L9_Dynamics of the Host-Parasite Relationship Flashcards
Our relationship with most of our normal flora is best described as?
Commensalism
What are the most common skin commensals, which is the most dangerous opportunistic pathogen?
Staph epidermidis, Candida Albicans, and Staph Aureus. If not contained properly, staph aureus will cause disease (i.e. broken skin)
What does commensalism on the skin assume?
The skin is not broken
What does commensalism in the Respiratory Tract Assume?
The host is immunocompetent
What are the most common commensals in the Nose and Throat? Which species can cause problems if over grown?
Wide variety of commensals including Strep, Staph, and Nisseria. Problems with overgrowth of S. Pyogenes, N. Meningitidis, and S. Aureus
What commensal in the mouth can cause cavities and heart valve disease if hygiene is poor? Name two other commensals in the mouth
S. Mutans….Actinomyces (causes that buldge along the chin) and Kingella Kingae
Describe the colonization of the stomach, small intestine and large intestine.
Stomach usually free of bacteria, small intestine has strep, lactobacilli, and yeast, and the large intestine is totally full of a large variety which are mostly anaerobes (coliforms).
Name two examples of true symbiotes
Nutrient generating bacteria in gut and Lactobacillus in the vagina
How do commensals contribute to the innate immune system?
Colonization resistance
Describe the steps of Koch’s Postulate.
Observe disease, culture pathogen, infect new host, observe same disease, culture same pathogen.
What does lactobacillus help do in the vagina?
Keep a low pH
What type of overgrowth can happen in vagina if pH rises?
Candida (yeast infection)
What is a danger to neonates from mothers commensals if delivered vaginally without antibiotics?
Group B strep (sepsis and Meningitis)
Also S. Aureus
Why is it difficult for most species to colonize on the skin?
Acid pH, Dry
List the chemical components of the innate immune system
Acid pH on skin, stomach, and vagina
lysozyme
Defensisns
