1.1 normal flora

Question 1

symbiont?

Answer 1

organism that lives in close physical association with the body

ex. lactobacillus

Question 2

pathobiont?

Answer 2

potentially pathogenic organism which under normal conditions lives as a symbiont (potential pathogen)

ex. e.coli

Question 3

commensal?

Answer 3

organism always present at an area of the body

organism benefits, host neutral

Question 4

pathogen?

Answer 4

organism that can cause disease

ex. HIV (never ignore because they always cause harm if infected)

Question 5

virulence factors?

Answer 5

factors that help organisms cause disease/avoid immune response

ex. toxin production

Question 6

normal flora/microbiota?

Answer 6

bactera/fungi typically found in certain areas in the body

if found elsewhere, may cause disease

Question 7

normal flora of oral cavity?

Answer 7

streptococcus pneumoniae

Question 8

normal flora of nasal cavity?

Answer 8

viridans streptococci

Question 9

normal flora of vagina?

Answer 9

lactobacillus spp.

Question 10

normal flora of skin?

Answer 10

staphylococcus epidermus/aureus, corynebacterium spp.

Question 11

normal flora of gut?

Answer 11

bacteroides fragilis, e.coli, enterococci spp., klebsiella pneumonia

Question 12

points of entry?

Answer 12

mucous membranes

defense: have normal flora to prevent colonization of pathogens

Question 13

skin microbiome?

Answer 13

gram + bacilli and cocci

staph. aureus (can be coagulase positive and more virulent)

staph
coryneform
propionibacterium

Question 14

respiratory tract microbiome?

Answer 14

upper
- staph spp.
- strep. pneumoniae
- haemophilus spp.
- anaerobes

lower
-sterile

Question 15

GI microbiome?

Answer 15

fewer gram+
enterococci (resistant to bile)

upper
- facultative aerobes

lower
- anaerobes
- enterococcus
- psudomonas
- enterobacteriacae (e.coli, klebsiela, enterobacter)
- streptococcus
- lactobacillus
- candida

Question 16

urogenital tract microbiome?

Answer 16

bladder = sterile

distal third of urethra
- lactobacillus
- streptococcus

Question 17

female urogenital microbiome?

Answer 17

prepubescent + postmenopausal = similar to skin

mid-years
- lactobacillus (produces lactic acid + prevents bacterial vaginosis)

Question 18

benefits of normal flora?

Answer 18

maintain healthy GI

confers resistance to colonization by pathogens

antioxidant activity

aids in biosynthesis of vitamins and AA

aids in metabolism of therapeutics

anti-inflammatory

supports host-defence

regulates CV system

Question 19

clinical benefits of normal flora?

Answer 19

reduce cancer risk

role in effectiveness of anticancer therapy (beneficial dysbiosis improves therapy)

CF (altered respiratory and gut microbiome = susceptible to colonization)

IBD/Crohn’s disease (dysbiosis allows for colonization, leads to inflammation)

prevents colonization of pathogens (non-pathogenic microbiota occupy attachment sites

Question 20

benefits of the GI microbiome?

Answer 20

regulate bone mineralization

develop immune system

provides substrates for metabolism

provide amino acids

Question 21

GI microbial by-products?

Answer 21

microorganisms take in nutrients from food and produce by-products

by-products
- short chain FAs (SCFAs)
- microbe-associated molecular patterns (MAMPs)

Question 22

effects of SCFAs and MAMPs on health

Answer 22

maturation of lymphocytes

regulates gut epithelium tone

increased neuroendocrine signaling (energy and appetite)

activation of pattern recognition receptors (PRRs) and GPCR mediated signalling