La malaltia del legionari i l'aigua als hospitals

La legionel·losi nosocomial, o malaltia del legionari adquirida a l'hospital, és una afecció relacionada amb la presència del bacteri Legionella als sistemes de distribució d'aigua sanitària hospitalària. Aquest treball identifica l'existència d'una elevada variabilitat i estabilitat genètica dels patrons moleculars del bacteri analitzats en el sistema d'aigua de 7 hospitals

Functional Metagenomics of the Bronchial Microbiome in COPD

Altres ajuts: Sociedad Catalana de Neumología; Fundació Catalana de Neumología; Fundació Parc Tauli; Marató de TV3; Sociedad Española de Neumología y Cirugía Torácica; Fundación Menarini; Generalitat Valenciana (Spain) [Prometeo/2009/092] i Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES)The course of chronic obstructive pulmonary disease (COPD) is frequently aggravated by exacerbations, and changes in the composition and activity of the microbiome may be implicated in their appearance. The aim of this study was to analyse the composition and the gene content of the microbial community in bronchial secretions of COPD patients in both stability and exacerbation. Taxonomic data were obtained by 16S rRNA gene amplification and pyrosequencing, and metabolic information through shotgun metagenomics, using the Metagenomics RAST server (MG-RAST), and the PICRUSt (Phylogenetic Investigation of Communities by Reconstruction of Unobserved States) programme, which predict metagenomes from 16S data. Eight severe COPD patients provided good quality sputum samples, and no significant differences in the relative abundance of any phyla and genera were found between stability and exacerbation. Bacterial biodiversity (Chao1 and Shannon indexes) did not show statistical differences and beta-diversity analysis (Bray-Curtis dissimilarity index) showed a similar microbial composition in the two clinical situations. Four functional categories showed statistically significant differences with MG-RAST at KEGG level 2: in exacerbation, Cell growth and Death and Transport and Catabolism decreased in abundance [1.6 (0.2-2.3) vs 3.6 (3.3-6.9), p = 0.012; and 1.8 (0-3.3) vs 3.6 (1.8-5.1), p = 0.025 respectively], while Cancer and Carbohydrate Metabolism increased [0.8 (0-1.5) vs 0 (0-0.5), p = 0.043; and 7 (6.4-9) vs 5.9 (6.3-6.1), p = 0.012 respectively]. In conclusion, the bronchial microbiome as a whole is not significantly modified when exacerbation symptoms appear in severe COPD patients, but its functional metabolic capabilities show significant changes in several pathways

Environmental cultures and hospital-acquired Legionnaires' disease : a 5-year prospective study in 20 hospitals in Catalonia, Spain

Objective: To determine whether environmental cultures for Legionella increase the index of suspicion for legionnaires' disease (LD). Design: Five-year prospective study. Setting: Twenty hospitals in Catalonia, Spain. Methods: From 1994 to 1996, the potable water systems of 20 hospitals in Catalonia were tested for Legionella, Cases of hospital-acquired LD and availability of an "in-house" Legionella test in the previous 4 years were assessed. After the hospitals were informed of the results of their water cultures, a prospective 5-year-study was conducted focusing on the detection of new cases of nosocomial legionellosis and the availability and use of Legionella testing. Results: Before environmental cultures were started, only one hospital had conducted active surveillance of hospital-acquired pneumonia and used Legionella tests including Legionella urinary antigen in all pneumonia cases. Only one other hospital had used the latter test at all. In six hospitals, Legionella tests had been completely unavailable. Cases of nosocomial LD had been diagnosed in the previous 4 years in only two hospitals. During prospective surveillance, 12 hospitals (60%) used Legionella urinary antigen testing in house and 11 (55%) found cases of nosocomial legionellosis, representing 64.7% (11 of 17) of those with positive water cultures. Hospitals with negative water cultures did not find nosocomial LD. Conclusions: The environmental study increased the index of suspicion for nosocomial LD. The number of cases of nosocomial LD increased significantly during the prospective follow-up period, and most hospitals began using the Legionella urinary antigen test in their laboratories

Guia per a la prevenció i el control de la legionel·losi

Malaltia dels legionaris; Pneumònia; EpidemiologiaLegionnaires disease; EpidemiologyEnfermedad de los legionariosLa Guia per a la prevenció i el control de la legionel·losi actualitza la informació sobre la malaltia, integra la normativa vigent sobre el control de les instal·lacions relacionades amb la legionel·losi i aposta pel futur amb capítols relacionats amb la prevenció primària als hospitals o els mètodes de desinfecci

