Microbiology > Normal Flora > Flashcards

Normal Flora Flashcards

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1
Q

what type of microbes are part of our normal flora

A

Implant(always there)
transient
invaders(pathogens)

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2
Q

what is the hygiene hypothesis

A

that decreased microbial exposure in youth predisposes people to autoimmune diseases

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3
Q

how can microbiota alter its habitat

A

-alter pH and oxygen tension
-excrete chemicals
-create barriers(chemical and physical)

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4
Q

characteristics of normal flora

A

-complex mixture(prok/euk/virus)
-differs slightly between individuals
-relatively stable

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5
Q

what can cause fluctuation in normal flora

A

-antibiotics/drugs
-diet/nutrition
-stress
-sleep
-exercise

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6
Q

what is the variability of bacteriophages

A

<5%

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7
Q

what change in normal gut flora is related to IBS

A

decrease in bacterial diversity, increase bacteriophages

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8
Q

how do viruses in NF influence bacterial metabolism

A

they carry genes for CHO metabolism and aa synthesis

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9
Q

T/F the baby is in a sterile environment in the womb

A

FALSE. it contains coliforms

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10
Q

what is the primary microbe in breastfed baby

A

bifidobacterium

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11
Q

what does breast milk contain that is difficult to mimic in formula

A

200+ oligosaccharides

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12
Q

benefits of Bifidobacterium

A

-maintain NF
-reduce serum cholesterol
-synthesis of B complex vitamins(co factors)
-anti tumorigenic

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13
Q

purpose of probiotics

A

reestablish NF after illness/antibiotics

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14
Q

attributes of probiotic bacteria

A

nonpathogenic
no toxin produced
effective
easily cultured
no off flavors

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15
Q

sources of prebiotics

A

inulin, pectin, fiber
-apples
-bananas
-onions
-garlic

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16
Q

what areas of the body have the greatest amount of microbiome diversity

A

mouth and LI

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17
Q

what type of microbe is not found on the skin? why?

A

gram- the skin is diverse in habitats

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18
Q

why are streptococcus and staphylococcus found in most sites

A

they are more resistant to salt

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19
Q

what are the 3 distinct biomes of skin

A

moist
oily
dry

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20
Q

why is skin not desirable for most microbes

A

-periodic drying(ex: showering)
-slightly acidic
-high salt
-lysozyme(breaks NAG and NAM

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21
Q

what microbe on the skin protects the skin? how?

A

P. acnes
produces thiopeptides that block other gram+ bacteria

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22
Q

what is another name for P. acnes

A

cutibacterium

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23
Q

what causes acne during puberty

A

-increased oil in pores lowers O2 levels
-lowered O2 increases P. acne which clogs pores and metabolizes oil into VFAs
-VFAs cause skin inflammation

