[Multicenter study of the Rosco-Neisseria system for the identification of pathogenic neisserias and Branhamella catarrhalis].

The commercial Rosco-Neisseria system was evaluated in the identification of 228 oxidase-positive Gram-negative diplococci and it was compared with conventional tests. The procedure detects gamma-glutamyl aminopeptidase, ONPG, tributyrin hydrolysis, and sensitivity to the disk of 10 micrograms of colistin. A correct identification was obtained in the 65 strains of Neisseria gonorrhoeae, the 33 of N. meningitidis, the 12 of N. lactamica, and the 56 of B. catarrhalis. The method was also able to discriminate 54 out of the 62 strains of nonpathogenic Neisseria. However, the 7 strains of Neisseria polysaccharea and one strain of N. subflava biovar perflava were erroneously identified as N. gonorrhoeae. None of the latter was superoxol positive in contrast with the 100% of cases of gonococcal strains. The Rosco-Neisseria system is simple and inexpensive but it should be applied on specimens that grow on selective media for gonococci (such as Thayer-Martin and others) and it should be complemented by superoxol test.