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Mollicutes. Mollicutes. The smallest cells capable of self-replication Lack cell wall (peptidoglycan & outer membrane) Highly fastidious Diagnosis is difficult Species show host specificity No classical virulence determinants Typically chronic infection. Mollicutes - Mycoplasmas.
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Mollicutes The smallest cells capable of self-replication Lack cell wall (peptidoglycan & outer membrane) Highly fastidious Diagnosis is difficult Species show host specificity No classical virulence determinants Typically chronic infection
Mollicutes - Mycoplasmas "minimal" cells: physiologically restricted - highly fastidious lack cell wall (peptidoglycan) pleomorphic Fried-egg-shaped micro-colonies
Diagnosis pathology - gross & histopathology isolation & identification: phenotypic/biochemical serological response antigenic detection genomic detection
Mollicutegenera Mycoplasma ~100 species; pathogens & commensals Ureaplasma pathogens & commensals Spiroplasma plant pathogens; insect commensal (? pathogens) Anaeroplasma rumen commensal Acholeplasma mainly commensal
Virulence mechanisms of mollicutes adhesins competition for metabolites degradative enzymes cytotoxic metabolites (H2O2; NH4+) endotoxicity (lipogalactan & lipopeptides) antigenic variation intraphagocytic survival assimilation of host cell antigens autoimmunity superantigenicity antigen persistence
Mycoplasma diseases 1 e.g. respiratory Pneumonia & chronic respiratory diseases M. gallisepticum poultry chronic respiratory disease M. bovis calf "cuffing" pneumonia M. hyopneumoniae enzootic pneumonia of swine M. ovipneumoniae ovine proliferative interstitial pneumonia M. capricolum subsp. capri ovine & caprine respiratory infections M. meleagridis poultry air sacculitis M. equi equine respiratory disease M. capricolum subsp. capripneumoniae - CCPP (contagious caprine pleuropneumonia) Pleuropneumonia M. mycoides subsp. mycoides - CBPP (contagious bovine pleuropneumonia)
Mycoplasma diseases 2 e.g. mucosal Conjunctivitis/Keratitis M. conjunctivae ovine, bovine Reproductive infections U. diversum infertility, abortion Mastitis M. bovis bovine mastitis M. bovoculi; U. diversum (bovine) M. bovigenitalium epididymitis M. californicum, M. canadense (bovine) Mycoplasma diseases 3 e.g. invasive Arthritis/Synovitis M. synoviae poultry Multisystem infection M. agalactiae sheep, goats Anaemia M. haemofelis cats M. haemosuis pigs M. bovis (cattle) M. hyorhinis (pigs) M. arthritidis (rodents) M. mycoides subsp. mycoides LC sheep, goats M. mycoides subsp. capri goats M. capricolum subsp. capricolum sheep, goats
Respiratory mycoplasmoses Inhalation adherence to ciliated epithelium Colonisation of bronchioles/alveoli Ciliostasis and “ciliotoxicity” Immunomodulation / immune evasion Alveolar & peribronchial inflammation (“cuffing”; MN, PMN, L, plasma cells) mononuclear cell infiltration & hyperplasia LN enlargement consolidation catarrhal exudation freq. chronic - persists months/years
adherence to ciliated epithelium mononuclear cell infiltration &hyperplasia consolidation Respiratory mycoplasmoses Ciliostasis and “ciliotoxicity”
bovine M. bovis } M. dispar } U. diversum } "cuffing" pneumonia; co-infection with M. haemolytica / H. somnus poultry M. gallisepticum Chronic Respiratory Disease (CRD) M. meleagridis respiratory mycoplasmoses ovine M. ovipneumoniae proliferative interstitial pneumonia ovine atypical pneumonia
Contagious Pleuropneumonia Contagious Bovine Pleuropneumonia - CBPP M. myciodes subsp. mycoides SC Contagious Caprine Pleuropneumonia - CCPP M. capricolum subsp. capripneumoniae • Notifiable diseases • usu. acute/per-acute course • occ. sub-acute/chronic • high mortality • highly contagious • remission & re-activation chronic carriers • MN cell infiltration & proliferation • neutrophil infiltration necrosis • fluid exudation • vascular inflammation
MAKEPS Multisystemic mycoplasmosis mycoplasmaemia malaise, fever prostration inappetance mastitis (severe: milk production, fibrinous, pus) arthritis keratitis/conjunctivitis polyserositis septicaemia m a ke p s e.g. Mycoplasma agalactiae - Contagious agalactia; NOTIFIABLE DISEASE
Infectious Anaemia arthropod transmitted • Mycoplasma haemofelis Mycoplasma haemosuis adhere to erythrocytes indentations/rupture erythrocyte lysis anaemia
Control of mycoplasmoses test & slaughter disease-free herds/flocks selective breeding antibacterial chemotherapy: vaccines: inactivated / attenuated