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Results for “Chlamydiaceae Infections”

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At least 19 recordsLinked to original sources
PubMed2005

Evaluation of lung function in pigs either experimentally or naturally infected with Chlamydiaceae.

This study evaluated the influence of chlamydial infections on lung function in conventionally raised pigs. Eight pigs aged 39-44 days were included in an aerogeneous challenge model (4 were exposed to Chlamydia suis; 4 served as controls). Nineteen pigs aged 5-27 weeks without clinical symptoms (but partly PCR-positive for chlamydial species) were examined over 6 months. For lung function testing, impulse oscillometry was used. In total, all 27 pigs underwent 465 lung function tests. Variables of ventilation (respiratory rate, tidal volume, minute volume), respiratory impedance (expressed as resistance and reactance within the frequency range 3-15 Hz), and model derived resistance of proximal and distal airways were measured. Experimental exposure to C. suis significantly affected lung function. Early distal airway obstruction (3-5 days after infection) was followed by an obstruction of proximal airways (7 days after infection). The breathing pattern was significantly changed (decreased tidal volume; increased respiratory rate). In symptom-free pigs having a naturally acquired presence of different chlamydial species in the respiratory system, no deterioration in lung function could be determined up to the age of 6 months. In conclusion, the consequences of respiratory chlamydial infections appear to vary from clinical inapparence to severe respiratory distress.

Airway Resistance↗
PubMed2004

Immunoblotting, ELISA and culture evidence for Chlamydiaceae in sows on 258 Belgian farms.

The prevalence of Chlamydiaceae infections on 258 closed pig breeding farms in Belgium was examined. For this purpose, 258 farms were randomly selected in the provinces West-Vlaanderen (44%), Oost-Vlaanderen (20%), Antwerpen (10%) and Vlaams-Brabant (6%). Of all farms examined, 96.5% were positive for Chlamydia-specific antibodies in ELISA and most were moderately to strongly positive. ELISA results revealed only 9 (3.5%) sero-negative farms. None of the ELISA negative sera reacted in immunoblotting. Only 212 of 249 ELISA positive sera reacted positive in immunoblotting. Additionally, 23 autopsy samples were examined by isolation in Vero cells. The major outer membrane sequence of the one isolate obtained showed 98.6% amino acid homology to the one of Chlamydophila psittaci strain CP3, formerly isolated from a pigeon. Present observations indicate that chlamydial infections are nearly endemic in the Belgian pig population and that Belgian pigs can become infected with C. psittaci. Nevertheless, the role and significance of Chlamydiaceae as pathogens in pigs remain unsolved and require further investigation.

Amino Acid Sequence↗
PubMed2006

Relative importance of CD4+ and CD8+ T cells in the resolution of Chlamydophila abortus primary infection in mice.

The role of the specific cellular immune response is well established in Chlamydiaceae infections, but the importance of each T-cell subset seems to be species-dependent. This study was designed to clarify the role of T-cell subsets in the response to Chlamydophila abortus primary infection. C57BL/6 mice were depleted of CD4+ or CD8+, or both, by monoclonal antibody injections and subsequently infected with C. abortus. Mice were killed at intervals and samples were collected for bacteriological and histopathological analysis. Also carried out were spleen cell culture, cytokine quantification, immunolabelling for C. abortus antigen, and a TUNEL assay for apoptosis. CD8+ T cell-depleted mice all died within 12 days of C. abortus infection, while no mortality was observed in the other groups; surprisingly, CD4+ T cell-depleted mice showed lower morbidity (expressed as weight loss) than did a non-depleted (control) group. CD8+ T cell-depleted mice also differed from the other groups in showing a significantly higher chlamydial burden in the liver. CD8+ T cell-depleted mice also had a higher number of apoptotic cells in hepatic inflammatory foci and showed exacerbated IFN-gamma production by spleen cells after specific stimulation. Simultaneous depletion of both T-cell subpopulations led to a chronic infection, but not to early mortality. It is concluded that CD8+ T cells may play a role in the regulatory control of the CD4+ T-cell response and may have a direct cytotoxic or IFN-gamma-mediated effect on infected cells.

