Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Chlamydia”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 451 records · Page 25Linked to original sources
PubMed1994

Detection of Chlamydia trachomatis in fallopian tube tissue in women with postinfectious tubal infertility.

OBJECTIVE: Biopsy tissues from women with postinfectious tubal infertility were studied for the presence of Chlamydia trachomatis. STUDY DESIGN: Tubal biopsy specimens from 25 women with postinfectious tubal infertility undergoing laparoscopy for repair of fallopian tubes were evaluated by culture, in situ hybridization. Immunocytochemistry, and transmission electron microscopy for the presence of Chlamydia trachomatis. Serum was also tested for Chlamydia trachomatis antibodies. RESULTS: Chlamydia trachomatis was detected in postinfectious tubal biopsy specimens in three of 25 patients by culture, 12 of 24 by in situ hybridization, 15 of 22 by immunoperoxidase stain, and two of 10 by transmission electron microscopy. Serum antibody against Chlamydia trachomatis was detected in 15 of 21 patients. CONCLUSION: Chlamydia trachomatis deoxyribonucleic acid or antigens were detected at a high percentage (19/24 women) in the biopsy tissues of the fimbrial and peritubal adhesions by in situ hybridization or immunoperoxidase stain, suggesting a persistent infection in these women even after antibiotic treatment.

Adult↗
PubMed1994

Detection of Chlamydia trachomatis deoxyribonucleic acid in monkey models (Macaca nemestrina) of salpingitis by in situ hybridization: implications for pathogenesis.

OBJECTIVE: Our purpose was to determine whether Chlamydia trachomatis persists in tubal tissues from monkey pocket models of chlamydial salpingitis and tubal infertility and to relate its presence to disease progression and histopathologic mechanisms. STUDY DESIGN: In situ hybridization was used to detect Chlamydia deoxyribonucleic acid in a monkey pocket model of salpingitis and in the direct tubal inoculation monkey model of tubal infertility. Results were correlated with culture and immunocytochemistry results and histopathologic characteristics. RESULTS: Chlamydia deoxyribonucleic acid was detected in the mucosa, submucosa, and deep tissues in the pocket model. In addition, it was present in peritubal adhesions from the direct inoculation model. Deoxyribonucleic acid was found at sites of inflammation and when culture and immunocytochemistry studies were negative. CONCLUSION: The presence of Chlamydia trachomatis deoxyribonucleic acid at sites of inflammation and tissue damage in monkey models of chlamydial salpingitis and tubal infertility suggests that Chlamydia persists and may be directly involved in the stimulation of the immune-mediated tissue destruction associated with Chlamydia trachomatis infections.

Animals↗
PubMed1996

The vaginal introitus: a novel site for Chlamydia trachomatis testing in women.

OBJECTIVE: We evaluated the vaginal introitus as a noninvasive sampling site for testing for Chlamydia trachomatis. STUDY DESIGN: Swabs from the vaginal introitus were obtained from 300 women attending a sexually transmitted diseases clinic and tested for the presence of Chlamydia trachomatis by polymerase chain reaction. Additionally, 200 of these women self-collected an additional introitus swab and submitted a urine sample for polymerase chain reaction testing. These samples were compared with polymerase chain reaction, culture, and enzyme immunoassay for Chlamydia trachomatis from endocervical samples and polymerase chain reaction and culture on urethral swabs. Patients were determined to be infected with Chlamydia trachomatis by a positive culture result from any site or a confirmed positive result by polymerase chain reaction with an alternate primer. RESULTS: The sensitivity of vaginal introitus swabs obtained by health care providers for the detection of urogenital Chlamydia trachomatis was 92% (95% confidence interval 83 to 100), greater than polymerase chain reaction, culture, or enzyme immunoassay of the cervix or urethra. The sensitivity by polymerase chain reaction of patient self-collected swabs was 81%. Sampling of the vaginal introitus, by both health care workers and the patient herself, performed as well as commonly used diagnostic tests that require vaginal speculum examination. The sensitivity of polymerase chain reaction testing of urine samples was 73%. CONCLUSION: The vaginal introitus represents a highly effective noninvasive specimen collection site for Chlamydia trachomatis testing by polymerase chain reaction. Self-collection of introitus specimens may revolutionize sexually transmitted disease testing by eliminating the need for a speculum examination by skilled health care personnel.

Chlamydia Infections↗
PubMed1991

The use of fluorescein-conjugated monoclonal antibodies, cell culture and transmission electron microscopy to detect Chlamydia psittaci and associated lesions in experimentally infected mice.

