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Kaur H, Pandey S, Jat KR, Lodha R, Kabra SK. Predictors of mortality in children with cystic fibrosis in India. Pediatr Pulmonol 2022; 57:648-654. [PMID: 34826368 DOI: 10.1002/ppul.25766] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 10/11/2021] [Accepted: 10/12/2021] [Indexed: 11/10/2022]
Abstract
BACKGROUND There is a lack of studies on cystic fibrosis (CF) outcomes in children from developing countries like India. Identifying risk factors for mortality may help identify the high-risk group and plan policy management of such patients. We aimed to determine the factors associated with mortality among Indian children with CF. METHODS In this retrospective study, we extracted demography, clinical features, laboratory and outcome data from medical records of children with CF. Bivariate and multivariate analysis was performed to identify variables associated with mortality. RESULTS We enrolled 178 children, and there were 32 (18.0%) deaths. Median (IQR) z-score for body mass index (BMI) at last follow up was -1.5 (-2.7, -0.2) and -2.5 (-4.0, -1.6), p-value 0.039, in survived and deceased group respectively. Mean (SD) of % predicted of FEV1/FVC and FEV1 25-75 at the time of diagnosis in survived versus diseased group was 94.7 (24.1) versus 81.5 (19.1), p-value 0.063 and 56.1 (38.9) versus 45.7 (29.9), p-value 0.347, respectively. Significant factors associated with mortality included history of neonatal complications; hazard ratio (HR): 8.5 (95% confidence interval [CI]: 3.0-23.9, p < 0.001), low Z-scores for BMI at the time of diagnosis; HR: 7.1 (95% CI: 2.3-22.0, p < 0.001), FEV1/FVC at the time of diagnosis; HR: 5.1 (95% CI: 1.65-15.4, p < 0.004), and FEV1 25-75; HR: 3.6 (95% CI: 1.1-11.8, p = 0.03). CONCLUSIONS Factors associated with increased mortality risk included neonatal complications, low BMI, and lower pulmonary function test results. Low BMI and low PFT indices can be improved upon by timely treatment of respiratory infections, better nutrition, early diagnosis, and treatment. A newborn screening program may help in early diagnosis and identification of the neonatal problem of CF.
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Affiliation(s)
- Hardeep Kaur
- Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, New Delhi, India
| | - Shivam Pandey
- Department of Biostatistics, All India Institute of Medical Sciences, New Delhi, New Delhi, India
| | - Kana R Jat
- Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, New Delhi, India
| | - Rakesh Lodha
- Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, New Delhi, India
| | - S K Kabra
- Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, New Delhi, India
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Perault AI, Chandler CE, Rasko DA, Ernst RK, Wolfgang MC, Cotter PA. Host Adaptation Predisposes Pseudomonas aeruginosa to Type VI Secretion System-Mediated Predation by the Burkholderia cepacia Complex. Cell Host Microbe 2020; 28:534-547.e3. [PMID: 32755549 PMCID: PMC7554260 DOI: 10.1016/j.chom.2020.06.019] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 06/05/2020] [Accepted: 06/24/2020] [Indexed: 12/14/2022]
Abstract
Pseudomonas aeruginosa and Burkholderia cepacia complex (Bcc) species are opportunistic lung pathogens of cystic fibrosis (CF) patients. While P. aeruginosa can initiate long-term infections in younger CF patients, Bcc infections only arise in teenagers and adults. Both P. aeruginosa and Bcc use type VI secretion systems (T6SSs) to mediate interbacterial competition. Here, we show P. aeruginosa isolates from teenage and adult CF patients, but not those from young CF patients, are outcompeted by the epidemic Bcc isolate Burkholderia cenocepacia strain AU1054 in a T6SS-dependent manner. The genomes of susceptible P. aeruginosa isolates harbor T6SS-abrogating mutations, the repair of which, in some cases, rendered the isolates resistant. Moreover, seven of eight Bcc strains outcompeted P. aeruginosa strains isolated from the same patients. Our findings suggest certain mutations that arise as P. aeruginosa adapts to the CF lung abrogate T6SS activity, making P. aeruginosa and its human host susceptible to potentially fatal Bcc superinfection.
