Use of DNA fingerprinting in an epidemiologic study of outbreak-specific and non-specific strains of group C Neisseria meningitidis.

DNA fingerprints of nine group C isolates of Neisseria meningitidis were obtained by digestion with three restriction endonucleases, BamHI, EcoRI, and HindIII. Identical restriction profiles were displayed by five strains isolated from two patients and three contacts during a localized outbreak of meningococcal disease in the area served by our laboratory. A slight difference, appreciable only in the fingerprints obtained with EcoRI, was observed between these isolates and a sixth one isolated from a clinical case occurring in the same area one year later. In contrast, three additional strains, recently isolated from patients in separate areas in Italy, gave restriction profiles differing strikingly from one another and from those produced by the strains isolated in our area.