Catalase-negative, methicillin-resistant Staphylococcus aureus as a cause of septicemia

Abstract

A catalase-negative methicillin-resistant Staphylococcus aureus (MRSA) was isolated from blood, venous catheter spike and bone marrow collected from an HIV-positive man with lobar pneumonia and sepsis after ten days of hospitalization. The isolate was resistant to oxacillin (positive for penicillin-binding protein 2'), ceftriaxone, clindamycin and clarithromycin, and susceptible to vancomycin. This is the first case of septicemia due to a catalase-negative S. aureus reported in Brazil, and, to our knowledge, it is the first case of catalase-negative MRSA reported in the literature. We believe that the patient acquired the S. aureus infection within the hospital environment since it was isolated ten days after hospitalization, it was isolated in a venous catheter spike, and the antibiotic resistance profile is similar to other S. aureus isolates recovered from infections in our hospital. Catalase-negative Methicillin-resistant Catalase-negativo Resistente a meticilina laboratories should be encouraged to include catalase testing in their S. aureus identification protocols in order to collect more information about incidence and potential virulence of these unusual isolates. Case report In February 2000, a 30-year-old HIV-positive man who was using lamivudine, zidovudine, saquinavir, and sulfatrimethoprim for Pneumocystis prophylaxis presented Recebido em 15/03/02 Aceito para publicação em 01/08/02

Comparison of Three Methods for Routine Detection of Staphylococcus aureus Isolated from Bovine Mastitis

“…The isolates showed double hemolysis, which gave us the clue and motivated us further to continue with the identification process. The review of the literature revealed reports for catalase-negative S. аureus, but they referred to isolates of human origin [7,[12][13][14] . Piau et al [8] determined a catalasenegative S. аureus strain with point mutations in the katA gene as a possible mechanism for the loss of catalase activity.…”