CELLULAR FATTY-ACID COMPOSITION AND PHENOTYPIC AND CULTURAL CHARACTERIZATION OF CDC FERMENTATIVE CORYNEFORM GROUP-3 AND GROUP-5

Seventy strains of fermentative, asporogenous, gram-positive coccobaci lli or short rods form two closely related groups which ha ce been des ignated CDC fermentative coryneform groups 3 (32 strains, xylose ferme nters) and 5 (38 strains, xylose nonfermenters). The two taxa are othe rwise similar to each other phenotypically and culturally and by a dis tinctive Staphylococcus-like odor and by cellular fatty acid (CFA) com position. CDC group 3 and CDC group 5 strains have been isolated from clinical sources (blood, abscesses, and wounds but not urine or respir atory specimens) in Canada and the United States and among referrals f rom Belgium, Sweden, and Spain. Coryneform CDC group 3 strains were ph enotypically similar to CDC coryneform group A-3 but were distinguisha ble by their inability to reduce nitrate and by their lack of motility . Coryneform CDC group 5 isolates were phenotypically somewhat similar to Actinomyces viscosus and Rothia dentocariosa, escept that none of this group reduced nitrate. Both CDC groups could be differentiated fr om these similar bacteria by the ability to decarboxylate lysine and o rnithine. The CFA compositions of CDC group 3 and 5 strains were simil ar to each other, were distinctive from those of other coryneforms, an d were of the branched-chain ape. API CORYNE codes mere consistent for both CDC group 3 and CDC group 5 bacteria, suggesting that this metho d could be useful as an identification method.