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chlamydia - Top 30 Publications

Physician Adherence to Sexually Transmitted Infection Screening Guidelines in an OB/GYN Teaching Clinic in Hawai'i.

Rates of chlamydia (CT) and gonorrhea (GC) have risen for the first time in the United States since 2006. Certain population groups are disproportionately affected by these sexually transmitted infections (STIs) as well as HIV. The Centers for Disease Control and Prevention (CDC) and professional societies have published screening guidelines for these STIs for women under the age of 25. We aimed to quantify physician adherence to GC/CT and HIV screening guidelines and to determine demographic factors associated with GC/CT and HIV screening recommendations among women 14-25 years old in Honolulu, Hawai'i. We conducted a retrospective chart review of all visits to an OB/GYN teaching clinic in 2014 to determine rates of STI screening recommendations and evaluate differences in screening recommendations by demographic factors such as patient age, race, insurance type, visit type, and visit number during the study period. Electronic medical records of 726 visits by 446 patients were reviewed. Among visits by patients with indications for screening, 71.0% and 21.6% received screening recommendations for GC/CT and HIV, respectively. Age group, race, and visit type were significantly associated with receiving screening recommendations. A lack of appropriate documentation regarding the assessment of risk factors for GC/CT and HIV screening was observed. Emphasis should be placed on more thorough ascertainment and documentation of patients' risk factors for STI acquisition to determine screening needs at each clinical visit based on professional guidelines, as substantial public health benefits may be gained through the identification and prompt treatment of GC/CT and HIV infections.

Erratum: Chlamydia trachomatis neither exerts deleterious effects on spermatozoa nor impairs male fertility.

A correction to this article has been published and is linked from the HTML version of this paper. The error has not been fixed in the paper.

B cell presentation of Chlamydia antigen selects out protective CD4γ13 T cells; implications for genital tract tissue resident memory lymphocyte clusters.

Surveillance and defense of the enormous mucosal interface with the nonsterile world is critical to protecting the host from a wide range of pathogens. Chlamydia trachomatis (Ct) is an intracellular bacterial pathogen that replicates almost exclusively in the epithelium of the reproductive tract. The fallopian tubes and vagina are poorly suited to surveillance and defense with limited immune infrastructure positioned near the epithelium. However, a dynamic process during clearing primary infections leaves behind new lymphoid clusters immediately beneath the epithelium. These memory lymphocyte clusters (MLC) harboring tissue resident memory T cells (Trm) are presumed to play an important role in protection from subsequent infections. Histologically, human Chlamydia MLC have prominent B cell populations. We investigated the status of genital tract B cells during C. muridarum infections, and the nature of T cells recovered from immune mice using immune B cells as antigen presenting cells (APC). These studies revealed a genital tract plasma B cell population and a novel genital tract CD4 T cell subset producing both IFN-γ and IL-13. A panel of CD4 T cell clones and microarray analysis showed that the molecular fingerprint of CD4γ13 T cells includes a Trm-like transcriptome. Adoptive transfer of a Chlamydia-specific CD4γ13 T cell clone completely prevented oviduct immunopathology without accelerating bacterial clearance. Existence of a CD4γ13 T cell subset provides a plausible explanation for the observation that human peripheral blood mononuclear cell (PBMC) Chlamydia-specific IFN-γ and IL-13 responses predict resistance to reinfection.

Attitudes to, and experience of, pooled sampling for sexually transmitted infection testing: a web-based survey of English sexual health services.

Chlamydia trachomatis and Neisseria gonorrhoeae testing guidance recommends extragenital screening with locally validated nucleic acid amplification tests, with anatomical sites tested separately. Evidence supports multi-patient combined aliquot pooled sampling (PS) for population screening; evidence for within-patient PS is sparse. Within-patient PS could be more cost-effective for triple-site testing, but requires distinct clinical pathways and consideration over loss of information to guide risk assessments and treatment. We explored PS attitudes and practices amongst clinicians in England. A cross-sectional web-based survey was distributed to clinical leads of sexual health services throughout England in February 2016. Fifty-two (52/216, 23%) services responded. One service reported current within-patient PS and two were awaiting implementation. Of the 49 services not pooling, five were considering implementation. Concerns raised included the inability to distinguish infection site(s) (36/52, 69%), absence of national guidance (34/52, 65%) and reduced assay performance (18/52, 34%). Only 8/52 (15%) considered the current level of evidence sufficient to support PS, with 40/52 (77%) requesting further validation studies and 39/52 (77%) national guidance. PS was rarely used by respondents to this survey, although the response rate was low. The clinical challenges presented by PS need to be addressed through further development of the evidence base.

