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Mycoplasma gallisepticum (MG) is a bacterium belonging to the class Mollicutes and the family Mycoplasmataceae. It is the causative agent of chronic respiratory disease (CRD) in chickens and infectious sinusitis in turkeys, chickens, game birds, pigeons, and passerine birds of all ages. 〔Mercia, Leonard. Storey's Guide to Raising Poultry. 1. North Adams, MA: Storey Publishing, 2001. 272,-73. Print.〕 Mycoplasmosis is the infection of Mycoplasma bacteria. Mycoplasmas have many defining characteristics. Mycoplasma lack cell walls, have highly variable surface proteins and a distinctive plasma membrane, and are the smallest self-replicating prokaryotes. Mycoplasma can cause disease in humans, animals, insects, and plants.〔U.S. Geological Survey (). 1999. Field Manual of Wildlife Diseases: General Field Procedures and Disease of Birds. Biological Resources Division Information and Technology Report 1999–2001.〕 Mycoplasma attach to host epithelial cells, such as in the respiratory tract, which causes cell damage and inflammatory response. There are currently over 100 species of Mycoplasma known. The following have been isolated from wild birds: ''Mycoplasma buteonis'', ''Mycoplasma corogypsi'', ''Mycoplasma falconis'', ''Mycoplasma gypis'', ''Mycoplasma sturni'', and ''Mycoplasma gallisepticum''.〔Thomas, NJ, DB Hunter, CT Atkinson. 2007. Infectious Diseases of Wild Birds. Blackwell Publishing, Ames, Iowa, USA.〕 ''M. gallisepticum'' has the most significant effect on wild birds.〔 ==History== The disease was first described in 1905. It was described as a respiratory disease that was found in domestic poultry. However, it wasn’t for another 50 years that the causative agent, ''Mycoplasma gallisepticum'', was cultivated.〔 In 1980, ''M. gallisepticum'' was isolated from wild turkeys in Colorado, Georgia and California. This was because of the mixture and close contact between the wild turkeys and domestic poultry during feeding time. This led to an increased awareness of the disease and health monitoring protocols in wild turkey restoration programs. These protocols are still being followed today by state wildlife agencies.〔 House finches were introduced into the eastern U.S. from California in the 1940s after being released from the pet trade that became illegal. House finches at the time were called “Hollywood finches”.〔Michigan Department of Natural Resources. 2013. Mycoplasmosis. http://www.michigan.gov/dnr/0,4570,7-153-10370_12150_12220-27089--,00.html. Accessed 20 Oct 2013.〕 In January 1994, the first house finches with symptoms of ''M. gallisepticum'' were observed in the Washington DC area, including part of Maryland and Virginia.〔Cornell Lab of Ornithology. 2013. House Finch Disease.http://www.birds.cornell.edu/hofi/abtdisease.html. Accessed 21 Oct 2013.〕 In the winter of 1994, an epidemic of mycoplasmal conjunctivitis caused by ''M. gallisepticum'' began in house finches.〔 In 1994, efforts were made across North America to collect data on the spread and prevalence of ''M. gallisepticum'' using the House Finch Disease Survey.〔 A few years later the epidemic that started in the mid-Atlantic states spread to the entire eastern population of house finches.〔 The only house finches to have this disease are those introduced to the eastern United States. It is believed that these house finches are less resistant to the disease because they were introduced and were highly inbred. The disease was stopped by the Rocky Mountains.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Mycoplasma gallisepticum」の詳細全文を読む スポンサード リンク
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