Chlamydophila caviae: Difference between revisions

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Current research regarding ''Chlamydophila caviae'' focuses on the infections in guinea pigs, causing ocular disease. This research focuses on the identification and pathogenesis of ''Chlamydial'' infections. Tests are used to determine whether or not the ''Acanthamoebae'' species is present in the guinea pigs’ eyes and possible use as vectors in the Chlamydiae organisms. The following methods were used in this experiment: gross pathology, histology, cytology, immunohistochemistry, PCR, sequencing, DNA sampling, and bacteriological staining. The basic conclusion of this experiment is that ''Chlamydophila caviae'' has a zoonotic potential regarding the guinea pig inclusion conjunctivitis; it is capable of infecting guinea pigs. Also, infection by ''Chlamydophila caviae'' is prevalent mainly in young guinea pigs. (10)
Current research regarding ''Chlamydophila caviae'' focuses on the infections in guinea pigs, causing ocular disease. This  


Another current study investigates a gene derived from ArgR that is encoded in many of the ''Chlamydia'' species. In bacteria, ArgR regulates arginine anabolism and degradation based on intracellular levels. ''Chlamydia'' does not contain arginine synthesis genes. ''Chlamydia'' contains artJ, glnQ and glnP, which encode a transport system for arginine. In ''Chlamydophila pneumoniae'', ArgR binds to operator sequences adjacent to the glnPQ operon. ArgR operators are located upstream of glnPQ in ''Chlamydophila caviae'' and ''Chlamydophila pneumoniae''. Based on this research, some Chlamydiaceae organisms have genetic mechanisms that control the uptake of arginine into the cell. One finding is that ''Chlamydophila trachomatis'' does not have the ability to control the intracellular arginine concentrations. On the other hand, ''Chlamydophila pneumoniae'', ''Chlamydophila psittaci'' and ''Chlamydophila caviae'' have this ability. (11)
research focuses on the identification and pathogenesis of ''Chlamydial'' infections. Tests are used to determine whether or


The following current study is based on the fact that asthma is caused by ''Chlamydophila pneumoniae'' infection. Also, its cell wall inhibits the production of IgE. The IgE response from asthmatics is inhibited by tetracyclines. The goal of this experiment is to examine the ''Chlamydophila pneumoniae'' infection in asthmatics. The production of IgE in mononuclear cells is also a main focus in this experiment. Based on this research, ''Chlamydophila pneumoniae'' causes a switch from Th1 to Th2 in asthmatics. Therefore, ''Chlamydophila pneumoniae'' modulates IgE in asthmatics. (12)
not the ''Acanthamoebae'' species is present in the guinea pigs’ eyes and possible use as vectors in the Chlamydiae organisms.
 
The following methods were used in this experiment: gross pathology, histology, cytology, immunohistochemistry, PCR,
 
sequencing, DNA sampling, and bacteriological staining. The basic conclusion of this experiment is that ''Chlamydophila
 
caviae'' has a zoonotic potential regarding the guinea pig inclusion conjunctivitis; it is capable of infecting guinea pigs.
 
Also, infection by ''Chlamydophila caviae'' is prevalent mainly in young guinea pigs. (10)
 
Another current study investigates a gene derived from ArgR that is encoded in many of the ''Chlamydia'' species. In bacteria,
 
ArgR regulates arginine anabolism and degradation based on intracellular levels. ''Chlamydia'' does not contain arginine
 
synthesis genes. ''Chlamydia'' contains artJ, glnQ and glnP, which encode a transport system for arginine. In ''Chlamydophila
 
pneumoniae'', ArgR binds to operator sequences adjacent to the glnPQ operon. ArgR operators are located upstream of glnPQ
 
in ''Chlamydophila caviae'' and ''Chlamydophila pneumoniae''. Based on this research, some Chlamydiaceae organisms have
 
genetic mechanisms that control the uptake of arginine into the cell. One finding is that ''Chlamydophila trachomatis'' does
 
not have the ability to control the intracellular arginine concentrations. On the other hand, ''Chlamydophila
 
pneumoniae'', ''Chlamydophila psittaci'' and ''Chlamydophila caviae'' have this ability. (11)
 
