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Mcb2010 final

STUDY
PLAY
Pathology
The study of a disease. it deals with etiology,pathogenesis and effect of disease on body
Etiology
Study of caude of disease
pathogenesis
development of disease
Infection
colonization of the body by pathogens( a pathogen invading your body)
An infection is not always caused by a disease
disease
abnormal state in which the body is not functioning normally. It is what comes after an infection
transient microbiota
may be present for days, weeks, or months
(visitor they come and go)
Normal microbiota
permanently colonize the host
Symbiosis
relationship between normal microbiota and the host
Commensalism
one organism benefits, and the other is unaffected
Mutualism
both organism benefit ex E. coli
parasitism
one organism benefits at the expense of the other
Microbial Antagonism
competition between microbes
Normal Microbiota protect the host by
occupying niches that pathogens might occupy
producing acids producing bacteriocins
Probiotics:
live microbes applied to or ingested into the body, intended to exert a beneficial effect ex lactos bacillus
Koch postulates
The same pathogen must be present in every case of the disease
The pathogen must be isolated from the diseases host and grown in pure culture
The pathogen from the pure culture must cause the disease when it is inoculated into a healthy, susceptible lab animal
The pathogen must be isolated from the inoculated animal and must be shown to be the original animal
...
...
Endemic disease
...
Symptom
A change in body function that is felt by a patient as a result of disease
Sign
A change in a body that can be measured or observed as a result of disease
Syndrome
A specific group of signs and symptoms that accompany a disease
Communicable disease
A disease that is spread from one host to another
Contagious disease
A disease that is easily spread from one host to another
Noncommunicable diseas e:
A disease that is not transmitted from one host to another
Incidence
Fraction of a population that contracts a disease during a specific time
Prevalence
Fraction of a population having a specific disease at a given time
Sporadic disease
Disease that occurs occasionally in a population
Endemic disease
Disease constantly present in a population
Epidemic disease
Disease acquired by many hosts in a given area in a short time
Pandemic disease
Worldwide epidemic
Herd immunity
Immunity in most of a population
Acute disease
Symptoms develop rapidly
Chronic disease
Disease develops slowly
Subacute disease
Symptoms between acute and chronic
Latent disease
Disease with a period of no symptoms when the causative agent is inactive
Local infection
Pathogens are limited to a small area of the body
Systemic infection
An infection throughout the body
Focal infection
Systemic infection that began as a local infection
Sepsis
Toxic inflammatory condition arising from the spread of microbes, especially bacteria or their toxins, from a focus of infection
Bacteremia
Bacteria in the blood
Septicemia
Growth of bacteria in the blood
Toxemia
Toxins in the blood
Viremia
Viruses in the blood
Primary infection
Acute infection that causes the initial illness
Secondary infection
Opportunistic infection after a primary (predisposing) infection
Subclinical disease
No noticeable signs or symptoms (inapparent infection)
Make the body more susceptible to disease
Short urethra in females
Inherited traits, such as the sickle cell gene
Climate and weather
Fatigue
Age
Lifestyle
Chemotherapy
Contact Direct
Requires close association between infected and susceptible host
Indirect
Spread by fomites
Droplet
Transmission via airborne droplets
Vectors
Arthropods, especially fleas, ticks, and mosquitoes
Vectors Transmit disease by 2 general methods
Mechanical transmission: Arthropod carries pathogen on feet
Biological transmission: Pathogen reproduces in vector
Nosocomial Infections
Are acquired as a result of a hospital stay
Affect 5-15% of all hospital patients
Emerging Infectious Diseases
Diseases that are new, increasing in incidence, or showing a potential to increase in the near future
Emerging Infectious Diseases Contributing factors
Genetic recombination
E. coli O157, avian influenza (H5N1)
Evolution of new strains
V. cholerae O139
Inappropriate use of antibiotics and pesticides
Antibiotic-resistant strains
Changes in weather patterns
Hantavirus
Modern transportation
West Nile virus
Ecological disaster, war, and expanding human settlement
Coccidioidomycosis
Animal control measures
Lyme disease
Public health failure
Diphtheria
Epidemiology
The study of where and when diseases occur
Morbidity
Incidence of a specific notifiable disease
Mortality
Deaths from notifiable diseases
Morbidity rate
Number of people affected in relation to the total population in a given time period
Mortality rate
Number of deaths from a disease in relation to the population in a given time
Which one of the following does NOT contribute to the incidence of nosocomial infections?
A) Formation of biofilms
B) Lapse in aseptic techniques
C) Gram-negative cell walls
D) Lack of handwashing
E) Lack of insect control
c
Which of the following is NOT a communicable diseases?
A) Malaria
B) AIDS
C) Tuberculosis
D) Tetanus
E) Typhoid fever
d
Koch's postulates don't apply to all diseases because
A) Some microorganisms can't be cultured in laboratory media.
B) Some microorganisms don't cause the same disease in laboratory animals.
C) Some microorganisms cause different symptoms under different conditions.
D) Some microorganisms can't be observed.
E) Not all diseases are caused by microorganisms
e
The graph in Figure 14.3 shows the incidence of polio in the United States. The period between 1945 and 1955indicates
A) An endemic level.
B) An epidemic level.
C) A sporadic infection.
D) A communicable disease.
E) A pandemic
b
Which of these infections can cause septicemia?
A) Bacteremia
B) Focal infection
C) Local infection
D) Septicemia
E) Systemic infection
b
A cold transmitted by a facial tissue is an example of
A) Direct contact.
B) Droplet transmission.
C) Fomite.
D) Vector.
E) Vehicle transmissio
c
Which of the following pairs is mismatched?
A) Malaria - vector
B) Salmonellosis - vehicle transmission
C) Syphilis - direct contact
D) Influenza - droplet infection
E) All of these are correctly matched
e
8. A nosocomial infection is
A) Always present but is inapparent at the time of hospitalization.
B) Acquired during the course of hospitalization.
C) Always caused by medical personnel.
D) Only a result of surgery.
E) Always caused by pathogenic bacteria.
b
9. Which of the following can contribute to postoperative infections?
A) Using syringes more than once
B) Normal microbiota on the operating room staff
C) Errors in aseptic technique
D) Antibiotic resistance
E) All of these
e
Pseudomonas bacteria colonized the bile duct of a patient following his liver transplant surgery. This is an example of a
A) Communicable disease.
B) Latent infection.
C) Nosocomial infection.
D) Sporadic disease.
E) None of these.
c
The science that deals with when diseases occur and how they are transmitted is called
A) Ecology.
B) Epidemiology.
C) Communicable disease.
D) Morbidity and mortality.
E) Public health.
b
12. Mechanical transmission differs from biological transmission in that mechanical transmission
A) Doesn't require an arthropod.
B) Involves fomites.
C) Doesn't involve specific diseases.
D) Requires direct contact.
E) Doesn't work with noncommunicable diseases
c
Emergence of infectious diseases can be due to all of the following EXCEPT
A) Antibiotic resistance.
B) Climatic changes.
C) Digging up soil.
D) Microbes trying to cause disease.
E) Travel
d
During a 6-month period, 239 cases of pneumonia occurred in a town of 300 people. A clinical case was defined as fever 39°C lasting >2 days with three or more symptoms (i.e., chills, sweats, severe headache, cough, aching muscles/joints, fatigue, or feeling ill). A laboratory-confirmed case was defined as a positive result for antibodies against Coxiella burnetii. Before the outbreak, 2000 sheep were kept northwest of the town. Of the 20 sheep tested from the flock, 15 were positive for C. burnetii antibodies. Wind blew from the northwest, and rainfall was 0.5 cm compared with 7 to 10 cm during each of the previous 3 years.


