Mycoplasma gallisepticum

Last updated

Mycoplasma gallisepticum
Mycoplasma gallisepticum.jpg
Electron micrograph of Mycoplasma gallisepticum, scale bar 140 nm
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Bacteria
Phylum: Mycoplasmatota
Class: Mollicutes
Order: Mycoplasmatales
Family: Mycoplasmataceae
Genus: Mycoplasma
Species:
M. gallisepticum
Binomial name
Mycoplasma gallisepticum
Edward and Kanarek 1960 (Approved Lists 1980)

Mycoplasma gallisepticum (MG) is a bacterium in the class Mollicutes and the family Mycoplasmataceae. It causes chronic respiratory disease (CRD) in chickens and infectious sinusitis in turkeys, chickens, game birds, pigeons, and passerine birds of all ages. [1] [2] Mycoplasma gallisepticum is a significant pathogen in poultry.

Contents

Mycoplasmosis is the disease caused by infection with mycoplasmas. 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. Mycoplasmas can cause disease in humans, animals, insects, and plants. [3] Mycoplasmas attach to host epithelial cells, such as in the respiratory tract, causing cell damage and an inflammatory response. There are currently over 100 species of mycoplasmas known. The following have been isolated from wild birds: Mycoplasma buteonis, Mycoplasma corogypsi, Mycoplasma falconis, Mycoplasma gypis, Mycoplasma sturni, and Mycoplasma gallisepticum. [4] M. gallisepticum has the most significant effect on wild birds. [3]

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. [4]

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. [4]

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. [5] 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. [6] In the winter of 1994, an epidemic of mycoplasmal conjunctivitis caused by M. gallisepticum began in house finches. [4] 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. [6] A few years later the epidemic that started in the mid-Atlantic states spread to the entire eastern population of house finches. [4]

Initially, the only house finches to have this disease were those introduced to the eastern United States. It has been suggested that those house finches were less resistant to the disease because they were introduced beginning with a small population, and were subsequently highly inbred. [7] For a time, the disease appeared to be stopped by the Rocky Mountains, [5] but was found in the Rockies by the early 2000s, and west of the range by 2006. [8] After crossing the Rockies, the disease spread south along the west coast before turning back inland. [9] Research using RFID tags to track a sample of wild finches found an individual bird's likelihood of acquiring or transmitting the infection to be positively correlated with time spent at feeders. [10] [11]

Clinical signs

House finches

Mycoplasma gallisepticum infection in house finches ( Haemorhous mexicanus ) causes conjunctivitis with the symptoms of periocular swelling, swollen eyelids, ocular and nasal discharge, impaired vision, depression, and weight loss. Infected birds may be listless or seem disoriented, present with reckless or limited flight, and a timid reluctance to flee predators or humans. [12] These symptoms cause house finch populations to decline due to increased predation and susceptibility to trauma from impaired vision, [4] as well as from starvation due to infected birds' difficulty feeding themselves. [9] House finch conjunctivitis is most frequent during colder months when birds are using bird feeders and can cause birds to be reluctant to leave the feeders. Birds have been seen rubbing their eyes on branches or on bird feeders, which can help spread the disease. [3]

Chickens

Some major clinical signs of M. gallisepticum in chickens include those of respiratory distress such as coughing, sneezing, slight to marked rales, and difficulty breathing. [13] Swollen eyelids, ocular discharge, and loss of sight are signs and symptoms that are very important for this disease as well. [5] Poor productivity, leg problems, nasal discharge, stunting, inappetence, slow growth, reduced hatchability, reduced chick viability, and abnormal feathers are also some relevant clinical signs of the disease. [14] M. gallisepticum infections in chickens result in relatively mild catarrhal sinusitis, tracheitis, and airsacculitis." [13]

Turkeys

Mycoplasma gallisepticum causes respiratory infection in turkeys which can induce sinusitis, pneumonia, and airsacculitis. With infectious sinusitis, the birds have symptoms of coughing, swollen sinuses, nasal and ocular discharge, tracheal rales, labored breathing, impaired vision, depression and weight loss. The disease can even cause death and found to especially occur if combined with E. coli . Outbreaks in turkeys occur at an early age usually between 8 and 15 weeks and about 90% of birds show signs. [4] With breeding females, there could be a decline in egg production. "Occasionally an encephalitic form is seen in growing birds. A tenovaginitis may also develop and the organism can be found in the oviduct and semen of infected male birds, leading to infection in the egg and eventually of the young poulty." [15]

