Ct Infection Research Articles

Exploring the prevalence of chlamydial and gonorrheal infections in pregnant women: a multicenter study in Egypt

BackgroundChlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) are widespread, treatable sexually transmitted infections (STIs) of global significance, affecting millions annually. Left untreated, they pose significant risks, including pelvic inflammatory disease (PID), infertility, and complications during pregnancy. The U.S. Centers for Disease Control recommends annual chlamydial screening for sexually active women to address these risks. Responding to this global challenge, the World Health Organization (WHO) has formulated a global health sector strategy on sexually transmitted infections, outlining priority actions to strengthen STI responses in countries. However, STI epidemiological studies encounter challenges in developing nations like Egypt due to socio-cultural factors, poverty, and limited diagnostic facilities. In Egypt, STI diagnosis primarily relies on clinical presentations, lacking structured screening programs for CT and NG. This study’s main objective is to estimate the prevalence of Chlamydial and gonorrheal infections, advocating for supportive STI strategies in Egypt. Additionally, the study aims to provide a foundation for national prevalence estimates of CT and NG infections.MethodsA cross-sectional study encompassed five antenatal clinics in different regions of Egypt. A total of 1040 pregnant women attending these clinics were consecutively sampled. Data collection involved structured questionnaires, and urine samples were subjected to the GeneXpert CT/NG qualitative real-time PCR test.ResultsThe prevalence of CT infections was 0.29% (95% CI, 0.10–0.86%), with no detected NG infections. The three CT-positive cases were distributed across different recruitment centers, with no statistically significant differences observed between infected and non-infected participants. Notably, 40.3% of recruited women reported gynecological symptoms, primarily discharge. Additionally, 9.6% had undergone previous testing for sexually transmitted infections, with 8.2% receiving positive results.ConclusionsThis study provides valuable data on the prevalence of CT and NG infections among pregnant women attending ANC clinics in Egypt. The findings underscore the importance of ongoing surveillance, routine screening, and targeted interventions to ensure the reproductive health and well-being of pregnant women and their infants. Further research is warranted to explore the broader implications of STIs in different populations and to inform evidence-based guidelines for screening and management in diverse settings. Trial registration: IRB no.: 17,400,017; WHO ERC Protocol Id. A66005.

Young, deprived women are more at risk of testing positive for Chlamydia Trachomatis: results from a cross-sectional multicentre study in French Health Examination Centres.

ObjectivesChlamydia Trachomatis (CT) is the most sexually transmitted infection in France. This study aimed to assess the feasibility of systematic screening for CT among people attending a preventive health examination in Health Examination Centres (HECs) and to compare positive CT cases according to deprivation. DesignA cross-sectional multicentre study in thirteen HECs in France in January 2018. MethodsSelf-sampling CT screening was proposed among 18-25 years women and 18-30 years men, who were sexually active and without recent CT treatment. Related data and referred specimens were collected among attendees for the study, including deprivation and health status. CT positivity was estimated by genders. We explored association between CT infection and deprivation by univariate and multivariate modelling. ResultsThe CT screening was proposed to 1701 eligible young people. 90.1% [88.6-91.5] accepted and participated with 43.6% being women, 54.3% being deprived people. 75.4% [72.1-78.6] screened women performed self-taken vaginal swabs and others took urinary tests. Screening was conducted in 1486 people. Overall prevalence of CT infection was 4.7% [3.7%-5.9%], significantly higher for women than men (6.4% vs 3.4%, p=0.009). Among women, being deprived increased the likelihood of CT positivity (aOR 4.95; 95% CI 2.02 to 12.00) more than it did for men. ConclusionsIndividual deprivation was significantly associated with having a CT infection among women. The feasibility of CT screening in HECs was demonstrated, with a high acceptance, and led to the implementation of CT screening in all HECs. Promoting access to CT screening to deprived population might contribute to reduce social inequalities in health.