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Affiliation(s)
- Andrew I Perault
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Courtney E Chandler
- Department of Microbial Pathogenesis, University of Maryland, Baltimore, Baltimore, MD 21201, USA
| | - David A Rasko
- Institute for Genome Sciences, University of Maryland, Baltimore, Baltimore, MD 21201, USA; Department of Microbiology and Immunology, University of Maryland, Baltimore, Baltimore, MD 21201, USA
| | - Robert K Ernst
- Department of Microbial Pathogenesis, University of Maryland, Baltimore, Baltimore, MD 21201, USA
| | - Matthew C Wolfgang
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Marsio Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Peggy A Cotter
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
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3
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Narayanaswamy VP, Duncan AP, LiPuma JJ, Wiesmann WP, Baker SM, Townsend SM. In Vitro Activity of a Novel Glycopolymer against Biofilms of Burkholderia cepacia Complex Cystic Fibrosis Clinical Isolates. Antimicrob Agents Chemother 2019; 63:e00498-19. [PMID: 30910901 PMCID: PMC6535541 DOI: 10.1128/aac.00498-19] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 03/11/2019] [Indexed: 12/12/2022] Open
Abstract
Burkholderia cepacia complex (Bcc) lung infections in cystic fibrosis (CF) patients are often associated with a steady decline in lung function and death. The formation of biofilms and inherent multidrug resistance are virulence factors associated with Bcc infection and contribute to increased risk of mortality in CF patients. New therapeutic strategies targeting bacterial biofilms are anticipated to enhance antibiotic penetration and facilitate resolution of infection. Poly (acetyl, arginyl) glucosamine (PAAG) is a cationic glycopolymer therapeutic being developed to directly target biofilm integrity. In this study, 13 isolates from 7 species were examined, including Burkholderia multivorans, Burkholderia cenocepacia, Burkholderia gladioli, Burkholderia dolosa, Burkholderia vietnamiensis, and B. cepacia These isolates were selected for their resistance to standard clinical antibiotics and their ability to form biofilms in vitro Biofilm biomass was quantitated using static tissue culture plate (TCP) biofilm methods and a minimum biofilm eradication concentration (MBEC) assay. Confocal laser scanning microscopy (CLSM) visualized biofilm removal by PAAG during treatment. Both TCP and MBEC methods demonstrated a significant dose-dependent relationship with regard to biofilm removal by 50 to 200 μg/ml PAAG following a 1-h treatment (P < 0.01). A significant reduction in biofilm thickness was observed following a 10-min treatment of Bcc biofilms with PAAG compared to that with vehicle control (P < 0.001) in TCP, MBEC, and CLSM analyses. PAAG also rapidly permeabilizes bacteria within the first 10 min of treatment. Glycopolymers, such as PAAG, are a new class of large-molecule therapeutics that support the treatment of recalcitrant Bcc biofilm.
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Affiliation(s)
| | | | - John J LiPuma
- University of Michigan, Department of Pediatrics and Communicable Diseases, Ann Arbor, Michigan, USA
| | | | | | - Stacy M Townsend
- Townsend Bio-Pharm Consulting, Rancho Cucamonga, California, USA
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da Costa Ferreira Leite C, Folescu TW, de Cássia Firmida M, Cohen RWF, Leão RS, de Freitas FAD, Albano RM, da Costa CH, Marques EA. Monitoring clinical and microbiological evolution of a cystic fibrosis patient over 26 years: experience of a Brazilian CF Centre. BMC Pulm Med 2017; 17:100. [PMID: 28705217 PMCID: PMC5513036 DOI: 10.1186/s12890-017-0442-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Accepted: 06/29/2017] [Indexed: 12/03/2022] Open
Abstract
Background Burkholderia cepacia complex is a group of opportunistic pathogens in cystic fibrosis (CF) patients believed to be associated with poor prognosis and patient-to-patient transmissibility. Little is known about clinical outcomes after B. vietnamiensis chronic colonization/infection. Case presentation A 33 yo male patient had diagnosis of CF by 7 yo, after recurrent pneumonia during infancy and lobectomy (left upper lobe) at 6 yo. Burkholderia cepacia complex (Bcc) was first isolated by 13 yo, and the patient fulfilled the criteria for chronic colonization by 15 yo. In the following 16 years (1997–2013), there was intermittent isolation of P. aeruginosa and continuous isolation of Bcc, identified as B. vietnamiensis. There was clinical and laboratorial stability for 16 years with annual rate of decline in forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) of 1.61 and 1.35%, respectively. From 2013 to 2015, there was significant clinical and lung function deterioration: annual rate of decline in FEV1 and FVC was 3 and 4.1%, respectively while body mass index decreased from 18.1 to 17.1. Episodes of hemoptysis and respiratory exacerbations (with hospital admissions) became more frequent. CF related diabetes was diagnosed (fasting glycemia: 116 mg/dL, oral glucose tolerance test: 305 mg/dL). Because of the severity of the disease in the last years, in addition to traditional microbiological surveillance, microbiome analysis by next generation sequencing (NGS) was performed on respiratory secretions. The NGS showed that 97% of the sequencing data were attributed to genus Burkholderia. Conclusions We report the case of a 33-year-old male CF patient known to have chronic infection with B. vietnamiensis who remained clinically stable for 16 years and presented recent clinical and laboratorial deterioration. Microbiome analysis of respiratory secretions was performed in 3 samples collected in 2014–2015. Clinical deterioration overlapped with cystic fibrosis-related diabetes and microbiome composition revealed no significant differences when compared microbiome results to culture dependent methods.
