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 1,153 records · Page 64Linked to original sources
PubMed2003

Gonorrhea prevalence and coinfection with chlamydia in women in the United States, 2000.

BACKGROUND: No recent national data address the prevalence of gonorrhea. GOAL: The goal was to describe gonorrhea prevalence and chlamydial coinfection among women aged 15 to 24 years. STUDY DESIGN: Data were analyzed from tests for chlamydia and gonorrhea at family planning, STD, and prenatal clinics in 2000. Gonorrhea positivity, chlamydia positivity among women with gonorrhea, and the median and interquartile ranges (IQRs) were calculated. RESULTS: The median state-specific gonorrhea positivity among women aged 15 to 24 years was 0.9% (IQR, 0.7%-1.7%) in family planning clinics, 7.0% (IQR, 4.1%-10.4%) in STD clinics, and 1.0% (IQR, 0.8%-1.6%) in prenatal clinics. Gonorrhea positivity was higher among females aged 15 to 19 years than among those aged 20 to 24 years. Median chlamydia positivity for females infected with gonorrhea was highest among those aged 15 to 19 years (46%). CONCLUSIONS: Gonorrhea positivity was consistently highest among women aged 15 to 19 years; almost half of women aged 15 to 19 years with gonorrhea also had chlamydia.

Adolescent↗
PubMed2000

Microvirus of chlamydia psittaci strain guinea pig inclusion conjunctivitis: isolation and molecular characterization.

The authors report the isolation and molecular characterization of a bacteriophage, φCPG1, which infects CHLAMYDIA: psittaci strain Guinea pig Inclusion Conjunctivitis. Purified virion preparations contained isometric particles of 25 nm diameter, superficially similar to spike-less members of the φX174 family of bacteriophages. The single-stranded circular DNA genome of φCPG1 included five large ORFs, which were similar to ORFs in the genome of a previously described CHLAMYDIA: bacteriophage (Chp1) that infects avian C. psittaci. Three of the ORFs encoded polypeptides that were similar to those in a phage infecting the mollicute Spiroplasma melliferum, a pathogen of honeybees. Lesser sequence similarities were seen between two ORF products and the major capsid protein of the φX174 coliphage family and proteins mediating rolling circle replication initiation in phages, phagemids and plasmids. Phage φCPG1 is the second member of the genus CHLAMYDIAMICROVIRUS:, the first to infect a member of a CHLAMYDIA: species infecting mammals. Similarity searches of the nucleotide sequence further revealed a highly conserved (75% identity) 375 base sequence integrated into the genome of the human pathogen Chlamydia pneumoniae. This genomic segment encodes a truncated 113 residue polypeptide, the sequence of which is 72% identical to the amino-terminal end of the putative replication initiation protein of φCPG1. This finding suggests that C. pneumoniae has been infected by a phage related to φCPG1 and that infection resulted in integration of some of the phage genome into the C. pneumoniae genome.

Amino Acid Sequence↗
PubMed1995

Molecular cloning, sequence analysis, and functional characterization of the lipopolysaccharide biosynthetic gene kdtA encoding 3-deoxy-alpha-D-manno-octulosonic acid transferase of Chlamydia pneumoniae strain TW-183.

The gene kdtA of Chlamydia pneumoniae strain TW-183, encoding the enzyme 3-deoxy-alpha-D-manno-octulosonic acid (Kdo) transferase of lipopolysaccharide biosynthesis, was cloned and sequenced. A single open reading frame of 1314 bp was identified, the deduced amino acid sequence of which revealed 69% similarity and 43% identity with KdtA of Chlamydia trachomatis and Chlamydia psittaci. The gene was expressed in the Gram-positive host Corynebacterium glutamicum and the primary gene product was characterized as a multifunctional glycosyltransferase. Cell-free extracts generated in vitro the genus-specific epitope of Chlamydia composed of the trisaccharide alphaKdo(2-8)alphaKdo(2-4)alphaKdo. The results show that a single polypeptide affords three different glycosidic bonds, which is in contradiction to the dogma of glycobiology: 'one enzyme - one glycosidic bond'.

Amino Acid Sequence↗
PubMed1993

Endometritis in cattle experimentally induced by Chlamydia psittaci.

