COMPARISON OF 3 TYPING METHODS FOR CLINICAL AND ENVIRONMENTAL ISOLATES OF ASPERGILLUS-FUMIGATUS

To evaluate procedures used for epidemiologic analysis of outbreaks of aspergillosis, we analyzed a collection of 35 Aspergillus fumigatus i solates using three typing methods: isoenzyme analysis (IEA), random a mplified polymorphic DNA (RAPD) analysis, and restriction endonuclease analysis (REA). Twenty-one isolates were from a single hospital, with four isolates coming from different patients. Three clinical isolates came from a different hospital, and 11 clinical or environmental isol ates were derived from a culture collection. With IEA, the patterns of alkaline phosphatase, esterase, and catalase discriminated nine types . In contrast, 22 types were obtained with five different RAPD primers , and 21 types could be detected with three of these (R108, R151, and UBC90). Restriction endonuclease analysis of genomic DNA, digested wit h either XbaI, XhoI, or SalI, detected 3, 17, and 13 different REA typ es, respectively, and 22 types were identified by combining the data f rom the XhoI and SalI REAs. Twenty-eight types were obtainable with a combination of REA, IEA, and RAPD patterns. Overall, the results point ed to substantial genetic variation among the isolates. Though two iso lates had markedly distinct genotypes, their morphologic features and exoantigens were consistent with their being A. fumigatus. The analysi s will help in planning epidemiologic studies of aspergillosis.