Luis Máiz

Diagnóstico y tratamiento de las bronquiectasias

Bronchiectasis is the end result of several different diseases that share principles of management. The clinical course usually involves chronic bronchial infection and inflammation, which are associated with progression. The cause of bronchiectasis should always be investigated, particularly when it can be treated. We recommend evaluating etiology, symptoms, bronchial colonization and infection, respiratory function, inflammation, structural damage, nutritional status, and quality of life in order to assess severity and to monitor clinical course. Care should be supervised by specialized units, at least in cases of chronic bronchial infection, recurrent exacerbations, or when there is a cause that is likely to respond to treatment. Improving symptoms and halting progression are the goals of management, which is based on treatment of the underlying cause and of acute or chronic infections and on the drainage of secretions. Complications that arise must also be treated. Antibiotic prescription is guided by how well infection is being controlled, and this is indicated by the color of sputum and a reduction in the number of exacerbations. We recommend inhaled antibiotics in cases of chronic bronchial infection that does not respond to oral antibiotics, when these cause side effects, or when the cause is Pseudomonas species or other bacteria resistant to oral antibiotics. Inhaled administration is also advisable to treat initial colonization by Pseudomonas species.

Nontuberculous Mycobacteria in Patients with Cystic Fibrosis

The prevalence and clinical implications of colonization with nontuberculous mycobacteria were prospectively studied in 37 patients who had cystic fibrosis. Sputum samples were cultured on Coletsos and Löwenstein-Jensen selective media after decontamination with sodium hydroxide and oxalic acid. Oxalic acid-decontaminated fractions were also cultured in selective liquid medium. Nontuberculous mycobacteria were isolated from 6 patients (16.1%). Mycobacterium chelonae and Mycobacterium avium-intracellulare complex were the most common species. Three patients with positive results of culture had at least 1 positive result by acid-fast smear. Oxalic acid decontamination and culture in liquid medium had the lowest contamination rate (6.7%). Colonization with nontuberculous mycobacteria was associated with humoral response to mycobacteria (immunoglobulin G titers against antigen A60) in patients with samples that tested positive by acid-fast smear. An improvement in pulmonary function was observed in 2 patients after they received a course of antimycobacterial therapy. Screening for nontuberculous mycobacteria in patients with cystic fibrosis will contribute to understanding the relevance of these pathogens with regard to deterioration of pulmonary function in patients with cystic fibrosis.

Diagnosis and Treatment of Bronchiectasis

Bronchiectasis is the end result of several different diseases that share principles of management. The clinical course usually involves chronic bronchial infection and inflammation, which are associated with progression. The cause of bronchiectasis should always be investigated, particularly when it can be treated. We recommend evaluating etiology, symptoms, bronchial colonization and infection, respiratory function, inflammation, structural damage, nutritional status, and quality of life in order to assess severity and to monitor clinical course. Care should be supervised by specialized units, at least when there is a history of chronic bronchial infection, recurrent exacerbations, or a cause that is likely to respond to treatment. Improving symptoms and halting progression are the goals of management, which is based on treatment of the underlying cause and of acute or chronic infections and on the drainage of secretions. Complications that arise must also be treated. Antibiotic prescription is guided by monitoring how well infection is being controlled, and this is indicated by the color of sputum and a reduction in the number of exacerbations. We recommend inhaled antibiotics when bronchial infection is chronic and does not respond to oral antibiotics or when these cause side effects, or when the cause is Pseudomonas species or other bacteria resistant to oral antibiotics. Inhaled administration is also advisable to treat initial colonization by Pseudomonas species.

Improvement of digestive health and reduction in proteobacterial populations in the gut microbiota of cystic fibrosis patients using a Lactobacillus reuteri probiotic preparation: a double blind prospective study.

BACKGROUND Although scientific knowledge about the benefits of probiotic use in cystis fibrosis (CF) is scarce, their expectative is promising. The aim of this work was to analyze the effect of a Lactobacillus reuteri probiotic preparation versus placebo in CF patients. METHODS A prospective, double blind, crossover and with placebo study was carried out in 30 CF patients from two Spanish hospitals. Patients were randomized in Group A (6 months of probiotic followed by 6 months of placebo) and Group B (6 months of placebo followed by 6 months of probiotic). GIQLI (gastrointestinal) and SF-12 (general) health tests were performed after probiotic and placebo intakes. Fat absorption coefficient, calprotectin, and inflammatory interleukin quantification were determined in fecal samples. Total fecal DNA was obtained and metagenomic 454-pyrosequencing was applied to analyze the microbiome composition. STATA v12 MP software was used for statistical analyses. RESULTS Statistically significant improvement in the gastrointestinal health and decrease of the calprotectin levels were demonstrated in patients after probiotic exposure, in comparison with placebo. All CF subjects reported good tolerance to L. reuteri without secondary effects. Metagenomic analysis showed an important dysbiosis in CF gut microbiota associated with a high concentration of Proteobacteria. Probiotic intake was followed by a reduction in the total bacterial density, mostly due to a considerable reduction in the γ-Proteobacteria phylum; and an important increase of the microbial diversity with a higher representation of Firmicutes. CONCLUSIONS Probiotics might ameliorate the dysbiosis of CF gut microbiota, characterized by a high density of Proteobacterial organisms. L. reuteri significantly decrease intestinal inflammation and increase digestive comfort.

