Molecular conservation within LES9F and PS21 Liverpool epidemic strain (LES) markers in wild-type clinical Pseudomonas aeruginosa isolated from the sputum of adult patients with cystic fibrosis

ABSTRACT In cystic fibrosis, a recessive genetic disease caused by defects in the cystic fibrosis conductance regulator (CFTR), the main cause of death is lung infection and inflammation. Nutritional deficits have been proposed to contribute to the excessive host inflammatory response in both humans and Cftr-knockout mice. Cftr-knockout mice and gut-corrected Cftr-knockout mice expressing human CFTR primarily in the gut were challenged with Pseudomonas aeruginosa-laden agarose beads; they responded similarly with respect to bronchoalveolar lavage cell counts and levels of the acute-phase cytokines tumor necrosis factor alpha, interleukin-1β (IL-1β), and IL-6. Wild-type mice fed the liquid diet used to prevent intestinal obstruction in Cftr-knockout mice had inflammatory responses to P. aeruginosa-laden agarose beads similar to those of wild-type mice fed an enriched solid diet, so dietary effects are unlikely to account for differences between wild-type mice and mice with cystic fibrosis. Finally, since cystic fibrosis patients and Cftr-knockout mice have an imbalance in fatty acids (significantly lower-than-normal levels of docosahexaenoic acid), the effects of specific supplementation with docosahexaenoic acid of wild-type and Cftr-knockout mice on their inflammatory responses to P. aeruginosa-laden agarose beads were tested. There were no significant differences (P = 0.35) in cumulative survival rates between Cftr-knockout mice and wild-type mice provided with either the liquid diet Peptamen or Peptamen containing docosahexaenoic acid. In conclusion, diet and docosahexaenoic acid imbalances alone are unlikely to explain the differences in the host response to lung infections with mucoid P. aeruginosa between mice with cystic fibrosis and their wild-type counterparts.

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Persistency of Pseudomonas aeruginosa in sputum cultures and clinical outcomes in adult patients with cystic fibrosis

European Journal of Clinical Microbiology & Infectious Diseases ◽

10.1007/s10096-011-1483-8 ◽

2011 ◽

Vol 31 (7) ◽

pp. 1603-1610 ◽

Cited By ~ 12

Author(s):

A. Burkett ◽

K. L. Vandemheen ◽

T. Giesbrecht-Lewis ◽

K. Ramotar ◽

W. Ferris ◽

...

Keyword(s):

Cystic Fibrosis ◽

Pseudomonas Aeruginosa ◽

Clinical Outcomes ◽

Adult Patients

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154* Assessing the role of lysogenic bacteriophages in a cystic fibrosis epidemic strain of Pseudomonas aeruginosa

Journal of Cystic Fibrosis ◽

10.1016/s1569-1993(11)60170-7 ◽

2011 ◽

Vol 10 ◽

pp. S39

Author(s):

J.L. Fothergill ◽

A.-A. Lemieux ◽

C.E. James ◽

I. Kukavica-Ibrulj ◽

G. Filion ◽

...

Keyword(s):

Cystic Fibrosis ◽

Pseudomonas Aeruginosa ◽

Epidemic Strain

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Environmental contamination with an epidemic strain of Pseudomonas aeruginosa in a Liverpool cystic fibrosis centre, and study of its survival on dry surfaces

Journal of Hospital Infection ◽

10.1016/j.jhin.2004.09.018 ◽

2005 ◽

Vol 59 (2) ◽

pp. 102-107 ◽

Cited By ~ 87

Author(s):

S. Panagea ◽

C. Winstanley ◽

M.J. Walshaw ◽

M.J. Ledson ◽

C.A. Hart

Keyword(s):

Cystic Fibrosis ◽

Pseudomonas Aeruginosa ◽

Environmental Contamination ◽

Epidemic Strain ◽

Cystic Fibrosis Centre

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Pseudomonas aeruginosa Rugose Small-Colony Variants Have Adaptations That Likely Promote Persistence in the Cystic Fibrosis Lung

Journal of Bacteriology ◽

10.1128/jb.00119-09 ◽

2009 ◽

Vol 191 (11) ◽

pp. 3492-3503 ◽

Cited By ~ 227

Author(s):

Melissa Starkey ◽

Jason H. Hickman ◽

Luyan Ma ◽

Niu Zhang ◽

Susan De Long ◽

...

Keyword(s):

