Ligang Yang

Background: Recovering clinical isolates of Treponema pallidum (Tp) can expedite the research on molecular epidemiology and vaccine development of syphilis. Nevertheless, obtaining numerous isolates through rabbit infectivity testing remains unsatisfactory, particularly in secondary syphilis cases. This study re-evaluates the reliability of orchitis as a phenotypic indicator for assessing Tp clinical strains during rabbit infectivity testing. Methods: Treponemal and nontreponemal tests were used to analyze the correlation between serological titers and Tp burden. An optimal titer threshold was identified and applied to verify the maximum achievable Tp burden across different initial inoculation doses. A modified recovery protocol was developed for isolating Tp clinical strains from chancre exudates or whole blood, and its success rate was subsequently evaluated. Results: We demonstrated that a Tp particle agglutination titer of 1:1280 reliably indicated the peak burden of Tp Nichols strain and clinical isolates during rabbit infectivity testing. To achieve stable recovery, the initial inoculum should be at least 105 organisms. Using this optimized protocol, we successfully recovered and maintained Tp clinical isolates from 82.69% (43/52) of syphilis patients overall. Notably, the success rate from whole blood samples of secondary syphilis cases increased markedly to 82.50% (33/40) despite many of these specimens testing negative for Tp DNA by quantitative polymerase chain reaction. Conclusions: This study shows that the pathogenicity of secondary syphilis blood is greater than previously recognized. Thus, monitoring Tp particle agglutination titers enables the recovery of Tp clinical isolates, even from specimens with extremely low bacterial burdens.

Background: Consistent evidence shows stigma impedes healthcare access in people living with HIV (PLWH) and men who have sex with men (MSM). We evaluated the impact of stigma reduction training for providers whose design was informed by direct observation of their clinical behaviors obtained through visits by incognito standardized patients (SPs). Setting: We conducted this study in sexually transmitted disease clinics in Guangzhou, China. Methods: This pilot cluster randomized control trial assessed the feasibility, acceptability, and preliminary efficacy of an intervention whose design was informed by a baseline round of incognito visits in which SPs presented standardized cases to consenting doctors. By randomly varying the HIV status and sexual orientation of each case, we could quantify stigma as differences in care quality across scenarios. We then conducted a follow-up round of SP visits and assessed the impact using linear fixed effects regression. Results: Feasibility and acceptability among the 55 provider participants were high, with no adverse visit events. The provider training improved the offering of testing to HIV-negative MSM (0.05 percentage points, 95% confidence interval, −0.24 to 0.33) and diagnostic effort for HIV-positive MSM (0.23 SD improvement, 95% CI: −0.92 to 1.37). Patient-centered care only improved for HIV-positive straight cases (SD, 0.57; 95% CI: −0.39 to 1.53). All estimates lacked statistical precision, an expected outcome of a pilot randomized control trial. Conclusions: Our training reduced stigma in several domains of care, but least of all for PLWH, suggesting that future trainings should include more clinical content to strengthen clinical skills in PLWH management.

Syphilis is a chronic, systemic sexually transmitted disease (STD) caused by the Treponema pallidum (T. pallidum). It is one of the most prevalent STDs in the world. In the United State, the cases ...

Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) infections are prevalent among men who have sex with men (MSM) in China. However, compared to syphilis and HIV, the testing rate for chlamydia and gonorrhea remains low. The purpose of this pilot study was to evaluate the feasibility for conducting rapid nucleic acid test for chlamydia and gonorrhea in MSM community-based organizations (CBO). We recruited our participants through an MSM CBO where free HV and syphilis testing were routinely provided. We collected data including social-demographic background, sexual history, chlamydia and gonorrhea testing history, and reasons for accepting this on-site rapid testing. Urine and/or anorectal swab samples were collected and tested for chlamydia and gonorrhea on-site and the testing results were delivered in about 1.5 h. Positive cases received on-site free treatment. From August 2020 to October 2020, 634 MSM visited the CBO for syphilis and HIV testing and 158 (158/634, 24.9%) accepted the on-site chlamydia and gonorrhea rapid test, 135 were finally enrolled. The positive rate fo chlamydia was 16.3% (22/135) and 3.0% (4/135) for gonorrhea, respectively. Only 19.3% participants had previously undergone chlamydia and gonorrhea testing and 68.9% (93/135) participants reported that they had heard of gonorrhea, 47.4% (64/135) had heard of chlamydia. The main reason for testing was “free for charge” (66.2%), followed by “convenient, ‘shorter waiting time” (45.2%) and “had high-risk sexual behavior recently” (16.3%). This pilot study showed that the chlamydia and gonorrhea infection rate remains high among MSM, while the testing rate was low. On-site rapid testing is feasible and potentially preferred by MSM.