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Affiliation(s)
- Cassiana da Costa Ferreira Leite
- Departamento de Microbiologia, Imunologia e Parasitologia, Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Tania Wrobel Folescu
- Instituto Nacional de Saúde da Mulher da Criança e do Adolescente Fernandes Figueira, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Mônica de Cássia Firmida
- Departamento de Doenças do Tórax, Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Renata Wrobel Folescu Cohen
- Instituto Nacional de Saúde da Mulher da Criança e do Adolescente Fernandes Figueira, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Robson Souza Leão
- Departamento de Microbiologia, Imunologia e Parasitologia, Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Flávia Alvim Dutra de Freitas
- Departamento de Bioquímica, Instituto de Biologia Roberto Alcântara Gomes, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Rodolpho Mattos Albano
- Departamento de Bioquímica, Instituto de Biologia Roberto Alcântara Gomes, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Claudia Henrique da Costa
- Departamento de Doenças do Tórax, Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Elizabeth Andrade Marques
- Departamento de Microbiologia, Imunologia e Parasitologia, Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil. .,Departamento de Microbiologia, Imunologia e Parasitologia, Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro, Brazil Av. 28 de setembro 87, Fundos, Terceiro andar- Vila Isabel, Rio de Janeiro, RJ, Brazil.
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5
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Novel glycopolymer sensitizes Burkholderia cepacia complex isolates from cystic fibrosis patients to tobramycin and meropenem. PLoS One 2017; 12:e0179776. [PMID: 28662114 PMCID: PMC5491046 DOI: 10.1371/journal.pone.0179776] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 06/02/2017] [Indexed: 11/19/2022] Open
Abstract
Burkholderia cepacia complex (Bcc) infection, associated with cystic fibrosis (CF) is intrinsically multidrug resistant to antibiotic treatment making eradication from the CF lung virtually impossible. Infection with Bcc leads to a rapid decline in lung function and is often a contraindication for lung transplant, significantly influencing morbidity and mortality associated with CF disease. Standard treatment frequently involves antibiotic combination therapy. However, no formal strategy has been adopted in clinical practice to guide successful eradication. A new class of direct-acting, large molecule polycationic glycopolymers, derivatives of a natural polysaccharide poly-N-acetyl-glucosamine (PAAG), are in development as an alternative to traditional antibiotic strategies. During treatment, PAAG rapidly targets the anionic structural composition of bacterial outer membranes. PAAG was observed to permeabilize bacterial membranes upon contact to facilitate potentiation of antibiotic activity. Three-dimensional checkerboard synergy analyses were used to test the susceptibility of eight Bcc strains (seven CF clinical isolates) to antibiotic combinations with PAAG or ceftazidime. Potentiation of tobramycin and meropenem activity was observed in combination with 8-128 μg/mL PAAG. Treatment with PAAG reduced the minimum inhibitory concentration (MIC) of tobramycin and meropenem below their clinical sensitivity breakpoints (≤4 μg/mL), demonstrating the ability of PAAG to sensitize antibiotic resistant Bcc clinical isolates. Fractional inhibitory concentration (FIC) calculations showed PAAG was able to significantly potentiate antibacterial synergy with these antibiotics toward all Bcc species tested. These preliminary studies suggest PAAG facilitates a broad synergistic activity that may result in more positive therapeutic outcomes and supports further development of safe, polycationic glycopolymers for inhaled combination antibiotic therapy, particularly for CF-associated Bcc infections.
