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At least 19 recordsLinked to original sources

PubMed1992

PCR detection and differentiation of Chlamydia pneumoniae, Chlamydia psittaci and Chlamydia trachomatis.

A PCR-based system was developed for the detection and differentiation of Chlamydia trachomatis, Chlamydia psittaci and Chlamydia pneumoniae. A conserved 145 bp fragment of the chlamydial omp1 gene was amplified from all three species. The three species were then differentiated from each other by digestion of this PCR product with restriction enzymes Eco RI and either Hind III or Pst I. The system was shown to work for two strains of C. pneumoniae, 11 strains of C. psittaci and 10 serovars of C. trachomatis, and had a sensitivity of less than 10 chlamydial elementary bodies. This method was also applicable to the detection of C. trachomatis in conjunctival and nasopharyngeal swabs.

Adult↗

PubMedDate not supplied

Detection of IgM antibodies to Chlamydia trachomatis, Chlamydia pneumoniae, and Chlamydia psittaci from Japanese infants and children with pneumonia.

Chlamydia trachomatis (C. trachomatis) is now well established as a pathogen of neonatal inclusion conjunctivitis and infantile pneumonia. C. pneumoniae (TWAR) and C. psittaci also cause pneumonia and other respiratory infections. Serum samples from 223 Japanese infants and children with pneumonia were tested for IgM antibodies to C. trachomatis, C. pneumoniae and C. psittaci. IgM antibodies to C. trachomatis were measured by an enzyme immunoassay (EIA) and by a microimmunofluorescence (MIF) test. IgM antibodies to C. pneumoniae and C. psittaci were determined by MIF. Of 223 patients, 48 (21.5%) were positive for IgM antibodies to C. trachomatis, 11 (4.9%) were positive for C. pneumoniae and 5 (2.2%) were positive for C. psittaci. From nasopharyngeal swabs collected from 87 infants with pneumonia (0 to 1 year of age), we attempted to isolate C. trachomatis with tissue culture. C. trachomatis was isolated from 23 (26.4%) of 87 infants with pneumonia, and IgM antibodies to C. trachomatis were detected in 17 (19.5%) of them. Our data suggest a role for chlamydial infection in childhood pneumonia beyond infancy with both C. trachomatis and C. pneumoniae being contributing pathogens.

Adolescent↗

PubMed1992

[An isolation procedure of Chlamydia pneumoniae and Chlamydia trachomatis].

The author devised a method which permits simultaneous isolation and identification of Chlamydia using a slide chamber with 8 wells. Contaminating bacteria were eliminated by filtration with the membrane filter. The procedure allowed isolation of Chlamydia pneumoniae and Chlamydia trachomatis from 11 (10.1%) out of 109 and 10 (9.2%) out of 109 otolaryngologic clinical specimens, respectively. The use of HL cells together with Hela-229 cells had been considered essential to isolate Chlamydia from specimens in this field. The conditions for isolating Chlamydia pneumoniae were similar to those for Chlamydia trachomatis. The slide chamber procedure with membrane filter treated specimens was suitable for simultaneous isolation and culture of various species of Chlamydia and allowed easy differentiation of Chlamydia pneumoniae from Chlamydia trachomatis with identification by the indirect fluorescent-antibody technique. Routine examination of clinical specimens using this procedure should be required in the future in order to better understand chlamydial infections.

Bacteriological Techniques↗

PubMed1979

Erythromycin and lymecycline treatment in chlamydia-positive and Chlamydia-negative non-gonococcal urethritis--a partner-controlled study.

A group of 213 men with non-gonococcal urethritis and their sexual partners were treated either with erythromycin stearate 500 mgx2 for 15 days or with lymecycline 300 mgx2 for 10 or 20 days. Chlamydia trachomatis was isolated from 40% of the men, from 26% of their female partners and from 56% of the partners of men with chlamydia-positive urethritis. One hundred and eighty-one men were available for evaluation of therapy. There were no significant differences between the treatment schedules. The cure rate was 86-90% in men with chlamydia-positive and 89-100% in men with chlamydia-negative urethritis. Four of the 17 chlamydia-positive females treated with erythromycin and 2 of the 20 chlamydia-positive females treated with lymecycline for 10 days still had chlamydia at re-examination.

