cmr.00139-19] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Burkholderia cepacia (formerly Pseudomonas cepacia) was once thought to be a single bacterial species but has expanded to the Burkholderia cepacia complex (Bcc), comprising 24 closely related opportunistic pathogenic species. These bacteria have a widespread environmental distribution, an extraordinary metabolic versatility, a complex genome with three chromosomes, and a high capacity for rapid mutation and adaptation. Additionally, they present an inherent resistance to antibiotics and antiseptics, as well as the abilities to survive under nutrient-limited conditions and to metabolize the organic matter present in oligotrophic aquatic environments, even using certain antimicrobials as carbon sources. These traits constitute the reason that Bcc bacteria are considered feared contaminants of aqueous pharmaceutical and personal care products and the frequent reason behind nonsterile product recalls. Contamination with Bcc has caused numerous nosocomial outbreaks in health care facilities, presenting a health threat, particularly for patients with cystic fibrosis and chronic granulomatous disease and for immunocompromised individuals. This review addresses the role of Bcc bacteria as a potential public health problem, the mechanisms behind their success as contaminants of pharmaceutical products, particularly in the presence of biocides, the difficulties encountered in their detection, and the preventive measures applied during manufacturing processes to control contamination with these objectionable microorganisms. A summary of Bcc-related outbreaks in different clinical settings, due to contamination of diverse types of pharmaceutical products, is provided.
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11
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Sánchez-Rodríguez R, González GM, Becerril-García MA, Treviño-Rangel RDJ, Marcos-Vilchis A, González-Pedrajo B, Valvano MA, Andrade A. The BPtpA protein from Burkholderia cenocepacia belongs to a new subclass of low molecular weight protein tyrosine phosphatases. Arch Biochem Biophys 2020; 681:108277. [PMID: 31978399 DOI: 10.1016/j.abb.2020.108277] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 01/15/2020] [Accepted: 01/17/2020] [Indexed: 11/24/2022]
Abstract
Low molecular weight protein tyrosine phosphatases (LMW-PTP) are ubiquitous enzymes found across a spectrum of genera from prokaryotes to higher eukaryotes. LMW-PTP belong to the Cys-based PTP class II protein family. Here, we show that LMW-PTP can be categorized into two different groups, referred as class II subdivision I (class II.I) and subdivision II (class II.II). Using BPtpA from the opportunistic pathogen Burkholderia cenocepacia, as a representative member of the LMW-PTP class II.I, we demonstrated that four conserved residues (W47, H48, D80, and F81) are required for enzyme function. Guided by an in silico model of BPtpA, we show that the conserved residues at α3-helix (D80 and F81) contribute to protein stability, while the other conserved residues in the W-loop (W47 and H48) likely play a role in substrate recognition. Overall, our results provide new information on LMW-PTP protein family and establish B. cenocepacia as a suitable model to investigate how substrates are recognized and sorted by these proteins.
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Affiliation(s)
- Rebeca Sánchez-Rodríguez
- Universidad Autónoma de Nuevo León, Facultad de Medicina, Departamento de Microbiología. Monterrey, Nuevo León, 64460, Mexico
| | - Gloria M González
- Universidad Autónoma de Nuevo León, Facultad de Medicina, Departamento de Microbiología. Monterrey, Nuevo León, 64460, Mexico
| | - Miguel A Becerril-García
- Universidad Autónoma de Nuevo León, Facultad de Medicina, Departamento de Microbiología. Monterrey, Nuevo León, 64460, Mexico
| | - Rogelio de J Treviño-Rangel
- Universidad Autónoma de Nuevo León, Facultad de Medicina, Departamento de Microbiología. Monterrey, Nuevo León, 64460, Mexico
| | - Arely Marcos-Vilchis
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, 70-243, Mexico
| | - Bertha González-Pedrajo
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, 70-243, Mexico
| | - Miguel A Valvano
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast, BT9 7BL, United Kingdom
| | - Angel Andrade
- Universidad Autónoma de Nuevo León, Facultad de Medicina, Departamento de Microbiología. Monterrey, Nuevo León, 64460, Mexico.
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12
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Hassan AA, Vitorino MV, Robalo T, Rodrigues MS, Sá-Correia I. Variation of Burkholderia cenocepacia cell wall morphology and mechanical properties during cystic fibrosis lung infection, assessed by atomic force microscopy. Sci Rep 2019; 9:16118. [PMID: 31695169 PMCID: PMC6834607 DOI: 10.1038/s41598-019-52604-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 10/21/2019] [Indexed: 12/13/2022] Open
Abstract
The influence that Burkholderia cenocepacia adaptive evolution during long-term infection in cystic fibrosis (CF) patients has on cell wall morphology and mechanical properties is poorly understood despite their crucial role in cell physiology, persistent infection and pathogenesis. Cell wall morphology and physical properties of three B. cenocepacia isolates collected from a CF patient over a period of 3.5 years were compared using atomic force microscopy (AFM). These serial clonal variants include the first isolate retrieved from the patient and two late isolates obtained after three years of infection and before the patient’s death with cepacia syndrome. A consistent and progressive decrease of cell height and a cell shape evolution during infection, from the typical rods to morphology closer to cocci, were observed. The images of cells grown in biofilms showed an identical cell size reduction pattern. Additionally, the apparent elasticity modulus significantly decreases from the early isolate to the last clonal variant retrieved from the patient but the intermediary highly antibiotic resistant clonal isolate showed the highest elasticity values. Concerning the adhesion of bacteria surface to the AFM tip, the first isolate was found to adhere better than the late isolates whose lipopolysaccharide (LPS) structure loss the O-antigen (OAg) during CF infection. The OAg is known to influence Gram-negative bacteria adhesion and be an important factor in B. cenocepacia adaptation to chronic infection. Results reinforce the concept of the occurrence of phenotypic heterogeneity and adaptive evolution, also at the level of cell size, form, envelope topography and physical properties during long-term infection.
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Affiliation(s)
- A Amir Hassan
- iBB - Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, 1049-001, Portugal.,Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, 1049-001, Portugal
| | - Miguel V Vitorino
- BioISI - Biosystems and Integrative Sciences Institute, Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisboa, Portugal.,Departamento de Física, Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisboa, Portugal
| | - Tiago Robalo
- BioISI - Biosystems and Integrative Sciences Institute, Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisboa, Portugal
| | - Mário S Rodrigues
- BioISI - Biosystems and Integrative Sciences Institute, Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisboa, Portugal. .,Departamento de Física, Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisboa, Portugal.
| | - Isabel Sá-Correia
- iBB - Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, 1049-001, Portugal. .,Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, 1049-001, Portugal.
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13
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Treffon J, Block D, Moche M, Reiss S, Fuchs S, Engelmann S, Becher D, Langhanki L, Mellmann A, Peters G, Kahl BC. Adaptation of Staphylococcus aureus to Airway Environments in Patients With Cystic Fibrosis by Upregulation of Superoxide Dismutase M and Iron-Scavenging Proteins. J Infect Dis 2019; 217:1453-1461. [PMID: 29325044 DOI: 10.1093/infdis/jiy012] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 01/05/2018] [Indexed: 01/24/2023] Open
Abstract
Adaptation of S. aureus to the hostile environment of CF airways resulted in changed abundance of proteins involved in energy metabolism, cellular processes, transport and binding, but most importantly in an iron-scavenging phenotype and increased activity of superoxide dismutase M.
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Affiliation(s)
| | | | - Martin Moche
- Institute of Microbiology, Ernst-Moritz-Arndt-University, Greifswald
| | - Swantje Reiss
- Institute of Microbiology, Ernst-Moritz-Arndt-University, Greifswald
| | - Stephan Fuchs
- Institute of Microbiology, Ernst-Moritz-Arndt-University, Greifswald.,Department of Infectious Diseases, Robert Koch Institute, Wernigerode
| | - Susanne Engelmann
- Institute of Microbiology, Ernst-Moritz-Arndt-University, Greifswald.,Institute of Microbiology, Technical University Braunschweig, Braunschweig, Germany.,Microbial Proteomics, Helmholtz Center for Infection Research, Braunschweig, Germany
| | - Dörte Becher
- Institute of Microbiology, Ernst-Moritz-Arndt-University, Greifswald
| | - Lars Langhanki
- Institute of Hygiene, University Hospital Münster, Münster
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14
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Diaz Caballero J, Clark ST, Wang PW, Donaldson SL, Coburn B, Tullis DE, Yau YCW, Waters VJ, Hwang DM, Guttman DS. A genome-wide association analysis reveals a potential role for recombination in the evolution of antimicrobial resistance in Burkholderia multivorans. PLoS Pathog 2018; 14:e1007453. [PMID: 30532201 PMCID: PMC6300292 DOI: 10.1371/journal.ppat.1007453] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 12/19/2018] [Accepted: 11/02/2018] [Indexed: 01/05/2023] Open
Abstract
Cystic fibrosis (CF) lung infections caused by members of the Burkholderia cepacia complex, such as Burkholderia multivorans, are associated with high rates of mortality and morbidity. We performed a population genomics study of 111 B. multivorans sputum isolates from one CF patient through three stages of infection including an early incident isolate, deep sampling of a one-year period of chronic infection occurring weeks before a lung transplant, and deep sampling of a post-transplant infection. We reconstructed the evolutionary history of the population and used a lineage-controlled genome-wide association study (GWAS) approach to identify genetic variants associated with antibiotic resistance. We found the incident isolate was basally related to the rest of the strains and more susceptible to antibiotics from three classes (β-lactams, aminoglycosides, quinolones). The chronic infection isolates diversified into multiple, distinct genetic lineages and showed reduced antimicrobial susceptibility to the same antibiotics. The post-transplant reinfection isolates derived from the same source as the incident isolate and were genetically distinct from the chronic isolates. They also had a level of susceptibility in between that of the incident and chronic isolates. We identified numerous examples of potential parallel pathoadaptation, in which multiple mutations were found in the same locus or even codon. The set of parallel pathoadaptive loci was enriched for functions associated with virulence and resistance. Our GWAS analysis identified statistical associations between a polymorphism in the ampD locus with resistance to β-lactams, and polymorphisms in an araC transcriptional regulator and an outer membrane porin with resistance to both aminoglycosides and quinolones. Additionally, these three loci were independently mutated four, three and two times, respectively, providing further support for parallel pathoadaptation. Finally, we identified a minimum of 14 recombination events, and observed that loci carrying putative parallel pathoadaptations and polymorphisms statistically associated with β-lactam resistance were over-represented in these recombinogenic regions. Cystic fibrosis (CF) is the most common lethal genetic disorder affecting individuals of European descent. Most CF patients die at a young age due to chronic lung infections. Among the organisms involved in these infections are bacteria from the Burkholderia cepacia complex (BCC), which are strongly associated with poor clinical prognosis. This study examines how the most prevalent BCC species among CF patients, B. multivorans, evolves within a single CF patient by studying the first B. multivorans isolate recovered from the patient, one hundred isolates recovered over a one year period during the chronic infection phase, and an additional ten isolates recovered after the reinfection of the transplanted lungs. We found that B. multivorans diversify phenotypically and genetically within the CF lung over the course of the infection, and evolves into a complex population during the chronic infection phase. We found that isolates collected from the post-transplant reinfection were more closely related to descendants of the original isolate rather than those recovered in the chronic infection. We identify genetic variants statistically associated with resistance to the antibiotics, and showed that some of these variants were found in regions that show patterns of recombination (genetic exchange) between strains. We also found that genes which were mutated multiple times during overall infection were more likely to be found in regions showing signals consistent with recombination. The presence of multiple independent mutations in a gene is a very strong signal that the gene helps bacteria adapt to their environment. Overall, this study provides insight into how pathogens adapt to the host during long-term infections, specific genes associated with antibiotic resistance, and the origin of new and recurrent infections.