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Schaefers MM, Liao TL, Boisvert NM, Roux D, Yoder-Himes D, Priebe GP. An Oxygen-Sensing Two-Component System in the Burkholderia cepacia Complex Regulates Biofilm, Intracellular Invasion, and Pathogenicity. PLoS Pathog 2017; 13:e1006116. [PMID: 28046077 PMCID: PMC5234846 DOI: 10.1371/journal.ppat.1006116] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 01/13/2017] [Accepted: 12/09/2016] [Indexed: 12/22/2022] Open
Abstract
Burkholderia dolosa is a member of the Burkholderia cepacia complex (BCC), which is a group of bacteria that cause chronic lung infection in patients with cystic fibrosis (CF) and can be associated with outbreaks carrying high morbidity and mortality. While investigating the genomic diversity of B. dolosa strains collected from an outbreak among CF patients, we previously identified fixL as a gene showing signs of strong positive selection. This gene has homology to fixL of the rhizobial FixL/FixJ two-component system. The goals of this study were to determine the functions of FixLJ and their role in virulence in B. dolosa. We generated a fixLJ deletion mutant and complemented controls in B. dolosa strain AU0158. Using a fixK-lacZ reporter we found that FixLJ was activated in low oxygen in multiple BCC species. In a murine pneumonia model, the B. dolosa fixLJ deletion mutant was cleared faster from the lungs and spleen than wild-type B. dolosa strain AU0158 at 7 days post infection. Interestingly, the fixLJ deletion mutant made more biofilm, albeit with altered structure, but was less motile than strain AU0158. Using RNA-seq with in vitro grown bacteria, we found ~11% of the genome was differentially expressed in the fixLJ deletion mutant relative to strain AU0158. Multiple flagella-associated genes were down-regulated in the fixLJ deletion mutant, so we also evaluated virulence of a fliC deletion mutant, which lacks a flagellum. We saw no difference in the ability of the fliC deletion mutant to persist in the murine model relative to strain AU0158, suggesting factors other than flagella caused the phenotype of decreased persistence. We found the fixLJ deletion mutant to be less invasive in human lung epithelial and macrophage-like cells. In conclusion, B. dolosa fixLJ is a global regulator that controls biofilm formation, motility, intracellular invasion/persistence, and virulence. In people with cystic fibrosis (CF), infection with bacteria in the Burkholderia cepacia complex (BCC) is often associated with clinical deterioration. In a whole-genome sequencing study of the BCC species B. dolosa, we previously identified the fixL gene of the FixL/FixJ two-component system called FixLJ to be under strong positive selective pressure during chronic infection. In this study we show that low oxygen levels activate FixLJ, and that a mutant of B. dolosa in which the fixLJ genes are deleted is less able to persist in the lungs and spread to the spleen in a lung infection model in mice. The fixLJ deletion mutant has defective motility and intracellular survival within epithelial cells and macrophage cell lines. However, a flagella mutant is fully infectious, suggesting that low motility is not responsible for the fixLJ deletion mutant’s inability to persist within the host. Analysis of global RNA expression shows that the fixLJ system regulates many genes, indicating that multiple pathways likely contribute to the low virulence of the fixLJ deletion mutant. In conclusion, B. dolosa FixLJ compose an oxygen sensor that regulates the ability of the bacteria to survive inside host cells.
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Affiliation(s)
- Matthew M. Schaefers
- Division of Critical Care Medicine, Department of Anesthesiology, Perioperative and Pain Medicine, Boston Children’s Hospital, Boston, Massachusetts, United States of America
- Department of Anaesthesia, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
| | - Tiffany L. Liao
- Division of Critical Care Medicine, Department of Anesthesiology, Perioperative and Pain Medicine, Boston Children’s Hospital, Boston, Massachusetts, United States of America
| | - Nicole M. Boisvert
- Division of Critical Care Medicine, Department of Anesthesiology, Perioperative and Pain Medicine, Boston Children’s Hospital, Boston, Massachusetts, United States of America
| | - Damien Roux
- IAME, UMR 1137, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France; Service de Réanimation médico-chirurgicale, Hôpital Louis Mourier, AP-HP, Colombes, France
| | - Deborah Yoder-Himes
- Department of Biology, University of Louisville, Louisville, Kentucky, United States of America
| | - Gregory P. Priebe
- Division of Critical Care Medicine, Department of Anesthesiology, Perioperative and Pain Medicine, Boston Children’s Hospital, Boston, Massachusetts, United States of America
- Department of Anaesthesia, Harvard Medical School, Boston, Massachusetts, United States of America
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7
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Folescu TW, da Costa CH, Cohen RWF, da Conceição Neto OC, Albano RM, Marques EA. Burkholderia cepacia complex: clinical course in cystic fibrosis patients. BMC Pulm Med 2015; 15:158. [PMID: 26642758 PMCID: PMC4672471 DOI: 10.1186/s12890-015-0148-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 11/20/2015] [Indexed: 11/10/2022] Open
Abstract
Background Pulmonary deterioration after B.cepacia complex (BCC) colonization has a heterogeneous pattern. The aim was to investigate the clinical outcome of BCC colonization in CF patients chronically colonized with P. aeruginosa. Methods CF patients chronically colonized with P. aeruginosa were divided into three groups: intermittent (I), chronic (II) and no colonization (III) with BCC. Body mass index (BMI) percentile and spirometric parameters were analyzed at three different times in each group. Results Fifty-six patients chronically colonized with P. aeruginosa were included. Of these, 27 also had evidence of BCC colonization (13 intermittent and 14 chronic). BMI percentile was significantly lower among patients chronically colonized by both P. aeruginosa and BCC. Mean values of FEV1 and FVC % were also significantly lower in these patients, both at the time of chronic BCC colonization and 24 months forward. Conclusions Chronic BCC colonization is associated with significant loss of lung function. Lower BMI might be a risk factor for chronic BCC colonization, preceding these events.
