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| + | #REDIRECT[[:Category:Mycoplasmas]] |
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| − | |linkpage =Bacteria
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| − | |linktext =BACTERIA
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| − | |pagetype=Bugs
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| − | <br>
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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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