Objective To evaluate the regulatory role of azithromycin-induced persistent Chlamydia trachomatis (Ct) infection in the apoptosis of Hela229 cells.Methods Hela229 cells were firstly co-cultured with Ct for 22 hours,and then cultured with Dulbecco's modified Eagle's medium (DMEM) containing 0.08 mg/L azithromycin for 26 hours to establish a cell model of persistent Ct infection (persistent infection group).These infected Hela229 cells cultured with azithromycin-free DMEM served as a cell model of acute Ct infection (acute infection group).After 48-hour infection with Ct,azithromycin was removed,and infected Hela229 cells in the above 2 groups were successively cultured with DMEM for the resurgence of Ct.Immunofluorescence assay and electron microscopy were performed to verify the persistent Ct infection model.The Hela229 cells in the persistent infection group and acute infection group as well as uninfected Hela229 cells (control group) were treated with staurosporine (STS) for 4 hours to induce the apoptosis,and then cell apoptosis was detected by Hoechst 33258 staining,annexin V/propidium iodide staining and flow cytometry.Results After the treatment with azithromycin,atypical inclusions with aberrant reticulate bodies appeared in the Ct-infected cells.After removing azithromycin,cells were cultured until 96 hours after infection,and infectious elementary bodies reappeared in the Ct inclusions.After the treatment with STS,Hoechst staining showed that there was loose chromatin in the persistently infected cells,while chromatin condensation was observed in the uninfected cells.After 24-hour infection with Ct and 4-hour induction with STS,the apoptosis rate was significantly higher in the persistent infection group (45.567％ ± 2.631％) than in the acute infection group (38.567％ ± 1.701％,t =2.686,P =0.028),but significantly lower in the persistent infection group than in the uninfected group (69.800％ ± 2.835％,t =8.187,P ＜ 0.001).After 48-hour infection with Ct and 4-hour induction with STS,there was a significant difference in the apoptosis rate between the persistent infection group (46.700％ ± 5.257％) and acute infection group (61.767％ ± 1.815％,t =5.781,P ＜ 0.001),as well as between the persistent infection group and the uninfected group (68.667％ ± 3.156％,t =7.421,P ＜ 0.001).Conclusion This study showed that azithromycin-induced persistent Ct infection regulated the apoptosis of host cells,and this effect lasted 48 hours.

Objective To assess the prevalence of mycoplasma genitalium(MG)in patients attending sexually transmitted disease(STD)clinic in Guangzhou,and to provide an epidemiological foundation for clinical treatment and laboratory diagnostics.Methods Utilizing real-time polymerase chain reaction(PCR),we analyzed MG DNA in 2,749 clinical specimens collected from 2,722 outpatients in the Dermatology Hospital of Southern Medical University from July 2019 to December 2021.Concurrent testing for MG,Chlamydia trachomatis(CT),and Neisseria gonorrhoeae(NG)was performed on 2,382 of these specimens.Patient data extracted from medical records were used to investigate the correlation between STD symptoms and MG infection.Results The investigation revealed that the overall prevalence of MG infection was 4.4%among the sampled patients(120 out of 2,722),with a higher prevalence in males(4.9%,or 87 out of 1,790)compared to in females(3.5%,or 33 out of 932).Notably,the prevalence decreased with increasing age.The highest incidence of MG infection was observed in females aged 18～25 years(6.4%,or 18 out of 281),while the lowest was in males aged 46 years and above(1.5%,or 5 out of 342),showing a statistically significant variation across age groups(P<0.05).Among males with urethritis symptoms,MG positive rate was significantly higher at 7.3%(42 out of 574).The rate of single MG infection was prominent,accounting for 89.9%(71 out of 79)in MG-positive male patients and 61.5%(16 out of 26)in MG-positive female patients.Co-infection rate of MG with CT was 1.2%in females and 0.3%in males,indicating a significant dif-ference(P<0.05).Conclusion The findings suggest a relatively high prevalence of MG infection and co-infection with CT among STD clinic attendees in Guangzhou,particularly in the younger demographic.The study underscores the need for early screening and vigilant surveillance of MG to mitigate its transmission among sexually active popula-tions at high risk.