Chlamydophila pneumoniae is a species of Chlamydophila , a obligate intracellular bacteria that infects humans and is a major cause of pneumonia. It is known as Taiwan acute respiratory agent (TWAR) from the names of two indigenous isolates - Taiwan (TW-183) and acute respiratory discharge designated AR-39. Until now, it is known as Chlamydia pneumoniae, and the name is used as an alternative in some sources. In some cases, to avoid confusion, both names are given.
C. pneumoniae has a complex life cycle and must infect other cells to reproduce; thus, are classified as obligat intracellular pathogens. The full genome sequence for C. pneumoniae was published in 1999. It also infects and causes diseases in koalas, emerald tree boas (Corallus caninus ), iguanas, chameleons, frogs, and turtle.
The first known case of infection with C. pneumoniae was a case of conjunctivitis in Taiwan in 1950. There was no known case of C. pneumoniae in human history before 1950. These atypical bacteria were generally causing pharyngitis, bronchitis, coronary artery disease and atypical pneumonia in addition to several other possible diseases.
Video Chlamydophila pneumoniae
Life cycle and infection method
Chlamydophila pneumoniae is a small gram negative bacteria (0.2 to 1? m) that undergoes some transformation during its life cycle. It exists as the basic body (EB) between the inhabitants. EB is not biologically active, but is resistant to environmental stress and can survive outside the host for a limited time. EB travels from an infected person to the lungs of an uninfected person in small droplets and is responsible for infection. Once in the lungs, the EB is taken up by cells in a bag called endosome by a process called phagocytosis. However, the EB is not destroyed by fusion with lysosomes, as is typical for phagocytic agents. Instead, it turns into a reticulate body (RB) and begins to replicate within the endosome. The body of the reticulum must use some host cell metabolism to complete its replication. The reticulate body then converts back to the base body and is released back into the lungs, often after causing the death of the host cell. EB can then infect new cells, either in the same organism or in the new host. Thus, the life cycle of C. pneumoniae is divided between the base body, capable of infecting a new host but is unable to replicate, and the reticular body, which replicates but can not cause new infections.
Maps Chlamydophila pneumoniae
Disease
C. pneumoniae is a common cause of pneumonia worldwide; usually obtained by unhealthy people and is a form of community acquired pneumonia. Treatment and diagnosis differ from historically known causes, such as Streptococcus pneumoniae . Because it is not well-stained with gram, and because bacteria are very different from many other bacteria that cause pneumonia (in earlier days, even as viruses), pneumonia is caused by C pneumoniae is categorized as "atypical pneumonia".
One meta-analysis of serological data comparing previous C i pneumoniae infection in patients with and without lung cancer found results suggesting previous infections were associated with an increased risk of developing lung cancer.
In a study of the relationship between C. pneumoniae infection and atherosclerosis and coronary artery disease, serological tests, direct pathologic analysis of plaque, and in vitro testing showed infection with C pneumoniae is a significant risk factor for the development of atherosclerotic plaque and atherosclerosis. C. pneumoniae infection improves macrophage adherence to endothelial cells in vitro and aortas ex vivo . However, most current studies and data are insufficient and do not determine how often C. pneumoniae is found in atherosclerotic or normal vascular tissue.
C. pneumoniae has also been found in the cerebrospinal fluid of patients diagnosed with multiple sclerosis.
C. pneumoniae infection was first associated with wheeze, asthma bronchitis, and adult onset asthma in 1991. Subsequent studies of bronchoalveolar lavage fluid from pediatric patients with asthma and other severe chronic respiratory diseases have shown that more of 50 percent had evidence of C. pneumoniae with direct organism identification. C. pneumoniae infection triggers acute wheezing, if it becomes chronic then it is diagnosed as asthma. These observations indicate that acute C. pneumoniae infection is capable of causing the manifestations of protean chronic respiratory diseases that cause asthma.
Macrolide antibiotic treatment may increase asthma in a subgroup of patients that remains to be clearly defined. The benefits of macrolides were first suggested in two observational tests and two randomized controlled trials of azithromycin treatment for asthma. One RCT and other macrolide experiments show that the effects of treatment may be greatest in patients with severe refractory asthma. These clinical results correlate with epidemiological evidence that C. pneumoniae is positively associated with asthma severity and laboratory evidence that C. pneumoniae infection creates steroid resistance. The most recent meta-analysis of 12 macrolide RCTs for long-term management of asthma found a significant effect on asthma symptoms, quality of life, hyper bronchial reactivity and peak flow but not FEV1. Evidence from a macrolide RCT of patients with severe and uncontrolled asthma is uncommon in defining the macrolide role in asthma.
Vaccination research
There is currently no vaccine to protect against Chlamydophila pneumoniae . Identification of immunogenic antigens is critical for the development of a potent subunit vaccine against infections of C. pneumoniae. In addition, there is a worldwide general shortage of facilities that can identify/diagnose Chlamydia pneumoniae .
References
External links
- Chlamydia Pneumoniae cpnhelp.org
- Type strain Chlamydophila pneumoniae in Bac Dive - Metadatabase Bacterial Diversity
Source of the article : Wikipedia
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