[Chronic bronchial infection: the problem of Pseudomonas aeruginosa].
ABSTRACT Pathogenic bronchopulmonary colonizations and the exacerbations produced are among the most important causes of reduced pulmonary function in patients with bronchiectasis. The most frequent pathogens in these patients are Haemophilus influenzae and Pseudomonas aeruginosa. Lesions are produced by the local inflammatory process and the vicious circle developed by antigen stimulation, the release of inflammatory mediators, the presence of neutrophils, the increase of bacterial inoculum and the release of bacterial exoproducts. P. aeruginosa has been demonstrated to affect the patients with bronchiectasis and poorest quality of life and to colonize those with the poorest pulmonary function and the highest number of antimicrobial treatments. In bronchiectasis, as in chronic obstructive pulmonary disease (COPD) or cystic fibrosis, P. aeruginosa is able to colonize the respiratory mucosa chronically. Due to the ecological niche occupied by P. aeruginosa and the multitude of cycles with antimicrobial agents to which these patients are subjected, the development of antimicrobial resistance is highly likely, encouraged by the high proportion of hypermutation variants in existence. Likewise, P. aeruginosa naturally grows in the form of biofilms on the mucosal surface, greatly contributing to its persistence. Antimicrobial treatment in patients with bronchiectasis and P. aeruginosa colonization should be based on antimicrobial agents, alone or in combination, that do not lose activity when acting on biofilms.
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ABSTRACT: Background: Cystic Fibrosis (CF) is a severe genetic disorder that is common among the Caucasian population. Bacterial respiratory infections are the main cause of morbidity and mortality in CF patients. Pseudomonas aeruginosa is the main pathogen of lower airways (LAW) decline. Method: To understand chronic broncho-pulmonary colonization, a systematic review is conducted. The aim of our article is to identify the pathways of contamination in the upper aero-digestive tract. Results: A large number of articles report that P. aeruginosa is established first at nasopharyngeal sites. The vast majority of authors agree that the upper aero-digestive tract is the first location of colonization by P. aeruginosa and its presence appears to be predictive of subsequent broncho-pulmonary colonization. Conclusion: This review supports the possible involvement of the nasal and paranasal sinuses and oral cavity as means of contamination.Journal of cystic fibrosis: official journal of the European Cystic Fibrosis Society 06/2014; 14(1). DOI:10.1016/j.jcf.2014.04.008 · 3.82 Impact Factor
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ABSTRACT: Cystic fibrosis (CF) is the most frequent genetic lethal disease in Caucasian population. Lung destruction is the principal cause of death by chronic P. aeruginosa colonization. There is a high prevalence of oropharyngeal anaerobic bacteria in sputum of CF patients. This study was carried out due to the lack of results comparing subgingival periodontal pathogenic bacteria between CF oral cavity and lungs in relation with P. aeruginosa presence. Our first goal was to detect P. aeruginosa in oral and sputum samples by culture and molecular methods, and to determine clonality of isolates. In addition, subgingival periodontal anaerobic bacteria were searched for in sputum. A cross sectional pilot case-control study was conducted in the CF Reference Center in Roscoff, France. Ten ΔF508 homozygous CF patients were enrolled (5 chronically colonized (CC) and 5 not colonized (NC)). P.aeruginosa was detected in saliva, sputum and subgingival plaque samples by real-time PCR (qPCR). Subsequently, periodontal bacteria were also detected and quantified in subgingival plaque and sputum samples by qPCR. In CC patients P. aeruginosa was recovered in saliva and subgingival plaque samples. Sixteen P. aeruginosa strains were isolated in saliva and sputum in this group and compared by Pulsed Field Gel Electrophoresis (PFGE). Subgingival periodontal anaerobic bacteria were found in sputum samples. A lower diversity of these species was recovered in the CC patients compared to NC patients. Presence of the same P.aeruginosa clonal types in saliva and sputum samples underlines that the oral cavity is a possible reservoir for lung infection. Copyright © 2015, American Society for Microbiology. All Rights Reserved.Journal of clinical microbiology 04/2015; 53(6). DOI:10.1128/JCM.00368-15 · 4.23 Impact Factor
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ABSTRACT: Ceragenins, synthetic mimics of endogenous antibacterial peptides, are promising candidate antimicrobial agents. However, in some settings their strong bactericidal activity is associated with toxicity towards host cells. To modulate ceragenin CSA-13 antibacterial activity and biocompatibility, CSA-13-coated magnetic nanoparticles (MNP-CSA-13) were synthesized. Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to characterize MNP-CSA-13 physicochemical properties. Bactericidal action and ability of these new compounds to prevent Pseudomonas. aeruginosa biofilm formation were assessed using a bacteria killing assay and crystal violet staining, respectively. Release of hemoglobin from human red blood cells was measured to evaluate MNP-CSA-13 hemolytic activity. In addition, we used surface activity measurements to monitor CSA-13 release from the MNP shell. Zeta potentials of P. aeruginosa cells and MNP-CSA-13 were determined to assess the interactions between the bacteria and nanoparticles. Morphology of P. aeruginosa subjected to MNP-CSA-13 treatment was evaluated using atomic force microscopy (AFM) to determine structural changes indicative of bactericidal activity. Our studies revealed that the MNP-CSA-13 nanosystem is stable and may be used as a pH control system to release CSA-13. MNP-CSA-13 exhibits strong antibacterial activity, and the ability to prevent bacteria biofilm formation in different body fluids. Additionally, a significant decrease in CSA-13 hemolytic activity was observed when the molecule was immobilized on the nanoparticle surface. Our results demonstrate that CSA-13 retains bactericidal activity when immobilized on a MNP while biocompatibility increases when CSA-13 is covalently attached to the nanoparticle.Journal of Nanobiotechnology 05/2015; 13(1):32. DOI:10.1186/s12951-015-0093-5 · 4.08 Impact Factor