MAMA Real-Time PCR Assay Panel for Genotyping Cyrptococcus gattii


Researchers at TGen and Northern Arizona University (NAU) have developed methods for genotyping Cryptococcus gattii using a mismatch amplification mutation assay (MAMA) real-time PCR assay panel.  This assay panel provides a rapid method for genotyping of C. gattii molecular types VGI-VGIV and the dominate North American VGII molecular subtypes VGIIa-c with high sensitivity and specificity to better understand the genotype distribution of C. gattii in a geographic area.


Cryptococcus species are the source of many serious fungal diseases, some of which are potentially fatal (e.g., Cryptococcosis).  Cryptococcus gattii in particular has been responsible for outbreaks in Canada and the Pacific Northwest of the United States, with some outbreaks being attributed to novel genotypes and subtypes.  Given the increased virulence, varying antifungal susceptibilities and clinical outcomes caused by these genotypes, as compared to other C. gattii genotypes, regular genotyping of C. gattii isolates is useful for both clinical and epidemiological response purposes.  Current methods for genotyping C. Gattii include PCR-restriction fragment length polymorphism (PCR-RFLP), amplified fragment length polymorphism (AFLP), multilocus microsatellite typing (MLMT), multilocus sequence typing (MLST), and matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS); however many of these methods require extensive lab work, expensive equipment, or produce results that are not readily transferrable between laboratories.


The allele specific assay panel developed by TGen and NAU runs on real-time PCR equipment that is becoming increasingly accessible and produces easily transferrable results for relatively low cost.  Samples used with this method may be derived from the environment or from subjects, such as humans and animals.  Additionally, new subtype specific assays can be developed using these methods as the understanding of C. Gattii populations and genotype-phenotype relationships is furthered through research around the globe.



Link to US Issued Patent No. 9,994,917

Patent Information:
For Information, Contact:
Katie Bray
Intellectual Property Counsel
The Translational Genomics Research Institute
David Engelthaler
Elizabeth Driebe
Erin Kelley
Paul Keim