Evaluation of the rapid CORYNE identification system for Corynebacterium species and other coryneforms

Abstract

The Rapid CORYNE system for identification of aerobic, nonsporeforming, gram-positive rods was evaluated according to the manufacturer's instructions with 177 organisms. After inoculation with a heavy suspension of growth, strips containing 20 cupules were incubated for 24 h, reagents were added, and the results of 21 biochemical reactions were recorded as numerical profiles. The strains consisted of pathogenic species of the genus Corynebacterium, primarily C. diphtheriae (n = 29), opportunistic species of Corynebacterium including C. jeikeium (n = 75), recognized species of non-corynebacteria such as Gardnerella and Arcanobacterium (n = 51), and Centers for Disease Control (CDC) coryneform groups (n = 22). Results from single tests read after 24 h yielded correct identifications to species level with no additional tests for 26 (89.7%) of the pathogenic species; 64 (85.3%) of the opportunistic organisms; 51 (100%) of the non-corynebacteria, and 8 (36.4%) of the CDC coryneform groups. Supplemental tests produced the correct identification for three additional pathogenic isolates (100% total) and four additional isolates from the opportunistic species (90.6% total). Twelve of the 15 isolates not identified by the system were in the CDC coryneform groups. Four of the six misidentified and one of the unidentified isolates were C. matruchotii, which was not included in the data base. The system is an excellent rapid alternative to conventional biochemical tests.