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24
Q

why was it previously believed that the eye was sterile

A

-blinking, tears, lysozyme

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25
what increases in eyes when there is an infection
Pseudomonas sp.
26
what type of bacteria is seen in the outer ear
similar to whats on skin
27
what bacteria in the middle ear can cause swimmers ear
Pseudomonas aeruginosa
28
why do adults get swimmers ear less often than children
bent in the eustachian tube protects against bacteria from the throat. breast feeding babies can help develop this bend earlier
29
how to organisms in the mouth survive mechanical removal
through adhereing
30
layers of mouth microbiome
1 layer: streptococcus 2 layer: biofilm maturation
31
what are biofilms
community of bacteria that is antibiotic resistance and secretes sticky matrix for attachment
32
what is dental plaque and other dental issues made of
Streptococcus sp.
33
what is quorum sensing
when bacteria reach a threshold number they send chemical signals to "talk" to each other, used in the formation of biofilms
34
what type of flora is found in upper respiratory tract
similar to oral cavity(streptococci)
35
why were the lungs historically thought to be sterile
-continuous stream of mucus -phagocytic activity from macrophages -lysozyme in mucus -sIgA found in body secretions
36
how is bacteria dispersed in lungs
low concentration, in patches/islands
37
what are surfactants? where are they found?
in the lungs to allow movement and act as antimicrobial peptides
38
what happens in the upper respiratory tract when youre drunk
lazy epiglottis: epiglottis stays open, bacteria/fluids can enter the lungs lazy macrophages: dont clear debris
39
how does smoking impact the lungs
destroys cilia, which lowers ability to remove mucus and pathogens, increasing risk of infection
40
what is the risk of HPV infection within your lifetime
>50%
41
how is HPV spread
through skin contact
42
T/F HPV can only be transferred if symptoms are present
FALSE
43
T/F HPV that causes warts often doesnt cause cancer and vice versa
TRUE
44
what is recurrent respiratory papillomatous
HPV that causes warts in the airway, blocks airway, removal causes scarring, frequent removal can lead to tracheostomy and inability to speak
45
why do condoms not protect well from HPV
-dont provide full coverage of skin contact -weakened by creams and spermicides
46
what is found in some vaginal lubricants and acts as a virucide
carrageenan
47
treatment of HPV warts
-freeze off warts -surgical removal
48
how many HPV strains are there? how many infect the genital tract?
approx. 200 strains approx. 40 infect genitals
49
how does gardasil 9 work
it is virus like particles(VLPs) of the spike protein of HPV, gaurds against 90% of cancers
50
what strains of HPV are important to know that gardasil 9 works against
warts: 6, 11 cancer: 16, 18
51
how many doses of the gardasil vaccine do you need
3: 0, 2, 6 months(0 is time of first vaccine) 2: 0 & 6 months
52
why is the female genital tract constantly changing
menstrual cycle causes change in hormone and blood flow
53
what causes a decrease of pH in the vagina? why is this important?
estrogen stimulates glycogen, glycogen fermented by lactobacillus to produce lactic acid. low pH inhibits many bacterial growth
54
impact of close births or premature babies on normal flora
decrease lactobacillus and increase bacterial diversity(bad)
55
why do women typically get UTIs more often than men
urethra is 4x shorter in women, bacteria can reach the bladder more easily
56
most common STI? why?
chlamydia-its almost always asymptomatic
57
what area of the body has the largest microbial populations
large intestine
58
methods of microbial self regulation in the large intestine
-eliminated via peristalsis, desquamation(shedding of intestinal line), and movement of mucus -replaced rapidly due to high reproductive rate
59
what percent of resident flora in the LI are obligate anaerobe? give an example of a microbe that is not?
90% E. coli and yeasts are not
60
how do obligate anaerobes and non obligate anaerobes inhabit the same environment(LI)
very little oxygen gets to the large intestine, what does is quickly used up by the organisms that can use oxygen but dont need it
61
function of normal intestinal flora on exogenous microbes
-compete with exogenous bacteria(space and metabolically) -produce metabolites(acids, antibiotics, ect.) -modify environment(bile and mucus) to increase expulsion of pathogens -decrease pathogen binding by changing host receptors via sugar addition
62
function of normal intestinal flora on host
-aid digestion -contribute vitamin A and K -stimulate GALT for specific immunity -stimulate peristalsis
63
what is GALT
gut associated lymphoid tissue -contains cells needed for immune response
64
causes of leaky gut syndrome
stress toxins food particles drugs pathogens organ malfunction
65
what is leaky gut syndrome
GI inflammation leads to increased permiability and impaired nutrient absorption
66
effects of leaky gut syndrome
food intolerance immune system issues autoimmunity
67
what is referred to as the 2nd brain? why?
NF in gut -interact with receptors -influence brain chemistry -release pharmicologically active molecules through blood
68
effects of strong antibiotics on mental health
antibiotics can increase anxiety and depression
69
impact of antibiotics on microbiome in relation to the brain
5 days of antibiotics can suppress up to 1/3 of gut microbiome which stops growth of new brain cells
69
T/F the vagina typically has high diversity of microbes
FALSE. low diversity, mainly lactobacillus
70
methods of microbial manipulation
-nutrition -antibiotics -microbial supplementation
Microbiology
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