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Affiliation(s)
- Julio Diaz Caballero
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Shawn T. Clark
- Latner Thoracic Surgery Laboratories, University Health Network, University of Toronto, Toronto, Ontario, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Pauline W. Wang
- Centre for the Analysis of Genome Evolution and Function, University of Toronto, Toronto, Ontario, Canada
| | - Sylva L. Donaldson
- Centre for the Analysis of Genome Evolution and Function, University of Toronto, Toronto, Ontario, Canada
| | - Bryan Coburn
- Division of Infectious Diseases, Department of Medicine, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - D. Elizabeth Tullis
- Adult Cystic Fibrosis Clinic, St. Michael's Hospital, Toronto, Ontario, Canada
| | - Yvonne C. W. Yau
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
- Department of Pediatric Laboratory Medicine, Division of Microbiology, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Valerie J. Waters
- Department of Pediatrics, Division of Infectious Diseases, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - David M. Hwang
- Latner Thoracic Surgery Laboratories, University Health Network, University of Toronto, Toronto, Ontario, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
- Department of Pathology, University Health Network, Toronto, Ontario, Canada
| | - David S. Guttman
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
- Centre for the Analysis of Genome Evolution and Function, University of Toronto, Toronto, Ontario, Canada
- * E-mail:
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15
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Cullen L, O'Connor A, McCormack S, Owens RA, Holt GS, Collins C, Callaghan M, Doyle S, Smith D, Schaffer K, Fitzpatrick DA, McClean S. The involvement of the low-oxygen-activated locus of Burkholderia cenocepacia in adaptation during cystic fibrosis infection. Sci Rep 2018; 8:13386. [PMID: 30190507 PMCID: PMC6127331 DOI: 10.1038/s41598-018-31556-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 08/20/2018] [Indexed: 12/30/2022] Open
Abstract
Chronic infection with opportunistic pathogens including Burkholderia cepacia complex (Bcc) is a hallmark of cystic fibrosis (CF). We investigated the adaptive mechanisms facilitating chronic lung infection in sequential Bcc isolates from two siblings with CF (P1 and P2), one of whom also experienced intermittent blood-stream infections (P2). We previously showed increased lung cell attachment with colonisation time in both P1 and P2. WGS analysis confirmed that the isolates are closely related. Twelve genes showed three or more mutations, suggesting these were genes under selection. Single nucleotide polymorphisms (SNVs) in 45 regulatory genes were also observed. Proteomic analysis showed that the abundance of 149 proteins increased over 61-months in sputum isolates, and both time- and source-related alterations in protein abundance between the second patient’s isolates. A consistent time-dependent increase in abundance of 19 proteins encoded by a low-oxygen-activated (lxa) locus was observed in both sets of isolates. Attachment was dramatically reduced in a B. cenocepacia K56-2Δlxa-locus deletion mutant, further indicating that it encodes protein(s) involved in host-cell attachment. Time-related changes in virulence in Galleria mellonella or motility were not observed. We conclude that the lxa-locus, associated with anoxic persistence in vitro, plays a role in host-cell attachment and adaptation to chronic colonization in the hypoxic niche of the CF lung.
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Affiliation(s)
- Louise Cullen
- Centre of Microbial Host Interactions, Institute of Technology Tallaght, Dublin, 24, Ireland
| | - Andrew O'Connor
- Centre of Microbial Host Interactions, Institute of Technology Tallaght, Dublin, 24, Ireland.,School of Biomolecular and Biomedical Sciences, University College Dublin, Belfield, Dublin, 4, Ireland
| | - Sarah McCormack
- School of Biomolecular and Biomedical Sciences, University College Dublin, Belfield, Dublin, 4, Ireland
| | - Rebecca A Owens
- Department of Biology, Maynooth University, Co. Kildare, Ireland
| | - Giles S Holt
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, England
| | - Cassandra Collins
- Centre of Microbial Host Interactions, Institute of Technology Tallaght, Dublin, 24, Ireland
| | - Máire Callaghan
- Centre of Microbial Host Interactions, Institute of Technology Tallaght, Dublin, 24, Ireland
| | - Sean Doyle
- Department of Biology, Maynooth University, Co. Kildare, Ireland
| | - Darren Smith
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, England
| | - Kirsten Schaffer
- Department of Microbiology, St. Vincent's University Hospital, Elm Park, Dublin, Ireland
| | | | - Siobhán McClean
- Centre of Microbial Host Interactions, Institute of Technology Tallaght, Dublin, 24, Ireland. .,School of Biomolecular and Biomedical Sciences, University College Dublin, Belfield, Dublin, 4, Ireland.
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16
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Butt AT, Thomas MS. Iron Acquisition Mechanisms and Their Role in the Virulence of Burkholderia Species. Front Cell Infect Microbiol 2017; 7:460. [PMID: 29164069 PMCID: PMC5681537 DOI: 10.3389/fcimb.2017.00460] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 10/18/2017] [Indexed: 11/19/2022] Open
Abstract
Burkholderia is a genus within the β-Proteobacteriaceae that contains at least 90 validly named species which can be found in a diverse range of environments. A number of pathogenic species occur within the genus. These include Burkholderia cenocepacia and Burkholderia multivorans, opportunistic pathogens that can infect the lungs of patients with cystic fibrosis, and are members of the Burkholderia cepacia complex (Bcc). Burkholderia pseudomallei is also an opportunistic pathogen, but in contrast to Bcc species it causes the tropical human disease melioidosis, while its close relative Burkholderia mallei is the causative agent of glanders in horses. For these pathogens to survive within a host and cause disease they must be able to acquire iron. This chemical element is essential for nearly all living organisms due to its important role in many enzymes and metabolic processes. In the mammalian host, the amount of accessible free iron is negligible due to the low solubility of the metal ion in its higher oxidation state and the tight binding of this element by host proteins such as ferritin and lactoferrin. As with other pathogenic bacteria, Burkholderia species have evolved an array of iron acquisition mechanisms with which to capture iron from the host environment. These mechanisms include the production and utilization of siderophores and the possession of a haem uptake system. Here, we summarize the known mechanisms of iron acquisition in pathogenic Burkholderia species and discuss the evidence for their importance in the context of virulence and the establishment of infection in the host. We have also carried out an extensive bioinformatic analysis to identify which siderophores are produced by each Burkholderia species that is pathogenic to humans.
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Affiliation(s)
- Aaron T Butt
- Department of Infection, Immunity and Cardiovascular Disease, Faculty of Medicine, Dentistry and Health, University of Sheffield, Sheffield, United Kingdom
| | - Mark S Thomas
- Department of Infection, Immunity and Cardiovascular Disease, Faculty of Medicine, Dentistry and Health, University of Sheffield, Sheffield, United Kingdom
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17
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Pradenas GA, Myers JN, Torres AG. Characterization of the Burkholderia cenocepacia TonB Mutant as a Potential Live Attenuated Vaccine. Vaccines (Basel) 2017; 5:vaccines5040033. [PMID: 28956836 PMCID: PMC5748600 DOI: 10.3390/vaccines5040033] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2017] [Revised: 09/19/2017] [Accepted: 09/26/2017] [Indexed: 12/22/2022] Open
Abstract
Burkholderia cenocepacia is an opportunistic pathogen prevalent in cystic fibrosis patients, which is particularly difficult to treat, causing chronic and eventually fatal infections. The lack of effective treatment options makes evident the need to develop alternative therapeutic or prophylactic approaches. Vaccines, and live attenuated vaccines, are an unexplored avenue to treat B. cenocepacia infections. Here we constructed and characterized a B. cenocepacia tonB mutant strain, which was unable to actively transport iron, to test whether this single gene deletion mutant (strain renamed GAP001) protected against an acute respiratory B. cenocepacia lethal infection. Here we show that the mutant strain GAP001 is attenuated, and effective at protecting against B. cenocepacia challenge. Intranasal administration of GAP001 to BALB/c mice resulted in almost complete survival with high degree of bacterial clearance.
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Affiliation(s)
- Gonzalo A Pradenas
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA.
| | - Julia N Myers
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA.
| | - Alfredo G Torres
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA.
- Sealy Center for Vaccine Development, University of Texas Medical Branch, Galveston, TX 77555, USA.
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18
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Scoffone VC, Chiarelli LR, Trespidi G, Mentasti M, Riccardi G, Buroni S. Burkholderia cenocepacia Infections in Cystic Fibrosis Patients: Drug Resistance and Therapeutic Approaches. Front Microbiol 2017; 8:1592. [PMID: 28878751 PMCID: PMC5572248 DOI: 10.3389/fmicb.2017.01592] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Accepted: 08/04/2017] [Indexed: 12/29/2022] Open
Abstract
Burkholderia cenocepacia is an opportunistic pathogen particularly dangerous for cystic fibrosis (CF) patients. It can cause a severe decline in CF lung function possibly developing into a life-threatening systemic infection known as cepacia syndrome. Antibiotic resistance and presence of numerous virulence determinants in the genome make B. cenocepacia extremely difficult to treat. Better understanding of its resistance profiles and mechanisms is crucial to improve management of these infections. Here, we present the clinical distribution of B. cenocepacia described in the last 6 years and methods for identification and classification of epidemic strains. We also detail new antibiotics, clinical trials, and alternative approaches reported in the literature in the last 5 years to tackle B. cenocepacia resistance issue. All together these findings point out the urgent need of new and alternative therapies to improve CF patients’ life expectancy.
