Gram Postive Rod

  1. What are some Gram postive rods
    Bacillus, Clostridium, Corynebacerium, Lactobacillus, and Mycobacterium
  2. Name a distinction of Bacillus and its key pathogens
    • Distinction: Catalase positive, endospores(aerobically)
    • Key pathogen: Bacillus anthracis=Anthrax
    • Bacillus cereus=food poisoning
  3. Name distinction of Clostridium and Key pathogen
    • Distinction: Obligate anaerobes, catalase negative
    • Key pathogen: Clostridium tetani=deep cut, neurotoxin
    • Clostridium botulinium=Neurotoxin, botox
  4. Name a distinction of Corynebacterium and a key pathogen
    • Distinction: Catalase positive, Normal flora of human skin, no spore
    • Key Pathogen:
    • Corynebacterim diphtheriae=Diphtheria
  5. Name a distinction of Lactobacillus and key pathogen
    • Distinction: Microaerophilic with fermentative metabolism, catalase negative, oxidase negative
  6. What is the main distinction of MYCOBACTERIUM and its key pathogen?
    • Distinction: weakly Gram-positive curved or straight rods, catalase positive, no endospore, aerobic
    • Key pathogen: Mycobacterium tuberculosis=tuberculosis
    • Microbacterium leprae=leprosy
  7. How to diagnose tuberculosis that was caused by Mycobacterium tuberculosis?
    Acid fast stain of sputum sample, chest x-ray, tb skin test
  8. What is Acid-fast stain?
    It is a differential stain used to differentiate acid fast organisms that contain mycolic acids in cell walls
  9. What do we call acid fast bacteria? why are they so special?
    • Actinomycete genera
    • These are more resistant to decolorization by an acid-alcohol solution
  10. What is mycolic Acid?
    • Waxy substance in acid-fast cell that increase affinity for primary stains Carbol Fuchsin and repel typical aqueous stain
    • Usually weakly gram-positive
  11. What is the primary stain used in Acid-fast stain?What are the options for counter stain?
    • Primary stain=Carbol fuchsin
    • Counterstain=Malachite Green or methylene blue
  12. What is the main acid-fast bacteria and how does it appear on the slide?
    Main one is Mycobacterium and it appear to be pinkish red. weakly gram positve. appear red due to the primary stain and the other type of cell is stain with the counter stain.
Card Set
Gram Postive Rod
Gram positive rod