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PubMed2005

Differences in growth characteristics and elementary body associated cytotoxicity between Chlamydia trachomatis oculogenital serovars D and H and Chlamydia muridarum.

AIM: In vitro growth and elementary body (EB) associated cytotoxicity of two Chlamydia trachomatis strains belonging to serovars D and H and C muridarum were compared to identify difference(s) that correlate with virulence variations between these strains in the mouse model of human female genital tract infection, and phenotypic characteristics that could explain human epidemiological data on serovar prevalence and levels of shedding during serovar D and H infection. METHODS: Replication cycle kinetics, inclusion characteristics, and EB associated cytotoxicity were assessed in McCoy cell monolayers using culture, light microscopy, and lactate dehydrogenase release. RESULTS: Over 72 hours, more rapid production and release of inclusion forming units (ifu) allowed C muridarum to initiate two replication rounds, resulting in 4-8 times more ifu/input unit of infection than with serovars D and H. Although C muridarum EBs were significantly more cytotoxic to McCoy cell monolayers than serovar D at moderate and high multiplicity of infection ratios (MOI), serovar H EBs were significantly more cytotoxic than C muridarum, even at the lowest MOI tested. CONCLUSIONS: These phenotypic differences are consistent with the more invasive course and severe pathological outcome of infection in mice infected with C muridarum, providing an objective basis for questioning the appropriateness of C muridarum as a surrogate for the human biovar of C trachomatis in the murine model of female genital tract infection. The differences seen between the human strains could help explain human epidemiological data relating to differences in prevalence and level of shedding that occurs during infection with oculogenital serovars D and H.

Cell Cycle↗
PubMed1996

Differential interaction with endocytic and exocytic pathways distinguish parasitophorous vacuoles of Coxiella burnetii and Chlamydia trachomatis.

Coxiella burnetii and Chlamydia trachomatis are bacterial obligate intracellular parasites that occupy distinct vacuolar niches within eucaryotic host cells. We have employed immunofluorescence, cytochemistry, fluorescent vital stains, and fluid-phase markers in conjunction with electron, confocal, and conventional microscopy to characterize the vacuolar environments of these pathogens. The acidic nature of the C. burnetii-containing vacuole was confirmed by its acquisition of the acidotropic base acridine orange (AO). The presence of the vacuolar-type (H+) ATPase (V-ATPase) within the Coxiella vacuolar membrane was demonstrated by indirect immunofluorescence, and growth of C. burnetii was inhibited by bafilomycin A1 (Baf A), a specific inhibitor of the V-ATPase. In contrast, AO did not accumulate in C. trachomatis inclusions nor was the V-ATPase found in the inclusion membrane. Moreover, chlamydial growth was not inhibited by Baf A or the lysosomotropic amines methylamine, ammonium chloride, and chloroquine. Vacuoles harboring C. burnetii incorporated the fluorescent fluid- phase markers, fluorescein isothiocyanate-dextran (FITC-dex) and Lucifer yellow (LY), indicating trafficking between that vacuole and the endocytic pathway. Neither FITC-dex nor LY was sequestered by chlamydial inclusions. The late endosomal-prelysosomal marker cation-independent mannose 6-phosphate receptor was not detectable in the vacuolar membranes encompassing either parasite. However, the lysosomal enzymes acid phosphatase and cathepsin D and the lysosomal glycoproteins LAMP-1 and LAMP-2 localized to the C. burnetii vacuole but not the chlamydial vacuole. Interaction of C. trachomatis inclusions with the Golgi-derived vesicles was demonstrated by the transport of sphingomyelin, endogenously synthesized from C6-NBD-ceramide, to the chlamydial inclusion and incorporation into the bacterial cell wall. Similar trafficking of C-NBD-ceramide was not evident in C. burnetii-infected cells. Collectively, the data indicate that C. trachomatis replicates within a nonacidified vacuole that is disconnected from endosome-lysosome trafficking but may receive lipid from exocytic vesicles derived from the trans-Golgi network. These observations are in sharp contrast to those for C. burnetii, which by all criteria resides in a typical phagolysosome.

Animals↗
PubMedDate not supplied

[Chlamydia trachomatis in women].