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Affiliation(s)
- Viola C Scoffone
- Department of Biology and Biotechnology, University of PaviaPavia, Italy
| | | | - Gabriele Trespidi
- Department of Biology and Biotechnology, University of PaviaPavia, Italy
| | - Massimo Mentasti
- Respiratory and Vaccine Preventable Bacteria Reference Unit, Public Health EnglandLondon, United Kingdom.,Department of Microbiology, Royal Cornwall HospitalTruro, United Kingdom
| | - Giovanna Riccardi
- Department of Biology and Biotechnology, University of PaviaPavia, Italy
| | - Silvia Buroni
- Department of Biology and Biotechnology, University of PaviaPavia, Italy
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19
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Liu Y, Lardi M, Pedrioli A, Eberl L, Pessi G. NtrC-dependent control of exopolysaccharide synthesis and motility in Burkholderia cenocepacia H111. PLoS One 2017; 12:e0180362. [PMID: 28662146 PMCID: PMC5491218 DOI: 10.1371/journal.pone.0180362] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 06/14/2017] [Indexed: 11/18/2022] Open
Abstract
Burkholderia cenocepacia is a versatile opportunistic pathogen that survives in a wide variety of environments, which can be limited in nutrients such as nitrogen. We have previously shown that the sigma factor σ54 is involved in the control of nitrogen assimilation and virulence in B. cenocepacia H111. In this work, we investigated the role of the σ54 enhancer binding protein NtrC in response to nitrogen limitation and in the pathogenicity of H111. Of 95 alternative nitrogen sources tested the ntrC showed defects in the utilisation of nitrate, urea, L-citrulline, acetamide, DL-lactamide, allantoin and parabanic acid. RNA-Seq and phenotypic analyses of an ntrC mutant strain showed that NtrC positively regulates two important phenotypic traits: exopolysaccharide (EPS) production and motility. However, the ntrC mutant was not attenuated in C. elegans virulence.
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Affiliation(s)
- Yilei Liu
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Martina Lardi
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Alessandro Pedrioli
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Leo Eberl
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
- * E-mail: (LE); (GP)
| | - Gabriella Pessi
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
- * E-mail: (LE); (GP)
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20
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Hassan AA, Maldonado RF, Dos Santos SC, Di Lorenzo F, Silipo A, Coutinho CP, Cooper VS, Molinaro A, Valvano MA, Sá-Correia I. Structure of O-Antigen and Hybrid Biosynthetic Locus in Burkholderia cenocepacia Clonal Variants Recovered from a Cystic Fibrosis Patient. Front Microbiol 2017. [PMID: 28642745 PMCID: PMC5462993 DOI: 10.3389/fmicb.2017.01027] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Burkholderia cenocepacia is an opportunistic pathogen associated with chronic lung infections and increased risk of death in patients with cystic fibrosis (CF). In this work, we investigated the lipopolysaccharide (LPS) of clinical variants of B. cenocepacia that were collected from a CF patient over a period of 3.5 years, from the onset of infection until death by necrotizing pneumonia (cepacia syndrome). We report the chemical structure of the LPS molecule of various sequential isolates and the identification of a novel hybrid O-antigen (OAg) biosynthetic cluster. The OAg repeating unit of the LPS from IST439, the initial isolate, is a [→2)-β-D-Ribf-(1→4)-α-D-GalpNAc-(1→] disaccharide, which was not previously described in B. cenocepacia. The IST439 OAg biosynthetic gene cluster contains 7 of 23 genes that are closely homologous to genes found in B. multivorans, another member of the Burkholderia cepacia complex. None of the subsequent isolates expressed OAg. Genomic sequencing of these isolates enabled the identification of mutations within the OAg cluster, but none of these mutations could be associated with the loss of OAg. This study provides support to the notion that OAg LPS modifications are an important factor in the adaptation of B. cenocepacia to chronic infection and that the heterogeneity of OAgs relates to variation within the OAg gene cluster, indicating that the gene cluster might have been assembled through multiple horizontal transmission events.
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Affiliation(s)
- A A Hassan
- Department of Bioengineering, Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de LisboaLisboa, Portugal
| | - Rita F Maldonado
- Department of Bioengineering, Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de LisboaLisboa, Portugal
| | - Sandra C Dos Santos
- Department of Bioengineering, Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de LisboaLisboa, Portugal
| | - Flaviana Di Lorenzo
- Department of Chemical Sciences, University of Napoli Federico II Complesso Universitário Monte SantangeloNapoli, Italy
| | - Alba Silipo
- Department of Chemical Sciences, University of Napoli Federico II Complesso Universitário Monte SantangeloNapoli, Italy
| | - Carla P Coutinho
- Department of Bioengineering, Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de LisboaLisboa, Portugal
| | - Vaughn S Cooper
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, PittsburghPA, United States
| | - Antonio Molinaro
- Department of Chemical Sciences, University of Napoli Federico II Complesso Universitário Monte SantangeloNapoli, Italy
| | - Miguel A Valvano
- The Wellcome-Wolfson Institute for Experimental Medicine, Queen's University BelfastBelfast, United Kingdom
| | - Isabel Sá-Correia
- Department of Bioengineering, Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de LisboaLisboa, Portugal
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21
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Viberg LT, Sarovich DS, Kidd TJ, Geake JB, Bell SC, Currie BJ, Price EP. Within-Host Evolution of Burkholderia pseudomallei during Chronic Infection of Seven Australasian Cystic Fibrosis Patients. mBio 2017; 8:e00356-17. [PMID: 28400528 PMCID: PMC5388805 DOI: 10.1128/mbio.00356-17] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 03/15/2017] [Indexed: 12/14/2022] Open
Abstract
Cystic fibrosis (CF) is a genetic disorder characterized by progressive lung function decline. CF patients are at an increased risk of respiratory infections, including those by the environmental bacterium Burkholderia pseudomallei, the causative agent of melioidosis. Here, we compared the genomes of B. pseudomallei isolates collected between ~4 and 55 months apart from seven chronically infected CF patients. Overall, the B. pseudomallei strains showed evolutionary patterns similar to those of other chronic infections, including emergence of antibiotic resistance, genome reduction, and deleterious mutations in genes involved in virulence, metabolism, environmental survival, and cell wall components. We documented the first reported B. pseudomallei hypermutators, which were likely caused by defective MutS. Further, our study identified both known and novel molecular mechanisms conferring resistance to three of the five clinically important antibiotics for melioidosis treatment. Our report highlights the exquisite adaptability of microorganisms to long-term persistence in their environment and the ongoing challenges of antibiotic treatment in eradicating pathogens in the CF lung. Convergent evolution with other CF pathogens hints at a degree of predictability in bacterial evolution in the CF lung and potential targeted eradication of chronic CF infections in the future.IMPORTANCEBurkholderia pseudomallei, the causative agent of melioidosis, is an environmental opportunistic bacterium that typically infects immunocompromised people and those with certain risk factors such as cystic fibrosis (CF). Patients with CF tend to develop chronic melioidosis infections, for reasons that are not well understood. This report is the first to describe B. pseudomallei evolution within the CF lung during chronic infection. We show that the pathways by which B. pseudomallei adapts to the CF lung are similar to those seen in better-studied CF pathogens such as Pseudomonas aeruginosa, Staphylococcus aureus, and Burkholderia cepacia complex species. Adaptations include the accumulation of antibiotic resistance, loss of nonessential genes, metabolic alterations, and virulence factor attenuation. Known and novel mechanisms of resistance to three of the five antibiotics used in melioidosis treatment were identified. Similar pathways of evolution in CF pathogens, including B. pseudomallei, provide exciting avenues for more-targeted treatment of chronic, recalcitrant infections.
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Affiliation(s)
- Linda T Viberg
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory, Australia
| | - Derek S Sarovich
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory, Australia
- Centre for Animal Health Innovation, Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Sippy Downs, Queensland, Australia
| | - Timothy J Kidd
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
- Centre for Experimental Medicine, Queen's University Belfast, Belfast, Northern Ireland
- Child Health Research Centre, The University of Queensland, Brisbane, Queensland, Australia
| | - James B Geake
- Department of Respiratory Medicine, The Lyell McEwin Hospital, Elizabeth Vale, South Australia, Australia
| | - Scott C Bell
- QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
- Department of Thoracic Medicine, The Prince Charles Hospital, Chermside, Queensland, Australia
| | - Bart J Currie
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory, Australia
- Department of Infectious Diseases and Northern Territory Medical Program, Royal Darwin Hospital, Darwin, Northern Territory, Australia
| | - Erin P Price
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory, Australia
- Centre for Animal Health Innovation, Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Sippy Downs, Queensland, Australia
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22
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Guo FB, Xiong L, Zhang KY, Dong C, Zhang FZ, Woo PCY. Identification and analysis of genomic islands in Burkholderia cenocepacia AU 1054 with emphasis on pathogenicity islands. BMC Microbiol 2017; 17:73. [PMID: 28347342 PMCID: PMC5369199 DOI: 10.1186/s12866-017-0986-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 03/18/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Genomic islands (GIs) are genomic regions that reveal evidence of horizontal DNA transfer. They can code for many functions and may augment a bacterium's adaptation to its host or environment. GIs have been identified in strain J2315 of Burkholderia cenocepacia, whereas in strain AU 1054 there has been no published works on such regions according to our text mining and keyword search in Medline. RESULTS In this study, we identified 21 GIs in AU 1054 by combining two computational tools. Feature analyses suggested that the predictions are highly reliable and hence illustrated the advantage of joint predictions by two independent methods. Based on putative virulence factors, four GIs were further identified as pathogenicity islands (PAIs). Through experiments of gene deletion mutants in live bacteria, two putative PAIs were confirmed, and the virulence factors involved were identified as lipA and copR. The importance of the genes lipA (from PAI 1) and copR (from PAI 2) for bacterial invasion and replication indicates that they are required for the invasive properties of B. cenocepacia and may function as virulence determinants for bacterial pathogenesis and host infection. CONCLUSIONS This approach of in silico prediction of GIs and subsequent identification of potential virulence factors in the putative island regions with final validation using wet experiments could be used as an effective strategy to rapidly discover novel virulence factors in other bacterial species and strains.
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Affiliation(s)
- Feng-Biao Guo
- School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, 610054, China.,Center for Informational Biology, University of Electronic Science and Technology of China, Chengdu, 610054, China.,Key Laboratory for Neuro-information of the Ministry of Education, University of Electronic Science and Technology of China, Chengdu, 610054, China.,Department of Microbiology, The University of Hong Kong, Hong Kong, Special Administrative Region, People's Republic of China
| | - Lifeng Xiong
- Department of Microbiology, The University of Hong Kong, Hong Kong, Special Administrative Region, People's Republic of China
| | - Kai-Yue Zhang
- School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, 610054, China.,Center for Informational Biology, University of Electronic Science and Technology of China, Chengdu, 610054, China.,Key Laboratory for Neuro-information of the Ministry of Education, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Chuan Dong
- School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, 610054, China.,Center for Informational Biology, University of Electronic Science and Technology of China, Chengdu, 610054, China.,Key Laboratory for Neuro-information of the Ministry of Education, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Fa-Zhan Zhang
- School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, 610054, China.,Center for Informational Biology, University of Electronic Science and Technology of China, Chengdu, 610054, China.,Key Laboratory for Neuro-information of the Ministry of Education, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Patrick C Y Woo
- Department of Microbiology, The University of Hong Kong, Hong Kong, Special Administrative Region, People's Republic of China.
