Human Microbiome, Disease, and Immunology (#4) Flashcards
the human body is a _______ environment
diverse
microbes regularly found at an anatomical site; associated with HEALTHY body tissue
normal microbiota / microflora
the relationship of microbiota starts at ______
birth
the relationship of microbiota that starts at birth varies with what 2 things?
- environment (vaginal or C-section)
- food source (breast milk or formula)
what bacteria coats baby at birth?
lactobacilli
its good for babies to take some ______ matter in when birthed to get started on their GUT microflora
fecal
where are microflora found?
surfaces of body + at mucous membranes
where are the majority of microbes found on the body?
mucous membranes (sticky + have nutrients)
T/F: mircoflora is normally not found in internal tissues
true (at least not LARGE #s)
C-section babies have a _______% higher chance of getting MRSA in the hospital
30%
C-section babies also have higher rates of ________ and _______
asthma + allergies
microbiota of the human body is a ____________ relationship, where a lot of it is _______
symbiotic; mutualism
every individual has their own microbial _________
fingerprint (“microbial cloud”)
your microbial fingerprint resembles who?
ppl you live with + are close with (they have similar microfola)
T/F: after your establish your microflora at childhood, it’s hard to change
true
different __________ of the body support different microbes
microenvironments
Plasmids are great cloning vectors because:
a) they are larger than the bacteria chromosome
b) they replicate along with the bacterial chromosome
c) they can have multiple copy #s
d) they never carry antibiotic resistance markers
c) they can have multiple copy #s
3 environments of the skin:
- dry skin
- moist skin
- sebaceous skin
environment of the skin: arms + legs
dry skin
environment of the skin: armpit + grown
moist skin
environment of the skin: oily skin; where you get ACNE; back, chest, and nose
sebaceous skin
dry skin has more of what type of bacteria?
gram-POSITIVE
microenvironments of the SKIN resolves around ________
moisture/water
the skin has both _______ and ______ microflora
resident and transient
microflora that just lives there; staph + strep; gram-POS bacteria that can withstand low water environments and some salt
resident
microflora that gets on skin but doesn’t survive; gram-NEG
transient
resident microflora is gram-__________
positive
transient microflora is gram-_________
negative
skin microflora is influenced by __________ and ______ factors
environmental and host
environmental and host factors that affect skin microflora:
- soap
- hygiene
- diet
- hormones
- age
- weather (higher temp = increased moisture)
the skin is an _________ environment
inhospitable
factors why the skin is termed an “inhospital environment”
- mechanically strong barrier
- slightly acidic pH
- high [ ] of NaCl (in sweat)
- many areas low in moisture
- inhibitory substances (lysozyme)
pH of skin =
5.5
example of inhibitory substance of skin:
lysozyme (in sweat)
acne vulgaris + body odor are caused by what bacteria on the skin?
Propionibacterium acnes
clogged pores
acne vulgaris
zits
comedo
______ bacteria make pus
pyogenic
what’s pus made of?
dead WBCs
body odor can be caused by gram-________ bacteria breaking down _______ _______
POSITIVE; fatty acids
ratio of bacteria to human cells
1.3 : 1
avg. human is covered in _____ meters squared of skin
2 meters squared
1 cm squared of skin can have __________ bacteria
1 million
old + young ppl are dirtier so they have more gram-_______ bacteria on their skin
NEGATIVE (bad thing that theyre dirty)
saliva contains antimicrobial enzymes such as ___________, which affect peptidoglycan
lysozyme
microbes colonize on the _______ and _______ in the mouth
teeth + gums
most abundant species of bacteria in the mouth; can make biofilm
Streptococcus spp.
what oxygen requirements does Streptococcus spp. have?
facultative + obligate anaerobes
dental plaque is a _______
biofilm
issues caused by microbes
like Streptococcus spp. in the mouth (4):
- dental plaque
- gental caries
- gingivitis
- periodontal disease
_______ _______ prevents oral disease
mechanical removal (brushing teeth and flossing)
the biofilm, plaque, goes _______ in the middle and produces _______
anoxic; acid
_________ makes filaments that hardens plaque
fussobacterium
another example of antimicrobial enzyme in SALIVA; kills bacteria with singlet oxygen (free radical)
lactoperoxidase
MOST microbes are killed by the _______ conditions of the stomach
acidic
pH of the stomach =
2
how can microbes survive stomach acid (2 ways)?
- pass thru very quickly
- protected by food particles
______ especially protects microbes in the stomach
fat
bacteria that causes stomach ulcers
Helicobacter pylori
has 6 lophotricus bacterium; embeds in epithlium of stomach; makes urease that breaks up urea into CO2 + ammonia
Helicobacter pylori
ammonia produced by Helicobacter pylori _______ stomach acid, protecting bacteria
neutralizes
_________ produced by Helicobacter pylori can be toxic to epithelium cells in the stomach and cause ulcers + lead to stomach cancer
ammonia
how can you detect Helicobacter pylori in your stomach?
ingest liquid and breath – if CO2 then you have it
most ppl have < _____ viable bacteria per mL of gastric fluid
10
_____% of ppl infected with Helicobacter pylori are ASYMPTOMATIC
80%
the decrease in H. pylori has led to an increase in what?
esophageal cancer (bc of increase in acid)
as you move down GI tract and intestines, the pH ________ and the number of bacteria _______
increases; increases
pH of intestines =
7
largest microbial population of body
large intestine (colon)
theres up to ______ microbes / gram of wet weight
10^12
most of the microbes present in the colon are ______ ______
obligate anaerobes
the colon is _______, which is a perfect environment for fermentation
anoxic
species in colon (large intestine - 2)
- Bacteroides
- Clostridiu
colonic bacteria produce (2):
- essential vitamins (B12 and K)
- gas
bacteria make up ______ of the weight of fecal matter
1/3
of bacteria shed each day in feces =
10^13
bacteria in the large intestine are replaced rapidly bc of their ______ _____ ______
high growth rate (1-2 doublings per day)
growth rate of microbes in colon:
1-2 doublings per day
how other parts of the body, like the brain, are affected by the gut
gut-brain axis
gut-brain axis can affect _________
behavior (microbes crave sugar, you eat sugar)
______ ______ are used to treat C. difficil
fecal transplants
what causes C. diff?
strong rounds of antibiotics
opportunisitc bacterium; makes spores, spread in hospitals; releases toxins; can cause pseudo-membranous collitis (blisters in membranes)
C. difficil
fecal transplant is _____% effective in treating C. diff collitis
90%
intestinal microfolra is used to ________ the immune system (ex: Peyers patches)
train
site for immune cells to sample microflora and determine what is good or bad bacteria
Peyer’s Patches
how many Liters of air do we breath in a lifetime that’s filled with dust + microbes?
500 million L
_______ and _______ can live in dust for a long time bc they are resistant to drying
Strep + Staph
since Strep and Staph are gram-________, they are resistant to drying
POSITIVE
1 sneeze can have _______ to _______ bacteria
10,000 - 100,000
each droplet of a sneeze can have how many virions?
1-2
the entire respiratory tract is lined with _______ _______
mucosal membranes