Other avian species

Other avian species that have been affected by this disease are pigeons, chukar partridges, quail, ducks, geese, pheasants, psittacine birds, and peafowl. Most songbirds are resistant except for the wild house finches and some similar species in North America. [13] Some exotic birds infected by this disease include greater flamingos, wild peregrine falcons in Spain, and yellow-naped Amazon parrots. [16]

Transmission

M. gallisepticum can be transmitted within some poultry eggs, which can come from infected breeders to progeny. Also, M. gallisepticum can be transmitted via infectious aerosols and through contamination of feed, water, and environment as well as human activity on fomites which can come from equipment and shoes. [4] When birds are stressed transmission can occur more rapidly through aerosols and respiratory which spread through the flock. When they are in a flock, transmission occurs by direct and indirect contact from the movement of the birds, people and fomites from infected species. With many outbreaks, the source of the infection in the flock is unknown. Some sources that could possibly cause infection and transmission are cold weather, poor air quality, concurrent infections, and some live virus vaccinations. [13]

Diagnosis

The greatest success in isolating M. gallisepticum has been from tissue swabs from live trapped or newly dead birds. In recent studies, it has been found that generally results obtained from dead birds are more reliable. [17] It is difficult to obtain a sample from frozen carcasses. Tissue swabs are taken from the inner eyelids, sinus, and trachea. Many serology tests can be performed to diagnose M. gallisepticum: serum plate agglutination (SPA) test, hemagglutination inhibition test (HI), or enzyme-linked immunosorbent assay (ELISA). The SPA test is more commonly used because it is the simplest and least expensive. [4] Tests can be performed on serum samples as well as tissue samples. However, it has been stated that serological tests cannot be interpreted without the results to be obtained from the PCR method. It has been found that antibody responses change in the early and advanced stages of the disease and the results vary according to the test method. [17]

Health concerns

Mycoplasma gallisepticum causes respiratory disease and weakens the immune system which makes the bird vulnerable to any disease that they come into contact with. Small bubbles will appear in the corners of the eyes and sinuses will swell up. Once infected, they are carriers for the disease for life. Some birds have good resistance to the disease while others may die; some become ill and recover and others may not show any symptoms at all. There is currently no risk to humans. For domestic animals, there is a high concern and there should be a prevention of any interaction between wild birds and domestic poultry. Wild bird species affected by the disease are infectious and are often found in close contact with domestic species. [4]

Wildlife rehabilitation and treatment

Wildlife rehabilitators should be careful to not misdiagnose M. gallisepticum infection with other diseases with similar clinical signs, such as avian influenza, chlamydiosis, Newcastle disease, infectious bronchitis, head trauma, and avian pox virus. M. gallisepticum can be treated with antibiotics such as tylosin, tetracycline, or oral enrofloxacin with ophthalmic gentamicin. These are given through food, water or injections. Especially tylosin gives good results in the feed. [1] However, treated birds must be kept in captivity and isolation for a long time period because birds may become asymptomatic carriers. At this point, it is very difficult to verify if previously infected birds are still infected with M. gallisepticum. Treatment and release is not wise for disease control in wild populations. [4]

Economic impact

Mycoplasma gallisepticum is believed to cost the worldwide poultry industry over $780 million every year. In the United States it is believed to cost over $120 million on egg production alone. [2] Infection can lead to the culling of an entire flock to prevent further spread. [2]

Since the disease causes reduced feed and growth production, carcass condemnations, and retarded growth in juveniles, serious economic losses have occurred. [4] Also, chickens have been documented to lose about 16 eggs over their laying cycle of 45 weeks. This adds up to be a loss of about $140 million annually in the United States alone. [18]

Related Research Articles

<span class="mw-page-title-main">Psittacosis</span> Infectious disease in humans

Psittacosis—also known as parrot fever, and ornithosis—is a zoonotic infectious disease in humans caused by a bacterium called Chlamydia psittaci and contracted from infected parrots, such as macaws, cockatiels, and budgerigars, and from pigeons, sparrows, ducks, hens, gulls and many other species of birds. The incidence of infection in canaries and finches is believed to be lower than in psittacine birds.

