RESUMEN
La resistencia a carbapenemes en enterobacterias representa una situación de alto impacto clínico debido a las limitadas opciones terapéuticas disponibles para el tratamiento de las infecciones causadas por estos microorganismos multirresistentes que cursan con altas tasas de morbilidad y mortalidad. En nuestro país, en los últimos 5 años, se observó la diseminación de aislamientos de Klebsiella pneumoniae portadores de carbapenemasa de tipo KPC pertenecientes al ST258, clon diseminado mundialmente. En nuestro hospital la incidencia de episodios fue aumentando, especialmente la infección del sitio quirúrgico y las bacteriemias. En el último bienio se observó la diseminación del mecanismo de resistencia a otras enterobacterias y probablemente a otros secuenciotipos de K pneumoniae con mayor sensibilidad a antibióticos no ß-lactámicos. Se hace necesario instaurar las correctas medidas de prevención y control para evitar la diseminación de estos patógenos.
The presence of carbapenem -resistant Enterobacteriaceae in clinical settings represents a concerning issue due to the limited therapeutic options available for the treatment of the infections caused by these multi-drug resistant bacteria which usually have high mortality rates. The spread of Klebsiella pneumoniae isolates belonging to ST258 was observed in the last 5 years in our country. In our hospital the number of episodes has grown with the years and the most prevalent infections were the surgical site and bacteremia. In the last 2 years KPC spread to other Enterobacteriaceae and probably to other STs in K pneumoniae which showed different susceptibility patterns to non ß-lactamic antimicrobials. We believe that it is vital to install the appropriate measures to prevent and control the dissemination of these microorganisms.
Asunto(s)
Humanos , Masculino , Femenino , Adolescente , Adulto , Persona de Mediana Edad , Anciano , Anciano de 80 o más Años , Adulto Joven , Carbapenémicos/administración & dosificación , Enterobacteriaceae/patogenicidad , Klebsiella pneumoniae/patogenicidad , Infección Hospitalaria , Farmacorresistencia Microbiana , Hospitales Universitarios , Control de InfeccionesRESUMEN
The emergence of vancomycin intermediate Staphylococcus aureus (VISA) and heterogeneous VISA (hVISA) is of major concern worldwide. Our objective was to investigate the prevalence, phenotypic and molecular features of hVISA strains isolated from bacteremic patients and to determine the clinical significance of the hVISA phenotype in patients with bacteremia. A total of 104 S. aureus blood isolates were collected from a teaching hospital of Argentina between August 2009 and November 2010. No VISA isolate was recovered, and 3 out of 92 patients (3.3%) were infected with hVISA, 2 of them methicillin-resistant S. aureus (MRSA) (4.5% of MRSA). Macro Etest and prediffusion method detected 3/3 and 2/3 hVISA respectively. Considering the type of bacteremia, the three cases were distributed as follows: two patients had suffered multiple episodes of bacteremia (both hVISA strains recovered in the second episode), while only one patient had suffered a single episode of bacteremia with hVISA infection. MRSA bloodstream isolates exhibiting the hVISA phenotype were related to HA-MRSA Cordobes clone (ST5-SCCmec I-spa t149) and MRSA Argentinean pediatric clone (ST100-SCCmec IVNV-spa t002), but not to CA-MRSA-ST30-SCCmec IV-spa t019 clone that was one of the most frequent in our country. Although still relatively infrequent in our hospital, hVISA strains were significantly associated with multiple episodes of bacteremia (p=0.037) and genetically unrelated.
