Oxidase positive bacteria in the human nose incidence and species distribution, as diagnosed by genetic transformation.

By diagnostic application of genetic transformation, the occurrence of oxidase positive bacteria in the human nose cavity was examined. Neisseria catarrhalis and Moraxella nonliqucfaciens were the predominating organisms, being equally frequent and representing 87.3 per cent of 111 oxidase positive isolates. In part of the study, comprising 130 patients, N.catarrhalis was isolated from 16.2 per cent and M. nonliquefaciens from 17.7 per cent of the nose specimens. M. liquefaciens and M. osloensis were isolated only occasionally, whereas the two species M. phenylpyrouvica and M. kingii were not encountered. Ten per cent of the isolates belonged to genus Neisseria in the strict sense. An ecological distinction is thereby indicated between rodshaped moraxellae (e.g., M. nonliquefaciens) and “false neisseriae” (e.g., N. catarrhalis) on the one hand and the “true neisseriae” on the other, with only the former groups having an important habitat in the nose. N. elongata, a rodshaped member of genus Neisseria, was not observed in this location. About 80 per cent of the N. catarrhalis and M. nonliquefaciens strains were competent in genetic transformation.