Haematopoietic innate interleukin 17A production drives immunopathology in female mouse genital Chlamydia muridarum infection

Chlamydia trachomatis infection is the leading cause of bacterial urogenital infection and has been demonstrated to drive inflammation and scarring of the reproductive tract. Recent studies have identified key triggers of proinflammatory adaptive immune responses driven by innate leukocytes and epithelia driving immunopathology. Utilizing chimeric mouse models, we investigated the definitive source and role of IL17 and IL17 signalling receptors during early Chlamydia muridarum infection of the female urogenital tract. Bone marrow transplants from wild-type (WT) and IL17A-/- mice to recipients demonstrated equivocal infection kinetics in the reproductive tract, but interestingly, adoptive transfer of IL17A-/- immune cells to WT recipients resulted in no infertility, suggesting a haematopoietic (as opposed to tissue) source of IL17 driving immunopathology. To further delineate the role of IL17 in immunopathology, we infected WT and IL17 receptor A (IL17RA)-/- female mice and observed a significant reduction in immunopathology in IL17RA-/- mice. WT bone marrow transplants to IL17RA-/- recipient mice prevented hydrosalpinx, suggesting signalling through IL17RA drives immunopathology. Furthermore, early chemical inhibition of IL17 signalling significantly reduced hydrosalpinx, suggesting IL17 acts as an innate driver of disease. Early during the infection, IL17 was produced by γδ T cells in the cervico-vagina, but more importantly, by neutrophils at the site of infertility in the oviducts. Taken together, these data suggest innate production of IL17 by haematopoietic leukocytes drives immunopathology in the epithelia during early C. muridarum infection of the female reproductive tract.

Antibodies from chlamydia-infected individuals facilitate phagocytosis via Fc receptors

Non-neutralizing functions of antibodies, including phagocytosis, may play a role in Chlamydia trachomatis (CT) infection, but these functions have not been studied and assays are lacking. We utilized a flow-cytometry-based assay to determine whether serum samples from a well-characterized cohort of CT-infected and naïve control individuals enhanced phagocytosis via Fc-receptor-expressing THP-1 cells, and whether this activity correlated with antibody titers. Fc-receptor-mediated phagocytosis was detected only in CT+ donors. Phagocytosis generally did not correlate well with antibody titer. In addition, we found that complement from both CT+ and negative individuals enhanced phagocytosis of CT into primary neutrophils. These results suggest that anti-CT antibodies can have functions that are not reflected by titer. This method could be used to quantitively measure Fc-receptor-mediated function of anti-CT antibodies or complement activity and could reveal new immune correlates of protection.

Chlamydia pneumoniae Upsurge at Tertiary Hospital, Lausanne, Switzerland

Chlamydia pneumoniae infection cases have usually accounted for <1.5% of community-acquired respiratory tract infections. Currently, Lausanne, Switzerland is experiencing a notable upsurge in cases, with 28 reported within a span of a few months. This upsurge in cases highlights the need for heightened awareness among clinicians.

Anti-Idiotypic Nanobodies Mimicking an Epitope of the Needle Protein of the Chlamydial Type III Secretion System for Targeted Immune Stimulation

The development of new approaches and drugs for effective control of the chronic and complicated forms of urogenital chlamydia caused by Chlamydia trachomatis, which is suspected to be one of the main causes of infertility in both women and men, is an urgent task. We used the technology of single-domain antibody (nanobody) generation both for the production of targeting anti-chlamydia molecules and for the subsequent acquisition of anti-idiotypic nanobodies (ai-Nbs) mimicking the structure of a given epitope of the pathogen (the epitope of the Chlamydial Type III Secretion System Needle Protein). In a mouse model, we have shown that the obtained ai-Nbs are able to induce a narrowly specific humoral immune response in the host, leading to the generation of intrinsic anti-Chlamydia antibodies, potentially therapeutic, specifically recognizing a given antigenic epitope of Chlamydia. The immune sera derived from mice immunized with ai-Nbs are able to suppress chlamydial infection in vitro. We hypothesize that the proposed method of the creation and use of ai-Nbs, which mimic and present to the host immune system exactly the desired region of the antigen, create a fundamentally new universal approach to generating molecular structures as a part of specific vaccine for the targeted induction of immune response, especially useful in cases where it is difficult to prepare an antigen preserving the desired epitope in its native conformation.

Contributions of diverse models of the female reproductive tract to the study of Chlamydia trachomatis-host interactions

Chlamydia trachomatis is a common cause of sexually transmitted infections in humans with devastating sequelae. Understanding of disease on all scales, from molecular details to the immunology underlying pathology, is essential for identifying new ways of preventing and treating chlamydia. Infection models of various complexity are essential to understand all aspects of chlamydia pathogenesis. Cell culture systems allow for research into molecular details of infection, including characterization of the unique biphasic Chlamydia developmental cycle and the role of type-III-secreted effectors in modifying the host environment to allow for infection. Multicell type and organoid culture provide means to investigate how cells other than the infected cells contribute to the control of infection. Emerging comprehensive three-dimensional biomimetic systems may fill an important gap in current models to provide information on complex phenotypes that cannot be modeled in simpler in vitro models.

Insights into innate immune cell evasion by Chlamydia trachomatis

Chlamydia trachomatis, is a kind of obligate intracellular pathogen. The removal of C. trachomatis relies primarily on specific cellular immunity. It is currently considered that CD4+ Th1 cytokine responses are the major protective immunity against C. trachomatis infection and reinfection rather than CD8+ T cells. The non-specific immunity (innate immunity) also plays an important role in the infection process. To survive inside the cells, the first process that C. trachomatis faces is the innate immune response. As the "sentry" of the body, mast cells attempt to engulf and remove C. trachomatis. Dendritic cells present antigen of C. trachomatis to the "commanders" (T cells) through MHC-I and MHC-II. IFN-γ produced by activated T cells and natural killer cells (NK) further activates macrophages. They form the body's "combat troops" and produce immunity against C. trachomatis in the tissues and blood. In addition, the role of eosinophils, basophils, innate lymphoid cells (ILCs), natural killer T (NKT) cells, γδT cells and B-1 cells should not be underestimated in the infection of C. trachomatis. The protective role of innate immunity is insufficient, and sexually transmitted diseases (STDs) caused by C. trachomatis infections tend to be insidious and recalcitrant. As a consequence, C. trachomatis has developed a unique evasion mechanism that triggers inflammatory immunopathology and acts as a bridge to protective to pathological adaptive immunity. This review focuses on the recent advances in how C. trachomatis evades various innate immune cells, which contributes to vaccine development and our understanding of the pathophysiologic consequences of C. trachomatis infection.

Requirement of GrgA for Chlamydia infectious progeny production, optimal growth, and efficient plasmid maintenance

IMPORTANCE

Hallmarks of the developmental cycle of the obligate intracellular pathogenic bacterium Chlamydia are the primary differentiation of the infectious elementary body (EB) into the proliferative reticulate body (RB) and the secondary differentiation of RBs back into EBs. The mechanisms regulating these transitions remain unclear. In this report, we developed an effective novel strategy termed dependence on plasmid-mediated expression (DOPE) that allows for the knockdown of essential genes in Chlamydia. We demonstrate that GrgA, a Chlamydia-specific transcription factor, is essential for the secondary differentiation and optimal growth of RBs. We also show that GrgA, a chromosome-encoded regulatory protein, controls the maintenance of the chlamydial virulence plasmid. Transcriptomic analysis further indicates that GrgA functions as a critical regulator of all three sigma factors that recognize different promoter sets at developmental stages. The DOPE strategy outlined here should provide a valuable tool for future studies examining chlamydial growth, development, and pathogenicity.

