Genotype and mating type distribution within clinical Cryptococcus neoformans and Cryptococcus gattii isolates from patients with cryptococcal meningitis in Uberaba, Minas Gerais, Brazil

Abstract

We molecularly characterized 81 cryptococcal isolates recovered from cerebrospinal fluid samples of 77 patients diagnosed between 1998 and 2007 as having cryptococcal meningitis in Uberaba Minas Gerais, Brazil. Fifty-seven (74%) were male with a mean age 35.6 years. Seventy-two (88.9%) of the isolates were from 68 AIDS patients and cryp-tococcosis was the first AIDS-defining condition in 38 (55.9%) patients. Cryptococcosis and AIDS were simultaneously diagnosed in 25 (65.8%) of these 38 patients. Genotypes were characterized through the use of URA5 restriction fragment length polymorphisms analysis, the genetic variability was determined using PCR-fingerprinting with the minisatellite-specific primer M13, and the mating type and serotypes were established by PCR. Seventy-six of the 81 isolates were Cryptococcus neoformans (93.8%), while the remaining five were C. gattii (6.1%), but all were mating type α. C. neoformans isolates were genotype VNI (serotype A), while C. gattii isolates were VGII. Four of the latter isolates were identical, but only two were from AIDS patients. Six of the nine isolates from non-AIDS patients were VNI. PCR fingerprints of the isolates from two of the three AIDS patients with clinical relapse were 100% identical. The predominance of VNI and mating type α is in accordance with data from other parts of the world. The occurrence of VGII in Minas Gerais indicates a geographical expansion within Brazil.

Keywords:

• Cryptococcus neoformans
• Cryptococcus gattii
• mating type
• URA5-RFLP
• PCR-fingerprinting

Acknowledgments

This research was supported by Fundação de Amparo a Pesquisa de Minas Gerais (FAPEMIG) grant # CDS-1881/6. We thank Miss Angela Azor, Prof. Reginaldo dos Santos Pedroso and Mr Celso Tadeu Barbosa dos Santos for their technical support, Mr Henrique Borges Kappel and Mrs Daniela Stefani Marques for their help with the generation of the dendogram and A/Prof. Wieland Meyer for the critical review of this manuscript.

Declaration of interest: The authors report no conficts of interest. The authors alone are responsible for the content and writing of the paper.

This paper was first published online on Early Online on 11 November 2009.