prokaryotes and animal health

Question 1

3 types of symbiotic associations

Answer 1

commensalism, mutualism, parasitic/pathogen

Question 2

commensalism

Answer 2

one benefits, one neither benefits nor is harmed

Question 3

mutualism

Answer 3

both benefit

Question 4

parasitic/ pathogen

Answer 4

one benefits, one is harmed

Question 5

pathogen

Answer 5

microorganism that is able to produce disease/ disrupt the normal physiology of the host

Question 6

opportunistic pathogen

Answer 6

normally a commensal that can become pathogenic when gains access to abnormal location

Question 7

obligate pathogen

Answer 7

requires host to fulfill its lifecycle

Question 8

normal flora aka indigenous microbiota

Answer 8

bacteria and microbes that are consistently associated w animals

Question 9

why might a commensal become an opportunistic pathogen and cause infection

Answer 9

lowered defence mechanisms, (immunosuppressed), normal flora disturbed (antibiotics), change in natural habitat of organism (wound)

Question 10

how does fusobacterium necrophorum become opportunistic pathogen

Answer 10

commensal in the rumen but when transferred to liver becomes pathogen and causes hepatic accesses

Question 11

what is the rumen

Answer 11

large pre-gastric fermentation chamber in order to digest fibrous plant materials such

Question 12

pathway of the rumen

Answer 12

fiber, starch, sugars, protein via microbial fermentation become volatile fatty acids (VFAs) and methane, CO2 and water

Question 13

VFAs in the rumen

Answer 13

volatile fatty acids are released when plant material is broken down
animal uses VFAs as its primary source of energy

Question 14

microbes in the rumen

Answer 14

grow and increase in number and wash through to the lower tract as primary protein source

Question 15

negative interactions in the rumen

Answer 15

predation, pathogens and competition for space and resources

Question 16

E coli as mutualism

Answer 16

synthesizes vitamin K in intestine, essential for blood clotting, assists in food absorption and waste processing, in exchange large intestine provides nutrients necessary for survival

Question 17

infection

Answer 17

growth of microorganisms in/on tissues of the host

Question 18

inflammation

Answer 18

response if host tissue to injury or infection, infiltration of tissue with WBCs, redness, swelling, pain

Question 19

invasiveness;

Answer 19

ability of a microorganism to enter body and spread

Question 20

disease

Answer 20

injury to host that impairs the function of host tissue

Question 21

pathogenicity

Answer 21

the capacity of a bacterium to cause disease

Question 22

virulence

Answer 22

the degree/ severity of disease caused, related directly to the infectious agent

Question 23

pathogenesis

Answer 23

mechanism of infection

Question 24

how microorganisms cause disease

Answer 24

exposure, adherence to skin of mucosa, invasion through epithelium, colonization and growth; disease

Question 25

see disease in three ways

Answer 25

hypersensitivity, invasiveness or toxicity

Question 26

adhesins

Answer 26

fimbriae, pili, surface proteins

Question 27

invasins

Answer 27

intimim, exotoxins

Question 28

exotoxins

Answer 28

peptides mostly secreted by gram positive bacteria, cytotoxins, haemolysins, proteases, phospholipids, leukocidins

Question 29

endotoxins

Answer 29

only in gram neg bacteria, released when bacteria killed, LPS, pryogenic, toxic shock

Question 30

siderophores

Answer 30

iron sequestration

Question 31

antimicrobial resistance

Answer 31

no longer affected by action of antimicrobial, grave and growing global problem

Question 32

intrinsic resistance AMR

Answer 32

microorganism has structural or functional characteristics which provide AMR

Question 33

acquired resistance AMR

Answer 33

genetic mutations or acquisition of genetic elements, the resistance we actually worry about

Question 34

enterotoxigenic E.coli

Answer 34

diarrhea in calves, lambs, pigs and humans, causes rapid dehydration and acidosis

• virulence factors for : colonization (adhesins, siderophores) and disease causation (enterotoxins)

Question 35

Enterohaemorrhagic E.coli

Answer 35

• In animals and when ingested by humans can make you sick
• Non-fimbrial adhesion, protein punches way into intestinal cell and adhere
• Destructs epithelial cell → blood in feces
• Also produces sugar toxin that can get into bloodstream, targets kidneys and brain → kidney failure and oedema in brain

Question 36

bacillus anthracis (anthrax)

Answer 36

• Disease usually associated with herbivores (sheep, goats, cattle) occasionally pigs, humans
• Human infection; spores inhaled, or cutaneous infection or ingested
• Needs two things to cause disease; capsule and exotoxin
• Capsule; prevent phagocytosis
• Exotoxin; oedema and tissue damage
• Capsule+toxin = death

Question 37

botulism; clostridium botulinum

Answer 37

• ingestion of toxin on decomposing plant or animal material –> disease
• botulinum toxin (neurotoxin)
• acts peripherally at neuromuscular junction
• prevents release of acetycholine from synapsis
• causes paralysis

Question 38

two diseases declared eradicated

Answer 38

rinderpest and small pox

Question 39

uropathogenic e coli

Answer 39

example of opportunistic pathogen when it gets into urinary tract