The results of the prospective study of chlamydia trachomatis infection in women are presented. The study comprised 288 women aged from 19 to 67 years with the completed clinical and anamnestic data and the following tests have been performed: indirect immunofluorescence test for detection of Chlamydia trachomatis antigens in endocervical smears (using monoclonal antibodies), ELISA test for detection of IgG antibodies against Chlamydia trachomatis in the sera and complement binding reaction for detection of antibodies against grouped Chlamydia antigen. Chlamydia trachomatis infection was found in 29.51% of cases equally distributed in all age groups. The incidence of Chlamydia positive findings was analysed according to clinical diagnosis, parity, relevant data from gynecologic anamnesis and the results of vaginal secretion and Papanicolau's stain test. In order to establish a reliable diagnosis of Chlamydia trachomatis infection two methods should be regularly used: one direct-for detection of a causative agent in patients' materials, and the other-indirect, for detection of specific antibodies in the serum.

Adult↗
PubMed1999

Screening for Chlamydia trachomatis in subfertile women.

Chlamydia trachomatis is the most common sexually transmitted disease in the UK and Europe. The majority of female infections are asymptomatic and recognized sequelae include pelvic inflammatory disease, infertility, and ectopic pregnancy. Women with chlamydial infection who undergo uterine instrumentation are recognized to be at risk of ascending infection. Most patients attending for infertility investigations and treatment will undergo some form of uterine instrumentation. Published data regarding the prevalence of chlamydial infection in the subfertile are few and conflicting. In this study, more than 400 consecutive women presenting for infertility investigation and treatment at a single regional fertility centre were screened for Chlamydia: Half were screened using enzyme immunoassay (EIA) and half by ligase chain reaction (LCR). Prevalence by diagnostic test was 0% with EIA and 1.9% with LCR. Overall, the low prevalence was at least partly explained by older age. Until more evidence comes from studies testing consecutive subfertile patients both with EIA and a DNA amplification method such as LCR, centres using EIA should consider using prophylactic antibiotics prior to uterine instrumentation.

Adult↗
PubMed2003

[Advances in the studies of Chlamydia trachomatis infection in males].

Chlamydia trachomatis(Ct) infection in reproductive tract is one of the most common sexually transmitted diseases at present. However, relatively fewer studies are made on Ct infection in men. The paper reviews the epidemiology of Ct infection in males, Ct infection and male diseases, Ct infection and male infertility, and the detection of Ct infection in men. It aims at providing a theoretical basis and a practical guide for the prevention and control of Ct infection in men.

Chlamydia Infections↗
PubMed1999

[DNA amplification in the diagnosis of urogenital Chlamydia trachomatis infection].

Sexually transmitted Chlamydia trachomatis infections are common and a major cause of pelvic inflammatory disease and its complications (infertility, ectopic pregnancy and chronic abdominal pain). No pathognomonic sign exists and the majority of infected individuals are asymptomatic. During the last eight years numerous evaluations of methods of detecting C trachomatis infections by use of DNA amplification have been published. The clinical sensitivity of the methods seem to be superior to antigen detection methods and cell culture. However, inhibitoric components may reduce the sensitivity of certain DNA tests and sample types. The increased sensitivity of DNA amplification tests allows the use of sample material which contain fewer organisms than the conventional swab sample, e.g. urine and vaginal samples. A strategy using home-obtained and mailed samples increases the efficacy of contact tracing and universal screening. Wider use of this strategy may reduce the risk of complications for the individual and reduce the prevalence of the infection in the society.

Chlamydia Infections↗
PubMed1993

Ultrastructural observations on the entry of Chlamydia trachomatis into human spermatozoa.

Chlamydia trachomatis infections are an important problem in human reproduction and family planning. In this study, the significance of chlamydial infection in male infertility and artificial insemination has been investigated. Electron microscope observations on male ejaculates have revealed the presence of the elementary and reticulate body forms of C.trachomatis in spermatozoa. Furthermore, the entry of the elementary body into the human spermatozoon head has been demonstrated. After the passage of the infectious elementary body into the nucleus, all stages of reticulate body formation in the head of the spermatozoon were detected. According to ultrastructural findings, C.trachomatis not only adhered to but also penetrated into the tail structure. Thus two different functional and morphological forms of C.trachomatis can infect and be transmitted by spermatozoa and may cause infertility.

