mycoplasma

1. MYCOPLASMAS
BY
ASLAM MATANIA
GROUP-3
FACULTY OF MEDICINE
TSMU

2. INTRODUCTION
• Mycoplasmas are the
smallest free-living
organism in nature
• There are more than
200 known species in
the class of
Mollicutes
• At least 16 of these
species are thought
to be of human origin;
others have been
isolated from animals
and plants

3. In humans, four species are of primary
importance-
• Mycoplasma pneumoniae - respiratory
• Mycoplasma hominis – urogenital;pelvic inflammatory
disease, postpartum fever
• Mycoplasma urealyticum – urogenital
nongonococcal urethritis in men and is
associated with lung disease in premature
infants
• Mycoplasma genitalium is closely related to M
pneumoniae and has been associated with
urethral and other infection

4. CHARACTERSTICS
• Prokaryotic microbes
• Size of 125-250 nm
• Lack of cell wall i.e
resistance to penicilin
• Sterol-containing cell
membrane
• Fastidious growth
• Fried- egg or mulberry
colonies on agar

5. CULTURING
• Mycoplasma can be
cultured on solid or liquid
medium
• Growth optimally at 35
to 37 degree celcius
• Medium of growth
should be enriched with
20% horse and human
serum
• The colonies appears as
fried egg appearance

6. GROWTH CHARACTERSTICS
• Mycoplasmas are unique in microbiology because of
(1) their extremely small size and (2) their growth on
complex but cellfree media
• Mycoplasmas pass through fi lters with 450-nm pore
size and thus are comparable to chlamydiae or large
viruses
• Many mycoplasmas use glucose as a source of
energy; ureaplasmas require urea.
• Some human mycoplasmas produce peroxides and
hemolyze red blood cells

7. ANTIGENIC STRUCTURE
• The surface antigen
are glycolipids and
proteins
• Glycolipids are
identified by
complement fixation
• Protein antigen are
detected by ELISA
method

8. MYCOPLASMA FOUND ON SURFACE OF
MUCOUS MEMBRANE
• MOST OFTEN MYCOPLASMA FOUND ON MUCOUS
MEMBRANE
• THEY CAN CAUSE CHRONIC INFLAMATORRY DISEASIS
OF RESPIRTORY SYSTEM;UROGENITAL TRACT;AND
JOINTS
• THE MOST COMMON HUMAN ILLNESS CAUSED BY
MYCOPLASMA PNEUMONIAE WHICH IS RESPONSIBLE
FOR 10-20% OF ALL PNEUMONIES in 5 to 20 years of
age

9. M. hominis & Ureaplasma species
• Most often associated with urogenital tract
infections
• May be isolated from asymptomatic
individuals
• Can be transmitted to the fetus at delivery
• Opportunistic pathogens

10. Pathogenesis
• Many pathogenic mycoplasmas through droplets which
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 and adherence-accessory proteins
• which influences the protein folding and binding and is
important in the adherence to cells
• The mycoplasmas attach to the surfaces of ciliated and
nonciliated cells, probably through the mucosal cell
sialoglycoconjugates and sulfated glycolipids

11. • Finally these cause direct cytotoxicity
through generation of hydrogen
peroxide and superoxide radicals,
cytolysis mediated by antigen–
antibody reactions or by chemotaxis

12. CLINICAL FINDINGS OF PNEUMONIAE
• Generalized ache and pains
• Fevers(102 degree)
• Cough usually
• Sore throat
• Chills but not rigor
• Nasal congestion
• variety of possible skin lesion
• infection ranges from asymptomatic infection to serious
pneumonitis, with occasional neurologic and hematologic
(ie, hemolytic anemia) involvement

13. • The incubation period varies from 1 to 3 weeks
• The onset is usually insidious
• Other diseases possibly related to M pneumoniae
include erythema multiforme; central nervous
system involvement, including meningitis,
meningoencephalitis, and mono- and polyneuritis;
myocarditis; pericarditis; arthritis; and pancreatitis

14. L Forms
• Some bacteria readily give rise spontaneously to
variants that can replicate in the form of small filterable
protoplasmic elements with defective or absent cell
walls.
• These organisms, called L-forms, can also be formed by
many species when cell wall synthesis is impaired by
antibiotic treatment or high salt concentration.

15. L Forms vs Mycoplasma
• contain a rigid cell wall, at least at
one stage of their life cycle
• no sterols in their cytoplasmic
membrane.

16. • Specimens: throat swab, sputum, genital
secretion, etc.
• Microscopy - This is not particularly useful because of the
absence of a cell wall but it can be helpful in eliminating
other possible pathogens.
• Culture - Sputum (usually scant) or throat washings must be
sent to the laboratory in special transport medium. It may
take 2 -3 weeks to get a positive identification. Culture is
essential for a definitive diagnosis.
• Complement fixation test
• Cold agglutinins - Approximately 34% - 68% of patients with
M. pneumoniae infection develop cold agglutinins.
• ELISA - There is a new ELISA for IgM that has been used for
diagnosis of acute infection.
• PCR
Diagnostic Laboratory Tests

17. • C. Serology-Antibodies develop in humans infected
with mycoplasmas and can be demonstrated by
several methodS
• D. Nucleic Acid Amplification Test-IN THIS primers
and probes ARE USED
• Nucleic acid amplification tests (NAATs) are
particularly useful for those organisms that are
difficult to cultivate such as M pneumoniae and M
genitalium and less useful for the more rapidly
growing organisms

18. Treatment
•Tetracyclines and
erythromycins are
effective