On the day of estrus, eight virgin heifers received intrauterine inoculations of yolk sac propagated Chlamydia psittaci strain BovEnd 11/88 isolated from the uterus of a slaughter cow. All heifers developed purulent vaginal discharge which persisted for 3 to 7 weeks. Chlamydiae or chlamydial antigen were detected in vaginal and uterine discharges of infected animals by culture or Capture ELISA, while other bacterial pathogens were not found. In sera of the chlamydia-infected heifers marked increases in antibody titres against the chlamydial genus-specific LPS-antigen were found by ELISA and complement fixation test. Six heifers were artificially inseminated in 5 successive cycles beginning at the first estrus following intrauterine inoculation. In two of the infected heifers spontaneous healing of endometritis occurred after 5 estrus cycles. Only these animals conceived after the 5th breeding, whereas in the remaining four animals a chlamydia-associated chronic endometritis was recognized as the cause of infertility in the 19th and 26th week p.i. at slaughter. Two control heifers which remained clinically normal after intrauterine exposure to sterile yolk sac-suspensions conceived at the 1st and 2nd service, respectively.

Animals↗
PubMed2006

Serology of Chlamydia pneumoniae in patients with chronic cough.

OBJECTIVE AND BACKGROUND: Chronic cough is one of the more common respiratory symptoms. Controversy exists as to whether Chlamydia infection is associated with chronic cough. As such, the association of chronic cough with serological evidence of Chlamydia pneumoniae (C. P) infection and a systemic inflammatory marker was assessed. METHODS: Thirty-seven patients who visited Kangwon National University Hospital for chronic cough between September 2003 and August 2004 and 37 age-matched healthy controls were evaluated for C. P. antibodies and C-reactive protein. Chronic infection was defined as an IgG or IgA titre between 1:64 and 1:512, and acute infection was defined as IgM=1:16 or IgG titre of=1:512 or IgA=1:512. A nasopharyngeal swab was evaluated for C. P. DNA using the polymerase chain reaction. RESULTS: The median duration of cough was 3 months (1-240). Nineteen patients (49%) and 19 controls had titres consistent with chronic infection, and the titre difference was not significant (P=0.592). Nine patients and two controls had titres consistent with acute infection (24.3% vs. 5.4%). Acute infection was significantly more prevalent in the patients with chronic cough (P=0.023). There was no difference in the C-reactive protein value (0.13 vs. 0.14, P=0.84). Three patients were positive for C. P. DNA. CONCLUSION: Acute Chlamydia infection was more prevalent in patients with chronic cough, whereas chronic Chlamydia infection was not. There was no elevation of a systemic inflammatory marker in patients with chronic cough.

Adult↗
PubMed1996

Chlamydia pneumoniae and cardiovascular diseases.

Chlamydia infection of the cardiovascular system is associated with pericarditis, endocarditis and myocarditis. Chlamydia particles can also be observed in damaged heart valves. There is now good evidence that the lesions of arteriosclerosis and aortic aneurysm as well as valvular disease may be associated with C. pneumoniae infection. Patients with acute myocardial infarction show seroconversion against Chlamydia lipopolysaccharide. In a prospective study of 4000 healthy hypercholesterolemic men, signs suggestive of chronic C. pneumoniae infection increased the risk of a cardiac event three---fold. This risk factor is synergistic with the smoking risk. Immunohistochemistry also demonstrated Chlamydia lipopolysaccharide in samples of aortic aneurysm. Chlamydial inflammation may play a role in the oxidation of low density lipoprotein in atherosclerotic lesions.

Journal Article↗
PubMed2004

Prevalence of viable Chlamydia pneumoniae in peripheral blood mononuclear cells of healthy blood donors.