High prevalence in cystic fibrosis patients of multiresistant hospital-acquired methicillin-resistant Staphylococcus aureus ST228-SCCmecI capable of biofilm formation

OBJECTIVES Although methicillin-resistant Staphylococcus aureus (MRSA) is increasingly recognized in cystic fibrosis (CF) patients, it has not been sufficiently studied in large series. We analysed all MRSA isolates recovered from respiratory secretions of patients attending our CF unit (1994-2006). METHODS Antibiotic susceptibilities were determined using both planktonic and sessile bacteria as inocula. Genetic relationships were determined by PFGE and multilocus sequence typing (MLST). SCCmec type and the presence of the pvl gene were also investigated. RESULTS A total of 93 MRSA isolates (1-20 isolates per patient) were recovered from 18 of 77 CF patients with positive staphylococcal culture. Mean prevalence (4.4%) increased (P < 0.001) over time. All isolates were susceptible to linezolid, quinupristin/dalfopristin and co-trimoxazole but presented high resistance rates to amikacin (90%), gentamicin (85%), levofloxacin (81%) and erythromycin (69%). Except for macrolides and gentamicin, isolates were less susceptible growing in biofilms than in planktonic cultures. Fifteen different PFGE patterns were found, one of them consistently recovered for 6 years in the same patient. Identical clones were detected in several unrelated patients. MLST demonstrated that the international ST228 was the most frequent (67%) clone. The pvl gene was negative in all isolates and the SCCmec corresponded to types I (97%) and IV (3%). Strong mutators were not detected, but a considerable number were considered weak mutators. CONCLUSIONS Distinct microbiological and molecular features were detected among CF-MRSA isolates, probably due to adaptation to specific conditions in CF patients. Prevalence of MRSA increased among these patients, most of them colonized with a multiresistant biofilm-forming clone belonging to ST228-SSCmecI, suggesting cross-transmission or a common source.

MALDI-TOF MS improves routine identification of non-fermenting Gram negative isolates from cystic fibrosis patients.

Identification of non-fermenting Gram-negative bacteria (NFGNB) from cystic fibrosis (CF) patients is often limited. A collection of stored NFGNB isolates (n=182) recovered from CF patients over a 15 year period was examined. The routinely reported identification during this period was compared with that obtained by MALDI-TOF MS. Isolates giving discrepant identification at the genus level were further analyzed by 16S rDNA sequencing. The MALDI-TOF MS system identified 94% of the isolates, including Burkholderia cepacia and Pandoraea spp. isolates, the latter previously misidentified as other NFGNB by conventional microbiological methods. Lack of identification by MALDI-TOF MS was associated with the absence of entries in the database.

Population Structure, Antimicrobial Resistance, and Mutation Frequencies of Streptococcus pneumoniae Isolates from Cystic Fibrosis Patients

ABSTRACT Forty-eight Streptococcus pneumoniae isolates recovered from sputum samples from 26 cystic fibrosis (CF) patients attending our CF unit (1995 to 2003) were studied. Mean yearly incidence of isolation was 5.5%, and all were strains recovered from young patients (≤12 years). The isolation was linked to clinical exacerbation in 35% of the cases, but only 27% of these were not accompanied by other CF pathogens. Fifty percent of the patients presented with two to four isolates over the studied period. Pulsed-field gel electrophoresis-SmaI digestion revealed a high heterogeneity (32 pulsotypes among 48 isolates) and the persistence over a 6-month period of a single clone (clone A) in two patients. This clone, presenting a varied multiresistance phenotype, was identified as the Spain23F-1 clone and was also recognized in six other patients, including two out of nine patients from the CF unit of Sant Joan de Dèu Hospital, Barcelona, Spain. In our isolates, 16 different serotypes were recognized, the most frequent being 23F (33.3%), 19F (18.8%), 6A (6.2%), and 6B (6.2%). High overall resistance rates were observed: to penicillin, 73%; to cefotaxime, 33%; to erythromycin, 42%; to tetracycline, 58%; to chloramphenicol, 48%; and to trimethoprim-sulfamethoxazole, 67%. Resistance to fluoroquinolones was not detected. Multiresistance was a common feature (60%). The percentage of S. pneumoniae strains with increased frequencies of mutation to rifampin resistance (≥7.5 × 10−8) was significantly higher (P = 0.02) in CF (60%) than among non-CF (37%) isolates in the same institution (M. I. Morosini et al., Antimicrob. Agents Chemother. 47:1464-1467, 2003). Even though a clear association with acute exacerbations could not be observed, long-term clonal persistence and variability, high frequency of antibiotic resistance, and hypermutability indicate the plasticity for adaptation of S. pneumoniae to the CF lung environment.