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Burkholderia cepacia Complex Regulation of Virulence Gene Expression: A Review. Genes (Basel) 2017; 8:genes8010043. [PMID: 28106859 PMCID: PMC5295037 DOI: 10.3390/genes8010043] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 01/11/2017] [Accepted: 01/12/2017] [Indexed: 12/31/2022] Open
Abstract
Burkholderia cepacia complex (Bcc) bacteria emerged as opportunistic pathogens in cystic fibrosis and immunocompromised patients. Their eradication is very difficult due to the high level of intrinsic resistance to clinically relevant antibiotics. Bcc bacteria have large and complex genomes, composed of two to four replicons, with variable numbers of insertion sequences. The complexity of Bcc genomes confers a high genomic plasticity to these bacteria, allowing their adaptation and survival to diverse habitats, including the human host. In this work, we review results from recent studies using omics approaches to elucidate in vivo adaptive strategies and virulence gene regulation expression of Bcc bacteria when infecting the human host or subject to conditions mimicking the stressful environment of the cystic fibrosis lung.
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24
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Moreira AS, Lourenço AB, Sá-Correia I. 1H-NMR-Based Endometabolome Profiles of Burkholderia cenocepacia Clonal Variants Retrieved from a Cystic Fibrosis Patient during Chronic Infection. Front Microbiol 2016; 7:2024. [PMID: 28066350 PMCID: PMC5167703 DOI: 10.3389/fmicb.2016.02024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 12/02/2016] [Indexed: 12/21/2022] Open
Abstract
During cystic fibrosis (CF) chronic lung infections, bacteria of the Burkholderia cepacia complex (Bcc) are exposed for several years to a stressful and changing environment. These environmental challenges results in genetic changes of the initial infecting strain with the consequent diversification of genotypes and phenotypes. The exploitation of functional and comparative genomic approaches has suggested that such diversification is associated with massive metabolic remodeling but these alterations are poorly understood. In the present work, we have explored a high resolution 1H-NMR-based metabolomic approach coupled to multivariate analysis to compare the endometabolome of three B. cenocepacia clonal variants retrieved from a CF patient from the onset of infection (IST439) until death with cepacia syndrome after 3.5 years (IST4113 and IST4134), to complement former proteomic and transcriptomic analyses. A fourth clonal variant (IST4129) retrieved from the same CF patient when the clinical condition worsened during the last months of life, was also examined since it was found to lack the third replicon. The metabolomic profiles obtained, based on the complete 1H-NMR spectra, highlight the separation of the four clonal variants examined, the most distinct profile corresponding to IST4129. Results indicate a variable content of several amino acids in the different isolates examined and suggest that glycolysis and the glyoxylate shunt are favored in late variants. Moreover, the concentration of two metabolites with demonstrated cellular protective functions against stress, glycine-betaine and trehalose, is different in the different isolates examined. However, no clear correlation could be established between their content and stress tolerance. For example, IST4113, previously found to be the most resistant variant to antimicrobials of different classes, exhibits low levels of trehalose and glycine-betaine but the highest resistance to heat and oxidative stress. Also, IST4129, with a high level of glycine-betaine but lacking the third replicon, previously associated with stress resistance and virulence, exhibits the highest susceptibility to all the stresses tested. Taken together, results from this study provide insights into the metabolic diversification of B. cenocepacia clonal variants during long-term infection of the CF airways.
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Affiliation(s)
- Ana S Moreira
- Department of Bioengineering, Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa (ULISBOA) Lisbon, Portugal
| | - Artur B Lourenço
- Department of Bioengineering, Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa (ULISBOA) Lisbon, Portugal
| | - Isabel Sá-Correia
- Department of Bioengineering, Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa (ULISBOA) Lisbon, Portugal
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25
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Using dendritic cells to evaluate how Burkholderia cenocepacia clonal isolates from a chronically infected cystic fibrosis patient subvert immune functions. Med Microbiol Immunol 2016; 206:111-123. [DOI: 10.1007/s00430-016-0488-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2016] [Accepted: 11/29/2016] [Indexed: 12/24/2022]
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26
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Pompilio A, Crocetta V, Ghosh D, Chakrabarti M, Gherardi G, Vitali LA, Fiscarelli E, Di Bonaventura G. Stenotrophomonas maltophilia Phenotypic and Genotypic Diversity during a 10-year Colonization in the Lungs of a Cystic Fibrosis Patient. Front Microbiol 2016; 7:1551. [PMID: 27746770 PMCID: PMC5044509 DOI: 10.3389/fmicb.2016.01551] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 09/15/2016] [Indexed: 11/25/2022] Open
Abstract
The present study was carried out to understand the adaptive strategies developed by Stenotrophomonas maltophilia for chronic colonization of the cystic fibrosis (CF) lung. For this purpose, 13 temporally isolated strains from a single CF patient chronically infected over a 10-year period were systematically characterized for growth rate, biofilm formation, motility, mutation frequencies, antibiotic resistance, and pathogenicity. Pulsed-field gel electrophoresis (PFGE) showed over time the presence of two distinct groups, each consisting of two different pulsotypes. The pattern of evolution followed by S. maltophilia was dependent on pulsotype considered, with strains belonging to pulsotype 1.1 resulting to be the most adapted, being significantly changed in all traits considered. Generally, S. maltophilia adaptation to CF lung leads to increased growth rate and antibiotic resistance, whereas both in vivo and in vitro pathogenicity as well as biofilm formation were decreased. Overall, our results show for the first time that S. maltophilia can successfully adapt to a highly stressful environment such as CF lung by paying a “biological cost,” as suggested by the presence of relevant genotypic and phenotypic heterogeneity within bacterial population. S. maltophilia populations are, therefore, significantly complex and dynamic being able to fluctuate rapidly under changing selective pressures.
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Affiliation(s)
- Arianna Pompilio
- Department of Medical, Oral, and Biotechnological Sciences, "G. d'Annunzio" University of Chieti-PescaraChieti, Italy; Center of Excellence on Aging and Translational Medicine (CeSI-MeT), "G. d'Annunzio" University of Chieti-PescaraChieti, Italy
| | - Valentina Crocetta
- Department of Medical, Oral, and Biotechnological Sciences, "G. d'Annunzio" University of Chieti-PescaraChieti, Italy; Center of Excellence on Aging and Translational Medicine (CeSI-MeT), "G. d'Annunzio" University of Chieti-PescaraChieti, Italy
| | - Dipankar Ghosh
- Special Center for Molecular Medicine, Jawaharlal Nehru University New Delhi, India
| | - Malabika Chakrabarti
- Special Center for Molecular Medicine, Jawaharlal Nehru University New Delhi, India
| | | | | | | | - Giovanni Di Bonaventura
- Department of Medical, Oral, and Biotechnological Sciences, "G. d'Annunzio" University of Chieti-PescaraChieti, Italy; Center of Excellence on Aging and Translational Medicine (CeSI-MeT), "G. d'Annunzio" University of Chieti-PescaraChieti, Italy
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27
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Moreira AS, Mil-Homens D, Sousa SA, Coutinho CP, Pinto-de-Oliveira A, Ramos CG, Dos Santos SC, Fialho AM, Leitão JH, Sá-Correia I. Variation of Burkholderia cenocepacia virulence potential during cystic fibrosis chronic lung infection. Virulence 2016; 8:782-796. [PMID: 27652671 DOI: 10.1080/21505594.2016.1237334] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
During long-term lung infection in cystic fibrosis (CF) patients, Burkholderia cenocepacia faces multiple selective pressures in this highly stressful and fluctuating environment. As a consequence, the initial infecting strain undergoes genetic changes that result in the diversification of genotypes and phenotypes. Whether this clonal expansion influences the pathogenic potential is unclear. The virulence potential of 39 sequential B. cenocepacia (recA lineage IIIA) isolates, corresponding to 3 different clones retrieved from 3 chronically infected CF patients was compared in this study using the non-mammalian infection hosts Galleria mellonella and Caenorhabditis elegans. The isolates used in this retrospective study were picked randomly from selective agar plates as part of a CF Center routine, from the onset of infection until patients' death after 3.5 and 7.5 y or the more recent isolation date after 12.5 y of chronic infection. The infection models proved useful to assess virulence potential diversification, but for some isolates the relative values diverged in C. elegans and G. mellonella. Results also reinforce the concept of the occurrence of clonal diversification and co-existence of multiple phenotypes within the CF lungs, also with respect to pathogenicity. No clear trend of decrease (or increase) of the virulence potential throughout long-term infection was found but there is an apparent tendency for a clone/patient-dependent decrease of virulence when the G. mellonella model was used. The sole avirulent variant in both infection hosts was found to lack the small third replicon previously associated to virulence. Although possible, the in vivo loss of this nonessential megaplasmid was found to be a rare event (1 among a total of 64 isolates examined).
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Affiliation(s)
- Ana S Moreira
- a iBB-Institute for Bioengineering and Biosciences , Department of Bioengineering , Instituto Superior Técnico, Universidade de Lisboa , Lisbon , Portugal
| | - Dalila Mil-Homens
- a iBB-Institute for Bioengineering and Biosciences , Department of Bioengineering , Instituto Superior Técnico, Universidade de Lisboa , Lisbon , Portugal
| | - Sílvia A Sousa
- a iBB-Institute for Bioengineering and Biosciences , Department of Bioengineering , Instituto Superior Técnico, Universidade de Lisboa , Lisbon , Portugal
| | - Carla P Coutinho
- a iBB-Institute for Bioengineering and Biosciences , Department of Bioengineering , Instituto Superior Técnico, Universidade de Lisboa , Lisbon , Portugal
| | - Ana Pinto-de-Oliveira
- a iBB-Institute for Bioengineering and Biosciences , Department of Bioengineering , Instituto Superior Técnico, Universidade de Lisboa , Lisbon , Portugal
| | - Christian G Ramos
- a iBB-Institute for Bioengineering and Biosciences , Department of Bioengineering , Instituto Superior Técnico, Universidade de Lisboa , Lisbon , Portugal
| | - Sandra C Dos Santos
- a iBB-Institute for Bioengineering and Biosciences , Department of Bioengineering , Instituto Superior Técnico, Universidade de Lisboa , Lisbon , Portugal
| | - Arsénio M Fialho
- a iBB-Institute for Bioengineering and Biosciences , Department of Bioengineering , Instituto Superior Técnico, Universidade de Lisboa , Lisbon , Portugal
| | - Jorge H Leitão
- a iBB-Institute for Bioengineering and Biosciences , Department of Bioengineering , Instituto Superior Técnico, Universidade de Lisboa , Lisbon , Portugal
| | - Isabel Sá-Correia
- a iBB-Institute for Bioengineering and Biosciences , Department of Bioengineering , Instituto Superior Técnico, Universidade de Lisboa , Lisbon , Portugal
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28
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Nunvar J, Kalferstova L, Bloodworth RAM, Kolar M, Degrossi J, Lubovich S, Cardona ST, Drevinek P. Understanding the Pathogenicity of Burkholderia contaminans, an Emerging Pathogen in Cystic Fibrosis. PLoS One 2016; 11:e0160975. [PMID: 27512997 PMCID: PMC4981469 DOI: 10.1371/journal.pone.0160975] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 07/27/2016] [Indexed: 12/22/2022] Open
Abstract
Several bacterial species from the Burkholderia cepacia complex (Bcc) are feared opportunistic pathogens that lead to debilitating lung infections with a high risk of developing fatal septicemia in cystic fibrosis (CF) patients. However, the pathogenic potential of other Bcc species is yet unknown. To elucidate clinical relevance of Burkholderia contaminans, a species frequently isolated from CF respiratory samples in Ibero-American countries, we aimed to identify its key virulence factors possibly linked with an unfavorable clinical outcome. We performed a genome-wide comparative analysis of two isolates of B. contaminans ST872 from sputum and blood culture of a female CF patient in Argentina. RNA-seq data showed significant changes in expression for quorum sensing-regulated virulence factors and motility and chemotaxis. Furthermore, we detected expression changes in a recently described low-oxygen-activated (lxa) locus which encodes stress-related proteins, and for two clusters responsible for the biosynthesis of antifungal and hemolytic compounds pyrrolnitrin and occidiofungin. Based on phenotypic assays that confirmed changes in motility and in proteolytic, hemolytic and antifungal activities, we were able to distinguish two phenotypes of B. contaminans that coexisted in the host and entered her bloodstream. Whole genome sequencing revealed that the sputum and bloodstream isolates (each representing a distinct phenotype) differed by over 1,400 mutations as a result of a mismatch repair-deficient hypermutable state of the sputum isolate. The inferred lack of purifying selection against nonsynonymous mutations and the high rate of pseudogenization in the derived isolate indicated limited evolutionary pressure during evolution in the nutrient-rich, stable CF sputum environment. The present study is the first to examine the genomic and transcriptomic differences between longitudinal isolates of B. contaminans. Detected activity of a number of putative virulence factors implies a genuine pathogenic nature of this novel Bcc species.
