Typing of Neisseria meningitidis isolates from patients with invasive disease by molecular analysis of porin genes

Polymerase Chain Reaction-Restriction Fragment Length Polymorphism assay (P CR-RFLP) for porA and porB genes of Neisseria meningitidis was applied to t ype 64 strains isolated from cases of invasive disease in Italy. The techni que was also successfully used on non-viable strains and on cerebrospinal f luid samples from patients with meningococcal meningitis diagnosed by PCR. RFLP patterns were obtained for all strains, including those nontypeable or nonsubtypeable by the serological methods. The results confirmed the usefulness of the PCR-RFLP for porA and porB gene s of Neisseria meningitidis in differentiating strains belonging to the sam e serological type and provided discriminative patterns in the increased pr oportion of non serotypeable/serosubtypeable strains circulating in Italy i n recent years.