lec 1-2 intro and human microbiome

Question 1

effect of microbes on water

Answer 1

drinking water can become polluted e.g. oestrogen from contraceptive pill

Question 2

what are the challenges against eradication of disease

Answer 2

intracellular infections
multiple host organisms
genetic plasticity

Question 3

antigenic drift

Answer 3

mechanism for variation in viruses involving accumulation of mutations within the genes that code for antibody-binding sites.

point mutations hemaglutinin and/or neuraminidase genes, encoding envelope glycoproteins

Question 4

antigenic shift

Answer 4

process by which two or more different strains of a virus, combine to form a new subtype having a mixture of the surface antigens of the two or more original strains.

genetic reassortment of genome segments between animal/bird and human strains

Question 5

why should we not eradicate infection?

Answer 5

co-evolution is ongoing and natural 
co-metabolism 
community stability 
cost
environmental contamination

Question 6

emerging infectious diseases

Answer 6

have not occured in humans before

occured previously but only small isolation populations affected

Question 7

gnotobiotic

Answer 7

microbe free

Question 8

microbiota

Answer 8

microorganisms that inhabit a specific environment

Question 9

microbiome

Answer 9

all the microbes, their genomes and environmental interactions in a defined environment

Question 10

dysbiosis

Answer 10

microbial imbalance in or on the body

Question 11

co-evolution hypothesis

Answer 11

between humans and microbes

microbes have been around for millions more years

Question 12

why is diversity in gut flora important

Answer 12

allows the natural system the potential to cope with imbalances and change without artificial involvement e.g. antiobiotics

Question 13

role of gut microbes

Answer 13

immune system regulation
removing toxins
crowding out pathogens
improving intestinal function
gut-brain links?

Question 14

how does hygiene affect microbe populations

Answer 14

increased hygiene in living conditions causes loss in microbe populatons - not there to protect against infection

clean water, c-section, antibiotics

Question 15

why do babies microbiota differ

Answer 15

c-section or birth canal delivery

different mothers microbiota

Question 16

where are microbes likely to be found in the body

Answer 16

internal tissues

- they are constantly exposed to environmental microorganisms and are readily colonised by diverse microbial species

Question 17

conditions of skin affecting types of microbes found

Answer 17

pH
salinity
temperature

Question 18

HMP

Answer 18

human microbiome project

characterisation of whole microbial communities

Question 19

ethical issues of HMP

Answer 19

• selection of research participants
• informed consent
• data sharing and privacy
• invasiveness of sample
• how findings are returned to participants

Question 20

microbiome analysis

Answer 20

DNA analysis
culture independent sequence analysis
reduce bias
- few microbes can be grown in labs

Question 21

16s RNA sequencing

Answer 21

all bacteria have 16s ribosomes

that sequence is same in all bacteria

Question 22

metagenome sequencing

Answer 22

whole genome shotgun sequencing of the microbiome

Question 23

microbial reference genome

Answer 23

catalogue of 3000 genes to be created

phylogenetic tree of 16s similarities