Chlamydophila pneumoniae

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A Microbial Biorealm page on the genus Chlamydophila pneumoniae

Classification

Higher order taxa

Kingdom: Bacteria; Phylum: Chlamydiae; Order: Chlamydiales; Genus: Chlamydophila; Species: C. pneumoniae; [NCBI]

Species

NCBI: Taxonomy

Chlamydophila pneumoniae

Description and Significance

Chlamydophila pneumoniae is a species of rod-shaped, Gram-negative bacteria that is known to be a major cause of pneumonia, asthma, bronchitis, respiratory infection, coronary heart disease, and atherosclerosis in humans. It is an airborne bacteria and about 50% of adults in the United States have evidence of previous infection by the age of 20. Similar to viruses, Chlamydophila pneumoniae is a parasitic organism that cannot reproduce outside of the host cell and is therefore dependent on the health of the host cell for survival.

Before more advanced research tools that compared DNA and antigenic material were invented, there was only one genus under the family Chlamydiaceae. That genus was Chlamydia. However, after finding very different DNA and antigenic material, another genus was introduced into the family: Chlamydophila which means "Clamydia-like". Thus, the previously named Chlamydia pneumoniae was renamed Chlamydophila pneumoniae [6].

Genome Structure

The gene sequence of Chlamydophila pneumoniae CWL029, the strain most common in the United States, has been fully sequenced, as with many other strains, in 1999. The genome contains 1,230,230 base pairs of circular DNA. There are 1,052 protein genes and 43 RNA genes. There are no plasmids that have been identified as of yet with this species [1,5].

Cell Structure and Metabolism

Chlamydophila pneumoniae exists in a stationary, non-infectious state inbetween hosts known as a elementary body (EB). Although the elementary body is not infectious, it has the ability to withstand environmental stresses until it reaches a new host where it transforms into a reticulate body (RB). The bacteria undergoes aerobic respiration. Chlamydophila pneumoniae has an incubation period from 7-21 days within its host and divides every 2-3 hours [7].

Ecology

Chlamydophila pneumoniae is known and is seen in human hosts all around the world. Many studies have been conducted in the United States and Japan. It was shown that these two isolated strains of Chlamydophila pneumoniae, Chlamydophila pneumoniae J138 (Japan) and Chlamydophila pneumoniae CWL029 (US) are very similar to each other in overall function, with only a difference in about 3,600 base pairs. The infection rate between genders have been equal and there is no bias toward one gender or the other.

Pathology

The elementary form of the bacteria is transferred via small water droplets into another host's lungs where it is phagtocytosed into cells. Once the elementary body is taken in, it transforms into the reticulate body, where it replicates itself within the cell. With numerous copies of itself within the cell, the reticulate body reverts back to its elementary form, lyses the cell, and begins the cycle of infection again. Being a mesophile, the optimum temperature of replication of this bacteria is 37 degrees Celsius.

Chlamydophila pneumoniae is also known to infect reptiles such as snakes, iguanas, frogs, turtles, and mammals such as koalas.

Symptoms include dry cough, fatigue, pain the side of the chest, fever, loss of appetite, and aches.

Application to Biotechnology

Although Chlamydophila pneumoniae is not known to produce any useful enzymes or compounds directly, because of its widespread infection world-wide, antibiotics against this bacteria have been produced indirectly. However, these antibiotics are only shown to be useful in the very early stages of infection. Three types of antibiotics that are commonly used are azithromycin, doxycycline, and clarithromycin.

Current Research

There are two observations in which multiple sclerosis (MS)is known to cause disease. The first observation sudden death of oligodendrites by the degredation of the myelin sheath. Another observation is that many bacteria, including Chlamydophila pneumoniae, have been closely associated with MS. The mechanism of Chlamydophila pneumoniae in the human body is discussed [7].

There is a hypothesis that carotid disease symptomatology is closely related to the presence of Chlamydophila pneumoniae. Carotid disease was tested alongside the presence of Chlamydophila pneumoniae to see if they are in correlation with each other. It turns out that Cerebrovascular disease is strongly related to not only the presence of Chlamydophila pneumoniae and a factor called the TNF-alpha factor [8].

It has been widely accepted that the presence of Chlamydophila pneumoniae in the cerebrospinal fluid (CSF) is very closely related to multiple sclerosis (MS). In order to test and reproof this thought, scientists ran PCR checks and DNA extraction methods on those with multiple sclerosis. After these checks, it was indeed proved that the high concentration of Chlamydophila pneumoniae in the CSF is associated with MS [9].

References

1. Shirai, M., Hirakawa, H., Kimoto, M., Tabuchi, M., Kishi, F., Ouchi, K., Shiba, T., Ishii, K., Hattori, M., Kuhara, S., and Nakazawa, T. "Comparison of whole genome sequences of Chlamydia pneumoniae J138 from Japan and CWL029 from USA." Nucleic Acids Res.(2000) 28:2311-2314.

2. Everett, K.D., Bush, R.M., Andersen, A.A. "Emended description of the order Chlamydiales, proposal of Parachlamydiaceae fam. nov. and Simkaniaceae fam. nov., each containing one monotypic genus, revised taxonomy of the family Chlamydiaceae, including a new genus and five new species, and standards for the identification of organisms." Int. J. Syst. Bacteriol. (1999) 49:415-440..

3. Cunningham, A. F., Johnston, S. L., Julious, S. A., Lampe, F. C. Ward, M. E. Chronic Chlamydia pneumoniae infection and asthma exacerbations in children. European Respiratory Journal. (1998) 11:345 - 349.

4. Fukushi, H., and Hirai, K. "Restriction fragment length polymorphisms of rRNA as genetic markers to differentiate Chlamydia spp." Int. J. Syst. Bacteriol. (1993) 43:613-617.

5. Gaydos, C.A., Palmer, L., Quinn, T.C., Falkow, S., and Eiden, J.J. "Phylogenetic relationship of Chlamydia pneumoniae to Chlamydia psittaci and Chlamydia trachomatis as determined by analysis of 16S ribosomal DNA sequences." Int. J. Syst. Bacteriol. (1993) 43:610-612.

6. Grayston, J T., Kuo, C. C., Campbell, L. A. & Wang, S. P. Chlamydia pneumoniae sp-nov for Chlamydia sp strain TWAR. International Journal of Systematic Bacteriology (1989) 39:88 - 90.

7. Stratton CW, Wheldon DB. Multiple sclerosis: an infectious syndrome involving Chlamydophila pneumoniae.. Trends Microbiol. (2006) 14(11):474-9.

8. Stratton CW, Sriram S. Association of Chlamydia pneumoniae with central nervous system disease.. Microbes Infect. (2003) 5(13):1249-1253.

9. Sriram S, Yao S, Mitchell WM, Calibresi P, Stratton CW, Ikejima H, Yamamoto Y. Comparative study of the presence of Chlamydia pneumoniae in cerebrospinal fluid from clinically definite and monosympomatic muliple sclerosis patinets. Clinical and Diagnostic Laboratory Immunology )2003) 9:1332-1337.

10. The Comprehensive Reference and Education Site to Chlamydia and the Chlamydiae

11. Chlamydia Pneumoniae Help and Treatment

12. Center of Disease Control and Prevention

Edited by icho of Rachel Larsen and Kit Pogliano