An outbreak of catalase-negative methicillin-resistant Staphylococcus aureus.

The wide dissemination of a major epidemic methicillin-resistant Staphylococcus aureus (MRSA) clone in Brazilian hospitals (Brazilian clone) limits the value of molecular typing techniques such as pulsed-field gel electrophoresis (PFGE) for outbreak investigation. We report the first outbreak of a catalase-negative strain of MRSA, which was initially detected by the unusual result of this phenotypical test. The outbreak occurred in the Hospital Sanatorinhos de Carapicuíba, a 237-bed secondary hospital located in São Paulo, Brazil.

Comparative In Vitro Activities of Moxifloxacin (Bay 12-8039) and Other Antimicrobial Agents Against Respiratory Tract Pathogens in Brazil.

Clinical isolates of respiratory tract pathogens were susceptibility tested against six different antimicrobial agents. The in vitro activity of moxifloxacin was compared with that of levofloxacin, cefaclor, amoxicillin-clavulanate acid, azithromycin and trimethoprim-sulfamethoxazole against 111 isolates, including Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis and other species isolated from respiratory tract infections. All isolates were susceptible to moxifloxacin, except for two isolates of Pseudomonas aeruginosa which showed intermediate-resistance (MIC=6µg/mL), and one isolate of Escherichia coli which showed resistance (MIC>32µg/mL).

Antimicrobial susceptibility of coagulase-negative staphylococci and characterization of isolates with reduced susceptibility to glycopeptides.

The antimicrobial susceptibility of 239 coagulase-negative staphylococci (CNS) isolates consecutively collected from blood culture in patients admitted in a 600-bed teaching hospital was evaluated. The isolates were identified to the species level by conventional methods and the MicroScan Positive Combo Panel type 6 system, and their susceptibility to vancomycin, teicoplanin, and oxacillin were tested by agar dilution, disk diffusion, and MicroScan-WalkAway system. The species distribution was as follows: Staphylococcus epidermidis 120 (50.