GENETIC-STRUCTURE OF NEISSERIA-GONORRHOEAE POPULATIONS - A NON-CLONALPATHOGEN

Reproduction by binary fission generates a clonal genetic structure in bacterial populations in the absence of a high rate of recombination. The extent of recombination in natural populations of Neisseria gonor rhoeae was determined from an analysis of electrophoretically demonstr able allelic variation at structural genes encoding nine enzyme loci i n 227 worldwide isolates. No significant linkage disequilibrium was ev ident in the population, indicating that recombination must be frequen t, relative to binary fission. The genetic structure of N. gonorrhoeae was compared with that of Bacillus subtilis from an earlier study. Li nkage disequilibrium was less extreme in the N. gonorrhoeae population than in the local population of B. subtilis, in which only modest clo nal structure was evident. Thus, N. gonorrhoeae, unlike pathogens so f ar examined, has a non-clonal population structure. As expected in a f reely recombining population, no correlation was found between electro phoretic genotype and serovar or auxotype.