microbiology- the human microbiome

Question 1

define the human microbiome

Answer 1

microbes that live on and in the human body

Question 2

define the resident microbiota

Answer 2

the organisms normally found in health

Question 3

define colonisation

Answer 3

establishment at a side in the body

Question 4

define symbiosis

Answer 4

two or more organisms co exist in a close physical association

Question 5

define dysbiosis

Answer 5

imbalances in the resident human microbiota or our responses to them

Question 6

define opportunistic infections

Answer 6

infection caused by an organism that is a member of the normal microbiota or normally inhabits the external environment

Question 7

define tissue tropism

Answer 7

propensity for a particular organism to grow on a particular habit

Question 8

give examples of different types of host relationships

Answer 8

parasitism
commensalism
mutualism

Question 9

what is a parasitism relationship

Answer 9

unilateral benefit which has a high degree of damage to the host

Question 10

what is a commensalism relationship

Answer 10

involves one member getting benefits such as food and shelter but the other is unaffected

Question 11

what is a mutualism relationship

Answer 11

reciprocal benefit with a lower degree of damage to the host

Question 12

which relationship does the host community try to maintain

Answer 12

a beneficial relationship

Question 13

give examples of some detrimental relationships

Answer 13

parasitism
amensalism
competition

Question 14

give examples of non sterile sites

Answer 14

GI tract
skin
vagina
conjunctiva

Question 15

what do we mean by non sterilised sites

Answer 15

colonised by normal microbial populations
exposed directly/indirectly to the environment
no mechanism in place to maintain sterility

Question 16

what do we mean by a sterile site

Answer 16

there are no microbes at all

Question 17

what are the three types of sterile site

Answer 17

sterile due to surface cleaning
sterility maintained by barriers allowing one way flow
sterility maintains by physical separation

Question 18

give example of a sterile area which remains sterile due to surface cleaning

Answer 18

lower respiratory tract

Question 19

give examples of a area sterility is maintains due to a barrier which allows one way flow only

Answer 19

by sphincters
eg sphincter of Oddi- hepatobillary tract
middle ear- eustachian tube
upper GI tract- cervix

Question 20

give examples when sterility is maintained from physical barriers

Answer 20

pleural cavities

peritoneal cavity

Question 21

what else do anatomical locations contain

Answer 21

microenvironment 
eg skin 
has toe webs 
scalp
palms

Question 22

what are the early colonisers of the oral microbiota

Answer 22

Strep oralis
S mitis
S salivarious

Question 23

which bacteria can we find in the nasophangeal area

Answer 23

S aureus is found in the nose as a main carrier

Question 24

describe which bacteria we can find in the pharynx

Answer 24

strep pyogenes
H influenzae
strep pneumoniae
S aureus

Question 25

describe bacteria found in the small intestine

Answer 25

higher count of bacteria found in the end of the tract than at the start low pH inhibits growth predominantly facultative anaerobic few/non obligate anaerobes

Question 26

describe bacteria found in the LI

Answer 26

95-99% anaerobes such as bacteriocides and clostridium spp

Question 27

how many organisms are found per gram of stool

Answer 27

10^9-10^11

Question 28

describe clostridium spp

Answer 28

can take over the gut of patients who are already unwell and cause GI issues the patients can have reduced resident microbiota and therefore can only recover when they stop taking antibiotics

Question 29

what is one unusual treatment for c diff

Answer 29

foecal transplant

Question 30

describe microbiota in the vagina

Answer 30

microbiota is similar to skin and lower GI in pre puberty

Question 31

what happens to the bacterial shift in the vagina post puberty

Answer 31

post puberty glycogen is produced due to circulation oestrogen- lactobacillus attracted which uses glycogen to ferment and maintain low pH and prevent overgrowth of species

Question 32

what is the ph of the vagina

Answer 32

3

Question 33

what is the benefits of the resident human microbiota

Answer 33

→ Competitive exclusion of exogenous pathogens → Antagonism of exogenous pathogens → Promotion of normal development of immune system → Promotion of normal human cellular physiology and nutrition → Enhancement of epithelial barrier function, cellular proliferation and would healing responses → Induction of cross reactive antibodies → Modulate immune system to prevent over stimulation

Question 34

when can opportunistic infections occur

Answer 34

``` When there is damage to the epithelia Presence of foreign body Transfer to another site Disturbance of immune system Disruption of resident microbiota Impairment of host responses ```

Question 35

what else can happen to bacteria

Answer 35

it can translocate to another site | eg conjunctivitis- spread from upper respiratory tract infection

Question 36

which bacteria cause caries

Answer 36

streptococcus mutans lactobacillus Actinomyces aggrebacteur

Question 37

which bacteria causes periodontal disease

Answer 37

p gingival tannerella forsythia aggregeribactium actinomycetecomintans spirochetes

Question 38

which bacteria cause aspiration pneumonia

Answer 38

Staphylococcus spp | anaerobes

Question 39

which bacteria cause infection endocarditis

Answer 39

a haemolytic streptococci | staphylococcus

Question 40

which bacteria cause abscesses

Answer 40

streptococci actinomyces spp gram -ve anaerobes

Question 41

which bacteria cause candidiosis

Answer 41

candida spp

Question 42

what are the 6 classes of AMR phenotypes found in the oral microbiome

Answer 42

``` phenicol sulphonamide liconsamide-macrolide streptogramin aminoglycoside tetracycline beta lactam ```