ABSTRACT
Cryptococcus neoformans is the major cause of fungal meningitis, a potentially lethal mycosis. Bird excreta can be considered a significant environmental reservoir of this species in urban areas, thirty-three samples of pigeon excreta were collected within the city of Vitoria, Brazil. Cryptococcus neoformans was isolated and identified using standard biochemical assays in ten samples. PCR amplification with primer M13 and orotidine monophosphate pyrophosphorylase (URA5) gene-restriction fragment length polymorphism (RFLP) analysis discerned serotypes and genotypes within this species. All isolates were serotype A (C. neoformans var. grubii) and genotype VNI. The two alternative alleles a and α at the mating type locus were determined by PCR amplification and mating assays performed on V8 medium. All isolates were MAT α mating type but only 50 percent were able to mate in vitro with the opposite mating type MAT a tester strains (JEC20, KN99a and Bt63). This study adds information on the ecology and molecular characterization of C. neoformans in the Southeast region of Brazil.
O "complexo Cryptococcus neoformans" é constituído por C. neoformans var. neoformans, C. neoformans var. grubii, e C. gattii. Trinta por cento de amostras de excrementos de pombos coletados dentro da cidade de Vitória, Brasil, foram positivas para Cryptococcus neoformans, espécie identificada por testes bioquímicos convencionais. Amplificação por PCR com primer M13 e análise por orotidine monophosphate pyrophosphorylase (URA5) gene-"restriction fragment length polymorphism" (RFLP) distinguiram sorotipos e genotipos dentro desta espécie. Todos os isolados ambientais foram sorotipo A (C. neoformans var. grubii) e genotipo VNI. Os dois alelos alternativos a e α do locus "mating type" foram determinados por PCR e por testes de "mating" em meio V8. Todos os isolados foram "mating type" tipo MAT α mas somente 50 por cento foram capazes de conjugar in vitro com cepas MAT a, de "mating type" oposto (JEC20, KN99a e Bt63). Este estudo adiciona informações sobre a ecologia e caracterização molecular de cepas ambientais de C. neoformans, isoladas na região sudeste do Brasil.
Subject(s)
Animals , Cryptococcus neoformans/genetics , Feces/microbiology , Genes, Mating Type, Fungal , Brazil , Cryptococcus neoformans/classification , Cryptococcus neoformans/isolation & purification , Genotype , Mycological Typing Techniques , Polymerase Chain Reaction , Polymorphism, Restriction Fragment Length , Reproduction , SerotypingABSTRACT
Decontamination of Mycobacterium tuberculosis (MTB) in the environment by specific methods, such as ultraviolet light and the toxic level ozone, has been effectively used. However, the efficacy of the non-toxic level ozone in the decontamination of MTB is not well documented. This study focused on the impact of non-toxic level (0.03-0.05 part per million) ozone in normal room air on MTB on a solid medium, M7H10. The non-toxic level ozone can reduce the number of MTB colonies as compared to the control. The number of MTB colonies was rapidly reduced, more than 95 percent, during the first two hours and gradually reduced during the remaining time of the experiment. The results suggest that the non-toxic level ozone, produced by specific devices, is promising for the decontamination of solid surfaces from MTB.