An immunofluorescence test based on a monoclonal antibody (mAb) was used to demonstrate chlamydiae in formalin-fixed and paraffin wax-embedded tissues from 10 adult mice experimentally infected by the oral route with Chlamydia psittaci isolated from the fetal membranes of an aborted ovine fetus. Samples of lung, jejunum and spleen were examined by bright-field microscopy, immunofluorescence and transmission electron microscopy, and were cultured for chlamydia in McCoy cells. These tissues were compared with those of two control mice. All infected mice had splenic hyperplasia and two had pneumonia. The lung appeared to be the target organ for C. psittaci administered by the oral route. Chlamydiae were identified in the lungs of five mice by immunofluorescence, bright-field and transmission electron microscopy. Chlamydiae were cultured from the jejunum of two mice and the spleen of one, but could not be identified at these sites by other methods. Immunofluorescence with an anti-chlamydia mAb was useful for detecting chlamydial antigen in formalin-fixed paraffin wax-embedded samples.

Animals↗
PubMed1982

Pyosemia and carriage of chlamydia and ureaplasma in infertile men.

Chlamydia trachomatis and Ureaplasma urealyticum have been implicated as causative organisms in infections involving the male and female urogenital tracts. Seminal fluid, anterior urethral swabs and first-voided urine specimens from men undergoing infertility evaluation, with and without pyosemia, or anterior urethritis were cultured for Chlamydia trachomatis and Ureaplasma urealyticum. The method used to isolate Chlamydia trachomatis involved cytochalasin-B treated McCoy cells, and NYC and A7 solid media were used for the isolation of Ureaplasma urealyticum. Isolation of Chlamydia trachomatis from seminal fluid has not been possible even in the face of pyosemia and the presence of Chlamydia trachomatis in urine and urethral swab material. The reasons for the inability to culture Chlamydia trachomatis will be explored.

Adult↗
PubMed2003

A mathematical model for the investigation of the Th1 immune response to Chlamydia trachomatis.

Chlamydia are bacterial pathogens of humans and animals causing the important human diseases trachoma, sexually transmitted chlamydial disease and pneumonia. Of the human chlamydial diseases, sexually transmitted disease caused by Chlamydia trachomatis is a major public health concern. Chlamydia trachomatis replicates intracellularly and is characterised by a complex developmental cycle. Chlamydia is susceptible to humoral and cell-mediated immunity. Here we investigate the Th1 cell-mediated immune response against Chlamydia-infected cells as the response changes over the chlamydial developmental cycle. We suggest a form for the immune response over one developmental cycle by modelling the change in the number of intracellular chlamydial particles and assume peptides are presented in proportion to the number of replicating forms of chlamydial particles. We predict, perhaps non-intuitively, that persistent Chlamydia should be induced and forced not to return to the lytic cycle. We also suggest that extending the length of the time of the lytic cycle will effectively decrease the required efficacy of the Th1 response to eliminate the pathogen. We produce plots of active disease progression, control and clearance for varying levels of Th1 effectiveness.

Chlamydia Infections↗
PubMed2003

Inhibition of host cell cytokinesis by Chlamydia trachomatis infection.

UNLABELLED: OBJECTIVES. Chlamydia has to replicate in cytoplasmic vacuoles of eukaryotic cells. To understand how chlamydia interacts with host cells during cell division, we examined the effect of chlamydial infection on host cell cycle. METHODS: An immunofluorescence microscopic approach was used. RESULTS: Although the number of cells was significantly reduced in chlamydia-infected cultures, multiple nuclei were detected in the infected cells, indicating that chlamydia inhibited host cell growth by selectively blocking cytokinesis while allowing mitosis to proceed. The chlamydial inhibition of host cell cytokinesis was confirmed with various strains of Chlamydia trachomatis and in several types of host cells. Furthermore, the chlamydial inhibitory effect was found to depend on chlamydial protein synthesis. DISCUSSIONS: These observations suggest that chlamydia may have evolved specific mechanisms for actively blocking host cell cytokinesis.

Animals↗
PubMed1997

Isolation of faecal chlamydia from sheep in Britain and their characterization by cultural properties.

Faeces samples were taken per rectum from sheep on 26 farms in England and Wales and examined for the presence of chlamydia by culture in McCoy cell monolayers. Thirteen of the farms were known to have had abortion outbreaks associated with Chlamydia psittaci (enzootic abortion) and 13 were free of this infection. The chlamydia isolated were characterized by cultural techniques. Chlamydia were isolated from the faeces of lambs on all 26 farms and the prevalence of infection varied form 5-50% on individual farms. There was no significant difference between the proportion of infected lambs on farms where enzootic abortion was present or absent. Lambs first showed infection when they were 3 months old and the prevalence rate of infection increased up to 9 months old. No chlamydia were isolated from the faeces of 316 adult ewes. The chlamydia were identified as enteric rather than abortion type and thus were C. pecorum rather than C. psittaci.

