Chlamydia pneumoniae

Taxobox
color = lightgrey
name = "Chlamydia pneumoniae"
regnum = Bacteria
phylum = Chlamydiae
ordo = Chlamydiales
familia = Chlamydiaceae
genus = "Chlamydia"
species = "C. pneumoniae"

"Chlamydia pneumoniae" is a species of chlamydiae bacteria that infects humans and is a major cause of pneumonia. "Chlamydia pneumoniae" has a complex life cycle and must infect another cell in order to reproduce and thus is classified as an obligate intracellular pathogen. In addition to its role in pneumonia, there is evidence associating "Chlamydia pneumoniae" with atherosclerosis and with asthma. The full genome sequence for "Chlamydia pneumoniae" was published in 1999.

Chlamydia pneumoniae also infects and causes disease in Koalas, emerald tree boa (Corallus caninus), iguanas, chameleons, frogs, and turtles.

The first known case of infection with C. pneumoniae was a case of sinusitis in Taiwan.

This atypical bacterium commonly causes pharyngitis, bronchitis and atypical pneumonia [Lang, B. R., "Chlamydia pneumonia" as a differential diagnosis? Follow-up to a case report on progressive pneumonitis in an adolescent, "Patient Care", Sept. 15, 1991] mainly in elderly and debilitated patients but in healthy adults also. [Little, Linda, Elusive pneumonia strain frustrates many clinicians, "Medical Tribune", p. 6, September 19, 1991]

Life cycle and method of infection

"Chlamydia pneumoniae" is a small bacterium (0.2 to 1 micrometer) that undergoes several transformations during its life cycle. It exists as an elementary body (EB) in between hosts. The EB is not biologically active but is resistant to environmental stresses and can survive outside of a host for a limited time. The EB travels from an infected person to the lungs of a non-infected person in small droplets and is responsible for infection. Once in the lungs, the EB is taken up by cells in a pouch called an endosome by a process called phagocytosis. However, the EB is not destroyed by fusion with lysosomes as is typical for phagocytosed material. Instead, it transforms into a reticulate body and begins to replicate within the endosome. The reticulate bodies must utilize some of the host's cellular machinery to complete its replication. The reticulate bodies then convert back to elementary bodies and are released back into the lung, often after causing the death of the host cell. The EBs are thereafter able to infect new cells, either in the same organism or in a new host. Thus, the life cycle of "Chlamydia pneumoniae" is divided between the elementary body which is able to infect new hosts but can not replicate and the reticulate body which replicates but is not able to cause new infection.

Pneumonia caused by Chlamydia pneumoniae

"Chlamydia pneumoniae" is a common cause of pneumonia around the world. "Chlamydia pneumoniae" is typically acquired by otherwise healthy people and is a form of community-acquired pneumonia. Because treatment and diagnosis are different from historically recognized causes such as "Streptococcus pneumoniae", pneumonia caused by "Chlamydia pneumoniae" is categorized as an "atypical pneumonia."

Symptoms and diagnosis

Symptoms of infection with "Chlamydia pneumoniae" are indistinguishable from other causes of pneumonia. These include cough, fever, and difficulties breathing. "Chlamydia pneumoniae" more often causes pharyngitis, laryngitis, and sinusitis than other causes of pneumonia; however, because many other causes of pneumonia results in these symptoms, differentiation is not possible. Likewise, a physical examination by a health provider does not typically provide information which allows for a definite diagnosis.

Diagnosis of "Chlamydia pneumoniae" may be confounded by prior infections with this microorganism. Examination of sputum or the secretions of the respiratory tract may reveal signs of the bacteria. Otherwise, examination of the blood may reveal antibodies against the bacteria. Interpretation may require a period of six weeks in order to reanalyze the antibodies and to determine whether the infection was new or old. Examination of the blood may also show proteins (antigens) from "Chlamydia pneumoniae", either through direct fluorescent antibody testing, enzyme-linked immunosorbent assay (ELISA), or polymerase chain reaction (PCR).

Chest x-rays of lungs infected with "Chlamydia pneumoniae" often show a small patch of increased shadow (opacity). However, many different patterns are common and there is no appearance which allows for a specific diagnosis.

Treatment and prognosis

Typically, treatment for pneumonia is begun before the causative microorganism is identified. This empiric therapy includes an antibiotic active against the atypical bacteria, including "Chlamydia pneumoniae". The most common type of antibiotic used is a macrolide such as azithromycin or clarithromycin. If testing reveals that "Chlamydia pneumoniae" is the causative agent, therapy may be switched to doxycycline, which is slightly more effective against the bacteria. Sometimes a quinolone antibiotic such as levofloxacin may be started empirically. This group is not as effective against "Chlamydia pneumoniae". Treatment is typically continued for ten to fourteen days for known infections.

