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1. MYCOPLASMAS PTM 4310

2. INTRODUCTION These are a class of bacteria that lack a cell wall Smallest free-living bacteria in nature, also able to replicate on laboratory media Species of importance include: M. Pneumoniae M. hominis U. urealyticum M. genitalium

3. CHARACTERISTICS The outer membrane functions as the major antigenic interface It is a flexible triple layered structure of proteins and lipids Laboratory identification of infection is based on serology because of difficulties of culture Most species are fastidious May require complex media or soft agar for satisfactory culture at 35˚c- 37˚c

4. The colonies on agar have a fried egg appearance Requirements for growth allow one to differentiate between species M. pneumoniae - glucose M. hominis - arginine U. urealyticum - urea (buffered media due to growth inhibition by alkaline media) M. genitalium - difficult to culture

5. Cells are variable in size and morphology Impression of colonies can be stained by diene’s or Romanowsky’s stains Antigenic properties : surface glycoproteins surface proteins Immunopathogenesis Activate macrophages Stimulate cytokine production Superantigen ( M. pneumoniae) Inflammatory cells migrate to infection and release TNF-a then IL-1 and IL-6

6. Produce surface infections – adhere to the mucosa of respiratory , gastrointestinal & genitourinary tracts with the help of adhesin. Two types of diseases: Atypical Pneumonia Genital infections

7. Organism Disease M. pneumoniae Upper respiratory tract disease, tracheobronchitis, atypical pneumonia, (chronic asthma?) M. hominis Pyelonephritis, pelvic inflammatory disease, postpartum fever M. genitalium Nongonococcal urethritis U. urealyticum Nongonococcal urethritis, (pneumonia and chronic lung disease in premature infants?)

8. MYCOPLASMA PNEUMINIEA REPRODUCTION Via binary fission with well organized chromosome segregation. Before binary fission: Specialized cellular structure –attachment organelle- duplicates Daughter organelle migrates to the opposite pole of the cell Attachment organelle on each daughter cell will bind to a surface initiate gliding motility

9. PATHOGENESIS Once bound to host tissue, M. pneumoniae will produce hydrogen peroxide and superoxide through the metabolism of glycerol. H 2 O 2 and O 2 - will then cause injury to the epithelial cells and their associated cilia. The effects of hydrogen peroxide on host cells such as erythrocytes include denaturation of hemoglobin, peroxidation of lipids, and eventual cell lysis. The same oxidative stress in the respiratory epithelium can result in both structural and functional deterioration of cilia. The CARDS toxin (similar to pertussis toxin), facilitates localized disruption and cytotoxicity which is exhibited by distinct vacuolization and cell rounding. Interaction between respiratory epithelial cells and surface lipoproteins of M. pneumoniae is likely to induce the host immune system via Toll-like receptor TLR-2 or TLR-4 stimulating the synthesis of intracellular adhesion molecule (ICAM) receptors.

10. EPIDEMIOLOGY Able to infect both the upper and lower respiratory tracts of both adults and children worldwide Cause both epidemic and endemic situations Spread through aerosol droplets from person to person Immunity is short term- relapses occur even with strict adherence to antibiotic regime P1 adhesin genomic variation facilitates the short term immunity

11. CLINICAL MANIFESTATION Incubation period may be short, but may also last 3 weeks Acute infection presents as a dry cough and within 3-4 days, it develops into a wet cough The cough represents the progressing tracheobronchitis Atypical pneumonia observed in adult patients portrays a gradual onset of pharyngitis, sinus congestion, infrequent otitis media and eventually prolonged lower respiratory involvement. This will result in and include pneumonia with low-grade fever and bibasilar pulmonary infiltrates in severe cases, dry rales and frank consolidation may be observed

12. complaints may include: Sore throat, headache, ear pain and chest pain Laboratory profile: sputum not viscous mild leukocytosis Chest images depict bronchopneumonia due to the ciliated cell damage that occurs with immune response Severe pneumonia necessitates hospitalization due to decreased blood oxygen

13. Radiography and CT scan Air space opacification Bronchovascular thickening Atelectasis Nodular infiltration Linear opacities outward from the hilium Can be isolated in healthy individuals These asymptomatic/ mild infections still allow for shedding of the pathogen OTHER RESPIRATORY MANIFESTATIONS Chronic respiratory diseases like asthma and persistent cough (e.g. Bordetella pertussis ) Facilitates mucosal penetration by other antigens due to the destruction of respiratory cells

14. EXTRAPULMONARY MANIFESTATIONS Skin Nervous Renal Gastrointestinal Musculoskeletal Hematologic The host immune response contributes to these complications as well as autoimmunity Complications that occur in the CNS are recognized as the most common e.g. pediatric encephalitis, cranial nerve palsy, aseptic meningitis among others

15. PREVENTION AND TREATMENT Prevention Avoid close contact Isolation is not practical due to length of illness No vaccine, although attempted Treatment Tetracycline in adults (doxycycline) or erythromycin (children) Newer fluoroquinolones (in adults) Resistant to cell wall synthesis inhibitors. Tetracycline, Erythromycin & Clarithromycin – drug of choice

16. MYCOPLASMA GENITALIUM Associated with non-gonococcal urethritis in both men and women (also cervicitis) Prevalent in sexually active age groups Asymptomatic carriers exist

17. UREAPLASMA UREALYTICUM Strains of mycoplasma isolated from the urogenital tract of human beings & animals. Form very tiny colonies - hence called T strain or T form of mycoplasmas. Hydrolyzes urea

18. GENITAL INFECTIONS Caused by M. hominis & U. urealyticum Transmitted by sexual contact Men - Nonspecific urethritis, proctitis, balanoposthitis & Reiter’s syndrome Women – acute salpingitis, PID, cervicitis, vaginitis Also associated with infertility, abortion, postpartum fever, chorioamnionitis & low birth weight infants

19. Treatment Tetracycline or erythromycin U. urealyticum is resistant to tetracycline M. hominis is resistant to erythromycin and sometimes to tetracyclin, Clindamycin for these resistant strains Prevention Abstinence or barrier protection No vaccine

20. THANKS FOR THE ATTENTION!