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PubMed2006

Population prevalence of Chlamydia trachomatis and Neisseria gonorrhoeae in the Netherlands. Should asymptomatic persons be tested during population-based Chlamydia screening also for gonorrhoea or only if chlamydial infection is found?

BACKGROUND: Screening and active case finding for Chlamydia trachomatis (CT) is recommended to prevent reproductive morbidity. However insight in community prevalence of gonococcal infections and co-infections with Neisseria gonorrhoea (NG) is lacking. METHODS: Nested study within a large population-based Chlamydia Screening Pilot among 21.000 persons 15-29 year. All CT-positive (166) and a random sample of 605 CT-negative specimens were as well tested for gonococcal infection. RESULTS: Overall Chlamydia prevalence in the Pilot was 2.0% (95% CI: 1.7-2.3), highest in very urban settings (3.2%; 95% CI: 2.4-4.0) and dependent of several risk factors. Four gonococcal infections were found among 166 participants with CT infection (4/166 = 2.4%; 95% CI: 0.1%-4.7%). All four had several risk factors and reported symptoms. Among 605 CT-negative persons, no infection with NG could be confirmed. CONCLUSION: A low rate of co-infections and a very low community prevalence of gonococcal infections were found in this population based screening programme among young adults in the Netherlands. Population screening for asymptomatic gonococcal infections is not indicated in the Netherlands. Although co-infection with gonorrhoea among CT-positives is dependent on symptoms and well-known algorithms for elevated risks, we advise to test all CT-positives also for NG, whether symptomatic or asymptomatic.

Adolescent↗
PubMed1999

Reactivity of a dual amplified chlamydia immunoassay with different serovars of Chlamydia trachomatis.

A study was undertaken with different serovars (D, E, F, L2, MoPn) of Chlamydia trachomatis to determine the analytical sensitivity of a new dual amplified immunoassay (IDEIA PCE Chlamydia) for detecting chlamydial lipopolysaccharide. IDEIA PCE Chlamydia incorporates a polymer conjugate consisting of multiple copies of antibody and enzyme molecules to provide signal amplification. The test was also assessed with different protein A producing strains of Staphylococcus aureus in order to assess whether the use of a multiple antibody conjugate increased nonspecific binding. The detection limits varied for each serovar with a detection limit of 38 IFU/ml obtained with serovar F and 237 IFU/ml obtained with serovar D. The incorporation of the polymer conjugate resulted in a 2-5 fold increase in analytical sensitivity compared to an earlier version of the test using a conventional conjugate. No increase in cross reactivity with protein A producing strains of S. aureus was obtained. The new dual amplified test format offers potential as a sensitive low-cost screening assay for C. trachomatis infections.

Antigenic Variation↗
PubMed2003

[Identification of chlamydia and (or) chlamydia-like microorganisms by light microscopy confirmed by electron microscopy and fluorescent in situ hybridization].

Using light microscopy, we have shown that chlamydia and/or chlamydia-like microorganisms are registered in 20-25% of the healthy part of human population, whereas in patients of the same age with gynecological problems these were found in 40-50%. Commonly, the infection was slightly manifested (less than 5% of cells are infected). These results were confirmed in four months but only in heavily infected patients. The light microscope data are confirmed by observations with electron microscopy, and by FISH hybridization of the total chlamydial DNA on cytological preparations with chlamydial inclusions. In some cases, microcolonies revealed by FISH hybridization occupied the majority of the cytoplasm volume. Occasionally, the DNA material was found on the nuclear surface. It seems likely that in heavily infected cells chlamydia are able to penetrate into the perinucular space.

Chlamydia↗
PubMed2005

[Chlamydia infections in urogenital tract--application of direct immunofluorescence in the diagnostics of Chlamydia trachomatis in the East Bohemian Region of Czech Republic during 1997-2003].

