Characterization of genital chlamydia trachomatis infection among women attending infertility and gynecology clinics in Hunan, China.

BACKGROUND: Genital infection with Chlamydia trachomatis (C. trachomatis) is a major public health issue worldwide. It can lead to cervicitis, urethritis, and infertility. This study was conducted to determine the characteristics of genital C. trachomatis infection among women attending to the infertility and gynecology clinics. METHODS: Endocervical swabs were collected from 8,221 women for C. trachomatis nucleotide screening and genotyping, while serum samples were collected for C. trachomatis pgp3 antibody determination using luciferase immunosorbent assays. RESULTS: High C. trachomatis DNA prevalence (3.76%) and seroprevalence (47.46%) rates were found, with genotype E (27.5%) being the most prevalent. C. trachomatis omp1 sense mutation was associated with cervical intraepithelial neoplasia (CIN) (odds ratio [OR] = 6.033, 95% confidence interval [CI] = 1.219-39.185, p = 0.045). No significant differences in C. trachomatis seroprevalence rates were observed between women with detectable C. trachomatis DNA in the infertility and routine physical examination groups (86.67% vs. 95%, p > 0.05); however, among women with negative C. trachomatis DNA, the former group had a markedly higher seroprevalence than the latter group (56.74% vs. 20.17%, p < 0.001). C. trachomatis DNA, but not pgp3 antibody, was significantly associated with CIN (OR = 4.087, 95% CI = 2.284-7.315, p < 0.001). CONCLUSION: Our results revealed a high prevalence, particularly seroprevalence, of C. trachomatis among women with infertility. Furthermore, we found an association between C. trachomatis omp1 sense mutations and CIN. Therefore, C. trachomatis serves as a risk factor for CIN.

Identification and characterization of mixed infections of Chlamydia trachomatis via high-throughput sequencing.

Precise genotyping is necessary to understand epidemiology and clinical manifestations of Chlamydia trachomatis infection with different genotypes. Next-generation high-throughput sequencing (NGHTS) has opened new frontiers in microbial genotyping, but has been clinically characterized in only a few settings. This study aimed to determine C. trachomatis genotypes in particular mixed-genotype infections and their association with clinical manifestations and to characterize the sensitivity and accuracy of NGHTS. Cervical specimens were collected from 8,087 subjects from physical examination center (PEC), assisted reproductive technology center (ART) and gynecology clinics (GC) of Chenzhou Hospital of China. The overall prevalence of C. trachomatis was 3.8% (311/8087) whereas a prevalence of 2.8, 3.7 and 4.8% was found in PEC, ART and GC, respectively. The most frequent three C. trachomatis genotypes were E (27.4%, 83/303), F (21.5%, 65/303) and J (18.2%, 55/303). Moreover, NGHTS identified 20 (6.6%, 20/303) mixed-genotype infections of C. trachomatis. Genotype G was more often observed in the subjects with pelvic inflammatory disease than genotype E (adjusted OR = 3.61, 95%CI, 1.02-12.8, p = 0.046). Mixed-genotype infection was associated with severe vaginal cleanliness (degree IV) with an adjusted OR of 5.17 (95%CI 1.03-25.9, p = 0.046) whereas mixed-genotype infection with large proportion of minor genotypes was associated with cervical squamous intraepithelial lesion (SIL) with an adjusted OR of 5.51 (95%CI 1.17-26.01, p = 0.031). Our results indicated that NGHTS is a feasible tool to identity C. trachomatis mixed-genotype infections, which may be associated with worse vaginal cleanliness and cervical SIL.

Lactobacillus Modulates Chlamydia Infectivity and Genital Tract Pathology in vitro and in vivo.

