Mycoplasma

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Mycoplasma

  1. 1. Mycoplasma G-ve
  2. 3. <ul><li>Devoid of cell wall-highly pleomorphic </li></ul><ul><li>Lack even cell wall precursors-muramic acid </li></ul><ul><li>Cells are bounded by trilaminar unit membrane containing sterols </li></ul><ul><li>PPLO was replaced by Mycoplasma </li></ul>
  3. 4. <ul><li>FamilyMycoplasmataceae </li></ul><ul><li>Genus-Mycoplasma </li></ul><ul><li>Genus Ureaplasma </li></ul><ul><li>Family Acholeplasmataceae </li></ul><ul><li>Mycoplasma –saprophytic,parasitic,pathogenic </li></ul><ul><li>M.pneumoniae </li></ul><ul><li>M.hominis </li></ul><ul><li>U.Urealyticum </li></ul><ul><li>Acholeplasma laidlawii </li></ul>
  4. 5. <ul><li>Morphology </li></ul><ul><li>Smallest free living micro organisms—most plemarphic </li></ul><ul><li>Occur as granules and filaments of various sizes </li></ul><ul><li>In some—bulbous enlargement with a differebtiated tip structure—attached to suitable host cell carrying neuraminic acid receptors-may be responsible for the hemadsorption shown by some species </li></ul>
  5. 6. <ul><li>No spores,flagella,fimbria </li></ul><ul><li>Gliding motility </li></ul><ul><li>G-ve </li></ul><ul><li>In culture-high quanity of serum is necessary as a souce of cholesterol and other lipids </li></ul><ul><li>Colonies are typically biphasic,with fried egg appearance </li></ul><ul><li>Are chemo organotrophs </li></ul><ul><li>Unique among prokaryotes—requirement of cholesterol and sterols-which are incorporated in their surface membrane </li></ul>
  6. 7. <ul><li>Resistance-o penicillins,cephalosprins,lysozymes,which act on bacterial cell walls---but sensitive to tetracyclines and erythromycin,macrolides </li></ul><ul><li>-used for species differentiation </li></ul><ul><li>Growth is inhibited by gold salts </li></ul><ul><li>M.pneumoniae-can grow in presence of .002% methylene blue in agar,while many other species are inhibited </li></ul>
  7. 8. <ul><li>Surface antigens-glycolipids and proteins </li></ul><ul><li>Pathogenicity – produce surface infection by adhering to mucosa of respiratory,GI,GU tract. </li></ul><ul><li>Mycoplasma can cause—pneumonia & genital infections </li></ul><ul><li>Mycoplasmal pneumoniae--/primary atypical pneumoniae—by M.pneumoniae—typically –tracheobronchitis- </li></ul><ul><li>Only one third develops pneumoniae </li></ul>
  8. 9. <ul><li>Onset is gradual- with fever malaise,headache,sore throat </li></ul><ul><li>Paroxysmal cough with blood tinged sputum </li></ul><ul><li>Paucity of respiratory signs </li></ul><ul><li>Patchy radiological consolidation-starting at the hilum and fanning out to the periphery </li></ul><ul><li>Self limited-1-2 wks </li></ul><ul><li>Complications—bullous myringitis and otitis </li></ul>
  9. 10. <ul><li>Transmission –droplet infection </li></ul><ul><li>Lab dig-isolation,throat swabs---glucose and phenol red medium—growth indicated by acid production </li></ul><ul><li>M.pneumoniae-beta hemolysis and agglutinates guinea pig erythrocytes </li></ul><ul><li>Serolog.d –IF,HI,MI </li></ul><ul><li>CF,streptococcus MG,Cold agglutination tests.. </li></ul>
  10. 11. Streptococcus M G <ul><li>Serum + heat killed suspension of Streptococcus M G suspension-----37C---overn8—agglutination </li></ul><ul><li>Titre 1:20 is positive </li></ul>
  11. 12. Cold agglutination test <ul><li>Principle :- Antibodies formed in atypical pneumonia---agglutinate O group RBC at low temp </li></ul><ul><li>Serum + O group RBC---4C ---overn8-----clumping </li></ul><ul><li>1:32 --positive </li></ul>
  12. 13. <ul><li>Ureaplasma Urealyticum </li></ul><ul><li>Isolated from urogenital tract </li></ul><ul><li>Forms very tiny colonies </li></ul><ul><li>Called T-strains/T-form mycoplasmas </li></ul><ul><li>Hydrolyse urea-which is an essential growth factor in addition to cholesterol </li></ul><ul><li>Genital i9nfections-M.hominis,UU—transmitted by sexual contact----urethritis,proctitis,balanoposthitis,reiter’s syndrome,a/c salpingitis,pelvic inflammatory disease,cervicitis,vaginitis </li></ul><ul><li>Also associated with—infertility,abortion,PPf,chorioamniontitis,low birth weight </li></ul>
  13. 14. <ul><li>Mycoplasma-more inf. In hiv </li></ul><ul><li>Contaminant in cell culture </li></ul><ul><li>L forms- bacteria loses part or whole of the cell wall-may be stable /unstable </li></ul><ul><li>Stable forms—Mycoplasma </li></ul><ul><li>Unstable – will get back to normal forms </li></ul>

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