Heterogeneous resistance to vancomycin and teicoplanin among Staphylococcus spp. isolated from bacteremia.

This study evaluated the BHIA screening method with 4 or 6 mug/mL of vancomycin to detect glycopeptides heteroresistant staphylococci strains isolated from bacteremia. A total of 213 staphylococci strains were isolated from 106 patients between October/2001 and November/2002 in a tertiary hospital in Rio de Janeiro city. Fifty-seven (53.

Simplified and reliable scheme for species-level identification of Staphylococcus clinical isolates.

Reliable and rapid identification of staphylococcal strains continues to be a problem faced by many microbiology laboratories. This study evaluates a simplified method that uses a flowchart to assist in the identification of 12 clinical species of Staphylococcus, including eight subspecies. A total of 198 isolates and 11 control strains were identified by the reference method, which employed 22 tests.

Heterogeneous resistance to vancomycin in Staphylococcus epidermidis, Staphylococcus haemolyticus and Staphylococcus warneri clinical strains: characterisation of glycopeptide susceptibility profiles and cell wall thickening.

The population analysis profile (PAP) method as well as analysis of autolytic activity and cellular ultrastructure by transmission electron microscopy (TEM) were used to characterise Staphylococcus epidermidis, Staphylococcus haemolyticus and Staphylococcus warneri clinical strains with reduced susceptibility to glycopeptides. All strains showed heterogeneous profiles to vancomycin and teicoplanin by the PAP method. Subpopulations that grew in the presence of high concentrations of each drug were selected from the PAP as derivative strains.

Coagulase-negative staphylococci: comparison of phenotypic and genotypic oxacillin susceptibility tests and evaluation of the agar screening test by using different concentrations of oxacillin.

This study evaluated the oxacillin susceptibilities of 152 coagulase-negative staphylococcal (CoNS) strains of 12 species by disk diffusion; agar dilution; E-test; the slide latex agglutination test (Slidex MRSA Detection test; bioMérieux S/A, Paris, France); the agar screening test with 1, 2, 4, or 6 microg of oxacillin per ml and incubation for 24 or 48 h; and detection of the mecA gene by PCR. The results revealed that the agar screening test with 4 micro g of oxacillin per ml and incubation for 48 h was superior to any single phenotype-based susceptibility assay, presenting a sensitivity and a specificity of 100% each. For the different methods evaluated, the sensitivities and specificities were as follows: for disk diffusion, 94.