Chlamydia Infections↗

PubMed1992

Establishment of a particle-counting method for purified elementary bodies of chlamydiae and evaluation of sensitivities of the IDEIA Chlamydia kit and DNA probe by using the purified elementary bodies.

To evaluate the sensitivity of commercially available test kits for detection of chlamydiae, we established a method of purifying Chlamydia trachomatis and Chlamydia pneumoniae elementary bodies (EBs). We then subjected the purified EBs, together with the purified EBs of Chlamydia psittaci, to the IDEIA Chlamydia (IDEIA) and DNA probe test kits to determine the EB numbers at the detection limits. The sensitivities of the test kits were thus compared. The results can be summarized as follows. (i) Intact EBs in the purified preparations were present at 100, 96.3, and 97% for the C. psittaci Cal 10, C. trachomatis L2/434/Bu (L2), and C. pneumoniae TW-183 strains, respectively. The preparations of the L2 and TW-183 EBs contained a few EB envelopes, which reacted with antilipopolysaccharide monoclonal antibodies, as did the intact EBs, indicating that elimination of EB envelopes is not required for testing of the IDEIA kit's sensitivity. (ii) We established a method of counting intact EBs and EB envelopes under a scanning electron microscope after sedimentation of EBs on a coverslip by centrifugation. (iii) The EB numbers per assay at the cutoff level, which is set up in the IDEIA kit, were 9.6 x 10(2), 6.5 x 10(3), and 2.5 x 10(4) for the L2, TW-183, and Cal 10 strains, respectively. When the same EB preparations were applied to the DNA probe kit, the EB number at the cutoff level was 7.5 x 10(3) per assay for the L2 strain, but no reaction occurred for the Cal 10 and TW-183 strains at any EB number, indicating that the DNA probe kit is highly specific for C. trachomatis. Although the IDEIA kit designed for detection of C. trachomatis showed a sensitivity superior to that of the DNA probe, the chlamydial species was not determined by the IDEIA kit.

Bacteriological Techniques↗

PubMed1978

Parasite-specified phagocytosis of Chlamydia psittaci and Chlamydia trachomatis by L and HeLa cells.

Phagocytosis of the 6BC strain of Chlamydia psittaci and the lymphogranuloma venereum 440L strain of Chlamydia trachomatis by L cells and HeLa 229 cells occurred at rates and to extents that were 10 to 100 times greater than those observed for the phagocytosis of Escherichia coli and polystyrene latex spheres. Both species of Chlamydia were efficiently taken up by host cells of a type they had not previously encountered. Phagocytosis of chlamydiae was brought about by the interaction of parasite surface ligands with elements of the host cell surface. The chlamydial ligands were readily denatured by heat, were masked by antibody, and were resistant to proteases and detergents. The host cell components were reversibly removed by proteases. Chlamydial phagocytosis was inhibited when host cells were incubated for many hours with cycloheximide. It was suggested that the presence on the chlamydial cell surface of ligands with high affinity for normal, ubiquitously occurring structures on the surface of host cells is an evolutionary adaptation to intracellular existence. The term parasite-specified phagocytosis was used to describe the efficient phagocytosis of chlamydiae by nonprofessional phagocytes and to distinguish it from the host-specified immunological and non-immunological phagocytosis carried out by professional phagocytes.

Chlamydia trachomatis↗

PubMed1979

[The replication cycle of Chlamydia trachomatis and Chlamydia psittaci: ultrastructural analysis].

An ultrastructural comparative analysis is reported on the replication cycle of six strains of Chlamydia trachomatis, recently isolated, and Chlamydia psittaci strain 6BC, grown in cell cultures. Important morphological distinctions of the bacterial walls are documented. In Chlamydia trachomatis the cell wall seems more rigid. This causes, during the morphogenesis of the elementary body, its separation from the cell membrane with formation of an electron transparent space, which is not demonstrable in Chlamydia psittaci. As a result of this process, the appearance of "ghosts" and "mini reticular bodies" is documented. Budding and multiple fission are suggested as possible mechanisms of replication of Chlamydia trachomatis, in coexistence or/as alternative to binary fission.