Analysis of genital chlamydia and gonococcal infections in infertility

To analyze the infection of chlamydia (CT) and gonorrhea (NG) in female infertility and male infertility population, and to explore the correlation between CT and NG infection and infertility. A case-control study was conducted to retrospectively analyze the specimens submitted by patients from the Third Xiangya Hospital of Central South University from January 2021 to December 2022. The results showed that a total of 32 184 specimens were collected, and the positive rates of CT were 4.41% (1 419/32 184), and positive rats of NG were 1.42% (457/32 184). In the infertility group (n=3 366), 2 987 were females and 379 were males. In the control group (n=3 366), 2 509 were females and 857 were males. The CT positive rate of the infertility group was 13.61% (458/3 366), which was significantly higher than that of the control group 3.30% (111/3 366), and the difference was statistically significant (χ2=4.245, P<0.05), and the NG positive rate of the infertility group was 6.36% (214/3 366), which was significantly higher than that of the control group 0.89% (30/3 366), and the difference was statistically significant (χ2=4.011, P<0.05). A total of 23 992 female genital tract swab specimens were collected, including 2 987 in the infertility group and 2 509 in the control group, and the positive rate of CT in the female infertility subgroup was 10.41% (311/2 987), which was significantly higher than that in the control group 3.75% (94/2 509), the difference was statistically significant (χ2=4.132, P<0.05), and the NG positive rate of 8.73% (261/2 987) in the female infertility subgroup was significantly higher than that in the control group 0.40% (10/2 509), and the difference was statistically significant (χ2=4.242, P<0.05). A total of 8 192 male urine samples were collected, including 379 in the infertility group and 857 in the control group, and the CT positive rate of the male infertility subgroup was 13.72% (52/379), which was significantly higher than that of the control group 3.38% (29/857), and the difference was statistically significant (χ2=5.267, P<0.05), and the positive rate of NG in the male infertility subgroup was 12.66% (48/379), which was significantly higher than that of the control group 0.93% (8/857), and the difference was statistically significant (χ2=4.166, P<0.05). Among the 2 987 female specimens in the infertility group, 1 034 were in the primary infertility subgroup and 1 953 were in the secondary infertility subgroup, and the positive rates of CT were 7.93% (82/1 034) and 15.72% (307/1 953), respectively, and the positive rates of NG were 3.87% (40/1 034) and 8.65% (169/1 953) respectively, and the difference was not statistically significant (χ2=0.185, P>0.05) and (χ2=0.002, P>0.05). In conclusion, the infection rate of genital tract CT and NG is high in the infertility population, CT and NG are recommended as routine examination indicators for eugenics and infertility screening.

Multimodal mucosal and systemic immune characterization of a non-human primate trachoma model highlights the critical role of local immunity during acute phase disease.

Trachoma is a leading cause of infection-related blindness worldwide. This disease is caused by recurrent Chlamydia trachomatis (Ct) infections of the conjunctiva and develops in two phases: i) active (acute trachoma, characterized by follicular conjunctivitis), then long-term: ii) scarring (chronic trachoma, characterized by conjunctival fibrosis, corneal opacification and eyelid malposition). Scarring trachoma is driven by the number and severity of reinfections. The immune system plays a pivotal role in trachoma including exacerbation of the disease. Hence the immune system may also be key to developing a trachoma vaccine. Therefore, we characterized clinical and local immune response kinetics in a non-human primate model of acute conjunctival Ct infection and disease. The conjunctiva of non-human primate (NHP, Cynomolgus monkeys-Macaca fascicularis-) were inoculated with Ct (B/Tunis-864 strain, B serovar). Clinical ocular monitoring was performed using a standardized photographic grading system, and local immune responses were assessed using multi-parameter flow cytometry of conjunctival cells, tear fluid cytokines, immunoglobulins, and Ct quantification. Clinical findings were similar to those observed during acute trachoma in humans, with the development of typical follicular conjunctivitis from the 4th week post-exposure to the 11th week. Immunologic analysis indicated an early phase influx of T cells in the conjunctiva and elevated interleukins 4, 8, and 5, followed by a late phase monocytic influx accompanied with a decrease in other immune cells, and tear fluid cytokines returning to initial levels. Our NHP model accurately reproduces the clinical signs of acute trachoma, allowing for an accurate assessment of the local immune responses in infected eyes. A progressive immune response occurred for weeks after exposure to Ct, which subsided into a persistent innate immune response. An understanding of these local responses is the first step towards using the model to assess new vaccine and therapeutic strategies for disease prevention.