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Affiliation(s)
- Jaroslav Nunvar
- Department of Medical Microbiology, 2nd Faculty of Medicine, Charles University and Motol University Hospital, Prague, Czech Republic
| | - Lucie Kalferstova
- Department of Medical Microbiology, 2nd Faculty of Medicine, Charles University and Motol University Hospital, Prague, Czech Republic
| | - Ruhi A. M. Bloodworth
- Department of Medical Microbiology & Infectious Disease, University of Manitoba, Winnipeg, Canada
| | - Michal Kolar
- Laboratory of Genomics and Bioinformatics, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Jose Degrossi
- School of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires, Argentina
| | - Silvina Lubovich
- Centro Respiratorio Dr. A. Alvarez, Hospital de Niños Ricardo Gutiérrez, Buenos Aires, Argentina
| | - Silvia T. Cardona
- Department of Medical Microbiology & Infectious Disease, University of Manitoba, Winnipeg, Canada
| | - Pavel Drevinek
- Department of Medical Microbiology, 2nd Faculty of Medicine, Charles University and Motol University Hospital, Prague, Czech Republic
- * E-mail:
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29
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Maldonado RF, Sá-Correia I, Valvano MA. Lipopolysaccharide modification in Gram-negative bacteria during chronic infection. FEMS Microbiol Rev 2016; 40:480-93. [PMID: 27075488 PMCID: PMC4931227 DOI: 10.1093/femsre/fuw007] [Citation(s) in RCA: 350] [Impact Index Per Article: 43.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 08/23/2015] [Accepted: 03/10/2016] [Indexed: 12/16/2022] Open
Abstract
The Gram-negative bacterial lipopolysaccharide (LPS) is a major component of the outer membrane that plays a key role in host-pathogen interactions with the innate immune system. During infection, bacteria are exposed to a host environment that is typically dominated by inflammatory cells and soluble factors, including antibiotics, which provide cues about regulation of gene expression. Bacterial adaptive changes including modulation of LPS synthesis and structure are a conserved theme in infections, irrespective of the type or bacteria or the site of infection. In general, these changes result in immune system evasion, persisting inflammation and increased antimicrobial resistance. Here, we review the modifications of LPS structure and biosynthetic pathways that occur upon adaptation of model opportunistic pathogens (Pseudomonas aeruginosa, Burkholderia cepacia complex bacteria, Helicobacter pylori and Salmonella enterica) to chronic infection in respiratory and gastrointestinal sites. We also discuss the molecular mechanisms of these variations and their role in the host-pathogen interaction.
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Affiliation(s)
- Rita F. Maldonado
- Institute for Bioengineering and Biosciences, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon 1049-001, Portugal
| | - Isabel Sá-Correia
- Institute for Bioengineering and Biosciences, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon 1049-001, Portugal
| | - Miguel A. Valvano
- Department of Microbiology and Immunology, University of Western Ontario, London, ON N6A 5C1, Canada
- Centre for Infection and Immunity, Queen's University Belfast, Belfast BT9 7BL, UK
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30
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Shommu NS, Vogel HJ, Storey DG. Potential of metabolomics to reveal Burkholderia cepacia complex pathogenesis and antibiotic resistance. Front Microbiol 2015. [PMID: 26217312 PMCID: PMC4499752 DOI: 10.3389/fmicb.2015.00668] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The Burkholderia cepacia complex (Bcc) is a collection of closely related, genetically distinct, ecologically diverse species known to cause life-threatening infections in cystic fibrosis (CF) patients. By virtue of a flexible genomic structure and diverse metabolic activity, Bcc bacteria employ a wide array of virulence factors for pathogenesis in CF patients and have developed resistance to most of the commonly used antibiotics. However, the mechanism of pathogenesis and antibiotic resistance is still not fully understood. This mini review discusses the established and potential virulence determinants of Bcc and some of the contemporary strategies including transcriptomics and proteomics used to identify these traits. We also propose the application of metabolic profiling, a cost-effective modern-day approach to achieve new insights.
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Affiliation(s)
- Nusrat S Shommu
- Biochemistry Research Group, Department of Biological Sciences, University of Calgary , Calgary, AB, Canada
| | - Hans J Vogel
- Biochemistry Research Group, Department of Biological Sciences, University of Calgary , Calgary, AB, Canada
| | - Douglas G Storey
- Microbiology Research Group, Department of Biological Sciences, University of Calgary , Calgary, AB, Canada
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31
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Podnecky NL, Rhodes KA, Schweizer HP. Efflux pump-mediated drug resistance in Burkholderia. Front Microbiol 2015; 6:305. [PMID: 25926825 PMCID: PMC4396416 DOI: 10.3389/fmicb.2015.00305] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Accepted: 03/27/2015] [Indexed: 12/17/2022] Open
Abstract
Several members of the genus Burkholderia are prominent pathogens. Infections caused by these bacteria are difficult to treat because of significant antibiotic resistance. Virtually all Burkholderia species are also resistant to polymyxin, prohibiting use of drugs like colistin that are available for treatment of infections caused by most other drug resistant Gram-negative bacteria. Despite clinical significance and antibiotic resistance of Burkholderia species, characterization of efflux pumps lags behind other non-enteric Gram-negative pathogens such as Acinetobacter baumannii and Pseudomonas aeruginosa. Although efflux pumps have been described in several Burkholderia species, they have been best studied in Burkholderia cenocepacia and B. pseudomallei. As in other non-enteric Gram-negatives, efflux pumps of the resistance nodulation cell division (RND) family are the clinically most significant efflux systems in these two species. Several efflux pumps were described in B. cenocepacia, which when expressed confer resistance to clinically significant antibiotics, including aminoglycosides, chloramphenicol, fluoroquinolones, and tetracyclines. Three RND pumps have been characterized in B. pseudomallei, two of which confer either intrinsic or acquired resistance to aminoglycosides, macrolides, chloramphenicol, fluoroquinolones, tetracyclines, trimethoprim, and in some instances trimethoprim+sulfamethoxazole. Several strains of the host-adapted B. mallei, a clone of B. pseudomallei, lack AmrAB-OprA, and are therefore aminoglycoside and macrolide susceptible. B. thailandensis is closely related to B. pseudomallei, but non-pathogenic to humans. Its pump repertoire and ensuing drug resistance profile parallels that of B. pseudomallei. An efflux pump in B. vietnamiensis plays a significant role in acquired aminoglycoside resistance. Summarily, efflux pumps are significant players in Burkholderia drug resistance.
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Affiliation(s)
- Nicole L Podnecky
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biological Sciences, Colorado State University Fort Collins, CO, USA
| | - Katherine A Rhodes
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biological Sciences, Colorado State University Fort Collins, CO, USA ; Department of Molecular Genetics and Microbiology, College of Medicine, Emerging Pathogens Institute, Institute for Therapeutic Innovation, University of Florida Gainesville, FL, USA
| | - Herbert P Schweizer
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biological Sciences, Colorado State University Fort Collins, CO, USA ; Department of Molecular Genetics and Microbiology, College of Medicine, Emerging Pathogens Institute, Institute for Therapeutic Innovation, University of Florida Gainesville, FL, USA
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32
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Franke J, Ishida K, Hertweck C. Plasticity of the Malleobactin Pathway and Its Impact on Siderophore Action in Human Pathogenic Bacteria. Chemistry 2015; 21:8010-4. [DOI: 10.1002/chem.201500757] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Indexed: 12/23/2022]
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33
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σ54-Dependent Response to Nitrogen Limitation and Virulence in Burkholderia cenocepacia Strain H111. Appl Environ Microbiol 2015; 81:4077-89. [PMID: 25841012 DOI: 10.1128/aem.00694-15] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 03/31/2015] [Indexed: 11/20/2022] Open
Abstract
Members of the genus Burkholderia are versatile bacteria capable of colonizing highly diverse environmental niches. In this study, we investigated the global response of the opportunistic pathogen Burkholderia cenocepacia H111 to nitrogen limitation at the transcript and protein expression levels. In addition to a classical response to nitrogen starvation, including the activation of glutamine synthetase, PII proteins, and the two-component regulatory system NtrBC, B. cenocepacia H111 also upregulated polyhydroxybutyrate (PHB) accumulation and exopolysaccharide (EPS) production in response to nitrogen shortage. A search for consensus sequences in promoter regions of nitrogen-responsive genes identified a σ(54) consensus sequence. The mapping of the σ(54) regulon as well as the characterization of a σ(54) mutant suggests an important role of σ(54) not only in control of nitrogen metabolism but also in the virulence of this organism.
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34
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Bacterial Adaptation during Chronic Respiratory Infections. Pathogens 2015; 4:66-89. [PMID: 25738646 PMCID: PMC4384073 DOI: 10.3390/pathogens4010066] [Citation(s) in RCA: 111] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 02/15/2015] [Accepted: 02/25/2015] [Indexed: 01/22/2023] Open
Abstract
Chronic lung infections are associated with increased morbidity and mortality for individuals with underlying respiratory conditions such as cystic fibrosis (CF) and chronic obstructive pulmonary disease (COPD). The process of chronic colonisation allows pathogens to adapt over time to cope with changing selection pressures, co-infecting species and antimicrobial therapies. These adaptations can occur due to environmental pressures in the lung such as inflammatory responses, hypoxia, nutrient deficiency, osmolarity, low pH and antibiotic therapies. Phenotypic adaptations in bacterial pathogens from acute to chronic infection include, but are not limited to, antibiotic resistance, exopolysaccharide production (mucoidy), loss in motility, formation of small colony variants, increased mutation rate, quorum sensing and altered production of virulence factors associated with chronic infection. The evolution of Pseudomonas aeruginosa during chronic lung infection has been widely studied. More recently, the adaptations that other chronically colonising respiratory pathogens, including Staphylococcus aureus, Burkholderia cepacia complex and Haemophilus influenzae undergo during chronic infection have also been investigated. This review aims to examine the adaptations utilised by different bacterial pathogens to aid in their evolution from acute to chronic pathogens of the immunocompromised lung including CF and COPD.
