Use of VNTR typing to test genetic diversity of Neisseria gonorrhoeae isolates

Variable number tandem repeats (VNTRs) have been identified in silico by the present study in the Neisseria gonorrhoeae genome. Using a collection of 48 N. gonorrhoeae isolates derived from patients with gonorrhea in Almaty (Kazakhstan), the identified VNTR loci have been studied for the possibility of applying them for VNTR typing and compared to opa typing. The Hunter-Gaston discrimination index (HGDI) for VNTR typing on two loci (VNTR2048 and NMTR-12) was 0.734, which is lower than HGDI for opa typing (0.959). The VNTR1192-locus has a complex structure based on repeated elements, which created difficulties for its electrophoretic analysis. However, the analysis of the nucleotide sequence of this locus allows one to differentiate between all 48 isolates that participate in the study. The proposed VNTR loci can be used to analyze gonorrhea transmission through sexual contact and solve other molecular and epidemiological problems.