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| | + | |pagetitle =Mycoplasmas |
| | + | |pagebody =The Mycoplasmas are small free-living prokaryotic organisms. They cause many diseases, notably respiratory diseases in farm animals including [[Contagious Bovine Pleuropneumonia]]. |
| | + | |contenttitle =Content |
| | + | |contentbody =<big><b> |
| | + | <categorytree mode=pages>Mycoplasmas</categorytree> |
| | + | </b></big> |
| | + | |logo =bugs-logo copy.png |
| | + | }} |
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| − | ===Overview===
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| − | *Pathogens belong to the ''Mycoplasma'' and ''Ureaplasma'' genera
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| − | *Cause many diseases especially respiratory diseases of farm animals including contagious bovine pleuropneumonia
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| − | *Can be involved in mastitis and conjunctivitis in cattle
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| − | *Implicated in respiratory and urinary tract diseases in dogs and cats
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| − | *Non-pathogenic mycoplasmas present in the rumen
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| − | *Live on mucous membranes of oronasal cavity, conjunctiva and intestines
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| − | *Stress factors and concurrent disease may predispose to tissue invasion
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| − | *Usually host-specific
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| − | *Limited survival in the environment
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| − | | + | [[Category:Bacterial Organisms]] |
| − | ===Characteristics===
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| − | | |
| − | *Smallest free-living prokaryotic organism
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| − | *Pleomorphic organisms
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| − | *Have no peptidoglycan cell wall
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| − | *Susceptible to dessication, heat and disinfectants
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| − | *Require enriched media containing animal protein, sterol and a source of DNA for growth
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| − | *Colonies have a fried egg appearance
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| − | *Most are facultative anaerobes
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| − | ===Pathogenesis and pathogenicity===
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| − | *Mycoplasmas adhere to host cells and produce toxins
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| − | *Some adhere to [[Neutrophils - WikiBlood|neutrophils]] and macrophages and prevent phagocytosis
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| − | *Mycoplasmas induce proliferation of macrophages and [[[[Monocytes - WikiBlood|monocytes]]]], and release of cytokines such as TNF and interleukins
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| − | *Cause damage to cilia in the respiratory tract leading to pneumonia
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| − | *Molecular mimicry allows some mycoplasmas to avoid the host immune response and may initiate immune-mediated disease
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| − | ===Diagnosis===
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| − | *Samples can be tested for the presence of mycoplasmas by fluorescent antibody techniques, peroxidase techniques and PCR
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| − | *Biochemical profiles such as urease production can be used for identification
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| − | *''Ureaplasmas'' produce urease, whereas ''Mycoplasmas'' do not metabolise urea
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| − | *Serolgy is required for specific identification including complement fixation tests, ELISA, agglutination tests and haemagglutination-inhibition tests
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| − | *Growth inhibition tests using specific antisera can be used as well as fluorescent antibody tests
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| − | ===[[Respiratory Bacterial Infections - Pathology#Contagious bovine pleuropneumonia (CBPP)|Contagious bovine pleuropneumonia]]===
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| − | *[[Respiratory Bacterial Infections - Pathology#Contagious bovine pleuropneumonia (CBPP)|Contagious bovine pleuropneumonia]] is caused by ''M. mycoides'' subsp. ''mycoides'' small colony type
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| − | *A severe contagious disease of cattle
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| − | *Endemic in Africa, the Middle East and Asia
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| − | *Aerosol transmission by close contact with clinically or subclinically affected animals
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| − | *Severity depends on strain and host susceptibility
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| − | *Slow spread of infection
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| − | *50% morbidity; mortality rate high in severe outbreaks
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| − | *Large colony type causes pleuropneumonia, mastitis, septicaemia and polyarthritis
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| − | | |
| − | *Clinical signs
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| − | **Acute onset fever, anorexia, depression, lowered milk yield, hyperpnoea, coughing and a mucopurulent nasal discharge
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| − | **Dyspnoea occurs with abducted elbows and extended necks and an expiratory grunt
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| − | **Can be fatal within 1-3 weeks
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| − | **Calves may suffer from [[Joints Inflammatory - Pathology#In Cattle|arthritis]], synovitis and endocarditis
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| − | *Gross pathology
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| − | **Marbled appearance to lungs with consolidated grey and red lobules separated by emphysematous areas
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| − | **Serofibrinous pleural fluid
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| − | **Necrotic foci surrounded by fibrous capsules in chronic cases act as source of infection
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| − | *Diagnosis
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| − | **Clinical signs and post-mortem appearance
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| − | **PCR on pleural fluid, lung tissue, regional lymph nodes or bronchoalveolar lavage fluid
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| − | **Fluorescent antibody test
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| − | **Serological tests such as serum agglutination, haemagglutination, complement fixation, ELISA
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| − | *Treatment and control
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| − | **Slaughter of affected cattle in counries where the disease is exotic
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| − | **Movement restrictions, quaranteen and slaughter of carrier animals in endemic countries
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| − | **Vaccination in endemic regions
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| − | ===''Mycoplasma bovis''===
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| − | *Causes severe pneumonia in calves as a primary pathogen