BACKGROUND: Demonstration of viable Chlamydia (Chlamydophila) pneumoniae in peripheral blood mononuclear cells (PBMNCs) is essential to understand the involvement of C. pneumoniae in atherosclerosis. Nevertheless, the prevalence of viable C. pneumoniae in the blood of healthy donors has not yet been studied. STUDY DESIGN AND METHODS: The presence of C. pneumoniae transcript in PBMNCs from blood of healthy human donors was assessed by real-time reverse transcription-polymerase chain reaction (RT-PCR) with primers for C. pneumoniae 16S rRNA, which is more sensitive than genomic-DNA-based analysis, and by the use of staining with fluorescein isothiocyanate-conjugated chlamydia monoclonal antibody (MoAb). RESULTS: Thirteen of 70 donors (18.5%) showed the presence of bacterial transcript in cultured PBMNCs. The prevalence of bacterial detection and bacterial numbers was significantly increased in PBMNC cultures incubated with cycloheximide. Immunostaining of PBMNCs with antichlamydial MoAb also revealed the presence of bacterial antigen in the PBMNCs judged as positive. Nevertheless, cultivation of C. pneumoniae from all PCR-positive donors was unsuccessful. There was no significant correlation between the presence of chlamydia and either sex or current smoking habits. A possible age variation, however, in the presence of chlamydia in blood of healthy donors was suggested by the results obtained. CONCLUSION: The bacterial transcripts in PBMNCs obtained from healthy donors were detected by the RT-PCR method. Viable C. pneumoniae may be present in healthy human PBMNCs.

Adult↗
PubMed2001

PCR-based method for isolation and detection of Chlamydia pneumoniae DNA in cerebrospinal fluids.

Since current studies indicate the possible involvement of Chlamydia pneumoniae in the pathogenesis of multiple sclerosis (MS), demonstration of C. pneumoniae in the cerebrospinal fluid (CSF) of patients with MS is highly desirable. However, there is controversy concerning the detection of C. pneumoniae in CSFs from MS patients due to the lack of a standard protocol for extraction and detection of C. pneumoniae DNA. In this regard, we attempted to establish a highly effective extraction protocol for C. pneumoniae DNA from CSFs utilizing a commercial kit and a PCR detection method. The extraction and PCR detection protocol established in this study succeeded in detecting as few as 20 C. pneumoniae organisms in 200 microl of mock CSF. The use of this protocol to detect C. pneumoniae DNA in CSFs revealed that 68% of CSF samples obtained from patients with MS were positive (11 out of 16 samples) for chlamydia DNA. Thus, the protocol established here is sensitive enough to detect chlamydia DNA from CSFs and can be used by other laboratories for evaluation of the presence of chlamydiae in CSFs because the protocol is based on the use of a commercial kit.

Chlamydophila Infections↗
PubMed2001

Evaluation of Chlamydia pneumoniae 43- and 53-kilodalton recombinant proteins for serodiagnosis by Western Blot.

Chlamydia pneumoniae is a common cause of respiratory infection. It has also been shown to be associated with coronary heart disease. Two proteins that have been reported to be recognized frequently during human infection are proteins having molecular masses of 43 and 53 kDa. In order to develop a useful alternative serological test to the microimmunofluorescence (micro-IF) assay, recombinant 43-kDa and 53-kDa chlamydia-specific proteins were evaluated in dot blot and/or for comparison to the standard micro-IF test. Primers for amplification were derived from genome sequence information for two C. pneumoniae genes (CPn0809 and CPn0980) encoding 53-kDa proteins and four C. pneumoniae genes (CPn0562, CPn0927, CPn0928, and Cpn0929) encoding 43-kDa proteins of unknown function, which were Chlamydia specific and not found in Chlamydia trachomatis. The 53-kDa protein product of CPn0809 or the N-terminal 18-kDa portion had better specificity than any of the 43-kDa recombinants but was much less sensitive than micro-IF. In contrast, the 53-kDa protein encoded by CPn0980 was recognized by 11 of 12 (92%) acute-phase sera, 35 of 46 (76%) chronic sera, 0 of 12 micro-IF-negative sera (C. pneumoniae and C. trachomatis negative), and 1 of 12 (8%) C. pneumoniae negative, C. trachomatis positive sera. Thus, it appears that the 53-kDa protein encoded by CPn0980 has potential use for serodiagnosis of C. pneumoniae infection.

Antigens, Bacterial↗
PubMed1978

Loss of inorganic ions from host cells infected with Chlamydia psittaci.

