Molecular methods for the diagnosis and characterization of Cryptococcus: a review.
Cryptococcosis is a fungal infection caused by yeasts of the genus Cryptococcus, with Cryptococcus neoformans and Cryptococcus gattii as the primary pathogenic species. This disease is a threat to immunocompromised patients, especially those who have AIDS. However, the disease has also been described in healthy individuals. The tests used to identify these microorganisms have limitations that make final diagnosis difficult. However, currently there are specific gene sequences that can be used to detect C. neoformans and C. gattii from clinical specimens and cultures. These sequences can be used for identification, typing, and the study of population genetics. Among the main identification techniques are hybridization, which was the pioneer in molecular identification and development of specific probes for pathogen detection; PCR and other PCR-based methods, particularly nested PCR and multiplex PCR; and sequencing of specific genomic regions that are amplified through PCR, which is especially useful for diagnosis of cryptococcosis caused by unconventional Cryptococcus sp. Concerning microorganism typing, the following techniques have shown the best ability to differentiate between fungal serotypes and molecular types: PCR fingerprinting, PCR-RFLP, AFLP, and MLST. Thus, the accumulation of data generated by molecular methods can have a positive impact on monitoring resistant strains and treating diseases.
Sidrim
José Júlio Costa
JJ
Specialized Medical Mycology Center, Federal University of Ceará, Rua Coronel Nunes de Melo, Rodolfo Teófilo, Fortaleza, Ceará, Brazil.
Costa
Ana Karoline Freire
AK
Cordeiro
Rossana Aguiar
RA
Brilhante
Raimunda Sâmia Nogueira
RS
Moura
Fernanda Edna Araújo
FE
Castelo-Branco
Débora Souza Collares Maia
DS
Neto
Manoel Paiva de Araújo
MP
Rocha
Marcos Fábio Gadelha
MF
D003453:Cryptococcosis / Q000175:diagnosis*; D003454:Cryptococcus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D016172:DNA Fingerprinting / Q000379:methods; D004271:DNA, Fungal / Q000235:genetics; D006801:Humans; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D016533:Mycological Typing Techniques; D009172:Mycology / Q000379:methods*
D004271:DNA, Fungal