Chlamydia Research Articles

Prevalence of sexually transmitted infection in pregnancy and their association with adverse birth outcomes: a case–control study at Queen Elizabeth Central Hospital, Blantyre, Malawi

BackgroundThere are limited data on the epidemiology of sexually transmitted infections (STI) and their contribution to adverse birth outcomes (ABO) in sub-Saharan Africa (SSA). We performed a case–control study to...

Evaluation of Anti‐Chlamydial Effect of a Synthetic Linear Peptide

AbstractInspired by the broad spectrum of antimicrobial activity exhibited by Magainins and SMAP‐28, and based on their chemical structures, several linear peptides were designed and synthesized with the aim of achieving peptides possessing promising anti‐chlamydial activity with lower cytotoxicity towards human normal cell lines. We found these peptides to be cytotoxic against human normal cell lines, except for one designated as DJ‐7, which was utilized in subsequent experiments, while the others were excluded. Peptide DJ‐7 was readily synthesized using standard Fmoc‐SPPS, and its anti‐chlamydial activity was investigated against HeLa cells (ATCC CCL‐2) infected with Chlamydia trachomatis L2 (ATCC VR‐902B) at MOI 1 for 2 hours, followed by treatment with increasing concentrations of peptide DJ‐7 (15–60 μg/mL). Microscopic examination revealed a significant reduction in the total number of bacterial inclusions in cells by around 50 % and 80 % after treatment with 15 μg/mL (5.5 μM) and 30 μg/mL (11 μM) of peptide DJ‐7, respectively, compared to control untreated infected cells. The impact of peptide DJ‐7 treatment on the development of infectious C. trachomatis serovar L2 progeny was investigated, demonstrating a significant decrease in infectious chlamydia after treatment with peptide DJ‐7. This suggests that chlamydia failed to complete its typical developmental cycle, indicating that peptide DJ‐7 exhibits anti‐chlamydial properties, by disrupting the normal bacterial development process. Our results indicate that peptide DJ‐7 is a promising lead peptide for further development as a potential anti‐chlamydial agent.

The vaginal microbiome of South African pregnant women living with human immunodeficiency virus (HIV) with and without Chlamydia trachomatis infection

BackgroundChlamydia genital infections continue to be a serious health concern globally. Previous studies have reported that Chlamydia trachomatis infection alters the vaginal microbiota of infected women. This study investigated differences in the vaginal microbiome of South African pregnant women living with HIV with and without C. trachomatis infection.MethodsThis was a cross-sectional study among 385 pregnant women, recruited from the King Edward VIII Hospital in Durban, South Africa. C. trachomatis was detected using the Applied Biosystems™ TaqMan® Assays. A total of 40 samples, 20 C. trachomatis positive and 20 C. trachomatis negative, were selected for sequencing. The sequencing of the vaginal microbiome was performed using the PacBio platform. Statistical analysis was performed on IBM SPSS version 26.ResultsThe prevalence of C. trachomatis infection was 12.2% (47/385). The genus Gardnerella (32.14% vs. 24.02%) and species in the genus Gardnerella (31.97% vs. 24.03%) were more abundant in the C. trachomatis-infected group compared to the uninfected group. Lactobacillus iners were also more abundant in the C. trachomatis-infected women (28.30%) compared to the uninfected women. However, these observed patterns did not reach statistical significance. Discriminant analysis showed that the class Alpha-Proteobacteria; order Bacillales; family Enterococcaceae; the genera Enhydrobacter, Enterococcus, and Parabacteroides; Enterococcus spp.; and Pseudomonas stutzeri significantly contributed to a model separating C. trachomatis-infected women from the uninfected group (p < 0.05).ConclusionThe organisms and taxa that significantly contributed to separating the vaginal microbiota of C. trachomatis-infected women from the uninfected women in this study cohort have not been previously observed in association with C. trachomatis infection or the vaginal microbiota. Future studies in larger cohorts that will investigate the role of these microorganisms in C. trachomatis infection and the vaginal microbiota are required.

