INTERSPECIES RECOMBINATION IN NATURE - A MENINGOCOCCUS THAT HAS ACQUIRED A GONOCOCCAL PIB PORIN

A vaginal isolate of Neisseria has been reported to resemble Neisseria meningitidis in biochemical characteristics but to react with serolog ical reagents that are specific to the PI porin from Neisseria gonorrh oeae. We have confirmed that this isolate has the biochemical attribut es of a meningococcus and have shown that it clusters among meningococ cal isolates on a dendrogram based on isoenzyme variation within house keeping enzymes from populations of N. meningitidis and N. gonorrhoeae . Furthermore, the sequences of the fbp and adk genes were typical of those of N. meningitidis and were distinct from those of N. gonorrhoea e. However, the porB gene was very similar to the per genes of N. gono rrhoeae isolates that express the PIE class of outer-membrane porin (d iffering from one gonococcal per allele at only a single nucleotide si te), and was clearly distinct from the porB genes of N. meningitidis. The isolate therefore appears to be a typical meningococcus, except th at its porB gene has been replaced with the per gene from a gonococcus .