Mycoplasma .pdf

Mycoplasma: intro ,characteristics , properties

1. MYCOPLASMA
SUBMITTED TO :
DR. PRADIP PANWAR
SUBMITTED BY:
MUSKAN SINGHAL
DEPARTMENT OF BIOTECHNOLOGY
CH. CHARAN SINGH UNIVERSITY
M.sc II nd year

2. The mycoplasmas are the simplest self-replicating
prokaryotes.
Mycoplasma is considered as the smallest known
cell of about 0.1 micron (um) in diameter.
First discovered by Pasteur in 1843, as a causal
agent of pleuropneumonia of cattle and called
PPLO.
Later, in 1898 Nocard and Roux, successful
obtained pure culture of these microorganisms in
media.
Mycoplasmas are commonly found in soil, hot
spring, sewage water and also in humans, plants
and animals.
INTRODUCTION

3. CLASSIFICATION
On the basis of their nutritional
requirement.
1. Mycoplasma: They need cholesterol
for their growth.
2.Acholeplasma: They do not need
cholesterol for their growth but will
incorporate it into the membrane if it
gets in the medium.
3. Thermoplasma: They do not require
cholesterol for their growth. Strictly
aerobics

4. Mycoplasma is a genus of bacteria that, like the other members of
the class Mollicutes, lack a cell wall around their cell membranes.
Several species are pathogenic in humans, including M.
pneumoniae, which is an important cause of "walking" pneumonia
and other respiratory disorders, and M. genitalium, which is
believed to be involved in pelvic inflammatory disease
Mycoplasma species (like the other species of the class Mollicutes)
are among the smallest organisms yet discovered,[can survive
without oxygen, and come in various shapes. For example, M.
genitalium is flask-shaped (about 300 x 600 nm)
while M. pneumoniae is more elongated (about 100 x 1000 nm),
many Mycoplasma species are coccoid. Hundreds of Mycoplasma
species infect animals.
TYPES OF MYCOPLASMA

5. CHARACTERISTICS
Smallest free living bacteria
Pass through bacterial filters
Devoid of cell wall
Differ from virus as it has both RNA and DNA.
Requires cholesterol for growth.
Occurs as saprophytic in soil and sewage
Commensal in animals and plants.
Do not possess flagella and pilli. Exhibit gliding motility
Stain poorly with gram strain . Can be strained with Giemsa and Dienes
method.
Mycoplasma are killed by heating at 56C 30 mts .
Antiseptic - certitude, chlorhexidine effective
Resistant to penicillin and cephalosporins
Sensitive toTetracycline and erythromycin.

6. The mycoplasma cell contains a plasma membrane,
ribosomes, RNA, proteins and d circular DNA molecule.
The cell is devoid of cell wall, highly pleomorphic and thus
are called joker of microbiology.
Bounded by trilaminar membrane -sterols lipids.
Taxonomically, the lack of a cell wall is used to separate
mycoplasmas from other bacteria.
They may be ring-like, granular, coccoid, pear- shaped,
filamentous, etc.
Granular forms -coccoid , Ballon disc , ring etc .
Spherical forms - 125-250nm size.
Filamentous forms - 500- 1000nm size , slender branching.
The colonies of mycoplasma have a characteristic round
form with a thickened centre and a delicate periphery like a
fried egg.
They reproduce by vegetative means i.e., by binary fission
and budding.
Structure

7. CULTURE
Aerobes and Facultative anaerobic,except Anaeroplasma
which is strictly anaerobic.
optimum temperature for growth is 35-37C
Require sterol for growth
Enriched media -20% horse serum and 10% yeast extract
Serumprovide cholesterol and fatty acids.
PPLO broth -Enriched media with phenol red as pH
indicator .
Incubate for 48-72 hrs.
Tiny colonies in 48 -72hrs at 37C
In 2 to 6 days - colonies is biphasic

8. DIENES STAIN
Contain azure II, methylene blue , Na2CO3,
benzoic acid and distilled water
Fried Egg Apperance
Cental opaque area extending into the
depth of medium , periphery flat and
translucent.

9. Little leaf disease of brinjal,
Bunchy top of papaya,
Big bud of tomato,
Witches broom of legumes,
Yellow dwarf of tobacco,
Strip disease of sugarcane.
Clover dwarf,
Cotton virescence.
Mycoplasmas are widespread in nature as parasites of humans, mammals, reptiles,
fish, arthropods, and plants.
Plant Diseases:
DIEASES
Pleuropneumonia is caused
by Mycoplasma hominis
Primary a typical pneumonia
is caused by Mycoplasma
pneumonia
Mycoplasma hominis and
Mycoplasma fermentants
infertility in man.
Human diseases:

10. MYCOPLASMA ATTACHES TO RESPIRATORY EPITHELIUM AND
CAUSES LOCAL DESTRUCTION OF TISSUE
IT PRODUCES COMUNITY-ACQUIRED RESPIRATORY DISTRESS
SYNDROME (CARDS) TOXIN
CARDS TOXIN AIDS IN THE COLONIZATION OF MYCOPLASMA
PNEUMONIAE, LEADING TO INFLAMMATION AND AIRWAY
DYSFUNCTION
IT ALSO PRODUCES HYDROGEN PEROXIDE (H2O2), WHICH
CONTRIBUTES TO THE DAMAGE OF RESPIRATORY TRACT CELLS
M . PNEUMONIAE IS A SUPERANTIGEN
MYCOPLASMA CAN ACTIVATE MACROPHAGES ,STIMULATE
CYTOKINE PRODUCTION AND LYMPHOCYTE ACTIVATION.
PATHOGENESIS

11. TRANSMISSION
Transmitted from person to person through
respiratory droplets
M. Pneumoniae is the classic cause of walking
Pneumonia
The disease occurs frequently in young adults ,
military recruits and prisons
DIAGONOSIS
It takes one week for colonies to appear on Eaton
agar .thus it is not used for diagnosis.
Mycoplasma colonies have a fried egg shape
Cold agglutination test can detect the presence
of IgM auto antibodies against RBCs.
Cough in cold with m.pnemonia
PCR and Elisa

12. TREATMENT
Macrolides ( erythromycin and
azithromycin)
Tetracycline (Doxycycline)
Fluroquinolones (i.e. levofloxacin)
These drugs can shorten the
duration of symptom
The disease resolves
spontaneously in 10 to 14 days
Treatment includes