<i>Influenza A virus</i> Species of virus

Influenza A virus (IAV) is the only species of the genus Alphainfluenzavirus of the virus family Orthomyxoviridae. It is a pathogen with strains that infect birds and some mammals, as well as causing seasonal flu in humans. Mammals in which different strains of IAV circulate with sustained transmission are bats, pigs, horses and dogs; other mammals can occasionally become infected.

<span class="mw-page-title-main">Avian influenza</span> Influenza caused by viruses adapted to birds

Avian influenza, also known as avian flu or bird flu, is a disease caused by the influenza A virus, which primarily affects birds but can sometimes affect mammals including humans. Wild aquatic birds are the primary host of the influenza A virus, which is enzootic in many bird populations.

<span class="mw-page-title-main">Virulent Newcastle disease</span> Contagious viral avian disease

Virulent Newcastle disease (VND), formerly exotic Newcastle disease, is a contagious viral avian disease affecting many domestic and wild bird species; it is transmissible to humans. Though it can infect humans, most cases are non-symptomatic; rarely it can cause a mild fever and influenza-like symptoms and/or conjunctivitis in humans. Its effects are most notable in domestic poultry due to their high susceptibility and the potential for severe impacts of an epizootic on the poultry industries. It is endemic to many countries. No treatment for VND is known, but the use of prophylactic vaccines and sanitary measures reduces the likelihood of outbreaks.

<span class="mw-page-title-main">Influenza A virus subtype H5N1</span> Subtype of influenza A virus

Influenza A virus subtype H5N1 (A/H5N1) is a subtype of the influenza A virus, which causes influenza (flu), predominantly in birds. It is enzootic in many bird populations, and also panzootic. A/H5N1 virus can also infect mammals that have been exposed to infected birds; in these cases, symptoms are frequently severe or fatal.

Poultry diseases occur in poultry, which are domesticated birds kept for their meat, eggs or feathers. Poultry species include the chicken, turkey, duck, goose and ostrich.

Avian infectious bronchitis (IB) is an acute and highly contagious respiratory disease of chickens. The disease is caused by avian infectious bronchitis virus (IBV), a coronavirus, and characterized by respiratory signs including gasping, coughing, sneezing, tracheal rales, and nasal discharge. In young chickens, severe respiratory distress may occur. In layers, respiratory distress, nephritis, decrease in egg production, and loss of internal and external egg quality are reported.

Avian coronavirus is a species of virus from the genus Gammacoronavirus that infects birds; since 2018, all gammacoronaviruses which infect birds have been classified as this single species. The strain of avian coronavirus previously known as infectious bronchitis virus (IBV) is the only coronavirus that infects chickens. It causes avian infectious bronchitis, a highly infectious disease that affects the respiratory tract, gut, kidney and reproductive system. IBV affects the performance of both meat-producing and egg-producing chickens and is responsible for substantial economic loss within the poultry industry. The strain of avian coronavirus previously classified as Turkey coronavirus causes gastrointestinal disease in turkeys.

<span class="mw-page-title-main">Global spread of H5N1</span> Spread of bird flu

The global spread of H5N1 influenza in birds is considered a significant pandemic threat. While other H5N1 influenza strains are known, they are significantly different on a genetic level from a highly pathogenic, emergent strain of H5N1, which was able to achieve hitherto unprecedented global spread in 2008. The H5N1 strain is a fast-mutating, highly pathogenic avian influenza virus (HPAI) found in multiple bird species. It is both epizootic and panzootic. Unless otherwise indicated, "H5N1" in this timeline refers to the 2008 highly pathogenic strain of H5N1.

<span class="mw-page-title-main">Transmission and infection of H5N1</span> Spread of an influenza virus

Transmission and infection of H5N1 from infected avian sources to humans has been a concern since the first documented case of human infection in 1997, due to the global spread of H5N1 that constitutes a pandemic threat.

<span class="mw-page-title-main">Influenza A virus subtype H7N7</span> Virus subtype

Influenza A virus subtype H7N7 (A/H7N7) is a subtype of Influenza A virus, a genus of Orthomyxovirus, the viruses responsible for influenza. Highly pathogenic strains (HPAI) and low pathogenic strains (LPAI) exist. H7N7 can infect humans, birds, pigs, seals, and horses in the wild; and has infected mice in laboratory studies. This unusual zoonotic potential represents a pandemic threat.

