[Identification of Corynebacterium diphtheriae by Way of Immunofluorescence (author's transl)].

The immunofluorescence technique (IF) will be demonstrated as a time-saving method for identifying Corynebacterium diphtheriae. In three test-series the IF-test was performed on 74 strains of C. diphtheriae which had been isolated in a small case of epidemic in Gelsenkirchen, on 4 strains of diphtheroids and on some strains to be found in the nasopharynx. All of these strains had been taken from blood agar, 69 toxinogenic strains of C. diphtheriae showed a clear, plainly reproducible fluorescence (Fig. 1). The diphtheroids and the other strains tested could be clearly differentiated from C. diphtheriae as a consequence of absent fluorescence of the cell wall. Because of morphological changes effected by potassium tellurite on C. diphtheriae smears made from tellurite media proved themselves to be inappropriate for the IF-test. Swabs from carriers of bacilli were not available for our IF-test. The results obtained from the blood agar, however, show that the IF-technique has to be considered as an improvement and a broadening of diphtheria diagnostics. New prospects present themselves for effecting the long aimed-at rapid diagnosis within a few hours.