OBJECTIVE: The aim of the study was an evaluation of results of Chlamydia trachomatis antigen detection by means of direct immunofluorescence in samples from patients suspected from this infection. DESIGN: Retrospective study. SETTING: Institute of clinical microbiology, University Hospital and Medical Faculty of Charles University, Hradec Králové. METHODS: Samples from females were swabs from uterine cervix, vagina and urethra, from male urethral swabs; moreover conjunctival swabs, bronchoalveolar irrigation, lower respiratory tract aspirates and sputum. Samples were fixed and "dyed" with monoclonal specific antibody labeled by fluorescent dye in the lab with a commercial diagnostic kit and they were evaluated microscopically after adding a drop of glycerol and covering with a top slide. RESULTS: Within a group of 6126 samples from patients suspected from Chlamydia infection we have found positivity in 14.4%. Of this subgroup 14.1% in samples from genitourinary tract of females and 15.2% in males, 14.1% from conjunctival swabs and 3.7% from lower respiratory tract. According to an age differentiation, positive samples in individual life-decades from genitourinary tract were 0-13-14.4-13.9-13.9 and in females over 60 13.9%. In males the corresponding walues were 0-21.4-15.1-16-13.4 and those over 60 years 16%. So, the highest positivity in our region has been detected in samples from young men aged 20-30, where it is nearly two-fold higher comparison to age-matched females. CONCLUSION: Direct detection of Chlamydia trachomatis antigen with immunofluorescence method still remains a reliable diagnostic tool. But for a control or confirmation of disputable results it is inconditionally necessary to have at least one more method available, e.g. PCR.

Adolescent↗
PubMed1991

[Use of an amplified enzyme immunoassay for the detection of chlamydiae in a suppurative vaginal discharge from cattle with a chlamydia-induced endometritis].

By inoculation of the yolk sac of embryonating hen eggs and a commercial available enzyme amplified immunoassay to detect chlamydial antigen 63 samples of purulent vaginal discharge from heifers with Chlamydia-induced endometritis were tested for chlamydiae. Vaginal mucus samples from 42 slaughter cattle without any signs of vaginitis/endometritis and 14 samples from various pyogenic bovine infections served as controls. Chlamydiae were isolated from 44 of 63 samples from the experimentally infected heifers. None of the 66 controls gave a positive response neither in the yolk sac culture nor in the ELISA. The overall correlation of the ELISA with culture was 89.9%. Analysis of the ELISA-results revealed the discordance between ELISA and culture presumably to be caused by false negative results in the hen egg technique.

Animals↗
PubMed1990

[Immunologic status in cattle naturally infected with the microorganisms Chlamydia trachomatis and Chlamydia psittaci].

In the present paper there is a description of immunological reactions in 12 to 14 months old bullocks, naturally infected by the microorganisms Chlamydia (Ch.) psittaci and Chlamydia trachomatis. In the course of infection by the above-mentioned microorganisms (chlamydia isolated from semen) without any clinical symptoms the activity of leucocytes and polymorphonuclear cells (PMN) in the peripheral blood is variable and the concentrations of serum immunoglobulins (IG) decrease. It has been demonstrated that the infection of bullocks by Ch. trachomatis increases the bacteria absorbing capacity of PMN cells (from 14.2 to 20.1), percent of phagocytic cells in the peripheral blood (from 13.0 to 26.5%). NBT reduction activity both in a spontaneous test (from 3 to 6) and in a stimulated test (from 8 to 12), and also myeloperoxidase activity (from 0.29 to 0.42). In these animals there were also recorded decreases (although not statistically significant) in the concentrations of serum IgG1, IgG2, IgA by about 10% and by about 30% in IgM. In Ch. psittaci-infected bulls leucocyte migration in the peripheral blood decreased (from 4.5 to 2.7 mm). PMN cell adherence (from 50 to 32), lysosome amount (from 0.63 to 0.35 mg per l) also decreased. In these bullocks decreases in the concentrations of serum Ig from 12.2 to 8.2 g per l in IgG1 and from 3.8 to 1.7 g per l in IgM were also proved.

