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To overcome shortcomings in discriminating Chlamydia pecorum strains infecting the koala (Phascolarctos cinereus) at the local level, we developed a novel genotyping scheme for this pathogen to inform koala management at a fine-scale subpopulation level. We applied this scheme to two geographically distinct koala populations in New South Wales, Australia: the Liverpool Plains and the Southern Highlands to South-west Sydney (SHSWS). Our method provides greater resolution than traditional multi-locus sequence typing, and can be used to monitor strain emergence, movement, and divergence across a range of fragmented habitats. Within the Liverpool Plains population, suspected recent introduction of a novel strain was confirmed by an absence of genetic diversity at the earliest sampling events and limited diversity at recent sampling events. Across the partially fragmented agricultural landscape of the Liverpool Plains, diversity within a widespread sequence type suggests that this degree of fragmentation may hinder but not prevent spread. In the SHSWS population, our results suggest movement of a strain from the south, where diverse strains exist, into a previously Chlamydia-free area in the north, indicating the risk of expansion towards an adjacent Chlamydia-negative koala population in South-west Sydney. In the south of the SHSWS where koala subpopulations appear segregated, we found evidence of divergent strain evolution. Our tool can be used to infer the risks of strain introduction across fragmented habitats in population management, particularly through practices such as wildlife corridor constructions and translocations., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Chlamydiosis, an infection caused by several Chlamydia species, has been reported in Nile, saltwater, and Siamese crocodiles. Despite its widespread reports in various countries, including Thailand, genetic information on Chlamydia species remains limited. This study presents a whole-genome-based characterization of Siamese crocodile-isolated Chlamydia. The results showed that Siamese crocodile Chlamydia contained a single circular chromosome with a size of 1.22-1.23 Mbp and a plasmid with a size of 7.7-8.0 kbp. A plasmid containing eight coding sequences (CDSs) was grouped in a β lineage. A chromosome sequence had approximately 1,018-1,031 CDSs. Chlamydial factors involving virulence were documented in terms of the presence of cytotoxins and several virulence factors in the chromosomes of Siamese crocodile Chlamydia. The analysis of antimicrobial resistance genes in the Chlamydia genome revealed that the most common resistance genes were associated with aminoglycosides, fluoroquinolones, macrolides, tetracyclines, and cephalosporins, with loose matching (identities between 21.12 % and 74.65 %). Phylogenetic analyses, encompassing the assessments of both whole proteome and nine taxonomic markers, revealed that Siamese crocodile Chlamydia was separated into three lineages (lineages I-III) with high bootstrapping statistic support. Interestingly, isolate 12-01 differed genetically from the others, suggesting that it is a new member of Chlamydia. The study findings indicate that Siamese crocodiles are susceptible hosts to Chlamydia, involving more than one species. This study is the first employing the highest number of whole-genome data on Siamese crocodile Chlamydia and provides better insights into pathogen genetics., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Chlamydia pecorum is a widespread veterinary chlamydial species causing endemic infections in livestock, such as ruminants and pigs, globally. However, there is limited contemporary knowledge on infecting strain diversity in various hosts. This study aimed to evaluate the genetic diversity of C. pecorum strains infecting Swiss livestock through C. pecorum genotyping and phylogenetic analyses in comparison to the global population, while also assessing chlamydial strains for plasmid carriage. A total of 263 C. pecorum positive samples from clinically healthy ruminant and pig herds (Bovines = 216, sheep = 25, pigs = 14) as well as placentae from eight C. pecorum positive ruminant abortion cases from other Swiss herds were investigated. The ompA and Multi-Locus sequence typing revealed novel C. pecorum genotypes, and bovine strains exhibited considerable genetic diversity, contrasting with lower diversity in sheep and pig strains. C. pecorum plasmid was detected in 100.0% of sheep (41/41) and pig (255/255) samples, and in 69.4% of bovine samples (150/216). In contrast, no plasmid was detected in the eight C. pecorum-positive ruminant abortion cases either representing plasmid-less strains or possibly escaping PCR detection due to autolysis of the placenta. This study supports the genetic diversity of C. pecorum strains, particularly in bovines, and identifies novel sequence types in Swiss livestock., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Nicole Borel reports financial support was provided by University of Zurich Vetsuisse Faculty. Nicole Borel reports a relationship with University of Zurich Vetsuisse Faculty that includes: funding grants. None If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Chlamydiaceae are a family of obligate intracellular bacterial pathogens that affect both