<span class="mw-page-title-main">Specific-pathogen-free</span> Term for laboratory animals known to be without pathogens

Specific-pathogen-free (SPF) is a term used for laboratory animals that are guaranteed free of particular pathogens. Use of SPF animals ensures that specified diseases do not interfere with an experiment. For example, absence of respiratory pathogens such as influenza is desirable when investigating a drug's effect on lung function.

Avipoxvirus is a genus of viruses within the family Poxviridae. Poxviridae is the family of viruses which cause the afflicted organism to have poxes as a symptom. Poxviruses have generally large genomes, and other such examples include smallpox and monkeypox. Members of the genus Avipoxvirus infect specifically birds. Avipoxviruses are unable to complete their replication cycle in non-avian species. Although it is comparably slow-spreading, Avipoxvirus is known to cause symptoms like pustules full of pus lining the skin and diphtheria-like symptoms. These diphtheria-like symptoms might include diphtheric necrotic membranes lining the mouth and the upper respiratory tract. Like other avian viruses, it can be transmitted through vectors mechanically such as through mosquitoes. There is no evidence that this virus can infect humans.

<span class="mw-page-title-main">Influenza</span> Infectious disease

Influenza, commonly known as "the flu" or just "flu", is an infectious disease caused by influenza viruses. Symptoms range from mild to severe and often include fever, runny nose, sore throat, muscle pain, headache, coughing, and fatigue. These symptoms begin one to four days after exposure to the virus and last for about two to eight days. Diarrhea and vomiting can occur, particularly in children. Influenza may progress to pneumonia from the virus or a subsequent bacterial infection. Other complications include acute respiratory distress syndrome, meningitis, encephalitis, and worsening of pre-existing health problems such as asthma and cardiovascular disease.

<span class="mw-page-title-main">Histomoniasis</span> Medical condition

Histomoniasis is a commercially significant disease of poultry, particularly of chickens and turkeys, due to parasitic infection of a protozoan, Histomonas meleagridis. The protozoan is transmitted to the bird by the nematode parasite Heterakis gallinarum. H. meleagridis resides within the eggs of H. gallinarum, so birds ingest the parasites along with contaminated soil or food. Earthworms can also act as a paratenic host.

Mycoplasma synoviae is a species of bacterium in the genus Mycoplasma. It causes disease in the joints, bones and respiratory system of birds. It is found throughout the world and infection may be referred to as infectious synovitis, avian mycoplasmosis, infectious sinusitis, or mycoplasma arthritis. It is of economic importance because infection can cause a drop in egg production. The disease is most commonly seen in chickens, and transmission occurs both vertically and horizontally.

<span class="mw-page-title-main">Egg drop syndrome</span> Viral disease of birds

Egg drop syndrome '76 is a viral disease that affects birds, notably chickens, ducks, geese and swans. It is characterised by a sudden drop in production of eggs as well as its eggshell quality in apparent healthy laying birds.

Infectious coryza is a serious bacterial disease of chickens that affects the respiratory system, and it is manifested by inflammation of the area below the eye, nasal discharge, and sneezing. The disease is found all over the world, causing high economic losses, which are due to stumping off and reduction of egg production in case of laying chickens. The disease was discovered early 1930s by considering clinical signs.

<i>Avian metaavulavirus 2</i> Species of virus

Avian metaavulavirus 2, formerly Avian paramyxovirus 2, is a species of virus belonging to the family Paramyxoviridae and genus Metaavulavirus. The virus is a negative strand RNA virus containing a monopartite genome. Avian metaavulavirus 2 is one of nine species belonging to the genus Metaavulavirus. The most common serotype of Avulavirinae is serotype 1, the cause of Newcastle disease (ND). Avian metaavulavirus 2 has been known to cause disease, specifically mild respiratory infections in domestic poultry, including turkeys and chickens, and has many economic effects on egg production and poultry industries. The virus was first isolated from a strain in Yucaipa, California in 1956. Since then, other isolates of the virus have been isolated worldwide.

<span class="mw-page-title-main">Airsacculitis</span> Bacterial, fungal or viral inflammatory disease of air sacs in birds.

Airsacculitis, also known as air sacculitis, aerosacculitis, air sac disease, air sac infection, air sac syndrome and simply sac disease, is a common inflammatory condition of air sacs that occurs in birds and is caused by various microbial taxa. Having multiple different causative agents, the condition is widely distributed around the world.

