[Multicenter study of resistance in enterococci. The role of teicoplanin. Spanish Group for Study and Surveillance of Resistance]

Enterococci are a frequent cause of nosocomial and community infections, especially the E. faecalis and E. faecium species. They often show intrinsic resistance to cephalosporins and quinolones, and acquired resistance to other antimicrobials, such as glycopeptides, has also been described. In order to test the impact of antibiotic resistance in enterococci isolated from infections, we carried out a multicenter study in 19 hospitals in Spain. We verified whether resistance to a high concentration of aminopenicillins and aminoglycosides was high (30.86% for ampicillin, 32.32% for gentamicin at a 500 micrograms dose, 55.93% for streptomycin at a 1000 micrograms dose) while the resistance to glycopeptides was low (1.8% for vancomycin and 1% for teicoplanin). It was also shown that teicoplanin had greater intrinsic activity than vancomycin, with teicoplanin 0.5 mg/l inhibiting 86.1% of the strains studied, whereas only 12.8% were inhibited with the same concentration of vancomycin.

[Phase contrast microscopy in the detection of bacteriuria]

Despite the recognized superiority of traditional culture methods to investigate bacteriuria their routine use in population studies is costly. We proposed to use Phase contrast microscopy (PCM) which allows clear visualization of bacteria with no centrifugation or staining. Urine samples from 214 patients were studied by PCM and results compared to those obtained by quantitative culture. MCF had 95% sensitivity and 96% specificity. Therefore, PCM may be used to screen urine samples for further bacteriologic study with the highest chance of obtaining positive cultures.