Background: Mycoplasma genitalium (MG) causes urogenital tract infections and is associated with reproductive morbidity. Although MG has been reported across many regions and population groups, it is not yet routinely tested for in China. Our study contributes to current research by reporting the prevalence and correlates of MG infection in patients attending a sexually transmitted infection (STI) clinic in Guangdong from Jan 2017-May 2018. Methods: Urethral (from 489 men) and endo-cervical (from 189 women) samples, blood samples, and patient histories (via questionnaires) were collected. Doctors clinically diagnosed anogenital warts (GW) during the examination (n = 678). The presence of MG was evaluated using an in-house via polymerase chain reaction protocol. We also tested all participants for herpes simplex virus-2 (HSV-2), Neisseria gonorrhoeae (NG), Chlamydia trachomatis (CT), syphilis and HIV. Univariate and multivariate logistic regression were used to evaluate factors associated with MG. Results: MG was detected in 7.2% (49/678) of the patients (men, 7.4%; women, 6.9%). The MG positivity rate was 14.2% among symptomatic patients, and 5.6% for asymptomatic patients, respectively. Only 36.7% (18/49) Mg positive patients were symptomatic. Among the MG-infected patients, 10.2% were co-infected with CT, 6.1% with NG, 8.2% with HSV-2, 4.1% with syphilis and 22.4% with GW. Presentation with clinical symptoms was significantly associated with MG infection [OR = 2.52 (2.03–3.13)]. In our analysis, MG was not associated with other STIs. Conclusions: MG is a relatively common infection among individuals attending an STI clinic in Guangdong Province. Routine testing of symptomatic patients may be necessary, and more epidemiological studies are needed to provide evidence for future testing guidelines.

Background: Antimicrobial resistance in M. genitalium is a growing clinical problem. We investigated the mutations associated with macrolide and fluoroquinolone resistance, two commonly used medical regimens for treatment in China. Our aim is to analyze the prevalence and diversity of mutations among M. genitalium-positive clinical specimens in Guangzhou, south China. Methods: A total of 154 stored M. genitalium positive specimens from men and women attending a STI clinic were tested for macrolide and fluoroquinolone mutations. M. genitalium was detected via TaqMan MGB real-time PCR. Mutations associated with macrolide resistance were detected using primers targeting region V of the 23S rRNA gene. Fluoroquinolone resistant mutations were screened via primers targeting topoisomerase IV (parC) and DNA gyrase (gyrA). Results: 98.7% (152/154), 95.5% (147/154) and 90.3% (139/154) of M. genitalium positive samples produced sufficient amplicon for detecting resistance mutations in 23S rRNA, gyrA and parC genes, respectively. 66.4% (101/152), 0.7% (1/147) and 77.7% (108/139) samples manifested mutations in 23S rRNA, gyrA and parC genes, respectively. A2072G (59/101, 58.4%) and S83I (79/108, 73.1%) were highly predominating in 23S rRNA and parC genes, respectively. Two samples had amino acid substitutions in gyrA (M95I and A96T, respectively). Two samples had two amino acid substitutions in parC (S83I + D87Y). 48.6% (67/138) of samples harbored both macrolide and fluoroquinolone resistance-associated mutations. The most common combination of mutations was A2072G (23S rRNA) and S83I (parC) (40/67, 59.7%). One sample had three amino acid changes in 23S rRNA, gyrA and parC genes (A2072G + A96T + S83I). Conclusions: The high antimicrobial resistance rate of M. genitalium in Guangzhou is a very worrying problem and suggests that antimicrobial resistance testing and the development of new antibiotic regimens are crucially needed.

Background Antimicrobial resistance in M. genitalium is a growing clinical problem. We investigated the mutations associated with macrolide and fluoroquinolone resistance, two commonly used medical regimens for treatment in China. Our aim is to analyze the prevalence and diversity of mutations among M. genitalium-positive clinical specimens in Guangzhou, south China.Methods A total of 154 stored M. genitalium positive specimens from men and women attending a STI clinic were tested for macrolide and fluoroquinolone mutations. M. genitalium was detected via TaqMan MGB real-time PCR. Mutations associated with macrolide resistance were detected using primers targeting region V of the 23S rRNA gene. Fluoroquinolone resistant mutations were screened via primers targeting topoisomerase IV (parC) and DNA gyrase (gyrA).Results 98.7% (152/154), 95.5% (147/154) and 90.3% (139/154) of M. genitalium positive samples produced sufficient amplicon for detecting resistance mutations in 23S rRNA, gyrA and parC genes, respectively. 66.4% (101/152), 0.7% (1/147) and 77.7% (108/139) samples manifested mutations in 23S rRNA, gyrA and parC genes, respectively. A2072G (59/101, 58.4%) and S83I (79/108, 73.1%) were highly predominating in 23S rRNA and parC genes, respectively. Two samples had amino acid substitutions in gyrA (M95I and A96T, respectively). Two samples had two amino acid substitutions in parC (S83I + D87Y). 48.6% (67/138) of samples harbored both macrolide and fluoroquinolone resistance-associated mutations. The most common combination of mutations was A2072G (23S rRNA) and S83I (parC) (40/67, 59.7%). One sample had three amino acid changes in 23S rRNA, gyrA and parC genes (A2072G + A96T + S83I).Conclusions The high antimicrobial resistance rate of M. genitalium in Guangzhou is a very worrying problem and suggests that antimicrobial resistance testing and the development of new antibiotic regimens are crucially needed.