A structural foundation for studying chlamydial polymorphic membrane proteins

IMPORTANCE

Infections by bacteria in the genus Chlamydia cause a range of widespread and potentially debilitating conditions in humans and other animals. We analyzed predicted structures of a family of proteins that are potential vaccine targets found in all Chlamydia spp. Our findings deepen the understanding of protein structure, provide a descriptive framework for discussion of the protein structure, and outline regions of the proteins that may be key targets in host-microbe interactions and anti-chlamydial immunity.

Progesterone-mediated immunoregulation of cytokine signaling by miRNA-133a and 101-3p in Chlamydia trachomatis-associated recurrent spontaneous abortion

miRNAs regulate the expression of various genes involved in cellular and metabolic pathways in pregnancy related complications including recurrent spontaneous abortion (RSA). Modulation of progesterone and associated pro-inflammatory cytokines by miRNAs in Chlamydia trachomatis-associated RSA is still under investigation. Present study aimed to evaluate the expression/correlation of serum-circulating miRNAs-133a, 101-3p, 320b, 146b-5p, 24, 559, progesterone and few cytokines in C. trachomatis-positive spontaneous aborters. Non-heparinized blood and urine was collected from 120 patients with history of RSA (Group I) and 120 patients with ≥ 2 successful deliveries (Group II) attending Department of Obstetrics and Gynecology, Safdarjung hospital, New Delhi, India. C. trachomatis detection was performed by PCR and chlamydial load by real time PCR. Progesterone concentration was estimated by ELISA. miRNAs and cytokine expression was studied by quantitative real-time PCR and correlated with progesterone expression. Twenty six patients were found to be positive for C. trachomatis. miRNAs- 133a, 101-3p showed maximum upregulation in infected versus control patients. miRNA expression showed positive correlation with chlamydial load. Progesterone concentration showed significant decrease while cytokines (IL-6, IFN-γ, TNF-α) were significantly upregulated in C. trachomatis-positive patients. Positive correlation was observed between expression of miRNAs-133a and 101-3p and cytokines while negative correlation was observed with progesterone in infected RSA patients. Correlation between progesterone and cytokines was found to be significantly negative in infected RSA patients. Although further validation is required, the study concludes that miR-133a and 101-3p are of clinical importance and have a role in immunoregulation of progesterone and cytokines in infection associated RSA.

Interferon-ε as potential inhibitor of Chlamydia trachomatis infection

Chlamydia trachomatis, the main cause of bacterial sexually transmitted diseases, is responsible for severe reproductive sequelae. Amongst all the cytokines involved in host immunity towards this pathogen, IFN-ε has recently acquired importance for its potential contribution to the female reproductive tract innate defenses. Herein, our study aimed to explore, for the first time, the activity of IFN-ε toward C. trachomatis in an in vitro infection model, by testing its effects on the different phases of chlamydial developmental cycle, as well as on the ultrastructural characteristics of chlamydial inclusions, via transmission electron microscopy. Main result is the capability of IFN-ε to alter C. trachomatis growth, as suggested by reduced infectious progenies, as well as a patchy distribution of bacteria and altered morphology of reticulate bodies within inclusions. In conclusion, our results suggest that IFN-ε could play a role in the innate and adaptive immune defenses against C. trachomatis; in the future, it will be needed to investigate its activity on an infection model more closely resembling the physiological environment of the female genital tract.

Lack of neutralization of Chlamydia trachomatis infection by high avidity monoclonal antibodies to surface-exposed major outer membrane protein variable domain IV

Chlamydia trachomatis is the leading cause of sexually transmitted diseases causing frequent, long-lasting, and often asymptomatic recurrent infections resulting in severe reproductive complications. C. trachomatis is an intracellular Gram-negative bacterium with a biphasic developmental cycle in which extracellular, infectious elementary bodies (EB) alternate with the intracellular replicating reticulate bodies (RB). The outer membrane of EB consists of a tight disulfide cross-linking protein network. The most essential protein is the 42 kDa major outer membrane protein (MOMP) that contributes to the rigid structural integrity of the outer membrane. MOMP is a transmembrane protein with a β-barrel structure consisting of four variable domains (VD) separated by five constant domains. VDIV possesses surface-exposed species-specific epitopes recognized by the immune system and, therefore, functions as a candidate for vaccine development. To analyze the protective contribution of antibodies for a MOMP vaccine, we investigated the specificity and binding characteristics of two monoclonal antibodies (MAb)224.2 and MAb244.4 directed against C. trachomatis serovar D MOMP. By immunoelectron microscopy, we found that both MAb bind to the surface of C. trachomatis EB. By epitope mapping, we characterized the MOMP epitope as linear consisting of 6 amino acids: 322TIAGAGD328. By ELISA it was shown that both antibodies bind with a higher avidity to the chlamydial surface compared to binding to monomeric MOMP, indicating that the antibodies bind divalently to the surface of C. trachomatis EB. Despite strong binding to the chlamydial surface, the antibodies only partially reduced the infectivity. This may be explained by the observation that even though both MAb covered the EB surface, antibodies could not be regularly detected on EB after the uptake into the host cell.

Diabetic MAFLD is associated with increased risk of hepatocellular carcinoma and mortality in chronic viral hepatitis patients

Metabolic dysfunction-associated fatty liver disease (MAFLD) can coexist with chronic viral hepatitis. MAFLD is a heterogeneous disease because the diagnostic criteria include various metabolic traits. We aimed to identify patients at high risk of poor long-term outcomes based on MAFLD subgroups in chronic viral hepatitis patients. We evaluated 63 273 chronic hepatitis B and C patients. Patient with a fatty liver index ≥30 was defined to have hepatic steatosis. MAFLD was defined as the presence of hepatic steatosis with any one of the following three conditions, overweight/obesity, type 2 diabetes or ≥2 metabolic risk factors. The prevalence of MAFLD was 38.4% (n = 24 290). During a median 8.8-year follow-up, 1839 HCCs and 2258 deaths were documented in MAFLD patients. Among MAFLD patients, diabetes could identify patients at high risk of HCC and mortality, whereas overweight/obesity and metabolic risk factors did not. Compared with non-MAFLD patients, risk of HCC and mortality was significantly higher in diabetic MAFLD patients (adjusted hazard ratio [aHR] = 1.34, 95% confidence interval [CI] = 1.26-1.43 for HCC; aHR = 1.15, 95% CI = 1.08-1.22 for mortality). Risk of HCC and mortality was significantly higher in diabetic MAFLD patients (aHR = 1.40, 95% CI = 1.26-1.55 for HCC; aHR = 1.77, 95% CI = 1.63-1.93 for mortality) compared with non-diabetic MAFLD patients. Diabetic MAFLD is associated with increased risk of HCC and mortality among chronic viral hepatitis patients. Our findings highlight the need for close surveillance and effective treatment for these high-risk patients to reduce HCC and mortality in patients with chronic viral hepatitis.

Apulian infectious diseases network: survey on the prevalence of delta infection among chronic HBV carriers in Apulia

Background

The current prevalence and clinical burden of Hepatitis Delta Virus (HDV) infection in Apulia are unknown. This study aimed to define the current epidemiological scenario of delta infection and to detect difficulties in the diagnosis and clinical management of HDV patients in Apulia.

Methods

From May to September 2022, a fact-finding survey was conducted at eight Infectious Diseases Units of the Apulian region; each Unit was asked to complete a questionnaire on screening and diagnosis of HDV infection and demographic, virological, and clinical characteristics of HDV patients.