Abortion, Veterinary↗
PubMed2001

Recognition of the 60 kilodalton cysteine-rich outer membrane protein OMP2 by CD4(+) T cells from humans infected with Chlamydia trachomatis.

T cell-mediated immunity is important in the control of chlamydia infection but chlamydia-specific T cells are also implicated in the inflammation and tissue damage which characterize chlamydia associated diseases. To investigate target antigens of the T cell-mediated immune response to chlamydia infection, Chlamydia trachomatis-specific CD4+ T cell clones were isolated from a patient with chlamydia-induced reactive arthritis. T cell immunoblotting indicated that an antigen of approximately 60 kilodaltons molecular mass was recognized, and recombinant 60 kilodalton cysteine-rich outer membrane 2 (OMP2) proved to be stimulatory. By using deletion constructs and synthetic peptides an epitope presented by HLA-DRB1*0401 was defined and proved to contain the nonamer peptide within the OMP2 sequence predicted to have the greatest binding affinity for DRB1*0401 The sequence of the epitope is conserved in all C. trachomatis strains but not in C. pneumoniae. Investigation of patients with acute urethritis and additional patients with sexually acquired reactive arthritis showed that OMP2-reactive T cells were readily detectable in peripheral blood and synovial fluid. Thus OMP2 is a target antigen of the T cell-mediated immune response to CT infection.

Antigens, Bacterial↗
PubMed2000

Occurrence of chlamydiae in the genital tracts of sows at slaughter and their possible significance for reproductive failure.

The aim of this study was to investigate further the role of chlamydiae as pathogens in the genital tracts of sows at slaughter. Genital tracts of 101 randomly selected sows were collected and specimens of genital tract localizations were systematically examined for chlamydiae using immunohistochemistry and PCR. In the genital tracts of 10 sows, Chlamydia psittaci DNA was detected by PCR, and was further typed as 'serotype 1' in nine cases and as avian strain 6 BC in one animal. However, all specimens examined by immunohistochemistry were negative for chlamydiae. Pooled samples of scalding tank water were additionally investigated for 95 animals. Of these samples, 63.2% contained chlamydial DNA, mostly C. trachomatis, and in one sample C. psittaci 'serotype 1'. Although in most cases contamination through influx of faecally contaminated scalding water is a possible reason for the positive PCR results in the genital tract, latent infection cannot be excluded. In conclusion, the results obtained suggest that chlamydiae are of no or only minor importance in the examined group of Swiss breeding sows. Nevertheless, the role and significance of chlamydiae as pathogens in porcine reproductive disorders remain unresolved and require further investigation.

Animals↗
PubMed2000

Chlamydia trachomatis and human papillomavirus infection in Indian women with sexually transmitted diseases and cervical precancerous and cancerous lesions.

OBJECTIVES: Sexually transmitted diseases (STDs) and anogenital cancers are the major health problems in Indian women but no reliable estimate of the prevalence of either genital chlamydial infection or human papillomavirus (HPV) infection in STD patients is available. The aim of this study was to detect the frequency of Chlamydia trachomatis and the most prevalent high-risk HPV type 16 (HPV 16) infection in Indian women, with STDs and precancerous and cancerous lesions of the uterine cervix by polymerase chain reaction (PCR), and their comparison with those of conventional serology and antigen tests used for C. trachomatis detection. METHODS: Endocervical swabs or scrapes were collected from 50 women with STDs and 30 normal healthy women attending the STD clinics of Smt. Sucheta Kripalani Hospital, New Delhi. Scraped cervical cell specimens were also collected from 50 women with precancerous and cancerous lesions of the uterine cervix. Detection of C. trachomatis and HPV was carried out by PCR using chlamydia and HPV genome-specific oligonucleotide primers. The detection of chlamydial antigen and IgG-specific antibodies was carried out by enzyme immunoassay (EIA) and serological enzyme-linked immunosorbent assay (ELISA), respectively. RESULTS: A chlamydia plasmid-based PCR assay detected 50% (25 of 50) positivity of C. trachomatis in STD patients and HPV 16 DNA was found in 30% (15 of 50) of these cases which are significantly higher than those found in healthy controls. The PCR estimate of chlamydia was found to be higher than its reported frequency by tissue culture. The EIA could detect chlamydial antigen in only 13 cases (26%) while serological ELISA revealed evidence of chlamydia IgG-specific antibodies in 26 (52%) cases. Interestingly, in women with precancerous and cancerous lesions, the rate of HPV 16 infection was very high (52% and 72%, respectively), whereas the frequency of chlamydia infection was found to be 12-22% only. Occurrence of other sexually transmitted agents was also evaluated in the women. CONCLUSIONS: This is the first PCR estimate of genital chlamydial (50%) and HPV 16 (30%) infection in STD patients and women with precancerous and cancerous lesions of the uterine cervix in India. The PCR method seems to be a good alternative to tissue culture.