Animals↗
PubMed1977

[Study of lysosomal enzymes in chick embryo fibroblasts infected with microorganisms of family Halprowiaceae (Chlamydiaceae)].

It is shown that infection of chick embryo fibroblasts with agents of paratrachoma and meningopneumonia Halprowiaceae (Chlamydiaceae) causes a sharp decrease of the activities of lysosomal enzymes, e.g. acidic alpha-glucosidase, beta-glucuronidase, beta-galactosidase, alpha-mannosidase, acid phosphatase, etc. The activity of cytosol enzymes (neutral alpha-glucosidase, amylo-1,6-glucosidase) does not change, however. A decrease in the activities of lysosomal enzymes in infected fibroblasts occurs some time later after inoculation and is due to a release of lysosomal enzymes from the fibroblasts into the culture medium, without loss of cell integrity. No changes in the activity of lysosomal enzymes in fibroblasts and culture medium is observed in the case of inoculation of cells with a killed agents, as well as after contact of cells with a suspension of normal chick embryo yolk sacs. The release of lysosomal enzymes from halprowiae-infected chick embryo fibroblasts probably occurs by the exocytosis.

Acid Phosphatase↗
PubMed2002

[Chlamydial diseases of domestic animals--zoonotic potential of the agents and diagnostic issues].

The role of chlamydiae as agents of a number of important animal and human diseases is still the subject of intensive research. Recently, a proposal for taxonomic reclassification of this group of obligate intracellular bacteria was published, which was based on a large amount of new data on genetic relatedness. According to this proposal, the family Chlamydiaceae now comprises two genera (Chlamydia and Chlamydophila) with 9 largely host-related species. The previously accepted classification scheme had distinguished 4 species within the genus Chlamydia. The most important animal chlamydiosis with zoonotic character is psittacosis, a systemic disease in psittacine birds of acute, protracted, chronic or subclinical manifestation. The analogous infection in domestic and wild fowl is known as ornithosis. Avian strains of C. psittaci (new classification: Chlamydophila psittaci) can also infect humans, the symptoms being mainly unspecific and influenza-like, but severe pneumonia, endocarditis and encephalitis are also known. The main group of persons facing an elevated risk of infection includes those having frequent contact with domestic and companion birds at work or in their spare time. In Germany, the annual average of notified cases is approximately 100. Cases of transmission to humans were repeatedly reported in connection with enzootic abortion in sheep (causative agent: C. psittaci or Chlamydophila abortus, respectively). Various chlamydial species occur as pathogens and commensals as well in cattle, pigs, horses, and cats. The assessment of the actual epidemiological importance is, however, often difficult because of their almost ubiquitous spread. Likewise, those strains of C. pneumoniae (new classification: Chlamydophila pneumoniae) found in several animal species can not yet be assessed for pathogenic properties. The possibilities for diagnostic detection of chlamydiae have considerably improved following the introduction of molecular methods, particularly the polymerase chain reaction (PCR), which permits direct identification from clinical specimens and differentiation of species.

Animals↗
PubMed2007

Lack of microbial DNA in tissue specimens of patients with abdominal aortic aneurysms and positive Chlamydiales serology.

In a case-control study that included a total of 98 patients and 83 controls, the possible link between various pathogens and abdominal aortic aneurysms was investigated. For 68 patients with abdominal aortic aneurysm and age-matched controls, no differences were detected in the levels of immunoglobulin (Ig)A and IgG Chlamydiaceae and Chlamydophila pneumoniae antibodies. Patients with IgA titers positive for Chlamydophila pneumoniae showed progressive disease (defined as an annual increase of the aneurysm diameter of > or = 0.5 cm) more frequently than patients with negative IgA titers (p = 0.046). Polymerase chain reactions performed to detect DNA for Chlamydophila pneumoniae, Chlamydia trachomatis, Chlamydophila psittaci, human cytomegalovirus, Borrelia burgdorferi and Helicobacter pylori in tissue specimens of 30 patients and 15 controls were negative. In summary, Chlamydophila pneumoniae may contribute to aortic aneurysm disease progression, but DNA of this and other pathogens was not found in patients' specimens.

