Molecular typing and antifungal susceptibility of clinical sequential isolates of Cryptococcus neoformans from Sao Paulo State, Brazil.

Autor: Almeida, Ana Marisa Fusco, Matsumoto, Marcelo Teruyuki, Baeza, Lilian Cristiane, De Oliveira e Silva, Rosana Bellan, Kleiner, ALine Aparecida Pizzirani, Melhem, Márcia De Souza Carvalho, Giannini, Maria José Soares Mendes
Předmět:
Zdroj: FEMS Yeast Research; Jan2007, Vol. 7 Issue 1, p152-164, 13p, 4 Diagrams, 2 Charts, 1 Map
Abstrakt: The antifungal susceptibility profiles and the genetic variability of 83 sequential clinical isolates of Cryptococcus neoformans, including four Cryptococcus gattii isolates, obtained from 38 Sao Paulo AIDS patients with cryptococcal meningitis were assessed by electrophoretic karyotyping and random amplified polymorphic DNA (RAPD) analysis. The majority of the Cryptococcus neoformans isolates were highly susceptible to amphotericin B and fluconazole. Twenty percent of the minimum inhibitory concentration values for amphotericin B varied from 0.5 to 1 μg mL−1. For fluconazole, 22% occurred in the range 8–16 μg mL−1. Sequential isolates from nine patients showed a trend towards lower susceptibility to fluconazole, flucytosine, itraconazole and amphotericin B. The results of molecular typing by electrophoretic karyotyping and RAPD analysis showed the presence of 22 electrophoretic karyotypes (EK) and 15 RAPD profiles that were highly correlated. Our results provided evidence for the occurrence of genetic changes in some strains associated with microevolution during the course of infection. We also observed both microevolution and simultaneous coinfection with two distinct Cryptococcus neoformans strains in one patient. In some patients, we found changed EK- and RAPD patterns in association with increased MIC values. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index