In Situation 14.1, the etiologic agent of the disease is
A) Sheep.
B) Soil.
C) Coxiella burnetii.
D) Pneumonia.
E) Wind.
c
One effect of washing regularly with antibacterial agents is the removal of normal microbiota. This can result in
A) Body odor.
B) Fewer diseases.
C) Increased susceptibility to disease.
D) Normal microbiota returning immediately.
E) No bacterial growth because washing removes their food source.
c
A sexually transmitted disease is an example of
A) Direct contact.
B) Droplet transmission.
C) Fomite.
D) Vector.
E) Vehicle transmission
a
Which of the following diseases is NOT spread by droplet infection?
A) Botulism
B) Tuberculosis
C) Measles
D) Common cold
E) Diphtheria
a
A needlestick is an example of
A) Direct contact.
B) Droplet transmission.
C) Fomite.
D) Vector.
E) Vehicle transmission
c
Symptoms of disease differ from signs of disease in that symptoms
A) Are changes felt by the patient.
B) Are changes observed by the physician.
C) Are specific for a particular disease.
D) Always occur as part of a syndrome.
E) None of these.
a
Influenza transmitted by an unprotected sneeze is an example of
A) Direct contact.
B) Droplet transmission.
C) Fomite.
D) Vector.
E) Vehicle transmission.
b
A commensal bacterium
A)

Does not receive any benefit from its host.
B)

Is beneficial to its host.
C)

May be an opportunistic pathogen.
D)

Does not infect its host.
E)

B and D only.
E
2)

Which of the following statements is true?
A)

Symbiosis refers to different organisms living together.
B)

Members of a symbiotic relationship cannot live without each other.
C)

A parasite is not in symbiosis with its host.
D)

Symbiosis refers to different organisms living together and benefiting from each other.
E)

At least one member must benefit in a symbiotic relationship.
...A
3)

A nosocomial infection is
A)

Always present but inapparent at the time of hospitalization.
B)

Acquired during the course of hospitalization.
C)

Always caused by medical personnel.
D)

Only a result of surgery.
E)

Always caused by pathogenic bacteria.
...B
4)

The major significance of Koch's work was that
A)

Microorganisms are present in a diseased animal.
B)

Diseases can be transmitted from one animal to another.
C)

Microorganisms can be cultured.
D)

Microorganisms cause disease.
E)

Microorganisms are the result of disease.
...D
5)

Koch's postulates don't apply to all diseases because
A)

Some microorganisms can't be cultured in laboratory media.
B)

Some microorganisms don't cause the same disease in laboratory animals.
C)

Some microorganisms cause different symptoms under different conditions.
D)

Some microorganisms can't be observed.
E)

All diseases aren't caused by microorganisms.
...E
6)

Which of the following diseases is not spread by droplet infection?
A)

Botulism
B)

Tuberculosis
C)

Measles
D)

Common cold
E)

Diphtheria
...A
7)

Mechanical transmission differs from biological transmission in that mechanical transmission
A)

Doesn't require an arthropod.
B)

Involves fomites.
C)

Doesn't involve specific diseases.
D)

Requires direct contact.
E)

Doesn't work with noncommunicable diseases.
...C
8)

Which of the following definitions is incorrect?
A)

Endemic a disease that is constantly present in a population
B)

Epidemic fraction of the population having a disease at a specified time
C)

Pandemic a disease that affects a large number of people in the world in a short time
D)

Sporadic a disease that affects a population occasionally
E)

None of the above
...B
9)

Which of these infections can cause septicemia?
A)

Bacteremia
B)

Focal infection
C)

Local infection
D)

Septicemia
E)

Systemic infection
C
10)

Which type of infection can be caused by septicemia?
A)

Bacteremia
B)

Focal infection
C)

Local infection
D)

Septicemia
E)

Systemic infection
...E
11)

Koch observed Bacillus anthracis multiplying in the blood of cattle. What is this condition called?
A)

Bacteremia
B)

Focal infection
C)

Local infection
D)

Septicemia
E)

Systemic infection
...D
12)

Nosocomial infections are most often caused by
A)

Escherichia coli.
B)

Staphylococcus aureus.
C)

Enterococcus.
D)

Pseudomonas.
E)

Klebsiella.
...C
13)

Transient microbiota differ from normal microbiota because transient microbiota
A)

Cause diseases.
B)

Are found in a certain location on the host.
C)

Are acquired by direct contact.
D)

Are present for a relatively short time.
E)

None of the above.
...D
14)

Which of the following statements about nosocomial infections is not true?
A)

They occur in compromised patients.
B)

They are caused by opportunists.
C)

They are caused by drug-resistant bacteria.
D)

They are caused by normal microbiota.
E)

None of the above.
...E
15)

One effect of washing regularly with antibacterial agents is the removal of normal microbiota. This can result in
A)

Body odor.
B)

Fewer diseases.
C)

Increased susceptibility to disease.
D)

Normal microbiota returning immediately.
E)

No bacterial growth because washing removes their food source.
...C
16)

Which of the following is not a reservoir of infection?
A)

A sick person
B)

A healthy person
C)

A sick animal
D)

A hospital
E)

None of the above
...E
17)

All of the following are communicable diseases except
A)

Malaria.
B)

AIDS.
C)

Tuberculosis.
D)

Tetanus.
E)

Typhoid fever.
...D
18)

Which of the following is a fomite?
A)

Water
B)

Droplets from a sneeze
C)

Pus
D)

Insects
E)

A hypodermic needle
...E
19)

All of the following statements about biological transmission are true except
A)

The pathogen reproduces in the vector.
B)

The pathogen may enter the host in the vector's feces.
C)

Houseflies are an important vector.
D)

The pathogen may be injected by the bite of the vector.
E)

The pathogen may require the vector as a host.
...C
20)

Which of the following definitions is incorrect?
A)

Acute a short-lasting primary infection
B)

Inapparent infection characteristic of a carrier state
C)

Chronic a disease that develops slowly and lasts for months
D)

Primary infection an initial illness
E)

Secondary infection a long-lasting illness
...E
21)

Symptoms of disease differ from signs of disease in that symptoms
A)

Are changes felt by the patient.
B)

Are changes observed by the physician.
C)

Are specific for a particular disease.
D)

Always occur as part of a syndrome.
E)

None of the above.
...A
22)

The science that deals with when diseases occur and how they are transmitted is called
A)

Ecology.
B)

Epidemiology.
C)

Communicable disease.
D)

Morbidity and mortality.
E)

Public health.
...B
Figure 14.1





24)

Emergence of infectious diseases can be due to all of the following except
A) Antibiotic resistance.
B)

Climatic changes.
C)

Digging up soil.
D)

Microbes trying to cause disease.
E)

Travel.
...D
25)

Which of the following pairs is mismatched?
A)

Malaria vector
B)

Salmonellosis vehicle transmission
C)

Syphilis direct contact
D)

Influenza droplet infection
E)

None of the above
...E
26)

All of the following can contribute to postoperative infections except
A)

Using syringes more than once.
B)

Normal microbiota on the operating room staff.
C)

Errors in aseptic technique.
D)

Antibiotic resistance.
E)

None of the above.
...E
Figure 14.2




28)

A cold transmitted by a facial tissue is an example of
A)

Direct contact
B)

Droplet transmission
C)

Fomite
D)

Vector
E)

Vehicle transmission
...C
29)

Influenza transmitted by an unprotected sneeze is an example of
A)

Direct contact.
B)

Droplet transmission.
C)

Fomite.
D)

Vector.
E)

Vehicle transmission.
...B
30)

A sexually transmitted disease is an example of
A)

Direct contact.
B)

Droplet transmission.
C)

Fomite.
D)

Vector.
E)

Vehicle transmission.
...A
31)

Gastroenteritis acquired from roast beef is an example of
A)

Direct contact.
B)

Droplet transmission.
C)

Fomite.
D)

Vector.
E)

Vehicle transmission.
...E
32)

A needlestick is an example of
A)

Direct contact.
B)

Droplet transmission.
C)

Fomite.
D)

Vector.
E)

Vehicle transmission.
...C
33)

Legionellosis transmitted by a grocery store mist machine is an example of
A)

Direct contact.
B)

Droplet transmission.
C)

Fomite.
D)

Vector.
E)

Vehicle transmission.
...E
34)

Plague transmitted by a flea is an example of
A)

Direct contact.
B)

Droplet transmission.
C)

Fomite.
D)

Vector.
E)

Vehicle transmission.
...D
35)

The most likely mode of transmission of pneumonic plague between humans is
A)

Direct contact.
B)

Droplet transmission.
C)

Fomite.
D)

Vector.
E)

Vehicle transmission.
...B
39)

Which one of the following is not an example of microbial antagonism?
A)

Acid production by bacteria
B)

Bacteriocin production
C)

Bacteria occupying host receptors
D)

Bacteria causing disease
E)

None of the above
...D
40)

The yeast Candida albicans does not normally cause disease because of
A)

Symbiotic bacteria.
B)

Antagonistic bacteria.
C)

Parasitic bacteria.
D)

Commensal bacteria.
E)

None of the above.
...B
41)

Haemophilus bacteria require heme protein produced by Staphylococcus bacteria. This is an example of
A)

Antagonism.
B)

Commensalism.
C)

Parasitism.
D)

Synergism.
E)

None of the above.
...B
42)

Which one of the following is not a zoonosis?
A)

Cat-scratch disease
B)

Hantavirus pulmonary syndrome
C)

Rabies
D)

Tapeworm
E)

None of the above
...
43)

Pseudomonas bacteria colonized the bile duct of a patient following his liver transplant surgery. This is an example of a
A)

Communicable disease.
B)

Latent infection.
C)

Nosocomial infection.
D)

Sporadic disease.
E)

None of the above.
...C
45)