Presence of Chlamydia trachomatis and Mycoplasma spp., but not Neisseria gonorrhoeae and Treponema pallidum, in women undergoing an infertility evaluation: high prevalence of tetracycline resistance gene tet(M).

Chlamydia trachomatis, Mycoplasma spp., Neisseria gonorrhoeae and Treponema pallidum are sexually transmitted pathogens that threaten reproductive health worldwide. In this study, vaginal swabs obtained from women (n = 133) that attended an infertility clinic in China were tested with qPCRs for C. trachomatis, Mycoplasma spp., N. gonorrhoeae, T. pallidum and tetracycline resistance genes. While none of vaginal swabs were positive for N. gonorrhoeae and T. pallidum, 18.8% (25/133) of the swabs were positive for Chlamydia spp. and 17.3% of the swabs (23/133) were positive for Mycoplasma species. All swabs tested were positive for tetracycline resistance gene tet(M) which is the most effective antibiotic for bacterial sexually transmitted infections. The qPCRs determined that the gene copy number per swab for tet(M) was 7.6 times as high as that of C. trachomatis 23S rRNA, and 14.7 times of Mycoplasma spp. 16S rRNA. In China, most hospitals do not detect C. trachomatis and Mycoplasma spp. in women with sexually transmitted infections and fertility problems. This study strongly suggests that C. trachomatis and Mycoplasma spp. should be routinely tested in women with sexually transmitted infections and infertility in China, and that antimicrobial resistance of these organisms should be monitored. Further studies are warranted to determine the prevalences in different regions and associated risk factors.

Phosphatidylserine decarboxylase CT699, lysophospholipid acyltransferase CT775, and acyl-ACP synthase CT776 provide membrane lipid diversity to Chlamydia trachomatis.

De novo lipid synthesis and scavenging of fatty acids (FA) are processes essential for the formation of the membrane of the human pathogen Chlamydia trachomatis (C.t.). Host FA are assimilated via esterification by the bacterial acyl-acyl carrier protein (ACP) synthase AasC but inhibitors of the host acyl-CoA synthetase enymes ACSL also impaired growth of C.t. in human cells. In E. coli, activity of AasC was sensitive to triacsin C and rosiglitazone G. The absence of a triacsin C-insensitive pathway and the increased inhibition by rosiglitazone G confirmed the sensitivity of the bacterial acyl-ACP synthase to these drugs in infected human cells. We found no evidence that the human ACSL enzymes are required for lipid formation by C.t. The broad substrate specificity of acyltransferase CT775 provides C.t. with the capacity to incorporate straight-chain and bacterial specific branched-chain fatty acids. CT775 accepts both acyl-ACP and acyl-CoA as acyl donors and, 1- or 2-acyl isomers of lysophosphoplipids as acyl acceptors. The enzyme responsible for remodeling of human phosphatidylserine to bacterial phosphatidylethanolamine was identified as CT699. These findings provide evidence that the pathogen has the ability to extend the lipid diversity of its membrane.

Routine screening for Chlamydia trachomatis and Neisseria gonorrhoeae in first trimester abortion.

Currently no recommendation exists to collect genital culture for Chlamydia trachomatis and Neisseria gonorrhoeae at diagnosis of spontaneous abortion. A retrospective cross sectional study was performed to identify first trimester abortions with concurrent genital culture collection in an emergency room setting. The results were compared to most current 2015 Center for Disease Control (CDC) statistics. Among women aged 15-24 the rate of C. trachomatis was increased to 20.0% and greater than CDC rate of 6.7% (RR 2.97, p<0.0001). No positive screens for C. trachomatis were found above age 30 and the study rate of N. gonorrhoeae was not significantly elevated. Younger women presenting for miscarriage have high prevalence of C. trachomatis in comparison to 2015 CDC statistics. Routine genital culture could be recommended at diagnosis of first trimester spontaneous abortion.

