Mycoplasma spp
- 2. Mycoplasma Group of bacteria that lack a cell wall around their cell membranes There are more than 200 known species in the class of Mollicutes (cell wall–free bacteria). At least 16 of these species are thought to be of human origin; others have been isolated from animals and plants.
- 4. classification Phylum : Tenericutes Class : Mollicutes Order : Mycoplasmatales Family : Mycoplasmataceae Genus : mycoplasma
- 5. EPIDEMIOLOGY The mycoplasmas usually considered as commensals (normal flora) are listed in Table
- 8. Mycopasma characteristics the smallest organisms that can be free living in nature and self-replicating on laboratory media. the smallest mycoplasmas are 125–250 nm in size pass through filters with 450-nm pore size they are highly pleomorphic bounded by a triple-layered “unit membrane” that contains a sterol completely resistant to penicillin but they are inhibited by tetracycline or erythromycin
- 9. Mycopasma characteristics parasitic mode of life. According to express a small number of cell proteins and lack many enzymatic activities and metabolic pathways. Require complex media for growth Facultative anaerobes Except M. pneumoniae - strict aerobe Grow slowly by binary fission great difficulty of cultivation in the laboratory
- 10. mycoplasma genome Small genome size (M. pneumoniae is ~800 Kbp) typically prokaryotic Consisting of a circular, dsDNA there are very few genes; estimated at fewer than 500
- 11. Transmittion direct sexual contact, transplanted tissue from donor to recipient from mother to fetus during childbirth or in utero. transmitted by respiratory secretions.
- 12. PATHOGENESIS mycoplasmas that infect humans and other animals are surface parasites adhering to the epithelial linings of the respiratory and urogenital tracts. have flasklike or filamentous shapes and have specialized polar tip structures that mediate adherence to host cells. These structures are a complex group of interactive proteins adhesins (eg, the P1 adhesin of M pneumonia and the MgPa adhesin of M genitalium) adherence accessory proteins attach to the surfaces of ciliated and nonciliated cells,
- 14. PATHOGENESIS Toxic metabolic products Peroxide and superoxide Inhibition of catalase Immunopathogenesis Activate macrophages Stimulate cytokine production Superantigen (M. pneumoniae) Inflammatory cells migrate to infection and release TNF- a then IL-1 and IL-6
- 15. Mycoplasma pneumoniae Cause Upper respiratory tract disease, tracheobronchitis atypical pneumonia Asymptomatic infection Upper respiratory tract infection in school-aged children: mild, nonspecific symptoms Including: runny nose pharyngitis coryza (symptoms of a head cold, stuffy or runny nose, cough, aches) most without fever
- 16. Mycoplasma pneumoniae Lower respiratory tract infection in adolescents or young adults: typically mild illness with nonproductive cough fever malaise, Pharyngitis myalgias
- 17. Mycoplasma pneumoniae develop pneumonia; complications include: rash arthritis encephalitis Myocarditis Pericarditis hemolytic anemia Occasionally the organism has been associated with infection in children < 5 years of age and elderly patient
- 18. Genital Mycoplasma Mycoplasma hominis : Pyelonephritis, pelvic inflammatory disease postpartum fever Ureaplasma urealyticum : nongonococcal urethritis Systemic infections in neonates as a result of vertical transmission from the mother to the fetus in 18%-55% when the mother is colonized: meningitis Abscess bacteremia pneumonia; U. urealyticum is also associated with the development of chronic lung disease
- 19. Genital Mycoplasma Urogenital tract infections: Prostatitis pelvic inflammatory disease (PID) amnionitis nongonococcal urethritis acute polynephritis Invasive disease in immunosuppressed patients: bacteremia arthritis abscesses other wound infections pneumonia peritonitis
- 20. Mycoplasma genitalium cause urogenital infections Nongonococcal urethritis in men cause of cervicitis and endometritis in females Vertical transmission from mother to fetus has been identified however, the clinical significance is currently unknown.
- 22. DIGNOSIS
- 23. SPECIMEN COLLECTION, TRANSPORT, Various specimens are appropriate for the diagnosis of mycoplasma infections by culture or other means of detection. specimens include body fluids (e.g., blood, joint fluid, , urine, prostatic secretions, sputum, bronchoal- veolar lavage specimens) wound aspirates swabs of wounds, the throat, nasopharynx, urethra, cervix, or vagina. Blood for culture of mycoplasmas should be collected without anticoagulants and immediately inoculated into an appropriate broth culture medium.
- 25. DIRECT DETECTION METHODS No direct methods for identifying M. pneumoniae, Ureaplasmas spp., or other Mycoplasma spp. although some methods have been described, such as immunoblotting and indirect immunofluorescence. Direct detection by gram staining may rule out the presence of other infectious organisms, but it will not stain cell wall-deficient mycoplasmas and ureaplasmas.
- 26. CULTIVATION the medium for mycoplasma isolation consist of : heart infusion yeast extract salts glucose or arginine horse serum Fetal or newborn calf serum is preferable to horse serum. To prevent the overgrowth of the fast-growing bacteria that usually accompany mycoplasmas in clinical materials. Serum provides fatty acids and cholesterol for mycoplasma membrane synthesis.
- 27. CULTIVATION penicillin, thallium acetate or both are added as selective agents Ureaplasma culture, the medium is supplemented with urea and its pH is brought to 6.0 Ureaplasm a and M genitalium are relatively sensitive to thallium mycoplasma broth and agar and supplemented with glucose and phenol red. . Incubate aerobically for 7 -12 days with 5–10% CO2 at 35-37°C.
- 29. Except for M. pneumoniae colonies which have a granular appearance, described as being mulberry shaped
- 31. on agar, the center of the whole colony is characteristically embedded beneath the surface
- 33. Biochemical test
- 34. SERODIAGNOSIS ELISA tests complement fixation (CF) haemagglutination (HA) immunofluorescence (IF)
- 39. Molecular Methods for rapid laboratory diagnosis such as direct demonstration of organisms in the respiratory specimens by nucleic acid amplification techniques (PCR)
- 40. Treatment The mycoplasmus are sensitive to tetracyclines, macrolids the newer quinolones but are resistant to antibiotics that specifically inhibit bacterial cell wall synthesis.