Which one of the following does not contribute to the incidence of nosocomial infections?
A)

Formation of biofilms.
B)

Lapse in aseptic techniques.
C)

Gram-negative cell walls.
D)

Lack of hand-washing.
E)

Lack of insect control.
...C
Chemotherapy
The use of drugs to treat a disease
Antimicrobial drugs
Interfere with the growth of microbes within a host
Antibiotic
A substance produced by a microbe that, in small amounts, inhibits another microbe
Selective toxicity
A drug that kills harmful microbes without damaging the host
Bactericidal
Kill microbes directly
Bacteriostatic
Prevent microbes from growing
penicillin mode of action
inhibitors of cell wall synthesis
penicillim Ampicillin
Broad spectrum
penicillin Amoxicillin
broad spectrum,combined with inhibiyor of prnicillinase
Cephalosporin mode of action
inhibitors of cell wall synthesis
cephalosporin
First-generation: Narrow spectrum, gram-positive
Second-generation: Extended spectrum includes gram-negative
Third-generation: Includes pseudomonads; injected
Fourth-generation: Oral
bacitracin mode of action
inhibitors of cell wall synthesis
bacitracin
Topical application
Against gram-positives
Vamcomycin mode of action
inhibitor of cell wal synthesis
vamcomycin
Glycopeptide
Narrow spectrum
Important "last line" against antibiotic-resistant S. aureus (MRSA)
Antimycobacterial antibiotics
moed of action inhibitor of cell wall synthesis
Isoniazid (INH)
Inhibits mycolic acid synthesis
Ethambutol
Inhibits incorporation of mycolic acid
Chloramphenicol mode of action
inhibitors of protein synthesis
Broad spectrum
Binds 50S subunit; inhibits peptide bond formation
Disadvantage: Suppression of bone marrow activity
Aminoglycosides
Mode of action: inhibitors of protein synthesis
Streptomycin, neomycin, gentamycin
Useful against pseudomonads
Broad spectrum
Changes shape of 30S subunit
Disadvantage: Auditory nerve damage and damage to kidney.
Tetracyclines
Inhibitors of protein synthesis
Broad spectrum
Interferes with tRNA attachment
Works against intracellular parasites
Suppress normal intestinal microbiota and often cause superinfections.
Not advised for children and pregnant women
Macrolides
Inhibitors of protein synthesis
Ex Erythromycin(alternative to penicillin)
Only Gram-positives
Binds 50S; prevents translocation
Polymixin B
Injury to the plasma membrane
Prevents biosynthesis of fatty acids for the membrane
Ex: Polymyxin B
Topical
Combined with bacitracin and neomycin in over-the-counter preparation
gram negative bacteria including pseudomonas spp
Rifamycin
inhibitors of nucleic acid synthesis
Inhibits mRNA synthesis
Antituberculosis
Penetrate tissues and reach therapeutic levels Iin cerebrospinal fluids and abscesses.
Quinolones and fluoroquinolones
Inhibitors of nucleic acid synthesis
Nalidixic acid: Urinary infections
Ciprofloxacin
Inhibits DNA gyrase
Urinary tract infections
Sulfonamides (sulfa drugs)
Inhibit folic acid synthesis
Broad spectrum
Bacteriostatic
Antifungal drug
Polyenes
Amphotericin B
Inhibition of ergosterol synthesis
Antifungal drug
Azoles
Miconazole
Triazoles
Treatment of cuteneous mycoses, (athlet's foot, Yeast infection)
Antiviral drug
Nucleoside and nucleotide analogs
attachment uncoating
Antibiotic ressistance
A variety of mutations can lead to antibiotic resistance
Mechanisms of antibiotic resistance
Enzymatic destruction of drug
Prevention of penetration of drug
Alteration of drug's target site
Rapid ejection of the drug
Resistance genes are often on plasmids or transposons that can be transferred between bacteria
Misuse of antibiotics selects for resistance mutants. Misuse includes
Using outdated or weakened antibiotics
Using antibiotics for the common cold and other inappropriate conditions
Using antibiotics in animal feed
Failing complete the prescribed regimen
Using someone else's leftover prescription
Synergism
occurs when the effect of two drugs together is greater than the effect of either alone
Antagonism
occurs when the effect of two drugs together is less than the effect of either alone
1)

Penicillin was considered a "miracle drug" for all of the following reasons except
A)

It was the first antibiotic.
B)

It doesn't affect eukaryotic cells.
C)

It inhibits gram-positive cell wall synthesis.
D)

It has selective toxicity.
E)

None of the above.
...A
2)

The first antibiotic discovered was
A)

Quinine.
B)

Salvarsan.
C)

Streptomycin.
D)

Sulfa drugs.
E)

Penicillin.
...E
3)

Most of the available antimicrobial agents are effective against
A)

Viruses.
B)

Bacteria.
C)

Fungi.
D)

Protozoa.
E)

All of the above.
...B
4)

Antimicrobial peptides work by
A)

Inhibiting protein synthesis.
B)

Disrupting the plasma membrane.
C)

Complementary base-pairing with DNA.
D)

Inhibiting cell-wall synthesis.
E)

Hydrolyzing peptidoglycan.
...
5)

Semisynthetic penicillins differ from natural penicillins in all of the following respects except that both are
A)

Broad spectrum.
B)

Resistant to penicillinase.
C)

Resistant to stomach acids.
D)

Bactericidal.
E)

None of the above.
...D
6)

Which of the following antibiotics is not bactericidal?
A)

Aminoglycosides
B)

Cephalosporins
C)

Polyenes
D)

Rifampins
E)

Penicillin
...C
7)

Which one of the following does not belong with the others?
A)

Bacitracin
B)

Cephalosporin
C)

Monobactam
D)

Penicillin
E)

Streptomycin
...E
Figure 20.1



8)

The antibiotic tetracycline binds to the 30S subunit of the ribosome as shown in Figure 20.1. The effect is to
A)

Prevent attachment of tRNA.
B)

Prevent peptide bond formation.
C)

Prevent transcription.
D)

Stop the ribosome from moving along the mRNA.
E)

Prevent attachment of tRNA and mRNA.
...A
10)

Which of these antimicrobial agents has the fewest side effects?
A)

Streptomycin
B)

Tetracycline
C)

Penicillin
D)

Erythromycin
E)

Chloramphenicol
...C
11)

All of the following act by competitive inhibition except
A)

Ethambutol.
B)

Isoniazid.
C)

Streptomycin.
D)

Sulfonamide.
E)

None of the above.
...C
12)

Which of the following methods of action would be bacteriostatic?
A)

Competitive inhibition with folic acid synthesis
B)

Inhibition of RNA synthesis
C)

Injury to plasma membrane
D)

Inhibition of cell wall synthesis
E)

None of the above
...A
13)

Which of the following antibiotics is recommended for use against gram-negative bacteria?
A)

Polyenes
B)

Bacitracin
C)

Cephalosporin
D)

Penicillin
E)

Polymyxin
...E
14)

Which of the following antimicrobial agents is recommended for use against fungal infections?
A)

Amphotericin B
B)

Bacitracin
C)

Cephalosporin
D)

Penicillin
E)

Polymyxin
...A
17)

More than half of our antibiotics are
A)

Produced by fungi.
B)

Produced by bacteria.
C)

Synthesized in laboratories.
D)

Produced by Fleming.
E)

None of the above.
...B
Figure 20.3



18)

The antibiotic erythromycin binds to the 50S subunit of the ribosome as shown in Figure 20.3. The effect is to
A)

Prevent attachment of tRNA.
B)

Prevent peptide bond formation.
C)

Prevent transcription.
D)

Stop the ribosome from moving along the mRNA.
E)

None of the above.
...
Figure 20.4



19)

The antibiotic streptomycin binds to the 30S subunit of the ribosome as shown in Figure 20.4. The effect is to
A)

Cause misreading of mRNA in 70S ribosomes.
B)

Prevent binding of tRNA in eukaryotes.
C)

Prevent polypeptide elongation in eukaryotes.
D)

Prevent peptide bond formation in prokaryotes.
E)

None of the above.
...D
20)

Which compound would be the most useful to treat candidiasis?
A)

Uracil
B)

Thymine
C)

Flucytosine
D)

Guanine
E)

None of the above
...C
21)

Which of the following antibiotics are used to treat fungal infections?