Prognosis of pneumonia caused by "Chlamydia pneumoniae" is excellent. Hospitalization is uncommon, complications are rare, and most people have no residual deficits. In fact, "Chlamydia pneumoniae" is a common cause of "walking pneumonia", so named because most people are able to continue to walk and participate in reduced activity during infection.

Epidemiology and prevention

"Chlamydia pneumoniae" affects all age groups and is most common among the 60-79 year old age group. Reinfection is common after a short period of immunity. The incidence is one case out of one thousand per year and causes ten percent of community-acquired pneumonias treated without hospitalization.Fact|date=February 2007 As of 2005, there are no vaccines or other ways to prevent infection other than good hygiene.

Other illnesses caused by "Chlamydia pneumoniae"

In addition to pneumonia, "Chlamydia pneumoniae" less commonly causes several other illnesses. Among these are meningoencephalitis (infection and inflammation of the brain and spinal cord), arthritis, myocarditis (inflammation of the heart), and Guillain-Barré syndrome (inflammation of the nerves). It has also been associated with dozens of other conditions, such as Alzheimer's disease, Fibromyalgia, Chronic Fatigue Syndrome, Prostatitis, and many others.

Links between "Chlamydia pneumoniae" and chronic inflammatory diseases

In addition to acute infections already covered, "Chlamydia pneumoniae" has been implicated in several chronic diseases. There is evidence that the onset of asthma, a chronic inflammatory disease of the lungs, is associated with infection with "Chlamydia pneumoniae". Fact|date=February 2007 Some patients have had amazing recoveries from lifelong asthma as the result of being prescribed anti-chlamydial antibiotics.Fact|date=February 2007 However, not all asthma results from infection with chlamydia pneumoniae, and research is ongoing.

Links between infection with "Chlamydia pneumoniae" heart attacks (myocardial infarction) and atherosclerosis have also been found. [cite journal |author=Blasi F, Denti F, Erba M, "et al" |title=Detection of Chlamydia pneumoniae but not Helicobacter pylori in atherosclerotic plaques of aortic aneurysms |journal=J. Clin. Microbiol. |volume=34 |issue=11 |pages=2766–9 |year=1996 |month=Nov |pmid=8897180 |pmc=229401 |doi= |url=http://jcm.asm.org/cgi/pmidlookup?view=long&pmid=8897180] In fact, "Chlamydia pneumoniae" has been found within plaques in the walls of coronary arteries supplying the heart. [cite journal |author=Ramirez JA |title=Isolation of Chlamydia pneumoniae from the coronary artery of a patient with coronary atherosclerosis. The Chlamydia pneumoniae/Atherosclerosis Study Group |journal=Ann. Intern. Med. |volume=125 |issue=12 |pages=979–82 |year=1996 |month=Dec |pmid=8967709 |doi= |url=http://www.annals.org/cgi/pmidlookup?view=long&pmid=8967709] [cite journal |author=Jackson LA, Campbell LA, Kuo CC, Rodriguez DI, Lee A, Grayston JT |title=Isolation of Chlamydia pneumoniae from a carotid endarterectomy specimen |journal=J. Infect. Dis. |volume=176 |issue=1 |pages=292–5 |year=1997 |month=Jul |pmid=9207386 |doi= |url=] Antibody levels against "Chlamydia pneumoniae" are also higher in people with heart problems. [cite journal |author=Danesh J, Collins R, Peto R |title=Chronic infections and coronary heart disease: is there a link? |journal=Lancet |volume=350 |issue=9075 |pages=430–6 |year=1997 |pmid=9259669 |doi= 10.1016/S0140-6736(97)03079-1|accessdate=] As of 2005, short-term prescription of anti-chlamydial antibiotics has not been shown to decrease incidence of myocardial infarction. [cite web |url=https://openaccess.leidenuniv.nl/dspace/bitstream/1887/9729/11/01.pdf
publisher= The digital repository of Leiden University
title= Lipids, inflammation and atherosclerosis
author=M Stitzinger |year=2007
accessdate=2007-11-02 |format= pdf|work=|quote= Results of clinical trials investigating anti-chlamydial antibiotics as anaddition to standard therapy in patients with coronary artery disease havebeen inconsistent. Therefore, Andraws et al conducted a meta-analysis of these clinical trials and found that evidence available to datedoes not demonstrate an overall benefit of antibiotic therapy in reducingmortality or cardiovascular events in patients with coronary arterydisease.] Such treatment is experimental, although research from Vanderbilt as early as the mid 1990s found that Chlamydia pneumoniae had a role in many chronic inflammatory diseases Fact|date=February 2007 and that multi-antibiotic protocols could be helpful, or even 'cure' some individuals with conditions such as Chronic Fatigue Syndrome.cite web |url=http://www.fibromyalgiasupport.com/library/showarticle.cfm/id/7938/searchtext/Chlamydia%20pneumoniae/ |title=Chlamydia pneumoniae in Chronic Fatigue Syndrome and Fibromyalgia - An Opinion |accessdate=2008-08-24 |work= |publisher= |date=