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35
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Gene expression profiling of Burkholderia cenocepacia at the time of cepacia syndrome: loss of motility as a marker of poor prognosis? J Clin Microbiol 2015; 53:1515-22. [PMID: 25694518 DOI: 10.1128/jcm.03605-14] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 02/11/2015] [Indexed: 11/20/2022] Open
Abstract
Cepacia syndrome (CS) is a fatal septic condition that develops in approximately 20% of cystic fibrosis (CF) patients chronically infected with the Burkholderia cepacia complex (Bcc). The most common causative agent is Burkholderia cenocepacia, a clinically dominant Bcc species that contains the globally distributed epidemic strain sequence type 32 (ST32). Using microarrays, we compared the transcriptomes of ST32 isolates from the bloodstream at the time of CS with their sputum counterparts recovered 1 to 2 months prior to the development of CS. Global gene expression profiles of blood isolates revealed greater activities of the virulence genes involved in the type III secretion system, the bacterial exopolysaccharide cepacian, and quorum sensing, while reduced expression was demonstrated for flagellar genes. Furthermore, a nonmotile phenotype (as evaluated by a swimming motility assay) was identified in blood isolates from 6 out of 8 patients with CS; this phenotype was traceable to 24 months prior to the onset of CS. Loss of motility was not observed in any of the 89 ST32 isolates recovered over the course of chronic infection from 17 patients without CS. In conclusion, the gene expression of Bcc bacteria disseminated during CS has been elucidated for the first time. This study demonstrated marked differences at the transcriptome level between isogenic ST32 isolates that are attributable to the stage and site of infection. The finding of a nonmotile B. cenocepacia isolate may serve as a warning sign for the development of CS in the near future.
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36
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Hosseinkhan N, Zarrineh P, Masoudi-Nejad A. Analysis of Genome-scale Expression Network in Four Major Bacterial Residents of Cystic Fibrosis Lung. Curr Genomics 2014; 15:408-18. [PMID: 25435803 PMCID: PMC4245700 DOI: 10.2174/1389202915666140818205444] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Revised: 07/06/2014] [Accepted: 08/15/2014] [Indexed: 11/22/2022] Open
Abstract
In polymicrobial communities where several species co-exist in a certain niche and consequently the possibility of interactions among species is very high, gene expression data sources can give better insights in to underlying adaptation mechanisms assumed by bacteria. Furthermore, several possible synergistic or antagonistic interactions among species can be investigated through gene expression comparisons. Lung is one of the habitats harboring several distinct pathogens during severe pulmonary disorders such as chronic obstructive pulmonary disease (COPD) and cystic fibrosis (CF). Expression data analysis of these lung residents can help to gain a better understanding on how these species interact with each other within the host cells. The first part of this paper deals with introducing available data sources for the major bacteria responsible for causing lung diseases and their genomic relations. In the second part, the main focus is on the studies concerning gene expression analyses of these species.
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Affiliation(s)
- Nazanin Hosseinkhan
- Laboratory of Systems Biology and Bioinformatics (LBB), Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran
| | - Peyman Zarrineh
- Laboratory of Systems Biology and Bioinformatics (LBB), Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran
| | - Ali Masoudi-Nejad
- Laboratory of Systems Biology and Bioinformatics (LBB), Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran
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Comparison of Raman spectroscopy and two molecular diagnostic methods for Burkholderia cepacia complex species identification. J Microbiol Methods 2014; 107:126-32. [DOI: 10.1016/j.mimet.2014.10.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Revised: 09/09/2014] [Accepted: 10/02/2014] [Indexed: 01/22/2023]
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Zlosnik JEA, Mori PY, To D, Leung J, Hird TJ, Speert DP. Swimming motility in a longitudinal collection of clinical isolates of Burkholderia cepacia complex bacteria from people with cystic fibrosis. PLoS One 2014; 9:e106428. [PMID: 25203161 PMCID: PMC4159263 DOI: 10.1371/journal.pone.0106428] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Accepted: 07/29/2014] [Indexed: 12/13/2022] Open
Abstract
Chronic bacterial lung infections in cystic fibrosis (CF) are the leading cause of morbidity and mortality. While a range of bacteria are known to be capable of establishing residence in the CF lung, only a small number have a clearly established link to deteriorating clinical status. The two bacteria with the clearest roles in CF lung disease are Pseudomonas aeruginosa and bacteria belonging to the Burkholderia cepacia complex (BCC). A number of common adaptations by P. aeruginosa strains to chronic lung infection in CF have been well described. Typically, initial isolates of P. aeruginosa are nonmucoid and display a range of putative virulence determinants. Upon establishment of chronic infection, subsequent isolates ultimately show a reduction in putative virulence determinants, including swimming motility, along with an acquisition of the mucoid phenotype and increased levels of antimicrobial resistance. Infections by BCC are marked by an unpredictable, but typically worse, clinical outcome. However, in contrast to P. aeruginosa infections in CF, studies describing adaptive changes in BCC bacterial phenotype during chronic lung infections are far more limited. To further enhance our understanding of chronic lung infections by BCC bacteria in CF, we assessed the swimming motility phenotype in 551 isolates of BCC bacteria from cystic fibrosis (CF) lung infections between 1981 and 2007. These data suggest that swimming motility is not typically lost by BCC during chronic infection, unlike as seen in P. aeruginosa infections. Furthermore, while we observed a statistically significant link between mucoidy and motility, we did not detect any link between motility phenotype and clinical outcome. These studies highlight the need for further work to understand the adaptive changes of BCC bacteria during chronic infection in the CF lung.
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Affiliation(s)
- James E. A. Zlosnik
- Centre for Understanding and Preventing Infection in Children, Department of Pediatrics, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
- * E-mail:
| | - Paul Y. Mori
- Centre for Understanding and Preventing Infection in Children, Department of Pediatrics, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Derek To
- Centre for Understanding and Preventing Infection in Children, Department of Pediatrics, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - James Leung
- Centre for Understanding and Preventing Infection in Children, Department of Pediatrics, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Trevor J. Hird
- Centre for Understanding and Preventing Infection in Children, Department of Pediatrics, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - David P. Speert
- Centre for Understanding and Preventing Infection in Children, Department of Pediatrics, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
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Martina P, Feliziani S, Juan C, Bettiol M, Gatti B, Yantorno O, Smania AM, Oliver A, Bosch A. Hypermutation in Burkholderia cepacia complex is mediated by DNA mismatch repair inactivation and is highly prevalent in cystic fibrosis chronic respiratory infection. Int J Med Microbiol 2014; 304:1182-91. [PMID: 25217078 DOI: 10.1016/j.ijmm.2014.08.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2014] [Revised: 08/15/2014] [Accepted: 08/18/2014] [Indexed: 11/25/2022] Open
Abstract
The Burkholderia cepacia complex (Bcc) represents an important group of pathogens involved in long-term lung infection in cystic fibrosis (CF) patients. A positive selection of hypermutators, linked to antimicrobial resistance development, has been previously reported for Pseudomonas aeruginosa in this chronic infection setting. Hypermutability, however, has not yet been systematically evaluated in Bcc species. A total of 125 well characterized Bcc isolates recovered from 48 CF patients, 10 non-CF patients and 15 environmental samples were analyzed. In order to determine the prevalence of mutators their spontaneous mutation rates to rifampicin resistance were determined. In addition, the genetic basis of the mutator phenotypes was investigated by sequencing the mutS and mutL genes, the main components of the mismatch repair system (MRS). The overall prevalence of hypermutators in the collection analyzed was 13.6%, with highest occurrence (40.7%) among the chronically infected CF patients, belonging mainly to B. cenocepacia, B. multivorans, B. cepacia, and B. contaminans -the most frequently recovered Bcc species from CF patients worldwide. Thirteen (76.5%) of the hypermutators were defective in mutS and/or mutL. Finally, searching for a possible association between antimicrobial resistance and hypermutability, the resistance-profiles to 17 antimicrobial agents was evaluated. High antimicrobial resistance rates were documented for all the Bcc species recovered from CF patients, but, except for ciprofloxacin, a significant association with hypermutation was not detected. In conclusion, in the present study we demonstrate for the first time that, MRS-deficient Bcc species mutators are highly prevalent and positively selected in CF chronic lung infections. Hypermutation therefore, might be playing a key role in increasing bacterial adaptability to the CF-airway environment, facilitating the persistence of chronic lung infections.
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Affiliation(s)
- Pablo Martina
- CINDEFI-CONICET-CCT La Plata, Centro de Biotecnología Aplicada, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, 1900 La Plata, Argentina
| | - Sofía Feliziani
- CIQUIBIC-CONICET, Centro de Investigaciones en Química Biológica de Córdoba, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, X5000HUA Córdoba, Argentina
| | - Carlos Juan
- Servicio de Microbiología y Unidad de Investigación, Hospital Universitario Son Espases, Instituto de Investigación Sanitaria de Palma (IdISPa), 07010 Palma de Mallorca, Spain
| | - Marisa Bettiol
- Sala de Microbiología, Hospital de Niños de La Plata "Sor María Ludovica", 1900 La Plata, Argentina
| | - Blanca Gatti
- Sala de Microbiología, Hospital de Niños de La Plata "Sor María Ludovica", 1900 La Plata, Argentina
| | - Osvaldo Yantorno
- CINDEFI-CONICET-CCT La Plata, Centro de Biotecnología Aplicada, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, 1900 La Plata, Argentina
| | - Andrea M Smania
- CIQUIBIC-CONICET, Centro de Investigaciones en Química Biológica de Córdoba, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, X5000HUA Córdoba, Argentina
| | - Antonio Oliver
- Servicio de Microbiología y Unidad de Investigación, Hospital Universitario Son Espases, Instituto de Investigación Sanitaria de Palma (IdISPa), 07010 Palma de Mallorca, Spain.
| | - Alejandra Bosch
- CINDEFI-CONICET-CCT La Plata, Centro de Biotecnología Aplicada, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, 1900 La Plata, Argentina.