1. Aminoglycosides
2. Cephalosporins
3. Griseofulvin
4. Polyenes
5. Bacitracin

A)

1, 2, and 3
B)

3 and 4
C)

3, 4, and 5
D)

4 and 5
E)

All of the antibiotics
...B
22)

All of the following antibiotics interfere with cell wall synthesis except
A)

Cephalosporins.
B)

Macrolides.
C)

Natural penicillins.
D)

Semisynthetic penicillins.
E)

Vancomycin.
...B
23)

The antimicrobial drugs with the broadest spectrum of activity are
A)

Aminoglycosides.
B)

Chloramphenicol.
C)

Lincomycin.
D)

Macrolides.
E)

Tetracyclines.
...E
24)

Which of the following statements is false?
A)

Fluoroquinolone inhibits DNA synthesis.
B)

Acyclovir inhibits DNA synthesis.
C)

Amantadine inhibits release of viral nucleic acid.
D)

Interferon inhibits glycolysis.
E)

None of the above.
...D
25)

Protozoan and helminthic diseases are difficult to treat because
A)

Their cells are structurally and functionally similar to human cells.
B)

They replicate inside human cells.
C)

They don't have ribosomes.
D)

They don't reproduce.
E)

None of the above.
...A
26)

Which of the following organisms would most likely be sensitive to natural penicillin?
A)

L forms
B)

Streptococcus pyogenes
C)

Penicillinase-producing Neisseria gonorrhoeae
D)

Penicillium
E)

Mycoplasma
...A
27)

All of the following statements about drug resistance are true except
A)

It may be carried on a plasmid.
B)

It may be transferred from one bacterium to another during conjugation.
C)

It may be due to enzymes that degrade some antibiotics.
D)

It is found only in gram-negative bacteria.
E)

It may be due to increased uptake of a drug.
...D
28)

All of the following are advantages of using two antibiotics together except
A)

Prevention of drug resistance.
B)

Lessening the toxicity of individual drugs.
C)

Two are always twice as effective as one.
D)

Providing treatment prior to diagnosis.
E)

None of the above.
...C
29)

Drug resistance occurs
A)

Because bacteria are normal microbiota.
B)

When antibiotics are used indiscriminately.
C)

Against antibiotics and not against synthetic chemotherapeutic agents.
D)

When antibiotics are taken after the symptoms disappear.
E)

All of the above.
...B
33)

Which of the following would be selective against the tubercle bacillus?
A)

Bacitracin inhibits peptidoglycan synthesis
B)

Ethambutol inhibits mycolic acid synthesis
C)

Streptogramin inhibits protein synthesis
D)

Streptomycin inhibits protein synthesis
E)

Vancomycin inhibits peptidoglycan synthesis
..
34)

In the presence of penicillin a cell dies because
A)

It lacks a cell wall.
B)

It plasmolyzes.
C)

It undergoes osmotic lysis.
D)

It lacks a cell membrane.
E)

None of the above.
...C
38)

Which of the following statements about drugs that competitively inhibit DNA polymerase or RNA polymerase is not true?
A)

They cause mutations.
B)

They are used against viral infections.
C)

They affect host cell DNA.
D)

They are too dangerous to be used.
E)

None of the above.
...A
40)

Which of the following is not bactericidal?
A)

Tetracycline
B)

Natural penicillin
C)

Streptomycin
D)

Bacitracin
E)

Semisynthetic penicillin
...
Which of these antimicrobial agents has the fewest side effects?
A) Streptomycin
B) Tetracycline
C) Penicillin
D) Erythromycin
E) Chloramphenicol
C
Which of the following does NOT constitute an advantage of using two antibiotics together?
A) It can prevent drug resistance.
B) It lessens the toxicity of individual drugs.
C) Two are always twice as effective as one.
D) It allows treatment to be provided prior to diagnosis.
E) All of these are advantages.
C
Which of the following antimicrobial agents is recommended for use against fungal infections?
A) Amphotericin B
B) Bacitracin
C) Cephalosporin
D) Penicillin
E) Polymyxin
A
Which of the following statements about drug resistance is false?
A) It may be carried on a plasmid.
B) It may be transferred from one bacterium to another during conjugation.
C) It may be due to enzymes that degrade some antibiotics.
D) It is found only in gram-negative bacteria.
E) It may be due to increased uptake of a drug
D
The antibiotic tetracycline binds to the 30S subunit of the ribosome as shown in Figure 20.1. The effect is to
A) Prevent attachment of tRNA.
B) Prevent peptide bond formation.
C) Prevent transcription.
D) Stop the ribosome from moving along the mRNA.
E) Prevent attachment of tRNA and mRNA.
A
6. Which of the following antibiotics is recommended for use against gram-negative bacteria?
A) Polyenes
B) Bacitracin
C) Cephalosporin
D) Penicillin
E) Polymyxin
E
Which of the following antibiotics does NOT interfere with cell wall synthesis?
A) Cephalosporins
B) Macrolides
C) Natural penicillins
D) Semisynthetic penicillins
E) Vancomycin
B
Penicillin was considered a "miracle drug" for all of the following reasons EXCEPT
A) It was the first antibiotic.
B) It doesn't affect eukaryotic cells.
C) It inhibits gram-positive cell wall synthesis.
D) It has selective toxicity.
E) It kills bacteria.
A
Drug resistance occurs
A) Because bacteria are normal microbiota.
B) When antibiotics are used indiscriminately.
C) Against antibiotics and not against synthetic chemotherapeutic agents.
D) When antibiotics are taken after the symptoms disappear.
E) All of these
B
Which of the following antibiotics is NOT bactericidal?
A) Aminoglycosides
B) Cephalosporins
C) Polyenes
D) Rifampins
E) Penicillin
C
Which one of the following does NOT belong with the others?
A) Bacitracin
B) Cephalosporin
C) Monobactam
D) Penicillin
E) Streptomycin
E
13. Which of the following methods of action would be bacteriostatic?
A) Competitive inhibition with folic acid synthesis
B) Inhibition of RNA synthesis
C) Injury to plasma membrane
D) Inhibition of cell wall synthesis
E) Competitive inhibition with DNA gyrase
A
12.



In Table 20.2, the antibiotic that exhibited bactericidal action was
A) A.
B) B.
C) C.
D) D.
E) Can't tell.
E
14. Most of the available antimicrobial agents are effective against
A) Viruses.
B) Bacteria.
C) Fungi.
D) Protozoa.
E) All of these.
B
The antimicrobial drugs with the broadest spectrum of activity are
A) Aminoglycosides.
B) Chloramphenicol.
C) Lincomycin.
D) Macrolides.
E) Tetracyclines.
E
Pathogenicity
The ability to cause disease
Virulence
The extent of pathogenicity
PORTAL OF ENTRY
Mucous membranes
respiratory tract
gastrointetinal tract genitourinary tract
conjunctiva
Skin
Parenteral route
* many pathogens have their preffered portal of entry to be able to cause disease
ID50
Infectious dose for 50% of the test population
LD50
Lethal dose (of a toxin) for 50% of the test population
adherence
Adhesins/ligands bind to receptors on host cells
Glycocalyx: Streptococcus mutans
Fimbriae: Escherichia coli
M protein: Streptococcus pyogenes
Form biofilms
microbial mechanism of pathogenicity
1. capsules
Prevent phagocytosis
Streptococcus pneumoniae
Haemophilus influenzae
Bacillus anthracis
2. call wall components
M protein resists phagocytosis
Streptococcus pyogenes
Opa protein inhibits T helper cells
Neisseria gonorrhoeae
Mycolic acid (waxy lipid) resists digestion
Mycobacterium tuberculosis
3. enzymes
Enzymes secreted by the pathogen
Dissolve structural chemicals in the body
Help pathogen maintain infection, invade further, and avoid body defenses
4. Antigenic variation ex flu gonorrea
Antigens are surface protein that induce immune response by the host.
Alter surface proteins to evade immune response
5.Invasion
Invasins
Salmonella alters host actin to enter a host cell
Use actin to move from one cell to the next
Listeria
how pathogens damge host cell
1. using the host nutrients siderphores
Siderophores releases by the pathogen takes away and use host's iron.
2. Direct damage
Disrupt host cell function
Produce waste products
Toxins
Toxin
Substance that contributes to pathogenicity
Toxigenicity
Ability to produce a toxin
Toxemia
Presence of toxin in the host's blood
Toxoid
Inactivated toxin used in a vaccine
Antitoxin
Antibodies against a specific toxin
Exotosins
mostly gram positive
by products of growing cell
protein
no fever
neutralized by antitoxin
LD50 small
Based on structure and function there are three types of exotoxins
1. A-B toxins
2. Membrane disrupting toxins
3. superantigens
A-B toxins
Consists of two parts designated A and B
Part A is the active(enzyme) component and B is the binding component.
Ex: Diphtheria toxin
Membrane-Disrupting Toxins
Lyse host's cells by
Making protein channels in the plasma membrane
Leukocidins
Hemolysins
Streptolysins
Disrupting phospholipid bilayer
Superantigens
Cause an intense immune response due to release of cytokines from host cells
Symptoms: fever, nausea, vomiting, diarrhea, shock, and death
Endotoxins
gram negative
outer membrane
Lipid a
fever
its not neutralized by antitoxin
ld50 latge
Part of the outer portion of the cell wall of gram negatives
Lipid A is the endotoxin.
Cause chills, fever, weakness, generalized aches, shock.
Shock: Life threatening decrease in blood pressure.
Dissimilated intravascular coagulation(DIC)
Fever(pyrogenic response)
phatogenic properties of viruses
Attachment sites mimic substances useful to cells.
Hiding attachment sites from immune response
Attacking immune system directly
Cytopathic Effects of Viruses Visible effects of viral infection
Portal of exit
port of entry is the same as portalof exit
Respiratory tract
Coughing and sneezing
Gastrointestinal tract
Feces and saliva
Genitourinary tract
Urine and vaginal secretions
Skin
Blood
Biting arthropods and needles or syringes
Cytopathic effects are changes in host cells due to
A) Viral infections.
B) Protozoan infections.
C) Fungal infections.
D) Bacterial infections.
E) Helminthic infections.
A
How do A-B toxins function?
A) The A domain binds to a target cell receptor, while the B domain has a specific function.
B) The B domain binds to a target cell receptor, while the A domain has a specific function.
Feedback:
Correct!

