Correlation of restriction fragment length polymorphism genotyping with internal transcribed spacer sequence, randomly amplified polymorphic DNA and multilocus sequence groupings for Candida parapsilosis.

Epidemiological studies of Candida parapsilosis have been performed by molecular methods. To compare two prominent methods, 29 isolates, typed by multilocus sequence typing (MLST), were typed by restriction fragment length polymorphism (RFLP). Of the 19 proposed Candida parapsilosis sensu stricto isolates [group I by internally transcribed spacer (ITS1) sequence], the most commonly encountered species, 17 were RFLP type VII-1. The species Candida orthopsilosis (eight isolates) and Candida metapsilosis (two isolates) consisted of five and one other RFLP types, respectively; none were VII-1. None of the non-VII-1 types were in more than one ITS group. VII-1 is the most common RFLP type (176/203 in continuing studies), and C. parapsilosis sensu stricto is similarly dominant in other studies, and cannot be subtyped by RFLP or MLST. RFLP subtype VII-1 and C. parapsilosis sensu stricto appear to be nearly identical; C. orthopsilosis, which can be subtyped by MLST, can also be subtyped by RFLP. C. metapsilosis appears rarely.