Fatty acids of Gram-positive bacterial rods from human dental plaque

Cellular fatty acid composition as an adjunct to the identification of asporogenous, aerobic gram-positive rods

Cellular fatty acid (CFA) compositions of 561 asporogenous, aerobic gram-positive rods were analyzed by gas-liquid chromatography as an adjunct to their identification when grown on blood agar at 35 degrees C. The organisms could be divided into two groups. In the first group (branched-chain type), which included coryneform CDC groups A-3, A-4, and A-5; some strains of B-1 and B-3; "Corynebacterium aquaticum"; Brevibacterium liquefaciens; Rothia dentocariosa; and Listeria spp., the rods had sizable quantities of antiesopentadecanoic (Ca15:0) and anteisoheptadecanoic (Ca17:0) acids. Other species with these types of CFA included B. acetylicum, which contained large amounts of isotridecanoic (Ci13:0) and anteisotridecanoic (Ca13:0) acids. CFAs useful for distinguishing among Jonesia denitrificans, Oerskovia spp., some strains of CDC groups B-1 and B-3, Kurthia spp., and Propionibacterium avidum were hexadecanoic (C 16:0) acid, isopentadecanoic (Ci15:0) acid, and Ca15:0). The second group (straight-chained type), which included Actinomyces pyogenes; Arcanobacterium haemolyticum; C. bovis; C. cystitidis; C. diphtheriae; C. flavescens, "C. gentalium"; C. jeikeium; C. kutscheri; C. matruchotii; C .minutissimum; C. mycetoides; C. pilosum; C. pseudodiphtheriticum; "C. pseudogenitalium"; C. pseudotuberculosis; C. renale; CDC groups 1, 2, ANF-1, D-2, E, F-1, F-2, G-1, G-2, and I-2; C. striatum; "C. tuberculostearicum"; C. ulcerans; C. vitarumen; C. xerosis; and Erysipelothrix rhusiopathiae, was typified by significant quantities of hexadecanoic (C16:0) and oleic acids (C18:cis9), with differences in the amounts of linoleic acid (C18:2), stearic acid (C18:0), an unnamed peak (equivalent chain length, 14.966), and small quantities of other known saturated and unsaturated fatty acids. CFA composition of these organisms was sufficiently discriminatory to assist in classification but could not be used as the sole means of identification.

Lipid and wall amino acid composition in the classification and identification of Arachnia propionica

Two strains of Arachnia propionica and two Arachnia-like isolates were degraded by alkaline methanolysis and the non-hydroxylated fatty acid esters released were examined by thin-layer and gas chromatography. The fatty acid profiles obtained were both qualitatively and quantitatively similar and were comprised of iso-, anteiso- and straight chain saturated fatty acids with 13-methyltetradecanoic acid (i-15) and 12-methyltetradecanoic acid (ai-15) as major components. One of the Arachnia-like strains (HIK 288) had, in addition to i-15 and ai-15, major amounts of pentadecanoic acid (15:0). All of the strains gave characteristic polar lipid patterns consisting of diphosphatidylglycerol, phosphatidylglycerol and two incompletely characterised glycolipids. Analyses of wall amino acid preparations by gas and thin-layer chromatography showed that Arachnia propionica strains contain major amounts of alanine, glycine, glutamic acid and LL-diaminopimelic acid. The chemical data support the integrity of Arachnia propionica and provide a valuable means of differentiating it from morphologically and physiologically similar strains of Actinomyces israelii.