C) The B domain acts as a neurotoxin, while the A domain acts as a cytotoxin.
D) They bind to the membrane of the host cell, creating a pore.
B
3. Which is a method of avoiding phagocytosis?
A) Producing fimbriae
B) Inducing endocytosis
C) Producing toxins
D) Inducing TNF
E) Producing iron-binding proteins
B
4. Endotoxins are
A) Associated with gram-positive bacteria.
B) Specific in their method of action.
C) Part of the gram-negative cell wall.
D) Excreted from the cell.
E) A-B toxins
C
Which of the following CANNOT be used for adherence?
A) Fimbriae
B) Cell membrane mannose
C) Glycoproteins
D) Lipoproteins
E) Capsules
B
The ID50 is a
A) Measure of pathogenicity.
B) Dose that will cause an infection in 50% of the test population.
C) Dose that will kill some of the test population.
D) Dose that will cause an infection in some of the test population.
E) Dose that will kill 50% of the test population.
B
The most frequently used portal of entry for pathogens is the
A) Mucous membranes of the respiratory tract.
B) Mucous membranes of the gastrointestinal tract.
C) Skin.
D) Parenteral route.
E) All are used equally
A
8. Most pathogens that gain access through the skin
A) Can penetrate intact skin.
B) Just infect the skin itself.
C) Enter through hair follicles and sweat ducts.
D) Must adhere first while their invasive factors allow them to penetrate.
E) Must be injected.
C
Which of the following does NOT contribute to the virulence of a pathogen?
A) Numbers of microorganisms that gain access to a host
B) Cell wall
C) Toxins
D) Enzymes
E) All of these contribute to a pathogen's virulence.
E
10. A needlestick is an example of which portal of entry?
A) Skin
B) Parenteral route
C) Mucous membranes
D) All of these
E) None of these
B
What cell structure does Neisseria gonorrhoeae use to attach and enter host epithelial cells?
A) fimbriae
Feedback:
Correct!

B) cell wall waxes
C) M proteins
D) capsules
E) flagella
A
Which of the following statements about M protein is false?
A) It is found on Streptococcus pyogenes.
B) It is found on fimbriae.
C) It is heat- and acid-resistant.
D) It is readily digested by phagocytes.
E) It is a protein.
D
A cell wall can increase a bacterium's virulence because cell wall lipid A
A) Resists phagocytosis.
B) Helps the bacterium attach.
C) Destroys host tissues.
D) Is toxic.
E) All bacteria have a cell wall and all are not pathogenic; therefore, cell walls do not contribute to virulence
D
Which of the following is NOT considered entry via the parenteral route?
A) Injection
B) Bite
C) Surgery
D) Hair follicle
E) Skin cu
D
15. Which of the following statements about exotoxins is generally false?
A) They are more potent than endotoxins.
B) They are composed of proteins.
C) They are not destroyed by heat.
D) They have specific methods of action.
E) They are produced by gram-positive bacteria.
C
Susceptibility
Lack of resistance to a disease
Immunity
Ability to ward off disease
Innate immunity
Defenses against any pathogen
Adaptive immunity
Immunity, resistance to a specific pathogen
hUMAN receptor
Host Toll-like receptors (TLRs) attach to
TLRs induce cytokines that regulate the intensity and duration of immune responses
Pathogen receptor
Pathogen-associated molecular patterns (PAMPs)
First line of defense
intact skin
mucous membrane and their secretion
Normal microbiota
Second line of defense
Phagocytes such as neutrophils,eosinophils,dentritic cell and macrophages
inflammation
fever
antimicrobial subtances
Physical factor of first line of defense
1.
Skin
Epidermis consists of tightly packed cells with
Keratin, a protective protein
2. Mucous membranes
Mucus: Traps microbes
Ciliary escalator: Microbes trapped in mucus are transported away from the lungs
3. Lacrimal apparatus: Washes eye
Saliva: Washes microbes off
Urine: Flows out
Vaginal secretions: Flow out
Microbial antagonism/competitive exclusion
Normal microbiota compete with pathogens or alter the environment
Various activities of the normal microbiota make it hard for pathogens to compete
Consumption of nutrients makes them unavailable to pathogens
Create an environment unfavorable to other microorganisms by changing pH
Helps stimulate the body's second line of defense
Promote overall health by providing vitamins to host
May be opportunistic pathogens
The differential white blood cell count test can signal signs of disease
Increased eosinophils can indicate allergies or parasitic worm infection
Bacterial diseases often show increase in leukocytes and in neutrophils
Viral infections show increase in lymphocytes
Second line of defense
Acute-phase proteins activated (complement, cytokine, and kinins)
Vasodilation (histamine, kinins, prostaglandins, and leukotrienes)
Redness
Swelling (edema)
Pain
Heat
the process of inflammation
Nonspecific response to tissue damage resulting from various causes
Characterized by redness, heat, swelling, and pain
Two types
Acute
Chronic
Acute inflammation
Develops quickly and is short lived
Is usually beneficial
Important in the second line of defense
Dilation and increased permeability of the blood vessels
Migration of phagocytes
Tissue repair
Chronic inflammation
Develops slowly and lasts a long time
Can cause damage to tissues
Fever
Abnormally high body temperature
Hypothalamus normally set at 37°C
Gram-negative endotoxin cause phagocytes to release interleukin-1 (IL-1)
Hypothalamus releases prostaglandins that reset the hypothalamus to a high temperature
Body increases rate of metabolism and shivering which raise temperature
Vasodilation and sweating: Body temperature falls (crisis)
chill is a sign of body temp rising
fever Advantages
Increases transferrins
Increases IL-1 activity
Produces Interferon
fever Disadvantages
Tachycardia
Acidosis
Dehydration
44-46°C fatal
Antimicrobial subtances the complement system
Set of serum proteins designated numerically according to the order of their discovery
Serum proteins activated in a cascade
Complement activation may occur in three pathways