Cell Wall↗

PubMedDate not supplied

Chlamydia trachomatis antigen detection by Chlamydiazyme combined with Chlamydia Blocking Reagent verification.

Several options exist for the detection of chlamydial infection in a routine laboratory setting. Enzyme immuno assay (EIA) technology offers rapid turn around of results and is less technically demanding than chlamydial cell culture. In addition, recently introduced EIA confirmatory reagents have the potential to improve the accuracy of EIA detection. We have evaluated one such confirmatory reagent (Chlamydia Blocking Reagent, Abbott Laboratories) to determine the accuracy of the Chlamydiazyme EIA with special regard to interpretation of low absorbance values. An initial series of 192 male urethral specimens showed that use of a lowered cut off level (absorbance value 0.05) compared with that recommended by the manufacturer increased sensitivity of the EIA from 0.73 to 0.83, thus motivating studies on this interpretative modification. Of 1101 EIA reactive specimens, 65% were determined to be chlamydia positive by the Chlamydia Blocking Reagent. The proportion of female cervical specimens that did not confirm positive was elevated compared with male urethral specimens, 43% vs. 5.7% respectively. In samples yielding absorbance from the recommended cut off level to 0.05 (approximately 50% below), the corresponding figures were 78% and 14% respectively. In 85 selected EIA reactive samples, examination by a direct immunofluorescence staining assay (DFA) (MicroTrak, Syva Inc.) revealed elementary bodies in 85% of 67 blocking test positive and in 24% of 18 blocking test negative samples. The possibility that Gram-negative bacteria were responsible for unconfirmed EIA reactive specimens was investigated using bacterial suspensions. While EIA reactivity was noted with several strains for Gram-negative bacteria, both the blocking reagent and DFA correctly verified the absence of chlamydial antigen.(ABSTRACT TRUNCATED AT 250 WORDS)

Antigens, Bacterial↗

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↗

PubMed1979

Arrays of hemispheric surface projections on Chlamydia psittaci and Chlamydia trachomatis observed by scanning electron microscopy.

Scanning microscopy of two strains of Chlamydia psittaci and four strains of Chlamydia trachomatis representative of the wide diversity in origin and behavior of members of the genus revealed patches of regular arrays of hemispheric projections on the surfaces of elementary bodies of all six strains. These distinctive and perhaps unique surface structure are probably present in all populations of chlamydiae.

Cell Membrane↗

PubMed1992

In vitro evaluation of activities of azithromycin, erythromycin, and tetracycline against Chlamydia trachomatis and Chlamydia pneumoniae.

The in vitro activities of azithromycin (CP-62,993; Pfizer), erythromycin, and tetracycline were evaluated by inhibiting Chlamydia trachomatis and Chlamydia pneumoniae, formerly TWAR, propagation in vitro in McCoy cells, HeLa cells, and HL cells. Eleven clinical isolates of C. trachomatis (serovars D, E, F, J, K, and L2) and four strains of C. pneumoniae were tested with an inoculum of 10(3) inclusion-forming units in a 96-well microtiter plate. The MIC ranges of these antimicrobial agents against C. trachomatis were as follows: azithromycin, 0.125 to 0.5 microgram/ml; erythromycin, 0.25 to 0.1 microgram/ml; and tetracycline, 0.0625 to 1.0 microgram/ml. The MBC ranges, calculated from passage into antibiotic-free medium, were as follows: azithromycin, 0.125 to 4.0 micrograms/ml; erythromycin, 0.5 to 8.0 micrograms/ml; and tetracycline, 0.0625 to 4.0 micrograms/ml. The MIC ranges for C. pneumoniae in both HeLa and HL cells were as follows: azithromycin, 0.125 to 1.0 micrograms/ml; erythromycin, 0.0625 to 1.0 microgram/ml; and tetracycline, 0.125 to 1.0 microgram/ml. The MBC ranges were as follows: azithromycin, 0.25 to 1.0 microgram/ml; erythromycin, 0.25 to 1.0 microgram/ml; and tetracycline, 0.125 to 4.0 micrograms/ml. From the results of this in vitro study, azithromycin appears to be an effective antibiotic comparable to tetracycline and erythromycin for use in the treatment of both C. trachomatis and C. pneumoniae infections.