Successful treatment of cicatricial stenosis of the main, intermediate and upper lobe bronchi of the right lung complicated by total lung atelectasis in an infant: a clinical case

BACKGROUND: The authors present a rare clinical case of stenosis of the main, intermediate and upper lobe bronchi of the right lung complicated by total lung atelectasis in an infant. They discuss issues of complex disease diagnostics, analyze X-ray and bronchological images, assess outcomes after multidisciplinary approach in the treatment of a premature baby as well as analyze data of catamnestic observation. CLINICAL CASE DESCRIPTION: Girl T., one of monochorionic diamniotic twins, was born at 27 week gestation in 2021 with weight at birth 825 grams, Apgar score 4/5. Since her birth, she had artificial lung ventilation due to her deep immaturity and developed severe respiratory distress syndrome. At the age of 19 days, total atelectasis of the right lung was diagnosed in the child as a result of stenosis formation in the main, intermediate and upper lobe bronchi which was confirmed by clinical and radiological findings. A probable etiology of acquired stenosis is consequences of prolonged intubation under insufficiently formed cartilaginous framework. Chlamydial infection, detected in the child, could also support inflammatory process in the bronchi. The child was examined with the following instruments: radiography, multispiral computed tomography-angiography of the thoracic cavity, bronchofibroscopy, echocardiography. Laboratory tests: polymerase chain reaction of blood and sputum for herpes viruses type 1–6, mycoplasma, ureaplasma, Chlamydia pneumonia; blood enzyme immunoassays — antibodies to viruses of Herpesviridae type 1–6, Chlamydia trachomatis. Conservative therapy provided only temporal improvement; atelectasis was relapsing. At the age of 5 months and 20 days, the child underwent bronchoplasty with resection of damaged areas of the bronchi. Further, age-related diameter of the bronchial lumen was maintained by the staged bougienage. Catamnestic observation lasted for 3 years. Late timing of surgical intervention is explained by severe problems in a deeply premature and immature child that required immediate treatment (intraventricular hemorrhages, hydrocephalus, retinopathy, etc.). Effective surgical treatment (bronchoplasty), active growth of lung tissue at the first year of life as well as reasonable rehabilitation allowed to obtain good long-term outcomes. By the age of 1 year 2 months, normalization of right lung airiness was achieved. Currently, there is a slight reduction in right lung volume. Multispiral computed tomography-angiography revealed a few cylindrical bronchoectases in the segmental and subsegmental bronchi of the upper and middle lobes of the right lung which do not have clinical equivalents yet. The child is under pulmonologist's observation and management. CONCLUSION: A multidisciplinary approach to the treatment of complicated patient's state and high compensatory capabilities of neonatal and infantile periods have promoted the restoration of normal lung aeration and functioning after long-lasting lung atelectasis

Photographic grading to evaluate facial cleanliness and trachoma among children in Amhara region, Ethiopia.

Promotion of facial cleanliness is recommended for the elimination of blinding trachoma, largely because of observational studies that have found an association between various measures of facial uncleanliness and trachoma. However, when a field grader assesses both facial cleanliness and trachoma, associations may be biased. Assessment of photographs of the face and conjunctiva by masked graders may provide a less biased estimate of the relationship between facial cleanliness and trachoma. Face photographs, conjunctival photographs, and conjunctival swabs were obtained on a random sample of 0-9-year-old children from each of 40 communities in Amhara region, Ethiopia. Face photographs were assessed for the presence of seven measures of an unclean face (i.e., wet nasal discharge, dry nasal discharge, wet ocular discharge, dry ocular discharge, food, dust/dirt, and flies) by three independent masked photo-graders. Conjunctival photographs were similarly graded in a masked fashion for signs of clinically active trachoma. Conjunctival swabs were processed for Chlamydia trachomatis DNA. Of 2073 children with complete data, 808 (39%) had evidence of clinically active trachoma, 150 (7%) had evidence of ocular chlamydia infection, and 2524 (91%) had at least one measure of an unclean face. Dry ocular discharge had the strongest association with clinically active trachoma (age- and sex-adjusted prevalence ratio [PR] 1.4, 95% CI 1.2-1.6) and ocular chlamydia infection (PR 1.9, 95%CI 1.3-2.9), although significant associations were observed between each of the measures of facial uncleanliness and trachoma. Masked assessment of face and conjunctival photographs confirmed prior observational studies that have noted associations between various measures of facial uncleanliness and trachoma. The causal relationship between facial uncleanliness and trachoma is unclear since many features used to measure facial cleanliness (e.g., ocular discharge, nasal discharge, and flies) could be consequences of antecedent ocular chlamydia infection. NCT02754583, clinicaltrials.gov.

Are Chlamydia Trachomatis and Neisseria Gonorrhoeae Screenings in Pregnant Women Being Properly Performed? A Single-Center Retrospective Observational Study in Italy.

