RESUMO
BACKGROUND: Currently fungal infections have been increasing in clinical aspect. Among them Candida albicans is considered as the most pathogenic. National Committee for Clinical Laboratory Standards(NCCLS) recommends broth macrodilution method for antifungal susceptibility test, but it is difficult to perform. E test is a relatively easy method to perform for the susceptibility testing. So in this study, antifungal susceptibility procedures were compared to determine MIC for fluconazole against 130 Candida strains isolated from clinical specimens. METHOD: The tests including were microdilution method, E test and disk diffusion method. The latter two tests were performed in casitone agar and the former test performed in RPMI 1640 media(Sigma Chemical co. St. Louis, USA). MIC was determined after 24 hrs of incubation. We used Candida albicans ATCC 90018 and Candida parapsilosis ATCC 90028 as controls. A total of 130 strains(93 C. albicans, 29 C. tropicalis, 5 C. parapsilosis and 3 C. glabrata) were tested. RESULTS: The MIC50 and MIC90 of broth microdilution test for C. albicans was > OR =64 microgram/mL equivalently. Agreement of > OR = +/-2 dilution between broth microdilution test and E test was 54 %, and the concordance rate was 55%. The concordance rate between E test and disk diffusion was 90%. CONCLUSIONS: From this study, we conclude that E test can be used as a alternative and convenient method to macrodilution method to determine MIC of fluconazole. But it is necessary for attention to microcolonies surrounding the E test strip. Disk diffusion method is rapid and also can be used as an alternative and convenient method.
Assuntos
Ágar , Candida albicans , Candida , Difusão , FluconazolRESUMO
BACKGROUND: Methicillin-resistant Staphylococcus aureus is a major etiologic agent of hospital acquired infection. Coagulase negative staphylococci (CNS) species are previously regarded as contaminants. However nowadays CNS were regarded as an important cause of bacteremia. So in this study we wanted to analyze the patterns of plasmids and antimicrobial susceptibility test of Staphylococcus species isolated from clinical specimens. METHOD: Plasmid DNA was extracted and then processed through restriction enzyme digestion for plasmid analysis of S. aureus and antimicrobial susceptibility, which was done by agar dilution method. For S. epidermidis plasmid analysis was done without enzyme digestion. RESULTS: All of MRSA have 1 to 5 plasmids. There exists 6 patterns of S. aureus plasmid without enzyme digestion. With EcoRI and HindIII digestion pattern were more distinct and clear. For S. epidermidis enzyme digestion is not needed. Antimicrobial susceptibility patterns of S. aureus are simple whereas S. epidermidis showed variable patterns. CONCLUSIONS: For the plasmid analysis of S. aureus restriction enzyme digestion is required and for the S. epidermidis, the pattern of plasmids are variable so without restriction enzyme analysis we can obtain several patterns. Plasmid analysis will be used as a good epidemilogical tool for Staphylococcus.