humans and animals. Recently, a new species named Chlamydia (C.) buteonis was isolated from hawks. In this study, we aimed to investigate the prevalence of Chlamydiaceae in 60 falcons that underwent a routine health check at a specialized clinic in Dubai, United Arab Emirates. Using real-time PCR, we analyzed cloacal and tracheal swabs from these birds and found that 39 of them tested positive for Chlamydiaceae. Subsequent real-time PCR assays specific for C. psittaci, C. abortus, C. avium, and C. gallinacea yielded negative results, while testing positive for C. buteonis. Analysis of ompA and MLST sequences indicated a highly conserved group of strains within this set of samples, but with sequences distinct from the C. buteonis RSHA reference strains and other C. buteonis strains isolated from hawks in the United States. Two strains were further isolated by cell culture and sequenced using whole-genome sequencing, confirming the clustering of these falcon strains within the C. buteonis species, but in a separate clade from the previously identified hawk strains. We also developed a SNP-based PCR-HRM assay to distinguish between these different genotypes. Overall, our findings suggest a high prevalence of C. buteonis in falcons in Dubai and highlight the importance of monitoring this pathogen in birds of prey., Competing Interests: Declaration of Competing Interest None of the authors have any financial or personal relationships with any individuals or organizations that could inappropriately influence or bias this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Chlamydia remains the most notified bacterial sexually transmissible infection in Australia with guidelines recommending testing for re-infection at 3months post treatment. This paper aimed to determine chlamydia retesting and repeat positivity rates within 2-4months among young women in Australia, and to evaluate what factors increase or decrease the likelihood of retesting., Methods: Chlamydia retesting rates among 16-29-year-old women were analysed from Australian Collaboration for Coordinated Enhanced Sentinel Surveillance of sexually transmissible infection and bloodborne virus (ACCESS) sentinel surveillance data (n =62 sites). Among women with at least one positive test between 1 January 2018 and 31 August 2022, retesting counts and proportions within 2-4months were calculated. Logistic regression was performed to assess factors associated with retesting within 2-4months., Results: Among 8758 women who were positive before 31 August 2022 to allow time for follow up, 1423 (16.2%) were retested within 2-4months, of whom 179 (12.6%) tested positive. The odds of retesting within 2-4months were 25% lower if tested in a coronavirus disease 2019 (COVID-9) pandemic year (2020-2022) (aOR=0.75; 95% CI 0.59-0.95). Among 9140 women with a positive test before 30 November 2022, 397 (4.3%) were retested too early (within 7days to 1month) and 81 (20.4%) of those were positive., Conclusions: Chlamydia retesting rates remain low with around a sixth of women retested within 2-4months in line with guidelines. Re-infection is common with around one in eight retesting positive. An increase in retesting is required to reduce the risk of reproductive complications and onward transmission.

Chlamydia (C.) suis, a zoonotic intracellular bacterium, is described as a causative agent for conjunctivitis, particularly in nursery and fattening pigs. Chlamydiaceae are claimed to survive drying and to persist in dust. The objective of this study was to evaluate the viability of Chlamydia in dust sampled in a fattening pig farm with a high appearance of chlamydial-induced conjunctivitis. Dust was collected and stored at room temperature. To evaluate bacterial load and survival over time, quantitative PCR (Chlamydiaceae, C. suis) and isolation in cell culture were performed every week for up to 16 weeks. While qPCR results remained highly positive with consistent bacterial loads between 10 3 and 10 4 copy numbers/100 μL eluate over a period of 16 weeks and even after 40 weeks, it was not possible to isolate Chlamydia except for the initial sample. These results show only short-term viability of C. suis in dust. This is an important information regarding reduction of chlamydial loads in pig farms and risk for pigs and people to get infected via dust., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Patient-delivered partner therapy (PDPT) involves providing a prescription or medication to a patient diagnosed with chlamydia to pass to their sexual partner/s. Barriers to PDPT include uncertainty about its integration into clinical practice and permissibility. In Victoria, Australia, the Department of Health provides clinical guidance for PDPT (updated in 2022). We explored health practitioner views on the usefulness of the updated guidance for providing PDPT. Methods: We conducted an online survey (12 December 2022 to 2 May 2023) of health practitioners who primarily work in Victoria and can prescribe to treat chlamydia. The survey displayed excerpts from the guidance, and asked closed and free-text questions about its ability to address barriers to PDPT. Quantitative data were descriptively analysed, complemented by conventional content analysis of qualitative data. Results: Of a total of 49 respondents (66.7% general practitioners), 74.5% were aware of