Biology:Intracellular parasite
Intracellular parasites are microparasites that are capable of growing and reproducing inside the cells of a host.[citation needed]
Types of parasites
There are two main types of intracellular parasites: Facultative and Obligate.[1]
Facultative intracellular parasites are capable of living and reproducing in or outside of host cells. Obligate intracellular parasites, on the other hand, need a host cell to live and reproduce. Many of these types of cells require specialized host types, and invasion of host cells occurs in different ways.[1]
Facultative
Facultative intracellular parasites are capable of living and reproducing either inside or outside cells.
Bacterial examples include:
- Bartonella henselae[2]
- Francisella tularensis
- Listeria monocytogenes[3]
- Salmonella Typhi[4]
- Brucella
- Legionella
- Mycobacterium
- Nocardia
- Neisseria
- Rhodococcus equi[5]
- Yersinia
- Staphylococcus aureus[6]
- Mycobacterium tuberculosis (within the macrophages)[7]
Fungal examples include:
Obligate
File:Parasite140105-fig3 Toxoplasmosis in a bar-shouldered dove - TEM of 2 tachyzoites.tif Obligate intracellular parasites cannot reproduce outside their host cell, meaning that the parasite's reproduction is entirely reliant on intracellular resources.
Obligate intracellular parasites of humans include:
- Viruses
- Certain bacteria, including:
- Chlamydia, and closely related species.[11]
- Rickettsia
- Coxiella
- Certain species of Mycobacterium such as Mycobacterium leprae, that survive in phagocytes
- Anaplasma phagocytophilum[lower-alpha 2][12]
- Certain protozoa, including:
- Apicomplexans (Plasmodium spp., Toxoplasma gondii and Cryptosporidium parvum[13])
- Trypanosomatids (Leishmania spp. and Trypanosoma cruzi)
- Certain fungi
The mitochondria in eukaryotic cells may also have originally been such parasites, but ended up forming a mutualistic relationship (endosymbiotic theory).[15]
Study of obligate pathogens is difficult because they cannot usually be reproduced outside the host. However, in 2009 scientists reported a technique allowing the Q-fever pathogen Coxiella burnetii to grow in an axenic culture and suggested the technique may be useful for study of other pathogens.[16]
Exceptions
Polypodium is a metazoan intracellular parasite, distinct from most if not all other intracellular parasites for this reason.[citation needed]
Invasion
When an intracellular parasite goes to enter a host cell, it is particular about the type of host cell. This is because most intracellular parasites are able to infect only a few different cell types.[17] The entrance of these host cells will differ between intracellular parasites. Not all intracellular parasites will enter a cell the same way. Some will work with specific components in or on the host cell, an example being Trypanosoma cruzi. This parasite will attach itself to the host cell while increasing the intracellular calcium, which in turn disrupts the actin at the site of attachment, causing the host cell to create a lysosomal-barrier around the disruption. The parasite will take advantage of this membrane and produce a vacuole in the host cell. Other intracellular parasites have developed different ways to enter a host cell that do not require a specific component or action from within the host cell. An example is intracellular parasites using a method called gliding motility. This is the use of an actin-myosin motor that is connected to the intracellular parasites' cytoskeleton.[17]
Nutrition
The majority of intracellular parasites must keep host cells alive as long as possible while they are reproducing and growing. In order to grow, they need nutrients that might be scarce in their free form in the cell. To study the mechanism that intracellular parasites use to obtain nutrients, Legionella pneumophila, a facultative intracellular parasite, has been used as a model. It is known that Legionella pneumophila obtains nutrients by promoting host proteasomal degradation. Self-degradation of host proteins into amino acids provides the parasite with its primary carbon and energy source.[18]
Susceptibility
People with T cell deficiencies are particularly susceptible to intracellular pathogens.[19]
See also
Explanatory notes
References
- ↑ 1.0 1.1 Leon-Sicairos, Nidia; Reyes-Cortes, Ruth; Guadrón-Llanos, Alma M.; Madueña-Molina, Jesús; Leon-Sicairos, Claudia; Canizalez-Román, Adrian (2015). "Strategies of Intracellular Pathogens for Obtaining Iron from the Environment" (in en). BioMed Research International 2015: 1–17. doi:10.1155/2015/476534. ISSN 2314-6133.
- ↑ "Bartonella henselae". http://www.vetmed.auburn.edu/wp-content/uploads/2015/03/Bartonella-henselae.pdf.
- ↑ Dramsi, Shaynoor; Cossart, Pascale (2002-03-18). "Listeriolysin O". The Journal of Cell Biology 156 (6): 943–946. doi:10.1083/jcb.200202121. ISSN 0021-9525. PMID 11901162.