Results

A total of 1,461 HBsAg-positive subjects were followed up on an outpatient basis. Screening for HDV ranged from 30 to 90% of HBsAg + carriers in a single center. Overall, 952 HBsAg ± subjects (65%) were tested for HDV, and 80/952 (8.4%) were anti-HDV positive. Serum HDV RNA was detected only in 15/80 (19%) anti-HDV-positive subjects, and 12/15 patients (80%) were viremic. Sixty-five anti-HDV-positive subjects (81%) were from Italy; risk factors for HDV acquisition included the presence of HDV infection in the family (29/80 = 36%), drug addiction (12/80 = 15%), and co-infection with HCV or HIV (7/80 = 9%). Liver cirrhosis and hepatocellular carcinoma were diagnosed in 41 (51%) and 4 (5%) patients, respectively. Fifty-seven patients (71%) received nucleos(t)ide analog treatment.

Conclusions

The results of this survey show that HDV screening is variable and insufficient, thus real prevalence data on delta infection are lacking in Apulia. Moreover, the HDV RNA test is not available in most laboratories and is not provided by the national health system. These results underline the need for an organizational model to optimize the management of HDV patients throughout the Apulian region.

Trends of hospitalisation for patients with liver cirrhosis in Ningxia, China: a cross-sectional study

OBJECTIVE

To evaluate the changing trends of hospitalisation for patients with liver cirrhosis between 2015 and 2019 by using hospitalisation summary records in Ningxia Hui Autonomous Region (NHAR), China.

DESIGN

A cross-sectional study.

SETTING

Hospitalisation summary records between 1 January 2015 and 31 December 2019 from 28 top-ranking hospitals in NHAR were extracted and rigorously analysed.

PARTICIPANTS

During the study period, hospitalisation records referring to liver cirrhosis were included. Records with missing data were excluded. A total of 16 566 patients with liver cirrhosis were included in this study.

OUTCOME MEASURES

International Classification of Diseases codes, tenth version (ICD-10) and text-diagnoses were used to identify hospitalisation records referring to liver cirrhosis.

RESULTS

Between 2015 and 2019, hospitalisation rates for liver cirrhosis declined from 8.38% to 5.57%. Chronic viral hepatitis accounted for almost 70% of all liver cirrhosis admissions; the remaining 30% of patients were admitted due to non-viral hepatitis cirrhosis (28.06%) and alcoholic cirrhosis (2.05%). The male-to-female hospitalisation rate ratio for liver cirrhosis was 2.57. The hospitalisation rate for workers with hepatitis cirrhosis was significantly higher than farmers (hospitalisation rate ratio (RR)=1.06, 95% CI 1.01 to 1.15, p<0.001); this was also the case for alcoholic cirrhosis (RR=5.23, 95% CI 3.34 to 8.20). However, the hospitalisation rate for workers with non-viral hepatitis cirrhosis was significantly lower than for farmers (RR=5.23, 95% CI 3.34 to 8.20, p<0.001). The hospitalisation rate increased in patients over the age of 30 years and reached a peak at the age of 45-50 years.

CONCLUSIONS

The hospitalisation rate for liver cirrhosis has declined over recent years and chronic viral hepatitis remains the major cause of liver cirrhosis in NHAR. Hospitalisation summary records can efficiently reflect the local changing trends of hospitalisation for liver cirrhosis and represent an efficient strategy for the surveillance of chronic disease.

A Machine Learning-Based Analytic Pipeline Applied to Clinical and Serum IgG Immunoproteome Data To Predict Chlamydia trachomatis Genital Tract Ascension and Incident Infection in Women

We developed a reusable and open-source machine learning (ML) pipeline that can provide an analytical framework for rigorous biomarker discovery. We implemented the ML pipeline to determine the predictive potential of clinical and immunoproteome antibody data for outcomes associated with Chlamydia trachomatis (Ct) infection collected from 222 cis-gender females with high Ct exposure. We compared the predictive performance of 4 ML algorithms (naive Bayes, random forest, extreme gradient boosting with linear booster [xgbLinear], and k-nearest neighbors [KNN]), screened from 215 ML methods, in combination with two different feature selection strategies, Boruta and recursive feature elimination. Recursive feature elimination performed better than Boruta in this study. In prediction of Ct ascending infection, naive Bayes yielded a slightly higher median value of are under the receiver operating characteristic curve (AUROC) 0.57 (95% confidence interval [CI], 0.54 to 0.59) than other methods and provided biological interpretability. For prediction of incident infection among women uninfected at enrollment, KNN performed slightly better than other algorithms, with a median AUROC of 0.61 (95% CI, 0.49 to 0.70). In contrast, xgbLinear and random forest had higher predictive performances, with median AUROC of 0.63 (95% CI, 0.58 to 0.67) and 0.62 (95% CI, 0.58 to 0.64), respectively, for women infected at enrollment. Our findings suggest that clinical factors and serum anti-Ct protein IgGs are inadequate biomarkers for ascension or incident Ct infection. Nevertheless, our analysis highlights the utility of a pipeline that searches for biomarkers and evaluates prediction performance and interpretability. IMPORTANCE Biomarker discovery to aid early diagnosis and treatment using machine learning (ML) approaches is a rapidly developing area in host-microbe studies. However, lack of reproducibility and interpretability of ML-driven biomarker analysis hinders selection of robust biomarkers that can be applied in clinical practice. We thus developed a rigorous ML analytical framework and provide recommendations for enhancing reproducibility of biomarkers. We emphasize the importance of robustness in selection of ML methods, evaluation of performance, and interpretability of biomarkers. Our ML pipeline is reusable and open-source and can be used not only to identify host-pathogen interaction biomarkers but also in microbiome studies and ecological and environmental microbiology research.

Plasmid-mediated virulence in Chlamydia

Chlamydia trachomatis infection of ocular conjunctiva can lead to blindness, while infection of the female genital tract can lead to chronic pelvic pain, ectopic pregnancy, and/or infertility. Conjunctival and fallopian tube inflammation and the resulting disease sequelae are attributed to immune responses induced by chlamydial infection at these mucosal sites. The conserved chlamydial plasmid has been implicated in enhancing infection, via improved host cell entry and exit, and accelerating innate inflammatory responses that lead to tissue damage. The chlamydial plasmid encodes eight open reading frames, three of which have been associated with virulence: a secreted protein, Pgp3, and putative transcriptional regulators, Pgp4 and Pgp5. Although Pgp3 is an important plasmid-encoded virulence factor, recent studies suggest that chlamydial plasmid-mediated virulence extends beyond the expression of Pgp3. In this review, we discuss studies of genital, ocular, and gastrointestinal infection with C. trachomatis or C. muridarum that shed light on the role of the plasmid in disease development, and the potential for tissue and species-specific differences in plasmid-mediated pathogenesis. We also review evidence that plasmid-associated inflammation can be independent of bacterial burden. The functions of each of the plasmid-encoded proteins and potential molecular mechanisms for their role(s) in chlamydial virulence are discussed. Although the understanding of plasmid-associated virulence has expanded within the last decade, many questions related to how and to what extent the plasmid influences chlamydial infectivity and inflammation remain unknown, particularly with respect to human infections. Elucidating the answers to these questions could improve our understanding of how chlamydia augment infection and inflammation to cause disease.

Nitric Oxide-Producing Polymorphonuclear Neutrophils Confer Protection Against Chlamydia psittaci in Mouse Lung Infection

BACKGROUND

Whether polymorphonuclear neutrophils (PMN) exert a protective role upon chlamydial infection by expressing inducible nitric oxide (NO) synthase (iNOS) and producing NO remains unclear.

METHODS

This issue was addressed using BALB/c mice infected with Chlamydia psittaci 6BC strain. Methods included flow cytometry, immunofluorescence, qRT-PCR, and western blot.

RESULTS

The number of PMN was significantly increased during C. psittaci infection, which was accompanied by increased iNOS expression and NO production in the mouse lungs. PMN were the major source of NO during pulmonary C. psittaci infection and inhibited C. psittaci multiplication in an iNOS/NO-dependent manner. Depletion of PMN aggravated C. psittaci-induced disease and increased C. psittaci burden. Nuclear factor-κB (NF-κB) and STAT1 signaling pathways, but not MAPK signaling pathways, were required for the induction of iNOS expression and NO production in PMN by C. psittaci infection. Thus, our findings highlight the protective role of NO-producing PMN in C. psittaci infection.

