Molecular typing and antifungal susceptibility of clinical sequential isolates of Cryptococcus neoformans from Sao Paulo State, Brazil.
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 micro g mL(-1). For fluconazole, 22% occurred in the range 8-16 mug 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.
Almeida
Ana Marisa Fusco
AM
Programa de Pós Graduação em Biotecnologia, Instituto de Química, UNESP, Araraquara, SP, Brasil.
Matsumoto
Marcelo Teruyuki
MT
Baeza
Lilian Cristiane
LC
de Oliveira E Silva
Rosana Bellan
RB
Kleiner
Aline Aparecida Pizzirani
AA
Melhem
Márcia de Souza Carvalho
Mde S
Mendes Giannini
Maria José Soares
MJ
D017088:AIDS-Related Opportunistic Infections / Q000453:epidemiology* / Q000382:microbiology; D000935:Antifungal Agents / Q000494:pharmacology*; D001938:Brazil / Q000453:epidemiology; D003455:Cryptococcus neoformans / Q000145:classification* / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D005838:Genotype; D006801:Humans; D007621:Karyotyping; D016919:Meningitis, Cryptococcal / Q000453:epidemiology* / Q000382:microbiology; D008826:Microbial Sensitivity Tests; D019105:Random Amplified Polymorphic DNA Technique
D000935:Antifungal Agents