Children may acquire syphilis as a consequence of nonsexual close contact if family members or caregivers are infected by active syphilis. We described 3 cases of acquired secondary syphilis in Chinese preschool children who contracted the disease from their caregivers to draw attention to the potential for syphilis patients to transmit Treponema pallidum to the children they are caretakers for.

Syphilis caused by Treponema pallidum (T. pallidum) infection is accompanied by inflammatory injury of tissue, and has a worldwide distribution and increasing incidence over the past decade. Tp17 has been reported to be a strong membrane immunogen, and was initially observed to play a role in inflammation during syphilis, reacting intensely with human syphilitic sera. We therefore used recombinant Tp17 (rTp17) as a stimulator in our study. Increasing evidence has demonstrated that microRNA (miRNA)-containing exosomes have emerged as a potential effective therapeutic target for many diseases. However, the biological functions and molecular mechanisms of miR-216a-5p in syphilis pathogenesis remain unknown. Our study first identified dramatically decreased miR-216a-5p in plasma of syphilis patients compared with the healthy control, which was negatively correlated with the expression of inflammatory cytokines, including IL-1β, IL-6, and TNF-α. Moreover, endothelial cells treated with miR-216a-5p-containing exosomes significantly attenuated the rTp17-induced inflammatory response. More importantly, we identified that miR-216a-5p could bind to the 3′-untranslated region (UTR) of Toll-like receptor (TLR) 4 (TLR4), and overexpression of TLR4 largely rescued the miR-216a-5p-mediated suppression of rTp17-induced inflammatory cytokine production and the TLR4-MYD88 signaling pathway. Thus, our results reveal a novel role of miR-216a-5p-containing exosomes in endothelial cells, implying a potential therapeutic target for inflammation in syphilis patients.

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The in vitro effects of spectinomycin and ceftriaxone, alone or in combination with erythromycin, ofloxacin, and doxycycline, against Chlamydia trachomatis were investigated by the checkerboard method and compared by Ridit (reference identical unit) analysis. A combination of spectinomycin with erythromycin or doxycycline was found to be more effective than that of ceftriaxone.