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| − | *Can occur secondarily to ''Pasteurella'' and ''Mannheimia'' and [[Respiratory Viral Infections - Pathology#In Cattle|IBR]]
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| − | *Associated with [[Joints Inflammatory - Pathology#In Cattle|arthritis]] and mastitis
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| − | *Mastitis associated with a severe drop in milk yield and a purulent discharge
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| − | ===Contagious agalactia of sheep and goats===
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| − | *Severe febrile disease of sheep and goats in parts of Europe, Africa, Asia
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| − | *Caused by ''M. agalactiae''
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| − | *Mastitis, arthritis and conjunctivitis following parturition
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| − | *Causes abortion
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| − | *Fatal pneumonia in young animals
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| − | *Shed in milk; localised in supramammary lymph nodes
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| − | *Inactivated, attenuated vaccines available
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| − | ===Contagious caprine pleuropneumonia===
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| − | *Caused by ''M. capricolum'' subsp. ''capricolum'; occasionally ''M. mycoides'' subsp. ''capri'' or ''M. mycoides'' subsp. ''mycoides''
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| − | *Occurs in Africa and Turkey
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| − | *Pneumonia, fibrinous pleurisy, pleural exudate, consolidated and emphysematous lungs
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| − | *Aerosol transmission; highly contagious
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| − | *Identified by growth inhibition disc tests
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| − | *Inactivated vaccines available
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| − | *''M. mycoides'' subsp. 'mycoides'' causes septicaemia, pleuropneumonia, arthritis and mastitis in goats
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| − | ===[[Respiratory Bacterial Infections - Pathology#Enzootic pneumonia of pigs|Enzootic pneumonia of pigs]]===
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| − | *[[Respiratory Bacterial Infections - Pathology#Enzootic pneumonia of pigs|Enzootic pneumonia of pigs]] caused by ''M. hyopneumoniae''
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| − | *Occur in unfavourable conditions with poor ventilation, overcrowding and temperature fluctuations
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| − | *Stunted growth rates, coughing and occasionally respiratory distress
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| − | *Consolidation in apical and cardiac lung lobes
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| − | *Immunofluorescence of lung tissue and complement fixation test or ELISA used for identification
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| − | *Treatment includes in-feed antibiotics such as tylosin, lincomycin and tiamulin
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| − | *Absent in specific-pathogen-free herds
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| − | ===''M. hyorhinis'' and ''M. hyosynoviae'' of pigs===
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| − | *''M. hyosynovia'' and ''M. hyorhinis'' produce syndromes similar to [[Haemophilus parasuis|Glasser's disease]] with milder expression, rarely menigitis and [[Joints Inflammatory - Pathology#In Pigs|arthritis]]
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| − | *''M. hyorhinis causes a chronic progressive polyserositis in pigs under 10 weeks old
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| − | *A fever, laboured breathing, lameness and swollen joints occur
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| − | *Serofibrinous pleurisy, pericarditis and [[Peritoneal Cavity Inflammatory - Pathology#In pigs|peritonitis]] occur
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| − | *Treatment includes tylosin and lincomycin
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| − | *''M. hyorhinis'' causes a polyarthritis in pigs of 10-30 weeks old, leading to transient lameness
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| − | ===Mycoplasmas of poultry===
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| − | *''M. gallisepticum''
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| − | **Causes chronic repsiratory disease in chickens and infectious sinusitis in turkeys
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| − | **Transmission via the egg and aerosol
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| − | **Reduced egg production
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| − | **Identification by serum plate agglutination test, haemagglutination inhibition and ELISA
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| − | **Controlled in specific-pathogen-free flocks
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| − | **Modified live vaccines and bacterins available
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| − | *''M. meleagridis''
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| − | **Hatching problems; airsacculitis in young poults; joint and bone deformities in growers; poor growth rates
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| − | **Transmitted mainly via eggs and semen
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| − | **Serum plate agglutination test for identification
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| − | **In-water tylosin for first 10 days of life
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| − | **Eggs can be dipped in tylosin
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| − | *''M synoviae''
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| − | **Causes infectious synovitis in chickens and turkeys
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| − | **Transmitted by aerosol
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| − | **Synovitis, arthritis, respiratory disease
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| − | **Confirmation by isolation or serology
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| − | **In-feed tetracycline
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| − | **Eradication through specific-pathogen-free flocks
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| − | ===Other mycoplasmas===
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| − | *''M. bovis'', ''M. dispar'' and ''Ureaplasma'' can be involved in [[Respiratory Bacterial Infections - Pathology#Enzootic pneumonia of calves|Enzootic pneumonia of calves]]
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| − | *''M. ovipneumoniae'' is implicated in [[Respiratory Bacterial Infections - Pathology#Enzootic pneumonia of lambs|enzootic pneumonia of lambs]]
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| − | *''M. felis'' may be involved in mild [[Respiratory Bacterial Infections - Pathology#Mycoplasma felis|respiratory infection]]
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| − | *Mycoplasmas may cause [[Chronic Inflammation - Pathology#Lymphocytic Inflammation|lymphocytic chronic inflammation]] (peribronchiolar and perialveolar cuffing)
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| − | *Cause [[Peritoneal Cavity Inflammatory - Pathology#In sheep|peritonitis in sheep]], [[Peritoneal Cavity Inflammatory - Pathology#In goats|peritonitis in goats]] and [[Peritoneal Cavity Inflammatory - Pathology#In pigs|peritonitis in pigs]]
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| − | [[Category:Infectious_Agents]] | |
