Molecular typing of Treponema pallidum strains from patients with neurosyphilis in Pretoria, South Africa.

OBJECTIVE

To evaluate the molecular typing system for Treponema pallidum using cerebrospinal fluid (CSF) specimens obtained from patients with neurosyphilis in Pretoria, South Africa.

METHODS

CSF specimens were collected from 32 men and 18 women with suspected late neurosyphilis. Typing of T pallidum involved PCR amplification and restriction analysis of the tprE, G and J genes and determination of the number of 60 base pair tandem repeats within the arp gene by PCR amplification.

RESULTS

Of 13 typeable specimens, 4 strain types were identified: 2i, 3e, 14a and 17e. Subtype 14a was identified in 7 specimens (53.8%), subtype 3e in 4 specimens (30.7%) and subtypes 17e and 2i in 1 specimen (7.6%) each.

CONCLUSIONS

This study shows that the typing system can be applied to specimens which may contain low numbers of spirochaetes such as CSF.