Mycoplasma / Mollicutes

Question 1

What is another name for Mycoplasma? what does the name mean?

Answer 1

• Mollicutes
• Soft skinned, (mollis = soft, cutis = skin)

Question 2

What does Mycoplasma / Mollicutes lack?

Answer 2

• Cell wall

Question 3

Does Mycoplasma stain gram positive or negative? why?

Answer 3

• Stain gram negative
• Lack of cell wall and only possess a plasma membrane

Question 4

Lack of cell wall means they are sensitive to what?

Answer 4

• Osmotic lysis

Question 5

What is in the plasma membrane ?

Answer 5

• Sterols

Question 6

What does Sterols do to the plasma membrane?

Answer 6

• strengthen the plasma membrane

Question 7

What is meant when Mycoplasma is stated as pleomorphoic?

Answer 7

• they have variation in the size and shape of cells - big, small, long, branched…

Question 8

How is Mycoplasma pleomorphoic?

Answer 8

• No cell wall so shape is varied

Question 9

True or false Mycoplasma are the smallest living cells?

Answer 9

• True

Question 10

What is the diameter of Mycoplasma?

Answer 10

• 0.12 micro m - 0.25 micro m

Question 11

How are Mycoplasma common contaminants in tissue culture?

Answer 11

• small size allows them to squeeze into different shapes and spaces.
• makes them hard to remove from tissue culture growth medium and animal products by filtration

Question 12

Mycoplasma are parasites of what?

Answer 12

• Eukaryotes

Question 13

What does Mycoplasma require to facilitate growth in lab media

Answer 13

• They require sterols

Question 14

What do Mycoplasma resemble when looked at on solid agar media

Answer 14

• fried egg shaped colonies

Question 15

Does Mycoplasma have large or small genomes?

Answer 15

• Small genomes

Question 16

What is the amount of DNA of mycoplasma?

Answer 16

• Close to the smallest amount of DNA capable of encoding a free-living cell

Question 17

What is Mycoplasma?

Answer 17

• Genus of bacteria
• Parasite of animal mucous membranes
• Over 60 species recognised

Question 18

What is Ureaplasma?

Answer 18

• Genera
• (T-Strain Mycoplasma) - microaerophilic
• Require cholesterol and urea for growth
• Maybe associated with nongonococcal urethritis

Question 19

What is Acholeplasma?

Answer 19

• Genera
• Widely distributed animal parasites
• Able to grow in absence of sterols
• Common contaminants of cell lines in tissue culture

Question 20

What is Anaeroplasma?

Answer 20

• Genera
• Strict anaerobes
• Inhabit bovine or ovine rumen

Question 21

What is Spiroplasma?

Answer 21

• Genera
• Holical, motile
• Parasites on arthropods and plants (e.g. citru stubborn and corn stunt diseases), but a few cause disease in animals

Question 22

Name some important human pathogen Mycoplasma species

Answer 22

• Mycoplasma pneumonia
• Genital Mycoplasmas
• Mycoplasma penetrans

Question 23

Give an outline of Mycoplasma pneumonia

Answer 23

• Human pathogen species
• respiratory tract infection
• Diagnosis by pathchy diffuse X-Ray, serological tests or culture
• Treatment is with antibiotics that do not target the cell wall
• Treatments include Erythromycin, doxycycline ( not children), azithromycin

Question 24

Give an outline of Genital Mycoplasmas

Answer 24

• Human pathogen
• Mycoplasma genitalium.
• Causes of non-gonococcal (non-chlamydial) urethritis NGU
• associated with infertility in men
• associated with cervicitis and endometritis and tubal factor infertility in women
• Treated with doxycycline / erythromycin and/or azithromycin
• Drug resistance is rising

Question 25

Give an outline of Mycoplasma penetrans

Answer 25

• Infects humans in the urogenital and respiratory tracts
• Penetrates into human cells, intracellular replication adn persistence for months/years
• Associated with HIV infection