Chlamydia Infections↗
PubMed1995

Chlamydia trachomatis. A trojan horse.

Chlamydia trachomatis is a prevalent and virulent pathogen in the genital tract of sexually active women. The sequelae are diverse and represent a significant source of morbidity. The Centers for Disease Control estimates 4 million new cases annually, making it the most prevalent sexually transmitted disease in the United States. Several risk factors are well-defined and the pathophysiology has become better understood, helping to improve the body of data concerning sequelae. Newer diagnostic methods, such as gene probes, ELISA, and PCR, are now available to aid in detection. Novel treatment regimens have been developed to improve eradication of the infection and compliance. There are still questions regarding this pathogen and its interaction with other lower genital tract pathogens. Improved detection, reporting and appropriate treatment can reduce the effect of Chlamydial infections on reproductive capacity.

Adolescent↗
PubMed2006

A small-molecule inhibitor of type III secretion inhibits different stages of the infectious cycle of Chlamydia trachomatis.

The intracellular pathogen Chlamydia trachomatis possesses a type III secretion (TTS) system believed to deliver a series of effector proteins into the inclusion membrane (Inc-proteins) as well as into the host cytosol with perceived consequences for the pathogenicity of this common venereal pathogen. Recently, small molecules were shown to block the TTS system of Yersinia pseudotuberculosis. Here, we show that one of these compounds, INP0400, inhibits intracellular replication and infectivity of C. trachomatis at micromolar concentrations resulting in small inclusion bodies frequently containing only one or a few reticulate bodies (RBs). INP0400, at high concentration, given at the time of infection, partially blocked entry of elementary bodies into host cells. Early treatment inhibited the localization of the mammalian protein 14-3-3beta to the inclusions, indicative of absence of the early induced TTS effector IncG from the inclusion membrane. Treatment with INP0400 during chlamydial mid-cycle prevented secretion of the TTS effector IncA and homotypic vesicular fusions mediated by this protein. INP0400 given during the late phase resulted in the detachment of RBs from the inclusion membrane concomitant with an inhibition of RB to elementary body conversion causing a marked decrease in infectivity.

14-3-3 Proteins↗
PubMed1992

Immune specificity of murine T-cell lines to the major outer membrane protein of Chlamydia trachomatis.

The antigenically variant Chlamydia trachomatis major outer membrane protein (MOMP) is a target of antibody-mediated neutralization in vitro, and it is an important protein for designing a subunit vaccine. Knowledge of MOMP T-cell determinants will be essential to elicit rapid and strong immune responses following an encounter with infectious organisms. C. trachomatis-specific T-cell lines were derived from MOMP-immunized BALB/c mice and selected with intact organisms. We used these short-term T-cell lines to identify determinants of MOMP that could be recognized by T cells following processing of the intact organism. T-cell line proliferation in response to overlapping MOMP peptides showed that only a peptide encompassing the third variable segment (VS3) elicited a strong proliferative response. We further mapped determinants within the VS3 peptide and found that a sequence-conserved portion of the VS3 peptide elicited T-cell proliferation of T-cell lines from BALB/c mice. Thus, unlike the response to several MOMP peptides with unselected T cells, development of short-term T-cell lines with intact organisms restricted the repertoire of antigens capable of being recognized by MOMP-specific T cells.

Amino Acid Sequence↗
PubMedDate not supplied

Effect of prior sexually transmitted disease on the isolation of Chlamydia trachomatis.

In developed nations, Chlamydia trachomatis is the most common sexually transmitted pathogen. To determine whether prior disease affects the probability of subsequent chlamydial infection, we took culture specimens from 2,546 men and 1,998 women attending a sexually transmitted diseases clinic. The men had nongonococcal urethritis and the women were contacts of men who had a positive chlamydial culture or nongonococcal urethritis. Significantly lower isolation rates for those with a history of sexually transmitted diseases were found for both men (29% vs. 38%; P less than 0.0001) and women (27% vs. 36%; P less than 0.0001). In addition, both men and women with previously documented chlamydial infections had a lower isolation rate at the index visit, if the previous infection occurred less than, as opposed to more than, six months earlier (men: 20% vs. 41%; P = 0.0006; women: 14% vs. 35%; P = 0.003). These relationships were found to be independent of age. However, the effect of partial immunity due to prior infection could not be distinguished from that of prior antibiotic therapy, and if such immunity does confer protection against reinfection, that protection appears to be both partial and of relatively short duration.