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Affiliation(s)
- Tania Wrobel Folescu
- Department of Pediatric Pulmonology, Instituto Fernandes Figueira (Fundação Oswaldo Cruz, Ministério da Saúde), Av. Rui Barbosa, 716, 2nd floor, Flamengo, Zip Code: 22250-020, Rio de Janeiro, RJ, Brazil.
| | - Claudia Henrique da Costa
- Department of Pulmonology, Universidade do Estado do Rio de Janeiro/UERJ, Rio de Janeiro, RJ, Brazil.
| | - Renata Wrobel Folescu Cohen
- Department of Pediatric Pulmonology, Instituto Fernandes Figueira (Fundação Oswaldo Cruz, Ministério da Saúde), Av. Rui Barbosa, 716, 2nd floor, Flamengo, Zip Code: 22250-020, Rio de Janeiro, RJ, Brazil.
| | | | - Rodolpho Mattos Albano
- Department of Biochemistry, Universidade do Estado do Rio de Janeiro/UERJ, Rio de Janeiro, RJ, Brazil.
| | - Elizabeth Andrade Marques
- Department of Microbiology, Universidade do Estado do Rio de Janeiro/UERJ, Rio de Janeiro, RJ, Brazil.
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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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9
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Abdulrahman BA, Khweek AA, Akhter A, Caution K, Tazi M, Hassan H, Zhang Y, Rowland PD, Malhotra S, Aeffner F, Davis IC, Valvano MA, Amer AO. Depletion of the ubiquitin-binding adaptor molecule SQSTM1/p62 from macrophages harboring cftr ΔF508 mutation improves the delivery of Burkholderia cenocepacia to the autophagic machinery. J Biol Chem 2012; 288:2049-58. [PMID: 23148214 DOI: 10.1074/jbc.m112.411728] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Cystic fibrosis is the most common inherited lethal disease in Caucasians. It is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR), of which the cftr ΔF508 mutation is the most common. ΔF508 macrophages are intrinsically defective in autophagy because of the sequestration of essential autophagy molecules within unprocessed CFTR aggregates. Defective autophagy allows Burkholderia cenocepacia (B. cepacia) to survive and replicate in ΔF508 macrophages. Infection by B. cepacia poses a great risk to cystic fibrosis patients because it causes accelerated lung inflammation and, in some cases, a lethal necrotizing pneumonia. Autophagy is a cell survival mechanism whereby an autophagosome engulfs non-functional organelles and delivers them to the lysosome for degradation. The ubiquitin binding adaptor protein SQSTM1/p62 is required for the delivery of several ubiquitinated cargos to the autophagosome. In WT macrophages, p62 depletion and overexpression lead to increased and decreased bacterial intracellular survival, respectively. In contrast, depletion of p62 in ΔF508 macrophages results in decreased bacterial survival, whereas overexpression of p62 leads to increased B. cepacia intracellular growth. Interestingly, the depletion of p62 from ΔF508 macrophages results in the release of the autophagy molecule beclin1 (BECN1) from the mutant CFTR aggregates and allows its redistribution and recruitment to the B. cepacia vacuole, mediating the acquisition of the autophagy marker LC3 and bacterial clearance via autophagy. These data demonstrate that p62 differentially dictates the fate of B. cepacia infection in WT and ΔF508 macrophages.
