Mycoplasma

1. Mycoplasma By Dr. Emad AbdElhameed Morad Lecturer of Medical Microbiology and Immunology

2. Species • Mycoplasma pneumonia • Genital mycoplasma: • Mycoplasma genitalium • Ureaplasma urealyticum • Mycoplasma hominis

3. Diseases • Mycoplasma pneumonia: atypical pneumonia • Genital mycoplasma: • Mycoplasma genitalium: non gonococcal urethritis • Ureaplasma urealyticum: non gonococcal urethritis • Mycoplasma hominis: postpartum fever + salpingitis Non gonococcal urethritis Salpingitis

4. Mycoplasma pneumonia

5. Morphology The smallest organisms (50 – 300 nm). They lack cell wall. So: Pleomorphic in shape. Not stained with Gram. But stained with Dienes stain. Resistant to penicillin and cephalosporins. Pleomorphism

7. Cultural characters Mycoplasma contain sterol in their cell membrane. So, they are grown on special media like PPLO agar. Facultative anaerobe. Require 10% CO2. Require at least 1 weekto grow on culture. They take fried egg appearanceon culture.

8. Fried egg appearance

9. Laboratory diagnosis of atypical pneumonia

10. Specimen: Sputum or nasopharyngeal secretions. Culture: Difficult & time consuming. Direct detection in clinical specimen: IF PCR Serological diagnosis: Detection of IgM or rising titer of IgGby ELISA or CFT. Cold agglutinins at a titer of 1/128 or higher = acute infection. Most useful

11. Cold agglutinins? Positive in? Specific? • Certain antigens on human red blood cellsare identical to Mycplasma pneumonia antigens. So, antibodies to mycoplasmacross react with human red blood cells causing them to agglutinate at 4 degreebut not at 37 degree. • Positive in 50 % of cases. • Non specific. Positive in other diseases like viral infections & malaria

12. Treatment • Tetracycline, erythromycin or azithromycin.

13. Best Regards