Since we previously reported that women infected with chlamydia had a significant overall reduction in Lactobacillus in the vagina microbiota as compared to those uninfected individuals; the interactions between the altered Lactobacillus and Chlamydia trachomatis, on the other hand, need to be elucidated. Here, we employed both in vitro and in vivo models to evaluate the effects of this changed Lactobacillus on Chlamydia infection. We found that L. iners, L. crispatus, L. jensenii, L. salivarius, L. gasseri, L. mucosae, and L. reuteri all significantly reduced C. trachomatis infection in a dose- and time-dependent manner. The strongest anti-Chlamydia effects were found in L. crispatus (90 percent reduction), whereas the poorest was found in L. iners (50 percent reduction). D (-) lactic acid was the key component in Lactobacillus cell-free supernatants (CFS) to inactivate Chlamydia EBs, showing a positive correlation with the anti-Chlamydia activity. The effects of D (-) lactic acid were substantially attenuated by neutralizing the pH value to 7.0. In vivo, mice intravaginally inoculated with Lactobacillus mixtures (L. crispatus, L. reuteri, and L. iners at a ratio of 1:1:1), but not single Lactobacillus, after genital Chlamydia infection, significantly attenuated the levels of Chlamydia live organism shedding in both the lower genital tract and the intestinal tract, reduced cytokines production (TNF-α, IFN-γ, and IL-1ß) in the vagina, and lessened upper genital tract inflammation and pathogenicity. Taken together, these data demonstrate that Lactobacillus inhibits Chlamydia infectivity both in vivo and in vitro, providing useful information for the development of Lactobacillus as adjunctive treatment in Chlamydia infection.

Fallopian tubal infertility: the result of Chlamydia trachomatis-induced fallopian tubal fibrosis.

Chlamydia trachomatis is one of the most common pathogens of sexually transmitted diseases, and its incidence in genital tract infections is now 4.7% in south China. Infertility is the end result of C. trachomatis-induced fallopian tubal fibrosis and is receiving intense attention from scientists worldwide. To reduce the incidence of infertility, it is important to understand the pathology-related changes of the genital tract where C. trachomatis infection is significant, especially the mechanism of fibrosis formation. During fibrosis development, the fallopian tube becomes sticky and occluded, which will eventually lead to tubal infertility. At present, the mechanism of fallopian tubal fibrosis induced by C. trachomatis infection is unclear. Our study attempted to summarize the possible mechanisms of fibrosis caused by C. trachomatis infection in the fallopian tube by reviewing published studies and further providing potential therapeutic targets to reduce the occurrence of infertility. This study also provides ideas for future research. Factors leading to fallopian tube fibrosis include inflammatory factors, miRNA, ECT, cHSP, and host factors. We hypothesized that C. trachomatis mediates the transcription and translation of EMT and ECM via upregulating TGF signaling pathway, which leads to the formation of fallopian tube fibrosis and ultimately to tubal infertility.

Alterations of Vaginal Microbiota in Women With Infertility and Chlamydia trachomatis Infection.

Chlamydia trachomatis (C. trachomatis) is the most common etiological agent of bacterial sexually transmitted infections (STIs) worldwide and causes serious health sequelae such as cervicitis, pelvic inflammatory disease, and even infertility if ascending from the lower to the upper female genital tract. Previous studies have revealed the pivotal role of vaginal microbiota in susceptibility to STIs. However, alterations in the vaginal microbiota in women who are infertile and infected with C. trachomatis remain unknown. This study used metagenomic analysis of sequenced 16S rRNA gene amplicons to examine the vaginal microbial profiles of women with tubal infertility who were C. trachomatis-negative and those who were C. trachomatis-positive pre- and post-antibiotic treatment. Women who were C. trachomatis-negative and deemed healthy were recruited as references of eubiosis and dysbiosis. Women with tubal infertility and C. trachomatis infection presented a unique Lactobacillus iners-dominated vaginal microbiota rather than one dominated by Lactobacillus crispatus and displayed a decrease in Lactobacillus, Bifidobacterium, Enterobacter, Atopobium, and Streptococcus, accompanied by decreased levels of cytokines such as interferon (IFN)-γ and interleukin (IL)-10. This altered vaginal microbiota could be restored with varying degrees after standard treatment for C. trachomatis. This shift could be a predictive vaginal microbiota signature for C. trachomatis infection among females with tubal infertility, while no significant differences in phylum, class, and operational taxonomic unit (OTU) levels were observed between women with tubal infertility who were C. trachomatis-negative and healthy controls. This is the first study to provide data on the association of vaginal microbiota with C. trachomatis infection among women with tubal infertility and highlights unprecedented potential opportunities to predict C. trachomatis infection.

