Objective To evaluate the relationship between spectinomycin resistance in Neisseria gonorrhoeae and mutations in the rpsE gene.Methods Genomic DNA was extracted from 4 clinical isolates of Neisseria gonorrhoeae with different levels of spectinomycin resistance.Then,PCR was performed to amplify the entire rpsE gene and the spectinomycin resistance-determining region (SRDR) in the 16S rRNA gene followed by direct sequencing.Two spectinomycin-sensitive Neisseria gonorrhoeae strains were transformed with the genomic DNA containing the mutant rpsE gene.Subsequently,the susceptibility of the transformants to spectinomycin was determined,and PCR was performed to amplify the rpsE and 16S rRNA genes in the transformants followed by sequencing.Results All the 4 spectinomycin-resistant Neisseria gonorrhoeae strains harbored an A70C transversion in the rpsE gene,but no abnormality in the SRDR of the 16S rRNA gene.No mutations were detected in the spectinomycin-sensitive Neisseria gonorrhoeae strains.The A70C transversion in the rpsE gene was also detected in the two Neisseria gonorrhoeae transformants with spectinomycin resistance.Conclusion The A70C point mutation within the rpsE gene is associated with spectinomycin resistance in Neisseria gonorrhoeae.

Objective To investigate the serovar distribution of Chlamydia trachomatis (Ct) isolated from male patients with urethritis in sexually transmitted disease (STD) clinic.Methods Urine specimens were collected from male patients with urethritis in STD clinic at Hospital of Dermatology,Chinese Academy of Medical Sciences between January 2013 and December 2013.Fluorescence-based quantitative PCR was performed to detect Ct DNA in these specimens.DNA was extracted from Ct-positive urine specimens,and nested PCR was conducted to amplify the VS1-VS2 regions of the outer membrane protein A (ompA) gene,followed by gene sequencing.The resulting sequences were aligned to reference sequences by the DNAStar5.0 software to determine Ct serovars.Results A total of 432 urine specimens were collected,and 33.1％ (143/432) of them were positive for Ct.The VS1-VS2 regions of the ompA gene were amplified from 127 out of the 143 Ct-positive specimens,but not from the other 16 specimens.Nine serovars were identified by gene sequencing among the 127 specimens,including serovar E (29 strains,22.83％),F (28 strains,22.05％),D (19 strains,14.96％),G (16 strains,12.60％),J (16 strains,12.60％),K (8 strains,6.30％),H (5 strains,3.94％),I (3 strains,2.36％) and B (3 strains,2.36％),and Ct serovars E,F,D,J and G accounted for 85.02％ among all the strains.Synonymous mutations were identified in 14 out of the 127 strains when compared with reference strains.Conclusions E,F,D and G serovars were the main Ct serovars in male patients with urethritis in STD clinic.The proportion of Ct serovar E strain was decreased,but that of serovar J strain was increased compared with 20 years ago.

Objective To establish two nested PCR assays for detection of Trichomonas vaginalis in urine samples from male patients with urethritis,and to evaluate their diagnostic value.Methods One thousand and eighty-eight male patients with urethritis were enrolled from sexually transmitted disease (STD) clinic in the Hospital of Dermatology,Chinese Academy of Medical Sciences and Peking Union Medical College between April 2011 and December 2013.Urethral swabs were collected followed by smear testing,wet mount microscopic examination of Trichomonas vaginalis,and cultivation of Neisseria gonorrhoeae.Urine specimens were also obtained from these patients followed by DNA extraction.Two nested PCR assays were developed and performed to amplify the repeat genomic sequence and β-tubulin gene of Trichomonas vaginalis.Results Trichomonas vaginalis was detected in none of these swab specimens by wet mount microscopy,but in 29 (2.67％) of the urine specimens by either of the two nested PCR assays.Moreover,the positive specimens detected by the two nested PCR assays were completely consistent.Conclusion Compared with wet mount microscopy,nested PCR has higher sensitivity and specificity in detection of Trichomonas vaginalis in urine samples from male patients.

Objective To investigate DNA methylation markers in the whole blood of patients with systemic lupus erythematosus(SLE),in hope to facilitate the evaluation of SLE severity.Methods Whole blood samples were obtained from 58 patients with SLE(including 14 cases of severe SLE,25 moderate SLE,19 inactive SLE)and 50 healthy controls.Bisulphite sequencing was performed to determine the methylation status of interleukin-2 common receptor gamma chain(IL-2RG)promoter region,and real-time reverse transcriptionPCR to quantify the expression level of IL-2RG mRNA,in these subjects.Results The methylation level of IL2RG promoter region was 0.217 ± 0.140,0.325 ± 0.230,0.342 ± 0.085 and 0.175 ± 0.036 in the patients withsevere,moderate and inactive SLE and healthy controls,respectively.A significant increase was observed in the methylation level of IL-2RG promoter region in the patients with inactive SLE compared with the patients with severe SLE and healthy controls(both P ＜ 0.01),and in the patients with SLE compared with the healthy controls(0.263 ± 0.047 vs.0.175 ± 0.036,P ＜ 0.05).The expression level of IL-2RG mRNA was significantly lower in the patients with SLE than in the healthy controls(2.550 ± 0.823 vs.4.293 ± 1.283,P ＜ 0.05).A negative correlation was observed between the expression level of IL-2RG mRNA and methylation level of IL2RG promoter region in 20 patients with SLE(r =-0.44,P ＜ 0.05).Conclusion The methylation status of IL2RG promoter region is statistically higher in patients with SLE than in healthy controls,and significantly different between patients with active SLE and those with stable SLE.

Objective:To investigate outcomes and safety of doxycycline-moxifloxacin sequential regimen in the treatment of Mycoplasma genitalium urethritis/cervicitis. Methods:From June 2019 to December 2020, patients with Mycoplasma genitalium urethritis/cervicitis confirmed by nucleic acid amplification testing were successively recruited at Department of Sexually Transmitted Diseases, Hospital of Dermatology, Chinese Academy of Medical Sciences, and received sequential therapy with oral doxycycline for 7 days followed by oral moxifloxacin for 7 days. Clinical and/or etiological assessment was conducted 2 to 3 weeks after the end of treatment. Fisher′s exact test was used to analyze factors influencing the treatment outcome. Results:Totally, 36 eligible subjects were enrolled, including 30 males and 6 females. Among them, 18 (50%) patients completed post-treatment etiological assessment, which showed that 12 achieved microbiological cure, and treatment failures occurred in 6; another 18 patients achieved clinical cure. The overall response rate to doxycycline-moxifloacin sequential therapy was 83.3% (30/36, 95% confidence interval[ CI]: 70.5%, 96.1%) . The treatment outcome showed no significant association with the patients′ age, gender, marital status, number of sexual partners in the past 1 month, history of sexually transmitted diseases, history of antibiotic use in the past 1 month, or co-infections (all P > 0.05) . Conclusion:The efficacy of doxycycline-moxifloacin sequential regimen is limited in the treatment of Mycoplasma genitalium infections in Nanjing area, and clinicians should be alerted to the possibility of treatment failure in clinical practice.