Addressing Challenges in Chlamydia trachomatis Detection: A Comparative Review of Diagnostic Methods.

Chlamydial infections are one of the most common sexually transmitted bacterial infections worldwide, which is related to serious consequences for the mental, sexual, and reproductive health of women and men. The infection is commonly asymptomatic; consequently, screening programs for infection control have been introduced in some countries. The detection methods of Chlamydia trachomatis infections have evolved since the establishment of the first gold-standard detection method in the 1970s, the culture assay. Over the decades, many efforts were made to find methods with a higher sensitivity, until the 1990s, when, as a result of advances in molecular biology, nucleic acid amplification tests came into use with more sensitivity, and, currently, there are several available with which to detect infection. Therefore, herein, we will review the main methods used for CT detection and the differences between them, in terms of targets, infections that can be detected, sensitivity, and specificity. We will focus on some of the FDA-approved CT detection tests and highlight the major advantages and superiority of using molecular biology techniques. In addition, we will examine the larger challenges and limitations of the methods currently in use and discuss how they might be surpassed. Moreover, in this review, we will describe the next step to carry out after testing positive for CT infection.

Structural Assessment of Chlamydia trachomatis Major Outer Membrane Protein (MOMP)-Derived Vaccine Antigens and Immunological Profiling in Mice with Different Genetic Backgrounds.

Chlamydia trachomatis (Ct) is the most common cause of bacterial sexually transmitted infections (STIs) worldwide. Ct infections are often asymptomatic in women, leading to severe reproductive tract sequelae. Development of a vaccine against Chlamydia is crucial. The Chlamydia major outer membrane protein (MOMP) is a prime vaccine antigen candidate, and it can elicit both neutralizing antibodies and protective CD4+ T cell responses. We have previously designed chimeric antigens composed of immunogenic variable regions (VDs) and conserved regions (CDs) of MOMP from Chlamydia muridarum (Cm) expressed into a carrier protein (PorB), and we have shown that these were protective in a mouse model of Cm respiratory infection. Here, we generated corresponding constructs based on MOMP from Ct serovar F. Preliminary structure analysis of the three antigens, PorB/VD1-3, PorB/VD1-4 and PorB/VD1-2-4, showed that they retained structure features consistent with those of PorB. The antigens induced robust humoral and cellular responses in mice with different genetic backgrounds. The antibodies were cross-reactive against Ct, but only anti-PorB/VD1-4 and anti-PorB/VD1-2-4 IgG antibodies were neutralizing, likely due to the antigen specificity. The cellular responses included proliferation in vitro and production of IFN-γ by splenocytes following Ct re-stimulation. Our results support further investigation of the PorB/VD antigens as potential protective candidates for a Chlamydia subunit vaccine.

Field- and laboratory-based studies on correlates of Chlamydia trachomatis transmission by Musca sorbens: Determinants of fly-eye contact and investigations into fly carriage of elementary bodies.

Musca sorbens (Diptera: Muscidae) flies are thought to be vectors of the blinding eye disease trachoma, carrying the bacterium Chlamydia trachomatis (Ct) between the eyes of individuals. While their role as vectors has been convincingly demonstrated via randomised controlled trials in The Gambia, studies of fly-borne trachoma transmission remain scant and as such our understanding of their ability to transmit Ct remains poor. We examined fly-eye contact and caught eye-seeking flies from 494 individuals (79% aged ≤9 years) in Oromia, Ethiopia. Ct-carrying flies (harbouring Ct DNA) were found to cluster spatially in and nearby to households in which at least one resident had Ct infection. Fly-eye contact was positively associated with the presence of trachoma (disease), lower human body weight and increased human body temperature. Studies of laboratory-reared M. sorbens indicated that Ct is found both externally and internally following feeds on Ct culture, with scanning electron microscopy revealing how Ct bodies can cling to fly hairs (setae). Testing for Ct on field-caught M. sorbens found fly 'bodies' (thorax, wings and abdomen) to consistently test positive for Ct while legs and heads were infrequently Ct-positive. These studies strongly support the role of M. sorbens as vectors of trachoma and highlight the need for improved understanding of fly-borne trachoma transmission dynamics and vector competence.

