Unit 2 Symbionts of Humans Flashcards
The total of all microbes living in and on the human body
The human microbiome
What forms microbe habitat areas on the skin?
Oil glands and hair follicles
How do microbes/bacteria types found on the skin help with disease prevention?
Crowding out harmful competitors
What aspect of oils harms toxins?
What other things of the skin affect toxins
Fatty acids are toxic
Salt concentration
This term means tolerant of high salt concentrations
Halotolerant
Is the pH of the skin basic or acidic?
Are there more or less nutrients?
Is it wet or dry?
This is a hostile environment
Acidic
Less nutrients
Dry
What type of bacteria is commonly seen in the outer layersof skin?
Gram positive
What type of bacteria is seen in the inner layers of the skin?
Gram negative
Do the contents of our skin remain the same throughout our lives?
No. Changes as we age (puberty) because chemical content of sweat changes.
Why do gram positives occupy the of the skin?
What do gram negatives occupy inner layers?
It’s dryer
They need moisture to maintain outer membrane
What type of environment is the vagina?
How is this different from the skin?
What does the mucous do?
Where is mucous found?
Mucous Membrane
One layer of metabollically active cells with mucous on top of it.
Traps microbes
Places that have openings to the surrounding environment
Microbial populations in the vagina are affected by…
- Proximity to the skin and anus
- pH of the vaginal tract
- Moisture levels
- Age
Common symbionts in the vagina include Lactobacillus acidophillus Staphylococcus epidermidis E. coli and Enterococcus faecalis Candida spp. (a yeast organism)
Where is each commonly found? They migrate from other places
Staphylococcus epidermis in the SKIN
Lactobacillus acidophillus, E.coli, and enterococcus faecalis are in DIGESTIVE tract
Candid spp. (Yeast) is found everywhere
Is vagina conducive for the growth of microbes?
What prevents growth?
Yes. Nutrients, sugars, etc. are found there. The slight acidity effects it.
What microbe ferments the sugar and produces lactic acid in the vagina to drop the pH? Happens after hormonal changes
It protects against other type of microbes and lessens the amount of
Lactobacillus acidphillus
Yeast
What can disrupt normal flora of vagina?
Antibiotics lower lactobaccillus population and increase pH, yeast are unaffected.
Yeast infection aaahhhh!
What can combat yeast infections when women are on antibiotics? It has lactobaccillus
Yogurt!
What area of the body is second of colonization only to the colon?
Why?
The Oral Cavity
Warm, moist, rich in nutrients from saliva and food
There have been over 700 bacterial species detected in the mouth, what is analyzed to decide what kind of microbe it is?
Over half of them cannot be cultured
rRNA gene analysis
Is the inside of our mouth aerobic or anaerobic?
Anaerobic. Near the surface is not.
Buildup of what is a major cause of cavities and periodontal disease?
Do we ever get rid of plaque 100%, even after visiting the dentist?
Plaque biofilm
Nope.
Is enamel easy for microbes to attach to?
What can it attach to which coats our teeth?
No, very slippery
Proteins in the saliva
What is the protein from saliva and bacterial components that microbes attach to in the mouth called?
Pellicle
A biofilm is a layer of
microbes
Microbes associated with plaque in teeth are associated with plaque in arteries. What can this contribute to?
Cardiovascular Disease.
What sugar gives cavities?
What is it made of?
What breaks down sucrose?
What does it make glucose into?
What happens to fructose?
Sucrose
Glucose + fructose
Simutans
Capsule
Fermentation –> Lactic Acid
What process causes cavities, metabolism of glucose or fructose?
Fructose because of lactic acid produced
Is the bacteria in the gut uniform among humans?
Does the type of bacteria change in different places in the gut?
Very different
In can depend upon diet, genetics, etc
Yes.
What produces acid components of intestines when it lowers?
How do they live there?
Bacterial flora
The digestive tract is more anaerobic as you proceed, increases chances of fermentation
Don’t memorize table on symbionts of the digestive tract!
Don’t waste your time!
What category of cells are methane producers?
Archea
The lining of the digestive tract is what type of membrane
Do the microbes of the gut attach to the human tissue?
What occurs, then?
Is there an exception?
Mucous Membrane
Not usually
They form a biofilm along the mucus that lines the intestines
Pathogenic microbes do attach to tissues
If a microbe can get passed the mucous layer, what usually occurs?
We eject the bacterial flora/membrane via vomiting or diarrhea , etc
Thus taking anti-diarrheal medication can be a bad thing under certain circumstances
What are 3 benefits of the microbe symbiont relationship to humans?
Some produce vitamins that we absorb
Some assist in digestion of materials in food prior to absorption (we couldn’t digestion certain things without them)
They assist in proper immune function
How do microbes assist in immune system function?
Crowding out pathogens
Priming the immune system
Keeping the immune system in balance after routine exposure
These are live microbes that when ingested, may provide a beneficial effect to the human body
Are they effective?
Probiotics
Results of studies on their effectiveness vary widely
Where might probiotics be beneficial?
Lactose Intolerance, antibiotic induced diarrhea, childhood illness related diarrhea.
Why can’t many people have a milkshake but can have yogurt?
Probiotics
Why is it beneficial to take probiotics with antibiotics, specifically?
C diff. (bacteria) is unaffected and can spread without competition
What else can be done to help with diarrhea, etc, induced by antibiotics that doesn’t go away over time and can’t be helped by probiotics?
Fecal transplant. Feces from other people can be purified and delivered to the colon.