A new Italian intersociety position statement on the prevention of ophthalmia neonatorum was published in 2023. In this document, attention was paid to the indications for the screening of gonococcal and chlamydial infections during pregnancy according to the international and national guidelines for the prevention of sexually transmitted infections (STIs). We conducted an observational retrospective study to assess whether the current guidelines for the prevention of STIs are being followed correctly. From February to August 2022, 2507 women nearing childbirth were enrolled. Among them, 42.4% received a swab for Chlamydia and only 0.5% for gonococcus. Concerning the geographical area of origin, most of the screened women came from Western Europe. None of the women who received gonococcal swabs and only 105 women out of 1062 screened for Chlamydia were under 25 years of age. Overall, only seven swabs were positive for Chlamydia, while none were positive for gonococcus. Concerning the age, geographical area of origin, and medical history of the women with a positive screening for Chlamydia, all were over 25 years old, six were from Western Europe, one was from South America, and none had other STIs. Although monocentric in nature, this study shows that the guidelines are not being followed correctly.

Viral-vectored boosting of OmcB- or CPAF-specific T-cell responses fail to enhance protection from Chlamydia muridarum in infection-immune mice and elicits a non-protective CD8-dominant response in naïve mice

A vaccine is needed to combat the Chlamydia epidemic. Replication-deficient viral vectors are safe and induce antigen-specific T cell memory. We tested the ability of intramuscular immunization with modified vaccinia virus Ankara (MVA) or Chimpanzee Adenovirus (ChAd) expressing chlamydial outer membrane protein, OmcB, or the secreted protein, CPAF, to enhance T cell immunity and protection in mice previously infected with plasmid-deficient Chlamydia muridarum CM972, and to elicit protection in naïve mice. MVA.OmcB or MVA.CPAF increased antigen-specific T cells in CM972-immune mice ∼150 and 50-fold respectively but failed to improve bacterial clearance. ChAd.OmcB/MVA.OmcB prime-boost immunization of naïve mice elicited a CD8-dominant T cell response that failed to protect. ChAd.CPAF/ChAd.CPAF prime-boost also induced a CD8-dominant response with a marginal reduction in burden. Challenge of ChAd.CPAF-immunized mice genetically deficient in CD4 or CD8 T cells showed that protection was entirely CD4-dependent. CD4-deficient mice had prolonged infection, while CD8-deficient mice had higher frequencies of CPAF-specific CD4 T cells, earlier clearance, and reduced burden compared to wild-type controls. These data reinforce the essential nature of the CD4 T cell response in protection from chlamydial genital infection in mice and the need for vaccine platforms that drive CD4-dominant responses.

The Epidemiology of Ocular Chlamydia trachomatis Infection within Districts Persistently Endemic for Trachoma in Amhara, Ethiopia.

Persistent trachoma is a growing concern to trachoma control programs globally and programs serving Ethiopia specifically. Persistent trachoma is defined as a district with two or more trachoma impact surveys (TISs) at which the prevalence of trachomatous inflammation-follicular (TF) among children ages 1-9 years is ≥5%, the elimination threshold. Because the global target for trachoma elimination as a public health problem is 2030, research is needed to better characterize persistent trachoma. This study described the epidemiology of ocular Chlamydia trachomatis infection, the causative bacteria of trachoma, in seven contiguous districts experiencing persistent trachoma. In 2019, multistage cluster random sampling TISs were conducted in the seven districts after 10 years of interventions. All individuals ages ≥1 year were examined for trachoma clinical signs by certified graders, and conjunctival swabs were collected from children ages 1-5 years to test for C. trachomatis infection. The district TF prevalence ranged from 11.8% (95% CI:7.6-16.0%) to 36.1% (95% CI:27.4-44.3%). The range of district-level C. trachomatis infection prevalence was between 2.7% and 34.4%. Statistically significant spatial clustering of high-infection communities was observed in the study districts, and children with infection were more likely than those without to be found in households with clinical signs of trachoma and those without latrines. These seven districts appear to constitute a persistent hotspot in Amhara, where an additional 3-5 years or more of interventions will be required. The global program will need to strengthen and enhance intervention strategies within persistent districts if elimination by 2030 is to be achieved.

