Chlamydophila pneumoniae

From MicrobeWiki, the student-edited microbiology resource

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

Chlamydophila pneumoniae, courtesy of Prof. A. Matsumoto

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 it's 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.

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

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

8. Chlamydia Pneumoniae Help and Treatment

9. Center of Disease Control and Prevention


Edited by student of Rachel Larsen and Kit Pogliano