RESUMO
Nosocomial infections by methicillin-resistant Staphylococcus aureus (MRSA) are an increasing cause of morbidity and mortality. Recently, a worldwide increase of community-acquired MRSA infections has also been recorded. The purpose of this study was to assess the frequency of MRSA isolation from in- and outpatients admitted to an academic teaching hospital near Torino (northwest Italy) in 1 year and to characterize 90 clinical isolates of MRSA collected in the same period. Antimicrobial susceptibility and the presence in the isolates of the Panton-Valentine leukocidin (PVL) gene were assessed. Molecular epidemiology was performed by SCCmec and capsule typing, and by pulsed-field gel electrophoresis. The global proportion of MRSA isolated was 33.1%. Characterization performed on 90 MRSA revealed a high percentage of resistance to ciprofloxacin and erythromycin, and the presence of the PVL gene in one strain only. Most of the MRSA strains circulating in the Torino district belonged to SCCmec types II and I, and the 67.6% resulted positive for the cap 5 gene. The pulsotype analysis permitted to observe a clonal heterogeneity of the isolates and a higher similarity in relation to singular mec types; only few nosocomial clones could account for a local outbreak of a sporadic isolate.
Assuntos
Infecções Comunitárias Adquiridas/epidemiologia , Infecção Hospitalar/epidemiologia , Staphylococcus aureus Resistente à Meticilina/genética , Vigilância de Evento Sentinela , Infecções Estafilocócicas/epidemiologia , Antibacterianos/farmacologia , Toxinas Bacterianas/genética , Técnicas de Tipagem Bacteriana , Ciprofloxacina/farmacologia , Infecções Comunitárias Adquiridas/microbiologia , Infecção Hospitalar/microbiologia , DNA Bacteriano/genética , Farmacorresistência Bacteriana , Eritromicina/farmacologia , Exotoxinas/genética , Hospitais de Ensino , Humanos , Sequências Repetitivas Dispersas , Itália/epidemiologia , Leucocidinas/genética , Resistência a Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/classificação , Testes de Sensibilidade Microbiana , Epidemiologia Molecular , Infecções Estafilocócicas/microbiologia , Fagos de Staphylococcus/genéticaRESUMO
Achromobacter xylosoxidans is a ubiquitous Gram-negative non-fermenting rod, recently characterized as an emerging pathogen in cystic fibrosis (CF) patients. Its pathogenic potential and prevalent transmission routes are still unclear. This study investigated the PFGE genetic pattern and antimicrobial resistance profile of 42 A. xylosoxidans isolates obtained over 4 years from the respiratory tract of 22 CF patients. By genotypic analysis, 31 isolates were attributed to 8 distinct PFGE patterns (A-H), whereas 11 isolates were not typable because their DNA was not restricted by XbaI and DraI restriction enzymes. The majority of the isolates showed multidrug resistance; imipenem and piperacillin were the most active drugs. During the course of A. xylosoxidans chronic infection forced expiratory volume and body mass index values were not significantly lowered. The demonstration of widespread antibiotic resistance underscores the importance of antibiogram-directed therapy. Our data suggest that in some cases the infection may have been acquired from other patients or from a common contaminated source. Further epidemiological studies may be important for the design and implementation of prophylactic measures in CF centers.