- ↑ Jantsch, J.; Chikkaballi, D.; Hensel, M. (2011). "Cellular aspects of immunity to intracellular Salmonella enterica". Immunological Reviews 240 (1): 185–195. doi:10.1111/j.1600-065X.2010.00981.x. PMID 21349094.
- ↑ Kelly, B. G.; Wall, D. M.; Boland, C. A.; Meijer, W. G. (2002). "Isocitrate lyase of the facultative intracellular pathogen Rhodococcus equi". Microbiology 148 (Pt 3): 793–798. doi:10.1099/00221287-148-3-793. PMID 11882714.
- ↑ Bravo-Santano (2018). "Intracellular Staphylococcus aureus Modulates Host Central Carbon Metabolism To Activate Autophagy". American Society for Microbiology 3 (4): e00374–18. doi:10.1128/mSphere.00374-18. PMID 30089650.
- ↑ Daffé, M.; Etienne, G. (June 1999). "The capsule of Mycobacterium tuberculosis and its implications for pathogenicity" (in en). Tubercle and Lung Disease 79 (3): 153–169. doi:10.1054/tuld.1998.0200. https://linkinghub.elsevier.com/retrieve/pii/S0962847998902003.
- ↑ "Intracellular parasitism by Histoplasma capsulatum: fungal virulence and calcium dependence". Science 290 (5495): 1368–72. November 2000. doi:10.1126/science.290.5495.1368. PMID 11082066. Bibcode: 2000Sci...290.1368S.
- ↑ Alvarez, M.; Burns, T.; Luo, Y.; Pirofski, L. A.; Casadevall, A. (2009). "The outcome of Cryptococcus neoformans intracellular pathogenesis in human monocytes". BMC Microbiology 9: 51. doi:10.1186/1471-2180-9-51. PMID 19265539.
- ↑ Sterkel, Alana K.; Mettelman, Robert; Wüthrich, Marcel; Klein, Bruce S. (2015-02-15). "The unappreciated intracellular lifestyle of Blastomyces dermatitidis". Journal of Immunology 194 (4): 1796–1805. doi:10.4049/jimmunol.1303089. ISSN 1550-6606. PMID 25589071.
- ↑ "Obligate intracellular bacterial parasites of acanthamoebae related to Chlamydia spp". Applied and Environmental Microbiology 63 (1): 115–21. January 1997. doi:10.1128/AEM.63.1.115-121.1997. PMID 8979345.
- ↑ Foley, Janet E.; Nieto, Nathan C.; Barbet, Anthony; Foley, Patrick (2009-12-15). "Antigen diversity in the parasitic bacterium Anaplasma phagocytophilum arises from selectively-represented, spatially clustered functional pseudogenes". PLOS ONE 4 (12): e8265. doi:10.1371/journal.pone.0008265. ISSN 1932-6203. PMID 20016821.
- ↑ Deng, M.; Lancto, C. A.; Abrahamsen, M. S. (2004). "Cryptosporidium parvum regulation of human epithelial cell gene expression". International Journal for Parasitology 34 (1): 73–82. doi:10.1016/j.ijpara.2003.10.001. PMID 14711592.
- ↑ David Anthony Burns, ed (2010). Rook's Textbook of Dermatology. Vol. 4 (8th ed.). Chichester: Wiley-Blackwell. p. 28. ISBN 978-1-4051-6169-5.
- ↑ Lynn Sagan (1967). "On the origin of mitosing cells". J Theor Biol 14 (3): 255–274. doi:10.1016/0022-5193(67)90079-3. PMID 11541392.
- ↑ "Host cell-free growth of the Q fever bacterium Coxiella burnetii". Proceedings of the National Academy of Sciences USA 106 (11): 4430–4. March 17, 2009. doi:10.1073/pnas.0812074106. PMID 19246385. Bibcode: 2009PNAS..106.4430O.
- ↑ 17.0 17.1 Leirião, Patrícia; Rodrigues, Cristina D; Albuquerque, Sónia S; Mota, Maria M (December 2004). "Survival of protozoan intracellular parasites in host cells" (in en). EMBO Reports 5 (12): 1142–1147. doi:10.1038/sj.embor.7400299. ISSN 1469-221X. PMID 15577928.
- ↑ Price, C. T. D; Al-Quadan, T; Santic, M; Rosenshine, I; Abu Kwaik, Y (2011). "Host Proteasomal Degradation Generates Amino Acids Essential for Intracellular Bacterial Growth". Science 334 (6062): 1553–7. doi:10.1126/science.1212868. PMID 22096100. Bibcode: 2011Sci...334.1553P.
- ↑ Bannister, Barbara A.; Gillespie, Stephen H.; Jones, Jane (2006). "Chapter 22". Infection: Microbiology and Management. Malden, MA: Wiley-Blackwell. p. 432. ISBN 1-4051-2665-5.
Original source: https://en.wikipedia.org/wiki/Intracellular parasite.
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