CONCLUSIONS

NO-producing PMN confer a protective role during pulmonary C. psittaci infection in mice, and thus our study sheds new light on PMN function during Chlamydia infection.

IL-21/IL-21R Promotes the Pro-Inflammatory Effects of Macrophages during C. muridarum Respiratory Infection

Interleukin-21 and its receptors (IL-21/IL-21R) aggravate chlamydial lung infection, while macrophages (Mφ) are one of the main cells infected by chlamydia and the main source of inflammatory cytokines. Therefore, it is particularly important to study whether IL-21/IL-21R aggravates chlamydia respiratory infection by regulating Mφ. Combined with bioinformatics analysis, we established an IL-21R-deficient (IL-21R-/-) mouse model of Chlamydia muridarum (C. muridarum) respiratory tract infection in vivo, studied C. muridarum-stimulated RAW264.7 by the addition of rmIL-21 in vitro, and conducted adoptive transfer experiments to clarify the association between IL-21/IL-21R and Mφ. IL-21R-/- mice showed lower infiltration of pulmonary total Mφ, alveolar macrophages, and interstitial macrophages compared with WT mice following infection. Transcriptomic analysis suggested that M1-related genes are downregulated in IL-21R-/- mice and that IL-21R deficiency affects the Mφ-mediated inflammatory response during C. muridarum infection. In vivo experiments verified that in IL-21R-/- mice, pulmonary M1-type CD80+, CD86+, MHC II+, TNFα+, and iNOS+ Mφ decreased, while there were no differences in M2-type CD206+, TGF-β+, IL-10+ and ARG1+ Mφ. In vitro, administration of rmIL-21 to C. muridarum-stimulated RAW264.7 cells promoted the levels of iNOS-NO and the expression of IL-12p40 and TNFα, but had no effect on TGFβ or IL-10. Further, adoptive transfer of M1-like bone marrow-derived macrophages derived from IL-21R-/- mice, unlike those from WT mice, effectively protected the recipients against C. muridarum infection and induced relieved pulmonary pathology. These findings help in understanding the mechanism by which IL-21/IL-21R exacerbates chlamydia respiratory infection by promoting the proinflammatory effect of Mφ.

Functional interferon-epsilon gene polymorphisms and sexually transmitted infections of the endometrium

PROBLEM

Interferon-epsilon (IFNε) is the only type I IFN constitutively expressed in the female reproductive tract and fluctuates across the menstrual cycle in humans. Mouse models show that IFNε protects against Chlamydia trachomatis, Herpes Simplex Virus, HIV, and Zika in mice, but human studies are limited. Bacterial sexually transmitted infections (STI) can ascend to the upper genital tract and cause pelvic inflammatory disease (PID) and subsequent infertility. However, the host immunological mechanisms that play a role in the ascension and infection of the endometrium in individuals with clinically suspected PID are not elucidated.

METHOD OF STUDY

This pilot investigation determined if IFNε gene variants are associated with bacterial vaginosis (BV) and endometrial infection with C. trachomatis, Neisseria gonorrhoeae, and Mycoplasma genitalium using biospecimens from 154 self-report Black individuals who participated in the PID Evaluation and Clinical Health (PEACH) study.

RESULTS

The T allele for rs2039381 was associated with endometrial STI infection (OR 2.7, 95% CI: 1.0-7.1) and the C allele for rs1125488 was inversely associated with BV (OR: .2, 95% CI: .05-.8).

CONCLUSIONS

Few studies have examined IFNε gene variants, our study raises the possibility that IFNε gene variants may be a potential host contributor to STI pathogenesis.

Identification and Preliminary Characterization of Novel Type III Secreted Effector Proteins in Chlamydia trachomatis

Chlamydia trachomatis is an obligate intracellular pathogen that replicates in a host-derived vacuole termed the inclusion. Central to pathogenesis is a type III secretion system that translocates effector proteins into the host cell, which are predicted to play major roles in host cell invasion, nutrient acquisition, and immune evasion. However, until recently, the genetic intractability of C. trachomatis hindered identification and characterization of these important virulence factors. Here, we sought to expand the repertoire of identified effector proteins and confirm they are secreted during C. trachomatis infection. Utilizing bioinformatics, we identified 18 candidate substrates that had not been previously assessed for secretion, of which we show four to be secreted, using Yersinia pseudotuberculosis as a surrogate host. Using adenylate cyclase (CyaA), BlaM, and glycogen synthase kinase (GSK) secretion assays, we identified nine novel substrates that were secreted in at least one assay. Interestingly, only three of the substrates, shown to be translocated by C. trachomatis, were similarly secreted by Y. pseudotuberculosis. Using large-scale screens to determine subcellular localization and identify effectors that perturb crucial host cell processes, we identified one novel substrate, CT392, that is toxic when heterologously expressed in Saccharomyces cerevisiae. Toxicity required both the N- and C-terminal regions of the protein. Additionally, we show that these newly described substrates traffic to distinct host cell compartments, including vesicles and the cytoplasm. Collectively, our study expands the known repertoire of C. trachomatis secreted factors and highlights the importance of testing for secretion in the native host using multiple secretion assays when possible.

Sexually Transmitted Infection/Human Immunodeficiency Virus, Pregnancy, and Mental Health-Related Services Provided During Visits With Sexual Assault and Abuse Diagnosis for US Medicaid Beneficiaries, 2019

BACKGROUND

Centers for Disease Control recommends that the decision to provide sexually transmitted infection (STI)/human immunodeficiency virus (HIV) testing and presumptive treatment to patients who report sexual assault and abuse (SAA) be made on an individual basis.

METHODS

The 2019 Centers for Medicare & Medicaid Services national Medicaid data set was used. The SAA visits were identified by International Classification of Diseases 10th Revision Clinical Modification (O9A4 for pregnancy-related sexual abuse, T74.2 for confirmed sexual abuse, and Z04.4 for alleged rape). The initial SAA visit was defined as the patient's first SAA-related visit. Medical services were identified by International Classification of Diseases 10th Revision Clinical Modification codes, Current Procedural Terminology codes, and National Drug Code codes.

RESULTS

Of 55,113 patients at their initial SAA visits, 86.2% were female; 63.4% aged ≥13 years; 59.2% visited emergency department (ED); all STI/HIV tests were provided in ≤20% of visits; presumptive gonorrhea and chlamydia treatment was provided in 9.7% and 3.4% of visits, respectively; pregnancy test was provided in 15.7% of visits and contraception services was provided in 9.4% of visits; and diagnosed anxiety was provided in 6.4% of visits. Patients who visited ED were less likely to have STI testing and anxiety than those visited non-ED facilities, but more likely to receive presumptive treatment for gonorrhea, testing for pregnancy, and contraceptive services. About 14.2% of patients had follow-up SAA visits within 60 days after the initial SAA visit. Of 7821 patients with the follow-up SAA visits within 60 days, most medical services provided were chlamydia testing (13.8%), gonorrhea testing (13.5%), syphilis testing (12.8%), HIV testing (14.0%); diagnosed anxiety (15.0%), and posttraumatic stress disorder (9.8%).

CONCLUSIONS

Current medical services during SAA visits for Medicaid patients are described in this evaluation. More collaboration with staff who handle SAA will improve SAA-related medical services.