Mouse fibroblasts (L cells) infected with the 6BC strain of Chlamydia psittaci released potassium ion (K(+)) into the extracellular milieu in a way that depended on size of inoculum and time after infection. When the multiplicity of infection was 500 to 1,000 50% infectious units (ID(50)) per L cell, loss of intracellular K(+) was first apparent 4 to 10 h after infection and was nearly complete at 6 to 20 h. Magnesium ion and inorganic phosphate (P(i)) were also released. Similar multiplicities of ultraviolet-inactivated C. psittaci also caused release of K(+). Leakage of inorganic ions probably resulted from immediate damage to the host-cell plasma membrane during ingestion of large numbers of chlamydiae. With multiplicities of 1 to 50 ID(50) per L cell, ingestion of C. psittaci was not by itself enough to cause release of K(+) and P(i) from infected L cells. There was a delay of 36 to 72 h between infection and massive leakage of intracellular ions during which time the chlamydiae multiplied extensively. Fifty ID(50) of ultraviolet-inactivated C. psittaci per L cell did not bring about significant leakage of K(+), even after 72 h. The mechanism whereby these multiplicities of infection destroy the ability of host cells to retain intracellular molecules is not known. HeLa 229 cells also released K(+) and P(i) after infection, but these losses occurred more slowly than in comparably infected L cells, possibly because C. psittaci did not multiply as extensively in HeLa cells as it did in L cells. The significance of the inability of chlamydiae-infected cells to regulate the flow of molecules through their plasma membranes is discussed.

Cell Membrane Permeability↗
PubMed1985

Persistent infection of L cells with an ovine abortion strain of Chlamydia psittaci.

L cells inoculated at multiplicities of infection greater than or equal to 1 inclusion-forming unit of the abortigenic chlamydial strain B577 were destroyed within 10 to 15 days. Upon continued incubation in fresh medium, a few surviving cells repopulated the flasks, and the reemerging cultures remained persistently infected. The persistent state was characterized by cycles of repopulation with a low ratio of infected cells and cycles of extensive cytopathic changes in which greater than 90% of the cells had chlamydial inclusions and which could be delayed or even terminated by penicillin treatment. Immunofluorescence and superinfection during the period of repopulation revealed that the persistently infected cells could adsorb chlamydiae but their multiplication was arrested. This nonpermissive state could be terminated by the specific action of cycloheximide. L cells spontaneously cured from a persistent infection exhibited no change in susceptibility to chlamydiae when compared with normal L cells. However, chlamydiae derived from L cells after 7.5 months of persistence destroyed L-cell monolayers more rapidly and at lower multiplicities of infection than the wild type. This state of chlamydia-host cell interaction could not be established with the arthropathogenic strain LW613 because chlamydial infectivity was lost after the first cytolytic burst of infection in the cell cultures. The persistence described for the strain B577-L-cell system appears to differ from previously described models involving other chlamydial strains.

Abortion, Septic↗
PubMed1995

Potentiation of interferon-mediated inhibition of Chlamydia infection by interleukin-1 in human macrophage cultures.

One mechanism by which interferons (IFNs) can inhibit chlamydial infection is by the induction of the enzyme indoleamine 2,3-dioxygenase (IDO), which restricts the availability of tryptophan, which is required for chlamydial growth. Other immunomodulating agents, including interleukin-1 (IL-1), can interact synergistically with IFNs, resulting in increased IDO activity in macrophages. The objectives of this study were to establish that IL-1 can enhance IFN-mediated inhibition of chlamydial growth by increasing the amount of IDO activity induced by IFNs and to identify immunomodulatory agents in culture supernatants from chlamydia-infected macrophages that interact synergistically with IFNs in restricting chlamydial growth. Monocyte-derived macrophages were treated with IL-1 combined with gamma IFN (IFN-gamma) or IFN-beta. The ability of treated cells to support the growth of Chlamydia psittaci was directly related to the amount of IDO activity induced; as IDO activity increased, so did inhibition of chlamydial growth. Furthermore, concentrations of IFNs were identified at which little IDO activity was induced and chlamydial growth was permitted yet which in the presence of IL-1 resulted in increased IDO activity and restriction of chlamydial growth. The addition of exogenous tryptophan reversed the effect of combined IFN and IL-1 treatment, indicating that IDO activity induced by combined cytokine treatment was responsible for chlamydial inhibition. Supernatants from chlamydia-infected macrophages were capable of potentiating IDO induction by IFN-gamma and of restricting the growth of C. psittaci. Antibody to IL-1 beta neutralized the potentiating effects of supernatants from chlamydia-infected cells on both IDO induction and chlamydial inhibition. Thus, IL-1 produced in response to chlamydial infection may contribute to the elimination of the infection.

Cell Division↗
PubMed1989

Genetic diversity of avian and mammalian Chlamydia psittaci strains and relation to host origin.

