ABSTRACT
BACKGROUND: Penicillium marneffei (P. marneffei) is an emerging pathogenic fungus that can cause invasive mycosis in patients with AIDS. The epidemiological features of P. marneffei infection in AIDS patients in Guangdong province remain unclear so far. This study aimed to investigate the genetic diversity within a population of 163 P. marneffei isolates obtained from AIDS patients and search for the dominant clinical strains in Guangdong province. METHODS: One hundred and sixty-three P. marneffei isolates obtained from AIDS patients in Guangdong province during January 2004 and December 2009 were studied by randomly amplified polymorphic DNA (RAPD) using two random primers (H2 and H22). The degree of similarity between samples was calculated through similarity coefficients from RAPD fragment data and the dendrogram was assessed using the unweighted pair group method with arithmetic mean (UPGMA). RESULTS: Two primers showed a high degree of discrimination and good stability. Primer H2 yielded eight different patterns (H2-1 to H2-8) among 163 isolates with the discriminatory power being 0.413. Primer H22 identified seven types (H22-1 to H22-7) among 163 isolates with the discriminatory power being 0.467. Genetic similarity coefficients based on RAPD data among 163 P. marneffei isolates ranged from 0.681 to 0.957, 61.96% of which were no less than 0.83. The discriminatory power of the two primers was 0.524. One hundred and sixty-three P. marneffei isolates were clustered into nine distinct groups (groups I to IX) at the similarity coefficient value of 0.83 and group I was the most common, including 101 strains (61.96%). CONCLUSION: The RAPD analyses could provide important information as to the degree of genetic diversity and the relationship among clinical P. marneffei isolates, revealing genetic polymorphism and dominant strains.
Subject(s)
Acquired Immunodeficiency Syndrome/microbiology , Genetic Variation/genetics , Penicillium/genetics , Random Amplified Polymorphic DNA Technique/methods , Humans , Penicillium/classificationABSTRACT
AIM: To explore the value of detecting hepatitis C virus core antigen in HCV infected diseases. METHODS: The HCV-RNA was tested by fluorescent quantitative polymerase chain reaction (FQ-PCR). The core antigens of HCV and anti-HCV were tested by enzyme-linked immunosorbent assay (ELISA). RESULTS: The positive rate of HCV-RNA in 191 patients was 71.2%, about 136 in 191. The positive rate of anti-HCV was 97.4%, about 186 in 191. The positive rate of HCV core antigen was 33.0%, about 63 in 191. After antiviral therapy for 2 patients,their HCV-RNA and anti-HCV were detected negative but their HCV core antigen was detected positive. In another patient, his anti-HCV was negative but his HCV core antigen was positive. CONCLUSION: As a supplemental test for anti-HCV examination the detection of HCV core antigen is of important clinical value in HCV infection diagnosis.
