Resumen

Background: The aim of this study was to investigate the changes with respect to antibacterial resistance and genotype of Enterococcus species isolated in a university hospital during two periods five years apart. Methodology: 321 strains of Enterococcus were isolated from clinical samples, or faecal screening, during January 1998 to September 1999 (168 isolates) and from May 2003 to April 2004 (153 isolates). Phenotypic resistance to clinically relevant drugs was determined by agar dilution, E-test or by disc diffusion, and genotypic resistance by PCR for specific resistance genes. Genotyping of resistant strains was by arbitrarily primed PCR (AP-PCR) and pulsed-field gel electrophoresis (PFGE). Results: All 321 isolates were susceptible to teicoplanin. Six Enterococcus gallinarum isolates (4 from the first period) and two Enterococcus faecalis isolates (1 from the first period) showed intermediate resistance to vancomycin. The vanC1 gene was amplified in 6/8 vancomycin intermediate isolates and the remaining two isolates, both Enterococcus faecalis, gave no product after PCR for vanA, B, C1 or C2/C3). Four isolates of E. casseliflavus and three E. gallinarum harboured vanC1 and vanC2/C3 and gave MICs to vancomycin of 4mg/mL. High level gentamicin resistance was detected in 37.5% of isolates in the first period and 30.0% in the second period. Ampicillin resistance was also found in 41.1% of the isolates in the first period and 20.9% in the second period. Molecular typing showing epidemiologic relatedness were detected in two E. gallinarum in the first period as well as in two E. gallinarum and two E. casseliflavus in the second period. Conclusions: The incidence of vancomycin resistance is not high in Malatya; however, high level gentamicin resistance is common. Closely related vanC positive VRE strains suggest that infection control procedures should be improved.

Palabras clave: Enterococci glycopeptide resistance VanC VRE high level gentamicin resistance genotypic analysis.

2007-11-06   |   963 visitas   |   Evalua este artículo 0 valoraciones

Vol. 1 Núm.2. Octubre 2007 Pags. 151-157 J Infect Developing Countries 2007; 1(2)