PDPT, and 66.7% had previously offered PDPT. After viewing excerpts of the guidance, >80% agreed it could support them to identify patients eligible/ineligible for PDPT, and 66.7% indicated they would be comfortable to offer PDPT. The guidance was viewed as helpful to address some barriers, including complicated documentation (87.7%) and medico-legal concerns (66.7%). Qualitative data highlighted medico-legal concerns by a minority of respondents. Some raised concerns that the guidance recommended prescribing azithromycin, despite doxycycline being first-line chlamydia treatment. Conclusions: The guidance was largely viewed as supportive for PDPT decision-making. There is scope for further refinements and clarifications, and wider dissemination of the guidance. Patient-delivered partner therapy (PDPT) involves providing a prescription or medication to a patient with chlamydia to pass to their sexual partner/s, but clinicians have expressed uncertainty about its permissibility and integration into practice. We surveyed clinician perspectives on updated health authority guidance for PDPT; finding they largely viewed it as supportive for PDPT decision-making and addressed some practical barriers. Low awareness of the updated guidance, and medico-legal concerns, for some, highlight scope for further dissemination and clarification of PDPT permissibility. [ABSTRACT FROM AUTHOR]

Background: The general practice out-of-hours (GPOOH) service is under pressure to treat more patients in less time, while reducing referrals and minimising diagnostic errors. Point-of-care (POC) testing involves rapid clinical tests that can be used to generate results during the consultation, and has the potential to facilitate managing these competing demands safely. Aim: To describe current availability of POC tests in GPOOH in Scotland, and identify barriers, enablers, benefits, and drawbacks to its use. Design & setting: Cross-sectional mixed-methods study, which surveyed opinions of clinicians working in the GPOOH service in NHS Scotland. Method: An electronic questionnaire was developed, designed, piloted, and distributed to clinicians, which had closed questions and areas for free text. Results: In total, 142 responses were received. Urine dipstick testing (99.2%), pregnancy tests (98.5%), oxygen saturation (97.7%), and blood glucose testing (93.9%), were the only POC tests commonly available in GPOOH in NHS Scotland. There was strongest support for the provision of POC tests, particularly C-reactive protein (CRP; 79.4%), strep A (76.0%), and D-dimer (75.2%). Responders felt that POC tests would improve confidence (92.3%) and safety (89.8%) surrounding clinical decision making, improve patient satisfaction (80.6%), and reduce hospital and secondary care referrals (77.5%). Barriers to POC test use were availability of the test kits and machines (94.5%), training requirements on how to use the machine (71.1%) and interpret results (56.3%), and time to do the test (62.0%). Conclusion: Few POC tests are in regular use in GPOOH in Scotland. GPOOH clinicians are supportive of using POC testing. They identified a number of benefits to its use, with very few drawbacks. Increased provision of POC testing in GPOOH in NHS Scotland should be considered urgently. [ABSTRACT FROM AUTHOR]

Objectives: Chlamydia trachomatis (chlamydia) is one of the most reported bacterial sexually transmitted infections (STI) worldwide. Chlamydia can cause long term complications such as pelvic inflammatory disease (PID), ectopic pregnancy (EP) and tubal factor infertility (TFI). Changing testing strategies, for example reduced asymptomatic testing, influence chlamydia surveillance, highlighting the need for exploring alternative ways of monitoring chlamydia. We investigated the possibility of introducing routine surveillance of chlamydia related long term complications. Methods: A qualitative study including 15 in-depth interviews with a purposive sample of gynaecologists, general practitioners (GP), sexual health and emergency doctors was conducted in the Netherlands in 2021–2022. A semi-structured interview guide focused on experiences with diagnosis and registration of PID, EP and TFI and how a change in asymptomatic chlamydia testing strategy might influence this. Interviews were transcribed and analysed using a thematic approach. Results: Analysis showed that gynaecologists most frequently reported diagnosing PID, EP and TFI. Other professions rarely diagnose these complications, with emergency doctors only diagnosing EP. Most respondents reported unique registration codes for PID and EP, but the coding for TFI is more ambiguous. They reflected that diagnosis and registration of PID, EP and TFI are handled differently within their professions. Most respondents acknowledged registration in diagnostic codes as a useful surveillance tool. They expressed concerns in representativeness (e.g. differences in interpretation of diagnosis criteria) and data quality for surveillance. Conclusions: Patient files of gynaecologists are likely to be most complete for monitoring trends of diagnosed chlamydia related long term complications in the Netherlands. However, when establishing a chlamydia complication surveillance system, professionals should be engaged in further standardizing diagnosis and registration practices. This will improve the quality and interpretability of complication surveillance and facilitate comparison between countries. [ABSTRACT FROM AUTHOR]