Acceptability and feasibility of tests for infection, serological testing, and photography to define need for interventions against trachoma.

Trachoma causes blindness due to repeated conjunctival infection by Chlamydia trachomatis (Ct). Transmission intensity is estimated, for programmatic decision-making, by prevalence of the clinical sign trachomatous inflammation-follicular (TF) in children aged 1-9 years. Research into complementary indicators to field-graded TF includes work on conjunctival photography, tests for ocular Ct infection, and serology. The perceived acceptability and feasibility of these indicators among a variety of stakeholders is unknown. Focus group discussions (FGDs) with community members and in-depth interviews (IDIs) with public health practitioners in Tanzania were conducted. FGDs explored themes including participants' experience with, and thoughts about, different diagnostic approaches. The framework method for content analysis was used. IDIs yielded lists of perceived strengths of, and barriers to, implementation for programmatic use of each indicator. These were used to form an online quantitative survey on complementary indicators distributed to global stakeholders via meetings, mailing lists, and social media posts. Sixteen FGDs and 11 IDIs were conducted in October-November 2022. In general, all proposed sample methods were deemed acceptable by community members. Common themes included not wanting undue discomfort and a preference for tests perceived as accurate. Health workers noted the importance of community education for some sample types. The online survey was conducted in April-May 2023 with 98 starting the questionnaire and 81 completing it. Regarding barriers to implementing diagnostics, the highest agreement items related to feasibility, rather than acceptability. No evidence of significant differences was found in responses pertaining to community acceptability based on participant characteristics. All of the indicators included were generally deemed acceptable by all stakeholders in Tanzania, although community education around the benefits and risks of different sample types, as well as addressing issues around feasibility, will be key to successful, sustainable integration of these indicators into trachoma programs.

Prevalence of Chlamydia trachomatis and Neisseria gonorrhoeae infections among sexual assault victims referred to three French clinical forensic units

BackgroundChlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) infections are the most common bacterial sexually transmitted infections (STIs) worldwide. These STIs are frequently asymptomatic, which often delays diagnosis and treatment with the risk of serious long-term complications. Current French recommendations call for targeted screening of populations considered to be at risk, including victims of sexual assault. However, no recent data on the prevalence of these STIs in this population are available in France. The aim of this study was therefore to determine the prevalence of CT/NG infections among victims of sexual assault attending three Clinical Forensic Units (CFUs). MethodsWe retrospectively reviewed the forensic records of patients aged over 12 years reporting a sexual assault and referred between January 1, 2020 and December 31, 2021 to the CFU of Montpellier, Angers or Saint-Denis de La Réunion. Patients who had been screened for CT and NG infections were included. Results341 alleged victims of sexual assault (324 women, 17 men, median age = 23 years) were screened for CT/NG STIs during the inclusion period (Montpellier, n=196; Angers, n=63; Saint-Denis, n=82). The median time between the sexual assault and the examination was 1 day. CT and NG were detected in 28 patients (8.2 %) and 8 patients (2.3 %) respectively, with no men tested positive. Positive results concerned genital samples, except for two CT-positive anorectal samples and one NG-positive oropharyngeal sample. Two patients (0.6 %) were co-infected with CT/NG. The overall prevalence of CT/NG STIs was 10.0 % and was higher in the 18–24 age group, reaching 13.2 % for CT. ConclusionsThis multicenter study confirms the high prevalence of CT/NG STIs in victims of sexual assault, and the vulnerability of the youngest age groups to these infections. Systematic screening for CT/NG STIs at the time of the forensic examination is the key to early diagnosis and effective treatment to prevent transmission and subsequent complications in these patients.

Unravelling Chlamydia trachomatis diversity in Amhara, Ethiopia: MLVA-ompA sequencing as a molecular typing tool for trachoma.

