Identification by Random Amplification of Polymorphic DNA of a Common Molecular Type of Cryptococcus neoformans var. neoformans in Patients with AIDS or Other Immunosuppressive Conditions

Abstract

Sixty clinical isolates of Cryptococcus neoformans var. neoformans were analyzed by random amplification of polymorphic DNA (RAPD) using 12- to 22-mer primers in pairs. Five major profiles, which clearly distinguished between serotypes A (profiles I-III), AD (profile IV), and D (profile V), were identified. Forty-two of 58 serotype A isolates were assigned to profile I, 13 to profile II, and 3 to profile III. Profile I compromised 5 subtypes (profiles Ia-Ie), with 37 to 42 isolates in profile Ia. Twenty-seven of 28 isolates from patients with AIDS belonged to profile Ia (P<.001), as did 7 of 10 isolates from otherwise immunocompromised patients. Isolates from immunocompetent hosts were broadly distributed (profile I, 8 isolates; profile II, 10 isolates; profile III, 2 isolates). RAPD profiles were independent of body site and geographic origin of isolates. Isolates pairs from 3 patients produced identical profiles. A predominant genetic profile among serotype A strains from AIDS patients has not been reported previously.

Variability of karyotypes and RAPD types in genetically related strains of Cryptococcus neoformans

“…In epidemiological studies of the species a considerable variation of karyotypes, DNA-fingerprints, and RAPDgenotypes has been demonstrated (Polacheck and Lebens 1989;Perfect et al 1993;Dromer et al 1994;Wickes et al 1994;Brandt et al 1995Brandt et al , 1996Varma et al 1995;Chen et al 1996). The genetic make-up of the varieties neoformans and gattii was also found to differ from each other (Wickes et al 1994;Varma et al 1995;Boekhout et al 1997).…”

Molecular Typing of Cryptococcus neoformans: Taxonomic and Epidemiological Aspects

“…neoformans, but the two varieties can cause similar neurological syndromes. To diagnose clinical infections and monitor dispersion of strains, technical instruments for cryptococcal genome scanning have been developed (6,8,9,12,29,36,43,44,50,51). Molecular typing techniques have revealed that there is considerable genetic heterogeneity within the species (51,54).…”

Molecular diversity of serial Cryptococcus neoformans isolates from AIDS patients in the city of São Paulo, Brazil

“…Variations in intensity of RAPD-PCR bands were observed, in spite of standardization of DNA concentrations. In this case, the number and reproducibility of the bands were considered independent of the intensity of band (Chen et al 1996).…”

“…The molecular methods contributed for identifying genetic differences among C. neoformans varieties (Currie et al 1994, Barchiesi et al 1995, Chen et al 1996, Klepser & Pfaller 1998, Meyer et al 1999, Calvo et al 2001, García-Bermejo et al 2001, Litvintseva et al 2006, Almeida et al 2007). Some studies suggested that the majority of cases are due to persistence of the original infecting strain, while others suggested that the infections may result from acquisition of new strains.…”

“…Some studies suggested that the majority of cases are due to persistence of the original infecting strain, while others suggested that the infections may result from acquisition of new strains. Mixed infections are also possible since environmental sites may contain more than one strain (Currie et al 1994, Barchiesi et al 1995, Haynes et al 1995, Chen et al 1996, Sullivan et al 1996, Sukroongreung et al 2001, Barreto de Oliveira et al 2004, Igreja et al 2004, Jain et al 2005. These controversial studies led us to suppose that all situations could occur in patients with different episodes.…”