Animals↗
PubMed1989

Evaluation of ofloxacin in the treatment of mucopurulent cervicitis: response of chlamydia-positive and chlamydia-negative forms.

The treatment of mucopurulent cervicitis in nonpregnant women was evaluated in a randomized study. Subjective and objective criteria were used to assess the response of cervicitis to therapy. Forty-three patients (Group I) were treated with Ofloxacin, 100 mg orally twice daily for 10 days, and forty-five patients (Group II) were treated with Ofloxacin, 200 mg orally twice daily for 7 days. Both produced significant improvement in subjective and objective signs of cervicitis; decreasing clinical symptoms, eliminating mucopurulent endocervical findings, and eradicating C. trachomatis. Overall, of the chlamydia-positive form the complete response of Ofloxacin treatment in mucopurulent cervicitis was 18 (60.0%), the partial response was 10 (33.3%), and resistance was 2 (6.6%) of the 30 patients (p = 0.6592). Of the chlamydia-negative form the complete response was 38 (65.5%), the partial response was 20 (34.5%) of the 58 patients (p = 0.9463). C. trachomatis eradication was satisfactory between both treatment regimens; 28 (93.3%) of the 30 women in chlamydia-positive form. This trial shows that both regimens are also beneficial in the treatment of mucopurulent cervicitis either C. trachomatis positive or C. trachomatis negative, and do not differ significantly between both groups (p = 0.1375). No side effects were observed.

Adult↗
PubMed1978

Treatment of Chlamydia-positive and Chlamydia-negative nonspecific and postgonococcal urethritis.

Chlamydial and non-chlamydial nonspecific or postgonococcal urethritis in 132 men was treated with different regimens of chlortetracycline and doxycycline. Chlortetracycline 250 mg four times daily for 12.5-18.5 days given to 70 men resulted in a clinical cure of urethritis in 80% of cases (56/70). There was no difference in the cure rate between chlamydia-positive (40) and chlamydia-negative (30) cases. In no instance was the treatment failure, i.e., re-appearance of urethritis, associated with re-isolation of C. trachomatis. Forty-two men received 4-10 days treatment with chlortetracycline and their cure rate was 67% (28/42). In this group 29 men were initially chlamydia-positive and among this group 12 relapsed. In four cases this relapse was associated with re-isolation of C. trachomatis. In a group of 20 men treated with doxycycline (100 mg daily up to 20 days) the cure rate was 45% (9/20)) only.

Chlamydia Infections↗
PubMed1996

Identification of 2 Chlamydia trachomatis antigens recognized by synovial fluid T cells from patients with Chlamydia induced reactive arthritis.

OBJECTIVE: To identify antigens of Chlamydia trachomatis recognized by synovial T cell clones from patients with reactive arthritis (ReA). METHODS: C. trachomatis specific T cell clones were isolated from synovial fluid of 2 patients with chlamydia induced ReA. The particular antigens/epitopes recognized by these clones were identified using T cell immunoblotting and testing recombinant chlamydial proteins and synthetic peptides. RESULTS: Two sets of clones were shown by immunoblotting to recognize antigens of roughly 60 and 18 kilodaltons (kDa) respectively. By testing recombinant chlamydial proteins these antigens were identified as the 57 kDa heat shock protein and the 18 kDa histone-like protein, Hc1. Mapping the epitope in Hc1 using synthetic peptides identified a peptide containing a sequence motif compatible with binding to HLA-DR1, the restricting antigen for the Hc1 specific clones. CONCLUSION: These are the first 2 chlamydial antigens to be identified as targets of the synovial T cell response in chlamydia induced ReA. Both have properties that are shared with target antigens identified in ReA induced by enteric infection and relevant to the pathogenesis of joint inflammation.

