Moxifloxacin and biofilm production by coagulase-negative staphylococci.

The in vitro activity of moxifloxacin against 41 strains of coagulase-negative staphylococci was determined. A relationship between the activity of moxifloxacin and biofilm formation was detected. Biofilm-producing strains were more resistant to moxifloxacin than biofilm-negative strains. Our global results obtained with six strains of Staphylococcus epidermidis showed that subinhibitory concentrations of moxifloxacin did not significantly modify biofilm formation. On the other hand, moxifloxacin concentrations of 2, 10, 50 and 100 x MIC produced a log decrease in viable count (included in a biofilm) of 0.20, 0.37, 1.10 and 1.69, respectively.

Resistance to vancomycin, LY333328, ciprofloxacin and trovafloxacin of community-acquired and nosocomial strains of Enterococcus faecalis isolated in Badajoz (Spain) with and without high-level resistance to streptomycin and gentamicin.

In vitro resistance of community-acquired and nosocomial strains of Enterococcus faecalis isolated in Badajoz (Spain) were determined by a microdilution method. The isolates were identified with conventional MicroScan Pos Combo 4 I dehydrated panels. No resistance to glycopeptides was found, but LY333328 was 2-4 times more active than vancomycin. In the nosocomial strains, high-level resistance to streptomycin (HLRS) was 54.7%, and high-level resistance to gentamicin (HLRG) was 38.1%. Resistance to ciprofloxacin and trovafloxacin was 45.3 and 38.9%, respectively. In the community-acquired isolates, HLRS, HLRG, resistance to ciprofloxacin and resistance to trovafloxacin were 44.2, 17.3, 15.4 and 13.5%, respectively. Trovafloxacin was 2-4 times more active than ciprofloxacin against both groups of strains. An association between high-level resistance to aminoglycosides and resistance to fluoroquinolones was noted. The resistance to aminoglycosides did not influence the activity of vancomycin and LY333328.

[Pathogenicity of Enterococcus spp. Characteristics of 169 hospital isolates]. / Patogenicidad de Enterococcus spp. Características de 169 aislamientos hospitalarios.

BACKGROUND: To know the characteristics of Enterococcus spp. strains isolated in the hospital; to analyse the importance of this microorganism and its resistance to antimicrobial agents. PATIENTS AND METHODS: Retrospective analysis of the case histories of 169 patients with Enterococcus spp. isolates, selected at random at the Infanta Cristina Hospital in Badajoz. Investigation was carried out on: age, date of admission and discharge, clinical symptoms, risk factors, previous antibiotic treatment, clinical and microbiological evolution, recommended treatment and prescribed treatment. Identification of microorganisms and antibiogram with Pos Combo 41 microScam panels, read on Baxter WalkAway-40 equipment. RESULTS: The most frequently found species was Enterococcus faecalis. In 75 cases the isolations were polymicrobial. The enterococci were isolated mainly from urinary infections (27%), skin infections (20%), intrabdominal infections (14%) and infections from surgical wounds (14%). The existence of peripheral catheter was the main risk factor. All the strains of E. faecalis were susceptible to the glycopeptides. Two strains of Enterococcus faecium were not susceptible to vancomycin and one of these was not susceptible to teicoplanin. Mortality was from 21-27.5%. CONCLUSIONS: Enterococcus spp. is frequently isolated in nosocomial infections, although in approximately half the cases it is associated with other bacteria. For this reason, it is not always possible to determine its pathogenic contribution. The isolated strains, except two strains of E. faecium, are susceptible to vancomycin. A relation exists between high resistance to aminoglucosides and resistance to fluoroquinolones.