Bacterial Pathogenesis & Zoonoses Flashcards
What is Germ or Contagion Theory?
Infection spread by random contacts BETWEEN infected and susceptible people (or animals)
Koch’s Pustulates definition
- Proving that a specific organism is causative to a species disease
- In simple terms:
You find the suspect (the germ), make sure it’s guilty (by making someone sick), and then prove it was there all along (by finding it again). That’s Koch’s postulates!
Koch’ Postulates steps (4)
- Isolated organism from disease, but not from a healthy animal.
- Growth of pure culture of organism.
- Introduce organism to susceptible animals.
- Re-isolated organism from susceptible animals.
Normal flora
T/F: Body of a healthy fetus is sterile in the uterus (AKA no flora)
True!
After they are born they become exposed to their natural flora through their mother and environment.
Symbiosis
Living together in harmony
Mutual
Relationship benefits both organism and host
Commensal
Relationship benefits one, but has no affect on the other
Pathogen is ____ to the host
The relationship hurts/harmful to the host
Microbial Antagonism
Belief that normal flora protect host from growth of pathogens (ex. vagina)
Symbiosis
Benefit of relationship to both host and organism (ex. rumen)
Normal flora: Skin (3)
- Bacteria
Staphylococcus epidermidis (on the skin)
Propionibacterium acnes (on hair follicles)
Corynebacterium species (skin surface) - Fungi
Malassezia species (on skin)
Candida species (yeast-like on skin) - Viruses
There are various viruses. EX:
Bacteriophages (reg bacterial populations)
Normal flora: Intestines (2)
DOUBLE CHECK
- Bacteroides - high numbers.
- Enterobacteriaceae (E coli) - low number
Normal flora occur where? (6)
- Mouth & nose
- Conjunctiva (eye area)
- Urethra
- Vagina
- Prepuce
- Rumen/cecum
Biofilm
Community of microorganisms adhered on surface.
“City of bacteria with different cultural backgrounds”
EX: plaque on teeth
Sterile body regions (organism free) (3)
- Lower respiratory tract (trachea, lungs)
- Upper urinary tract (bladder kidneys)
- Upper reproductive tract (uterus, prostate)