Type-I Interferon Signaling Protects against Chlamydia trachomatis Infection in the Female Lower Genital Tract

We have previously shown that Chlamydia trachomatis is significantly inhibited during the early stage of infection in the female mouse lower genital tract and the anti-C. trachomatis innate immunity is compromised in the absence of cGAS-STING signaling. Since type-I interferon is a major downstream response of the cGAS-STING signaling, we evaluated the effect of type-I interferon signaling on C. trachomatis infection in the female genital tract in the current study. The infectious yields of chlamydial organisms recovered from vaginal swabs along the infection course were carefully compared between mice with or without deficiency in type-I interferon receptor (IFNαR1) following intravaginal inoculation with 3 different doses of C. trachomatis. It was found that IFNαR1-deficient mice significantly increased the yields of live chlamydial organisms on days 3 and 5, providing the 1st experimental evidence for a protective role of type-I interferon signaling in preventing C. trachomatis infection in mouse female genital tract. Further comparison of live C. trachomatis recovered from different genital tract tissues between wild type and IFNαR1-deficient mice revealed that the type-I interferon-dependent anti-C. trachomatis immunity was restricted to mouse lower genital tract. This conclusion was validated when C. trachomatis was inoculated transcervically. Thus, we have demonstrated an essential role of type-I interferon signaling in innate immunity against C. trachomatis infection in the mouse lower genital tract, providing a platform for further revealing the molecular and cellular basis of type-I interferon-mediated immunity against sexually transmitted infection with C. trachomatis.

Decomposition of variation of mixed variables by a latent mixed Gaussian copula model

Many biomedical studies collect data of mixed types of variables from multiple groups of subjects. Some of these studies aim to find the group-specific and the common variation among all these variables. Even though similar problems have been studied by some previous works, their methods mainly rely on the Pearson correlation, which cannot handle mixed data. To address this issue, we propose a latent mixed Gaussian copula (LMGC) model that can quantify the correlations among binary, ordinal, continuous, and truncated variables in a unified framework. We also provide a tool to decompose the variation into the group-specific and the common variation over multiple groups via solving a regularized M-estimation problem. We conduct extensive simulation studies to show the advantage of our proposed method over the Pearson correlation-based methods. We also demonstrate that by jointly solving the M-estimation problem over multiple groups, our method is better than decomposing the variation group by group. We also apply our method to a Chlamydia trachomatis genital tract infection study to demonstrate how it can be used to discover informative biomarkers that differentiate patients.

The Periplasmic Tail-Specific Protease, Tsp, Is Essential for Secondary Differentiation in Chlamydia trachomatis

The obligate intracellular human pathogen Chlamydia trachomatis (Ctr) undergoes a complex developmental cycle in which the bacterium differentiates between two functionally and morphologically distinct forms: the elementary body (EB) and the reticulate body (RB). The EB is the smaller, infectious, nondividing form which initiates infection of a susceptible host cell, whereas the RB is the larger, non-infectious form which replicates within a membrane-bound vesicle called an inclusion. The mechanism(s) which drives differentiation between these developmental forms is poorly understood. Bulk protein turnover is likely required for chlamydial differentiation given the significant differences in the protein repertoires and functions of the EB and RB. We hypothesize that periplasmic protein turnover is also critical for the reorganization of an RB into an EB, referred to as secondary differentiation. Ct441 is a periplasmic protease ortholog of tail-specific proteases (i.e., Tsp, Prc) and is expressed in Ctr during secondary differentiation. We investigated the effect of altering Tsp expression on developmental cycle progression. Through assessment of bacterial morphology and infectious progeny production, we found that both overexpression and CRISPR interference/dCas9 (CRISPRi)-mediated knockdown of Tsp negatively impacted chlamydial development through different mechanisms. We also confirmed that catalytic activity is required for the negative effect of overexpression and confirmed the effect of the mutation in in vitro assays. Electron microscopic assessments during knockdown experiments revealed a defect in EB morphology, directly linking Tsp function to secondary differentiation. These data implicate Ct441/Tsp as a critical factor in secondary differentiation. IMPORTANCE The human pathogen Chlamydia trachomatis is the leading cause of preventable infectious blindness and bacterial sexually transmitted infections worldwide. This pathogen has a unique developmental cycle that alternates between distinct forms. However, the key processes of chlamydial development remain obscure. Uncovering the mechanisms of differentiation between its metabolically and functionally distinct developmental forms may foster the discovery of novel Chlamydia-specific therapeutics and limit development of resistant bacterial populations derived from the clinical use of broad-spectrum antibiotics. In this study, we investigate chlamydial tail-specific protease (Tsp) and its function in chlamydial growth and development. Our work implicates Tsp as essential to chlamydial developmental cycle progression and indicates that Tsp is a potential drug target for Chlamydia infections.

Induction of Transmucosal Protection by Oral Vaccination with an Attenuated Chlamydia

Chlamydia muridarum has been used to study chlamydial pathogenesis because it induces mice to develop hydrosalpinx, a pathology observed in C. trachomatis-infected women. We identified a C. muridarum mutant that is no longer able to induce hydrosalpinx. In the current study, we evaluated the mutant as an attenuated vaccine. Following an intravaginal immunization with the mutant, mice were protected from hydrosalpinx induced by wild-type C. muridarum. However, the mutant itself productively colonized the mouse genital tract and produced infectious organisms in vaginal swabs. Nevertheless, the mutant failed to produce infectious shedding in the rectal swabs following an oral inoculation. Importantly, mice orally inoculated with the mutant mounted transmucosal immunity against challenge infection of wild-type C. muridarum in the genital tract. The protection was detected as early as day 3 following the genital challenge infection and the orally immunized mice were protected from any significant pathology in the upper genital tract. However, the same orally immunized mice failed to prevent the colonization of wild-type C. muridarum in the gastrointestinal tract. The transmucosal immunity induced by the oral mutant was further validated in the airway. The orally vaccinated mice were protected from both lung infection and systemic toxicity caused by intranasally inoculated wild-type C. muridarum although the same mice still permitted the gastrointestinal colonization by the wild-type C. muridarum. These observations suggest that the mutant C. muridarum may be developed into an intracellular oral vaccine vector (or IntrOv) for selectively inducing transmucosal immunity in extra-gut tissues.

Preparation of graphene oxide-stabilized Pickering emulsion adjuvant for Pgp3 recombinant vaccine and enhanced immunoprotection against Chlamydia Trachomatis infection

Background

Traditional emulsion adjuvants are limited in clinical application because of their surfactant dependence. Graphene oxide (GO) has unique amphiphilic properties and therefore has potential to be used as a surfactant substitute to stabilize Pickering emulsions.

Methods

In this study, GO-stabilized Pickering emulsion (GPE) was prepared and used as an adjuvant to facilitate an enhanced immune response to the Chlamydia trachomatis (Ct) Pgp3 recombinant vaccine. Firstly, GPE was prepared by optimizing the sonication conditions, pH, salinity, GO concentration, and water/oil ratio. GPE with small-size droplets was characterized and chosen as the candidate. Subsequently, controlled-release antigen delivery by GPE was explored. Cellular uptake behaviors, M1 polarization, and cytokine stimulation by GPE + Pgp3 was considered in terms of the production of macrophages. Finally, GPE's adjuvant effect was evaluated by vaccination with Pgp3 recombinant in BALB/c mouse models.

Results

GPE with the smallest droplet sizes was prepared by sonication under 163 W for 2 min at 1 mg/mL GO in natural salinity with a pH of 2 when the water/oil ratio was 10:1 (w/w). The optimized average GPE droplet size was 1.8 μm and the zeta potential was -25.0 ± 1.3 mv. GPE delivered antigens by adsorption onto the droplet surface, demonstrating the controlled release of antigens both in vitro and in vivo. In addition, GPE promoted antigen uptake, which stimulated proinflammatory tumor necrosis factor alpha (TNF-α), enhancing the M1 polarization of macrophages in vitro. Macrophage recruitment was also significantly promoted by GPE at the injection site. In the GPE + Pgp3 treatment group, higher levels of immunoglobin (IgG), immunoglobin G1 (IgG1), immunoglobin G2a (IgG2a) sera, and immunoglobin A (IgA) were detected in vaginal fluid, and higher levels of IFN-γ and IL-2 secretion were stimulated, than in the Pgp3 group, showing a significant type 1 T helper (Th1)-type cellular immune response. Chlamydia muridarum challenging showed that GPE enhanced Pgp3's immunoprotection through its advanced clearance of bacterial burden and alleviation of chronic pathological damage in the genital tract.