A global analysis of Y-chromosomal haplotype diversity for 23 STR loci

In a worldwide collaborative effort, 19,630 Y-chromosomes were sampled from 129 different populations in 51 countries. These chromosomes were typed for 23 short-tandem repeat (STR) loci (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS385ab, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS635, GATAH4, DYS481, DYS533, DYS549, DYS570, DYS576, and DYS643) and using the PowerPlex Y23 System (PPY23, Promega Corporation, Madison, WI). Locus-specific allelic spectra of these markers were determined and a consistently high level of allelic diversity was observed. A considerable number of null, duplicate and off-ladder alleles were revealed. Standard single-locus and haplotype-based parameters were calculated and compared between subsets of Y-STR markers established for forensic casework. The PPY23 marker set provides substantially stronger discriminatory power than other available kits but at the same time reveals the same general patterns of population structure as other marker sets. A strong correlation was observed between the number of Y-STRs included in a marker set and some of the forensic parameters under study. Interestingly a weak but consistent trend toward smaller genetic distances resulting from larger numbers of markers became apparent.Peer reviewe

Colonización citopatogenicidad y persistencia de Legionella spp. en agua sanitaria hospitalaria

La prevalencia ambiental de Legionella spp. en centros hospitalarios y la incidencia real de legionelosis nosocomial son datos por lo general mal conocidos o muy variables de unas áreas a otras. El primer paso para la identificación de la infección nosocomial por Legionella es demostrar la colonización del sistema de distribución hospitalaria para poder establecer un nexo epidemiológico. La comprensión de la ecología y las características de Legionella, a nivel de colonización, tipado, persistencia y virulencia, son esenciales para entender esta problemática y establecer las medidas de prevención.En el primer objetivo, se estudió la prevalencia y variabilidad genotípica de Legionella en los sistemas de distribución de agua sanitaria y refrigeración de 20 hospitales de Cataluña. L. pneumophila se aisló en 17 de los 20 hospitales estudiados en un 37% (73/196) de las muestras analizadas. El nivel de contaminación osciló entre 200 y 74.250 ufc/L en puntos de consumo, y de 200 a 55.500 ufc/L en puntos centrales. El 39,7 % de las muestras positivas estaban colonizadas por L. pneumophila sg. 1 y el resto por L. pneumophila sg. 2-14. El tipado molecular mediante electroforesis en campo pulsante (PFGE) permitió distinguir 25 patrones PFGE diferentes que no estaban compartidos entre los diferentes hospitales. En 10 hospitales se identificó un único patrón, en 6 hospitales se coexistían 2 patrones PFGE y en un hospital coexistían 3 patrones PFGE. Los resultados de este estudio fueron fundamentales para establecer la necesidad de cultivos ambientales en los hospitales en los decretos sobre prevención de legionelosis posteriores en España y Cataluña (RD 865/2003 i D352/2004). También destacó por la necesidad de implementar técnicas de diagnóstico específicas de legionelosis en caso de neumonía de adquisición intrahospitalaria para conocer la incidencia real que tiene cada centro sanitario.En el segundo objetivo, se intenta responder a la pregunta de si la virulencia de las cepas de L. pneumophila presentes en los circuitos de agua sanitaria de un centro sanitario influye en la aparición de casos clínicos en el centro. En este estudio se presentan datos de citopatogenicidad (CEPD50%) de 22 aislados de Legionella con diferente patrón PFGE y se determina su relación con el serogrupo 1, el número de patrones PFGE coexistentes en le mimo sistema de agua sanitaria y con la declaración de casos de legionelosis nosocomial. Todos los aislados eran capaces de infectar y crecer intracelularmente en cultivos de macrófagos produciendo un efecto citopático significativo. Se establecieron 5 grupos citopatogénicos según sus valores CEPD50%. Los aislados de L. pneumophila sg. 1 tenían una citopatogenicidad media más elevada (p=0.003) que los aislados L. pneumophila no-sg. 1. Además, se observaron tendencias de los aislados pertenecientes a los grupos más citopatogénicos (1 a 3) a pertenecer a aquellos hospitales con más de un patrón en los sistemas de distribución de agua (60 % vs. 17 %) y los hospitales que declaraban casos de legionelosis nosocomial (36,3 % vs. 16.6%).En el tercer objetivo se investigó la epidemiología molecular de aislados clínicos y ambientales de Legionella procedentes de 7 hospitales durante los años 1989 a 