Gram + bacteria

• What alternative name is given to Mycoplasma?

  Mollicutes
• Why are Mycoplasma referred to as "soft skinned"?

  Because they completely lack a cell wall and possess only a plasma membrane
• How do Mycoplasma stain in Gram staining?

  They stain Gram negative
• To which group are Mycoplasma phylogenetically related?

  Low GC Gram positives (Firmicutes, Lactobacillus-Clostridium branch)
• What is the consequence of Mycoplasma lacking a cell wall?

  They are sensitive to osmotic lysis
• What strengthens the plasma membrane of Mycoplasma?

  Inclusion of sterols
• What does it mean that Mycoplasma are pleomorphic?

  They have variation in the size and shape of cells
• What is the size range of coccoid Mycoplasma cells?

  0.12µm - 0.25µm in diameter
• Why are Mycoplasma hard to remove from tissue culture growth medium?

  Because of their small size and ability to squeeze into different shapes
• What type of organisms are all Mycoplasma?

  Parasites of eukaryotes
• What is a characteristic feature of Mycoplasma colonies on solid agar media?

  They often appear as fried egg shaped colonies
• What is the genome size of Mycoplasma genitalium?

  580 kbp
• What is significant about the genome of Mycoplasma genitalium?

  It has the smallest known genome of any self-replicating organism
• How many genera are recognized within the Mycoplasmas?

  Several genera
• What is the habitat of Mycoplasma species?

  Parasites of animal mucous membranes
• What is the growth requirement for Ureaplasma?

  Requires cholesterol and urea for growth
• What is the association of Ureaplasma with human health?

  May be associated with nongonococcal urethritis
• What type of bacteria is Acholeplasma?

  Widely distributed animal parasites that can grow in absence of sterols
• Where do Anaeroplasma inhabit?

  Inhabit bovine or ovine rumen
• What type of bacteria is Spiroplasma?

  Helical and motile parasites on arthropods and plants
• What disease does Mycoplasma pneumonia cause?

  Respiratory tract infection leading to primary atypical pneumonia
• How is Mycoplasma pneumonia diagnosed?

  By patchy diffuse X-Ray, serological tests, or culture
• What type of antibiotics are used to treat Mycoplasma pneumonia?

  Antibiotics that do not target the cell wall, such as erythromycin and doxycycline
• What are the genital Mycoplasmas associated with?

  Non-gonococcal urethritis and infertility in men
• How is detection of genital Mycoplasmas typically performed?

  Using molecular techniques like PCR
• What is the treatment for genital Mycoplasmas?

  Doxycycline, erythromycin, and/or azithromycin
• What is the significance of Mycoplasma penetrans?

  It infects humans in the urogenital and respiratory tracts and is associated with HIV infection
• How do Streptococci cells divide?

  They divide only in one plane, forming chains
• What type of media do Streptococci require for growth?

  Complex media
• What is a characteristic feature of Streptococci regarding catalase?

  They are unable to make catalase
• On what type of agar are Streptococci grown?

  Blood agar
• What are the three groupings of Streptococci based on hemolysis?

  • β - complete hemolysis -> clear zone
  • α - incomplete hemolysis -> greenish-brown zone
  • γ - no hemolysis
• What are the Lancefield Groups of β-hemolytic Streptococci based on?

  • Named after Rebecca Lancefield
  • Based on specific carbohydrate antigen extracted by heating cells to 150°C
  • Groups A, B, C, D, etc.
• What is the predominant species in Group A Streptococci?

  Streptococcus pyogenes
• What is the significance of M-proteins in Group A Streptococci?

  They provide sub-classification into over 100 sub-serotypes
• What diseases can Group A Streptococci cause?

  Strep throat, impetigo, cellulitis, necrotizing fasciitis, and scarlet fever
• What causes scarlet fever in relation to Group A Streptococci?

  It is caused by a pyrogenic toxin-producing organism
• What are the symptoms of scarlet fever?

  Fever, susceptibility to endotoxic shock, and erythematous rash
• What is rheumatic fever and its association with Group A Streptococci?

  It occurs after an untreated pharyngeal infection and affects joints and heart
• What is glomerulonephritis and its association with Group A Streptococci?

  It occurs after a Strep infection and affects the kidneys