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Query: UMLS:C0032285 (pneumonia)
 54,520 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Chlamydiae are obligate intracellular parasites, bacteria with a peculiar biology. They belong to the genus Chlamydia which includes two species: C. psittaci and C. trachomatis. A wide range of hosts, including birds, mammals and man can be infected by chlamydiae. The diseases chlamydiae can produce include psittacosis, lymphogranuloma venereum, trachoma, inclusion conjunctivitis, urethritis, cervicitis, pelvic inflammatory disease, and neonatal pneumonia. The diagnosis of chlamydial infection may be made by visualization of the organism in direct smears, isolation of the agent in cell culture, or by demonstrating a significant rise in antibody titer. Chlamydial infection may be treated with tetracycline, erythromycin, or sulfonamides.
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PMID:Human chlamydial infections. 689 17

Systemic infections with Chlamydia trachomatis are known to occur with the agents of lymphogranuloma venereum but are not generally recognized to occur with the trachoma and inclusion conjunctivitis (TRIC) agents, i.e., immunotypes A-K. The clinical spectrum of TRIC agent infections has expanded, however, and now includes deep-seated genital infections such as epididymitis and salpingitis, as well as infections in neonates. Endocarditis, pneumonia in adults, otitis media, choroiditis and erythema nodosum are unusual manifestations of C. trachomatis infections that may be seen. Meningoencephalitis, chronic palmoplantar pustulosis, and pituriasis rosea also might be associated with C. trachomatis infection. Finally, lymphogranuloma venereum may have systemic manifestations, and Chlamydia psittaci infections may be characterized by extrapulmonary involvement.
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PMID:Unusual manifestations of Chlamydia trachomatis infections. 695 8

Antisera from inbred mice (C57BL and C3H) improve the specificity of the microimmunofluorescence test. We used this method in the serotyping of 6 strains of Chlamydia psittaci of differing origin. Inspite of relatively marked cross-reactions it was possible to distinguish 3 groups: - the first group consisted of 2 strains of avian origin and the LGV strain 33L, - the second group consisted of 2 strains responsible for enzootic abortion in ewes, - in the third group, only 1 strain was found and this belonged to meningo-pneumonitis group. The results suggests than C. psittaci has a complex antigenic structure than does C. trachomatis.
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PMID:[Serotyping of "Chlamydia psittaci" by microimmunofluorescence test (author's transl)]. 702 May 25

A mouse model for studying infections due to Chlamydia trachomatis is described. Pneumonitis was produced by intranasal inoculation of four trachoma and one lymphogranuloma venereum strains. The infection was confirmed by cell culture isolation of the organisms from the lung, detection of serum antibody and delayed hypersensitivity, and the observation of inclusions in the interstitial cells of the lung by light and electron microscopy. This study indicates that mice may serve as a useful nonprimate animal model for the study of the pathogenesis and immunology of C. trachomatis infection.
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PMID:A mouse model of Chlamydia trachomatis pneumonitis. 736 76

Over a two year period, we prospectively studied 110 adult patients with Community Acquired Pneumonia (CAP) who presented to the Black Lion Hospital, Addis Ababa, Ethiopia. Pneumococcal infection was diagnosed in 41% by the detection of pneumococcal antigen in sputum and other biologic fluids; in 72% by Gram stain of Lung Aspirate (LA) and in 67.5% by Gram stain of sputum. Blood and Lung Aspirate culture grew Streptococcus Pneumoniae in 4 cases (6%), Staphylococcus Aureus in 4 (6%), Enterobacteriacae in 3(5%), Pseudomonas, Klebsiella Pneumoniae and Strep. Viridans in one case each. Other non-bacterial causes included Mycoplasma Pneumoniae in 4 (4%) Influenza A in 4 (4%), Influenza B in 3 (3%) and Psittacosis/LGV in a 4 (4%). There was no case of Legionnaires disease. 39% had taken treatment before coming to hospital. The mortality was 11%. The study showed that antibiotic treatment during the preceding 36 hours did not affect the outcome of the Gram stain.
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PMID:The etiology of community acquired pneumonia in adults in Addis Ababa. 784 Nov 1