Activated by
Antigen-antibody reaction (Classical pathway)
Proteins C3, B, D, P and a pathogen (Alternate pathway)
Activated by lectins, produced by liver(Lectin pathway)
Effects of Complement Activation
Opsonization or immune adherence: Enhanced phagocytosis
Membrane attack complex: Cytolysis
Attract phagocytes
Inflammation
ways of bacteria evading the complement system
Capsules prevent C activation
Surface lipid-carbohydrates prevent membrane attack complex (MAC) formation
Enzymatic digestion of C5a
others anticrobial substances
Transferrins
Bind serum iron
Antimicrobial peptides
Lyse bacterial cells
Barriers and assosiated chemicals mode of action
skin and mucous membranes prevent the entrance of pathogens, chemicals(eg sweat acid, lysozyme,mucus) enhance the protection
phagocytes mode of action
macrophages,neutrophils, and eosinophils ingest and destroy pathogens
extracellular killing mode of action
eosinophils and Nk lymphocytes kill pathogens without phagocytizing them
Complement system mode of action
components attract phagocytes, stimulates inflammation, and attack a pathogen's cytoplasmic membrane
Interferon mode of action
increase resistance of cells to viral infection, slow the spread of disease
defensins mode of action; interfere with membranes, internal signaling,metabolism and heat shock protein.
...
inflammation mode of action
increases the blood flow, capillary permeability, and migration of leukocytes into infected area, walls off infected region, increases local temperature
fever mode of action
mobilizes defenses,accelerates repairs,inhibits pathogens
Pasteur
observed immunity in chickens injected with weakened pathogens
Von Behring
received the Nobel Prize for development of antitoxin
Ehrlich's work
led to the identification of antibodies in serum
T and B cells develop from
stem cells in red bone marrow
Humoral immunity
B cells mature in the bone marrow
Chickens: Bursa of Fabricius
Due to antibodies
Cellular immunity
Due to T cells
T cells mature in the thymus
Antigen (Ag)
A substance that causes the body to produce specific antibodies or sensitized T cells
Antibodies (Ab) interact with epitopes or antigenic determinants
A substance with low molecular weight is not antigenic unless it is attached to a carrier molecule.
Low molecular weight antigens are called haptens
.
Hapten
Antigen is combined with carrier molecules
Globular proteins called
immunoglobulins
The number of antigen-binding sites determines
valence
Each antibody has at least two binding sites (bivalent)
There are five classes of immunoglobulins
IgG, IgM, IgA, IgD and Ig E
IgG
Monomer
80% of serum Abs
Fix complement
In blood, lymph, and intestine
Cross placenta
Enhance phagocytosis; neutralize toxins and viruses; protects fetus and newborn
Half-life = 23 days
IgM
Pentamer
5-10% of serum Abs
Fix complement
In blood, in lymph, and on B cells
Agglutinates microbes; first Ab produced in response to infection
Half-life = 5 days
IgA
Dimer
10-15% of serum Abs
In secretions
Mucosal protection
Half-life = 6 days
IgD
Monomer
0.2% of serum Abs
In blood, in lymph, and on B cells
On B cells, initiate immune response
Half-life = 3 days
IgE
Monomer
0.002% of serum Abs
On mast cells, on basophils, and in blood
Allergic reactions; lysis of parasitic worms
Half-life = 2 days
Major histocompatibility complex (MHC)
collection of genes encoding glycoproteins expressed on plasma membrane of mammalian cells
T-dependent antigens
Antigen that requires a TH cell for antibody production
TH cell produces cytokines that activate the B cell
Antibody producing B cells are called plasma cells
Longlived activated B cells responsible for enhanced secondary response is called memory cells
T-independent antigens
Stimulate the B cell to make Abs
antibody Fuction
Function in several ways
Activation of complement: part of second line of defense
Stimulation of inflammation: part of second line of defense
Neutralization: neutralize toxin by binding to a critical portion of toxin.
Opsonization: stimulate phagocytosis by binding to neutrophils and macrophages.
Agglutination: Bind to two microbial cells causing aggregation and thus increasing the chance of detection.
Killing by Oxidation: Catalyze the production of hydrogen peroxide and other potent oxidants to kill bacteria.
Agglutination
reduces number of infectios units to be dealt with
Opsonization
coating antigen with antibody enhances phagocytosis
Complement fixation
causes inflammation, opsonization and cell lysis(cytolisis)
neutralization; blocks ahesion of bacteria or attachement of toxin and viruses to mucosa
...
T Cells and Cellular Immunity
Produced in the red bone marrow and mature under the influence of the thymus
Circulate in the lymph and blood and migrate to the lymph nodes, spleen, and Peyer's patches
Part of the cell-mediated immune response because they act directly against various antigens
Endogenous invaders
Many of the body's cells that harbor intracellular pathogens
Abnormal body cells such as cancer cells that produce abnormal cell surface proteins
Classes of T cells
T helper cells (TH)
T cytotoxic cells (TC)
T Helper Cells
CD4+ or TH cells
TCRs recognize Ags and MHC II on APC
TLRs are a costimulatory signal on APC and TH
TH cells produce cytokines and differentiate into
TH1
TH2
Memory cells
TH1 produces IFN-gwhich activates cells related to cell-mediated immunity, macrophages, and Abs
TH2 activate eosinophils and B cells to produce IgE
T Cytotoxic Cells
CD8+ or TC cells
Target cells are self carrying endogenous antigens
Activated into cytotoxic T lymphocytes (CTLs)
CTLs recognize Ag + MHC I
Induce apoptosis in target cell
CTL releases perforin and granzymes
Natural Killer (NK) Cells
Granular leukocytes destroy cells that don't express MHC I
Kill virus-infected and tumor cells
Attack parasites
Antibody titer
is the amount of Ab in serum
Primary response occur
s after initial contact with antigen
Secondary (memory or anamnestic) response occurs
after second exposure
Naturally acquired active immunity
Resulting from infection
Naturally acquired passive immunity
Transplacental or via colostrum
Artificially acquired active immunity
Injection of Ag (vaccination)
Artificially acquired passive immunity
Injection of Ab
Serology
The study of reactions between antibodies and antigens
Antiserum
The generic term for serum because it contains Ab
Globulins
Serum proteins
Immunoglobulins
Antibodies
Gamma (y) globulin
Serum fraction containing Ab
Transient flora differ from normal flora because transient flora

a. Cause diseases.

b. Are found in certain location on the host.

c. Are acquired by direct contact.

d. Are present for a relatively short time.

e. None of the above.
d
Which of the following diseases is not spread by droplet infection?

a. Botulism

b. Tuberculosis

c. Measles

d. Common Cold

e. Diphtheria
a
Which of the following is a fomite?

a. Water.

b. Droplets from a sneeze.

c. Pus.

d. Insects.

e. A hypodermic needle.
E
Which of the following statements is true?

a. Symbiosis refers to different organisms living together.

b. Members of a symbiotic relationship cannot live without each other.

c. A parasite is not in a symbiosis with its host.

d. Symbiosis refers to different organisms living together and benefiting from each other.

e. At least one member must benefit in a symbiotic relationship.
A
Which of the following is mismatched?

a. Acute ‑ a short lasting primary infection

b. Inapparent ‑ infection characteristic of a carrier state

c. Chronic ‑ a disease that develops slowly and lasts for months.

d. Primary infection ‑ an initial illness.

e. Secondary infection ‑ a long ‑ lasting illness.
E
Which of the following pairs is mismatched?

a. Etiology ‑ cause of disease.

b. Pathogenic ‑ capable of causing disease.

c. Infection ‑ disease.

d. Symptoms ‑ changes in body function.

e. Virulence ‑ degree of pathogenicity.
C
7.Which of the following is not a predisposing factor to disease?

a. Inadequate nutrition.

b. Fatigue.

c. Age.

d. Preexisting illness.

e. All are predisposing factors.
E
8. Which of the following is mismatched?

a. Endemic ‑ a disease that is constantly present in a population.

b. Epidemic ‑ fraction of the population having a disease at a specific time.

c. Pandemic ‑ a disease that affects a large number of people in the world in a short time.

d. Sporadic ‑ a disease that affects a population occasionally.

e. Pathogen ‑ disease causing.
B
9. Which of the following is NOT a communicable disease?

a. Rabies

b. Common cold

c. Measles

d. Tetanus

e. Plague
D
10. Which of the following is mismatched?

a. Malaria ‑ Vector

b. Salmonellosis ‑ common vehicle

c. Syphilis ‑ direct contact

d. Influenza ‑ droplet infection

e. All are correctly matched.
E
11. Which of the following does not contribute to a pathogen's invasiveness?

a. Toxins

b. Capsule

c. Cell wall proteins

d. Hyaluronidase

e. Leukocidins
A
12. Which of the following is mismatched?

a. Leukocidins ‑ destroy neutrophils.

b. hemolysins ‑ lyse red blood cells.

c. Hyaluronidase ‑ break down substance between cells.

d. Kinase ‑ destroys fibrin clots.

e. Coagulase ‑ destroys fibrin clots.
E
. Which of the following is generally not true about exotoxins

a. they are more potent than endotoxins.

b. they are composed of proteins.

c. they are not destroyed by heat

d. they have specific methods of action.

e. they are produced by gram‑positive bacteria.
C
14. Symptoms of protozoan and helminthic diseases are due to

a. Tissue damage due to growth of the parasite on the tissues.

b. Waste products excreted by the parasite.

c. Products released from damaged tissues.

d. All of the above.

e. None of the above.
D
15. Which of the following is not a mechanical factor to protect the skin and mucous membranes from infection?

a. Layers of cells

b. Tears

c. Saliva

d. Lysozyme

e. All are mechanical factors.
D
16. Which of the following is not a characteristic of inflammation?

a. Redness

b. Pain

c. Local heat.

d. Fever

e. Swelling
D
17. The best definition of an antigen is

a. Something foreign in the body.

b. A macromolecule that elicits an antibody response and can combine with these antibodies.

c. A chemical that combines with antibodies.

d. A pathogen.

e. A protein that combines with antibodies.
B
18. The chemicals causing symptoms of anaphylaxis are

a. Found in basophils and mast cells

b. Interferons

c. Antigens

d. Antigen‑antibody complexes

e. The proteins of the complement system.
A
19. Which of the following is an example of systemic anaphylaxis?