Conclusion

This study enabled the rational design of small-size GPE, shedding light on antigen adsorption and control release, macrophage uptake, polarization and recruitment, which enhanced augmented humoral and cellular immunity and ameliorated chlamydial-induced tissue damage in the genital tract.

Sexually Transmitted Diseases among Saudi Women: Knowledge and Misconceptions

The rate of sexually transmitted diseases is increasing globally. Thus, this study aimed to examine the Al akami female community's knowledge about the nature of sexually transmitted diseases and their associated factors. The STDs-Knowledge Questionnaire (STDs-KQ) was utilized to collect data from the female community (355) in Jeddah, Saudi Arabia. The data were analyzed using JMP Statistics for Windows, version 15. The significance level was set at 0.05. The study reported that participants had a relatively low understanding of STDs in acquisition, protection, prevention, and clinical signs and symptoms; only 33 (9%) had high knowledge scores (10-18), while 70% thought one virus caused all forms of STDs. Also, only 15% of the respondents knew the clinical features of the Chlamydia infection, and 18% identified the correct mode of its transmission. Also, older participants with clinical exposure had a higher knowledge score than young and single females, p < 0.05. A positive correlation between age and knowledge score was reported, r (354) = 0.339, p < 0.0001. The low knowledge scores were associated with marital status, age, and clinical exposure. Practical strategies to minimize literacy toward sexual education and increase the quality of sexual life must be promoted by educators and the academic curriculum.

Regulation of chlamydial colonization by IFNγ delivered via distinct cells

The mouse-adapted pathogen Chlamydia muridarum (CM) induces pathology in the mouse genital tract but fails to do so in the gastrointestinal tract. CM is cleared from both the genital tract and small intestine by IFNγ delivered by antigen-specific CD4+ T cells but persists for a long period in the large intestine. The long-lasting colonization of CM in the large intestine is regulated by IFNγ delivered by group 3 innate lymphoid cells (ILC3s). Interestingly, the ILC3-delivered IFNγ can inhibit the human pathogen Chlamydia trachomatis (CT) in the mouse endometrium. Thus, IFNγ produced/delivered by different cells may selectively restrict chlamydial colonization in different tissues. Revealing the underlying mechanisms of chlamydial interactions with IFNγ produced by different cells may yield new insights into both chlamydial pathogenicity and mucosal immunity.

New insights into Chlamydia pathogenesis: Role of leukemia inhibitory factor

Chlamydia trachomatis (Ct) is the leading cause of bacterial sexually transmitted infections worldwide. Since the symptoms of Ct infection are often subtle or absent, most people are unaware of their infection until they are tested or develop severe complications such as infertility. It is believed that the primary culprit of Ct-associated tissue damage is unresolved chronic inflammation, resulting in aberrant production of cytokines, chemokines, and growth factors, as well as dysregulated tissue influx of innate and adaptive immune cells. A member of the IL-6 cytokine family, leukemia inhibitory factor (LIF), is one of the cytokines induced by Ct infection but its role in Ct pathogenesis is unclear. In this article, we review the biology of LIF and LIF receptor (LIFR)-mediated signaling pathways, summarize the physiological role of LIF in the reproductive system, and discuss the impact of LIF in chronic inflammatory conditions and its implication in Ct pathogenesis. Under normal circumstances, LIF is produced to maintain epithelial homeostasis and tissue repair, including the aftermath of Ct infection. However, LIF/LIFR-mediated signaling – particularly prolonged strong signaling – can gradually transform the microenvironment of the fallopian tube by altering the fate of epithelial cells and the cellular composition of epithelium. This harmful transformation of epithelium may be a key process that leads to an enhanced risk of infertility, ectopic pregnancy and cancer following Ct infection.

The inclusion membrane protein IncS is critical for initiation of the Chlamydia intracellular developmental cycle

All Chlamydia species are obligate intracellular bacteria that undergo a unique biphasic developmental cycle strictly in the lumen of a membrane bound compartment, the inclusion. Chlamydia specific Type III secreted effectors, known as inclusion membrane proteins (Inc), are embedded into the inclusion membrane. Progression through the developmental cycle, in particular early events of conversion from infectious (EB) to replicative (RB) bacteria, is important for intracellular replication, but poorly understood. Here, we identified the inclusion membrane protein IncS as a critical factor for Chlamydia development. We show that a C. trachomatis conditional mutant is impaired in transition from EB to RB in human cells, and C. muridarum mutant bacteria fail to develop in a mouse model of Chlamydia infection. Thus, IncS represents a promising target for therapeutic intervention of the leading cause of sexually transmitted infections of bacterial origin.

Development of a Psychometric Tool to Measure Community Solidarity Among Sexual Minorities: Evidence From a Pay-it-Forward Randomized Controlled Trial

BACKGROUND

Community solidarity is increasingly important in public health. However, few studies have examined solidarity in relation to health outcomes. The purpose of this study was to develop a psychometric tool to measure solidarity among Chinese men who have sex with men (MSM) and assess whether community solidarity relates to differences in sexually transmitted infection testing.

METHODS

We used data from the pay-it-forward randomized controlled trial of 301 men from Beijing and Guangzhou, China. Men who have sex with men were randomized into pay-it-forward (participants receive free gonorrhea/chlamydia testing as gifts and choose to donate toward subsequent MSM's tests), pay-what you-want, and standard payment arms. After testing decision, participants completed a cross-sectional questionnaire to assess community solidarity. Factor analysis was conducted to identify dimensions of solidarity. The solidarity factors were compared across study arms and assessed against gonorrhea/chlamydia test uptake in multivariable logistic regression.

RESULTS

Two hundred eighty-eight participants responded to the survey. We identified 3 latent community solidarity factors: engagement, social network support, and sense of belonging. Several items related to belonging were significantly greater among participants in the pay-it-forward scenario compared with those assigned to other scenarios. Higher sense of belonging was associated with higher odds of gonorrhea and chlamydia test uptake.

CONCLUSIONS

Community solidarity among MSM in China can be characterized by 3 factors: engagement, social network support, and sense of belonging. Sense of belonging was higher in the pay-it-forward intervention arm and may be associated with the uptake of gonorrhea/chlamydia test. Future studies are warranted to confirm the psychometric structure of community solidarity and further investigate behavioral mechanisms of pay it forward.