Waddlia chondrophila, a Chlamydia-related bacterium, has a negative impact on human spermatozoa.

What is the impact of Waddlia chondrophila, an emerging Chlamydia-related bacterium associated with miscarriage, on human spermatozoa?

Laboratory Testing of a Cohort of Commercially Insured Users of HIV Preexposure Prophylaxis in the United States, 2011-2015.

To ensure the health and safety of persons taking antiretroviral medication for HIV preexposure prophylaxis (PrEP), CDC guidelines recommend initial and follow-up laboratory testing. We assessed the rates of recommended testing using a commercial insurance claims database. Before taking PrEP, 45% of users were tested for HIV, 31% for creatinine, 55% for syphilis, 43% for chlamydia/gonorrhea, and 38% for hepatitis B. By 6 months after PrEP initiation, 38% were tested for HIV, 37% for creatinine, 49% for syphilis, and 39% for chlamydia/gonorrhea. Although laboratory testing was less frequent than recommended, testing rates increased over the study period.

Laboratory Screening for Children Entering Foster Care.

To determine the prevalence of medical illness detected by laboratory screening in children entering foster care in a single, urban county.

Prevalence of Chlamydia trachomatis-Specific Antibodies before and after Mass Drug Administration for Trachoma in Community-Wide Surveys of Four Communities in Nepal.

The target end date for the global elimination of trachoma as a public health problem is 2020. As countries begin the process for submitting their dossier for the validation of elimination of trachoma as a public health problem, strategies for post-validation surveillance must be considered. Seroprevalence of antibodies against antigens from the causative bacteria Chlamydia trachomatis (Ct) in young children has been shown to reflect trachomatous inflammation-follicular (TF) rates in both endemic and previously endemic settings. However, none of these studies has directly compared age seroprevalence in the same communities before and after mass drug administration (MDA) for trachoma. Here we report a marked shift in age seroprevalence curves in four villages in Kapilvastu District, Nepal, before and after MDA. Clinical examinations were performed and blood was taken before (N = 659) and 5 years after (N = 646) MDA. Rates of TF decreased from 17.6% in ≤ 9-year-olds before MDA (N = 52) to 0% in ≤ 9-year-olds (N = 73) after MDA. Positive antibody responses to Ct in the entire population decreased from 82.1% pre-MDA to 35.8% post-MDA, whereas those among ≤ 9-year-olds decreased from 59.6% to 4.1%. These data show that the postintervention decrease in TF was reflected in a drop in anti-Ct antibody responses, suggesting that antibody responses could be useful indicators for post-validation surveillance.

Repeat testing for chlamydia trachomatis, a "safe approach" to unsafe sex? a qualitative exploration among youth in Stockholm.

Chlamydia trachomatis testing is offered to youth in Sweden, through a network of Youth Health Clinics, free at the point of care, in an attempt to bring down the prevalence and incidence of the infection. Nevertheless, infections rates have continued to rise during the past two decades and re-testing rates among youth for Chlamydia trachomatis has been reported to be high in Stockholm County. A few literature reports suggest that testing for sexually transmitted infections and the test result itself can have an undesirable impact on the sexual behaviour for the individual, i.e. increase sexual risk-taking.

Can Chlamydia Serology Be Used to Help Inform a Potential Future Chlamydia Vaccination Strategy?

Young Men Who Have Sex with Men at High Risk for HIV, Bangkok MSM Cohort Study, Thailand 2006-2014.

High HIV incidence has been reported in young men who have sex with men (YMSM) in North America and Western Europe, but there are limited data from Southeast Asia suggesting MSM may be the driver of the HIV epidemic in this region. We described HIV incidence and risk factors among 494 YMSM enrolled in a cohort study in Bangkok, Thailand. The HIV incidence was 7.4 per 100 person-years. In multivariable analysis, reporting use of an erectile dysfunction drug in combination with club drugs, having receptive or both insertive and receptive anal intercourse with men, having hepatitis A infection, having rectal Chlamydia trachomatis, having hepatitis B infection prior to HIV seroconversion, and reporting not always using condoms with male steady partners were significantly associated with HIV incidence in YMSM. Reduction in new HIV infections in YMSM are critical to reach targets set by Thailand and the region.

