Mycoplasma

Cards (51)

  • What type of bacteria are mycoplasmas classified as?
    Gram positive bacteria
  • Why do gram-positive bacteria not retain crystal violet stain?
    Because the crystal violet is not stuck in the peptidoglycan
  • What are the two main categories of gram-positive bacteria?
    • Non-spore forming bacteria
    • Lactic acid bacteria: Streptococcus, Lactobacillus, Staphylococcus, Listeria, Mycoplasma
    • Spore forming bacteria: Clostridium, Bacillus
  • What is the GC content characteristic of firmicutes?
    Low GC gram positive bacteria
  • Which group of bacteria is known for having a high GC content?
    Actinobacteria
  • What is unique about mycoplasma in terms of cell structure?
    They completely lack a cell wall
  • How are mycoplasmas related to gram-positive bacteria despite lacking a cell wall?
    Gene sequencing shows they are related
  • What is the effect of osmotic lysis on mycoplasmas?
    They are sensitive to osmotic lysis
  • What strengthens the plasma membrane of mycoplasmas?
    The inclusion of sterols
  • What are lipoglycans in mycoplasmas involved in?
    They help avoid the immune response
  • What is the size range of concord cells?
    0.12 µm to 0.25 µm in diameter
  • Why are mycoplasmas considered pleomorphic?
    Because they come in different shapes
  • What is the significance of mycoplasmas being non-motile?
    Most are non-motile, except some human and animal pathogens
  • What type of organisms do mycoplasmas primarily parasitize?
    Eukaryotes
  • What are the growth factor requirements for mycoplasmas?
    They have complex growth factor requirements due to limited biosynthetic capabilities
  • Which mycoplasmas do not require sterols for growth?
    Acholeplasma, Asteroleplasma, and Mesoplasma
  • How do mycoplasmas appear when grown on solid agar?
    They form a fried egg-shaped colony
  • What is the GC content range for mycoplasmas?
    Approximately 25-35%
  • Which mycoplasma has the smallest known genome?
    Mycoplasma genitalium
  • What is the size of the genome of Mycoplasma genitalium?
    580 kbp
  • How does the genome size of Mycoplasma pneumoniae compare to that of E. coli?
    Mycoplasma pneumoniae has a genome of 816 kbp, while E. coli has 5440 kbp
  • What evolutionary trend has occurred in the genome of mycoplasmas?
    Multiple reductions in genome size have occurred
  • What are the characteristics of mycoplasmas?
    • Require cholesterol
    • Parasites of animal mucous membranes
    • Facultative anaerobes
    • Over 60 species recognized
  • What is the role of urease in mycoplasmas?
    It converts urea to ammonia and CO2
  • What is a common cause of non-gonococcal urethritis (NGU)?
    Mycoplasma genitalium
  • How is Mycoplasma genitalium transmitted?
    By direct venereal contact
  • What is the significance of mycoplasmas in the pharmaceutical industry?
    They are difficult to sterilize in liquids and are common contaminants
  • What is the treatment for Mycoplasma pneumoniae infections?
    Erythromycin, doxycycline, azithromycin, or levofloxacin
  • What complications can arise from Mycoplasma genitalium infections in women?
    Associated with cervicitis and endometriosis
  • What is the recommended treatment for Mycoplasma genitalium in the UK?
    Doxycycline pretreatment followed by azithromycin or moxifloxacin
  • What are the symptoms of Mycoplasma pneumoniae infection?
    • Mild flu-like symptoms: headache, sore throat, cough
    • Severe pneumonia: fever, chills, malaise
    • Protracted course with gradual resolution
  • How is Mycoplasma pneumoniae diagnosed?
    Through clinical symptoms, X-ray, and PCR tests
  • Why are serological tests not commonly used for diagnosing Mycoplasma pneumoniae?
    They are considered old-fashioned and not useful
  • What is the challenge in culturing Mycoplasma pneumoniae?
    Culturing is slow and not very useful
  • Why is accurate diagnosis of Mycoplasma pneumoniae important?
    Because it is resistant to antibiotics that act on the cell wall
  • What antibiotics are ineffective against Mycoplasma pneumoniae?
    Penicillins and cephalosporins
  • What is the role of hydrogen peroxide produced by Mycoplasma pneumoniae?
    It is thought to be responsible for initial cell disruption in the respiratory tract
  • What is the significance of the polar time organelles in Mycoplasma pneumoniae?
    They are involved in specific adhesion to respiratory epithelium cells
  • What is the common age range for individuals affected by Mycoplasma pneumoniae?
    Individuals aged 5-20 years old
  • What type of pneumonia does Mycoplasma pneumoniae cause?
    Primary atypical pneumonia (walking pneumonia)