Chlamydia pneumoniae

Chla·myd·i·a pneu·mo·ni·ae

a species first isolated in 1986 and currently recognized as a common cause of pneumonia, bronchitis, rhinosinusitis, and pharyngitis in both adults and children.
Synonym(s): TWAR

Chlamydia pneumoniae is responsible for about 25% of cases of acute bronchitis and 10% of community-acquired pneumonia. It may also play a role in the genesis of cardiovascular disease and late-onset Alzheimer dementia. Like C. trachomatis and C. psittaci, this organism is an occasional cause of myocarditis and endocarditis. Elevated levels of antibody to C. pneumoniae are found in patients with acute myocardial infarction (MI) and in those showing severe atheroma formation at autopsy significantly more often than in control groups. The organism has been detected by immunocytochemistry, polymerase chain reaction, and electron microscopy in macrophages and smooth muscle cells of atheromatous plaques of the aorta, coronary arteries, and carotid arteries (surgical and autopsy specimens), but not in normal arteries. The incidence of acute infection in MI patients, as detected by throat culture, is higher than in the general public. A retrospective review of medical records of patients with acute MI showed that they were less likely than matched controls to have been treated during the preceding 3 years with tetracycline or quinolone antibiotics, which are active against C. pneumoniae. To date, however, prospective studies have not shown an association between the presence of IgG antibody to C. pneumoniae and an increased risk of atherothrombotic disease. The current body of evidence favors infection with C. pneumoniae as one of several factors capable of initiating changes that culminate in atherosclerosis. Limited studies suggest that antibiotic treatment may reduce the risk of recurrent coronary events, but have not shown benefits in stable coronary artery disease. Antibody to C. pneumoniae is also found in patients with severe hypertension at about twice the incidence rate for the general public, and has been linked statistically to accelerated loss of lung function in patients with asthma. In addition, the organism has been detected in microglia and astroglia of the hippocampus and temporal cortex in patients with late-onset Alzheimer disease with much greater frequency than in normal brains.

Chlamydia pneumoniae

C psittaci TWAR A pathogen that causes pneumonia, asymptomatic RTIs, pharyngitis, otitis media

Chla·myd·o·phil·a pneu·mo·ni·ae

(klă-midō-filă nū-mōnē-ē)
A species that causes pneumonia and upper and lower respiratorydisease. Also called Chlamydia pneumoniae (q.v.), TWAR.

Chla·myd·i·a pneu·mo·ni·ae

(klă-mi'dē-a nū-mō'nē-ē)
A species recognized as a common cause of pneumonia, bronchitis, rhinosinusitis, and pharyngitis.
Synonym(s): TWAR.
References in periodicals archive ?
Chlamydia spp were not detected in wild birds; however, 4 species (Chlamydia psittaci, Chlamydia pecorum, Chlamydia pneumoniae, and Chlamydia gallinacea) were identified among captive birds (Passeriformes, n = 20; Psittaciformes, n = 15; Rheiformes, n = 8; Falconiformes, n = 2; Piciformes, n = 2; Anseriformes, n = 1; Galliformes, n = 1; Strigiformes, n = 1).
Researchers found an index of antibody levels caused by exposure to Chlamydia pneumoniae, Helicobacter pylori, cytomegalovirus, and herpes simplex viruses 1 and 2 was associated with worse cognitive performance, including memory, speed of mental processing, abstract thinking, planning and reasoning ability.
In addition, studies have found evidence of association between periodontal bacteria and increased diabetes risk, as well as links between decreased insulin sensitivity and higher antibody titers to HSV 2 and Chlamydia pneumoniae.
Background & objectives: Association of Chlamydia pneumoniae with atherosclerosis and coronary artery disease is debated.
Recent findings suggest a role for immunologic processes in AMD pathogenesis, including the age-related generation of extracellular deposits inside the Brusch membrane and beneath the retinal pigment epithelium, recruitment of macrophages for clearance of these deposits, complement activation, recruitment of tissue-destructive macrophages, microglial activation and accumulation, and proinflammatory effects of chronic inflammation by Chlamydia pneumoniae.
ALS patients also have other chronic infections, including Human Herpes Virus-6 (HHV-6), Chlamydia pneumoniae, and, as mentioned above, Borrelia burgdorferi but rarely hepatitis virus (Figure 1).
Early research into the role of Chlamydia pneumoniae generated interest in pursuing clinical trials using antibiotics to mitigate the effects of C pneumoniae and other organisms.
Chlamydia pneumoniae - a respiratory bacteria that infects most people at some point in their lives - is linked to the build up of plaque in the artery walls.