Chlamydia Infections↗
PubMed1980

Experimental infection of the marmoset genital tract with Chlamydia trachomatis.

A strain of Chlamydia trachomatis isolated in McCoy cells from the urethra of a patient suffering from non-gonococcal urethritis was inoculated into the vagina of 8 female marmosets. Chlamydiae were isolated repeatedly for 10-42 days from the lower genital tract of 7 of the marmosets. Six of the infected animals developed an acute inflammatory reaction in the genital tract and chlamydial inclusions in epithelial cells were seen in smears from 2 of them. In addition, each of 6 infected marmosets examined developed humoral antibodies to C. trachomatis. In contrast, 3 control animals inoculated intravaginally with chlamydia-free McCoy cells showed no evidence of chlamydial infection. Since the marmoset is small and easily bred in captivity, it should provide a useful model for studying the mechanisms of chlamydial pathogenicity.

Animals↗
PubMedDate not supplied

The prevalence of Chlamydia trachomatis infection in pregnant women.

PURPOSE: The aim of our study was to estimate the prevalence of Chlamydia trachomatis infection, the risk factors, the impact of the infection on the course of pregnancy and the condition of neonates born from pregnancies complicated by Chlamydia trachomatis infection. MATERIALS AND METHODS: 558 pregnant women aged 18-42 yrs, between the 4th and 40th week of pregnancy recruited from the Department of Obstetrics and Gynaecology, Medical Academy Lublin, and 10 men, partners of Chlamydia trachomatis infected patients were included in the study. All patients were examined using an immunoenzymatic method (MEIA). The ligase chain reaction (LCR) method was used only in cases of Chlamydia trachomatis detection with the use of MEIA method, in male partners of infected women and in patients with a cervical erosion and with a mucopurulent cervicitis. There were 64 women and 10 men who were examined using the LCR method. RESULTS: Positive results of MEIA test were found in 10 women (1.8% of studied population). Among men, the infection by Chlamydia trachomatis was present in 9 cases (90%). There were no infections with Chlamydia trachomatis in the group of neonates born from infected mothers. CONCLUSIONS: The prevalence of Chlamydia trachomatis infection was 1.8% in the studied group. The factors favourable for an infection are: young, unmarried patients, residents of towns or cities and changes in the cervix such as cervicitis or ectopy. In the cases of pathological pregnancy we should take into account Chlamydia trachomatis infections as a cause of abdominal pain or premature uterine contractions. The test towards Chlamydia trachomatis infection should be performed in pregnant patients to decrease the rate of pregnancy complications.

Adult↗
PubMed2005

Immunology of Chlamydia infection: implications for a Chlamydia trachomatis vaccine.

Sexually transmitted Chlamydia trachomatis infections are a serious public-health problem. With more than 90 million new cases occurring annually, C. trachomatis is the most common cause of bacterial sexually transmitted disease worldwide. Recent progress in elucidating the immunobiology of Chlamydia muridarum infection of mice has helped to guide the interpretation of immunological findings in studies of human C. trachomatis infection and has led to the development of a common model of immunity. In this review, we describe our current understanding of the immune response to infection with Chlamydia spp. and how this information is improving the prospects for development of a vaccine against infection with C. trachomatis.

Animals↗
PubMed1999

Study on vertical transmission of Chlamydia trachomatis using PCR and DNA sequencing.

OBJECTIVE: To investigate the vertical transmission rate of Chlamydia trachomatis (CT) in Chongqing, China. METHODS: Specimens taken from 278 women and from their 79 infants were examined by cell culture, polymerase chain reaction (PCR) and DNA sequence analysis. Chlamydia trachomatis was isolated in McCoy cell culture. CT DNA was extracted with a modified Nal method. After cloning, recombinant plasmids were used for sequence analysis with the dideoxy chain termination method. RESULTS: 10.8% (30/278) of the cervical cultures of pregnant women were positive for Chlamydia trachomatis, while the positive rate tested by PCR was 14.0% (39/278). The vertical transmission rate of Chlamydia trachomatis was 55.0% (11/20). The incidences of conjunctivitis and pneumonia in infants with Chlamydia trachomatis positive mothers were 27.3% and 18.2%, respectively. DNA sequences of Chlamydia trachomatis isolated from the cervix of a mother and the nasopharynx of her baby were identical. CONCLUSION: Chlamydia trachomatis infection is quite common in Chongqing, China. Our report is the first report of CT vertical transmission proved by DNA sequence analysis.

