Sequence basis of the serotyping and subtyping efficiency of URA-A/B PCR in Cryptococcus neoformans and indications for one-way multilocus allelic shift

Abstract

The genetic basis of the molecular subtyping of Cryptococcus neoformans isolates, performed by PCRRFLP and PCR-SSCP methodologies led through sequencing and sequence alignment to the detection of Single Nucleotide Polymorphisms (SNP) with consistent allelic status and a clear direction of allelic shifting within and among the accepted subspecies taxa (varieties and serotypes). The consensus sequence allelic status of the subtyped and serotyped isolates points to the possibility of serotype transition accomplished through a gradual allelic shift. The direction of the shift is from Serotype A to Serotype AD to Serotype D, although it is unknown whether these quantal steps can be taken by the same isolate