Cystic Fibrosis ◽

Pseudomonas Aeruginosa ◽

Intracellular Signaling ◽

Tricarboxylic Acid Cycle ◽

Gene Clusters ◽

Wild Type ◽

Phenotypic Analysis ◽

Small Colony Variants ◽

Airway Infections ◽

Small Colony

ABSTRACT Pseudomonas aeruginosa is recognized for its ability to colonize diverse habitats, ranging from soil to immunocompromised people. The formation of surface-associated communities called biofilms is one factor thought to enhance colonization and persistence in these diverse environments. Another factor is the ability of P. aeruginosa to diversify genetically, generating phenotypically distinct subpopulations. One manifestation of diversification is the appearance of colony morphology variants on solid medium. Both laboratory biofilm growth and chronic cystic fibrosis (CF) airway infections produce rugose small-colony variants (RSCVs) characterized by wrinkled, small colonies and an elevated capacity to form biofilms. Previous reports vary on the characteristics attributable to RSCVs. Here we report a detailed comparison of clonally related wild-type and RSCV strains isolated from both CF sputum and laboratory biofilm cultures. The clinical RSCV had many characteristics in common with biofilm RSCVs. Transcriptional profiling and Biolog phenotypic analysis revealed that RSCVs display increased expression of the pel and psl polysaccharide gene clusters, decreased expression of motility functions, and a defect in growth on some amino acid and tricarboxylic acid cycle intermediates as sole carbon sources. RSCVs also elicited a reduced chemokine response from polarized airway epithelium cells compared to wild-type strains. A common feature of all RSCVs analyzed in this study is increased levels of the intracellular signaling molecule cyclic di-GMP (c-di-GMP). To assess the global transcriptional effects of elevated c-di-GMP levels, we engineered an RSCV strain that had elevated c-di-GMP levels but did not autoaggregate. Our results showed that about 50 genes are differentially expressed in response to elevated intracellular c-di-GMP levels. Among these genes are the pel and psl genes, which are upregulated, and flagellum and pilus genes, which are downregulated. RSCV traits such as increased exopolysaccharide production leading to antibiotic tolerance, altered metabolism, and reduced immunogenicity may contribute to increased persistence in biofilms and in the airways of CF lungs.

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Sera from Adult Patients with Cystic Fibrosis Contain Antibodies to Pseudomonas aeruginosa Type III Apparatus

Infection and Immunity ◽

10.1128/iai.69.2.1185-1188.2001 ◽

2001 ◽

Vol 69 (2) ◽

pp. 1185-1188 ◽

Cited By ~ 32

Author(s):

Joel Moss ◽

Mary E. Ehrmantraut ◽

Bruce D. Banwart ◽

Dara W. Frank ◽

Joseph T. Barbieri

Keyword(s):

Cystic Fibrosis ◽

Immune Response ◽

Pseudomonas Aeruginosa ◽

Adult Patients ◽

Eukaryotic Cells ◽

Type Iii

ABSTRACT Expression of type III proteins of Pseudomonas aeruginosa in patients with cystic fibrosis (CF) was investigated by measuring the immune response against components of the type III pathway. Twenty-three of the 33 sera contained antibodies against PcrV, a protein involved in translocation of type III cytotoxins into eukaryotic cells, and 11 of 33 had antibodies against ExoS, while most CF sera contained antibodies against PopB and PopD, components of the type III apparatus. These data indicate that P. aeruginosacommonly expresses components of the type III translocation apparatus in adult CF patients.

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Lung arginase expression and activity is increased in cystic fibrosis mouse models

Journal of Applied Physiology ◽

10.1152/japplphysiol.00167.2014 ◽

2014 ◽

Vol 117 (3) ◽

pp. 284-288 ◽

Cited By ~ 9

Author(s):

Thomas Jaecklin ◽

Julia Duerr ◽

Hailu Huang ◽

Mahroukh Rafii ◽

Christine E. Bear ◽

...

Keyword(s):

Cystic Fibrosis ◽

Pseudomonas Aeruginosa ◽

Mouse Models ◽

Arginase Activity ◽

Mouse Lung ◽

Wild Type ◽

Arginase 1 ◽

Isolated Lung ◽

Deficient Mice ◽

Expression And Activity

The activity of arginase is increased in airway secretions of patients with cystic fibrosis (CF). Downstream products of arginase activity may contribute to CF lung disease. We hypothesized that pulmonary arginase expression and activity would be increased in mouse models of CF and disproportionally increased in CF mice with Pseudomonas aeruginosa pneumonia. Expression of arginase isoforms in lung tissue was quantified with reverse transcriptase-PCR in naive cystic fibrosis transmembrane conductance regulator ( Cftr)-deficient mice and β-epithelial sodium channel-overexpressing [β-ENaC-transgenic (Tg)] mice. An isolated lung stable isotope perfusion model was used to measure arginase activity in Cftr-deficient mice before and after intratracheal instillation of Pseudomonas aeruginosa. The expression of arginase-2 in lung was increased in adult Cftr-deficient animals and in newborn β-ENaC-Tg. Arginase-1 lung expression was normal in Cftr-deficient and in newborn β-ENaC-Tg mice, but was increased in β-ENaC-Tg mice at age 1, 3, and 6 wk. Arginase activity was significantly higher in lung (5.0 ± 0.7 vs. 3.2 ± 0.3 nmol·−1·h−1, P = 0.016) and airways (204.6 ± 49.8 vs. 79.3 ± 17.2 nmol·−1·h−1, P = 0.045) of naive Cftr-deficient mice compared with sex-matched wild-type littermate controls. Infection with Pseudomonas aeruginosa resulted in a far greater increase in lung arginase activity in Cftr-deficient mice (10-fold) than in wild-type controls (6-fold) ( P = 0.01). This is the first ex vivo characterization of arginase expression and activity in CF mouse lung and airways. Our data show that pulmonary arginase expression and activity is increased in CF mice, especially with Pseudomonas aeruginosa infections.

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