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#REDIRECT[[:Category:Mycoplasmas]]
 
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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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===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 and macrophages and prevent phagocytosis
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*Mycoplasmas induce proliferation of macrophages and 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''
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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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*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. ''mcoides''
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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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===Enzootic pneumonia of pigs===
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*Caused by ''M. hyopneumonia''
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*Cause [[Peritoneal Cavity Inflammatory - Pathology#In sheep|peritonitis in sheep]] and [[Peritoneal Cavity Inflammatory - Pathology#In goats|peritonitis in goats]] and [[Peritoneal Cavity Inflammatory - Pathology#In pigs|peritonitis in pigs]]
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*[[Respiratory Bacterial Infections - Pathology#Enzootic pneumonia of pigs|Enzootic pneumonia of pigs]] caused by ''M. hyopneumoniae'' and ''M. hyorhinis''
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*''M. bovis'', ''M. dispar'' and ''Ureaplasma'' in [[Respiratory Bacterial Infections - Pathology#Enzootic pneumonia of calves|Enzootic pneumonia of calves]]
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* May cause [[General Pathology - Chronic Inflammation#Lymphocytic Inflammation|lymphocytic chronic inflammation]] (peribronchiolar and perialveolar cuffing).
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*''M. felis'' in mild [[Respiratory Bacterial Infections - Pathology#Mycoplasma felis|respiratory infection]]
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*''M. ovipneumoniae'' in [[Respiratory Bacterial Infections - Pathology#Enzootic pneumonia of lambs|enzootic pneumonia of lambs]]
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*''M. hyosynovia'' and ''M. hyorhinis'' produce syndrome similar to [[Haemophilus species|Glasser's disease]] with milder expression, menigitis rare, [[Joints Inflammatory - Pathology#In Pigs|arthritis]] most consistent
 
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