References

  1. 1 2 Mercia, Leonard (2001). Storey's Guide to Raising Poultry. 1. North Adams, MA: Storey Publishing. pp. 272–73.
  2. 1 2 3 Hennigana, Suzanne L.; Jeremy D. Driskellb; Naola Ferguson-Noelc; Richard A. Dluhyd; Yiping Zhaoe; Ralph A. Trippb; Duncan C. Krausea (30 December 2011). "Detection and Differentiation of Avian Mycoplasmas by Surface-Enhanced Raman Spectroscopy Based on a Silver Nanorod Array". Applied and Environmental Microbiology. 78 (6): 1930–1935. doi:10.1128/AEM.07419-11. PMC   3298138 . PMID   22210215.
  3. 1 2 3 U.S. Geological Survey [USGS]. (1999). Field Manual of Wildlife Diseases: General Field Procedures and Disease of Birds. Biological Resources Division Information and Technology Report 1999–2001.
  4. 1 2 3 4 5 6 7 8 9 10 11 12 Thomas, NJ; Hunter, DB and Atkinson, CT (2007). Infectious Diseases of Wild Birds. Blackwell Publishing, Ames, Iowa, USA.
  5. 1 2 3 Michigan Department of Natural Resources. (2013). Mycoplasmosis Archived 2018-02-21 at the Wayback Machine .
  6. 1 2 Cornell Lab of Ornithology. (2013). House Finch Disease Archived 2015-09-23 at the Wayback Machine .
  7. ↑ "House Finch Conjunctivitis". PennState Extension. 3 January 2023. Archived from the original on 24 April 2024. Retrieved 23 April 2024.
  8. ↑ Heisman, Rebecca (11 January 2017). "House Finch Eye Disease: Outbreak, Then Understanding". All About Birds. Cornell Lab of Ornithology. Archived from the original on 16 August 2024. Retrieved 23 April 2024.
  9. 1 2 "House Finch Eye Disease". Project FeederWatch. The Cornell Lab of Ornithology. Archived from the original on 16 August 2024. Retrieved 23 April 2024.
  10. ↑ Adelman, James S.; Moyers, Sahnzi C.; Farine, Damien R.; Hawley, Dana M. (22 September 2015). "Feeder use predicts both acquisition and transmission of a contagious pathogen in a North American songbird". Proceedings of the Royal Society B: Biological Sciences. 282 (1815). doi:10.1098/rspb.2015.1429. PMC   4614752 . PMID   26378215. Archived from the original on 16 August 2024. Retrieved 24 April 2024.
  11. ↑ "New research links House Finch behavior at feeders to the acquisition and spread of eye disease". Project FeederWatch. The Cornell Lab of Ornithology. 23 September 2015. Archived from the original on 24 April 2024. Retrieved 24 April 2024.
  12. ↑ "Songbird diseases encountered at bird feeders". Utah Division of Wildlife Resources. 20 October 2023. Archived from the original on 24 April 2024. Retrieved 24 April 2024.
  13. 1 2 3 4 "Mycoplasma gallisepticum Infection in Poultry" Archived 2015-03-25 at the Wayback Machine in The Merck Veterinary Manual for Veterinary Professionals (2013).
  14. ↑ The Poultry Site. (2013). Mycoplasma gallisepticum infection, M.g., Chronic Respiratory Disease – Chickens Archived 2018-03-25 at the Wayback Machine .
  15. ↑ Valks, M. and Burch, D. (2002). The Treatment and Control of Mycoplasma Infections in Turkey Archived 2020-02-18 at the Wayback Machine . Octagon Services Ltd., Old Windsor, Berks, United Kingdom.
  16. ↑ The Center for Food Security & Public Health. (2013). Avian Mycoplasmosis (Mycoplasmagallisepticum) Archived 2020-04-12 at the Wayback Machine .
  17. 1 2 TEKKALAN, Mümtaz Recep (May 2020). "Kümes Hayvanlarında Mycoplasma gallisepticum'un Tespiti için Lam Aglütinasyon, ELISA ve PCR Testlerinin Karşılaştırılması": 36–52.{{cite journal}}: Cite journal requires |journal= (help) Archived 2024-08-16 at the Wayback Machine
  18. ↑ Peebles, E.D.; Branton, S.L. (2012). "Mycoplasma gallisepticum in the commercial egg-laying hen: an historical perspective considering effects of pathogen strain, age of bird at inoculation, and diet on performance and physiology". The Journal of Applied Poultry Research. 21 (4): 897–914. doi: 10.3382/japr.2012-00555 .
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.