The following current study is based on the fact that asthma is caused by ''Chlamydophila pneumoniae'' infection. Also, its  
 
cell wall inhibits the production of IgE. The IgE response from asthmatics is inhibited by tetracyclines. The goal of this  
 
experiment is to examine the ''Chlamydophila pneumoniae'' infection in asthmatics. The production of IgE in mononuclear cells  
 
is also a main focus in this experiment. Based on this research, ''Chlamydophila pneumoniae'' causes a switch from Th1 to Th2  
 
in asthmatics. Therefore, ''Chlamydophila pneumoniae'' modulates IgE in asthmatics. (12)





Revision as of 18:24, 5 June 2007

A Microbial Biorealm page on the genus Chlamydophila caviae



Classification

Higher order taxa

Domain: Bacteria; Phylum: Chlamydiae; Order: Chlamydiales; Family: Chlamydiaceae; Genus: Chlamydophila; Species: caviae (1)


Species

Chlamydophila caviae


Description and significance

Chlamydophila caviae from the University of Alberta (3)


Chlamydia trachomatis, closely related to Chlamydophila caviae, infecting the Hela cells
   Chlamydia trachomatis, closely related to Chlamydophila caviae, infecting eukaryotic cells from Yale University School of Medicine (4)

Chlamydophila caviae is a rod-shaped organism that causes inclusion conjunctivitis in guinea pigs; inflammation of the

eyelid is a result of infection. (2) The diameter of this Chlamydiae organism is approximately 0.25 to 0.8 micrometers long.

It was isolated from infected guinea pigs. (5) Chlamydophila caviae is a Gram-negative strain (5) with an outer membrane

that lacks peptidoglycan. (6) These organisms are intracellular parasites that inhabit eukaryotic cells. (2) Chlamydophila

caviae rely on their hosts for energy and nutrients; (5) they receive nucleotides, lipids, and amino acids from their hosts.

(7)


Genome structure

In the Chlamydophila caviae GPIC genome, there is one circular chromosome and one plasmid with an unknown function. The

chromosome is 1,173,390 base pairs long and it has a 39.2 percent GC content. The chromosome codes for 998 proteins and 41

RNAs. The plasmid, pCpGP1, is 7,966 base pairs long. The plasmid has a 33.7 percent GC content and it codes for seven

proteins. (2) In the entire genome, there are a total of 1061 genes. Thirty-eight of these genes code for tRNAs and three

genes code for rRNAs. There are 462,922 total GC base pairs, 3 rRNA genes and 1020 genes for proteins. (8)


Cell structure and metabolism

The metabolism of Chlamydophila caviae is simple compared to most bacteria. The organisms of Chlamydiae contain OmpA and

OmpB porins and do not contain siderophores for iron transport. The organisms contain dnaK and groE, genes induced by stress.

In Chlamydiae organisms, the enzymes: citrate synthase, aconitase, and isocitrase dehydrogenase are missing from the Krebs

Cycle. The surface of the elementary bodies is hydrophobic and negatively charged. (7) Chlamydia trachomatis is capable of

producing energy by glycolysis, but it is missing hexokinase and fructose 1,6 bisphosphate aldolase. (6)

Little is known about the specific metabolism of Chlamydophila caviae. Its close relative, Chlamydophila psittaci does

not have cytochrome and flavoprotein carriers in its electron transport chain. Generally, it relies on the host cell for ATP,

(9) but it can produce some ATP from glycolysis. (5) Chlamydophila psittaci produces RNA, DNA, proteins, lipids, glycogen,

amino acids and coenzymes. It has the cellular machinery for the electron transport chain, substrate-level phosphorylation,

and oxidative phosphorylation. (9)

Chlamydia trachomatis contains genes for amino acid transporters and several genes for amino acid biosynthesis. It also

contains TrpA, TrpB, TrpC, enzymes for the biosynthesis of tryptophan and a TrpR aporepressor. Chlamydia trachomatis can

synthesize long chain fatty acids. (5)


