Growth characteristics and a novel method for identification (the WEE- TAB system) of Porphyromonas species isolated from infected dog and cat bite wounds in humans

Abstract

Thirty-nine clinical isolates of Porphyromonas species recovered from infected cat and dog bite wounds in humans and eight American Type Culture Collection and National Collection of Type Cultures type strains were characterized by using the API ZYM system, the RapID ANA II system, and conventional biochemical methods. Growth characteristics on various agar media were compared. All strains grew on brucella blood agar supplemented with vitamin K1 and hemin and on brucella laked blood agar supplemented with vitamin K1 and heroin. In contrast, only 34% of strains grew on unsupplemented brucella blood agar, 62% grew on Columbia blood agar, and 70% grew on tryptic say blood agar (the last three media did not contain vitamin K1 or hemin). The ability of the single-tube, triple-substrate WEE-TAB system to detect the preformed enzymes N-acetyl-βD-glucosaminidase, α-D- galactosidase, β-D-galactosidase, α-fucosidase, trypsin-like activity, and chymotrypsin was evaluated. The WEE-TAB test results were easy to interpret; the WEE-TAB tests were more sensitive than the comparable tests with the API ZYM and RapID ANA II systems for the detection of α-D-galactosidase, β-D- galactosidase, trypsin, and chymotrypsin, and the WEE-TAB tests accurately identified Porphyromonas species.