Adult↗
PubMed1997

Prevalence of Chlamydia trachomatis infection in a low-risk population in Hungary.

BACKGROUND AND OBJECTIVE: Chlamydia trachomatis is the leading cause of nongonococcal urethritis and cervicitis in women. Because of the recent increases in the numbers of new cases and severe consequences, there is an urgent demand for the introduction of sensitive and specific rapid diagnostic methods. GOAL: A multicenter examination involving seven centers was sponsored by the Hungarian Ministry of Health and Welfare in order to provide a survey of Chlamydia trachomatis in the gravid population. 6,161 women were tested between 1994 to 1995. STUDY DESIGN: The seven centers were selected with regard to different aspects, from developed and less developed areas in the capital, two large provincial towns, and various other provincial regions reflecting either an industrial or an agricultural background. The nucleic acid hybridization method (PACE 2 Gen-Probe, San Diego, CA) was introduced in this low-risk population for the examination of Chlamydia trachomatis. In one center, a further two methods, antigen detection by ELISA (SYVA, CA) and cultivation on the McCoy cell line (staining with SYVA FITC-labeled antichlamydia monoclonal antibody), were applied. RESULTS: International surveys and experience indicate that the proportion of the population threatened by Chlamydia trachomatis is above 10%. The overall average incidence of Chlamydia trachomatis cases in this low-risk gravid population was 5.74%. The data from the different centers ranged between 1.6% and 9.7%. The chlamydia-infected Hungarian gravid population is below the critical 10%, but there is one Hungarian county where the value is close to 10%. CONCLUSIONS: In this provincial, industrial area, the number of unmarried and divorced gravida in a low economic situation is disproportionately high. For this disadvantaged population, permanent Chlamydia trachomatis screening was suggested. In the other centers, screening of pregnant women for Chlamydia trachomatis and the treatment of positive cases and their partners were suggested for pathological gravida with preterm labor and preterm rupture of the membranes.

Adult↗
PubMed1988

Isolation of genital mycoplasmas and Chlamydia trachomatis in stillborn and neonatal autopsy material.

Chlamydia trachomatis and the genital mycoplasmas are significantly prevalent in sexually active women. How these organisms may affect the outcome of pregnancy and the neonate was the principal thrust of this investigation. Placenta, liver, and lung tissue were cultured from Mycoplasma hominis, Ureaplasma urealyticum, Chlamydia trachomatis, and aerobic as well as anaerobic bacteria in 432 stillborn and neonatal autopsies. Genital mycoplasmas were isolated from 36 cases (8.3%). Acute chorioamnionitis and funisitis were present significantly more often in cases with genital mycoplasma than in those without these organisms. Isolation of genital mycoplasmas was not associated with an increased incidence of intrauterine fetal death, villitis, hyaline membrane disease, congenital anomalies, or polymorphonuclear leukocytes in alveolar spaces. Chlamydia trachomatis was not found in any of the sites sampled.

Autopsy↗
PubMed1990

Postabortal pelvic sepsis in association with Chlamydia trachomatis.

Cervical swabs for Chlamydia trachomatis culture were taken from 527 women presenting for elective termination of pregnancy. Twenty-six patients (4.9%) harboured C. trachomatis; 21 (81%) of these were less than 25-years-old and 21 (81%) were nulliparas. Postoperative pelvic sepsis developed in 11.5% of chlamydia-positive women, in contrast to 3.6% of chlamydia-negative women. Consequently it is suggested that all patients, especially those younger than 25 years, presenting for termination of pregnancy or in whom an intrauterine device is to be inserted should be screened and have treatment commenced for C. trachomatis prior to the operative procedure.

Abortion, Induced↗