CLS04 - Bacillus and Similar Organisms

  1. What does Columbia CNA stand for?  What is it's use?  Important ingredients?
    • Columbia colistin-nalidixic acid
    • Selective AND differential media
    • For isolation/differentiation of gram +
    • Sheep blood: for hemolysis
    • Colistin and nalidixic acid: selects for gram pos
  2. General bacillus - microscopic appearance? ___robic?  Grows on ____? Disease?
    • Large gram + bacilli in chains ("boxcars"
    • aerobic and facultative anaerobic
    • Grows on BAP, Choc, PEA, blood culture media, nutrient broths
    • Frequent contaminants - diagnose carefully
    • *NOTE - most are sensitive to penicillin
  3. General bacillus - normal environment?  Normally cause disease?
    • Found in soil
    • endospores: highly resistant, remain dormant until deposited in suitable environment for growth
    • Normally disease wild/domestic animals
  4. Bacillus infections acquired by which methods?
    • Traumatic introduction
    • Ingestion
    • Inhalation
  5. Bacillus cereus colonial morphology
    • Large
    • Feathery
    • Spreading
    • HIGHLY B-hemolytic
    • puffy
  6. Bacillus cereus diseases with explanation
    • Food poisoning: mainly rice
    • toxins - hemolysin BL, nonhemolytic enterotoxin, cytotoxin K, cereulide
    • symtpoms within 1-18 hours after ingestion
    • *NHE = darrhea
    • *cereulide = vomiting
    • Wound/eye infections: contamination with soil or foreign body
    • Total blindness after 48 hours (ocular injury)
    • systemic infections for immunocompromised
  7. What bacillus cereus toxins are associated with diarrhea and vomiting?
    • diarrhea: nonhemolytic enterotixin
    • vomiting: cereulide
  8. Bacillus anthracis diseases with information
    • Cutaneous: lesions form on skin
    • most common
    • eschar (necrotic central area) forms in ring of vesicles, heals 1-2 weeks leaving scar
    • 1% fatality rate
    • GI: lesions form in GI tract
    • spores ingested with food
    • lesions in ororpharynx or intestinal tract
    • edema of throat/chest
    • severe nausea/vomiting blood/diarrhea
    • 25-60% mortality (usually toxemia/sepsis)
    • Pulmonary: lesions form in lungs
    • AKA Woolsorter's Disease
    • flulike symptoms - abrupt and severe
    • abnormal chest x-ray, edema, shock, death
    • shock/death within 24-36hrs after symptoms
    • 80%+ mortality
  9. What are the three proteins in anthrax toxin w/ function?
    • Protective antigen (PA): provides entry to your cells
    • Edema Factor (EF): causes influx of liquid to cell
    • Lethal Factor (LF): kills cells
  10. How do you ID bacillus anthracis?  What are the two most important factors?
    • Gram: gram pos rods ("strings of pearls)
    • endospore formation: clear, oval, within rod
    • Culture: nonhemolytic (most other spp are beta)
    • wispy, feathered edges, "medusa head"
    • Direct detection: molecular or antigen-based methods
    • Commercial Biochemical ID systems available
  11. Appearance/reason for use of bacillus anthracis on various culture media
    • SBA: no hemolysis
    • CNA: inhibits gram - (removes contamination)
    • Phenylethyl alochol: inhibits gram - (removes contamination)
    • Bicarbonate agar: induces capsule formation
    • MYP, PEMBA, BCM: isolate B. cereus w/ combo of egg yolk, mannitol, and polymyxin B
    • Chrome agars: colormetric
  12. Therapies for anthrax infection?
    • prophylaxis with ciprofloxacin or doxycylcine recommended after aerial exposure
    • Vaccine available to at-risk individuals (5 doses, annual boosters needed, not pleasant)
  13. What are Brevibacillus and Paenibacillus?
    • Ubiquitous bacteria, usually contaminants
    • Rare opportunistic infections (surgical wounds, meningitis after trauma, pneumonia)
    • RARELY require ID (unless isolated from sterile site)
Card Set
CLS04 - Bacillus and Similar Organisms
CLS04 - Bacillus and Similar Organisms