2006. El número de patrones PFGE de los aislados ambientales oscilaba de 1 a 9 según el hospital. La persistencia genotípica se observó en el 71% de los hospitales, e incluso durante 17 años en algunos hospitales, y se pudo establecer una relación entre los patrones PFGE de origen clínico y los de origen ambiental. Los aislados asociados con legionelosis nosocomial se correspondían a los aislados ambientales que persistían durante más tiempo en los sistemas de distribución de agua sanitaria.The environmental prevalence of Legionella spp. in hospitals and the incidence of the nosocomial legionelosis are unkonwn data, variable between different areas. Demonstration of water-system contamination is the first step in identifying nosocomial Legionella infection in a hospital. Understanding the ecology and characteristics of Legionella at level of colonization, typing, virulence and persistence are essential to understand this problem and to stablish prevention measures.The first objective was to study the prevalence and genotypic variability of Legionella in the water distribution systems and cooling towers from 20 hospitals in Catalonia. L. pneumophila was isolated in 73 out of 196 water samples analysed, representing 17 of the 20 hospitals included in the study. The degree of colonización ranged from 200 to 74.250 cfu/L in peripheral points and, from 200 to 55.500 cfu/L in central points. L. pneumophila sg. 1 was recovered in the 39.7 % of the positive samples. Twenty-five PFGE patterns were detected by pulsed-field gel electrophoresis (PFGE). Each hospital had its own Legionella PFGE patterns, which was not shared with any other hospitals. A single PFGE pattern was identified in 10 hospitals, 2 PFGE patterns were observed in 6 hospitals, and 1 hospital exhibited 3 different PFGE patterns. The results of this study were important in establishing the need for environmental cultures in hospitals in the legislation on the prevention of legionellosis in Spain and Catalonia post (RD 865/2003 and RD352/2004). It was highlighted the need to implement specific techniques for diagnosis of legionellosis in case of nosocomial pneumonia to determine the actual incidence of each hospital.In the second objective, we attempt to answer the question of whether the virulence of L. pneumophila isolates in the water distribution systems in hospitals influences the number of PFGE patterns coexisting in the same hospital and occurrence of clinical cases in the centre. The cytopathogenicity of 22 L. pneumophila isolates with different PFGE pattern from 17 hospitals was determined by assessing the dose of bacteria necessary to produce 50% cytopathic effect (CPED50) in U937 human-derived macrophages. All isolates were able to infect and grow in macrophage-like cells (range log10 CPED50: 2.67-6.73 cfu/ml). Five groups were established and related to the serogroup, the number of PFGE patterns coexisting in the same hospital water distribution system, and the possible reporting of hospital-acquired Legionnaires' disease cases. L. pneumophila serogroup 1 isolates had the highest cytopathogenicity (p=0.003). Moreover, a trend to more cytopathogenic groups (groups 1-3) in hospitals with more than one PFGE pattern of L. pneumophila in the water distribution system (60% vs. 17%) and in hospitals reporting cases of hospital-acquired Legionnaires' disease (36.3% vs. 16 . 6%) was observed. We conclude that the cytopathogenicty of environmental L. pneumophila should be taken into account in evaluating the risk of a contaminated water reservoir in a hospital and hospital acquisition of Legionnaires' disease.In the third objective, the molecular epidemiology of clinical and environmental Legionella species isolates was studied in seven hospitals from 1989 to 2006. The number of environmental pulsed field gel electrophoresis (PFGE) patterns ranged from one to nine according to the hospital. Genomic PFGE pattern persistence was observed in 71% of the hospitals, even after 17 years in some hospitals, and the relationship between environmental and clinical isolates was established. The isolates associated with hospital-acquired Legionnaires' disease corresponded to the persistent environmental PFGE patterns of Legionella pneumophila in potable water supplies

La malaltia del legionari i l'aigua als hospitals

La legionel·losi nosocomial, o malaltia del legionari adquirida a l'hospital, és una afecció relacionada amb la presència del bacteri Legionella als sistemes de distribució d'aigua sanitària hospitalària. Aquest treball identifica l'existència d'una elevada variabilitat i estabilitat genètica dels patrons moleculars del bacteri analitzats en el sistema d'aigua de 7 hospitals