Risk of Pelvic Inflammatory Disease in Relation to Chlamydia and Gonorrhea Testing, Repeat Testing, and Positivity: A Population-Based Cohort Study.

There is uncertainty around whether the risks of pelvic inflammatory disease (PID) differ following Chlamydia trachomatis (chlamydia) and Neisseria gonorrhoeae (gonorrhea) infection. We quantified the risk of PID associated with chlamydia and gonorrhea infection and subsequent repeat infections in a whole-population cohort.

Non-pathogenic colonization with Chlamydia in the gastrointestinal tract as oral vaccination for inducing transmucosal protection.

Chlamydia has been detected in the gastrointestinal tracts of humans and animals. We now report that gastrointestinal Chlamydia muridarum is able to induce robust transmucosal protection in mice. C. muridarum colonization in the gastrointestinal tract correlated with both a shortened course of C. muridarum genital infection and stronger protection against subsequent genital tract challenge infection. Mice pre-inoculated intragastrically with C. muridarum became highly resistant to subsequent C. muridarum infection in the genital tract, resulting in prevention of pathology in the upper genital tract. The transmucosal protection in the genital tract was rapidly induced, durable and dependent on MHC class II but not class I antigen presentation. Although deficiency in CD4+ T cells only partially reduced the transmucosal protection, depletion of CD4(+) T cells from B cell-deficient mice completely abolished the protection, suggesting a synergistic role of both CD4(+) T and B cells in the gastrointestinal C. muridarum-induced transmucosal immunity. However, the same protective immunity did not significantly affect C. muridarum colonization in the gastrointestinal tract. The long-lasting colonization with C. muridarum was restricted to the gastrointestinal tract and nonpathogenic to either gastrointestinal or extra-gastrointestinal tissues. Furthermore, the gastrointestinal C. muridarum did not alter gut microbiota or the development of gut mucosal resident memory T cells to a non-chlamydial infection. Thus, Chlamydia may be developed into a safe and orally deliverable replicating vaccine for inducing transmucosal protection.

Impact of capsaicin, an active component of chili pepper, on pathogenic chlamydial growth (Chlamydia trachomatis and Chlamydia pneumoniae) in immortal human epithelial HeLa cells.

Chlamydia trachomatis is the leading cause of sexually transmitted infections worldwide. Capsaicin, a component of chili pepper, which can stimulate actin remodeling via capsaicin receptor TRPV1 (transient receptor potential vanilloid 1) and anti-inflammatory effects via PPARγ (peroxisome proliferator-activated receptor-γ) and LXRα (liver X receptor α), is a potential candidate to control chlamydial growth in host cells. We examined whether capsaicin could inhibit C. trachomatis growth in immortal human epithelial HeLa cells. Inclusion forming unit and quantitative PCR assays showed that capsaicin significantly inhibited bacterial growth in cells in a dose-dependent manner, even in the presence of cycloheximide, a eukaryotic protein synthesis inhibitor. Confocal microscopic and transmission electron microscopic observations revealed an obvious decrease in bacterial numbers to inclusions bodies formed in the cells. Although capsaicin can stimulate the apoptosis of cells, no increase in cleaved PARP (poly (ADP-ribose) polymerase), an apoptotic indicator, was observed at a working concentration. All of the drugs tested (capsazepine, a TRPV1 antagonist; 5CPPSS-50, an LXRα inhibitor; and T0070907, a PPARγ inhibitor) had no effect on chlamydial inhibition in the presence of capsaicin. In addition, we also confirmed that capsaicin inhibited Chlamydia pneumoniae growth, indicating a phenomena not specific to C. trachomatis. Thus, we conclude that capsaicin can block chlamydial growth without the requirement of host cell protein synthesis, but by another, yet to be defined, mechanism.

Early screening for Chlamydia trachomatis in young women for primary prevention of pelvic inflammatory disease (i-Predict): study protocol for a randomised controlled trial.

