Two new colorimetric methods for early detection of vancomycin and oxacillin resistance in Staphylococcus aureus.

We developed two colorimetric methods for the detection of vancomycin- and oxacillin-resistant Staphylococcus aureus in

[Phospholipase activity of Candida species isolated from different clinical samples]. / Degisik klinik orneklerden izole edilen Candida türlerinde fosfolipaz aktivitesinin arastirilmasi.

In this study, the phospholipase activity that was suggested to be important in the pathogenesis of Candida infections, has been investigated. A total of 109 Candida strains (80 Candida albicans, 10 C. tropicalis, 6 C. glabrata, 6 C. guilliermondii, 4 C. parapsilosis, 2 C. krusei, 1 C. kefyr) which were isolated from various clinical specimens (blood, cerebrospinal fluid, parasynthesis specimens, catheter samples, bronchoalveolar lavage fluid, tracheal aspirate, liver abscess) have been included in the study. Phospholipase activities were evaluated by modified plate method. Phospholipase activity (Pz) was determined as the ratio of colony diameter to the diameter of precipitation zone with the colony. While 61.3% (49/80) of C. albicans strains were found to be positive for phospholipase activity, none of the non-albicans Candida isolates exhibited phospholipase activity. The mean Pz coefficient value of phospholipase secreting isolates was calculated as 0.805 +/- 0.08. There was no statistically significant difference between the phospholipase activity of the isolates according to their isolation sites (chi2 = 5.5; p = 0.137).

Susceptibilities of Mycobacterium tuberculosis to isoniazid and rifampin on blood agar.

In this study, blood agar was used instead of 7H10 agar for the susceptibility testing of 34 clinical isolates of Mycobacterium tuberculosis to isoniazid (INH) and rifampin (RIF) in accordance with the NCCLS. The BACTEC 460 TB system (Becton Dickinson, Sparks, Md.) was used as a "gold standard." Results for both media were in agreement for RIF and INH at 100 and 94.1%, respectively. For INH, the specificity, sensitivity, positive predictive value, and negative predictive value were found to be 71.4, 100, 93.1, and 100%, respectively, while these values were 100% for RIF. In addition, the results of the susceptibility test performed with blood agar were obtained on day 14 of incubation. In conclusion, results were obtained much earlier with blood agar (2 weeks) than with 7H10 agar (3 weeks), and the results of this study suggest that blood agar may be used as an alternative medium for the susceptibility testing of M. tuberculosis to INH and RIF.