Isolation of Aerobic Gram Positive Filamentous Rods from Diseased Gingivae

¹ Baylor University College of Dentistry and Graduate School, Dallas, Texas

Micro-organisms were isolated from 54 strips of human gingival tissue treated by 5-minute immersion in benzalkonium chloride prior to maceration and culturing. Thirty-five strains of Gram positive filamentous rods were isolated from approximately half of the gingivae examined. Colonies of S. mitis, N. catarrhalis, and S. aureus were also present in most of the gingival tissue cultures.

The 35 isolated filamentous forms were divided into four groups based on their colonial and cellular characteristics. In addition, tests were made which included studies of their biochemical properties. The accumulated characteristics of each group were considered in classifying the micro- organisms. The four groups closely resembled previously named micro-organisms. The groups and the number of identified cultures in each group were: Group I—Corynebacterium striatum, eight strains; Group II—Acinomyces naeslundi, nine strains; Group III—Nocardia salivae, seventeen strains; Group IV—Leptotrichia dentium (Bacterionema matruchotoii), one strain.