Genital infection with Chlamydia trachomatis (Ct) is the most common bacterial sexually transmitted infection, especially among young women. Mostly asymptomatic, it can lead, if untreated, to pelvic inflammatory disease (PID), tubal factor infertility and ectopic pregnancy. Recent data suggest that Ct infections are not controlled in France and in Europe. The effectiveness of a systematic strategy for Ct screening in under-25 women remains controversial. The main objective of the i-Predict trial (Prevention of Diseases Induced by Chlamydia trachomatis) is to determine whether early screening and treatment of 18- to-24-year-old women for genital Ct infection reduces the incidence of PID over 24 months.

HIV and other STIs in male sex workers: Findings from a sexual health promotion intervention in Vietnam.

Male sex workers (MSWs) in Vietnam are at high risk for acquisition and transmission of human immunodeficiency virus (HIV) and other sexually transmitted infections (STIs), yet are extremely disengaged from the healthcare system. This contributes to large numbers of untreated or late-treated infections and increased secondary transmission. We enrolled 995 MSWs in Hanoi and Ho Chi Minh City (HCMC) in a Sexual Health Promotion intervention that included face-to-face delivery of seven content modules, a clinical examination and testing for HIV, syphilis, gonorrhea and Chlamydia. Onsite treatment was provided for STIs, and those who tested positive for HIV were referred to local treatment centers. While 64.6% of participants had never been to a health service and fewer than half (41.2%) had ever been tested for HIV, 67.1% returned for test results. This testing identified 109 (11.0%) participants who were HIV-positive and 312 (31.4%) who tested positive for at least one other STI. Substantive differences were seen in MSWs from different cities, with those from Hanoi more likely to have ever visited a health service (57.8% vs. 24.9%) and to have taken a prior HIV test (54.1% vs. 37.9%) than those in HCMC. Sexual health promotion is a promising approach to engaging MSWs in health services.

Diagnostic issues of lymphogranuloma venereum: A case series of 5 patients.

Lymphogranuloma venereum (LG) is a sexually transmitted infection (STI) caused by Chlamydia trachomatis L serovar.

An audit of a novel electronic messaging treatment service for Chlamydia trachomatis at a community pharmacy.

In 2016, NHS Lothian regional sexual and reproductive health services introduced an electronic pharmacy treatment voucher that could be sent to the mobile phones of patients with Chlamydia trachomatis and their sexual contacts. A retrospective audit of the electronic treatment voucher database was conducted for vouchers issued between April and December 2016. Five hundred and forty-nine vouchers were issued and 56% were redeemed at a pharmacy within one week of issue. This suggests that electronic vouchers are a popular and effective means of providing expedited treatment for uncomplicated C. trachomatis at a community pharmacy.

Effect of water, sanitation and hygiene interventions on active trachoma in North and South Wollo zones of Amhara Region, Ethiopia: A Quasi-experimental study.

Trachoma is chronic kerato conjunctivitis, which is caused by repeated infection with Chlamydia trachomatis bacterium. It is hyper endemic in many rural areas of Ethiopia. The objective of this study was to measure the effect of water, sanitation and hygiene interventions on active trachoma in selected woredas of North and South Wollo zones of Amhara Region, Ethiopia.

The 2017 Doyne Lecture: the orbit as a window to systemic disease.

A very large number of disorders affect the orbit, and many of these occur in the setting of systemic disease. This lecture covers selected aspects of orbital diseases with systemic associations in which the author has a particular clinical or research interest. Spontaneous orbital haemorrhage often occurs in the presence of bleeding diatheses. Thrombosis of orbital veins and ischaemic necrosis of orbital and ocular adnexal tissues occur with thrombophilic disorders, vasculitis, and certain bacterial and fungal infections. Non-infectious orbital inflammation commonly occurs with specific inflammatory diseases, including Graves' disease, IgG4-related disease, sarcoidosis, Sjögren's syndrome and granulomatosis with polyangiitis, all of which have systemic manifestations. IgG4-related ophthalmic disease is commoner than all these except Graves' orbitopathy. Some of these orbital inflammatory diseases are associated with an increased risk of B-cell lymphoma, usually marginal zone lymphoma of MALT type. Ocular adnexal lymphoma also has an association with infectious agents including Helicobacter pylori and Chlamydia psittaci. Orbital metastasis may be the first presentation of systemic malignancy. A number of orbital neoplasms occur in the setting of familial cancer syndromes, including Neurofibromatosis types 1 and 2. Study of the genetics and molecular biology of orbital diseases such as Graves' orbitopathy and idiopathic orbital inflammatory disease will yield useful information on their diagnosis and management.Eye advance online publication, 10 November 2017; doi:10.1038/eye.2017.224.