Trachoma is the leading infectious cause of blindness worldwide and is now largely confined to around 40 low- and middle-income countries. It is caused by Chlamydia trachomatis (Ct), a contagious intracellular bacterium. The World Health Organization recommends mass drug administration (MDA) with azithromycin for treatment and control of ocular Ct infections, alongside improving facial cleanliness and environmental conditions to reduce transmission. To understand the molecular epidemiology of trachoma, especially in the context of MDA and transmission dynamics, the identification of Ct genotypes could be useful. While many studies have used the Ct major outer membrane protein gene (ompA) for genotyping, it has limitations. Our study applies a typing system novel to trachoma, Multiple Loci Variable Number Tandem Repeat Analysis combined with ompA (MLVA-ompA). Ocular swabs were collected post-MDA from four trachoma-endemic zones in Ethiopia between 2011-2017. DNA from 300 children with high Ct polymerase chain reaction (PCR) loads was typed using MLVA-ompA, utilizing 3 variable number tandem repeat (VNTR) loci within the Ct genome. Results show that MLVA-ompA exhibited high discriminatory power (0.981) surpassing the recommended threshold for epidemiological studies. We identified 87 MLVA-ompA variants across 26 districts. No significant associations were found between variants and clinical signs or chlamydial load. Notably, overall Ct diversity significantly decreased after additional MDA rounds, with a higher proportion of serovar A post-MDA. Despite challenges in sequencing one VNTR locus (CT1299), MLVA-ompA demonstrated cost-effectiveness and efficiency relative to whole genome sequencing, providing valuable information for trachoma control programs on local epidemiology. The findings suggest the potential of MLVA-ompA as a reliable tool for typing ocular Ct and understanding transmission dynamics, aiding in the development of targeted interventions for trachoma control.

A TriAdj-Adjuvanted Chlamydia trachomatis CPAF Protein Vaccine Is Highly Immunogenic in Pigs.

Chlamydia trachomatis (Ct) infections are the most common sexually transmitted infection (STI). Despite effective antibiotics for Ct, undetected infections or delayed treatment can lead to infertility, ectopic pregnancies, and chronic pelvic pain. Besides humans, chlamydia poses similar health challenges in animals such as C. suis (Cs) in pigs. Based on the similarities between humans and pigs, as well as their chlamydia species, we use pigs as a large biomedical animal model for chlamydia research. In this study, we used the pig model to develop a vaccine candidate against Ct. The vaccine candidate consists of TriAdj-adjuvanted chlamydial-protease-like activity factor (CPAF) protein. We tested two weekly administration options-twice intranasal (IN) followed by twice intramuscular (IM) and twice IM followed by twice IN. We assessed the humoral immune response in both serum using CPAF-specific IgG (including antibody avidity determination) and also in cervical and rectal swabs using CPAF-specific IgG and IgA ELISAs. The systemic T-cell response was analyzed following in vitro CPAF restimulation via IFN-γ and IL-17 ELISpots, as well as intracellular cytokine staining flow cytometry. Our data demonstrate that while the IN/IM vaccination mainly led to non-significant systemic immune responses, the vaccine candidate is highly immunogenic if administered IM/IN. This vaccination strategy induced high serum anti-CPAF IgG levels with strong avidity, as well as high IgA and IgG levels in vaginal and rectal swabs and in uterine horn flushes. In addition, this vaccination strategy prompted a pronounced cellular immune response. Besides inducing IL-17 production, the vaccine candidate induced a strong IFN-γ response with CD4 T cells. In IM/IN-vaccinated pigs, these cells also significantly downregulated their CCR7 expression, a sign of differentiation into peripheral-tissue-homing effector/memory cells. Conclusively, this study demonstrates the strong immunogenicity of the IM/IN-administered TriAdj-adjuvanted Ct CPAF vaccine candidate. Future studies will test the vaccine efficacy of this promising Ct vaccine candidate. In addition, this project demonstrates the suitability of the Cs pre-exposed outbred pig model for Ct vaccine development. Thereby, we aim to open the bottleneck of large animal models to facilitate the progression of Ct vaccine candidates into clinical trials.

Prevalence of Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, and Mycoplasma genitalium and risk factors among pregnant women in Brazil: Results from the national molecular diagnosis implementation project.