Inhaled antibiotics for the treatment of chronic bronchopulmonary Pseudomonas aeruginosa infection in cystic fibrosis: systematic review of randomised controlled trials

Introduction: Inhaled antibiotics are probably the safest and most effective therapy for Pseudomonas aeruginosa chronic lung infection in cystic fibrosis (CF) patients. Areas covered: To summarise the available evidence, a systematic review of the three currently available inhaled antibiotics (aztreonam lysine (AZLI), colistin (COL) and tobramycin (TOB)) was performed. The three AZLI placebo-controlled studies showed that the improvements in FEV1 and mean sputum P. aeruginosa density were statistically significant better than with placebo. The two COL placebo-controlled studies involved few patients but showed that COL was better than placebo in terms of maintenance of some pulmonary function parameters. The tobramycin inhalation solution (TIS) and tobramycin inhalation powder studies showed that the efficacy of both formulations was similar but significantly better than placebo. In the comparative studies, TIS showed more efficacy than COL solution, colistin inhalation powder showed non-inferiority to TIS and AZLI was superior to TIS. Expert opinion: Placebo-controlled and comparative clinical trials have shown that clinical evidence of inhaled antibiotics is very different. The choice of treatment for each individual CF patient must be based on the features of the drug (clinical evidence on efficacy and safety), the inhalation system and the patient characteristics. Development of new inhaled antibiotics will allow new end points of efficacy and therapy regimens to be assessed.

In vitro prevention of Pseudomonas aeruginosa early biofilm formation with antibiotics used in cystic fibrosis patients

The ability of antibiotics used in bronchopulmonary infections in cystic fibrosis (CF) patients to prevent Pseudomonas aeruginosa early biofilm formation was studied using a biofilm microtitre assay with 57 non-mucoid P. aeruginosa isolates (44 first colonisers and 13 recovered during the initial intermittent colonisation stage) obtained from 35 CF patients. Minimum biofilm inhibitory concentrations (BICs) of levofloxacin, ciprofloxacin, imipenem, ceftazidime, tobramycin, colistin and azithromycin were determined by placing a peg lid with a formed biofilm onto microplates containing antibiotics. A modification of this protocol consisting of antibiotic challenge during biofilm formation was implemented in order to determine the biofilm prevention concentration (BPC), i.e. the minimum concentration able to prevent biofilm formation. The lowest BPCs were for fluoroquinolones, tobramycin and colistin and the highest for ceftazidime and imipenem. The former antibiotics had BPCs identical to or only slightly higher than their minimum inhibitory concentrations (MICs) determined by standard Clinical and Laboratory Standards Institute (CLSI) microdilution and were also active on formed biofilms as reflected by their low BIC values. In contrast, ceftazidime and imipenem were less effective for prevention of biofilm formation and on formed biofilms. In conclusion, the new BPC parameter determined in non-mucoid P. aeruginosa isolates recovered during early colonisation stages in CF patients supports early aggressive antimicrobial treatment guidelines in first P. aeruginosa-colonised CF patients.

Patógenos multirresistentes en la fibrosis quística

La infección pulmonar es una de las causas más importantes de morbilidad y mortalidad en el paciente con fibrosis quística (FQ). La evolución en el tiempo, su calidad de vida y sus expectativas de supervivencia son proporcionales al número anual de exacerbaciones y a la carga de microorganismos en las secreciones respiratorias1,2. El particular nicho ecológico del pulmón en los pacientes con FQ, el incremento de la edad y los tratamientos antimicrobianos prolongados determinan que, con elevada frecuencia, se encuentren microorganismos multirresistentes que hacen aún más difícil el control de la progresión de la colonización y el deterioro de la función pulmonar. En este sentido, es importante definir y conocer los patrones de sensibilidad de los microorganismos que habitualmente colonizan la vía aérea del paciente con FQ, los aspectos clínicos relacionados con la colonización por patógenos multirresistentes y las opciones terapéuticas específicas para cada situación. El diagnóstico microbiológico y la detección de estos patógenos en las muestras respiratorias son imprescindibles para un correcto control y seguimiento de estos pacientes. En abril de 2001 la Fundación Sira Carrasco para la ayuda a la FQ reunió en Madrid a pediatras, neumólogos y microbiólogos para dar a conocer, entre otros, un documento que sirviese de reflexión y guía de información sobre estos patógenos. La importancia de los microorganismos multirresistentes en la FQ se había constatado en una encuesta realizada con anterioridad3, en la que el 86% de los representantes de las diferentes unidades de FQ de España manifestaron que la multirresistencia era un problema acuciante, que podría condicionar el futuro de los tratamientos antimicrobianos y la calidad de vida de estos pacientes. En el presente trabajo se recogen los aspectos más sobresalientes de dicho documento, analizando el concepto de multirresistencia, su aplicación particular a los patógenos en la FQ, los factores que determinan su aparición, su repercusión clínica y algunos aspectos relacionados con el seguimiento microbiológico de los pacientes con aislamientos multirresistentes. Concepto de multirresistencia