Combination of compound screening with an animal model identifies pentamidine to prevent Chlamydia trachomatis infection

Chlamydia trachomatis (Ct) is the most common cause for bacterial sexually transmitted infections (STIs) worldwide with a tremendous impact on public health. With the aim to unravel novel targets of the chlamydia life cycle, we screen a compound library and identify 28 agents to significantly reduce Ct growth. The known anti-infective agent pentamidine-one of the top candidates of the screen-shows anti-chlamydia activity in low concentrations by changing the metabolism of host cells impairing chlamydia growth. Furthermore, it effectively decreases the Ct burden upon local or systemic application in mice. Pentamidine also inhibits the growth of Neisseria gonorrhea (Ng), which is a common co-infection of Ct. The conducted compound screen is powerful in exploring antimicrobial compounds against Ct in a medium-throughput format. Following thorough invitro and invivo assessments, pentamidine emerges as a promising agent for topical prophylaxis or treatment against Ct and possibly other bacterial STIs.

Prevalence and Impact of Chlamydia trachomatis Infection in Primary and Secondary Infertile Women of Kurdish Ethnicity in Erbil Provence- Iraq

Prevalence and Impact of Chlamydia trachomatis Infection in Primary and Secondary Infertile Women of Kurdish Ethnicity in Erbil Provence- Iraq

Insights into Chlamydia Development and Host Cells Response.

Chlamydia infections commonly afflict both humans and animals, resulting in significant morbidity and imposing a substantial socioeconomic burden worldwide. As an obligate intracellular pathogen, Chlamydia interacts with other cell organelles to obtain necessary nutrients and establishes an intracellular niche for the development of a biphasic intracellular cycle. Eventually, the host cells undergo lysis or extrusion, releasing infectious elementary bodies and facilitating the spread of infection. This review provides insights into Chlamydia development and host cell responses, summarizing the latest research on the biphasic developmental cycle, nutrient acquisition, intracellular metabolism, host cell fates following Chlamydia invasion, prevalent diseases associated with Chlamydia infection, treatment options, and vaccine prevention strategies. A comprehensive understanding of these mechanisms will contribute to a deeper comprehension of the intricate equilibrium between Chlamydia within host cells and the progression of human disease.

Tracking Chlamydia – Host interactions and antichlamydial activity in Caenorhabditis elegans

The fading efficacy of antibiotics is a growing global health concern due to its life-threatening consequences and increased healthcare costs. Non-genetic mechanisms of antimicrobial resistance, such as those employed by Chlamydia pneumoniae and Chlamydia trachomatis, complicate treatment as these bacteria can enter a non-replicative, persistent state under stress, evading antibiotics and linking to inflammatory conditions. Understanding chlamydial persistence at the molecular level is challenging, and new models for studying Chlamydia-host interactions in vivo are urgently needed. Caenorhabditis elegans offers an alternative given its immune system and numerous orthologues of human genes. This study established C. elegans as an in vivo model for chlamydial infection. Both Chlamydia species reduced the worm's lifespan, their DNA being detectable at three- and six-days post-infection. Azithromycin at its MIC (25 nM) failed to prevent the infection-induced lifespan reduction, indicating a persister phenotype. In contrast, the methanolic extract of Schisandra chinensis berries showed anti-chlamydial activity both in vitro (in THP-1 macrophages) and in vivo, significantly extending the lifespan of infected C. elegans and reducing the bacterial load. Moreover, S. chinensis increased the transcriptional activity of SKN-1 in the worms, but was unable to impact the bacterial load or lifespan in a sek-1 defective C. elegans strain. In summary, this study validated C. elegans as a chlamydial infection model and showcased S. chinensis berries' in vivo anti-chlamydial potential, possibly through SEK/SKN-1 signaling modulation.

The role of bacterial genital infections in spontaneous preterm delivery: a case-control study.

