Mycoplasma are the smallest free-living microorganisms lacking a cell wall. They can cause respiratory infections like pneumonia through surface adhesion to the respiratory tract. Mycoplasma pneumoniae is a common cause of atypical pneumonia where symptoms include a gradual onset of fever, malaise, headache, and cough. Laboratory diagnosis involves isolation from throat swabs and serological tests. Mycoplasma can also cause genital infections transmitted sexually, associated with conditions like urethritis, pelvic inflammatory disease, and infertility.

1. Mycoplasma G-ve

3. Devoid of cell wall-highly pleomorphic Lack even cell wall precursors-muramic acid Cells are bounded by trilaminar unit membrane containing sterols PPLO was replaced by Mycoplasma

4. FamilyMycoplasmataceae Genus-Mycoplasma Genus Ureaplasma Family Acholeplasmataceae Mycoplasma –saprophytic,parasitic,pathogenic M.pneumoniae M.hominis U.Urealyticum Acholeplasma laidlawii

5. Morphology Smallest free living micro organisms—most plemarphic Occur as granules and filaments of various sizes 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

6. No spores,flagella,fimbria Gliding motility G-ve In culture-high quanity of serum is necessary as a souce of cholesterol and other lipids Colonies are typically biphasic,with fried egg appearance Are chemo organotrophs Unique among prokaryotes—requirement of cholesterol and sterols-which are incorporated in their surface membrane

7. Resistance-o penicillins,cephalosprins,lysozymes,which act on bacterial cell walls---but sensitive to tetracyclines and erythromycin,macrolides -used for species differentiation Growth is inhibited by gold salts M.pneumoniae-can grow in presence of .002% methylene blue in agar,while many other species are inhibited

8. Surface antigens-glycolipids and proteins Pathogenicity – produce surface infection by adhering to mucosa of respiratory,GI,GU tract. Mycoplasma can cause—pneumonia & genital infections Mycoplasmal pneumoniae--/primary atypical pneumoniae—by M.pneumoniae—typically –tracheobronchitis- Only one third develops pneumoniae

9. Onset is gradual- with fever malaise,headache,sore throat Paroxysmal cough with blood tinged sputum Paucity of respiratory signs Patchy radiological consolidation-starting at the hilum and fanning out to the periphery Self limited-1-2 wks Complications—bullous myringitis and otitis

10. Transmission –droplet infection Lab dig-isolation,throat swabs---glucose and phenol red medium—growth indicated by acid production M.pneumoniae-beta hemolysis and agglutinates guinea pig erythrocytes Serolog.d –IF,HI,MI CF,streptococcus MG,Cold agglutination tests..

11. Streptococcus M G Serum + heat killed suspension of Streptococcus M G suspension-----37C---overn8—agglutination Titre 1:20 is positive

12. Cold agglutination test Principle :- Antibodies formed in atypical pneumonia---agglutinate O group RBC at low temp Serum + O group RBC---4C ---overn8-----clumping 1:32 --positive

13. Ureaplasma Urealyticum Isolated from urogenital tract Forms very tiny colonies Called T-strains/T-form mycoplasmas Hydrolyse urea-which is an essential growth factor in addition to cholesterol Genital i9nfections-M.hominis,UU—transmitted by sexual contact----urethritis,proctitis,balanoposthitis,reiter’s syndrome,a/c salpingitis,pelvic inflammatory disease,cervicitis,vaginitis Also associated with—infertility,abortion,PPf,chorioamniontitis,low birth weight

14. Mycoplasma-more inf. In hiv Contaminant in cell culture L forms- bacteria loses part or whole of the cell wall-may be stable /unstable Stable forms—Mycoplasma Unstable – will get back to normal forms