Azithromycin↗

PubMed1992

Multicenter evaluation of the AntigEnz Chlamydia enzyme immunoassay for diagnosis of Chlamydia trachomatis genital infection.

To evaluate the AntigEnz Chlamydia enzyme immunoassay (EIA) (Baxter/Bartels, Issaquah, Wash.), we studied 320 men and 1,209 women attending clinics for sexually transmitted diseases in Baltimore, San Francisco, and Seattle. At examination, two separate swabs were obtained from each patient, one for chlamydial culture and one for EIA. Cervical samples were collected from women, and urethral samples were collected from men. The prevalence of chlamydial infection by culture was 9% in Baltimore (n = 532), 11% in Seattle (n = 500), and 9% in San Francisco (n = 497). To resolve specimens with discrepant culture and EIA results, the EIA transport buffer was centrifuged and the resuspended pellet was stained by direct immunofluorescence to determine whether elementary bodies were present. Overall sensitivity of the AntigEnz Chlamydia assay compared with culture was 87% in men and 86% in women, and overall specificities were 94 and 97%, respectively. Differences between centers were seen, with sensitivities ranging from 76% among men and 79% among women in Seattle to 100% among men and 95% among women in Baltimore. With a true positive considered to be either a culture-positive or an EIA- and direct immunofluorescence-positive specimen, the revised sensitivity was 91% in men and 88% in women. Overall revised specificity was 99% in both men and women. We conclude that in this high-prevalence population, the sensitivity and specificity of this assay compare favorably with those of other noncultural antigen detection tests for the diagnosis of chlamydial genital infection.

Antigens, Bacterial↗

PubMed1992

Infection with a plasmid-free variant Chlamydia related to Chlamydia trachomatis identified by using multiple assays for nucleic acid detection.

Clinical samples in transport media from 40 patients exhibiting pathologies potentially caused by Chlamydia trachomatis infection were analyzed for chlamydial nucleic acid, and the results were compared with those of culture. Chlamydial culture was performed by a shell vial centrifugation method with HeLa 229 host cells. Polymerase chain reaction (PCR) assays were used to detect either regions on a 7.5-kb plasmid characteristic of C. trachomatis (plasmid-PCR) or a segment of the 16S rRNA genes (rRNA-PCR). All PCR results were confirmed by hybridization with probes for the specific amplified products in either a Southern or a dot blot format. An RNase protection (RNP) assay was used to detect genus-specific chlamydial 16S rRNA directly from the clinical samples. The PCR assays detected C. trachomatis but not other bacteria, including Chlamydia spp. C. trachomatis was isolated from six samples which were positive by the rDNA-PCR and plasmid-PCR assays. Five of the culture-positive specimens were positive by the RNP assay. Twenty-two samples were negative by all criteria. Surprisingly, nine samples were positive by rRNA-PCR and RNP assays only. Nucleic acid sequencing of the rRNA-PCR-amplified products indicated a close relationship between the variants and C. trachomatis. The data may indicate an unrecognized process in C. trachomatis infection or that these patients were infected by a variant strain of C. trachomatis which lacks the C. trachomatis-specific plasmid.

Animals↗

PubMed1992

HLA-DP restricted Chlamydia trachomatis specific synovial fluid T cell clones in Chlamydia induced Reiter's disease.

Synovial fluid (SF) mononuclear cells from a patient with Chlamydia trachomatis induced acute Reiter's disease were directly by limiting dilution in a representative protocol using phytohemagglutinin in the cloning medium. Out of 76 alpha beta-TCR+ CD4+ T lymphocyte clones, 7 were shown to specifically recognize C. trachomatis in a proliferation assay. The antigen recognition of these clones was HLA-DP restricted. Unexpectedly, 2 HLA-DR restricted clones showed a proliferative response to Yersinia enterocolitica O3, though the patient had no history of yersinia infection. The high frequency of SF derived T cells with specificity for species-specific chlamydial antigens and the limited diversity of HLA class II restriction of these clones may indicate an oligoclonal synovial T cell response to persistent intraarticular chlamydia.