Sexually transmitted infections (STIs) are a public health problem. The aim of the present study was to assess the prevalence and risk factors associated with at least one STI (Chlamydia trachomatis [CT], Neisseria gonorrhoeae [NG], Trichomonas vaginalis [TV], and Mycoplasma genitalium [MG]) in Brazil. A cross-sectional study was conducted using secondary data from the pilot implementation of the National Service for molecular diagnosis of CT, NG, TV, and MG in pregnancy. We obtained Ministry of Health surveillance data from the implementation project. Data encompassing pregnant women aged 15-49 years from public antenatal clinics in Brazil in 2022 were included. A total of 2728 data of pregnant women were analyzed. The prevalence of at least one infection was 21.0% (573), with the highest prevalence in the Southeast region (23.3%) and the lowest in the Center-West region (15.4%). The prevalence of CT was 9.9% (270), NG 0.6% (16), TV 6.7% (184), and MG 7.8% (212). Factors associated with any infection were from 15 to 24 years (AOR = 1.93; 95% CI: 1.58-2.35); reported family income up to US$400 (AOR = 1.79; 95% CI: 1.03-3.34); declared not living maritally with their partners (AOR = 1.90, 95% CI: 1.52-2.37) and had more than one sexual partner in their lifetime (AOR = 2.09, 95% CI: 1.55-2.86). This study showed a high prevalence of at least one STI among pregnant women in Brazil, particularly among younger women. It also provides up-to-date national data on CT, NG, TV, and MG infections in this population. These findings underscore the importance of enhancing access to STI screening for young pregnant women within the Brazilian public health system.

Prevalence, risk factors and genotyping of chlamydia trachomatis from endocervical specimens of infertile women at a tertiary care hospital, Vietnam.

To our knowledge, the prevalence, risk factors and distribution of C. trachomatis genotypes are rarely mentioned in Vietnam. This study aimed to find the prevalence, risk factors and distribution of C. trachomatis genotypes in infertile Vietnamese women. Endocervical swabs were collected from infertile women at the National Hospital of Obstetrics and Gynecology, Vietnam, between January 2020 and December 2021. All samples were analyzed for C. trachomatis presence by Cobas 4800 CT/NG Test. Sequencing methods of ompA gene were used to determine the C. trachomatis genotypes. An approximately 1200 bp ompA fragment was aligned with reference sequences from GenBank to identify the corresponding genotype. The prevalence of endocervical C. trachomatis infection was 15.6% of 761 participants. Factors independently associated with CT infection among infertile women, obtained by multivariate analysis, included abnormal vaginal discharge, cervicitis, lower abdominal pain, a history of ectopic pregnancy, having more than one sex partner, and age at first intercourse. Among the samples, genotype E (25.93%) was most frequently found, followed by genotypes D/Da (22.23%), F (13.58%), G/Ga (12.35%), J (12.35%), H (6.17%), K (3.70%), B/Ba (2.47%), and I/Ia (1.23%), respectively. Genotype F was related to types of infertility, and genotype H was associated with a history of miscarriage. The present study indicated a high prevalence of C. trachomatis in infertile Vietnamese women. The most common genotypes found in this population were E, D, and F. Our findings suggest that routine screening is necessary for early detection and performance of infection control methods.

Reducing Barriers for Expedited Partner Treatment in Adolescents and Young Adults: A Quality Improvement Initiative.

Adolescents and young adults (AYAs) face significant barriers to screening, testing, and treatment of sexually transmitted infections (STIs). Expedited partner therapy (EPT) streamlines partner treatment of STIs, but use among adolescents is low. We aimed to increase EPT offering and provision at 2 adolescent medicine clinics (AMCs) and the emergency department (ED) in an urban children's hospital. We addressed barriers at provider, pharmacy, and patient levels. We compared EPT offering and provision for chlamydia ( Chlamydia trachomatis [CT]) and trichomonas ( Trichomonas vaginalis [TV]) infection at baseline and across 2 intervention cycles. Baseline data were collected from July 2019 to March 2020 and our intervention time frame spanned from April 2020 to October 2021. Laboratory codes identified patients with CT or TV infections. Cycle 1 allowed providers to order EPT within a patient's chart. The second cycle targeted education and standardization for STI/EPT notification and counseling. During this cycle, notification of ED patients was centralized to the AMC nurses. A total of 747 CT and TV cases were identified. In the AMC, EPT offering increased from 77.3% to 87.7% ( P = 0.01). Expedited partner therapy provision increased from 32.3% to 69.9% ( P < 0.001). Expedited partner therapy offering for ED patients increased by 82.3%. Retesting rates remained consistent, with a significant drop in reinfection rates ( P = 0.003) within patients seen in the AMC. This quality improvement initiative successfully increased EPT offering and provision among the cases identified. Future cycles may include longer-term follow-up to confirm partner treatment and testing per guidelines.