Spontaneous preterm delivery is defined as the beginning of the birth process before the 37th week of pregnancy. The presence of microorganisms in the fetal membranes is accompanied by an increase in the production of prostaglandin, one of the important factors associated with the prevalence of preterm birth. The invasion of microorganisms leads to the production of protease, coagulase, and elastase, which directly stimulate the onset of childbirth. We investigated the role of genital infections in women with preterm birth. The present case-control study was conducted in the west of Iran on 100 women with spontaneous preterm delivery (following 24 weeks of gestation and before 36 weeks and 6 days) as the case group and 100 women with normal delivery as controls. A questionnaire was applied to collect the data. Polymerase chain reaction and pathological examination of the placenta were performed. The average age in women with normal delivery (30.92 ± 5.10) in women with spontaneous preterm delivery (30.27 ± 4.93). The prevalence of Chlamydia trachomatis, Neisseria gonorrhea, Listeria monocytogenes, and Mycoplasma genitalium infections was zero in both groups. The highest prevalence of Gardnerella vaginalis was 19 (19%) in the case group and Ureaplasma parvum 15 (15%) in the control group. Also, Placental inflammation was zero in controls and 7(7%) in the patient group. There was a significant relationship between Gardnerella vaginalis bacteria and spontaneous preterm delivery. The results of our study showed that except for Gardnerella vaginalis bacteria, there is no significant relationship between the above bacterial infections and spontaneous preterm birth. Moreover, despite the significant reduction in the prevalence of many sexually transmitted infections in this research, it is still suggested to increase the awareness of people, including pregnant women, about the ways it can be transmitted by gynecologists and health and treatment centers.

Chlamydia trachomatis induces disassembly of the primary cilium to promote the intracellular infection.

Chlamydia trachomatis is a clinically important bacterium that infects epithelial cells of the genitourinary and respiratory tracts and the eye. These differentiated cells are in a quiescent growth state and have a surface organelle called a primary cilium, but the standard Chlamydia cell culture infection model uses cycling cells that lack primary cilia. To investigate if these differences are relevant, we performed infections with host cells that have a primary cilium. We found that C. trachomatis caused progressive loss of the primary cilium that was prevented by disrupting Aurora A (AurA), HDAC6 or calmodulin, which are components of the cellular cilia disassembly pathway. Stabilization of the primary cilium by targeting this pathway caused a large reduction in infectious progeny although there were no changes in chlamydial inclusion growth, chlamydial replication or the ultrastructural appearance of dividing and infectious forms (RBs and EBs, respectively). Thus, the presence of a primary cilium interfered with the production of infectious EBs at a late step in the developmental cycle. C. trachomatis infection also induced quiescent cells to re-enter the cell cycle, as detected by EdU incorporation in S-phase, and Chlamydia-induced cilia disassembly was necessary for cell cycle re-entry. This study therefore describes a novel host-pathogen interaction in which the primary cilium limits a productive Chlamydia infection, and the bacterium counteracts this host cell defense by activating the cellular cilia disassembly pathway.

An In vitro Model of Chlamydia trachomatis Infection in Human Dendritic Cells

Chlamydia trachomatis (CT) is an obligate intracellular bacterial pathogen known to cause trachoma, sexually transmitted infections, and reactive arthritis. The more serious sequelae of these diseases, blindness from trachoma and pelvic inflammatory disease from chlamydial STD are immunopathological responses to chronic infections. With the abundance of dendritic cells in CT infection sites and their central importance in immune regulation, the susceptibility of dendritic cells to CT infection was investigated in vitro. CT (serovar F) was grown and extracted from HeLa 229 cells for infection of human dendritic cells (DCs). Human DCs were generated from peripheral blood mononuclear cells in the presence of GM-CSF and IL-4. Infected DCs were harvested at 0, 4, 24, and 48 h after infection and immunostained. Results from fluorescence microscopy showed that DC can be infected and can support the growth of CT in vitro. Intracellular elementary and reticulate bodies of CT were detected, and reticulate bodies were shown to multiply over the 48 h-cycle in DC. At 48 h, intracellular elementary bodies were detected in some DCs. These results may provide new insights into the possible participation of DC in sustaining chronic or latent infection, or even dissemination of CT infection to other sites

Prevalence and trends of Chlamydia trachomatis infection in female sex workers and men who have sex with men in China: a systematic review and meta-analysis