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Affiliation(s)
- Basant A Abdulrahman
- Department of Microbial Infection and Immunity, Ohio State University, Columbus, Ohio 43210, USA
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10
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Abdulrahman BA, Khweek AA, Akhter A, Caution K, Kotrange S, Abdelaziz DHA, Newland C, Rosales-Reyes R, Kopp B, McCoy K, Montione R, Schlesinger LS, Gavrilin MA, Wewers MD, Valvano MA, Amer AO. Autophagy stimulation by rapamycin suppresses lung inflammation and infection by Burkholderia cenocepacia in a model of cystic fibrosis. Autophagy 2011; 7:1359-70. [PMID: 21997369 DOI: 10.4161/auto.7.11.17660] [Citation(s) in RCA: 150] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Cystic fibrosis (CF) is the most common inherited lethal disease of Caucasians which results in multi organ dysfunction. However, 85% of the deaths are due to pulmonary infections. Infection by Burkholderia cenocepacia (B. cepacia) is a particularly lethal threat to CF patients because it causes severe and persistent lung inflammation and is resistant to nearly all available antibiotics. In CFTR ΔF508 mouse macrophages, B. cepacia persists in vacuoles that do not fuse with the lysosomes and mediates increased production of IL-1β. It is believed that intracellular bacterial survival contributes to the persistence of the bacterium. Here we show for the first time that in wild-type macrophages but not in ΔF508 macrophages, many B. cepacia reside in autophagosomes that fuse with lysosomes at later stages of infection. Accordingly, association and intracellular survival of B. cepacia are higher in CFTR-ΔF508 (ΔF508) macrophages than in WT macrophages. An autophagosome is a compartment that engulfs non-functional organelles and parts of the cytoplasm then delivers them to the lysosome for degradation to produce nutrients during periods of starvation or stress. Furthermore, we show that B. cepacia downregulates autophagy genes in WT and ΔF508 macrophages. However, autophagy dysfunction is more pronounced in ΔF508 macrophages since they already have compromised autophagy activity. We demonstrate that the autophagy-stimulating agent, rapamycin markedly decreases B. cepacia infection in vitro by enhancing the clearance of B. cepacia via induced autophagy. In vivo, Rapamycin decreases bacterial burden in the lungs of CF mice and drastically reduces signs of lung inflammation. Together, our studies reveal that if efficiently activated, autophagy can control B. cepacia infection and ameliorate the associated inflammation. Therefore, autophagy is a novel target for new drug development for CF patients to control B. cepacia infection and accompanying inflammation.
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Affiliation(s)
- Basant A Abdulrahman
- Center for Microbial Interface Biology, Department of Microbial Infection, Ohio State University, Columbus, OH, USA
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11
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Cooper VS, Carlson WA, LiPuma JJ. Susceptibility of Caenorhabditis elegans to Burkholderia infection depends on prior diet and secreted bacterial attractants. PLoS One 2009; 4:e7961. [PMID: 19956737 PMCID: PMC2776534 DOI: 10.1371/journal.pone.0007961] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2009] [Accepted: 10/17/2009] [Indexed: 12/05/2022] Open
Abstract
The nematode Caenorhabditis elegans may be killed by certain pathogenic bacteria and thus is a model organism for studying interactions between bacteria and animal hosts. However, growing nematodes on prey bacteria may influence their susceptibility to potential pathogens. A method of axenic nematode culture was developed to isolate and quantify interactions between C. elegans and potentially pathogenic strains of the Burkholderia cepacia complex. Studying these dynamics in liquid solution rather than on agar surfaces minimized nematode avoidance behavior and resolved more differences among isolates. Most isolates of B. cenocepacia, B. ambifaria and B. cepacia caused 60–80% mortality of nematodes after 7 days, whereas isolates of B. multivorans caused less mortality (<25%) and supported nematode reproduction. However, some B. cenocepacia isolates recovered from chronic infections were much less virulent (5–28% mortality). As predicted, prior diet altered the outcome of interactions between nematodes and bacteria. When given the choice between Burkholderia and E. coli as prey on agar, axenically raised nematodes initially preferred most lethal Burkholderia isolates to E. coli as a food source, but this was not the case for nematodes fed E. coli, which avoided toxic Burkholderia. This food preference was associated with the cell-free supernatant and thus secreted compounds likely mediated bacterial-nematode interactions. This model, which isolates interactions between bacteria and nematodes from the effects of prior feeding, demonstrates that bacteria can influence nematode behavior and their susceptibility to pathogens.
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Affiliation(s)
- Vaughn S. Cooper
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, New Hampshire, United States of America
- * E-mail:
| | - Wendy A. Carlson
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, New Hampshire, United States of America
| | - John J. LiPuma
- Department of Pediatrics and Communicable Diseases, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
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Reid DW, Anderson GJ, Lamont IL. Role of lung iron in determining the bacterial and host struggle in cystic fibrosis. Am J Physiol Lung Cell Mol Physiol 2009; 297:L795-802. [DOI: 10.1152/ajplung.00132.2009] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Cystic fibrosis (CF) is the most common lethal genetic disorder in Caucasian populations. It is a multiorgan system disease that affects the lungs, gastrointestinal tract, liver, and pancreas. The majority of morbidity and mortality in CF relates to chronic airway infection with a variety of bacterial species, commencing in very early infancy, which results in lung destruction and ultimately organ failure ( 41 , 43 ). This review focuses on iron homeostasis in the CF lung and its role in determining the success and chronicity of Pseudomonas aeruginosa infection. There have been previous excellent reviews regarding iron metabolism in the lower respiratory tract and mechanisms of P. aeruginosa iron acquisition, and we direct readers to these articles for further background reading ( 31 , 53 , 58 , 77 , 96 ). In this review, we have brought the “two sides of the coin” together to provide a holistic overview of the relationship between host and bacterial iron homeostasis and put this information into the context of current understanding on infection in the CF lung.