Prevalence and genotype distribution of HPV infection among 214,715 women from Southern China, 2012-2018: baseline measures prior to mass HPV vaccination.

BACKGROUND: The epidemiology on the human papillomavirus (HPV) among females in Southern China is not well-established. Baseline data on the prevalence of HPV infection in China prior to mass prophylactic HPV vaccination would be useful. Thus, this study aims to determine the type-specific HPV prevalence and distribution among females from Southern China prior to mass HPV vaccination. METHODS: A retrospective cross-sectional study employing 214,715 women attending ChenZhou NO.1 People's Hospital for cervical screening during 2012-2018 was conducted prior to widespread HPV vaccination. HPV genotype was detected using nucleic acid molecular diversion hybridization tests. The overall prevalence, age-specific prevalence, type distribution, and annual trend were analyzed. RESULTS: The overall HPV prevalence was 18.71% (95% confidence interval [CI], 18.55-18.88%) among Southern China females. During 2012-2018, the prevalence of HPV infection showed a downward tendency, from 21.63% (95% CI, 21.07-22.20%) in 2012 to 18.75% (95% CI, 18.35-19.16%) in 2018. Age-specific HPV distribution displayed a peak at young women aged less than 21 years (33.11, 95% CI, 31.13-35.15%), 20.07% (95% CI, 19.70-20.44%) among women aged 21-30 years, 17.29% (95% CI, 17.01-17.57%) among women aged 31-40 years, 17.23% (95% CI, 16.95-17.51%) among women aged 41-50 years, 21.65% (95% CI, 21.11-22.20%) among women aged 51-60 years, and 25.95% (95% CI, 24.86-27.07%) among women aged over 60 years. Of the 21 subtypes identified, the top three prevalent high-risk HPV (HR-HPV) genotypes were HPV52 (5.12%; 95% CI, 21.11-22.20%), - 16 (2.96%; 95% CI, 2.89-3.03%), and - 58 (2.51%; 95% CI, 2.44-2.58%); the predominant low-risk HPV (LR-HPV) genotypes were HPV81 (1.86%; 95%CI, 1.80-1.92%) and - 6 (0.69%; 95% CI, 0.66-0.73%) respectively. Incidence of HR-HPV only, LR-HPV only and mixed LR- and HR-HPV were 15.17, 2.07 and 1.47% respectively. Besides, single HPV infection accounted for 77.30% of all positive cases in this study. CONCLUSIONS: This study highlights 1) a high prevalence of HPV infection among females with a decreasing tendency towards 2012-2018, especially for young women under the age of 21 prior to mass HPV vaccination; 2) HPV52, - 16 and - 58 were the predominant HPV genotypes, suggesting potential use of HPV vaccine covering these HPV genotypes in Southern China.

Chlamydia trachomatis and Human Papillomavirus Infection in Women From Southern Hunan Province in China: A Large Observational Study.