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McGuigan L, Callaghan M. The evolving dynamics of the microbial community in the cystic fibrosis lung. Environ Microbiol 2014; 17:16-28. [DOI: 10.1111/1462-2920.12504] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 04/28/2014] [Accepted: 05/01/2014] [Indexed: 12/29/2022]
Affiliation(s)
- Luke McGuigan
- Department of Science; Centre of Microbial Host Interactions (CMHI); ITT-Dublin; Dublin Ireland
| | - Máire Callaghan
- Department of Science; Centre of Microbial Host Interactions (CMHI); ITT-Dublin; Dublin Ireland
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Garmendia J, Viadas C, Calatayud L, Mell JC, Martí-Lliteras P, Euba B, Llobet E, Gil C, Bengoechea JA, Redfield RJ, Liñares J. Characterization of nontypable Haemophilus influenzae isolates recovered from adult patients with underlying chronic lung disease reveals genotypic and phenotypic traits associated with persistent infection. PLoS One 2014; 9:e97020. [PMID: 24824990 PMCID: PMC4019658 DOI: 10.1371/journal.pone.0097020] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Accepted: 04/14/2014] [Indexed: 01/09/2023] Open
Abstract
Nontypable Haemophilus influenzae (NTHi) has emerged as an important opportunistic pathogen causing infection in adults suffering obstructive lung diseases. Existing evidence associates chronic infection by NTHi to the progression of the chronic respiratory disease, but specific features of NTHi associated with persistence have not been comprehensively addressed. To provide clues about adaptive strategies adopted by NTHi during persistent infection, we compared sequential persistent isolates with newly acquired isolates in sputa from six patients with chronic obstructive lung disease. Pulse field gel electrophoresis (PFGE) identified three patients with consecutive persistent strains and three with new strains. Phenotypic characterisation included infection of respiratory epithelial cells, bacterial self-aggregation, biofilm formation and resistance to antimicrobial peptides (AMP). Persistent isolates differed from new strains in showing low epithelial adhesion and inability to form biofilms when grown under continuous-flow culture conditions in microfermenters. Self-aggregation clustered the strains by patient, not by persistence. Increasing resistance to AMPs was observed for each series of persistent isolates; this was not associated with lipooligosaccharide decoration with phosphorylcholine or with lipid A acylation. Variation was further analyzed for the series of three persistent isolates recovered from patient 1. These isolates displayed comparable growth rate, natural transformation frequency and murine pulmonary infection. Genome sequencing of these three isolates revealed sequential acquisition of single-nucleotide variants in the AMP permease sapC, the heme acquisition systems hgpB, hgpC, hup and hxuC, the 3-deoxy-D-manno-octulosonic acid kinase kdkA, the long-chain fatty acid transporter ompP1, and the phosphoribosylamine glycine ligase purD. Collectively, we frame a range of pathogenic traits and a repertoire of genetic variants in the context of persistent infection by NTHi.
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Affiliation(s)
- Junkal Garmendia
- Instituto de Agrobiotecnología, CSIC-Universidad Pública Navarra-Gobierno Navarra, Mutilva, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Madrid, Spain
- Laboratory Microbial Pathogenesis, Fundación Investigación Sanitaria Illes Balears, Bunyola, Spain
- * E-mail:
| | - Cristina Viadas
- Instituto de Agrobiotecnología, CSIC-Universidad Pública Navarra-Gobierno Navarra, Mutilva, Spain
| | - Laura Calatayud
- Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Madrid, Spain
- Microbiology Department, University Hospital Bellvitge, IDIBELL, University of Barcelona, Barcelona, Spain
| | - Joshua Chang Mell
- Department of Zoology, University British Columbia, Vancouver, British Columbia, Canada
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Pau Martí-Lliteras
- Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Madrid, Spain
- Laboratory Microbial Pathogenesis, Fundación Investigación Sanitaria Illes Balears, Bunyola, Spain
| | - Begoña Euba
- Instituto de Agrobiotecnología, CSIC-Universidad Pública Navarra-Gobierno Navarra, Mutilva, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Madrid, Spain
| | - Enrique Llobet
- Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Madrid, Spain
- Laboratory Microbial Pathogenesis, Fundación Investigación Sanitaria Illes Balears, Bunyola, Spain
| | - Carmen Gil
- Instituto de Agrobiotecnología, CSIC-Universidad Pública Navarra-Gobierno Navarra, Mutilva, Spain
| | - José Antonio Bengoechea
- Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Madrid, Spain
- Laboratory Microbial Pathogenesis, Fundación Investigación Sanitaria Illes Balears, Bunyola, Spain
- Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Rosemary J. Redfield
- Department of Zoology, University British Columbia, Vancouver, British Columbia, Canada
| | - Josefina Liñares
- Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Madrid, Spain
- Microbiology Department, University Hospital Bellvitge, IDIBELL, University of Barcelona, Barcelona, Spain
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Sharma P, Gupta SK, Rolain JM. Whole genome sequencing of bacteria in cystic fibrosis as a model for bacterial genome adaptation and evolution. Expert Rev Anti Infect Ther 2014; 12:343-55. [PMID: 24502835 DOI: 10.1586/14787210.2014.887441] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Cystic fibrosis (CF) airways harbor a wide variety of new and/or emerging multidrug resistant bacteria which impose a heavy burden on patients. These bacteria live in close proximity with one another, which increases the frequency of lateral gene transfer. The exchange and movement of mobile genetic elements and genomic islands facilitate the spread of genes between genetically diverse bacteria, which seem to be advantageous to the bacterium as it allows adaptation to the new niches of the CF lungs. Niche adaptation is one of the major evolutionary forces shaping bacterial genome composition and in CF the chronic strains adapt and become less virulent. The purpose of this review is to shed light on CF bacterial genome alterations. Next-generation sequencing technology is an exciting tool that may help us to decipher the genome architecture and the evolution of bacteria colonizing CF lungs.
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Affiliation(s)
- Poonam Sharma
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergents, CNRS-IRD, UMR 7278, IHU Méditerranée Infection, Faculté de Médecine et de Pharmacie, Aix-Marseille Université, 27 Bd Jean-Moulin, Marseille Cedex 05 13385, France
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Moreira AS, Coutinho CP, Azevedo P, Lito L, Melo-Cristino J, Sá-Correia I. Burkholderia dolosa phenotypic variation during the decline in lung function of a cystic fibrosis patient during 5.5 years of chronic colonization. J Med Microbiol 2014; 63:594-601. [PMID: 24469681 DOI: 10.1099/jmm.0.069849-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Although rarely isolated from cystic fibrosis (CF) patients, Burkholderia dolosa is associated with accelerated lung function decline. During 18 years of epidemiological surveillance in the major Portuguese CF centre in Lisbon, only one patient was infected with B. dolosa. Pulmonary deterioration, associated with the evolution of forced expiratory volume in 1 s, occurred during 5.5 years of colonization with this B. dolosa clone (with the new sequence type ST-668). Transient co-colonization with Burkholderia cenocepacia and other bacterial and fungal pathogens occurred, but B. dolosa prevailed until the patient's death. The systematic assessment of relevant phenotypes for the sequential clonal isolates examined in this retrospective study (14 of B. dolosa and four of B. cenocepacia) showed that they were variants, although in general no isolation time-dependent pattern of alteration was identified. However, the first B. dolosa isolate retrieved was more susceptible to gentamicin, imipenem and tobramycin, and exhibited a higher swarming motility compared with most of the isolates obtained during the later stages of disease progression and antimicrobial therapy.
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Affiliation(s)
- Ana Sílvia Moreira
- IBB - Institute for Biotechnology and Bioengineering, Centre for Biological and Chemical Engineering, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
| | - Carla P Coutinho
- IBB - Institute for Biotechnology and Bioengineering, Centre for Biological and Chemical Engineering, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
| | - Pilar Azevedo
- Consulta de Fibrose Quística, Unidade de Pneumologia, Hospital de Santa Maria, Av. Prof. Egas Moniz, 1649-028 Lisbon, Portugal
| | - Luís Lito
- Laboratório de Patologia Clínica, Hospital de Santa Maria, Av. Prof. Egas Moniz, 1649-028 Lisbon, Portugal
| | - José Melo-Cristino
- Laboratório de Patologia Clínica, Hospital de Santa Maria, Av. Prof. Egas Moniz, 1649-028 Lisbon, Portugal
| | - Isabel Sá-Correia
- IBB - Institute for Biotechnology and Bioengineering, Centre for Biological and Chemical Engineering, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
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44
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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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45
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Madeira A, dos Santos SC, Santos PM, Coutinho CP, Tyrrell J, McClean S, Callaghan M, Sá-Correia I. Proteomic profiling of Burkholderia cenocepacia clonal isolates with different virulence potential retrieved from a cystic fibrosis patient during chronic lung infection. PLoS One 2013; 8:e83065. [PMID: 24349432 PMCID: PMC3862766 DOI: 10.1371/journal.pone.0083065] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Accepted: 11/07/2013] [Indexed: 11/18/2022] Open
Abstract
Respiratory infections with Burkholderia cepacia complex (Bcc) bacteria in cystic fibrosis (CF) are associated with a worse prognosis and increased risk of death. In this work, we assessed the virulence potential of three B. cenocepacia clonal isolates obtained from a CF patient between the onset of infection (isolate IST439) and before death with cepacia syndrome 3.5 years later (isolate IST4113 followed by IST4134), based on their ability to invade epithelial cells and compromise epithelial monolayer integrity. The two clonal isolates retrieved during late-stage disease were significantly more virulent than IST439. Proteomic profiling by 2-D DIGE of the last isolate recovered before the patient’s death, IST4134, and clonal isolate IST439, was performed and compared with a prior analysis of IST4113 vs. IST439. The cytoplasmic and membrane-associated enriched fractions were examined and 52 proteins were found to be similarly altered in the two last isolates compared with IST439. These proteins are involved in metabolic functions, nucleotide synthesis, translation and protein folding, cell envelope biogenesis and iron homeostasis. Results are suggestive of the important role played by metabolic reprogramming in the virulence potential and persistence of B. cenocepacia, in particular regarding bacterial adaptation to microaerophilic conditions. Also, the content of the virulence determinant AidA was higher in the last 2 isolates. Significant levels of siderophores were found to be secreted by the three clonal isolates in an iron-depleted environment, but the two late isolates were more tolerant to low iron concentrations than IST439, consistent with the relative abundance of proteins involved in iron uptake.