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Affiliation(s)
- D. W. Reid
- Menzies Research Institute, Hobart, Tasmania
| | - G. J. Anderson
- Iron Metabolism Unit, Queensland Institute of Medical Research, Brisbane, Australia; and
| | - I. L. Lamont
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
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13
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El-Laboudi A, Etherington C, Whitaker P, Clifton I, Conway S, Denton M, Peckham D. Acute Burkholderia cenocepacia pyomyositis in a patient with cystic fibrosis. J Cyst Fibros 2009; 8:273-5. [DOI: 10.1016/j.jcf.2009.04.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2009] [Revised: 04/14/2009] [Accepted: 04/26/2009] [Indexed: 10/20/2022]
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Abstract
In summary, there is a significant interplay between the pulmonary manifestations and nutritional status of CF patients. The advances in CF clinical care in the past 2 decades are mainly attributed to anti-infective therapy as well as aggressive nutritional management. Currently, there are multiple therapeutic agents that are in clinical trial that target either the underlying CFTR defect or the downstream effects of CFTR. The broad spectrum of therapeutic agents being studied as well as the advances in therapies that target the underlying CFTR defect are exciting, making it likely that at least one of the treatments will make a major difference in how we will treat CF in the future.
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Affiliation(s)
- Reshma Amin
- Division of Respiratory Medicine, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, ON, M5G 1X8, Canada
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Kutty PK, Moody B, Gullion JS, Zervos M, Ajluni M, Washburn R, Sanderson R, Kainer MA, Powell TA, Clarke CF, Powell RJ, Pascoe N, Shams A, LiPuma JJ, Jensen B, Noble-Wang J, Arduino MJ, McDonald LC. Multistate Outbreak of Burkholderia cenocepacia Colonization and Infection Associated With the Use of Intrinsically Contaminated Alcohol-Free Mouthwash. Chest 2007; 132:1825-31. [DOI: 10.1378/chest.07-1545] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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Courtney JM, Bradley J, Mccaughan J, O'Connor TM, Shortt C, Bredin CP, Bradbury I, Elborn JS. Predictors of mortality in adults with cystic fibrosis. Pediatr Pulmonol 2007; 42:525-32. [PMID: 17469153 DOI: 10.1002/ppul.20619] [Citation(s) in RCA: 123] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Assessment of prognostic indicators in patients with cystic fibrosis (CF) is important. The study's aim was to assess the relative contribution of gender, genetics and microbiology on survival in adults with CF. Adult patients were studied from 1995 to 2005 and data collected included FEV(1) (%predicted), body mass index (BMI), genetics, and microbiology. Data was available on 183 patients in 1995. Forty-five patients died in the subsequent 10 years. Patients who died during the study had lower mean (SD) FEV(1) %predicted in 1995 when compared to those remaining alive, 41.5 (15.2)% versus 69.8 (23.2)% predicted, respectively, P<0.001 and they had lower mean (SD) BMI in 1995, 19.2 (3.3) kg/m(2) in comparison to those remaining alive, 20.7 (3.4) kg/m(2), P=0.008. The proportion of patients infected with Pseudomonas aeruginosa and Burkholderia cepacia complex was higher in the group who died during the study compared to those remaining alive, odds ratio 20.9 P<0.0001 and 7.1 P<0.0001, respectively. The presence of the Delta F508 homozygous mutation did not alter survival, P=0.3. Patients infected with either P.aeruginosa or B.cepacia complex had reduced survival compared to those without infection, P=0.01 and P<0.0001, respectively. FEV(1)% (P<0.0001), infection with P.aeruginosa (P=0.005) or B.cepacia complex (P=0.03) were the only significant predictors of mortality. This study demonstrates adults who died were more likely to have worse lung function and be infected with either P.aeruginosa or B.cepacia complex. FEV(1)% and infection with P.aeruginosa or B.cepacia complex were the most significant predictors of survival in adults with CF.
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Affiliation(s)
- J M Courtney
- Adult Cystic Fibrosis Unit, Belfast City Hospital, Belfast, Northern Ireland, Ireland.
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Affiliation(s)
- J S Elborn
- Respiratory Medicine Group, Queens' University of Belfast, Belfast, N. Ireland.