Adolescent↗
PubMed2002

Chlamydia trachomatis - the agent.

Chlamydiae are obligate intracellular bacteria, parasitizing eukaryotic cells. Chlamydia trachomatis, C. psittaci and C. pneumoniae are the three species of chlamydiae pathogenic to humans. C. trachomatis shows a tropism for the genital and conjunctival epithelia and consists of 19 different serovars which are pathogenic predominantly for the urogenital tract.A distinguishing feature of chlamydiae is their transition between the infectious elementary body that enters the host cell and the non-infectious reticulate body that replicates intracellularly within an inclusion that does not fuse with lysosomes. Chlamydiae depend for some functions upon the host cell; in particular, chlamydiae have little capacity for generating energy. The complete sequence of the 1000-kb chromosome of C. trachomatis is known, as are most of the genes located on the 7.5-kb cryptic plasmid. Recently, several concepts about the biology and the metabolic pathways of C. trachomatis have been revised in relation to the genome sequence, and different novel proteins have been described.

Chlamydia Infections↗
PubMed2002

The intracellular life of chlamydiae.

The ability to cause persistent infection is one of the major characteristics of all chlamydial species in their appropriate hosts. Persistent infection with Chlamydia trachomatis and Chlamydia pneumoniae has been implicated in the pathogenesis of many chronic diseases, some initially not thought to be infectious, including pelvic inflammatory disease, arthritis, asthma, and atherosclerosis. Chlamydiae have a unique developmental cycle with morphologically distinct infectious and reproductive forms: elementary (EB) and reticulate bodies (RB). Chlamydiae appear to circumvent the host endocytic pathway and inhabit a nonacidic vacuole that is dissociated from late endosomes and lysosomes. Chlamydiae also have been demonstrated to enter a persistent state after treatment with cytokines such as interferon-gamma (IFN-gamma), treatment with antibiotics, or restriction of certain nutrients, or to enter this state spontaneously under certain culture conditions. While the organism is in the persistent state, metabolic activity is reduced, and the organism is often refractory to antibiotic treatment. Ultrastructural analysis of IFN-gamma-treated C pneumoniae demonstrates atypical inclusions containing large reticulate-like aberrant bodies with no evidence of redifferentiation into EBs. Persistent C pneumoniae infection appears to be associated with continued expression of genes associated with DNA replication but not with those genes involved with bacterial cell division. The latter observation may explain the appearance of the large abnormal RBs seen in ultrastructural studies. Studies of the association of chlamydiae with chronic disease have been hampered by difficulties in diagnosing chronic, persistent infection with the organism, which, in turn, render determining the efficacy of antibiotic therapy very difficult.

Adult↗
PubMed2000

Feline infectious pneumonia: a short literature review and a retrospective immunohistological study on the involvement of Chlamydia spp. and distemper virus.

A short literature review of feline infectious pneumonia, feline Chlamydia and Paramyxoviridae is presented. In a retrospective study (from 1987 to 1996) 245 cases of feline pneumonia or conjunctivitis/rhinitis were investigated: histological diagnoses and aetiologies were compared; all lungs were examined immunohistologically for the occurrence of chlamydia and of canine distemper virus (CDV), but neither pathogen could be demonstrated. The results confirm previous reports indicating that feline chlamydia is not a primarily pulmonary pathogen and that CDV is not a causative agent of pneumonia in cats as it is in large felids. The review provides a summary of the known causes and pathology of infectious pneumonia in cats (in order of frequency), although some remain aetiologically uncertain. It focuses on chlamydia and distemper virus - a recognized and as yet unknown cause of feline pneumonia. The role and especially the frequency of chlamydia as a cause of feline pneumonia are controversial but distemper virus, known to cause pneumonia in dogs and large felids, has not as yet been demonstrated in cats. The aims of the retrospective study were to determine the occurrence of chlamydia in 245 cases of feline pneumonia or conjunctivitis/rhinitis, and to investigate the presence of CDV in these lungs.