MIS-Net: A deep learning-based multi-class segmentation model for CT images.

The accuracy of traditional CT image segmentation algorithms is hindered by issues such as low contrast and high noise in the images. While numerous scholars have introduced deep learning-based CT image segmentation algorithms, they still face challenges, particularly in achieving high edge accuracy and addressing pixel classification errors. To tackle these issues, this study proposes the MIS-Net (Medical Images Segment Net) model, a deep learning-based approach. The MIS-Net model incorporates multi-scale atrous convolution into the encoding and decoding structure with symmetry, enabling the comprehensive extraction of multi-scale features from CT images. This enhancement aims to improve the accuracy of lung and liver edge segmentation. In the evaluation using the COVID-19 CT Lung and Infection Segmentation dataset, the left and right lung segmentation results demonstrate that MIS-Net achieves a Dice Similarity Coefficient (DSC) of 97.61. Similarly, in the Liver Tumor Segmentation Challenge 2017 public dataset, the DSC of MIS-Net reaches 98.78.

Association of Chlamydia trachomatis burden with the vaginal microbiota, bacterial vaginosis, and metronidazole treatment.

Bacterial vaginosis (BV), a dysbiosis of the vaginal microbiota, is a common coinfection with Chlamydia trachomatis (Ct), and BV-associated bacteria (BVAB) and their products have been implicated in aiding Ct evade natural immunity. Here, we determined if a non-optimal vaginal microbiota was associated with a higher genital Ct burden and if metronidazole, a standard treatment for BV, would reduce Ct burden or aid in natural clearance of Ct infection. Cervicovaginal samples were collected from women at enrollment and, if testing positive for Ct infection, at a follow-up visit approximately one week later. Cervical Ct burden was assessed by inclusion forming units (IFU) and Ct genome copy number (GCN), and 16S rRNA gene sequencing was used to determine the composition of the vaginal microbiota. We observed a six-log spectrum of IFU and an eight-log spectrum of GCN in our study participants at their enrollment visit, but BV, as indicated by Amsel's criteria, Nugent scoring, or VALENCIA community state typing, did not predict infectious and total Ct burden, although IFU : GCN increased with Amsel and Nugent scores and in BV-like community state types. Ct burden was, however, associated with the abundance of bacterial species in the vaginal microbiota, negatively with Lactobacillus crispatus and positively with Prevotella bivia. Women diagnosed with BV were treated with metronidazole, and Ct burden was significantly reduced in those who resolved BV with treatment. A subset of women naturally cleared Ct infection in the interim, typified by low Ct burden at enrollment and resolution of BV. Abundance of many BVAB decreased, and Lactobacillus increased, in response to metronidazole treatment, but no changes in abundances of specific vaginal bacteria were unique to women who spontaneously cleared Ct infection.

Evaluation of three formulations based on Polymorphic membrane protein D in mice infected with Chlamydia trachomatis.

The significant impact of Chlamydia trachomatis(Ct) infections worldwide highlights the need to develop a prophylactic vaccine that elicits effective immunity and protects the host from the immunopathological effects of Ct infection. The aim of this study was to evaluate a vaccine based on a fragment of the Polymorphic membrane protein D (FPmpD) of C. trachomatis as an immunogen using a heterologous DNA prime-protein boost strategy in female mice Three different formulations were evaluated as protein boost: free recombinant FPmpD (rFPmpD) or rFPmpD formulated with a liposomal adjuvant alternatively supplemented with CpG or a cationic gemini lipopeptide as immunostimulants. The three candidates induced an increase in the cervicovaginal and systemic titers of anti-rFPmpD antibodies in two strains of mice (BALB/c and C57BL/6), with no evidence of fertility alterations. The three formulations induced a rapid and robust humoral immune response upon the Ct challenge. However, the booster with free rFPmpD more efficiently reduced the shedding of infective Ct and prevented the development of immunopathology. The formulations containing adjuvant induced a strong inflammatory reaction in the uterine tissue. Hence, the prime-boost strategy with the adjuvant-free FPmpD vaccine formulation might constitute a promissory candidate to prevent C. trachomatis intravaginal infection.

