Achromobacter

Abstract

The genus Achromobacter is used to describe glucosenonfermenting, gram-negative bacilli with peritrichous ³agella rods that are oxidase-positive, attack carbohydrates aerobically, and do not produce 3-ketolactose from lactose.1 Achromobacter species are straight rods 0.8-1.2 µm and 2.5-3.0 µm with rounded ends.2 Originally classified as Alcaligenes, the Achromobacter was reclassified based on phenotypic characteristics, DNA base comparison, DNA-DNA similarity, and 16S rRNA sequence analysis.3 The present Achromobacter genus contains Achromobacter xylosoxidans (with two subspecies, denitriƒcans and xylosoxindans), Achromobacter ruhlandii, and Achromobacter piechaudii. A. xylosoxindans subsp. denitriƒcans and A. xylosoxindans subsp. xylosoxidans were combined under one species because the rRNA cistrons were indistinguishable by hybridization technique despite DNA-DNA homology values of 30%–35%.4 A. ruhlandii was added to the genus to accommodate the hydrogen oxidizing strains.2 The third species A. piechaudii included isolates from human clinical material and strains originally named Alcaligenes faecalis and "Achromobacter iophagus"4, 5; it was added to the genus as they were shown to be phenotypically and genotypically distinct from the other two species.6.