Molecular epidemiology of the global and temporal diversity of Candida parapsilosis

Abstract

We examined the global epidemiology of C. parapsilosis and assessed the discriminatory capabilities of restriction fragment length polymorphism (RFLP) and RAPD typing methods. We used EcoRI digestion of cellular DNA to generate RFLP; RAPD analysis on genomic DNA. Band profiles were used to distinguish and group isolates. From 7 diverse geographic areas, 536 isolates obtained over 35 y were placed into 23 RFLP subgroups. Subtype VII-1 was dominant worldwide (82.4% of isolates). Dividing the isolates into VII-1 versus non-VII-1 showed temporal variation for the USA pre-1995 versus post-1995 (p<0.0001) and versus Europe pre-1995 (p<0.0001). Genotype distribution differed among localities (p<0.0001); Mexico was unique (p<0.05) due to the high proportion of non-VII-1. The prevalence of C. parapsilosis RFLP type VII-1 apparently has risen in the USA and current isolates show some variation in distribution of types in some non-USA localities. There were no differences in distribution of types comparing babies versus adults, or bloodstream isolates versus colonizing or environmental isolates. RAPD typing showed 3 major profiles, but was less discriminatory.