MCB 4403 exam 4 FSU-Zhu correctly
answered already passed
Primary pathogens - correct answer ✔✔Have ability to penetrate host defenses
Opportunistic pathogens - correct answer ✔✔cause disease when the host's defenses are
compromised or when they grow in part of the body that is not natural to them
Human carriers - correct answer ✔✔have inapparent infections or latent diseases
ex: AIDs
Animal carriers - correct answer ✔✔Some zoonoses may be transmitted to humans
ex: rabies, lyme
nonliving infections - correct answer ✔✔found in soil
ex: botulism, tetanus
direct contact - correct answer ✔✔Requires close association between infected and susceptible
host (touching, kissing, sexual intercourse)
indirect contact - correct answer ✔✔fomites (tissues, towels, bedding, diapers, drinking cups,
toys, moneys
,droplet - correct answer ✔✔Transmission via airborne droplets
vehicles - correct answer ✔✔Transmission by an inanimate reservoir (food, water)
Mechanical vectors - correct answer ✔✔Arthropod carries pathogen on feet, eg. flies transfer
pathogens (typhoid fever) from feces of infected to food
bio vector - correct answer ✔✔Pathogen reproduces in vector (Lymes, WNV).
Acute disease - correct answer ✔✔symptoms rapidly
chronic disease - correct answer ✔✔develops slowly
latent disease - correct answer ✔✔disease with a period of no symptoms when the causative
agent is inactive
To cause disease, all pathogens must - correct answer ✔✔Enter a host -
Find their unique niche -
Avoid, circumvent, or subvert normal host defenses -
Multiply and eventually be transmitted to a new susceptible host
"molecular Koch's postulates." - correct answer ✔✔1) The phenotype under study should be
associated with pathogenic strains of a species.
,2) Specific inactivation of the suspected virulence gene(s) should lead to a measurable loss in
virulence or pathogenicity. The gene(s) should be isolated by molecular methods
3) Reversion or replacement of the mutated gene should restore pathogenicity.
pathogenicity islands - correct answer ✔✔contain clusters of virulence genes with specific
functions
Originally inherited through horizontal transmission
Transferred as a block from other organisms
Pili (fimbriae) - correct answer ✔✔Hollow fibrils with tips to bind host cells
Adhesins - correct answer ✔✔surface proteins bind host cells
Biofilms - correct answer ✔✔important role in chronic infections by enabling persistent
adherence and resistance to bacterial host defenses and antimicrobial agents
Toxin - correct answer ✔✔Substances that contribute to pathogenicity
Toxoid - correct answer ✔✔Inactivated toxin used in a vaccine
Antitoxin - correct answer ✔✔Antibodies against a specific toxin
Exotoxins - correct answer ✔✔Proteins produced by various types of bacteria
, Kill host cells and unlock their nutrients
Endotoxins - correct answer ✔✔A part of lipopolysaccharide of Gramnegative bacteria
Can hyperactivate host immune systems to harmful levels
Alpha Toxin - correct answer ✔✔A classic example of a pore-forming exotoxin is the hemolytic
alpha toxin of S. aureus.
Forms a transmembrane, seven-member pore in target cell membranes
Two-Subunit AB Exotoxins - correct answer ✔✔B subunit: binds to host cell
-Delivers A subunit to
cytoplasm
-Often five B subunits form a
pore for A entry.
Diphtheria toxin - correct answer ✔✔Made by Corynebacterium diphtheriae
- Ribosylates elongation factor 2
- Blocks ribosome function; cell dies
- Forms pseudomembrane over trachea
Cholera toxin - correct answer ✔✔Made by Vibrio cholerae
- Ribosylates to overactivate adenylate cyclase
- cAMP activates ion transport; water follows.
- Uncontrollable diarrhea
answered already passed
Primary pathogens - correct answer ✔✔Have ability to penetrate host defenses
Opportunistic pathogens - correct answer ✔✔cause disease when the host's defenses are
compromised or when they grow in part of the body that is not natural to them
Human carriers - correct answer ✔✔have inapparent infections or latent diseases
ex: AIDs
Animal carriers - correct answer ✔✔Some zoonoses may be transmitted to humans
ex: rabies, lyme
nonliving infections - correct answer ✔✔found in soil
ex: botulism, tetanus
direct contact - correct answer ✔✔Requires close association between infected and susceptible
host (touching, kissing, sexual intercourse)
indirect contact - correct answer ✔✔fomites (tissues, towels, bedding, diapers, drinking cups,
toys, moneys
,droplet - correct answer ✔✔Transmission via airborne droplets
vehicles - correct answer ✔✔Transmission by an inanimate reservoir (food, water)
Mechanical vectors - correct answer ✔✔Arthropod carries pathogen on feet, eg. flies transfer
pathogens (typhoid fever) from feces of infected to food
bio vector - correct answer ✔✔Pathogen reproduces in vector (Lymes, WNV).
Acute disease - correct answer ✔✔symptoms rapidly
chronic disease - correct answer ✔✔develops slowly
latent disease - correct answer ✔✔disease with a period of no symptoms when the causative
agent is inactive
To cause disease, all pathogens must - correct answer ✔✔Enter a host -
Find their unique niche -
Avoid, circumvent, or subvert normal host defenses -
Multiply and eventually be transmitted to a new susceptible host
"molecular Koch's postulates." - correct answer ✔✔1) The phenotype under study should be
associated with pathogenic strains of a species.
,2) Specific inactivation of the suspected virulence gene(s) should lead to a measurable loss in
virulence or pathogenicity. The gene(s) should be isolated by molecular methods
3) Reversion or replacement of the mutated gene should restore pathogenicity.
pathogenicity islands - correct answer ✔✔contain clusters of virulence genes with specific
functions
Originally inherited through horizontal transmission
Transferred as a block from other organisms
Pili (fimbriae) - correct answer ✔✔Hollow fibrils with tips to bind host cells
Adhesins - correct answer ✔✔surface proteins bind host cells
Biofilms - correct answer ✔✔important role in chronic infections by enabling persistent
adherence and resistance to bacterial host defenses and antimicrobial agents
Toxin - correct answer ✔✔Substances that contribute to pathogenicity
Toxoid - correct answer ✔✔Inactivated toxin used in a vaccine
Antitoxin - correct answer ✔✔Antibodies against a specific toxin
Exotoxins - correct answer ✔✔Proteins produced by various types of bacteria
, Kill host cells and unlock their nutrients
Endotoxins - correct answer ✔✔A part of lipopolysaccharide of Gramnegative bacteria
Can hyperactivate host immune systems to harmful levels
Alpha Toxin - correct answer ✔✔A classic example of a pore-forming exotoxin is the hemolytic
alpha toxin of S. aureus.
Forms a transmembrane, seven-member pore in target cell membranes
Two-Subunit AB Exotoxins - correct answer ✔✔B subunit: binds to host cell
-Delivers A subunit to
cytoplasm
-Often five B subunits form a
pore for A entry.
Diphtheria toxin - correct answer ✔✔Made by Corynebacterium diphtheriae
- Ribosylates elongation factor 2
- Blocks ribosome function; cell dies
- Forms pseudomembrane over trachea
Cholera toxin - correct answer ✔✔Made by Vibrio cholerae
- Ribosylates to overactivate adenylate cyclase
- cAMP activates ion transport; water follows.
- Uncontrollable diarrhea