Chlamydia trachomatis and human papillomavirus (HPV) are the most common pathogens of sexually transmitted infections (STIs), which can increase the risk of cervical cancer and infertility. The purpose of this study was to evaluate the prevalence, genotype and risk factors of C. trachomatis and/or HPV infection in women attending the annual physical examination, assistant reproductive treatment and visiting the gynecology clinics from Southern Hunan province in China. Cervical-swab samples were collected from 5006 participants. We found that the overall prevalence of C. trachomatis, HPV infection and C. trachomatis/HPV coinfection was 4.7% (236/5006), 15.5% (778/5006) and 1.2% (59/5006), while the prevalence of asymptomatic infection of that was 3.8% (38/1006), 10.8% (109/1006) and 0.6% (6/1006), respectively. Furthermore, 25.0% (59/236) of C. trachomatis infection and 7.6% (59/778) of HPV infection were attributable to C. trachomatis and HPV coinfection. C. trachomatis and HPV infection were more often observed in young women of less than 25 years (10.4% and 21.3%, respectively) and in the outpatients from gynecology clinics (5.2% and 18.0%, respectively). Of note, a higher prevalence of C. trachomatis infection was observed in HPV-positive women (7.6%) than HPV- negative ones (4.2%), and vice versa. The top three C. trachomatis genotypes were E (1.4%), F (1.1%) and J (0.8%), and the counterparts of HPV genotypes were HPV52 (4.2%), HPV16 (2.3%) and HPV58 (2.2%), respectively. Among the 151 outpatients with colposcopy data, HPV infection was associated with severe cervical lesions with OR of 15.86 (95% CI 3.14-80.0, P < 0.001) while C. trachomatis infection was more likely associated with a low grade colposcopy impression (OR = 3.25, 95% CI: 1.22-8.65, P = 0.018). Our data highlight the high prevalence of asymptomatic C. trachomatis and HPV infection, particularly among women of <25 years. The two pathogens may serve as mutual risk factors to increase the risk of infections and cervical lesions. Widespread implementation of HPV and C. trachomatis screening programs, especially for young women, would be an effective strategy to relieve the burden of sexually transmitted infections.

A ratiometric electrochemical DNA biosensor for detection of exosomal MicroRNA.

The detection of exosomal microRNAs (miRNAs) derived from cancer cells with sensitive and selective methods has stimulated increasing interest due to its potential utility in the application of tumor diagnosis. Here, we developed a ratiometric electrochemical DNA biosensor based on a locked nucleic acid (LNA)-modified "Y" shape-like structure for the detection of exosomal miRNA-21 (miR-21). When miR-21 is present, the LNA-assisted strand displacement reaction on the "Y" shape-like structure is activated, leading to a structure change and augmentation of the signal ratio, which reflects the different distances between the electrode surface and two electroactive molecules labeled on the "Y" shape-like structure. With this dual signal ratiometric method, the biosensor shows high accuracy and sensitivity with a limit of detection as low as 2.3 fM. Moreover, because of the logarithm of the signal ratio displays a linear relationship with the logarithm of the miR-21 concentration, the biosensor is stable enough to be used in the detection of miR-21 in MCF-7 cell-derived exosomes. In addition, the biosensor shows good selectivity even in the detection of even a single base-mismatched target due to the LNA-assisted strand displacement reaction. Notably, the sensor is both regenerative and robust. In brief, the high sensitivity and selectivity, combined with the low cost of the glassy carbon electrode, make this biosensor a promising tool for the development of point-of-care testing in cancer.

Label-free fluorescent and electrochemical biosensors based on defective G-quadruplexes.

Abnormal levels of guanine closely associated with plenty of diseases are usually used as a biomarker for clinical diagnosis. In order to detect guanine and its derivatives accurately, in this paper, a defective G-quadruplex (DGQ) containing a G-vacancy at one of its G-quartet layers, and two kinds of G-quadruplex specific indicators including thioflavine T (ThT) and hemin were used for constructing a fluorescent and an electrochemical biosensor, respectively. In brief, a G-rich DNA probe is designed to form either hairpin or DGQ structure. In the absence of guanine, G-rich probes prefer to maintain hairpin structure and nearly have no interaction with ThT or hemin, leading to almost negligible signals. Upon addition of guanine, the G-rich probe fold into DGQ structure and then the G-vacancy in it is filled up immediately by guanine via Hoogsteen hydrogen bonds, resulting canonical G-quadruplex formation. Accordingly, ThT or hemin can selectively combine with G-quadruplex, giving rise to distinct fluorescent or current signal changes for label-free detection of guanine. Benefiting from the perfect discriminative ability of guanine towards DGQ and ThT/hemin against standard G-quadruplex, the fluorescent and electrochemical biosensors present better sensitivity and selectivity for guanine detection with the limit of detection (LOD) as low as 18.26 and 0.36 nM, respectively. Successful attempts were also made in applying the proposed electrochemical biosensor to detect guanine in drugs and urine, obtaining satisfactory recovery rates of 99~104% and 96~106%, respectively.