Micro of Animals

Question 1

commensals

Answer 1

microorganisms found on the bodies of healthy animals/people

• residents ( skin, mouth, colon)
• can do no harm, be beneficial or be parasitism

Question 2

disease vs infection

Answer 2

disease= damage or injury to the host that impairs host function 
infection= situation in which microorganism is established and growing in a host, causing damage

Question 3

pathogenicity

Answer 3

the ability of a parasite to inflict damage to host

Question 4

virulence

Answer 4

measure of pathogenicity

Question 5

opportunist pathogen

Answer 5

causes disease only in the absence of normal host resistance

Question 6

phylogenetic studies suggest that herbivory has evolved _____ in many different lineages

Answer 6

independently

Question 7

GIT of herbivores

Answer 7

live on plants – cellulose and other insoluble polysaccharides

• lack the enzyme cellulase
• microorganisms degrade cellulose and other fiber to give host nutrients (mutualism) in either hind or fore gut

Question 8

2 digestive stragegies have evolved in herbivorous animals

Answer 8

• foregut fermentation: fermentation chamber precedes (comes before) the acidic stomach
• Hindgut fermentation: uses cecum and large intestine as fermentation chambers

Question 9

foregut fermentors

Answer 9

ruminants, monkeys

- fermentation chamber before stomach

Question 10

handgun fermetors

Answer 10

rabbits, horses

- fermentation chamber after the small intestine

Question 11

the rumen of ruminant animals

Answer 11

rumen- foregut fermentation chamber in ruminant animals

food is chewed minimally, swallowed and passes to rumen

Question 12

rumen condition in cows

Answer 12

100-150L
39-40 degrees
5-7 pH
anaerobic environment (fermentation)

Question 13

how is pH in rumen maintained

Answer 13

by saliva which contains sodium bicarbonate

Question 14

only a small proportion of the microorganism in the rumen produce ______. and as such fermentation is mediated by?

Answer 14

cellulases.

mediated by cellulytic microbes which break down cellulose into glucose and cellobiose (then available to all other microbes)

Question 15

sugars in gut get fermented by microbes and produce?

Answer 15

volatile FA: acetic acid, propionic acid, butyric acid

methane and CO2

Question 16

where do the FA pass and what are they used for?

Answer 16

through the rumen wall and into the bloodstream and used as the animals main energy source

Question 17

overall stiochiomentry of rumen fermentation

Answer 17

57 glucose–> [65 acetate, 20 propionate, 15 butyrate] + 60 CO2, 35 CH4 and 25 H2O

Question 18

which ones are the rumen microorganisms?

Answer 18

Ciliated protozoa, bacteria, archaea, methanogens (300-400 species)

Question 19

Methanogens

Answer 19

strict anaerobes that produce methane from H and CO2 or acetate (CH3COOH)

Question 20

acetate used by methanogens is not available to the ___

Answer 20

host

Question 21

up to ___ % of energy value of the feed can be lost as CH4

Answer 21

10%

Question 22

what compound is added to feed to reduce CH4 production

Answer 22

Monensin (inhibits methanogenesis)

Question 23

explain what happens after several hours in the rumen

Answer 23

small portions are regurgitated, well chewed and then res wallowed. other portions get collected by the reticulum and moved to the omasum, where execs water is collected. then material goes to stomach (abomasum)

Question 24

the mass of microbial cells that grow on the food are subjected to digestion, bc they then pass onto the small intestine and serve as a major source of ?

Answer 24

AA and vitamins

are tis the ones that were in the rumen?

Question 25

what happens with non-ruminant herbivores

Answer 25

no rumen, so fermentation happens in the caecum

Question 26

the microbial mass that grows on the cellulose are not digested, they are___-

Answer 26

excreted

Question 27

what is the difference in ruminant herbivory and non-ruminant in terms of dietary requirements?

Answer 27

non-rum need more AA and vitamins ---> bc microbial mass is not digested in non-rum - rabbits get around this by eating their faecal matter

Question 28

termites- anoxic environment in gut

Answer 28

decompose cellulose and hemicellulose | - have diverse anaerobic bacteria and celluloyti protists

Question 29

Cefdinir

Answer 29

antibiotic to treat infection-- produced int body?? after cow milk start in babies??

Question 30

epimeric is composed of

Answer 30

living inner layer, dead outer c=layer

Question 31

Sebaceous glands, apocrine sweat glands

Answer 31

secrete sweat and salt- secretion are slightly acidic and have antimicrobial properties

Question 32

dead layer

Answer 32

prevents micro penetration

Question 33

ducts that carry secretions are colonize by only a select few ___ species

Answer 33

gram - positive

Question 34

normal microbiome secretes

Answer 34

bacteriocin

Question 35

Actinobacteria

Answer 35

51 % gram-p on skin

Question 36

teeth consist of

Answer 36

mineral (enamel) surrounding living tissue (dentin and pulp)

Question 37

how do bacteria colonize tooth surfaces

Answer 37

attach to acidic glycoproteins deposited there by saliva

Question 38

streptococcus mutans

Answer 38

lots of growth of microorganisms (especially streptococcus) result in dental plaque. In the presence of sugar, streptococcus mutant synthesize extracellular polysaccharides(dextran) that aid in the attachment to the tooth surface--> form an ECM (extracellular matrix)

Question 39

as plaque begins to grow____ bacterial species grow

Answer 39

anaerobic

Question 40

the various microorganisms plaque---> S. mutant and various lactobacilli- ferment sucrose and process

Answer 40

lactic acid that demineralizes the tooth enamel ( solubilizes calcium )

Question 41

microorganisms in the human colon are mostly

Answer 41

strict anaerobes or facultative aerobes: bactericides, enteric bacteria, yeast, anaerobic protoza

Question 42

methanogens are found in ___ of humans intestine tract

Answer 42

1/3

Question 43

what are responsible for the smell in GIT

Answer 43

organosulfur compounds (methanethiol)

Question 44

intestinal microorganisms benefit the host by producing

Answer 44

- ferment VFA --> produce gas CO2 and H2 | AA, Vitamins B, K, thiamine riboflavin

Question 45

obese mice had more ___

Answer 45

methanogens - high H2 retards fermentation ( in lean mice) - low H2 promotes fermentation in obese mice (more VFA and nutrients to host??) this is bad???

Question 46

3 common in respiratory tract

Answer 46

streptococci, staohyoccocci and cornyebacteria

Question 47

lower res track was once considered??

Answer 47

free of microorganisms | - now not the case, but still low biomass

Question 48

genitourinary tract and urinary tract are generally free of microorganism due to flushing of

Answer 48

urine

Question 49

Hormones control the ____ concentration of the vaginal epithelium

Answer 49

glycogen concentrations

Question 50

microorganism degrade glycogen and produce ____

Answer 50

and produce lactic acid which reduces the pH of the vaginal tract tot 4.5

Question 51

when are glycogen levels highest in the vaginal tract

Answer 51

sexually mature - acidic environment

Question 52

main microbial flora that differs in sexual active female in the vaginal tract

Answer 52

lactobacilli---> make lactic acid -- lowers pH

Question 53

steril zones

Answer 53

``` blood, spinal fluid gut cavity (peritoneal cavity Pleural cavity sinuses interior region of body tissues ```