Dynamics of the Host- Parasite Relationships Flashcards
What is mutualism?
One organism initiates and both organisms benefit.
What is commensalism?
1 organisms benefits and the second is neither harmed or benefits
What is parasitism?
one organism benefits and the other is harmed
What are the main benefit to commensal bacteria and yeast?
Colonization resistance and nutrition
What is colonization resistance?
The space is taken up by good bacteria, and there is no space for disease causing bacteria
How can commensal bacteria cause disease?
Commensals belong in particular sites of the body and when they get out of that compartment they can cause disease.
Immunosuppression can increase risk of runaway infections
Where are S. epidermidis and C. albicals found typically?
Skin
What types of bacteria are typically found in the respiratory track?
Wide variety of strep, staph, and Neisseria
What type of bacteria causes plaque and cavities?
S. mutans and other anaerobic bacteria
Does the stomach usually have bacteria?
No, because of the acidity and low pH
What bacteria are typically found in the small intestine?
Strep, lactobacilli, and yeast
What type of respiration do most of the commensals in colon undergo?
Anaerobic mostly
What types of bacteria are typically found in the colon?
Baceroids, Eubacterium, Coliforms, Enterococci, bactovacilli, and clostridium
What system in the human body requres lactobacilli and why?
The GU track needs it for mainenance of a low pH
What causes an increase of pH in the GU track?
An overgrowht of candida (yeast), which is typically a commensal
When a bacteria colonizes a host, how does the host respond?
The adaptive immune system is needed to clear the infection
What are examples of physical barriers of the immune system?
skin, mucus, cilia, nose hair, and cough reflex
What are some examples of chemical barriers of the immune system?
Low vaginal pH, lysozyme, compliment, fever, interferon
What is a paracrine signal?
a cell releases a chemical signal to which its neighbors respond
What is an autocrine signal?
cell responds to its own signal
What is a endocrine signal?
cell releases signals into blood dream to affect distant cells?
What are innate cellular defenses?
Compliment and phagocytosis
Please explain Koch’s postulates
1- observe potential pathogen in sick animal
2- grow a pure culture of the pathogen
3- infect a new animal from the culture
4- observe the same disease in the new animal
5- culture the same potential pathogen from the new animal
Is treatment of a pathogen proof of a pathogen?
No, because it might be susceptible to the drug even if it was identified wrong.
