TYPING OF NEISSERIA-MENINGITIDIS BY RESTRICTION ANALYSIS OF THE AMPLIFIED PORA GENE

We tested a typing system for 54 isolates of Neisseria meningitidis us ing polymerase chain reaction (PCR) amplification of the porA gene, Th e isolates were obtained between 1989 and 1994 from cases in Western A ustralia and Sydney, The PCR product was digested by five restriction endonucleases (AluI, HaeIII, HinfI, RsaI and HpaII) giving a restricti on fragment length polymorphism (RFLP) pattern for each isolate, All o f the isolates were able to be assigned an RFLP pattern, whereas 24 co uld be fully serotyped and serosubtyped. The method was rapid and simp le to perform and results were easy to interpret. Two outbreaks of inv asive meningococcal disease were included in the analysis, one involvi ng an hyperendemic focus of disease and the other characteristic of a point outbreak. The typing system demonstrated the genetic relatedness of isolates from the point outbreak and the genetic diversity among t he hyperendemic strains, We conclude that the method is discriminatory and is a useful supplement to serological typing for studying Austral ian outbreaks of invasive meningococcal disease.