Genotyping, serotyping and determination of mating-type of Cryptococcus neoformans clinical isolates from São Paulo State, Brazil

Abstract

SUMMARYThe basidiomycetous yeast Cryptococcus neoformans is an important fungal pathogen mainly in immunocompromised patients. In this study, 47 clinical isolates of C. neoformans from regions of São Paulo State were studied serologically by using the Crypto Check Iatron RM 304-K kit, their genetic diversity was estimated by PCR-fingerprinting with a microsatellite-specific sequence (GACA) 4 , RAPD with primer 6 (Amersham Pharmacia Biotech), PCR-restriction fragment length polymorphism (RFLP) analysis of the phospholipase B gene (PLB1) digested with AvaI and mating type analysis by PCR. All 47 strains isolated from HIV positive patients included in this study were serotype A and MATα. The majority of the isolates (45/47) were VNI and only two were VNII by PCR-fingerprinting and PCR-RFLP analysis. High degree of homogeneity was observed when (GACA) 4 was used, being highly correlated (> 0.9). In contrast, the RAPD analysis was more heterogeneous with higher number of molecular profiles. By PCR-RFLP, no new molecular type was found, enhancing the suggestion that the differences based on conserved gene as PLB1, can be resultant of ongoing divergent evolution within the C. neoformans complex, into the current eight subtypes. Our results furnish new information on the molecular epidemiology of C. neoformans in the southeast region of Brazil.

Molecular typing and in vitro antifungal susceptibility of Cryptococcus spp from patients in Midwest Brazil

“…However, in Brazil, molecular epidemiology studies are still required to elucidate the distribution of molecular types in all five Brazilian regions. Despite this, the few epidemiological studies conducted in Brazil have demonstrated differences in the distribution of the genotypes of these species in these regions [17][18][19][20][21]36]. In Mato Grosso, this is the first report describing the molecular types circulating in the state capital of Cuiabá.…”

“…C. neoformans is the species with the largest number of isolates among species belonging to the Cryptococcus complex [5,[16][17][18]37]. Currently, an increasing number of cases of cryptococcosis have been reported in patients without HIV.…”

“…In Brazil, cryptococcosis caused by C. neoformans occurs in all regions of the country [5,[16][17][18][19][20]. However, C. gattii has emerged as a primary pathogen infecting immunocompetent individuals, particularly children, adolescents and young adults in northeastern Brazil, where cryptococcosis is characterized by high mortality rates [18,[20][21][22].…”

Molecular characterization of environmental Cryptococcus neoformans isolated in Vitoria, ES, Brazil

“…Only a few Brazilian studies have investigated the molecular types of environmental Cryptococcus 1,2,3,22,24,28,35 . The distribution of molecular types using the specific primer M13 shows the predominance of VNI (serotype A) in surveyed regions.…”

“…It is worthwhile to note the presence of VNIV (serotype D) in eucalypt trees in the deep south of Brazil, a subtropical region 2,28 , and of VGI (C. gattii serotype B) in excreta of psittaciformes in the same region 1 . Study of clinical isolates in São Paulo showed that all of them were serotype A and the majority belonged to the molecular type VNI 22 .…”