Aged↗
PubMed2005

Mixed infections in vitro with different Chlamydiaceae strains and a cell culture adapted porcine epidemic diarrhea virus.

Assuming a synergistic or additive effect of Chlamydiaceae in coexistence with other enteropathogenic agents, the viral/bacterial interaction between a cell culture adapted porcine epidemic diarrhea virus (ca-PEDV) and different Chlamydiaceae strains was studied in vitro. Vero cells were dually infected with ca-PEDV and one of the three chlamydial strains Chlamydia trachomatis S45, Chlamydophila abortus S26/3 or Chlamydophila pecorum 1710S. Three experimental protocols were designed varying the inoculation sequence. Cell layers were first inoculated with Chlamydiaceae and 20 h later with ca-PEDV in protocol one. In protocol two, both agents were administered concurrently, whereas in protocol three, ca-PEDV was applied 20 h in advance of the Chlamydiaceae. Immunofluorescence techniques, immunohistochemical (IH) staining and electron microscopy were subsequently employed to investigate the cell layers. Using indirect immunofluorescence (IF) labeling, all mixed infections revealed dually infected cells, however, only incidentally and in low numbers. Characteristically, ca-PEDV syncytia with one or more chlamydial inclusions were detected but dually infected single cells were absent. Some syncytial cells contained enlarged C. abortus or C. pecorum inclusions with abnormally large developmental forms. In comparison with simultaneously conducted monoinfections, larger chlamydial inclusions were observed in dually infected cell layers. Experiments with C. trachomatis showed significantly increased numbers of chlamydial inclusions in dually infected cell layers compared to monoinfected ones. These findings indicate an influence of ca-PEDV on the chlamydial developmental cycle and in the case of C. trachomatis, a positive effect on chlamydial colonization in mixed infections.

Animals↗
PubMed2003

Infections with the chlamydia-like microorganism Simkania negevensis, a possible emerging pathogen.

Although evidence for the existence of numerous chlamydia-like microorganisms has been discovered in both environmental samples and clinical specimens, very few have been grown in vitro, and little is known of their pathogenic potential. Of all such organisms, Simkania negevensis is probably the most extensively studied. This review summarizes current knowledge about this intracellular bacterium, focusing especially on human infections.

Chlamydiaceae Infections↗
PubMed1997

[Detection of Chlamydia trachomatis and Ureaplasma urealyticum from aborted tissues by polymerase chain reaction technique].

OBJECTIVE: To study the prevalence of Chlamydia trachomatis (CT) and Ureaplasma urealyticum (UU) infection in spontaneous abortion patients. METHODS: CT and UU in aborted tissues were determined by polymerase chain reaction (PCR) technique in 45 spontaneous abortion patients (abortion group) and 25 artificial abortion cases (control group). RESULTS: The detective rate of CT and UU was 42.2% and 33.3% respectively in the abortion group. As compared with the control group significant difference (P < 0.01, P < 0.025) was shown. The detection rate of mixed CT and UU is 8.9%. CONCLUSION: CT and UU are important infection factors which may cause spontaneous abortion. PCR examination of the aborted tissue can submit an accurate, rapid microorganic diagnosis of CT and (or) UU infection.

Abortion, Spontaneous↗
PubMed2001

Treatment practices for chlamydial infection in New Zealand.

AIMS: To identify prescribing and treatment practices for chlamydial infection in New Zealand. METHODS: Postal survey to doctors and nurses at all sexual health, family planning, student and youth health centres, and randomly selected general practitioners. RESULTS: There was considerable variation in treatment regimes used for chlamydial infection with few respondents treating in accordance with international guidelines regarding dose, frequency, and duration of treatment. Doxycycline (88.4%) was most commonly used to treat uncomplicated chlamydial infection in non-pregnant patients. Most respondents (70.2%) stipulated doxycycline for longer durations than the seven day regimen international guidelines recommend, with doxycycline 100 mg twice a day for ten days most frequently specified. Among the 259 respondents who would treat pregnant women with erythromycin, 51 different treatment regimens were specified, and 51.7% recorded regimens less than that recommended by international guidelines. When treating a patient presumptively, the majority of respondents tested for chlamydial infection. In contrast to other respondents, sexual health clinic staff rarely provide patients with a prescription for a patient's partner without seeing the partner. CONCLUSIONS: Standardised treatment guidelines are required for patients diagnosed with chlamydial infection. Guidelines should include recommendations for the treatment of partners, and encourage the laboratory confirmation of diagnosis.

