Molecular detection ofT. pallidumby PCR in seronegative cases

For the molecular detection of Treponema pallidum authors introduced and used a nested PCR amplifying a conservative portion of the gene coding for the Tp 47 kDa membrane protein. PCR verified the presence of T. pallidum specific DNA in 5.7 per cent of syphilis seronegative 105 MSM belonging to HIV risk group. Treponema DNA was also detected in HIV infected, syphilis seronegative cases. Specificity of the method was demonstrated in rabbit inoculation test and also in clinically positive syphilis cases.