Application of gas-liquid chromatography to the routine identification of nonfermenting gram-negative bacteria in clinical specimens

Abstract

A total of 430 strains of glucose-nonfermenting gram-negative bacteria representing 35 species were analyzed for their cellular fatty acid composition by gas-liquid chromatography (GLC). On the basis of qualitative differences in their cellular fatty acid composition, these bacteria could be divided into 19 distinct chromatographic groups. Eight Pseudomonas species, Achromobacter xylosoxidans, group Vd, and Agrobacterium radiobacter were identified from their fatty acid compositions alone. The other glucose-nonfermenting gram-negative bacterial species studied here, classified within nine distinct GLC groups, were easily recognized by using the GLC fatty acid analysis supplemented with a limited number of conventional biochemical tests. The results support the hypothesis that bacterial fatty acid composition is rather specific and that qualitative GLC fatty acid analysis can be adapted in the clinical laboratory either to provide additional criteria for differentiation of closely related groups or to serve as a rapid and highly reproducible method for their routine identification.

Biochemical and chemotaxonomic characterization of Pseudomonas stutzeri genomovars

“…stutzeri genomovars were homogeneous, ,showing a high degree of similarity for all strains. The results are congruent with those reported previously (Veys et al 1989;Stead 1992). A differentiation of Ps.…”

“…All strains were characterized by large amounts of 16 : 0 (hexadecanoic acid), 16 : 1 (cis-9 hexadecenoic acid) and 18 : 1 (cis-9 octadecenoic acid) in addition. to minor amounts of the hydroxylated fatty acids 3-013 10 : 0 (3hydroxy decanoic acid) and 3-OH 12 : 0 (3-hydroxy dodecanoic acid), which is in good agreement with published data (Veys et al 1989;Stead 1992). Only minor pattern differences were found between the genomovars, although genomovar 6 strains showed a higher content of cis 9,lO methylenehexadecanoate (17 : Oc) and cis 9 , l O methyleneoctadecanoate (19 : Oc) than strains of the other genomic groups (Table 1).…”

“…alcaligenes and Ps. pseudoalcaligenes may also be difficult (Veys et al 1989). However, a clear separation of Ps.…”

Lipids and fatty acids of Burkholderia and Ralstonia species

“…Also contains 16 :1 (NCIMB 40529, 4%; NCIMB 11842, 6%). acids has also been described for some strains of R. pickettii [20,21] but not the type strain [4,5], and again there are con£icting reports for R. eutropha [5,18]. In neither Ralstonia species did the LPS contain 2-OH-18:1 which is present in R. solanacearum [29,30], together with 3-OH-14:0, the only LPS-spe-ci¢c hydroxy acid [4,5,10,24].…”

“…In a further strain of R. pickettii (A93/71), 2-OH-16:0 was present in place of 2-OH-14:0. The absence of 3-OH-16:0 from the cellular fatty acids has been reported for both R. pickettii [4,5,20,21] and the type strain of R. eutropha [18], although a contradictory claim has been made for the latter [5]. The presence of 2-OH-14:0 (which should not be derived from PE2 or OL2 [3,4]) among the cellular fatty Data are expressed as percentages of the total peak area on GLC of the methyl esters.…”