Chlamydiae are among the most successful bacterial pathogens, and there are few branches of medicine on which chlamydial infection and its sequelae do not impinge. Chlamydia trachomatis is responsible for many million cases of blindness, pelvic inflammatory disease, urethritis, epididymitis, infertility and ectopic pregnancy annually; it also causes lymphogranuloma venereum, reactive arthritis, ophthalmia neonatorum and infantile pneumonia. C. pneumoniae is among the most common causes of community-acquired pneumonia, and recent evidence suggests that it may play a part in the pathogenesis of coronary heart disease. C. psittaci is a highly prevalent zoonotic infection with a wide host range. It is of great economic importance, and causes sporadic but sometimes devastating disease in humans. Most chlamydial infections are subclinical, but even if the initial illness is mild there may be serious long-term sequelae. It is therefore important to identify and treat chlamydial infections in their early stages, but diagnosis usually depends on laboratory tests. Recent trials have shown that single doses of the long-acting macrolide azithromycin are effective in the treatment of genital and ocular C. trachomatis infection, but longer courses of antimicrobials remain the mainstay of treatment for C. pneumoniae and C. psittaci infections.
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PMID:Chlamydial infections. 791

In Addis Ababa, Ethiopia, purified chlamydial antigens were used in a micro-immunofluorescence (micro-I) test to detect type-specific antibodies against various chlamydial species in blood samples from 1846 women attending family planning, prenatal, and postnatal clinics. The antigens were for Chlamydia trachomatis A-C (CTA-C), Chlamydia trachomatis D-K (CTD-K), Lymphogranuloma venereum (LGV 1-3), and C. pneumonia (CPn). The researchers considered sera with antibodies to CTA-C, CTD-K, LGV 1-3, and CPn independently or in combination as evidence of overall exposure to chlamydial species (OEC) and those to CTD-K and LGV 1-3 as evidence of exposure to genital chlamydial pathogens (GENCI). They considered sera with IgM titre of 1/8 or more, or IgG titre of 1/64 or more to CTD-K and LGV 1-3 alone or at a similar level with antibodies to CTA-C and CPn as evidence of active genital chlamydial infection (AGCI). 84% were categorized as OEC. 60% were categorized as GENCI. 42% were categorized as AGCI. The prevalence of chlamydial infection was greatest in family planning clients and lowest in pregnant women (OECD: 88% vs. 78%, p = 0.004; GENCI: 63% vs. 54%, p 0.02; and AGCI: 46% vs. 31%) (p 0.01). The geometric mean of the titre was also highest in family planning clients and lowest in pregnant women (85% vs. 58%). The most significant factor for chlamydial infection was being married and having first coitus before age 13 (OEC: 88% vs. 75% for first coitus at 18 years; p 0.001). Other risk factors included low income (p 0.005), more than 5 sexual partners (p 0.01), bar-girl occupation (p 0.001), and Amhara and Oromo ethnic groups (p 0.001). 50% of all women had clinical evidence of past or present infection in the urethra, fallopian tubes, and/or bartholin glands. Women with pelvic inflammatory disease (PID) were more likely to have chlamydial infection than those with no infection in the urethra, fallopian tubes, or bartholin glands (OEC: 95% vs.83%; GENCI: 86% vs. 58%; AGCI: 72% vs. 38%) (p 0.001). PID was also associated with gonorrhea.
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PMID:Chlamydial infection in a population of Ethiopian women attending obstetric, gynaecological and mother and child health clinics. 886 79

An outbreak of ornithosis with 8 cases of ornithosis pneumonia and 2 lethal complications was investigated in workers in a poultry farm and processing plant and a comparative seroepidemiological study of antigen responses was performed in 3 collectives: No. I: n = 82/87 workers in the processing plant, where the outbreak occurred; No. II: n = 83 workers in a chicken slaughter-house; No. III: n = 82 as matched-pair group to collective No. I with the same age and sex, but without occupational risk. The test systems were: genus specific complement fixation reaction (CFR), Ipazyme commercial slide kit containing LGV antigen and a type-specific microimmunofluorescence (MIF) technique with antigens binding C. psittaci, pneumonia and trachomatis IgA, IgG and IgM. 57/82 (71.9%) workers in group No. I were chlamydial antibody-positive, whereas only 22/82 of the population Nr. III--control group (odds ratio 6.2/3.2-12.3 p < or = 0.05). 16/83 (19.3%) of the workers in the chicken slaughterhouse had antibodies against chlamydia group antigens. 30/82 of the collective No. I had serological evidence of a recent or current infection with higher antibody titres in CFR and IPAZYME-Test and/or antibody response against IgA and IgM (MIF). 43.3% of the latter could be serologically detected as specific infections with C. psittaci. 10 of 18 (55%) workers employed in the recent 3 months had serological signs of an acute infection. There was no association between the point of contact with the poultry (live hang areas, slaughtery, evisceration, cooling carcasses) and the prevalence of antibody response. The possible routes of infection, inhalation of dried excretions or aerosols and via hand-to-mouth contacts are discussed. In specimens of cloacal swabs and faeces of the ducks chlamydiae could be found although the animals were asymptomatic. The results of this study demonstrate that in poultry plants, where ducks and other poultry living in an aqueous habitat are slaughtered and processed, a high risk of C. psittaci infection (70.2%) and ornithosis morbidity (25%) with a lethality of 8.3% can exist. Since the eradication of C. psittaci in poultry does not seem to be possible at the moment, preventive measures e.g. gloves, masks, information and medical examinations of the workers must be implemented in those slaughterhouses and plants where C. psittaci is suspected or common.
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PMID:[Ornithosis--studies in correlation with an outbreak]. 1066 40