a. Hay fever

b. Asthma

c. Shock

d. Hives

e. All of the above.
C
20. Autoimmunity may be due to

a. Recognition of "foreign" antigens.

b. Cross reactive IgG and IgM antibodies.

c. Immunologic paralysis

d. Immunologic suppression

e. Immunologic tolerance
B
21. Which type of graft is the least compatible?

a. Autograft d. Xenograft

b. Allograft e. All are equally compatible.

c. Isograft
D
a. Native immunity

b. Naturally acquired active immunity

c. Naturally acquired passive immunity

d. Artificially acquired active immunity

e. Artificially acquired passive immunity



22. Type of immunity resulting from vaccination.
Artificially acquired active immunity
23. Type of immunity resulting from transfer of antibodies from one individual to a susceptible individual by means of injection.
Artificially acquired passive immunity
24. Immunity resulting from recovery from an infection.
Naturally acquired active immunity
25. A human's resistance to canine distemper.
Native immunity
26. Newborn's immunity due to the transfer of antibodies across the placenta.
Naturally acquired passive immunity
Match the following choices to the statements in questions 27‑31. Choices may be used once, more than once, or not at all.



a. IgG

b. IgM

c. IgA

d. IgD

e. IgE

27. Antibodies found in mucus, saliva, and tears.
IgA
28. Antibodies that protect the fetus and newborn.
IgG
29. Antibodies that are found on mast cells and involved in allergic reactions
IgE
30. The first antibodies synthesized, a very large molecule.
IgM
31. Most abundant class of antibodies in serum.
IgG
Match the following choices to the questions 32‑35. Choices may be used once, more than once, or not at all.



a. Agglutination reaction

b. Complement fixation

c. ELISA (EIA)

d. Immunofluorescence

e. Precipitation reaction



32. Reaction between an antibody and soluble antigen, forming lattices.
Precipitation reaction
33. Reaction between antibody and particulate antigen.
Agglutination reaction
34. An indirect version using anti‑human globulin may be used to detect patient's antibodies against T. pallidum.
Immunofluorescence
35. Reaction using red blood cells as the indicator and hemolysis indicates an antigen‑antibody reaction.
Complement fixation
Use for questions 36‑39. Use once, more than once, or not at all.

a. desensitization

b. neutralization

c. opsonization

d. complementarity

e. resistance



36. The coating of a microorganism with plasma proteins such as complement and antibodies; enhances phagocytosis.
opsonization
37. Your body's ability to ward off disease.
resistance
38. Injecting small, repeated doses of the allergen (antigen) into the skin in order to produce blocking antibodies.
A
39. Antibodies blocking the cytopathic effect of viruses in cell cultures; can be used to identify viruses.
neutralization
40. An encapsulated bacterium can be virulent because the capsule

a. Resists phagocytosis

b. Helps the bacterium attach

c. Destroys host tissue

d. Interferes with physiological properties

e. Many pathogens don't have capsules, therefore, capsules do not contribute to virulence.
A
41. Which of the following exhibits the highest phagocytic activity?

a. basophils

b. neutrophils

c. lymphocytes

d. mast cells

e. eosinophils
B
42. Serology

a. is a powerful tool for diagnosing infectious diseases.

b. is the science of vaccine production.

c. uses the presence of specific antibody in serum to indicate exposure to pathogenic microbes.

d. can be used to identify bacteria isolated from patients with infectious diseases.

e. all except b
E
43. Which of the following diseases is NOT associated with endotoxins?

a. typhoid fever d. urinary tract infections

b. diphtheria e. all involve endotoxins.

c. epidemic Meningitis
B
45. Which of the following is NOT a reservoir of infection?

a. a sick person

b. a healthy person

c. a sick animal

d. a hospital

e. All are reservoirs.
E
46. The LD50 is a

a. measure of pathogenicity

b. Dose that will cause an infection in 50% of the test population.

c. Dose that will kill some of the test population.

d. Dose that will cause an infection in some of the test population.

e. Dose that will kill 50% of the test population.
E
47. The science that deals with when diseases occur and how they are transmitted is called

a. ecology

b. epidemiology

c. serology

d. morbidity and mortality

4. public health
B
48. Interferon is a substance

a. produced by a cell to protect itself from viral infection

b. produced by a virally‑infected cell which initiates the synthesis of molecules that inhibit viral replication in neighboring uninfected cells.

c. produced by a virally‑infected cell that prevents penetration of viruses into neighboring infected cells.

d. that interferes with the reproduction of bacteria.

e. that interferes with the lysis of virally‑infected cells.
B
49. Which of the following is mismatched?

a. Complement ‑ a group of proteins found in normal which act in a cascade to lyse cells.

b. Toxoid ‑ an endotoxin used as a vaccine

c. Antibody ‑ a protein produced by the body in response to an antigen and capable of combining specifically with that antigen.

d. Haptene ‑ an incomplete antigen; needs a carrier molecule

e. Antitoxin ‑ antibodies against a toxin
B
50. Cancer cells may escape the immune system because

a. They are recognized as "self".

b. Antibodies are not formed against cancer cells

c. Cytotoxic T cells react with tumor specific antigens

d. Tumor cells shed their specific antigens

e. None of the above.
D
1. Which of the following results in long-term immunity?
a. the passage of maternal antibodies to her developing fetus
b. the inflammatory response to a splinter
c. the administration of serum obtained from people immune to rabies
d. the administration of the chicken pox vaccine
e. the passage of maternal antibodies to her nursing infant
D
2. Which of the following best describes the difference in the way B cells and cytotoxic T cells respond to invaders?
a. B cells kills viruses directly; cytotoxic T cells kills virus-infected cells.
b. B cells secrete antibodies against a virus; cytotoxic T cells kill virus-infected cells.
c. B cells accomplish cell-mediated immunity; cytotoxic T cells accomplish humoral immunity.
d. B cells respond the first time the invader is present; cytotoxic T cells respond subsequent times.
B
3. Inflammation
a. aids in temporary repair at an injury site
b. slows the spread of pathogens
c. facilitates permanent repair
d. All of the above
e. None of the above
D
4. Compared with nonspecific defenses, specific defenses
a. do not distinguish between one threat and another
b. are always present at birth
c. protect against threats on an individual basis
d. deny entrance of pathogens to the body
C
5. Which of the following is not part of the body's nonspecific defense system?
a. inflammation
b. phagocytosis by neutrophils
c. phagocytosis by macrophages
d. antibodies
D
6. The process by which neutrophils squeeze through capillary walls in response to inflammatory signals is called
a. emigration
b. chemotaxis
c. margination
d. opsonization
A DIAPADESIS
7. Which antibody class can fix complement?
a. IgA
b. IgD
c. IgE
d. IgF
e. IgM
E
8. Which antibody class is abundant in body secretions?
a. IgA
b. IgD
c. IgE
d. IgG
e. IgM
A
9. Septic shock due to gram-positive bacteria is caused by
a. A-B toxins.
b. Lipid A.
c. membrane-disrupting toxins.
d. superantigens.
D
10. Injectable drugs are tested for endotoxins by:
a. The Limulus amoebocyte lysate test.
b. counting the viable bacteria.
c. filtering out the cells.
d. looking for turbidity.
e. None of the above.
A
11. Which of the following choices show the order in which white blood cells migrate to infected tissues?
a. Macrophages - monocytes
b. Lymphocytes - macrophages
c. Neutrophils - macrophages
d. Neutrophils - monocytes
e. Macrophages - neutrophils
D
For questions 12-15, match the letters to the appropriate description.