Adult↗

PubMed1979

Host modification of chlamydiae: differential infectivity for cell monolayers of chlamydiae grown in eggs and monolayers.

Cell monolayer-grown chlamydiae (CGO) differed from egg-grown organisms (EGO) in their increased spontaneous infectivity relative to centrifuge-assisted infectivity for monolayers. For each population spontaneous: centrifuge-assisted infectivity ratios were constant over a wide dose range. Spontaneous infection increased linearly with time and could not be exhausted from either population by prolonged adsorption; there was no change in infectivity ratios in residual supernatants. Further, one passage of EGO through monolayers gave CGO with stable infectivity properties not increased by further cell passage yet reverting on a single passage in eggs. Spontaneous infection of monolayers with EGO gave progeny with the same infectivity ratios as monolayers infected with EGO by centrifugation. The change in properties following EGO infection of monolayers occurred prior to natural release from cells. We conclude that EGO and CGO are two phenotypically distinct, homogeneous populations. The two infection modes are not properties of subpopulations within EGO and CGO. The relationship of these observations on chlamydiae to other possible host-imposed phenomena is considered.

Animals↗

PubMed1992

[The ultrastructure of a new species of Chlamydia--Chlamydia pneumoniae].

The dynamic study of a new Chlamydia species, C. pneumoniae (strain TWAR, isolate TW-480), inoculated into the monolayer culture of cells L-929 was made 24, 48, 72 and 96 hours after inoculation. When compared with C. trachomatis and C. psittaci, C. pneumoniae were found to stand between these two species with respect to the morphology of their intracytoplasmic microcolonies (inclusions): they were round, almost bubble-like, but more densely packed with chlamydiae, surrounded by an undulate membrane, preserving its integrity until the late stages of their development cycle. In cells L-929 C. pneumoniae had a typical development cycle accompanied by the formation of vegetative and spore-like cells, reticular and elementary bodies, as well as intermediate cells, though this process was slower than in C. trachomatis and C. psittaci. Besides normal elementary bodies, many altered ones were formed in the process of the development of C. pneumoniae in cells L-929. Most of these alterations were similar to the process of bacterial L-transformation and could be regarded as the manifestation of chlamydial pathology related to the adaptation to new host cells.

Animals↗

PubMed1979

[A method for the preparation of a Chlamydiae group-specific antigen on hela-229 cells infected with a strain of "Chlamydia trachomatis" for use in the complement fixation test (author's transl)].

A simple method for the preparation of a potent group-specific antigen on HeLa-229 cells infected with MRC-1 (LB) (TRIC/GB/MRC-1 Gf) strain of Chlamydia trachomatis is outlined. HeLa-229 cells are infected (MRC-1 strain, 102 inclusion-forming units per cell) with centrifugation at 4,000 g for 1 h in flat-bottomed vials. The cells are removed by brief trypsinization with 0.25% trypsin and put into 75 cm2 culture flasks (12 x 106 cells by flask) in BHK-21 medium supplemented with foetal bovine serum. The flasks are incubated for 5 days at 37 degrees C. The destroyed cell monolayer and the supernatant are centrifuged at 100,000 g for 1 h. The pellet is collected and resuspended in PBS and subjected to ultrasonic vibration for 30 min. This antigen may be used for detection of complement-fixing antibodies in lymphogranuloma venereum and ornithosis.

Antigens, Bacterial↗

PubMed1979

Host modification of chlamydiae: presence of an egg antigen on the surface of chlamydiae grown in the chick embryo.

Egg-grown chlamydiae (EGO) have a yolk sac antigen assoicated with their surface which is absent from cell monolayer-grown organisms (CGO). EGO infectivity was specifically neutralized by rabbit antiserum to normal yolk sac; CGO infectivity, before or after incubation with normal yolk sac material, was not neutralized. Treatment of EGO with Clostridium welchii culture filtrate, containing phospholipase C, abolished spontaneous infectivity for monolayers and neutralization by anti-yolk sac antiserum but did not affect centrifuge-assisted infectivity. The possible significance of host antigen on the chlamydial surface is considered.

Animals↗