32 - Microbiota (Normal Flora) Flashcards
what is the basis of all host-pathogen relationships?
the exploitation by one organism (pathogen/parasite) of the environment provided by another (the host)
____________ replicate within the host and multiply to produce a very large number of progeny, causing an overwhelming infection
MICROparasites
____________ progeny usually leave the host to continue the cycle. the level of infection is determined by the numbers of the organisms that enter the body
MACROparasites
What are Koch’s Postulates
The microbe must be present in every case of the disease
the microbe must be isolated from the diseased host and grown in pure culture
the disease must be reproduced when a pure culture is introduced into a non-diseased susceptible host
the microbe must be recoverable from an experimentally infected host
what body areas should be sterile?
Blood
body fluids (CSF, pleural fluid, synovium, pericardial fluid, peritoneal fluid, urine)
tissues (e.g. bone)
typical adult contains ______ “self” cells and about ______ times that many microorganisms
10^13, 10
T/F in health, there is normal microbiota deep in tissues
False
when is the normal microbiota established?
Shortly after birth
Is the normal microbiota essential for life?
no
what kind of organisms benefit from the host without causing harm
commensals
__________ is the presence, growth, and multiplication of bacteria at a specific body site with NO noticeable symptoms
colonization
___________ is the presence and movement of bacteria into a body area (e.g., tissue) with growth and multiplication and NOTICEABLE symptoms (e.g. fever, pus, inflammation
infection
What vitamins can be produced by normal flora organisms
Vit. K & B
how will the normal flora influence the GI tract
stimulate it
what does the normal flora do for the immune system?
general stimulation
T/F Normal flora will produce inhibitory substances to prevent pathogens
True, pathogens are competition for nutrients
what can disturb the intestinal microbiota
any cause of diarrhea
emotional stress
sudden changes in diet
illness- changes in eating and activity
antibiotic therapy
which medication(s) may affect the pt’s microbiota
all of them
what common organisms are present on the skin
staph epidermidis
corynebacterium sp
propionibacterium acnes
where will the microbes be trapped in the respiratory tract
the mucus traps microbes, ciliated epithelium sweeps organisms out
the __________ tract is the primary carriage site of staph aureus
respiratory
what potential pathogens will have transient carriage sites within the respiratory tract
streptococcus pneumoniae
neisseria meningitidis
haemophilus influenzae
ear and sinus infections, pneumonias, meningitis
where is the widest variety of the microenvironments present with humans
the mouth
where is the only site where normal flora routinely causes disease in immunocompentent hosts?
the mouth
what will anaerobes cause in the mouth
perio disease
at what age will streptococci be established in the mouth
4-12 hours after birth
T/F Normal flora in the mouth will break down macromolecules
False, macromolecules don’t stick around long enough, low molecular weight carbohydrates are the ones quickly broken down by normal flora
what will determine what microbiota is present in the mouth
mechanical forces
chemical action of saliva
types of foods consumed
physical consistency of food consumed
what will determine the number of microbiota when looking at the GI tract
the conditions of the organ (e.g. stomach <10 organisms/ml with low pH whereas upper intestines < 10^3/ml)
which organ has the largest population of microbiota in all of the body?
colon (10^10 bacteria per gram of feces)
T/F Colon is primarily anaerobes
true
What are the vaginal microbiota influenced by?
pH (will change at puberty and menopause)
what organism helps keep other organisms out of the vagina during child-bearing years
lactobacilli