A. Neutrophil
B. B cell
C. Mast cell
D. Helper T cell
E. Memory B cell

12. Carries out humoral immunity
B CELL
13. Cell most commonly infected by HIV
HELPER T CELL
14. Contains histamines that trigger allergy symptoms
MAST CELL
15. A phagocytic white blood cell
NEUTROPHIL
16. Cytopathic effects are changes in the host cells due to
a. viral infections.
b. protozoan and helminthic infections.
c. fungal infections.
d. bacterial infections.
e. All of the above.
A
17. A needlestick is an example of which portal of entry?
a. Skin
b. Parenteral route
c. Mucous membranes
d. Gastrointestinal
B
18. The mechanism by which gram-negative bacteria can cross the blood-brain barrier.
a. Producing fimbriae
b. Inducing endocytosis
c. Producing toxins
d. Inducing TNF
e. All of the above
D
19. Which of the following does not cause vasodilation?
a. Kinins
b. Prostaglandins
c. Lysozymes
d. Histamine
C
20. Which of the following is involved in resistance to parasitic helminths?
a. Basophil
b. Eosinophil
c. Lymphocyte
d. Monocyte
e. Neutrophil
B
21. Type of immunity resulting from the transfer of antibodies from one individual to a susceptible individual by means of injection.
a. Innate immunity
b. Naturally acquired active immunity
c. Naturally acquired passive immunity
d. Artificially acquired active immunity
e. Artificially acquired passive immunity
E
22. The best definition of an antibody is
a. a serum protein.
b. a protein that inactivates or kills an antigen.
c. a protein made in response to an antigen that can combine with that antigen.
d. an enzyme.
e. None of the above
...C
23. Which of the following causes pores in target cells?
a. Antigen
b. Hapten
c. IL-1
d. IL-2
e. Perforin
...E
24. Cell death caused by perforin is caused by
a. CD8 cells
b. TH cells
c. B cells
d. TC cells
D
25. Which subunit of the exotoxin is the binding portion of the molecule?
a. A
b. B
c. C
d. D
e. E
B
26. Type of immunity resulting from vaccination.
a. Innate immunity
b. Naturally acquired active immunity
c. Naturally acquired passive immunity
d. Artificially acquired active immunity
e. Artificially acquired passive immunity
D
27. The specificity of an antibody is due to
a. the heavy chains
b. the light chains
c. the constant regions of the heavy and light chains
d. the variable regions of the heavy and light chains
e. All of the above
D
28. In the figure, the arrow at time d indicates
a. the time of exposure to the same antigen at time a.
b. the secondary response.
c. the primary response.
d. exposure to a new antigen.
D
29. IL-2, produced by TH cells,
a. activate macrophages.
b. stimulates TH cell maturation.
c. causes phagocytosis.
d. activates antigen-presenting cells.
B
30. Most Gram-negative bacteria have a lipopolysaccharide (LPS) which is found in the
a. plasma membrane.
b. cell wall.
c. inner membrane.
d. outer membrane.
e. periplasmic space.
D
31. The definition of lysogeny is
a. phage DNA is incorporated into the host cell DNA.
b. lysis of the host cell due to a phage.
c. the period during replication when virions are not present.
d. when the burst time takes an unusually long time.
A
32. Which of the following is not a membrane-disrupting toxin?
a. A-B toxin
b. Hemolysin
c. Leukocidins
d. Streptolysin O
e. Streptolysin S
A
Use this figure to answer questions 33-34.



33. Which areas are different for all IgM antibodies?
a. a and b
b. a and c
c. b and c
d. c and d
e. a and d
A
34. What can attach to a host cell?
a. a and c
b. b and c
c. b
d. d
e. e
C
35. Cytotoxins having a specific toxic action upon cells/tissues of the liver are
a. hepatotoxins.
b. cardiotoxins.
c. enterotoxins.
d. neurotoxins.
e. nephrotoxins.
...A
36. The best definition of cell mediated immunity is:
a. immunity involving macrophages.
b. immunity involving stem cells.
c. immunity involving the lymphatic system.
d. immunity involving T cells.
e. immunity involving platelets.
...D
37. The process by which microorganisms attach themselves to cells is
a. infection.
b. contamination.
c. disease.
d. adhesion.
...D
38. The nature of bacterial capsules
a. causes widespread blood clotting.
b. allows phagocytes to readily engulf these bacteria.
c. affects the virulence of these bacteria.
d. has no effect on the virulence of bacteria.
e. All of the above
...C
39. Which of the following is not an effect of complement activation?
a. Interference with viral replication
b. Bacterial cell lysis
c. Opsonization
d. Increased phagocytic activity
e. Increased blood vessel permeability/
...A
1. Wandering macrophages experience margination.
...TRUE
2. Lymphocytes are large agranulocytes.
...FALSE
3. The hypothalamus of the brain controls body temperature.
...TRUE
4. Apoptosis is the term used to describe cellular suicide.
...TRUE
5. Interferon is produced by viruses.
...FALSE
6. Exotoxins are composed of proteins.
...TRUE
7. Histamine increases permeability of capillaries so that leukocytes can more readily reach the infection site.
...TRUE
8. C3a causes opsonization.
...FALSE
9. Like B cells, T cells originate from stem cells in bone marrow.
...TRUE
10. In a process called clonal deletion, lymphocytes that destroy host tissues are destroyed.
...TRUE
1. The major significance of Koch's work was that
a. microorganisms are present in a diseased animal.
b. diseases can be transmitted from one animal to another.
c. microorganisms can be cultured.
d. microorganisms cause disease.
e. microorganisms are the result of disease.
...D
2. Which of the following definitions is incorrect?
a. Endemic - a disease that is constantly present in a population
b. Epidemic - fraction of the population having a disease at a specified time
c. Pandemic - a disease that affects a large number of people in the world in a short time
d. Sporadic - a disease that affects a population occasionally
e. Herd immunity - immunity in most of the population
...B
3. Which type of infection can be caused by septicemia?
a. Bacteremia
b. Focal infection
c. Local infection
d. Septicemia
e. Systemic infection
...E
4. Which of the following is a fomite?
a. Water
b. Droplets from a sneeze
c. Pus
d. Insects
e. A hypodermic needle
...E
5. The science that deals with when diseases occur and how they are transmitted is called
a. ecology.
b. epidemiology.
c. communicable disease.
d. morbidity and mortality.
e. public health.
...B
6. Emergence of infectious diseases can be due to all of the following except
a. antibiotic resistance.
b. climatic changes.
c. public health failures.
d. microbes trying to cause disease.
e. travel.
...D
7. In the figure above, what is the endemic level of rotavirus infections?
a. 0%
b. Approximately 10%
c. Approximately 20%
d. 35%
e. The month of January
...B
8. A sexually transmitted disease is an example of
a. direct contact.
b. droplet transmission.
c. fomite.
d. vector.
e. vehicle transmission.
...A
9. Plague transmitted by a flea is an example of
a. direct contact.
b. droplet transmission.
c. fomite.
d. vector.
e. vehicle transmission.
...D
10. Pseudomonas bacteria colonized the bile duct of a patient following his liver transplant surgery. This is an example of a
a. communicable disease.
b. latent infection.
c. nosocomial infection.
d. sporadic disease.
e. viral infection
...C
During a 6-month period, 239 cases of pneumonia occurred in a town of 300 people. A clinical case was defined as fever ≥39oC lasting >2 days with three or more symptoms (i.e., chills, sweats, severe headache, cough, aching muscles/joints, fatigue, or feeling ill). A laboratory-confirmed case was defined as a positive result for antibodies against Coxiella burnetti. Before the outbreak, 2000 sheep were kept northwest of the town. Of the 20 sheep tested from the flock, 15 were positive for C. burnetti antibodies. Wind blew from the northwest and rainfall was 0.5 cm compared with 7 to 10 cm during each of the previous three years.



11. The case study is an example of
a. human reservoirs.
b. a zoonosis.
c. a nonliving reservoir.
d. a vector.
e. a focal infection.
...B
12. In the case study, the etiologic agent of the disease is
a. sheep.
b. soil.
c. C. burnetii.
d. pneumonia.
e. wind.
...C
13. In the case study, the method of transmission of this disease was
a. direct contact.
b. droplet.
c. indirect contact.
d. vector-borne.
e. vehicle.
...E
14. The graph in the figure above shows the incidence of polio in the United States. The period between 1945 and 1955 indicates
a. an endemic level.
b. an epidemic level.
c. a sporadic infection.
d. a communicable disease.
e. None of the above.
...B
15. Which of the following is not a condition of Koch's postulates?
a. Isolate the causative agent of a disease
b. Cultivate the microbe in the lab
c. Inoculate a test animal to observe the disease
d. Grow the organism in pure culture
e. Produce a vaccine
...E
16. The presence of Staphylococci on healthy skin helps to prevent pathogenic bacteria from colonizing and causing disease. This is an example of:
a. virulence.
b. pathogenicity.
c. antibiosis.
d. opportunism.
e. microbial antagonism.
...E
17. Which of the following processes depends on the F factor plasmid?
a. transformation
b. transduction
c. conjugation
d. translocation
e. recombination
...C
.


18. Symptoms of disease differ from signs of disease in that symptoms
a. are changes felt by the patient.
b. are changes observed by the physician.
c. are specific for a particular disease.
d. always occur as part of a syndrome.
e. None of the above.
...A
19. Influenza transmitted by an unprotected sneeze is an example of
a. indirect contact.
b. droplet transmission.
c. fomite.
d. vector.
e. vehicle transmission.
...B
20. Nosocomial infections occur in compromised patients.
a. True
b. False
...T
21. Insects can act as mechanical and biological vectors.
a. True
b. False
...T
40. Several inherited deficiencies in the complement system occurs in humans. Which of the following would be the most severe?
a. Deficiency of C3
b. Deficiency of C5
c. Deficiency of C6
d. Deficiency of C7
e. Deficiency of C8
A