Role of TRAIL-R in Primary and Secondary Genital and Respiratory Chlamydia muridarum Infections in Mice

The tumor necrosis factor (TNF)-related apoptosis-inducing ligand receptor (TRAIL-R) suppresses inflammation and could therefore affect the course of Chlamydia infections and their long-term sequelae. Wild-type (WT) and TRAIL-R-/- C57BL/6 mice were inoculated vaginally with Chlamydia muridarum; the course of the infection was followed with vaginal cultures and the presence of hydrosalpinx determined. To evaluate the role of TRAIL-R following a secondary infection, the mice were vaginally reinfected. WT and TRAIL-R-/- male mice were also infected and reinfected in the respiratory tract, and the course of the diseases and the infections were followed. Following the primary and secondary vaginal infection, no significant differences in vaginal shedding or hydrosalpinx formation were observed between the WT and TRAIL-R-/- mice. The WT and TRAIL-R-/- mice mounted antibody responses in serum and vaginal washes that were not significantly different. After the primary and secondary intranasal infections of the male mice, changes in body weight were determined, and no significant differences were observed between the WT and TRAIL-R-/- mice. Ten days after the primary and the secondary infections, the weight of the lungs and number of C. muridarum inclusion forming units (IFU) were determined. The lungs of the WT mice weighed less compared with the TRAIL-R-/- mice following a primary infection but not after a secondary infection. No differences in the number of C. muridarum IFU in the lungs were observed between the two groups of mice. In conclusion, despite playing a role in inflammation cell-signaling pathways in vitro, TRAIL-R does not appear to play a major role in the susceptibility, clinical outcomes, or long-term sequelae of C. muridarum infections in vivo. IMPORTANCE TNF-related apoptosis-inducing ligand receptor (TRAIL-R) is involved in suppressing inflammatory responses. Bacterial pathogens such as Chlamydia spp. elicit inflammatory responses in humans following genital, ocular, and respiratory infections. The inflammatory responses are important to control the spread of Chlamydia. However, in certain instances, these inflammatory responses can produce long-term sequelae, including fibrosis. Fibrosis, or scarring, in the genital tract, eye, and respiratory system results in functional deficiencies, including infertility, blindness, and chronic obstructive lung disease, respectively. The goal of this study was to determine if mice deficient in TRAIL-R infected in the genital and respiratory tracts with Chlamydia spp. suffer more or less severe infections, infertility, or lung diseases than wild-type mice. Our results show no differences between the immune responses, infection severity, and long-term sequelae between TRAIL-R knockout and wild-type animals following a genital or a respiratory infection with Chlamydia.

Risk of Human Immunodeficiency Virus Acquisition Among High-Risk Heterosexuals With Nonviral Sexually Transmitted Infections: A Systematic Review and Meta-Analysis

BACKGROUND

Nonviral sexually transmitted infections (STIs) increase risk of sexually acquired human immunodeficiency virus (HIV) infection. Updated risk estimates carefully scrutinizing temporality bias of studies are needed.

METHODS

We conducted a systematic review (PROSPERO CRD42018084299) of peer-reviewed studies evaluating variation in risk of HIV infection among high-risk heterosexuals diagnosed with any of: Chlamydia trachomatis, Mycoplasma genitalium, Neisseria gonorrhoeae, Treponema pallidum, and/or Trichomonas vaginalis. We searched PubMed, Web of Science, and Embase databases through December 2017 and included studies where STIs and HIV were assessed using laboratory tests or medical examinations and where STI was diagnosed before HIV. After dual screening, data extraction, and risk of bias assessment, we meta-analytically pooled risk ratios (RRs).

RESULTS

We found 32 eligible studies reporting k = 97 effect size estimates of HIV acquisition risk due to infection with one of the abovementioned STIs. Most data were based on women engaged in sex work or other high-risk occupations in developing countries. Many studies did not measure or adjust for known confounders, including drug injection and condom use, and most were at medium or high risk of bias because of the potential for undetected HIV infection to have occurred before STI infection. Human immunodeficiency virus acquisition risk increased among women infected with any pathogen; the effect was greatest for women infected with Mycoplasma genitalium (RR, 3.10; 95% confidence interval [CI], 1.63-5.92; k = 2) and gonorrhea (RR, 2.81; 95% CI, 2.25-3.50; k = 16) but also statistically significant for women infected with syphilis (RR, 1.67; 95% CI, 1.23-2.27; k = 17), trichomonas (RR, 1.54; 95% CI, 1.31-1.82; k = 17), and chlamydia (RR, 1.49; 95% CI, 1.08-2.04; k = 14). For men, data were space except for syphilis (RR, 1.77; 95% CI, 1.22-2.58; k = 5).

CONCLUSION

Nonviral STI increases risk of heterosexual HIV acquisition, although uncertainty remains because of risk of bias in primary studies.

Sexually Transmitted Infections: Updates From the 2021 CDC Guidelines

Sexually transmitted infection (STI) rates are increasing for most nationally notifiable disease categories in the United States. The 2021 Centers for Disease Control and Prevention STI guidelines provide several updated, evidence-based testing and treatment recommendations. The recommended treatment for gonorrhea is ceftriaxone monotherapy given intramuscularly, with dosing based on the patient's body weight. For chlamydia, doxycycline is the preferred treatment. A test-of-cure is recommended for all cases of pharyngeal gonorrhea and for rectal chlamydia if treated with azithromycin. Vaginal trichomoniasis should be treated with a seven-day regimen of metronidazole. Treatment of pelvic inflammatory disease routinely includes metronidazole with doxycycline and an increased dosage of ceftriaxone. Syphilis of less than one year's duration should be treated with a single dose of intramuscular penicillin G benzathine, 2.4 million units. Syphilis of more than one year's or unknown duration should be treated with three consecutive weekly doses of intramuscular penicillin G benzathine, 2.4 million units each. A thorough evaluation for otic, ophthalmic, and neurologic symptoms is essential for anyone with syphilis because these complications can occur at any stage and require 10 to 14 days of treatment with intravenous aqueous crystalline penicillin G. Family physicians can reduce STI rates by taking a thorough sexual history, especially in teens and young adults, ordering screening tests and treatment based on the updated Centers for Disease Control and Prevention STI guidelines, and collaborating with public health departments for disease reporting and partner services.

Signaling Induced by Chronic Viral Hepatitis: Dependence and Consequences

Chronic viral hepatitis is a main cause of liver disease and hepatocellular carcinoma. There are striking similarities in the pathological impact of hepatitis B, C, and D, although these diseases are caused by very different viruses. Paired with the conventional study of protein-host interactions, the rapid technological development of -omics and bioinformatics has allowed highlighting the important role of signaling networks in viral pathogenesis. In this review, we provide an integrated look on the three major viruses associated with chronic viral hepatitis in patients, summarizing similarities and differences in virus-induced cellular signaling relevant to the viral life cycles and liver disease progression.

Evaluation of Urethrotropic-Clade Meningococcal Infection by Urine Metagenomic Shotgun Sequencing

Urethral infections caused by an emerging nongroupable (NG) urethrotropic clade of Neisseria meningitidis were first reported in the United States in 2015 (the "U.S. NmNG urethritis clade"). Here, we evaluate for the presence of other urethral pathogens in men with U.S. NmNG urethritis clade infection. We evaluated 129 urine specimens collected from men at a sexual health clinic, including 33 from patients with culture-confirmed or suspected urethral N. meningitidis infection and 96 specimens in which nucleic acid amplification test detected Neisseria gonorrhoeae, Chlamydia trachomatis, both pathogens, or neither pathogen. N. meningitidis was detected first by real-time PCR, followed by metagenomic shotgun sequencing of 91 specimens to identify coinfections. N. meningitidis genomes were sequenced following selective whole-genome amplification when possible. Metagenomic sequencing detected N. meningitidis in 16 of 17 specimens from culture-confirmed N. meningitidis cases, with no coinfection by other conventional urethral pathogens. Metagenomic sequencing also detected N. meningitidis in three C. trachomatis-positive specimens, one specimen positive for both N. gonorrhoeae and C. trachomatis, and nine specimens with negative N. gonorrhoeae and C. trachomatis results, eight of which had suspected Neisseria infections. N. meningitidis from culture-confirmed N. meningitidis cases belonged to the U.S. NmNG urethritis clade, while N. meningitidis identified in other specimens belonged to multiple clonal complexes. Additional urethral pathogens were predominant in non-N. meningitidis specimens, including N. gonorrhoeae, C. trachomatis, Mycoplasma genitalium, Ureaplasma urealyticum, and herpes simplex virus 2. Coinfection with other conventional urethral pathogens is rare in men with culture-confirmed U.S. NmNG urethritis clade infection and points to the strong association of this clade with disease.