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.

Mycoplasma Genitalium and Chlamydia Trachomatis Prevalence, Co-Infection and Relevant Factors in An Epidemiology Study (2016 - 2019) In Ho Chi Minh, Vietnam

Chlamydia trachomatis and Mycoplasma genitalium are two common types of sexually transmitted infections. However, currently in Vietnam, there is no report on the rate of patients infected by the two types of bacteria. In this study, there were 6194 patients visiting the STI clinic of the HCMC Hospital of Dermato-Venereology, Vietnam, from 2016 to 2019. The results show that the proportion of patients positive with CT and MG is independent on time. The infection rate is mainly at the age of 21 - 30 (53.4%). The CT infection rate in female and male is equal (17.3% vs 17.4%) while the rate of MG in female is lower (5.1% vs 7, 8%). The rate of patients co-infected with either CT or MG is 4.5%, 17% and 5.7% respectively, time independence. This study may give better understandings of the epidemiological characteristics of MG and CT in Vietnam.

P063 Host-mycobiome interactions during the resolution of inflammation in experimental colitis

Abstract Background Recent studies have documented the complexity of the intestinal fungal community (‘mycobiome’) in mice, and clinical and experimental observations have shown that the mycobiome influences both gut health and disease, e.g., IBD. In fact, prior studies have shown that CD patients, compared to healthy controls, harbor higher levels of intestinal Candida tropicalis (Ct), which is the major fungal species detected in the colons of colitic mice after dextran sodium sulfate (DSS) challenge. Moreover, proteins encoded by genes within IBD susceptibility loci, such as the pattern recognition receptor (PRR), NOD2, are known not only to recognize bacterial components, but also a fungal cell wall element, chitin. In fact, the role of PRRs in regulating immunity against intestinal fungi, and how fungi influence IBD remains poorly defined. Methods We challenged DSS colitic wildtype (WT) and Nod2-/- mice with Ct 2 days before DSS administration and subsequently on day 0, 3 and 6. Bone marrow-derived macrophages (BMDMs) from untreated mice were administered chitin in vitro. Results Our data confirms previous studies that Ct challenge does not exacerbate colitis in DSS-treated C57BL/6 WT mice, however, Ct-infected Nod2-/- mice possess a higher fungal burden and exhibit worse colitis symptoms, such as weight loss, decreased stool consistency, and presence of blood in stools, vs. Ct-infected WT mice, indicating an essential and protective role for NOD2 during colitis recovery after Ct challenge. Our results also show that Ct-infected Nod2-/- mice display a marked reduction in colonic Il22 and Il17, which are cytokines previously reported to be important in maintaining epithelial barrier integrity during DSS colitis. These data were confirmed in colons of Ct infected DSS challenged, ileitis prone SAMP1/YitFc (SAMP) mice NOD2 deficient. Moreover, our in vitro data show, a decrease in Il1ß and Il23 in BMDM from SAMP Nod2-/- mice compared to WT after 2h of exposure to chitin. IL-17+ innate lymphoid cells (ILCs) are also known to control fungal burden during opportunistic fungal infections, and interestingly, our findings indicate that Ct infection of Nod2-/- vs. WT mice results in a decreased frequency of mesenteric lymph node–derived type 3 ILCs (ILC3s), suggesting that delay in fungal clearance and recovery in Nod2-/-mice may be due to the inability to mount protective type 3 immune responses. Conclusion Taken together, the data collected suggests that NOD2 is essential to maintain gut mycobiome homeostasis and drives protective innate immune responses, via a macrophage-mediated ILC3 recruitment and IL-17 mechanism, by preventing the overgrowth of opportunistic fungi that may contribute to chronic intestinal inflammation, such as that observed in CD.