Epidemiological typing of clinical isolates of Achromobacter xylosoxidans: comparison of phenotypic and genotypic methods

The purpose of this paper is to evaluate the utility of different typing methods for Achromobacter xylosoxidans clinical isolates. Ninety-two blood culture isolates of A. xylosoxidans subsp. xylosoxidans were collected over a 25-month period. The typeability, discriminatory power and reproducibility of commonly used phenotypic and genotypic methods, such as resistotyping, plasmid profiling, whole-cell protein fingerprinting, random amplification of polymorphic DNA (RAPD) and pulsed-field gel electrophoresis (PFGE), were compared. All 92 isolates were typeable by all of the methods used, with comparable reproducibility. PFGE showed the highest discriminatory power (98.9%), but whole-cell protein profiling showed better correlation with epidemiological data without significant loss in discriminatory power (94%). Whole-cell protein profiling is a reliable epidemiological tool for the analysis of A. xylosoxidans; PFGE is the most discriminatory.