Bacterial eye infections associated with sexual transmission infections: A review

The objective of this work was to collect updated information on Treponema pallidum, Chlamydia trachomatis and Neisseria gonorrhoeae, causing sexually transmitted infections (STIs) and etiological agents of eye infections, to provide relevant information on this public health problem. For this, a bibliographic review was carried out using different electronic databases such as: PubMed central, google academic, Lilacs, Scopus, Science Direct and Scielo, between March 2009 and August 2019. According to the WHO, more than a million people a day contract a sexually transmitted infection. For T. pallidum, a global prevalence of 0.5% is estimated for both men and women. It is a causative agent of syphilis and ocular syphilis, which manifests as uveitis. Overall, a prevalence of 2.8% in men and 3.8% in women for C. trachomatis is estimated. It is associated with oculo-genital disease, which includes STIs, inclusion conjunctivitis in adults and neonatal ophthalmia. Among its complications is trachoma, which is the leading cause of infectious blindness worldwide. Regarding N. gonorrhoeae, it has a global selection of 0.9% and 0.7% in women and men, respectively. It manifests with gonococcal conjunctivitis and neonatal ophthalmia. We can conclude that the information that relates T. pallidum, C. trachomatis and N. gonorrhoeae with their ocular compromise problems is insufficient, and even more so if we seek to find them related to each other, which makes it difficult to access data of clinical utility for visual health.

Modeling the Cost-Effectiveness of Express Multisite Gonorrhea Screening Among Men Who Have Sex With Men in the United States

BACKGROUND

Men who have sex with men (MSM) experience high rates of gonococcal infection at extragenital (rectal and pharyngeal) anatomic sites, which often are missed without asymptomatic screening and may be important for onward transmission. Implementing an express pathway for asymptomatic MSM seeking routine screening at their clinic may be a cost-effective way to improve extragenital screening by allowing patients to be screened at more anatomic sites through a streamlined, less costly process.

METHODS

We modified an agent-based model of anatomic site-specific gonococcal infection in US MSM to assess the cost-effectiveness of an express screening pathway in which all asymptomatic MSM presenting at their clinic were screened at the urogenital, rectal, and pharyngeal sites but forewent a provider consultation and physical examination and self-collected their own samples. We calculated the cumulative health effects expressed as gonococcal infections and cases averted over 5 years, labor and material costs, and incremental cost-effectiveness ratios for express versus traditional scenarios.

RESULTS

The express scenario averted more infections and cases in each intervention year. The increased diagnostic costs of triple-site screening were largely offset by the lowered visit costs of the express pathway and, from the end of year 3 onward, this pathway generated small cost savings. However, in a sensitivity analysis of assumed overhead costs, cost savings under the express scenario disappeared in the majority of simulations once overhead costs exceeded 7% of total annual costs.

CONCLUSIONS

Express screening may be a cost-effective option for improving multisite anatomic screening among US MSM.

Doxycycline for Sexually Transmitted Infection Prevention: Evolving Evidence and Implementation Perspectives

Editorial for Sexually Transmitted Diseases (STD20–495): Interest, concerns, and attitudes among men who have sex with men and healthcare providers toward prophylactic use of doxycycline against Chlamydia trachomatis infections and syphilis.

Sexually transmitted infections and prior antibiotic use as important causes for negative urine cultures among adults presenting with urinary tract infection symptoms to primary care clinics in Zimbabwe: a cross-sectional study

OBJECTIVE

Urinary tract infections (UTIs) are common in primary care. The yield of urine cultures in patients with UTI symptoms can be considerably different between high-income and low-income settings. This study aimed to explore possible causes of negative urine cultures in patients presenting with symptoms of UTI to primary health clinics in Harare.

DESIGN

Cross-sectional study.

SETTING

Nine primary health clinics in Harare, Zimbabwe.

PARTICIPANTS

Adults presenting with symptoms of UTIs between March and July 2020.

PRIMARY OUTCOME MEASURES

Urine samples underwent dipstick testing, microscopy, culture, and testing for sexually transmitted infections (STIs) using GeneXpert and for the presence of antibiotic residues using an antibiotic bioassay. The primary outcomes were the number and proportion of participants with evidence of STIs, prior antibiotic exposure, leucocyturia and UTIs.

RESULTS

The study included 425 participants with a median age of 37.3 years, of whom 275 (64.7%) were women. Leucocyturia was detected in 130 (30.6%, 95% CI 26.2% to 35.2%) participants, and 96 (22.6%, 95% CI 18.7% to 26.9%) had a positive urine culture for a uropathogen. Chlamydia trachomatis, Neisseria gonorrhoeae and Trichomonas vaginalis were detected in 43/425 (10.1%, 95% CI 7.4% to 13.4%), 37/425 (8.7%, 95% CI 6.2% to 11.8%) and 14/175 (8.0%, 95% CI 4.4% to 13.1%) participants, respectively. Overall, 89 (20.9%, 95% CI 17.2% to 25.1%) participants reported either having taken prior antibiotics or having had a positive urine bioassay. In 170 (40.0%, 95% CI 35.3% to 44.8%) participants, all of the tests that were performed were negative.

CONCLUSIONS

This study found a high prevalence of STIs and evidence of prior antimicrobial use as possible explanations for the low proportion of positive urine cultures.

Mycoplasma genitalium and Other Reproductive Tract Infections in Pregnant Women, Papua New Guinea, 2015-2017

Much about the range of pathogens, frequency of coinfection, and clinical effects of reproductive tract infections (RTIs) among pregnant women remains unknown. We report on RTIs (Mycoplasma genitalium, Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, Treponema pallidum subspecies pallidum, bacterial vaginosis, and vulvovaginal candidiasis) and other reproductive health indicators in 699 pregnant women in Papua New Guinea during 2015–2017. We found M. genitalium, an emerging pathogen in Papua New Guinea, in 12.5% of participants. These infections showed no evidence of macrolide resistance. In total, 74.1% of pregnant women had >1 RTI; most of these infections were treatable. We detected sexually transmitted infections (excluding syphilis) in 37.7% of women. Our findings showed that syndromic management of infections is greatly inadequate. In total, 98.4% of women had never used barrier contraception. These findings will inform efforts to improve reproductive healthcare in Papua New Guinea.

Prevalence of cervical HPV infection, sexually transmitted infections and associated antimicrobial resistance in women attending cervical cancer screening in Mali

OBJECTIVES

To assess the prevalence of sexually transmitted infections (STIs), antimicrobial resistance and cervical lesions among women from Sikasso, Mali.

METHODS

Women infected with human immunodeficiency virus (HIV) (n=44) and HIV-negative women (n=96) attending cervical cancer screening were included. Screening for human papillomavirus (HPV), Chlamydia trachomatis (CT), Mycoplasma genitalium (MG), Neisseria gonorrhoeae (NG) and Trichomonas vaginalis (TV) was performed using polymerase chain reaction assays, and herpes simplex virus (HSV-1/2) serological status was assessed using enzyme-linked immunosorbent assays. Antibiotic resistance tests were performed for MG- and NG-positive cases.

RESULTS

A high prevalence of high-risk HPV (hrHPV) infection (63%) was found. This was associated with cervical lesions in 7.5% of cases. An unusual distribution was found, with HPV31, HPV56 and HPV52 being the most prevalent. The hrHPV distribution differed by HIV status, with HIV-positive cases having HPV35/31/51-52-56 and HIV-negative cases having HPV31/56/52. The seroprevalence of HSV-2 was 49%, and the prevalence of other STIs was as follows: CT, 4%; MG, 9%; NG, 1%; and TV, 7%. Five of nine MG-positive specimens and the NG strains obtained were resistant to fluoroquinolone.

CONCLUSIONS

These results showed high prevalence of hrHPV and fluoroquinolone resistance in several NG and MG strains. Further studies are required to confirm these data in Mali, and to improve prevention, screening and management of cervical cancer and other STIs in women.