Genetic relationships were reported for Chlamydia psittaci derived from psittacine birds, pigeons, turkeys, humans, cats, muskrats, cattle, and sheep and for C. trachomatis, including representative strains of the three biovars, through physical analysis of genomic DNA including DNA fingerprinting with restriction endonuclease SalI, DNA-DNA hybridization in solution with S1 nuclease, and Southern analysis with genomic DNA probes. A total of 26 strains were divided into four groups of C. psittaci and two groups of C. trachomatis, on the basis of DNA fingerprints. The six groups of Chlamydia spp. were related to host origin: two avian groups (Av1 and Av2), one feline and muskrat group (Fe1), one ruminant group (Ru1), one C. trachomatis biovars trachoma and lymphogranuloma group (CtHu), and one C. trachomatis mouse biovar group (CtMo), although an ovine abortion strain belonged to the avian group Av2. DNA-DNA hybridization assay and Southern analysis with genomic DNA probes indicated three DNA homology groups in the genus Chlamydia: an avian-feline group (groups Av1, Av2, and Fe1), a ruminant group (group Ru1), and a C. trachomatis group (groups CtHu and CtMo). Furthermore, the Southern analysis indicated that the homologous sequences (DNA homology of at least 14%) within the avian-feline group were distributed along the whole genome, whereas the homologous sequences (DNA homology of less than 24%) among the three DNA homology groups were localized in distinct regions of the genome DNA. These results suggest that Chlamydia spp. are derived from a common ancestor and have diverged into various groups showing restricted host ranges as a natural characteristic and that the species C. psittaci should be differentiated into groups related to host origin and DNA homology.

Animals↗
PubMed2001

Chlamydia pneumoniae serology: importance of methodology in patients with coronary heart disease and healthy individuals.

Most publications on the relationship between infection with Chlamydia pneumoniae and coronary heart disease (CHD) propose an association, but negative studies are also reported. Seroepidemiological studies vary in the use of different serological methods, different cutoff limits, different sampling times in relation to acute cardiac events, and different clinical stages of CHD. We wanted to compare three different commercially available methods for measuring Chlamydia antibodies to see how the choice of method influenced the prevalence of seropositive individuals in CHD patients and in healthy individuals and to see if sampling time in relation to an acute cardiac event or the stage of atherothrombotic disease influenced the results. Blood samples from 197 CHD patients and 197 individually matched healthy control individuals were tested at baseline and after 6 months; the mean age was 55 years in both groups, and 18% were women. Among the CHD patients, 166 were included at a median of 16 days after an acute cardiac event and 31 had chronic disease with the latest acute event being >3 months earlier. The difference in prevalence of antibodies between the CHD patients and the healthy controls was significant when Chlamydia lipopolysaccharide antibodies were measured, while no significant differences between the study groups were observed by the two methods detecting Chlamydia pneumoniae major outer membrane protein antibodies. The number of seropositive individuals was quite similar at inclusion and 6 months later, and no significant differences were observed between patients with a recent cardiac event and those with a more remote cardiac event. We conclude that the choice of serological method is of major importance when evaluating a possible relationship between C. pneumoniae and CHD.

Adult↗
PubMed1985

Attempted venereal transmission of Chlamydia psittaci in sheep.

Attempts were made to transmit Chlamydia psittaci, the causal agent of enzootic abortion of ewes, in three different ways. Ten ewes were inseminated artificially with freshly collected semen containing 10(5) CELD50 chlamydia. Serological evidence of infection was found two weeks before parturition in nine ewes and the organism was recovered from three of them. By six weeks post partum antibody titres had fallen and were negative in six ewes. Twenty-four hours after service two groups of 10 ewes were infected intravaginally with 10(8) CELD50 and 10(3) CELD50 chlamydia respectively. Positive complement fixation titres were present in the first half of pregnancy in all the ewes in the high dose group but not the low dose group. None of the ewes showed evidence of infection at parturition. Fourteen ewes were served by four rams which had been intravenously infected with 10(8) CELD50 chlamydia four to six days earlier. Following service seroconversion occurred but titres became negative again by late pregnancy. No microbiological evidence of infection was detected in any of the ewes at parturition but complement fixation titres were positive in 12 of 14 ewes sampled six weeks post partum. The 14 ewes were sampled during their pregnancies the next year and none showed any evidence of chlamydial infection. It is concluded that venereal transmission of C psittaci is biologically feasible in sheep, but that under normal systems of flock management in Britain it is unlikely to contribute greatly to the epidemiology of enzootic abortion of ewes.