Chlamydia pneumoniae has also been found in the cerebrospinal fluid of some patients diagnosed with multiple sclerosis,cite journal |author=Sriram S, Stratton CW, Yao S, "et al" |title=Chlamydia pneumoniae infection of the central nervous system in multiple sclerosis |journal=Ann. Neurol. |volume=46 |issue=1 |pages=6–14 |year=1999 |pmid=10401775 |doi= 10.1002/1531-8249(199907)46:1<6::AID-ANA4>3.0.CO;2-M|accessdate=] a controversial finding, but pilot data suggests that antibiotic treatment of MS results in improvements, sometimes dramatic, in such cases.cite web |url=http://www.davidwheldon.co.uk/ms-treatment1.html |title=Empirical antibacterial treatment of infection with Chlamydophila pneumoniae in Multiple Sclerosis |accessdate=2008-08-08 |work= |publisher= |date= A range of other inflammatory conditions are hypothesized to be linked with infection with chlamydial pneumonaie, including fibromyalgia, chronic fatigue syndrome, intercystial cystitis and prostatitis, as well as many others.cite web |url=http://www.immunesupport.com/healthwatch/sum98/bacterium.cfm |title=Breaking Research Reveals Common Bacterium Chlamydia Pneumoniae may be Culprit in CFIDS, FMS and MS |accessdate=2008-08-01 |work= |publisher= |date=

References

*cite journal |author=Bodetti TJ, Jacobson E, Wan C, "et al" |title=Molecular evidence to support the expansion of the hostrange of Chlamydophila pneumoniae to include reptiles as well as humans, horses, koalas and amphibians |journal=Syst. Appl. Microbiol. |volume=25 |issue=1 |pages=146–52 |year=2002 |month=Apr |pmid=12086181 |doi= 10.1078/0723-2020-00086|url=

*cite journal |author=Cannon CP, Braunwald E, McCabe CH, "et al" |title=Antibiotic treatment of Chlamydia pneumoniae after acute coronary syndrome |journal=N. Engl. J. Med. |volume=352 |issue=16 |pages=1646–54 |year=2005 |month=Apr |pmid=15843667 |doi=10.1056/NEJMoa043528 |url=
*cite journal |author=Hahn DL, Dodge RW, Golubjatnikov R |title=Association of Chlamydia pneumoniae (strain TWAR) infection with wheezing, asthmatic bronchitis, and adult-onset asthma |journal=JAMA |volume=266 |issue=2 |pages=225–30 |year=1991 |month=Jul |pmid=2056624 |doi= 10.1001/jama.266.2.225|url=
*cite journal |author=Jacobson ER, Heard D, Andersen A |title=Identification of Chlamydophila pneumoniae in an emerald tree boa, Corallus caninus |journal=J. Vet. Diagn. Invest. |volume=16 |issue=2 |pages=153–4 |year=2004 |month=Mar |pmid=15053368 |doi= |url=http://www.jvdi.org/cgi/pmidlookup?view=long&pmid=15053368
*cite journal |author=Kalman S, Mitchell W, Marathe R, "et al" |title=Comparative genomes of Chlamydia pneumoniae and C. trachomatis |journal=Nat. Genet. |volume=21 |issue=4 |pages=385–9 |year=1999 |month=Apr |pmid=10192388 |doi=10.1038/7716 |url=
*cite journal |author=Mattson MP |title=Infectious agents and age-related neurodegenerative disorders |journal=Ageing Res. Rev. |volume=3 |issue=1 |pages=105–20 |year=2004 |month=Jan |pmid=15163105 |doi=10.1016/j.arr.2003.08.005 |url=
*cite journal |author=O'Connor S, Taylor C, Campbell LA, Epstein S, Libby P |title=Potential infectious etiologies of atherosclerosis: a multifactorial perspective |journal=Emerging Infect. Dis. |volume=7 |issue=5 |pages=780–8 |year=2001 |pmid=11747688 |doi= |url=http://www.cdc.gov/ncidod/eid/vol7no5/oconnor.htm
*cite journal |author=Storey C, Lusher M, Yates P, Richmond S |title=Evidence for Chlamydia pneumoniae of non-human origin |journal=J. Gen. Microbiol. |volume=139 |issue=11 |pages=2621–6 |year=1993 |month=Nov |pmid=8277245 |doi= |url=
*cite journal |author=Thomas NS, Lusher M, Storey CC, Clarke IN |title=Plasmid diversity in Chlamydia |journal=Microbiology (Reading, Engl.) |volume=143 ( Pt 6) |issue= |pages=1847–54 |year=1997 |month=Jun |pmid=9202459 |doi= |url=http://mic.sgmjournals.org/cgi/pmidlookup?view=reprint&pmid=9202459

