Mycoplasma are the smallest bacteria capable of independent growth and reproduction. They lack cell walls and have unique characteristics compared to other bacteria. Some Mycoplasma species can cause infectious diseases in humans. Mycoplasma pneumoniae causes atypical pneumonia in humans and has a distinctive pear shape with terminal tip organelle. Mycoplasma metabolize carbohydrates and depend on pathways like glycolysis and arginine degradation for energy production. While mostly harmless commensals, some Mycoplasma species have been biologically modified for weaponization, resulting in more deadly forms.
2. General Characteristics
A genus of aerobic to facultative anaerobic bacteria. (family Mycoplasmataceae)
containing gram-negative cells.
They are unicellular, smallest, non-motile and prokaryotic organisms forming fried egg
shaped colonies
They are pleomorphic i.e., able to change their shape depending upon culture media.
They may be rod like, ring like, globoid or filamentous. The filaments are of uniform
diameter (100-300 nm) and vary in length from 3 nm to 150 nm.
Some mycoplasma predominantly assume spherical shape (300-800 nm in diameter).
They are ultra-filterable i.e., they can pass through bacteria-proof filters.
They do not possess rigid cell wall.
The cells are delimited by soft tripple layered lipo-proteinaceous membrane. It is unit
membrane about 10 nm thick.
3. General Characteristics
Within the cytoplasm ribosomes are found scattered in the peripheral zone. These
are 14 nm in diameter and resemble with bacteria in sedimentation characteristic
of both the nucleoprotein and nucleic acid.
The ribosomes are 72S type.
Within the cytoplasm fine fibrillar DNA is present. It is double stranded helix.
Mycoplasma generally grow more slowly than bacteria.
They require sterol for their nutrition.
They are usually resistant to antibiotics like penicillin, cephaloridine, vencomycin
etc. which action cell wall.
They are sensitive to tetracycline.
They are also killed by temperature of 40-55°C in fifteen minutes.
They do not produce spores.
Like other prokaryotes, they usually divide by binary fission.
4. CULTURAL AND BIOCHEMICAL
CHARACTERISTICS
Generally, mycoplasmas are facultative anaerobes, except for Mycoplasma
pneumoniae which is a strict aerobe.
Optimum temperature: 35 - 37°
All mycoplasma except Acholeplasma requires cholesterol or sterol and nucleic
acid precursors for growth
Grow on enrichment media with 20% human or horse serum
Cannot synthesize the component of all membrane by themselves
5. Morphology
Lack a cell wall.
Highly pleomorphic- meaning they don't have true/fixed shape, size or
arrangement. Their shape depends on the environment they are living in.
Size: approximately 0.1 to 0.5 micrometers in diameter.
Require sterols for growth and for membrane systhesis.
Cells are surrounded by a triple layered lipo-proteinaceous unit membrane
which is 10 nm thick. These surface antigens have a potent modulin
activity and are preferential targets of the host immune response.
6. Pathogenic Mycoplasmas
Some species of mycoplasma are non-infectious an out 200 species of mycoplasma
there is just only more than 5 of them can cause infectious diseases. The number of
these pathogenic species in humans is estimated to be fewer than a hundred.
7. Examples of Mycoplasma
Mycoplasma pneumoniae
Mycoplasma hominis
Mycoplasma genitalium
Ureaplasma urealyticum
Ureaplasma parvum
8. Mycoplasma pneumonia
CHARACTERISTICS
They are the smallest organism capable of living and
reproducing on its own.
the absence of a peptidoglycan cell wall and resulting
resistance to many antibacterial agents.
DISEASES
primary atypical pneumonia, tracheobronchitis, and upper
respiratory tract disease.
SYMPTOMS
• your chest pain • sweating • having a sore throat and Head
ache.
Under microscope
On media
9. Mycoplasma pneumonia
Characteristics
These bacteria live in the urinary tract and genitals of about half of
all women and fewer men.
one of the smallest bacteria capable of self-replication, and lacks
the genes coding for the cell wall.