Background: We investigated the presence of Chlamydia psittaci in poultry and the environment in live poultry wholesale markets in Changsha during 2021–2022 and conducted a phylogenetic analysis to understand its distribution in this market. Methods: In total, 483 samples were analyzed using real-time polymerase chain reaction and 17 C. psittaci-positive samples using high-throughput sequencing, BLAST similarity, and phylogenetic analysis. Results: Twenty-two out of 483 poultry and environmental samples were positive for C. psittaci (overall positivity rate: 4.55%) with no difference in positivity rates over 12 months. Chlamydia psittaci was detected at 11 sampling points (overall positivity rate: 27.5%), including chicken, duck, and pigeon/chicken/duck/goose shops, with pigeon shops having the highest positivity rate (46.67%). The highest positivity rates were found in sewage (12.5%), poultry fecal (7.43%), cage swab (6.59%), avian pharyngeal/cloacal swab (3.33%), and air (2.29%) samples. The ompA sequences were identified in two strains of C. psittaci, which were determined to bear genotype B using phylogenetic analysis. Thus, during monitoring, C. psittaci genotype B was detected in the poultry and environmental samples from the poultry wholesale market in Changsha. Conclusions: To address the potential zoonotic threat, C. psittaci monitoring programs in live poultry markets should be enhanced. [ABSTRACT FROM AUTHOR]

Men having sex with men (MSM) represent a key population, in which sexually transmitted rectal infections (STIs) caused by Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and high-risk HPV (HR-HPV) are very common and linked to significant morbidity. Investigating the anorectal microbiome associated with rectal STIs holds potential for deeper insights into the pathogenesis of these infections and the development of innovative control strategies. In this study, we explored the interplay at the rectal site between C. trachomatis, N. gonorrhoeae, HR-HPV infection, and the anorectal microbiome in a cohort of 92 MSM (47 infected by CT and/or NG vs 45 controls). Moreover, we assessed the presence of Torquetenovirus (TTV), a non-pathogenic endogenous virus, considered as a possible predictor of immune system activation. We found a high prevalence of HR-HPV rectal infections (61%), especially in subjects with a concurrent CT/NG rectal infection (70.2%) and in people living with HIV (84%). In addition, we observed that TTV was more prevalent in subjects with CT/NG rectal infections than in non-infected ones (70.2% vs 46.7%, respectively). The anorectal microbiome of patients infected by CT and/or NG exhibited a reduction in Escherichia, while the presence of TTV was significantly associated with higher levels of Bacteroides. We observed a positive correlation of HR-HPV types with Escherichia and Corynebacterium, and a negative correlation with the Firmicutes phylum, and with Prevotella, Oscillospira, Sutterella. Our findings shed light on some of the dynamics occurring within the rectal environment involving chlamydial/gonococcal infections, HPV, TTV, and the anorectal microbiome. These data could open new perspectives for the control and prevention of STIs in MSM. [ABSTRACT FROM AUTHOR]

The members of the Chlamydiaceae family are important pathogens that infect a wide range of vertebrate hosts, including humans. Among them, Chlamydia psittaci, historically considered as an avian agent, has recently been identified in livestock, primarily sheep and cattle, but also in horses, with the infection being linked to reproductive disorders, such as abortion, absorption of embryos, stillbirth, and the birth of weak foals. Much less is known about chlamydial infections in the Sardinian equine population. This study aimed to identify the chlamydial diversity in genital samples from asymptomatic Sardinian horses. However, some horses had a previous history of reproductive disorders, i.e., abortion and infertility. A total of 60 horses (39 mares and 21 stallions) were opportunistically recruited from 17 equine farms in central-northern Sardinia. Vaginal and uterine swabs from mares and urethral swabs and seminal fluid from stallions were sampled for the presence of chlamydial DNA. Samples from environments where the horses lived were also tested for the detection of Chlamydia spp. Eight vaginal swabs (8/39; 20%), two uterine swabs (2/27; 7%), two seminal fluid samples (2/20; 10%), and one urethral swab (1/21; 4.7%) were found to be positive for Chlamydia spp. by PCR analysis. In addition, results from environmental samples showed the presence of Chlamydia spp. in three environmental swabs (3/8; 37.5%) and five water samples (5/16; 31.2%). Sequencing results revealed that strains here identified were 99–100% similar to members belonging to the Chlamydiaceae family, including C. abortus, C. psittaci, and uncultured Chlamydia genotypes. ompA species-specific PCR performed on samples was found to be positive after 16S rRNA amplification gave positive results for C. psittaci. These results reveal the first presence of C. psittaci in the genital tract of horses and in the environment in Sardinia and indicate that this pathogen could be the prevailing cause of infertility and abortion in the tested equines. However, these findings need further proof and highlight the importance of adopting a 'One Health' approach to control the presence of this zoonotic bacteria in domestic animals in order to understand its impact on people exposed to the infection risk. [ABSTRACT FROM AUTHOR]