Anti-Bacterial Agents↗
PubMedDate not supplied

Prevalence and epidemiologic correlates of Chlamydia trachomatis in rural and urban populations.

In two rural and two urban family planning clinics in central Pennsylvania, the authors screened 889 women making routine visits for Chlamydia trachomatis using the Chlamydiazyme immunoassay method (Abbott Laboratories; North Chicago, IL). C. trachomatis antigens were detected in 11.2% of the women; they found no differences in prevalence between rural and urban clinics. Among 21 clinical characteristics and seven risk factors, younger age (younger than 25), oral contraceptive use, gonococcal infection, mucopurulent exudate, abnormal vaginal discharge, and cervical ectropion were associated with chlamydial infection. Logistic regression revealed that age alone was independently associated with infection. The authors found that screening criteria derived from other epidemiologic studies generally did not predict the presence of C. trachomatis in the present sample. In a follow-up study performed at least one year later, 169 patients were re-screened; 47 tested positive and 122 negatives for C. trachomatis. Overall, 11.8% were infected, which was 12.4% of those who originally tested negative and 10.6% of those who originally tested positive.

Chlamydia trachomatis↗
PubMedDate not supplied

Comparison of chlamydial culture with Chlamydiazyme assay during erythromycin PCE treatment of Chlamydia genital infections.

We compared chlamydial culture with the chlamydial antigen detection enzyme immunoassay system (Chlamydiazyme, Abbott Diagnostic Products; Abbott Park, IL) during treatment of Chlamydia genital infections. Participants received 333 mg of erythromycin PCE (Abbott Laboratories; Abbott Park, IL) 3 times per day for 7 days. On days 0, 3, 7, and 14, chlamydial cultures were positive in 30/30 (100%), 5/29 (17.2%), 0/27, and 0/25 participants, respectively. Concurrent Chlamydiazyme assays were positive in 30/30 (100%), 11/30 (37%), 1/28 (4%), and 0/25 participants. Twenty-eight of 28 persons who received erythromycin PCE for at least 3 days had negative test results for both chlamydial culture and Chlamydiazyme at their last clinic visit. Chlamydiazyme assay tended to remain positive longer than chlamydial culture during treatment, but 7 days after therapy was completed, no Chlamydia trachomatis antigens were detectable by this assay. Erythromycin PCE was well tolerated and rapidly eliminated Chlamydia genital infections in 83% of persons showing negative cultures by the third day of therapy.

Antigens, Bacterial↗
PubMed2005

Exposure to Chlamydia pneumoniae infection and progression of age-related macular degeneration.

Recent studies have found an association between exposure to Chlamydia pneumoniae infection and risk of age-related macular degeneration (AMD). To assess a potential risk of AMD progression posed by exposure to C. pneumoniae, the authors reexamined Australian residents in 2001-2002 who were aged 51-89 years with early AMD at baseline (1992-1995). Examination included macular photography and an enzyme-linked immunosorbent assay to determine antibody titers to the elementary bodies from C. pneumoniae AR39. AMD progression was assessed quantitatively, using both coarse and fine progression steps following an international classification for AMD grading, and also qualitatively, by side-by-side comparison of baseline and follow-up macular photographs. Serologic data were available for 246 of 254 (97%) subjects. AMD progression was associated with a higher antibody titer. After adjustment for age, smoking, family history of AMD, history of cardiovascular diseases, and source study, the subjects in the upper tertiles of antibody titers were 2.1 (95% confidence interval: 0.92, 4.69), 2.6 (95% confidence interval: 1.24, 5.41), and 3.0 (95% confidence interval: 1.46, 6.37) times more at risk of progression than those in the lowest tertile, using three definitions of progression, respectively. The fact that seroreactivity to C. pneumoniae was independently associated with the risk of AMD progression suggests that C. pneumoniae infection may be an additional risk factor for AMD progression.

Aged↗