Pseudomonas paucimobilis, a new species isolated from human clinical specimens, the hospital environment, and other sources

Abstract

Forty-seven strains of yellow-pigmented, non-fermentative, gram-negative, rod-shaped bacteria isolated from clinical specimens (14 strains), the hospital environment (20 strains), and miscellaneous sources (13 strains) were characterized with respect to 68 phenotypic tests. The results, along with those of the same 68 tests carried out on 51 reference strains that represented species of Pseudomonas and six other genera of gram-negative bacteria, were analyzed by numerical taxonomic methods. Twenty-nine of the 47 yellow-pigmented strains, including two strains of Weaver group IIk, biotype 1, formed a homogeneous phenetic group (within-group similarity: 93.4% S(G)). The group consisted of strictly aerobic, heterotrophic rod-shaped bacteria. Cells were motile by means of a single polar flagellum. Only a few of the cells were actively motile in nutrient broth cultures, so this characteristic was often difficult to demonstrate. The strains were homogeneous in their susceptibilities to antimicrobial agents, and the mean guanine-plus-cytosine content of the deoxyribonucleic acids from 13 of the isolates was 64.9 ± 1.4 mol%. The 29 strains conformed to the general characteristics of the genus Pseudomonas. The reasons for excluding the strains from Xanthomonas are discussed. We consider these strains to represent a new species, for which we propose the name Pseudomonas paucimobilis. The type strain of the new species is CL1/70 (=NCTC 11030). The remaining 18 yellow-pigmented isolates were unclassified except for two strains which corresponded to a Flavobacterium sp. (King group IIb).