Adult↗
PubMed1997

[Identification of latent forms of Chlamydia trachomatis in the conjunctiva signifying "new interpretation of ocular chlamydia infections"].

Chlamydia trachomatis (CT) sérovar D through K was demonstrated with electron microscopy and biology in 114 patients with bilateral dry eyes. Long time ago latent CT was recognised in conjunctival epithelium of vernal kerato conjunctivitis patients. CT was found in conjunctival section of patients with an extinct trachoma. Aberrants forms of chlamydia bear the responsibility of this long lasting infection. Reticuled body does not product elementary bodies. It becomes an aberrant body which could remain latent during years. DIF and others classical investigations are negatives because abberrant chlamydiae have lost most part of their MOMP albeit keeping immunopathogenicity.

Antibodies, Bacterial↗
PubMed2000

Frequent contamination of Chlamydia trachomatis and Chlamydia pneumoniae strains with mycoplasma. Biological relevance and selective eradication of mycoplasma from chlamydial cultures with mupirocin.

Several strains of Chlamydia trachomatis (CT) and C. pneumoniae (CP) from different sources were screened for mycoplasma contamination using a sensitive nested 16S rDNA polymerase chain reaction-specific for a broad range of mycoplasma species. Five of nine CT and 5/16 CP isolates were contaminated by mycoplasma. Mycoplasma fermentans, M. hyorhinis and M. hominis were found as contaminating agents. To our knowledge no data are available on whether coinfection of chlamydia with mycoplasma alters the biological behavior of chlamydia. Analysis of the biological effect of mycoplasma on chlamydial infection showed a profound mycoplasma-induced reduction of chlamydial growth. Mycoplasma were efficiently eliminated from chlamydial cultures in HEp-2 cells by treatment with mupirocin without affecting chlamydial replication or host cell growth. Two chlamydial strains, C. trachomatis serovar K and one clinical isolate of C. pneumoniae were purged by this method.

Anti-Bacterial Agents↗
PubMed1998

Chronic follicular conjunctivitis associated with Chlamydia psittaci or Chlamydia pneumoniae.

We determined whether patients with chronic conjunctivitis in whom direct fluorescent antibody (DFA) tests revealed genus-specific chlamydial antigens (but not species-specific Chlamydia trachomatis antigens) were infected with Chlamydia psittaci or Chlamydia pneumoniae. Patients were divided into a case group of possible non-trachomatis chlamydial conjunctivitis and a control group of nonchlamydial conjunctivitis on the basis of examination and DFA testing. Species-specific primers were used to amplify C. trachomatis, C. psittaci, and C. pneumoniae DNA with polymerase chain reaction (PCR). Four (27%) of 15 samples from the case group were positive for C. psittaci or C. pneumoniae DNA, whereas none of 24 control samples were positive. Sequencing revealed a C. pneumoniae, an avian C. psittaci, and two mammalian C. psittaci strains. A short course of oral antibiotic treatment appears to be inadequate for patients with non-trachomatis chlamydial conjunctivitis. Ocular infections due to C. pneumoniae and C. psittaci may be more common than previously recognized and can be identified by DFA and PCR.

Adult↗
PubMed1999

Computational analysis of the polymorphic membrane protein superfamily of Chlamydia trachomatis and Chlamydia pneumoniae.

Whole sequence genome analysis is invaluable in providing complete profiles of related proteins and gene families. The genome sequences of the obligate intracellular bacteria Chlamydia trachomatis and Chlamydia pneumoniae both encode proteins with similarity to several 90-kDa Chlamydia psittaci proteins. These proteins are members of a large superfamily, C. trachomatis with 9 members and C. pneumoniae with 21 members. All polymorphic membrane protein (Pmp) are heterogeneous, both in amino acid sequence and in predicted size. Most proteins have apparent signal peptide leader sequences and hence are predicted to be localized to the outer membrane. The unifying features of all proteins are the conserved amino acid motifs GGAI and FXXN repeated in the N-terminal half of each protein. In both genomes, the pmp genes are clustered at various locations on the chromosome. Phylogenetic analysis suggests six related families, each with at least one C. trachomatis and one C. pneumoniae orthologue. One of these families has seen prolific expansion in C. pneumoniae, resulting in 13 protein paralogues. The maintenance of orthologues from each species suggests specific functions for the proteins in chlamydial biology.