M. hominis is an intracellular gram negative pleomorphic
bacterium, 0.2 to 0.3 µm in diameter.
Diseases
postpartum fever, cesarean section wound infection, pelvic
inflammatory disease, and pyelonephritis
Symptoms
it's discarge in vagina • a pain during urination • vaginal itching
Under microscope
On media
10. Mycoplasma genitalium
CHARACTERISTICS
You get this if you have sex with someone who's infected.
Is a type of bacteria that can cause an STD.
is one of the smallest prokaryote capable of replication, lacks
a cell wall and has a characteristic pear/flask shape with a
terminal tip organelle
M. genitalium has several virulence factors that are
responsible for its pathogenicity.
DISEASE
nongonococcal urethritis
Symptoms
• Vaginal itching. •Burning with
Under microscope
11. Ureaplasma urealyticum
Characteristics
a bacterium that is found in the urogenital tracts of humans.
It stains gram negative, but that is because it lacks a cell wall.
Ureaplasma can spread during sex
Ureaplasma is a very small bacterium that both men and
women can catch and transmit to each other.
Ureaplasma infection is a little known but common STI.
DISEASE
nongonococcal urethritis
SYMPTOMS
• it hurts when you pee • You're belly pain • it is pain, odor or
discharge from the vagina.
Under microscope
On media
12. Ureaplasma parvum
CHARACTERISTICS
was formerly known as Ureaplasma urealyticum biovar 1.
has been identified as being a commensal in the uterus as
part of the microbiome in healthy women of reproductive age.
Disease
STI or STD
Brain Ventriculitis
Symptoms
• Discharge from urethra • its sweeling at the opening of
urethra
Under microscope
Under microscope
13. Metabolism
Mycoplasma
pneumoniae
can metabolize a range
of carbohydrates that
feed into glycolysis
ending in pyruvate,
which is catabolized by
several enzymes.
Mycoplasma
hominis
can grow on glucose agar
medium giving fried egg
colonies within 24 to 48
hours. It’s energy
metabolism is dependent
on arginine degradation
while other mycoplasmas
don’t have this
characteristics.
Mycoplasma
genitalium
genitalium
is deficient in many
genes coding for
components of many
biosynthetic pathways,
including energy
metabolism. M.
genitalium depend
mostly on glycolysis for
the production of ATP,
which is less efficient
than oxidative
phosphorylation.
14. Metabolism
Ureaplasma urealyticum
We examined the effect of 31
carbohydrates on the growth of
Ureaplasma urealyticum and Mycoplasma
hominis. Arbutin and its breakdown
product, hydroquinone, inhibited growth
of both species; the other substrates did
not alter the extent of growth. Volatile
and nonvolatile end products of
carbohydrate metabolism were not
detected by gas chromatography.
Ureaplasma parvum
parvum metabolism is very streamlined
when compared to Plasmodium. The
absence of mitochondria genes suggests
that this parasite relies on glycolysis as
the source of energy production. C.
parvum is capable of taking up and
catabolizing monosugars such as glucose
and fructose.
15. Uses of Mycoplasma
Positive uses of Mycoplasma
Scientist used the same mycoplasma to develop disabling diseases like MS,
Crohn’s colitis, Lyme disease.
Negative uses of Mycoplasma
Pathogenic mycoplasma was biologically modified and use as a weapon.
The pathogenic Mycoplasma used to be very innocuous, but biological
warfare research conducted between 1942 and the present time has resulted
in the creation of more deadly and infectious forms of Mycoplasma.
Researchers extracted this mycoplasma from the Brucella bacterium and
actually reduced the disease to a crystalline form. They “weaponised” it and
tested it on an unsuspecting public in North America
16. Mycoplasma mobile- Morphology,
Multiplication and gliding Motility
Rosengarten, Renate; Kirchhoff, Helga: Mycoplasma mobile - Morphology, Multiplication and Gliding Motility. IWF. 1986. https://doi.org/10.3203/IWF/C-1670eng