External links

* http://cpnhelp.org CPNhelp.org, A Clearinghouse for Information on Treatment of CPn Infections, especially those believed to be associated with chronic and disabling diseases such as MS and Chronic Fatigue Syndrome. Includes dozens of scientific papers, input from physicians who treat CPn infections, links to patents, and a forum to communicate with patients currently going through treatment of CPn infection through multi-antibiotic protocols.
* http://fpnotebook.com/LUN24.htm "Family Practice Notebook" page on Chlamydia pneumoniae

* [http://www.asthmastory.com/a70.asp Abstract by Nancy Humphrey]

*cite journal |author=Kuoppa Y, Boman J, Scott L, Kumlin U, Eriksson I, Allard A |title=Quantitative detection of respiratory Chlamydia pneumoniae infection by real-time PCR |journal=J. Clin. Microbiol. |volume=40 |issue=6 |pages=2273–4 |year=2002 |month=June |pmid=12037108 |pmc=130697 |doi= 10.1128/JCM.40.6.2273-2274.2002|url=http://jcm.asm.org/cgi/pmidlookup?view=long&pmid=12037108

*cite journal |author=Kuo CC, Jackson LA, Campbell LA, Grayston JT |title=Chlamydia pneumoniae (TWAR) |journal=Clin. Microbiol. Rev. |volume=8 |issue=4 |pages=451–61 |year=1995 |month=Oct |pmid=8665464 |pmc=172870 |doi= |url=http://cmr.asm.org/cgi/pmidlookup?view=long&pmid=8665464

*cite journal |author=Barut A, Inal A, Demiröz P, Hacibektaşoğlu A |title= [A new respiratory tract pathogen] |language=Turkish |journal=Mikrobiyol Bul |volume=25 |issue=2 |pages=194–205 |year=1991 |month=Apr |pmid=1745154 |doi= |url=

*cite journal |author=Grayston JT, Kuo CC, Wang SP, Altman J |title=A new Chlamydia psittaci strain, TWAR, isolated in acute respiratory tract infections |journal=N. Engl. J. Med. |volume=315 |issue=3 |pages=161–8 |year=1986 |month=Jul |pmid=3724806 |doi= |url=

*cite journal |author=Falck G, Heyman L, Gnarpe J, Gnarpe H |title=Chlamydia pneumoniae (TWAR): a common agent in acute bronchitis |journal=Scand. J. Infect. Dis. |volume=26 |issue=2 |pages=179–87 |year=1994 |pmid=8036474 |doi= 10.3109/00365549409011782|url=

* [http://www.asthmastory.com/a26.asp AsthmaStory.com]

NewsRx: http://www.newsrx.com/search_results.php?search_term=Respiratory%20%3Ci%3EChlamydia%3C/i%3E&doSearch=Search

Chlamydia Pneumoniae and chronic Diseases:
* http://books.google.com/books?id=kBtbytrAzYwC&pg=PA65&lpg=PA65&dq=%22respiratory+chlamydia%22&source=web&ots=NgK2ltCXvu&sig=xVTvuLkEXT7DfAeh1qUVNpFGvhc#PPP2,M1

Evaluation of PCR, Culture, and Serology for Diagnosis of Chlamydiapneumoniae Respiratory infections
* https://ep.eur.nl/bitstream/1765/8866/1/9666010.pdf

Doctors Treating Outbreak at Units
* http://www.aperfectcause.com/artman/publish/article_2855.asp

IP Opportunities: Novel vaccine for treating chlamydia
* http://www.newcastleinnovation.com.au/Resources/Chlamydia.pdf

Infections and the Cardiovascular System: New Perspectives:
* http://books.google.com/books?id=Dp6wRIuSP-sC&pg=PA159&lpg=PA159&dq=%22respiratory+chlamydia%22&source=web&ots=fex6Tw59dk&sig=Vi5YvNNaWXg1XL_IXpQfdSE84hY#PPA155,M1

Chlamydia Research Group
* http://www.newcastle.edu.au/school/biomedical-science/research/chlamydia.html

Bronchial Chlamydia pneumoniae infection, markers of allergic inflammation and lung function in children.
* http://pt.wkhealth.com/pt/re/pall/abstract.00012984-200110000-00005.htm;jsessionid=HyTRH1dhNThQW2w1fQcNJkkGdSJ2N1Wg5VQ7PGNQh2JP91Hd2H8x!1219373867!181195629!8091!-1