Sequences of the major outer membrane protein (MOMP) gene (ompA) and the outer membrane complex B protein gene (omcB) from Chlamydia trachomatis, Chlamydia pneumoniae, and Chlamydia psittaci were analyzed for evidence of intragenic recombination and for linkage equilibrium. The Sawyer runs test, compatibility matrices, and index of association analyses provided substantial evidence that there has been a history of intragenic recombination at ompA including one instance of interspecies recombination between the C. trachomatis mouse pneumonitis strain and the C. pneumoniae horse N16 strain. Although none of these methods detected intragenic recombination within omcB, differences in divergence reported in earlier studies suggested that there has been intergenic recombination involving omcB, and the analyses presented in this study are consistent with this. For C. trachomatis, index-of-association analyses suggested a higher degree of recombination for C class than for B class strains and a higher degree of recombination in the downstream half of ompA. In concordance with these findings, many significant breakpoints were found in variable segments 3 and 4 of MOMP for the recombinant strains D/B120, G/UW-57, E/Bour, and LGV-98 identified in this study. We provide examples of how genetic diversity generated by repeated recombination in these regions may be associated with evasion of immune surveillance, serovar-specific differences in tissue tropism, and persistence.
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PMID:Recombination in the ompA gene but not the omcB gene of Chlamydia contributes to serovar-specific differences in tissue tropism, immune surveillance, and persistence of the organism. 1156

Infection by a number of Chlamydia species leads to resistance of the host cell to apoptosis, followed by induction of host-cell death. In a population of infected cells that displays protection against staurosporine-induced apoptosis among the adherent cells, we find that cells that had been recovered from the supernatant share characteristics of both apoptosis and necrosis, as assayed by the propidium iodide (PI)-annexin V double-labeling technique. Cell death was observed in both an epithelial cell line and primary fibroblasts, although the primary cells had a higher propensity to die through apoptosis than the immortalized cell line. Staurosporine-mediated activation of the pro-apoptotic BCL-2 family member, BAX, was inhibited in the epithelial cell line infected for 32 h with the lymphogranuloma venereum (LGV/L2) but not the murine pneumonitis (MoPn) strain of C. trachomatis, but inhibition of staurosporine-mediated BAX activation disappeared after 48 h of infection with the LGV/L2 strain. Conversely, infection with MoPn (C. muridarum) but not LGV/L2 led to BAX activation after 72 h, as previously reported for shorter (48 h) infection with the guinea pig inclusion conjunctivitis (GPIC) serovar of C. psittaci (C. caviae). These results suggest that the ability to inhibit staurosporine-mediated BAX activation or to activate BAX due to the infection itself may vary as a function of the chlamydial strain. Interestingly, both the epithelial cells and the fibroblasts also released high mobility group box 1 protein (HMGB1) during infection, although much less HMGB1 was released from fibroblasts, consistent with the higher level of apoptosis observed in the primary cells. HMGB1 is released preferentially by necrotic or permeabilized viable cells, but not apoptotic cells. In the extracellular space, HMGB1 promotes inflammation through interaction with specific cell-surface receptors. Higher levels of HMGB1 were also measured in the genital-tract secretions of mice infected vaginally with C. trachomatis, compared to uninfected controls. These results suggest that cells infected with Chlamydia release intracellular factors that may contribute to the inflammatory response observed in vivo.
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PMID:Cell death, BAX activation, and HMGB1 release during infection with Chlamydia. 1548 33


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