Copyright of Misan Journal of Academic Studies is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Non-gonococcal sexually transmitted infections (STIs) include chlamydia, syphilis, and chancroids. Chlamydia is the most common STI caused by Chlamydia trachomatis and is mainly transmitted through sexual intercourse or vertical transmission at birth. Although symptoms are mostly absent or mild, untreated chlamydial infections in females can lead to pelvic inflammatory disease, chronic pelvic pain, and infertility due to the narrowing of fallopian tubes. Syphilis is caused by Treponema pallidum and is divided into phase I, phase II, latent syphilis, and phase III. The incidence of syphilis, including congenital syphilis, has significantly increased in the United States in recent years. The chronic status of this disease can significantly increase morbidity and potentially affect almost all body organs, which, in rare cases, can lead to death. Additionally, untreated maternal syphilis can lead to fetal death and fatal congenital infections in newborns. Chancroid is an STI caused by Haemophilus ducreyi, and its prevalence is gradually decreasing in Korea and worldwide. The symptoms include shallow genital ulcers with suppurative granulomatous inflammation and tender inguinal lymphadenopathy. Chancroids can be differentiated from syphilitic chancres based on their appearance. In contrast to painless chancres, chancroids are painful. Ureaplasma urealyticum, Ureaplasma parvum, and Mycoplasma hominis are considered symbiotic bacteria. Infections caused by these bacteria are usually not considered STIs and do not require treatment unless they are suspected of being associated with infertility. This article presents the 2023 Korean STI guidelines for non-gonococcal bacterial infections. [ABSTRACT FROM AUTHOR]

The clinical development of an effective Chlamydia vaccine requires in-depth understanding of how well protective pre-clinical immune signatures translate to humans. Here, we report a comparative immunological characterization of CTH522/CAF®01 in female mice and humans. We find a range of immune signatures that translate from mouse to human, including a Th1/Th17 cytokine profile and antibody functionality. We identify vaccine-induced T cell epitopes, conserved among Chlamydia serovars, and previously found in infected individuals. Using the mouse model, we show that the common immune signature protected against ascending infection in mice, and vaccine induced antibodies could delay bacterial ascension to the oviduct, as well as development of pathology, in a T cell depleted mouse model. Finally, we demonstrate long-lasting immunity and protection of mice one year after vaccination. Based on the results obtained in the present study, we propose to further investigate CTH522/CAF®01 in a phase IIb study. Authors present a comparative immunological characterisation of Chlamydia vaccine, CTH522/CAF®01, in mice and humans. Findings suggest the mouse to be a good predictor of human immunity to the Chlamydia vaccine CTH522/CAF®01, and long-lasting protection in the mouse further supports the development of this promising vaccine candidate. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Copyright of Al-Anbar Journal of Veterinary Sciences is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Chlamydia psittaci pneumonia (CPP) is a lung disease caused by the infection with the Chlamydia psittaci bacterium, which can lead to severe acute respiratory distress syndrome and systemic symptoms. This study explored the specific mechanisms underlying the impact of reactive oxygen species (ROS) on the Th17/Treg balance in CPP. The levels of ROS and the differentiation ratio of Th17/ Treg in the peripheral blood of healthy individuals and CPP patients were measured using ELISA and flow cytometry, respectively. The association between the ROS levels and Th17/Treg was assessed using Pearson correlation analysis. The ROS levels and the Th17/Treg ratio were measured in CD4+ T cells following H2O2 treatment and NLRP3 inhibition. The effects of H2O2 treatment and NLRP3 inhibition on the NLRP3/IL-1β/caspase-1 pathway were observed using immunoblotting. Compared to the healthy group, the CPP group exhibited increased levels of ROS in the peripheral blood, an elevated ratio of Th17 differentiation, and a decreased ratio of Treg differentiation. ROS levels were positively correlated with the Th17 cell proportion but negatively correlated with the Treg cell proportion. The ROS levels and NLRP3/IL-1β/caspase-1 expression were up-regulated in CD4+ T cells after H2O2 treat-ment. Furthermore, there was an increase in Th17 differentiation and a decrease in Treg differentiation. Conversely, the NLRP3/IL-1β/caspase-1 pathway inhibition reversed the effects of H2O2 treatment, with no significant change in the ROS levels. ROS regulates the Th17/Treg balance in CPP, possibly through the NLRP3/IL-1β/caspase-1 pathway. This study provides a new perspective on the development of immunotherapy for CPP. [ABSTRACT FROM AUTHOR]