Candida albicans is an important opportunistic fungal pathogen capable of causing fatal systemic
infections in humans. Presently in Malaysia, there is little information available on the genetic
diversity of this organism and trends in behavioural characteristics. In this project, three genotyping
methods: 25S rDNA genotyping, Alternative Lengthening of Telomerase (ALT) sequence typing and
Multi-Locus Sequence Typing (MLST) were applied to study the genetic diversity of strains from
infected hospital in-patients and asymptomatic individuals in the community. The results showed
that, with the 25S rDNA genotyping, as in other parts of the world, the most common genotype
was type A which accounted for approximately 70% of the 111 isolates tested. Further typing with
the ALT sequence showed type 3 to be the most common in the isolates tested. MLST analysis
revealed many possibly novel sequence types, as well as a statistically significant association between
pathogenicity and a group of closely related isolates, most of which were from hospital samples.
Further work on genotypes associated with enhanced virulence will help to clarify the value of
genotyping for clinical and epidemiological investigations.
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