Journal of Clinical Microbiology, April 2002, p. 1210-1213, Vol. 40, No. 4
0095-1137/02/$04.00+0     DOI: 10.1128/JCM.40.4.1210-1213.2002
Copyright © 2002, American Society for Microbiology. All Rights Reserved

The taxonomy of the genus Alcaligenes has undergone a number of changes during the last 20 years. The
species Achromobacter (Alcaligenes) xylosoxidans has consecutively been named Achromobacter
xylosoxidans, Alcaligenes denitrificans subsp. xylosoxidans, and Alcaligenes xylosoxidans subsp.
xylosoxidans (26). More recently, the name Achromobacter xylosoxidans was again proposed (31).

A. xylosoxidans is an aerobic, oxidase- and catalase-positive, non-lactose-fermenting, gram-negative
bacillus that is widely distributed in the natural environment. It is an opportunistic human pathogen capable
of causing a variety of infections, including bacteremia, meningitis, pneumonia, and peritonitis (4, 5, 7, 14,
28). Nosocomial outbreaks attributed to disinfectant solutions, dialysis fluids, saline solution, and deionized
water contaminated with this species have been described (8, 9, 19, 24, 25, 27).

A. xylosoxidans is also capable of persistent infection of the respiratory tract of persons with cystic fibrosis
(CF) (2, 6, 22), although its precise role in contributing to pulmonary decline in this population is not clear.
Nevertheless, this species is important in CF; it infects some 9% of CF patients (2) and is frequently
confused with species within the Burkholderia cepacia complex (1, 20). Infection with these latter species is
associated with significantly increased rates of morbidity and mortality in CF, and stringent infection control
efforts are employed to prevent infection (16). Misidentification of A. xylosoxidans and related nonfermenting
species seriously compromises infection control measures and confounds efforts to more clearly understand
the epidemiology and natural history of infection in CF. To enable more accurate identification of A.
xylosoxidans, we developed PCR assays based on 16S rRNA gene sequences.