Chlamydia trachomatis versus common uropathogens as a cause of chronic bacterial prostatitis: Is there any difference? Results of a prospective parallel-cohort study.

The role of Chlamydia trachomatis (CT) infection in chronic bacterial prostatitis (CBP) is well known. What is unclear is whether there are any differences in the course or clinical outcome of the disease when the cause is CT or other uropathogens.

Dynamic Energy Dependency of Chlamydia trachomatis on Host Cell Metabolism during Different Stages of Intracellular Growth: Possible role of Sodium -based energetics in Chlamydial ATP generation.

Chlamydia trachomatis is an obligate intracellular human pathogen responsible for the most prevalent sexually-transmitted infection in the world. For decades C. trachomatis has been considered an "energy parasite" that relies entirely on the uptake of ATP from the host cell. The genomic data suggest that C. trachomatis respiratory chain could produce a sodium gradient that may sustain the energetic demands required for its rapid multiplication. However, this mechanism awaits experimental confirmation. Moreover, the relationship of Chlamydiae with the host cell, in particular its energy dependency, is not well understood. In this work we are showing that C. trachomatis has an active respiratory metabolism that seems to be coupled to the sodium-dependent synthesis of ATP. Moreover, our results show that the inhibition of mitochondrial ATP synthesis at an early stage decreases the rate of infection and the Chlamydial inclusion size. On the other hand, the inhibition of the Chlamydial respiratory chain at mid-stage of the infection cycle decreases the inclusion size, but has no effect on infection rate. Remarkably, the addition of monensin, a Na(+)/H(+) exchanger, completely halts the infection. Altogether our data indicate that Chlamydial development has a dynamic relationship with the mitochondrial metabolism of the host, in which the bacterium mostly depends on host ATP synthesis at an early stage, and at later stages it can sustain its own energy needs through the formation of a sodium gradient.

Chlamydia trachomatis and its interaction with the cellular retromer.

Chlamydia trachomatis is an important human pathogen. This obligate intracellular bacterium grows inside the eukaryotic cell in a membrane-bound compartment, the inclusion. Recent global approaches describe the interactions of C. trachomatis with its host cell and indicate the inclusion is an intracellular trafficking hub embedded into the cellular vesicular trafficking pathways recruiting subunits of the retromer protein complex of the host cell. Here we review these recent developments in deciphering Chlamydia-host cell interactions with emphasis on the role of the retromer complex.

Molecular prevalence of Chlamydia and Chlamydia-like bacteria in Tunisian domestic ruminant farms and their influencing risk factors.

Chlamydia and Chlamydia-like bacteria are well known to infect several organisms and may cause a wide range of diseases, particularly in ruminants. To gain insight into the prevalence and diversity of these intracellular bacteria, we applied a pan-Chlamydiales real-time PCR to 1,134 veterinary samples taken from 130 Tunisian ruminant herds. The true adjusted animal population-level prevalence was 12.9% in cattle, against 8.7% in sheep. In addition, the true adjusted herd-level prevalence of Chlamydiae was 80% in cattle and 25.5% in sheep. Chlamydiales from three family-level lineages were detected indicating a high biodiversity of Chlamydiales in ruminant herds. Our results showed that Parachlamydia acanthamoebae could be responsible for bovine and ovine chlamydiosis in central-eastern Tunisia. Multivariable logistic regression analysis at the animal population level indicated that strata and digestive disorders variables were the important risk factors of bovine and ovine chlamydiosis. However, origin and age variables were found to be associated with bovine and ovine chlamydiosis, respectively. At the herd level, risk factors for Chlamydia positivity were as follows: abortion and herd size for cattle against breeding system, cleaning frequency, quarantine, use of disinfectant and floor type for sheep. Paying attention to these risk factors will help improvement of control programs against this harmful zoonotic disease.

