RESUMO
Daptomycin is one of the last therapeutic resources for multidrug-resistant gram-positive bacteria. Despite its structural similarities with glycopeptides, its mechanisms of action and resistance are different and in some respects are not completely understood. Mutations in several genes have been associated with daptomycin resistance, especially in mprF, walkR, rpoB and rpoC, but their role and importance remain to be elucidated. We have studied mutations in 11 genes, which have been previously associated with daptomycin non-susceptibility, in nine daptomycin-non-susceptible Staphylococcus aureus clinical isolates (daptomycin MIC: >1 mg/L). Susceptibility to daptomycin, vancomycin, linezolid, oxacillin, telavancin and dalbavancin was studied. walkR, agrA, cls1, cls2, fakA, pnpA, clpP, prs, rpoB, rpoC and mprF were amplified by PCR and sequenced. The sequences were compared with the S. aureus ATCC 25923 complete genome (GenBank gi: 685631213) by using BLAST® software. We did not find any changes in walkR, pnpA, prs and clpP. All isolates excepting isolate MSa5 showed a high number of significant mutations (between 13 and 25 amino acid changes) in mprF. Most isolates also showed mutations in the rpo genes, the cls genes and fakA. Daptomycin non-susceptibility in S. aureus clinical isolates seems to be reached through different mutation combinations when compared to S. aureus ATCC 25293. Especially mprF and cls1 showed very high polymorphism in most isolates. Meanwhile, one isolate, MSa5, showed only single mutation in mprF (P314T).
RESUMO
OBJECTIVE: The increase in morbidity and mortality associated the influenza virus infections represents an important global challenge, with particular relevance within health institutions.The aim of the study was to highlight the impact, repercussions and characteristics of the nosocomial transmission of influenza virus. METHODS: A sample of 286 hospitalized patients in a third-level hospital with confirmed influenza (virus RNA in respiratory specimens) is included. The study design was observational, through the collection of positive microbiological results from the 2016-2017 season. A comparative statistical analysis was carried out between cases of community-acquired influenza and hospital-acquired cases. RESULTS: 14.3% of the total sample (41 cases) was considered of nosocomial origin. Significant differences were observed in the percentage of vaccinated between hospital-acquired (34.1%) and community-acquired (50.2%); and in the number of days of hospitalization after diagnosis between both groups. The attack rate was 0.66%. CONCLUSIONS: The nosocomial acquisition of the influenza virus resulted in a greater severity of the process and in the increase of days of hospital stay. Strict adherence to control measures and epidemiological surveillance of influenza cases has allowed to reduce the attack rate.
OBJETIVO: El incremento de la morbimortalidad asociado a la infección por el virus de la gripe supone un importante reto a nivel mundial, con especial relevancia dentro de las instituciones sanitarias. El objetivo del estudio fue analizar el impacto, repercusiones y características de la transmisión nosocomial del virus de la gripe. METODOS: Se incluyó una muestra de 286 pacientes hospitalizados en un centro de tercer nivel con gripe confirmada (ARN del virus en muestras respiratorias). El diseño del estudio fue observacional, mediante recogida de los resultados microbiológicos positivos de la temporada de gripe 2016-2017. Se realizó un análisis estadístico comparativo entre los casos de gripe comunitaria y los casos nosocomiales. RESULTADOS: El 14.3% del total de la muestra (41 casos) se consideró de origen nosocomial. Se observaron diferencias significativas en el porcentaje de vacunados entre los casos de infección nosocomial (34,1%) y comunitaria (50,2%), y en el número de días de ingreso tras diagnóstico (12 ±22 días para los casos nosocomiales y 6 ±8 días para los comunitarios). La tasa de ataque fue del 0,66%. CONCLUSIONES: La adquisición nosocomial del virus de la gripe se tradujo en una mayor gravedad del cuadro y en el incremento de los días de estancia hospitalaria. El estricto cumplimiento de las medidas de control y vigilancia epidemiológica de los casos de gripe ha permitido lograr una tasa de ataque reducida.