IntroductionChlamydia trachomatis infection can cause a significant disease burden in high-risk populations. This study aimed to assess the overall prevalence of C. trachomatis infection, and determine the long-term trends and geographic distribution of this infection among female sex workers (FSWs) and men who have sex with men (MSM) in China.MethodsThe PubMed, Web of Science, CNKI, Wanfang Data and VIP databases were searched from 1 January 1990 through 30 April 2023. Publications in which C. trachomatis infection was detected using nucleic acid amplification tests (NAATs) were included. The Q test and I2 statistics were used to assess the heterogeneity between studies. A random-effect model was used to estimate the pooled prevalence of C. trachomatis infection. Subgroup, meta-regression, and sensitivity analyses were performed to explore the sources of heterogeneity. Publication bias was evaluated using Egger’s test. Trend analysis of the prevalence was performed using the Jonckheere-Terpstra trend test method.ResultsSixty-one studies were eligible for inclusion (including 38 for FSWs and 23 for MSM). The pooled prevalence of C. trachomatis infection was 19.5% (95% CI: 16.4, 23.0) among FSWs and 12.7% (95% CI: 9.2, 17.7) in the rectum, 6.4% (95% CI: 5.3, 7.8) in the urethra and 1.3% (95% CI: 0.8, 2.1) in the oropharynx from MSM in China. The subgroup analyses showed that the sample size, study period, study region, specimen collection type, molecular diagnosis method, and recruitment site could explain some heterogeneity among studies of FSWs, and the publication language, study period, study region, molecular diagnosis method, and specimen collection anatomical site could explain some heterogeneity among studies of MSM. From 1998 to 2004, 2005 to 2009, 2010 to 2015, and 2016 to 2021, the pooled prevalence of C. trachomatis infection among FSWs were 30.3%, 19.9%, 21.4%, and 11.3%, respectively. For MSM, the pooled prevalence from 2003 to 2009, 2010 to 2015, and 2016 to 2022 were 7.8%, 4.7%, and 6.5%, respectively. However, no overall decline in the prevalence of C. trachomatis infection was observed among FSWs (z = -1.51, P = 0.13) or MSM (z = -0.71, P = 0.48) in China.ConclusionsThe prevalence of C. trachomatis infection was high in these two high-risk populations in China. The findings of this study provide evidence for the formulation of effective surveillance and screening strategies for the prevention and control of C. trachomatis infection among these two specific populations.

Testing trends and co-testing patterns for HIV, hepatitis C and sexually transmitted infections (STIs) in Emergency departments

BackgroundMany underserved populations use Emergency Department (EDs) as primary sources of care, representing an important opportunity to provide infectious disease testing and linkage to care. We explored national ED testing trends and co-testing patterns for HIV, hepatitis C, and sexually transmitted infections (STIs). MethodsWe used 2010–2019 Healthcare Cost and Utilization Project, Nationwide Emergency Department Sample data to estimate ED visit testing rates for HIV, hepatitis C, chlamydia, gonorrhea, and syphilis infections, identified by Current Procedural Terminology codes. Trends and co-testing (visit with tests for > 1 infection) patterns were analyzed by sociodemographic, hospital, and visit characteristics. Trends were evaluated as the average annual percentage change (AAPC) using the Joinpoint Regression. ResultsDuring 2010–2019, testing events per 1000 visits (AAPCs) increased for HIV from 1.3 to 4.2 (16.3 %), hepatitis C from 0.4 to 2.2 (25.1 %), chlamydia from 9.1 to 16.0 (6.6 %), gonorrhea from 8.4 to 15.7 (7.4 %), and syphilis from 0.7 to 2.0 (12.9 %). Rate increases varied by several characteristics across infections. The largest AAPC increases were among visits by groups with lower base rate testing in 2010, including persons aged ≥ 65 years (HIV: 36.4 %), with Medicaid (HIV: 43.8 %), in the lowest income quintile (hepatitis C: 36.9 %), living in the West (syphilis: 49.4 %) and with non-emergency diagnoses (hepatitis C: 44.1 %). Co-testing increased significantly for all infections except hepatitis C. ConclusionsHIV, hepatitis C, and STI testing increased in EDs during 2010–2019; however, co-testing patterns were inconsistent. Co-testing may improve diagnosis and linkage to care, especially in areas experiencing higher rates of infection.

Anti-chlamydial activity of vaginal fluids: new evidence from an in vitro model.

