This is short important review about mycoplasma by Muntadher A. Hawaas

1. Mycoplasmas
(CELL WALL–FREE BACTERIA).

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.

3. classification

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

30. Fried egg colonies

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)

35. Mycoplasms system plus

36. Mycoplasms system plus

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.