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Affiliation(s)
- Andreia Madeira
- Institute for Biotechnology and Bioengineering, Centre for Biological and Chemical Engineering, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Sandra C. dos Santos
- Institute for Biotechnology and Bioengineering, Centre for Biological and Chemical Engineering, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Pedro M. Santos
- Institute for Biotechnology and Bioengineering, Centre for Biological and Chemical Engineering, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Carla P. Coutinho
- Institute for Biotechnology and Bioengineering, Centre for Biological and Chemical Engineering, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Jean Tyrrell
- Centre of Microbial Host Interactions, Department of Science, ITT-Dublin, Dublin, Ireland
| | - Siobhán McClean
- Centre of Microbial Host Interactions, Department of Science, ITT-Dublin, Dublin, Ireland
| | - Máire Callaghan
- Centre of Microbial Host Interactions, Department of Science, ITT-Dublin, Dublin, Ireland
| | - Isabel Sá-Correia
- Institute for Biotechnology and Bioengineering, Centre for Biological and Chemical Engineering, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
- * E-mail:
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Common duckweed (Lemna minor) is a versatile high-throughput infection model for the Burkholderia cepacia complex and other pathogenic bacteria. PLoS One 2013; 8:e80102. [PMID: 24223216 PMCID: PMC3819297 DOI: 10.1371/journal.pone.0080102] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Accepted: 10/07/2013] [Indexed: 01/05/2023] Open
Abstract
Members of the Burkholderia cepacia complex (Bcc) have emerged in recent decades as problematic pulmonary pathogens of cystic fibrosis (CF) patients, with severe infections progressing to acute necrotizing pneumonia and sepsis. This study presents evidence that Lemna minor (Common duckweed) is useful as a plant model for the Bcc infectious process, and has potential as a model system for bacterial pathogenesis in general. To investigate the relationship between Bcc virulence in duckweed and Galleria mellonella (Greater wax moth) larvae, a previously established Bcc infection model, a duckweed survival assay was developed and used to determine LD50 values. A strong correlation (R2 = 0.81) was found between the strains’ virulence ranks in the two infection models, suggesting conserved pathways in these vastly different hosts. To broaden the application of the duckweed model, enteropathogenic Escherichia coli (EPEC) and five isogenic mutants with previously established LD50 values in the larval model were tested against duckweed, and a strong correlation (R2 = 0.93) was found between their raw LD50 values. Potential virulence factors in B. cenocepacia K56-2 were identified using a high-throughput screen against single duckweed plants. In addition to the previously characterized antifungal compound (AFC) cluster genes, several uncharacterized genes were discovered including a novel lysR regulator, a histidine biosynthesis gene hisG, and a gene located near the gene encoding the recently characterized virulence factor SuhBBc. Finally, to demonstrate the utility of this model in therapeutic applications, duckweed was rescued from Bcc infection by treating with bacteriophage at 6-h intervals. It was observed that phage application became ineffective at a timepoint that coincided with a sharp increase in bacterial invasion of plant tissue. These results indicate that common duckweed can serve as an effective infection model for the investigation of bacterial virulence factors and therapeutic strategies to combat them.
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Within-host evolution of Burkholderia pseudomallei over a twelve-year chronic carriage infection. mBio 2013; 4:mBio.00388-13. [PMID: 23860767 PMCID: PMC3735121 DOI: 10.1128/mbio.00388-13] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Burkholderia pseudomallei causes the potentially fatal disease melioidosis. It is generally accepted that B. pseudomallei is a noncommensal bacterium and that any culture-positive clinical specimen denotes disease requiring treatment. Over a 23-year study of melioidosis cases in Darwin, Australia, just one patient from 707 survivors has developed persistent asymptomatic B. pseudomallei carriage. To better understand the mechanisms behind this unique scenario, we performed whole-genome analysis of two strains isolated 139 months apart. During this period, B. pseudomallei underwent several adaptive changes. Of 23 point mutations, 78% were nonsynonymous and 43% were predicted to be deleterious to gene function, demonstrating a strong propensity for positive selection. Notably, a nonsense mutation inactivated the universal stress response sigma factor RpoS, with pleiotropic implications. The genome underwent substantial reduction, with four deletions in chromosome 2 resulting in the loss of 221 genes. The deleted loci included genes involved in secondary metabolism, environmental survival, and pathogenesis. Of 14 indels, 11 occurred in coding regions and 9 resulted in frameshift mutations that dramatically affected predicted gene products. Disproportionately, four indels affected lipopolysaccharide biosynthesis and modification. Finally, we identified a frameshift mutation in both P314 isolates within wcbR, an important component of the capsular polysaccharide I locus, suggesting virulence attenuation early in infection. Our study illustrates a unique clinical case that contrasts a high-consequence infectious agent with a long-term commensal infection and provides further insights into bacterial evolution within the human host. Some bacterial pathogens establish long-term infections that are difficult or impossible to eradicate with current treatments. Rapid advances in genome sequencing technologies provide a powerful tool for understanding bacterial persistence within the human host. Burkholderia pseudomallei is considered a highly pathogenic bacterium because infection is commonly fatal. Here, we document within-host evolution of B. pseudomallei in a unique case of human infection with ongoing chronic carriage. Genomic comparison of isolates obtained 139 months (11.5 years) apart showed a strong signal of adaptation within the human host, including inactivation of virulence and immunogenic factors, and deletion of pathways involved in environmental survival. Two global regulatory genes were mutated in the 139-month isolate, indicating extensive regulatory changes favoring bacterial persistence. Our study provides insights into B. pseudomallei pathogenesis and, more broadly, identifies parallel evolutionary mechanisms that underlie chronic persistence of all bacterial pathogens.
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Subramoni S, Sokol PA. Quorum sensing systems influence Burkholderia cenocepacia virulence. Future Microbiol 2013; 7:1373-87. [PMID: 23231487 DOI: 10.2217/fmb.12.118] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Burkholderia cepacia complex strains communicate using N-acyl homoserine lactones and BDSF-dependent quorum sensing (QS) systems. Burkholderia cenocepacia QS systems include CepIR, CciIR, CepR2 and BDSF. Analysis of CepR, CciIR, CepR2 and RpfF (BDSF synthase) QS regulons revealed that these QS systems both independently regulate and coregulate many target genes, often in an opposing manner. The role of QS and several QS-regulated genes in virulence has been determined using vertebrate, invertebrate and plant infection models. Virulence phenotypes are strain and model dependent, suggesting that different QS-regulated genes are important depending on the strain and type of infection. QS inhibitors in combination with antibiotics can reduce biofilm formation and virulence in infection models.
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Affiliation(s)
- Sujatha Subramoni
- Department of Microbiology, Immunology & Infectious Diseases, Faculty of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta T2N 4N1, Canada
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The unexpected discovery of a novel low-oxygen-activated locus for the anoxic persistence of Burkholderia cenocepacia. ISME JOURNAL 2013; 7:1568-81. [PMID: 23486248 PMCID: PMC3721108 DOI: 10.1038/ismej.2013.36] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Revised: 01/25/2013] [Accepted: 01/28/2013] [Indexed: 12/11/2022]
Abstract
Burkholderia cenocepacia is a Gram-negative aerobic bacterium that belongs to a group of opportunistic pathogens displaying diverse environmental and pathogenic lifestyles. B. cenocepacia is known for its ability to cause lung infections in people with cystic fibrosis and it possesses a large 8 Mb multireplicon genome encoding a wide array of pathogenicity and fitness genes. Transcriptomic profiling across nine growth conditions was performed to identify the global gene expression changes made when B. cenocepacia changes niches from an environmental lifestyle to infection. In comparison to exponential growth, the results demonstrated that B. cenocepacia changes expression of over one-quarter of its genome during conditions of growth arrest, stationary phase and surprisingly, under reduced oxygen concentrations (6% instead of 20.9% normal atmospheric conditions). Multiple virulence factors are upregulated during these growth arrest conditions. A unique discovery from the comparative expression analysis was the identification of a distinct, co-regulated 50-gene cluster that was significantly upregulated during growth under low oxygen conditions. This gene cluster was designated the low-oxygen-activated (lxa) locus and encodes six universal stress proteins and proteins predicted to be involved in metabolism, transport, electron transfer and regulation. Deletion of the lxa locus resulted in B. cenocepacia mutants with aerobic growth deficiencies in minimal medium and compromised viability after prolonged incubation in the absence of oxygen. In summary, transcriptomic profiling of B. cenocepacia revealed an unexpected ability of aerobic Burkholderia to persist in the absence of oxygen and identified the novel lxa locus as key determinant of this important ecophysiological trait.
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Bragonzi A, Farulla I, Paroni M, Twomey KB, Pirone L, Lorè NI, Bianconi I, Dalmastri C, Ryan RP, Bevivino A. Modelling co-infection of the cystic fibrosis lung by Pseudomonas aeruginosa and Burkholderia cenocepacia reveals influences on biofilm formation and host response. PLoS One 2012; 7:e52330. [PMID: 23284990 PMCID: PMC3528780 DOI: 10.1371/journal.pone.0052330] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Accepted: 11/12/2012] [Indexed: 02/07/2023] Open
Abstract
The Gram-negative bacteria Pseudomonas aeruginosa and Burkholderia cenocepacia are opportunistic human pathogens that are responsible for severe nosocomial infections in immunocompromised patients and those suffering from cystic fibrosis (CF). These two bacteria have been shown to form biofilms in the airways of CF patients that make such infections more difficult to treat. Only recently have scientists begun to appreciate the complicated interplay between microorganisms during polymicrobial infection of the CF airway and the implications they may have for disease prognosis and response to therapy. To gain insight into the possible role that interaction between strains of P. aeruginosa and B. cenocepacia may play during infection, we characterised co-inoculations of in vivo and in vitro infection models. Co-inoculations were examined in an in vitro biofilm model and in a murine model of chronic infection. Assessment of biofilm formation showed that B. cenocepacia positively influenced P. aeruginosa biofilm development by increasing biomass. Interestingly, co-infection experiments in the mouse model revealed that P. aeruginosa did not change its ability to establish chronic infection in the presence of B. cenocepacia but co-infection did appear to increase host inflammatory response. Taken together, these results indicate that the co-infection of P. aeruginosa and B. cenocepacia leads to increased biofilm formation and increased host inflammatory response in the mouse model of chronic infection. These observations suggest that alteration of bacterial behavior due to interspecies interactions may be important for disease progression and persistent infection.
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Affiliation(s)
- Alessandra Bragonzi
- Division of Immunology, Transplantation and Infectious Diseases, Infections and Cystic Fibrosis Unit, San Raffaele Scientific Institute, Milan, Italy
| | - Ilaria Farulla
- Technical Unit for Sustainable Development and Innovation of Agro-Industrial System, ENEA Casaccia Research Centre, Rome, Italy
| | - Moira Paroni
- Division of Immunology, Transplantation and Infectious Diseases, Infections and Cystic Fibrosis Unit, San Raffaele Scientific Institute, Milan, Italy
| | - Kate B. Twomey
- Department of Microbiology, BioSciences Institute, University College Cork, Cork, Ireland
| | - Luisa Pirone
- Technical Unit for Sustainable Development and Innovation of Agro-Industrial System, ENEA Casaccia Research Centre, Rome, Italy
| | - Nicola Ivan Lorè
- Division of Immunology, Transplantation and Infectious Diseases, Infections and Cystic Fibrosis Unit, San Raffaele Scientific Institute, Milan, Italy
| | - Irene Bianconi
- Division of Immunology, Transplantation and Infectious Diseases, Infections and Cystic Fibrosis Unit, San Raffaele Scientific Institute, Milan, Italy
| | - Claudia Dalmastri
- Technical Unit for Sustainable Development and Innovation of Agro-Industrial System, ENEA Casaccia Research Centre, Rome, Italy
| | - Robert P. Ryan
- Department of Microbiology, BioSciences Institute, University College Cork, Cork, Ireland
| | - Annamaria Bevivino
- Technical Unit for Sustainable Development and Innovation of Agro-Industrial System, ENEA Casaccia Research Centre, Rome, Italy
- * E-mail:
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