Abortion, Septic↗
PubMed1976

Alterations in the ultrastructure of Chlamydia psittaci 6BC harvested from the allantoic fluid of chick embryos.

The allantoic fluid of chick embryos infected with Chlamydia psittaci is routinely used as a source of material for the study of the chemical and biological properties of the chlamydiae. We have examined pellets recovered from this allantoic fluid by low- and high-speed centrifugation, as well as high-speed pellets which had been stored at -70 degrees C, and we find that all of the pleomorphic forms of the chlamydiae are present in these materials. The reticulate bodies and large intermediate bodies are always seen to be morphologically damaged in that their cell envelopes are modified and in that they are distended and occasionally 'leaky.' No morphological evidence of damage was seen in small intermediate bodies or in elementary bodies in any of the materials which were examined. Thus the chlamydial population recovered from the allantoic fluid of infected chick embryos has been modified by selective damage to the least-condensed particles. We propose that the release of lysosomal enzymes from the host cell may coincide with the release of the chlamydia and that these enzymes may be responsible for this selective damage.

Allantois↗
PubMed2000

High prevalence of seropositivity for antibodies to Chlamydia-specific lipopolysaccharide in patients with acute coronary syndrome.

BACKGROUND: Results of recent studies have demonstrated that there is an association between infection with Chlamydia pneumoniae and coronary artery disease (CAD). Inflammatory response caused by chlamydial infection has been considered to contribute to the development of atherosclerosis in coronary arteries. OBJECTIVE: The aim of this study was to investigate the specific relations between chlamydial infection and coronary events in patients with CAD. METHODS: We measured serum levels of immunoglobulin A and G antibodies against Chlamydia spp.-specific lipopolysaccharide in 155 patients with CAD and 60 age-matched and sex-matched healthy controls by enzyme-linked immunosorbent assay. CAD patients were divided into groups of the patients with acute coronary syndrome [(ACS), n = 35], old myocardial infarction [(OMI), n = 60] and chronic coronary heart disease [(CCHD), n = 60]. RESULTS: Prevalence of both seropositive antibodies in the control group and CCHD group were not different. In contrast, in ACS group there were significantly higher prevalences of seropositive immunoglobulin A (46 versus 12%, P = 0.0001) and G (74 versus 45%, P = 0.005) antibodies and in OMI group there was a significantly higher prevalence of seropositive immunoglobulin A antibodies (28 versus 12%, P = 0.02). Furthermore, compared with CCHD group, in ACS group there were significantly higher prevalences of seropositive immunoglobulin A (P = 0.00006) and G (P = 0.002) antibodies and in OMI group there was a higher prevalence of seropositive immunoglobulin A (P = 0.01). Adjustment for confounding factors did not change these findings. CONCLUSIONS: Infection with Chlamydia is significantly associated with ACS and OMI, but not with CCHD. These findings suggest that chronic and reactive infection with Chlamydia can lead to disruption of vulnerable plaque in patients with ACS.

Acute Disease↗
PubMed2002

Detection of Chlamydia pneumoniae in unexplained pulmonary hypertension.

The pathogenesis of primary pulmonary hypertension is still unclear. The case of a 68-yr-old female patient who complained of recurrent dizzy spells and collapses over a period of 6 weeks and died of global cardiac failure is presented. Autopsy revealed severe pulmonary hypertension, slight chronic bronchitis, and bronchiolitis as well as intra-alveolar accumulation of macrophages. Chlamydiae were detected within the pulmonary arteries and in intramural and intra-alveolar macrophages by immunofluorescence, confocal laser scanning microscopy, scanning and transmission electron microscopy. Nested-polymerase chain reaction (PCR) and nonradioactive deoxyribonucleic acid (DNA) hybridization of PCR products from pulmonary arteries revealed Chlamydia pneumoniae DNA. Chlamydia pneumoniae has already been detected in atherosclerosis and in pulmonary emphysema. It can induce proliferation of smooth muscle cells. Chlamydia pneumoniae might be relevant in aggravation of primary pulmonary hypertension and might perhaps be a trigger factor in some cases.

Aged↗