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Courtney JM, Dunbar KEA, McDowell A, Moore JE, Warke TJ, Stevenson M, Elborn JS. Clinical outcome of Burkholderia cepacia complex infection in cystic fibrosis adults. J Cyst Fibros 2004; 3:93-8. [PMID: 15463892 DOI: 10.1016/j.jcf.2004.01.005] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2003] [Accepted: 01/28/2004] [Indexed: 11/20/2022]
Abstract
BACKGROUND The Burkholderia cepacia complex (BCC) is one of the most important groups of organisms infecting cystic fibrosis (CF) patients. The aim of the study was to examine how infection with BCC affects clinical outcome. METHODS Nineteen CF adults infected with BCC and 19 controls infected with Pseudomonas aeruginosa were studied over a 4-year period. The best forced expiratory volume in 1 s (FEV(1)) and body mass index (BMI) for each year were recorded and annual rate of decline calculated. RESULTS The BCC infected group displayed a significantly greater reduction of FEV(1) and BMI compared to the P. aeruginosa infected group (p=0.001 and p=0.009, respectively). Sixteen patients infected with a single Burkholderia cenocepacia strain had a significantly greater rate of FEV(1) decline compared to those infected with Burkholderia multivorans (n=3) or P. aeruginosa (p=0.01 and p<0.0001, respectively). The rate of BMI decline was significantly greater in patients infected with B. cenocepacia compared to those with P. aeruginosa (p=0.007), but not significantly different in those with B. multivorans (p=0.29). CONCLUSION BCC infection is associated with an accelerated decline in pulmonary function and BMI. Infection with a single B. cenocepacia strain was associated with a more rapid decline in lung function than those infected with either B. multivorans or P. aeruginosa.
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Affiliation(s)
- J M Courtney
- Adult Cystic Fibrosis Centre, Belfast City Hospital, Lisburn Road, Belfast BT9 7AB, North Ireland, UK
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Abstract
Since international recommendations for lung transplant recipients were made in 1998, newer tools for predicting mortality in patients who have end-stage lung disease have been investigated. This article reviews studies for predicting mortality in obstructive, restrictive, pulmonary vascular, and suppurative/bronchiectatic lung disease. Newer considerations for alternative treatments, postoperative risks, and contraindications are also examined. The article aims to provide more accurate data for selecting patients who will benefit from lung transplantation.
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Affiliation(s)
- Andrew D Yu
- Division of Pulmonary and Critical Care Medicine, Loyola University Medical Center, 2160 S. First Avenue, Building 54, Room 131A, Maywood, IL 60153, USA
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Häussler S, Lehmann C, Breselge C, Rohde M, Classen M, Tümmler B, Vandamme P, Steinmetz I. Fatal outcome of lung transplantation in cystic fibrosis patients due to small-colony variants of the Burkholderia cepacia complex. Eur J Clin Microbiol Infect Dis 2003; 22:249-53. [PMID: 12687415 DOI: 10.1007/s10096-003-0901-y] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The aim of this study was to investigate the possible role of small-colony variant morphotypes of Burkholderia cepacia-like organisms in infectious complications in cystic fibrosis patients following lung transplantation. Respiratory tract specimens from 470 cystic fibrosis patients were screened over a 22-month period for Burkholderia cepacia-like organisms. Nineteen patients were positive for these organisms, eight of whom harboured small-colony-variant morphotypes. Three patients underwent bilateral lung transplantation during the study, two of whom harboured small-colony variants in addition to clonally identical wildtypes of Burkholderia multivorans and Burkholderia cepacia genomovar III prior to lung transplantation. Both patients developed fatal systemic infections post transplantation due to small-colony variants. In vitro testing revealed that small-colony variants exhibited increased serum resistance in comparison to wildtypes. The results of this study indicate that diagnostic efforts should be undertaken to carefully identify small-colony variants of Burkholderia cepacia complex, since they might be an indicator of poor post-transplantation outcome in patients with cystic fibrosis.
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Affiliation(s)
- S Häussler
- Institut für Medizinische Mikrobiologie, Medizinische Hochschule Hannover, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany
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Abstract
Chronic endobronchial infection with shape Pseudomonas aeruginosa in patients with cystic fibrosis is associated with more serious disease and reduced survival. Methods for reducing or preventing chronic infection with P. aeruginosa involve rigorous infection control measures and avoidance of cross-infection, which may include segregation of clinics according to microbiological status. The strains of shape P. aeruginosa first isolated from the lungs of cystic fibrosis patients are generally of a non-mucoid phenotype and sensitive to antibiotic therapy. There is some evidence that early aggressive antibiotic treatment may delay chronic infection, improve lung function and improve survival. Further research is needed into the accurate diagnosis of early infection with shape P. aeruginosa, which is often intermittent. In addition, the optimal treatment of patients at first isolation and early colonisation needs to be researched, including choice of antibiotic(s) and route, dosage and duration of antibiotic therapy.
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Affiliation(s)
- Andrew Bush
- Imperial School of Medicine and Royal Brompton Hospital, London, UK.
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