Amino Acid Motifs↗
PubMed1996

A 28 kDa major immunogen of Chlamydia psittaci shares identity with Mip proteins of Legionella spp. and Chlamydia trachomatis-cloning and characterization of the C. psittaci mip-like gene.

Chlamydia psittaci strain guinea-pig inclusion conjunctivitis (GPIC) produces a self-limiting ocular infection of guinea-pigs, and this condition is a representative animal model of ocular chlamydial disease. Convalescent guinea-pigs, which are resistant to reinfection, produce antibodies to several elementary-body proteins, including an uncharacterized antigen of 28 kDa. Convalescent guinea-pig sera were used to identify, from a lambda expression library, two overlapping GPIC genomic clones that produced the 28 kDa antigenic protein. Nucleotide sequence analysis revealed that the gene coding for the 28 kDa protein was similar to the mip (macrophage infectivity potentiator) genes from Legionella pneumophila and Chlamydia trachomatis. The GPIC gene and its product were accordingly designated mip and Mip, respectively. Analysis of the regions flanking mip identified three tightly linked open reading frames coding for predicted products with sequence similarity to asparagine tRNA ligase (AspS), rRNA methylase (SpoU), and thioredoxin (TrxA). The arrangement of these genes in GPIC was aspS-mip-spoU-trxA. Sequence analysis of PCR products produced using genomic DNA from an ovine abortion strain of C. psittaci and from C. trachomatis strain LGV-434 demonstrated that the arrangement of mip, spoU and trxA is common among these chlamydiae.

Amino Acid Sequence↗
PubMed2004

Chlamydia trachomatis sigma28 recognizes the fliC promoter of Escherichia coli and responds to heat shock in chlamydiae.

The rpsD gene of Chlamydia trachomatis encodes the alternative sigma factor sigma28, which bears strong homology to many bacterial sigma factors, including Escherichia coli sigma8 and Bacillus subtilis sigmaB and sigmaD. Recently, a sigma28 promoter was identified upstream of the late-cycle-expressed gene hctB, which encodes the Chlamydia-histone-like protein 2 (Yu & Tan, 2003). In this study it is shown that the product of chlamydial rpsD is an E. coli sigma28 homologue. It was found that recombinant chlamydial sigma8, in combination with E. coli core RNA polymerase, initiates transcription in vitro from the E. coli sigma28-dependent promoter of fliC. It was also demonstrated that the recombinant chlamydial sigma28 does not recognize major sigma factor sigma70-consensus-like sequences in vitro. In C. trachomatis-infected cells, two rpsD transcripts were detected with 5' ends located 18 (transcript I) and 54 bp (transcript II) upstream of the translational initiation codon at 16 and 30 h post-infection. When the temperature of cultures infected with C. trachomatis was shifted from 35 to 42 degrees C, the rpsD transcript I increased dramatically. The levels of chlamydial sigma28, relative to EF-Tu, were greater throughout the exponential growth phase of the reticulate body, but lower late in the developmental cycle. These data support the hypothesis that sigma28 plays a role in the regulatory network that allows chlamydiae to survive changes in its environment, enabling it to complete its unique developmental cycle.

Bacterial Proteins↗
PubMed1993

In vitro transcription in Chlamydia psittaci and Chlamydia trachomatis.