Ecology

Two organisms that are close relatives of Chlamydophila caviae, Chlamydophila pneumoniae and Chlamydia

trachomatis, cause disease in humans. Chlamydophila pneumoniae is the agent of pneumonia and asthma. Every year,

approximately ninety-million people in the world are infected with Chlamydia trachomatis. The number of infections

by Chlamydia trachomatis is second only to papillomavirus. Also, it is the major cause of sexually transmitted disease and

pelvic inflammatory disease. Chlamydia trachomatis is the agent of trachoma, which causes ocular disease. This infection

is common among children and it is one of the leading cases of blindness. Trachoma is common in India, the Middle East, Africa

and Latin America. (5)


Pathology

Chlamydophila caviae causes ocular disease and conjunctivitis in guinea pigs. (10) The following cycle describes the

infection and replication of Chlamydophila caviae and Chlamydia organisms within its hosts. The two major components

of this cycle are the elementary body and the reticulate body. The elementary body infects the cell and the reticulate body

initiates metabolic processes inside the cell. During the infection cycle, the elementary bodies attach to the surface of the

epithelial cells. The elementary bodies enter the host via endocytosis and fuse with each other to form inclusions in the

infected cell. Inside the host cell, the elementary bodies are converted into the reticulate bodies and replicate by binary

fission. The reticulate bodies insert proteins into the inclusion membrane in order to obtain nutrients from the host cell.

The projections from the surface of Chlamydia enter the inclusion membrane of the host cell. Chlamydia do not have to

leave the vacuole in order to obtain nutrients from their eukaryotic hosts. Then, the reticulate bodies are converted into

elementary bodies before leaving the host cells. (5)

In addition, Chlamydophila psittaci, a close relative of Chlamydophila caviae, infects birds and causes infection of

the respiratory system. This disease is rare in the United States and in many cases, it is undiagnosed. Psittacne birds are

usually infected, along with parrots and parakeets. In bird factories, humans can be infected via the respiratory tract.

Common symptoms of infection by Chlamydophila psittaci are coughing, fevers, and headaches; this disease is often fatal.

(7)


Application to Biotechnology

Chlamydia organisms produce proteins that may have potential applications to biotechnology. MOMP, which is located in the

elementary bodies and the reticulate bodies, is produced by the OmpA gene. In the elementary bodies, MOMP is linked by

disulfide bonds. MOMP is a porin in the outer membrane of Chlamydia organisms. Also, OmcA and OmcB are located in

elementary bodies. They are proteins in the outer membrane and they contain cysteine. These proteins may be utilized for

cellular processes. (7)


Current Research

Current research regarding Chlamydophila caviae focuses on the infections in guinea pigs, causing ocular disease. This

research focuses on the identification and pathogenesis of Chlamydial infections. Tests are used to determine whether or

not the Acanthamoebae species is present in the guinea pigs’ eyes and possible use as vectors in the Chlamydiae organisms.

The following methods were used in this experiment: gross pathology, histology, cytology, immunohistochemistry, PCR,

sequencing, DNA sampling, and bacteriological staining. The basic conclusion of this experiment is that Chlamydophila

caviae has a zoonotic potential regarding the guinea pig inclusion conjunctivitis; it is capable of infecting guinea pigs.

Also, infection by Chlamydophila caviae is prevalent mainly in young guinea pigs. (10)

Another current study investigates a gene derived from ArgR that is encoded in many of the Chlamydia species. In bacteria,

ArgR regulates arginine anabolism and degradation based on intracellular levels. Chlamydia does not contain arginine

synthesis genes. Chlamydia contains artJ, glnQ and glnP, which encode a transport system for arginine. In Chlamydophila

pneumoniae, ArgR binds to operator sequences adjacent to the glnPQ operon. ArgR operators are located upstream of glnPQ

in Chlamydophila caviae and Chlamydophila pneumoniae. Based on this research, some Chlamydiaceae organisms have

genetic mechanisms that control the uptake of arginine into the cell. One finding is that Chlamydophila trachomatis does

not have the ability to control the intracellular arginine concentrations. On the other hand, Chlamydophila

pneumoniae, Chlamydophila psittaci and Chlamydophila caviae have this ability. (11)

