Comparison of Real-Time Quantitative PCR with Northern Hybridization for Quantification of CgCDR1 and CgCDR2 Gene Expression in Candida glabrata / 대한의진균학회지

BACKGROUND: One of main mechanisms responsible for acquired azole resistance of Candida glabrata is the increased drug efflux mediated ABS transporters, which are encoded by CgCDR1 and CgCDR2 genes. OBJECTIVES: We compared real-time reverse transcriptase PCR (RT-PCR) with northern hybridization for quantitative analysis of CgCDR1 and CgCDR2 expression in bloodstream isolates of C. glabrata. METHODS: Nineteen blood isolates of C. glabrata were selected, including nine fluconazole susceptible (MIC < or =8 microgram/ml), nine susceptible dose-dependent (S-DD, MIC 16~32 microgram/ml), and one resistant (MIC 128 microgram/ml), isolates. The expression of CgCDR1 and CgCDR2 was quantified using real-time RT-PCR with ROTOR Gene 3000 (Corbettet research, Austria). The results were compared with northern hybridization with sequence-specific probes. RESULTS: Correlation of quantification results between real-time RT-PCR and northern hybridization yielded correlation coefficients of 0.92 for CgCDR1 and 0.82 for CgCDR2 gene. By both methods, no significant differences were observed in the levels of expression of CgCDR1 and CgCDR2 between fluconazole-susceptible isolates and S-DD isolates. In contrast, a strain with high fluconazole resistance (MIC 128 microgram/ml) revealed a greater abundance of CgCDR1 by both methods, compared to the other isolates. Conclusion: This study show that real-time PCR method for C. glabrata RNA quantification correlates well with traditional northern hybridization and can be a valuable alternative to northern hybridization for rapid quantification of CgCDR1 and CgCDR2 genes in clinical isolates of C. glabrata.

In-Vitro Susceptibilities of Voriconazole Against Korean Clinical Aspergillus Isolates / 대한의진균학회지

BACKGROUND: Voriconazole is a potent new triazole antifungal agent expected to be particularly useful for the treatment of invasive aspergillosis. However, in vitro susceptibility of voriconazole for clinical strains of Aspergillus species isolated in Korea has not been fully surveyed. OBJECTIVE: We determined minimum inhibitory concentrations (MICs) of voriconazole for clinical Aspergillus isolates. METHODS: A total of 100 clinical isolates of Aspergillus species (40 A. fumigatus, 24 A. flavus, 17 A. niger, 17 A. terreus and 2 A. nidulans) was tested. In vitro voriconazole susceptibility testing was accomplished utilizing the National Committee for Clinical Laboratory Standards (NCCLS) broth microdilution method M38-A. MIC of voriconazole was determined using RPMI medium at 48 h of incubation. RESULTS: Among the 100 isolates of Aspergillus species tested, 98% were inhibited by or =2 microgram/mL were 0/40 (0%) in A. fumigatus, 1/24 (4%) in A. flavus, 1/17 (6%) in A. niger, 0/17 (0%) in A. terreus, and 0/2 (0%) in A. nidulans. CONCLUSION: These data demonstrate promising in-vitro activity of voriconazole against clinical strains of Aspergillus species isolated from Korean patients.

Evaluation of Genedia HCV Rapid for Rapid Detection of Antibody to Hepatitis C Virus / 대한임상병리학회지

BACKGROUND: Hepatitis C virus (HCV) is a major agent of transfusion-associated non-A, non-B hepatitis. The best method for prevention of HCV infection through transfusion is blood donor screening using reliable diagnostic tools. Enzyme immunoassays (EIA) for detection of HCV antibody were developed, but it required equipment and time consuming. In emergency situation such as massive bleeding, HCV screening of blood donor needs more simple, rapid and reliable method. Recently, for rapid detection of HCV antibody, Genedia HCV Rapid assay was developed. To evaluate the usefulness of this assay, comparative studies with third generation anti- HCV EIA and two HCV confirmatory tests (Genedia HCV Confirm 4.0 and Chiron RIBA HCV 3.0 SIA) were performed. METHODS: A total of 156 sera (106 positive and 50 negative), screened by second generation IMx anti-HCV assay (Abbott 2.0; Abbott Laboratories, U.S.A.), were examined with Genedia HCV Rapid (Green Cross, Korea) and Genedia HCV ELISA 3.0 (Green Cross, Korea). The discrepant sera between Genedia HCV Rapid and Genedia HCV ELISA 3.0 were confirmed by both Genedia HCV Confirm 4.0 and Chiron RIBA HCV 3.0 SIA. RESULTS: The concordance rates of Abbott 2.0 vs Genedia HCV Rapid, Abbott 2.0 vs Genedia HCV ELISA 3.0, and Genedia HCV Rapid vs Genedia HCV ELISA 3.0 were 88.4%, 89.7%, and 96.1%, respectively. The sensitivity, specificity, positive predictive value and negative predictive value of Genedia HCV Rapid for Genedia HCV Confirm 4.0 were 97.7%, 100%, 98.9%, and 97.0%, respectively, and for Chiron RIBA HCV 3.0 SIA 97.8%, 98.5%, 98.9%, and 97.0%, respectively. Of discrepant 6 sera between Genedia HCV Rapid and Genedia HCV ELISA 3.0, 2 were positive by Genedia HCV Confirm 4.0, and 3 positive by Chiron RIBA HCV 3.0 SIA. However, 14 negative sera by both Genedia HCV rapid and Genedia HCV ELISA 3.0, which were all positive by Abbott 2.0, were all negative by two confirmatory tests. CONCLUSIONS: These data show that Genedia HCV Rapid could be used in emergency blood donor screening for HCV antibody detection.