Extracts of Chlamydia psittaci and Chlamydia trachomatis were used to transcribe molecularly cloned chlamydial genes in vitro. The extracts were prepared by lysing reticulate bodies, obtaining the 10,000 x g centrifugation pellet, and eluting RNA polymerase from the pellet by treatment with 2M KCl to yield a fraction designated SS2. Some in vitro transcription was initiated from non-chlamydial promoters and a small amount of transcription was from endogenous DNA template in SS2. However, optimal transcription from exogenous templates required chlamydial promoter sequences, and primer extension analysis indicated that chlamydia promoter-specific in vitro transcription was initiated from the same start sites recognized in vivo. A monoclonal antibody that was generated against Escherichia coli sigma 70 and which immunologically cross-reacts with C. trachomatis sigma 66 inhibited in vitro transcription of vector and cloned chlamydial DNA, suggesting that transcriptional initiation in the SS2 fraction is mediated by sigma 66. An in vitro transcription assay based on detection of transcripts of specific lengths was applied to the chlamydial system; this assay and others described here should be useful in defining chlamydial promoters and other transcriptional regulatory elements.

Base Sequence↗
PubMed1997

Evaluation of Chlamydia immunoglobulin M (IgM), IgG, and IgA rELISAs Medac for diagnosis of Chlamydia pneumoniae infection.

Chlamydia pneumoniae is an important pathogen responsible for a variety of respiratory diseases in humans. Cell culture remains the most specific method for C. pneumoniae diagnosis, but it is labor-intensive and time-consuming. Thus, serology, particularly microimmunofluorescence (MIF) testing, is frequently utilized. However, the MIF test has a significant subjective component. We evaluated a new serological test: Chlamydia Immunoglobulin M (IgG, IgA, and IgM rELISAs Medac, based on a recombinant Chlamydia-specific lipopolysaccharide (LPS) fragment, for the diagnosis of C. pneumoniae infection. The results of this study demonstrated that the use of rELISAs Medac with single sera does not appear to be sensitive or specific for diagnosis of C. pneumoniae infection compared to culture. In children, sensitivities of the rELISAs compared to culture did not exceed 34.2%, and the specificities ranged from 68.4% (IgG) to 91.2% (IgA). In adults, the sensitivities of the rELISAs were slightly higher, up to 77.8% (IgA or IgG), but the specificities ranged from a very low 20.8% for IgA or IgG to 81.1% for IgM. When multiple sera were tested, the results of the rELISAs Medac correlated with culture results in five of eight (62.5%) patients. However, this offers only a retrospective diagnosis, which makes it difficult to manage these patients prospectively.

Adolescent↗
PubMed1981

Localization of chlamydial group Antigen in McCoy cell monolayers infected with Chlamydia trachomatis or Chlamydia psittaci.

Chlamydial inclusions were demonstrated by indirect immunofluorescence (IF) with antiserum to the chlamydial group antigen when McCoy cell monolayers infected with either Chlamydia trachomatis or Chlamydia psittaci were fixed in formaldehyde or paraformaldehyde, provided the monolayer was not allowed to dry. If these monolayers were then air dried and restained by IF with the same antiserum but with a different fluorescence conjugate, group antigen associated with inclusion-containing McCoy cells but independent of the inclusions was revealed. This antigen was not restricted to infected cells but appeared to radiate out from them, suggesting that group antigen was released from infected cells. Similar host cell-associated antigen could be shown by IF of glutaraldehyde-fixed, air-dried monolayers, but inclusions could not be stained by IF before these preparations were dried, presumably because antibody could not penetrate glutaraldehyde-fixed cells. Electron microscopic immunoperoxidase studies of paraformaldehyde-fixed, wet monolayers located group antigen within inclusions on the outer membrane of chlamydial organisms and on single-membrane vesicles. However, when dried monolayers were labeled with the same immunoperoxidase technique, no intracellular labeling occurred, but dense staining was seen at the surface of infected cells and on adjacent membranous material. These observations are compatible with the postulate that replicating chlamydiae produce outer membrane blebs containing group antigen, which are excreted by the host cells during the chlamydial developmental cycle.

Antigens, Bacterial↗