We assessed the in vitro anti-chlamydial activity of fresh vaginal secretions, deciphering the microbial and metabolic components able to counteract Chlamydia trachomatis viability. Forty vaginal samples were collected from a group of reproductive-aged women and their anti-chlamydial activity was evaluated by inhibition experiments. Each sample underwent 16S rRNA metabarcoding sequencing to determine the bacterial composition, as well as 1H-NMR spectroscopy to detect and quantify the presence of vaginal metabolites. Samples characterized by a high anti-chlamydial activity were enriched in Lactobacillus, especially Lactobacillus crispatus and Lactobacillus iners, while not-active samples exhibited a significant reduction of lactobacilli, along with higher relative abundances of Streptococcus and Olegusella. Lactobacillus gasseri showed an opposite behavior compared to L. crispatus, being more prevalent in not-active vaginal samples. Higher concentrations of several amino acids (i.e., isoleucine, leucine, and aspartate; positively correlated to the abundance of L. crispatus and L. jensenii) lactate, and 4-aminobutyrate were the most significant metabolic fingerprints of highly active samples. Acetate and formate concentrations, on the other hand, were related to the abundances of a group of anaerobic opportunistic bacteria (including Prevotella, Dialister, Olegusella, Peptostreptococcus, Peptoniphilus, Finegoldia and Anaerococcus). Finally, glucose, correlated to Streptococcus, Lachnospira and Alloscardovia genera, emerged as a key molecule of the vaginal environment: indeed, the anti-chlamydial effect of vaginal fluids decreased as glucose concentrations increased. These findings could pave the way for novel strategies in the prevention and treatment of chlamydial urogenital infections, such as lactobacilli probiotic formulations or lactobacilli-derived postbiotics.

Evaluation in mice of cell-free produced CT584 as a Chlamydia vaccine antigen.

Chlamydia trachomatis is the most prevalent bacterial sexually transmitted pathogen worldwide. Since chlamydial infection is largely asymptomatic with the potential for serious complications, a preventative vaccine is likely the most viable long-term answer to this public health threat. Cell-free protein synthesis (CFPS) utilizes the cellular protein manufacturing machinery decoupled from the requirement for maintaining cellular viability, offering the potential for flexible, rapid, and de-centralized production of recombinant protein vaccine antigens. Here, we use CFPS to produce the putative chlamydial type three secretion system (T3SS) needle-tip protein, CT584, for use as a vaccine antigen in mouse models. High-speed atomic force microscopy (HS-AFM) imaging and computer simulations confirm that CFPS-produced CT584 retains a native-like structure prior to immunization. Female mice were primed with CT584 adjuvanted with CpG-1826 intranasally (i.n.) or CpG-1826 + Montanide ISA 720 intramuscularly (i.m.), followed four-weeks later by an i.m. boost before respiratory challenge with 104 inclusion forming units (IFU) of Chlamydia muridarum. Immunization with CT584 generated robust antibody responses but weak cell mediated immunity and failed to protect against i.n. challenge as demonstrated by body weight loss, increased lungs' weights and the presence of high numbers of IFUs in the lungs. While CT584 alone may not be the ideal vaccine candidate, the speed and flexibility with which CFPS can be used to produce other potential chlamydial antigens makes it an attractive technique for antigen production.

CDC Clinical Guidelines on the Use of Doxycycline Postexposure Prophylaxis for Bacterial Sexually Transmitted Infection Prevention, United States, 2024.

No vaccines and few chemoprophylaxis options exist for the prevention of bacterial sexually transmitted infections (STIs) (specifically syphilis, chlamydia, and gonorrhea). These infections have increased in the United States and disproportionately affect gay, bisexual, and other men who have sex with men (MSM) and transgender women (TGW). In three large randomized controlled trials, 200 mg of doxycycline taken within 72 hours after sex has been shown to reduce syphilis and chlamydia infections by >70% and gonococcal infections by approximately 50%. This report outlines CDC's recommendation for the use of doxycycline postexposure prophylaxis (doxy PEP), a novel, ongoing, patient-managed biomedical STI prevention strategy for a selected population. CDC recommends that MSM and TGW who have had a bacterial STI (specifically syphilis, chlamydia, or gonorrhea) diagnosed in the past 12 months should receive counseling that doxy PEP can be used as postexposure prophylaxis to prevent these infections. Following shared decision-making with their provider, CDC recommends that providers offer persons in this group a prescription for doxy PEP to be self-administered within 72 hours after having oral, vaginal, or anal sex. The recommended dose of doxy PEP is 200 mg and should not exceed a maximum dose of 200 mg every 24 hours.Doxy PEP, when offered, should be implemented in the context of a comprehensive sexual health approach, including risk reduction counseling, STI screening and treatment, recommended vaccination and linkage to HIV PrEP, HIV care, or other services as appropriate. Persons who are prescribed doxy PEP should undergo bacterial STI testing at anatomic sites of exposure at baseline and every 3-6 months thereafter. Ongoing need for doxy PEP should be assessed every 3-6 months as well. HIV screening should be performed for HIV-negative MSM and TGW according to current recommendations.