Serology reflects a decline in the prevalence of trachoma in two regions of The Gambia.

Trachoma is caused by Chlamydia trachomatis (Ct). It is targeted for global elimination as a public health problem. In 2014, a population-based cross-sectional study was performed in two previously trachoma-endemic areas of The Gambia. Participants of all ages from Lower River Region (LRR) (N = 1028) and Upper River Region (URR) (N = 840) underwent examination for trachoma and had blood collected for detection of antibodies against the Ct antigen Pgp3, by ELISA. Overall, 30 (1.6%) individuals had active trachoma; the prevalence in children aged 1-9 years was 3.4% (25/742) with no statistically significant difference in prevalence between the regions. There was a significant difference in overall seroprevalence by region: 26.2% in LRR and 17.1% in URR (p < 0.0001). In children 1-9 years old, seroprevalence was 4.4% in LRR and 3.9% in URR. Reversible catalytic models using information on age-specific seroprevalence demonstrated a decrease in the transmission of Ct infection in both regions, possibly reflecting the impact of improved access to water, health and sanitation as well as mass drug administration campaigns. Serological testing for antibodies to Ct antigens is potentially useful for trachoma programmes, but consideration should be given to the co-endemicity of sexually transmitted Ct infections.

Chlamydia trachomatis regulates growth and development in response to host cell fatty acid availability in the absence of lipid droplets.

Chlamydia trachomatis (Ct) is a Gram-negative obligate intracellular pathogen of humans that causes significant morbidity from sexually transmitted and ocular diseases globally. Ct acquires host fatty acids (FA) to meet the metabolic and growth requirements of the organism. Lipid droplets (LDs) are storehouses of FAs in host cells and have been proposed to be a source of FAs for the parasitophorous vacuole, termed inclusion, in which Ct replicates. Previously, cells devoid of LDs were shown to produce reduced infectious progeny at 24 hours post-infection (hpi). Here, while we also found reduced progeny at 24 hpi, there were significantly more progeny at 48 hpi in the absence of LDs compared to the control wild-type (WT) cells. These findings were confirmed using transmission electron microscopy where cells without LDs were shown to have significantly more metabolically active reticulate bodies at 24 hpi and significantly more infectious but metabolically inert elementary bodies at 48 hpi than WT cells. Furthermore, by measuring basal oxygen consumption rates (OCR) using extracellular flux analysis, Ct infected cells without LDs had higher OCRs at 24 hpi than cells with LDs, confirming ongoing metabolic activity in the absence of LDs. While the FA oleic acid (OA) is a major source of phospholipids for Ct and stimulates LD synthesis, treatment with OA, but not other FAs, enhanced growth and led to an increase in basal OCR in both LD depleted and WT cells, indicating that FA transport to the inclusion is not affected by the loss of LDs. Our results show that Ct regulates inclusion metabolic activity and growth in response to host FA availability in the absence of LDs.

Effects of Chlamydia trachomatis infection on sperm chromatin condensation and DNA integrity.

The present study was performed to investigate the relation of Chlamydia trachomatis infection to sperm chromatin/DNA integrity in a population of infertile men (male partner of infertile couples) from Iran. Blood, semen and first-void urine samples were obtained from 250 infertile men. Data were analysed with regard to the results of (i) serological analysis for specific antibodies to C. trachomatis in serum; (ii) the presence of C. trachomatis and DNA in first-void urine; and (iii) in the semen sample of the male partner, in addition to sperm analysis, four different tests (aniline blue, chromomycin A3, acridine orange and TUNEL) were used to detect sperm chromatin and DNA abnormalities. The main conclusions of the results were: (i) no evidence of C. trachomatis infection in semen samples was found; (ii) sperm DNA fragmentation and chromatin studies were not correlated with C. trachomatis diagnosis; (iii) the percentage of DNA fragmentation is positively correlated with the percentage of immotile sperm but negatively with semen volume, normal morphology; and (iv) in sperm chromatin evaluations, only the percentage of chromatin protamination was related to male age.