10 ppt

• False colour transmission electron micrograph of Mycoplasma sp, (red particles) at the surface of an animal cell (yellow)

  
• Taxonomy of the Class Mollicutes
• Mycoplasma


  Parasitic (requires cholesterol for synthesis of plasma membrane)<|>Nonparasitic (doesn’t require sterol)
• Mycoplasma is originally known as “Pleuropneumonia-like organisms (PPLOs)”

  
• Mycoplasma are the smallest free living prokaryotes
• Mycoplasma can survive extracellularly and are found in several plants & animals
• Mycoplasma are unique among bacteria because they have no cell wall
• Characteristics of Mycoplasma

  • Pleomorphic
  • Spherical or pear shaped to filamentous with branching
  • Resistant to beta-lactams
  • Lack of a reaction to Gram stain
• Facultative anaerobes


  Growth is better aerobically
• Mycoplasma colonies on solid media have a fried egg appearance
• Mycoplasma pneumoniae


  aka Eaton agent<|>Colonizes the mucosa of the respiratory tract
• Causes of Mycoplasma pneumoniae

  • Primary atypical pneumonia/walking pneumonia
  • CAP & tracheobronchitis in children & young adults
  • Extrarespiratory manifestations
• Extrarespiratory manifestations of Mycoplasma pneumoniae

  • Hemolytic anemia
  • Arthritis
  • Acute glomerulonephritis
• Mycoplasma pneumoniae is most frequently found in persons aged 5–20 years
• Determinants of Pathogenicity for Mycoplasma pneumoniae

  • Gliding motility
  • P1 protein
  • Hydrogen peroxide and superoxide
  • Filamentous, flexible form
• Gliding motility helps penetrate through respiratory secretions
• P1 protein is for attachment of M. pneumoniae to host cells
• Hydrogen peroxide and superoxide injure mucosal cells, causing ciliostasis and sloughing of superficial cells
• Filamentous, flexible form facilitates localization in crypts and folds and between microvilli and cilia, where it is protected from phagocytosis
• Acceptable specimens for laboratory diagnosis of Mycoplasma pneumoniae


  • Body fluids
  • Tissues
  • Wound aspirates
  • Swabs of wounds
  • Throat
  • Nasopharynx
  • Urethra
  • Cervix
  • Vagina
• Laboratory diagnosis methods for Mycoplasma pneumoniae

  • Serologic tests
  • Cold Agglutination Reaction
  • CF
  • ELISA
• Culture of Mycoplasma pneumoniae is clinically non-contributory
• Culture media for Mycoplasma pneumoniae

  • SP-4 Mycoplasma medium
  • Shepard’s
  • A7B
  • Edward-Hayflick agar (E-agar)
• Calcium alginate and Dacron swabs are used for sample collection
• SP4 is a transport medium for Mycoplasma pneumoniae
• Definitive identification of Mycoplasma pneumoniae involves overlaying suspicious colonies with 0.5% guinea pig RBC on PO4-buffered saline
• Genital Mycoplasma species

  • Ureaplasma urealyticum
  • Ureaplasma parvum
  • Mycoplasma hominis
  • Mycoplasma genitalia
• Ureaplasma spp. are found colonizing the vagina and cervix in 40%–80% of adult women
• Ureaplasma spp. cause urinary calculi and nongonococcal urethritis (NGU)
• Vaginal colonization with genital mycoplasmas in pregnant women is not associated with disease
• Presence of mycoplasma in placental membranes or amniotic fluid is associated with chorioamnionitis, preterm birth, and several neonatal disorders
• Clinical manifestations of Mycoplasma hominis

  • Postpartum fever
  • Postabortal fever
  • Pelvic inflammatory disease (PID)
  • Pyelonephritis
• Clinical manifestations of Mycoplasma genitalia

  • Linked to NGU in males only
• Laboratory diagnosis methods for genital Mycoplasma

  • Recovered from urethral, vaginal, or endocervical swab specimens
  • Blood
  • Urine
  • Abscess material
  • Prostatic secretions
  • Semen
  • Tissues
• Culture media for genital Mycoplasma

  • Shepard’s A7-B agar
  • U (Ureaplasma) agar/broth
• No commercial serologic assays are available for genital mycoplasmas
• Use of serology for genital mycoplasmas is confined to research
• Manganese Chloride Urea Test is a rapid identification test for U. Urealyticum
• The reaction for the Manganese Chloride Urea Test is observed under a dissecting microscope
• A positive result for the Manganese Chloride Urea Test shows a dark brown precipitate of manganese oxide around colonies