Animals↗
PubMed1988

[Detection of Chlamydia trachomatis in routine clinical practice: increased sensitivity of cell culture in comparison with the microimmunofluorescence test].

Recently, direct immunofluorescence staining has been reported as a new tool for detection of Chlamydia trachomatis. This assay is based on monoclonal antibodies directed against a protein present in all serological variations of Chlamydia known to date. In order to evaluate whether immunofluorescence staining could substitute for the time-consuming, expensive tissue culture technique, urethral and cervical swabs of 131 patients treated for sterility were examined for infection with Chlamydia by both methods. The tissue culture technique, based on cultivation of Chlamydia in mammalian cells, was regarded as 100% sensitive and specific. Employing this method, we demonstrated infection with Chlamydia in 20 patients (15.3%). Colonization of both, cervix and urethra was found in 11.5%, whereas solitary colonization of cervix and urethra was found in 2.3 and 1.5% respectively. However, the immunofluorescence assay applied ("Micro-Trak", Syva Company) showed positive results in only 6 out of 20 cases as determined by tissue culture, thus yielding a sensitivity of 30%. Out of 111 patients with negative results in the tissue culture, 108 were detected by immunofluorescence staining, amounting to a specificity of 97.3%. With special regard to the low sensitivity of the direct immunofluorescence assay, our results indicate a superior, yet unequalled role of the tissue culture technique for detection of Chlamydia trachomatis.

Bacteriological Techniques↗
PubMed1987

[Chlamydia trachomatis--histomorphologic finding in infection of the uterine cervix].

Uterine cervix biopsies from 20 women, in whom cell cultures were chlamydia-positive, were compared with 20 biopsies from chlamydia-negative women on the basis of inflammatory changes and proliferative epithelial reactions. There was a tendency towards severe chronic lymphocytic inflammations, especially those associated with the rare clinical picture of follicular cervicitis, and towards acute erosive forms and microabscesses to be found more frequently among the chlamydia-positive women. Hyperplasia of the reserve cells, which was probably connected with the more severe inflammatory reactions, with normotypical and dysplastic proliferations, was also seen more frequently in the chlamydia-positive group. The difficulty of distinguishing hyperplastic reserve cells from dysplastic squamous epithelia in cytological smears offers an explanation why such cases are relatively frequently overrated in cytological diagnosis. No chlamydia-typical changes of the cell nuclei or of the cytoplasm were found. It thus appears impossible to detect chlamydia in routine histological diagnosis.

Biopsy↗
PubMed2005

Do the characteristics of sexual health centre clients predict chlamydia infection sufficiently strongly to allow selective screening?

OBJECTIVES: This study aimed to estimate chlamydia prevalence and risk factors for infection and to assess the performance of chlamydia-selective screening criteria among clients attending a large sexually transmitted infection (STI) clinic. METHODS: Computerised records for all attendances between 1 July 2002 and 30 June 2003 were analysed. Chlamydia prevalence and risk factors for infection were determined for all new clients. The sensitivity and specificity of risk factors for chlamydia were assessed. RESULTS: 2642 male and 2084 female new clients were tested for chlamydia with a prevalence of 7.3% (95% CI: 6.3%, 8.4%) among men and 3.9% (95% CI: 3.1%, 4.9%) among women. Screening heterosexual men based on a positive contact or symptoms of non-specific urethritis or any two of age <25 years, 4+ partners last 12 months, inconsistent condom use or not presenting for an asymptomatic screen detected 88% of infections by screening 62%. Screening women based on a positive contact or injecting drug use or any two of age <25 years, 2+ partners last 12 months or inconsistent condom use would detect 86% of infections by screening 57%. CONCLUSIONS: Selective screening could be used to more efficiently identify heterosexual men and women at risk of chlamydia.

Adult↗
PubMed1992

Screening for Chlamydia trachomatis in college women on routine gynecological exams.

Chlamydia trachomatis infection poses a serious threat to sexually active college women. Past research has demonstrated the difficulty of predicting infection on the basis of symptoms or physical exam. Recent studies highlight the prevalence of asymptomatic chlamydia infections. This study presents the results of screening 2,303 women for chlamydia infection on routine annual gynecological examinations at a college health center during a 22-month period. A prevalence of 6% was found. The study also assessed the differences between the 140 women identified as chlamydia positive and a control sample of 140 women who were chlamydia negative. The authors compared groups for signs and symptoms that might predict infection, but found no useful predictors. In fact, 79% of the patients who tested positive had no symptoms, and 58% of these had no signs, symptoms, or concurrent infections. Routine screening of women on annual gynecological exam is necessary to bring the chlamydia epidemic under control, the authors conclude.

Adolescent↗