Organization of the ribosomal operon 16S-23S gene spacer region in representatives of Neisseria gonorrhoeae

Ribosomal rRNA gene fragments (rDNA) encompassing part of the 16S rDNA, the 16S-23S rDNA spacer region and parr of the 23S rDNA of 229 Neisseria gonor rhoeae strains were enzymatically amplified using conserved primers. The fr agments of approximately 1200 bp were subjected to restriction analysis wit h Hinf1. This revealed 13 patterns (patterns I-XIII) of which patterns I (7 8 strains), II (32 strains), III (38 strains) and IV (56 strains) were the most abundant, comprising 89.1% of the strains. The obtained restriction pa tterns consisted of 3 to 8 bands, ranging in size from 32 to 854 bp. The su m of the obtained bands was about 1200 bp for patterns I, II, III, IV, V, I X, and XIII. However, for patterns VI, VII, VIII, X, XI and XII, the sum of the bands well exceeded the estimated size of approximately 1200 bp. We de monstrated that this results from sequence divergence in the 4 rRNA operons , present in the genome of N. gonorrhoeae, giving rise to patterns that are a combination of several other patterns.