The following current study is based on the fact that asthma is caused by Chlamydophila pneumoniae infection. Also, its

cell wall inhibits the production of IgE. The IgE response from asthmatics is inhibited by tetracyclines. The goal of this

experiment is to examine the Chlamydophila pneumoniae infection in asthmatics. The production of IgE in mononuclear cells

is also a main focus in this experiment. Based on this research, Chlamydophila pneumoniae causes a switch from Th1 to Th2

in asthmatics. Therefore, Chlamydophila pneumoniae modulates IgE in asthmatics. (12)


References

1. KEGG. Chlamydophila caviae GPIC. 2007. http://www.genome.jp/kegg-bin/show_organism?org=cca

2. Entrez Genome Project. 2007. Chlamydophila caviae GPIC. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=genomeprj&cmd=Retrieve&dopt=Overview&list_uids=228

3. Wishart, D. Chlamydophila caviae. BacMap Genome Atlas. University of Alberta. http://wishart.biology.ualberta.ca/BacMap/cgi/getSpeciesCard.cgi?accession=NC_003361&ref=index_2.html

4. Singla, M., and B. Bikram. “Infectivity Assays for Chlamydia Trachomatis.” The Internet Journal of Microbiology. 2006. Volume 2. http://www.ispub.com/ostia/index.php?xmlFilePath=journals/ijmb/vol2n2/chlamydia.xml

5. Engleberg, N.C., DiRita, V., and T.S. Dermody. Schaechter’s Mechanisms of Microbial Disease. 4th Ed. Lippincott Williams & Wilkins. 2007. Chapter 27. p. 284-291.

6. Barton, L.L. Structural and Functional Relationships in Prokaryotes. Springer. 2005. p. 96, 596.

7. Stephens, R.S. Chlamydia: Intracellular Biology, Pathogenesis and Immunity. American Society for Microbiology. 1999. p. 16-19, 54, 78-79, 81, 89, 104-108, 140, 143-144.

8. TIGR Comprehensive Microbial Resource. Chlamydophila caviae GPIC Genome Page. http://cmr.tigr.org/tigr-scripts/CMR/GenomePage.cgi?org=gcp

9. Prescott, L.M., Harley, J.P. and D.A. Klein. Microbiology. 6th Ed. McGraw-Hill. 2005. Chapter 21. p. 464-466.

10. Lutz- Wohlgroth, L., Becker, A., Brugnera, E., Huat, Z.L., Zimmermann, D., Grimm, F., Haessig, M., Greub, G., Kaps, S., Spiess, B., Pospischil, A., and L. Vaughan. “Chlamydiales in guinea-pigs and their zoonotic potential.” J Vet Med A Physiology Pathology Clinical Medicine. 2006. Volume 53 p.185-193. http://www.blackwell-synergy.com/links/doi/10.1111/j.1439-0442.2006.00819.x

11. Schaumburg, C.S., and M. Tan. “Arginine-Dependent Gene Regulation via the ArgR Repressor Is Species Specific in Chlamydia.” J. Bacteriology. 2006. Volume 188. p. 919-927. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=16428395

12. Kohlhoff, S.A., Joks, R., Kamath, T., Kutlin, A., Smith-Norowitz, T., Nowakowski, M., Bluth, M., Durkin, H., and M.R. Hammerschlag. “Chlamydophila pneumoniae (Cpn) Mediated IgE Production by Peripheral Blood Mononuclear Cells (PBMCs) of Allergic Asthmatics is Suppressed by Doxycycline.” Journal of Allergy and Clinical Immunology. 2007. Volume 119. p. 525. http://linkinghub.elsevier.com/retrieve/pii/S0091674906038255


Edited by Katherine Kaushal, student of Rachel Larsen and Kit Pogliano