25 terms

Microbiology Midterm #3 2012

A fastidious microbe is defined as one that
a) ferments lactose to produce acid and gas
b) grows in the intestines of mammals
c) is a gram negative coccobacillus
d) has to have all its CDs in alphabetical order
e) can only grow on particular types of media
Testing positive for the presence of Helicobacter pylori is associated with a higher risk of developing
a) pneumonia.
b) stomach ulcers.
c) diarrhea.
d) dysentery.
e) lockjaw.
Which of the following is not a typical step in a lytic bacteriophage infection?
a) Attachment
b) Lysis
c) Entry
d) Integration
e) Assembly
Members of family Enterobacteriaceae are all
a) lactose fermenters.
b) exotoxin producers.
c) Gram negative rods.
d) invasive pathogens.
e) obligate anaerobes.
Which of these patients would most likely have trouble with a Clostridium difficile infection?
a) Someone who eats a suspiciously bulged can of beans.
b) Someone who fails to clean a deep cut on their arm.
c) Someone who has been on antibiotics for 2 months.
d) Someone who steps on a rusty nail.
e) Someone who engages in unprotected sex with multiple partners.
What aspect of Francisella tularensis makes it particularly attractive as a potential bioweapon?
a) Infections may spread to rabbit populations.
b) They are Gram negative.
c) Infections are invariably lethal.
d) They form hardy endospores that are easy to disseminate.
e) An extremely low infectious dose.
Which of the following best explains why non-typhoidal salmonellosis and typhoid feer produce such different symptoms?
a) Non-typhoidal Salmonella lacks an endotoxin.
b) Production of an exotoxin.
c) Migration of the bacteria from the intestines to other organs.
d) Cell to cell movement without exposure to the immune system.
e) Invasion of the gut epithelium.
The bacterium that produces many of our modern antibiotics is typically found
a) in the soil.
b) in the ocean.
c) in the air.
d) in our hospitals.
e) in our gastrointestinal tracts.
Which of the following would you not be likely to observe in a patient who is suffering from both Lyme disease and syphilis?
a) A bullseye rash around the site of a tick bite.
b) A chancre on or near the genitals.
c) A patchy rash on various sites around the body.
d) Extremely watery diarrhea.
e) Gram-negative spirochette bacteria.
Oral rehydration therapy makes use of a(n) _________ solution to treat dehydration.
a) protein
b) intravenous saline
c) sugar and salt
d) antibiotic
e) antitoxin
Which of the following features of Pseudomonas explains why it is generally limited to opportunistic infections, particularly of injuries such as burns?
a) It does not produce a toxin and thus has difficultly causing harm.
b) It is highly sensitive to most antiseptics and disinfectants.
c) It has a limited growth range and is rarely found in the environment.
d) It is an obligate anaerobe and thus requires deep wounds to grow.
e) It is highly vulnerable to attack by the immune system.
A troubling sign of Neisseria meningitidis bacteremia is the appearance of ________ on te patient's body.
a) puncture wounds
b) block sweat glands
c) hairs
d) petechiae
e) chancres
A patient with a persistant cough tests positive for the presence of Bordetella pertussis. He is prescribed antibiotics, but his cough persists for weeks afterwards. Which of the following helps most to explain why his symptoms continue for so long.
a) Pertussis toxin causes excess mucus production in the lungs.
b) Bordetella are obligate aerobes.
c) Tracheal toxin kills ciliated epithelium.
d) Bordetella are Gram negative bacteria and have an associated endotoxin.
e) Bordetella grows non-invasively.
Which of the following best describes how Corynebacterium diptheriae usually causes disease?
a) Exotoxins produced during an invasive infection of the intestines.
b) Exotoxins produced during a non-invasive infection of the throat.
c) Invasive infection on the intestines without exotoxin production.
d) Exotoxins produced during a non-invasive infection of the intestines.
e) Invasive infection of the meninges following an infection of the throat.
Which of the following best explains why antibiotic treatment of tuberculosis must be carried out over a long period of time?
a) The symptoms do not become apparent until very late in the disease.
b) Antibiotics require growth in order to kill cells.
c) Remnants of bacterial cells may remain in the body for months.
d) Rapid treatments may increase risk of stomach cancer.
e) Long periods of treatment decrease the risk of resistance arising.
Which of the following organisms is incapable of utilizing glucose as a carbon source, even under aerobic conditions?
a) Pseudomonas aeruginosa
b) Bordetella pertussis
c) Alcaligenes faecalis
d) Escherichia coli
e) Clostridium tetani
In establishing a clean room for immune-compromised patients, you install a standard bacterial filter on the ventilation system. Which of the following diseases could potentially still spread through the ventilation system?
a) Pneumonic plague.
b) Walking pneumonia.
c) Chlamydia.
d) Lyme disease.
e) Legionnaire's disease.
If someone is suspected of having contracted botulism, which of the following is the first and most important treatment?
a) Administration of appropriate antibiotics.
b) Administration of an antitoxin.
c) Use of a hyperbaric chamber (high concentration of oxygen).
d) Debridement of the wound.
e) Hydration.
Which of the following describes a type of infection that can be caused by different strains of E. coli?
a) Urinary tract infection.
b) Invasive infection of the intestines.
c) Non-invasive growth in the intestines and production of an exotoxin.
d) Production of a "Shiga-like" toxin in the intestines.
e) All of the above can be caused by E. coli.
Before it was known that influenza (the flu) is a viral disease, which bacterial genus was mistakenly thought to be the cause?
a) Chlamydia
b) Mycoplasma
c) Pseudomonas
d) Haemophilus
e) Neisseria
Which of the following measure is most important in preventing the spread of Shigella?
a) Avoiding burn injuries.
b) Avoiding puncture wounds.
c) Keeping up-to-date vaccinations.
d) Clean water and food sources.
e) Avoiding unprotected sex with multiple partners.
Which of the following anti-viral drugs would you guess to be least likely to cause side-effects in patients?
a) A drug that stops mitochondrial activity.
b) A drug that blocks ribosome function.
c) A drug attacking peptidoglycan synthesis.
d) A drug that degrades double-stranded DNA.
e) A drug attacking double-stranded RNA.
Which of the following is an example of an obligate intracellular parasite?
a) Escherichia coli.
b) Clostridium botulinum.
c) a bacteriophage.
d) Corynebacterium diphtheriae.
e) Both C and D are correct.
Which of the following is a shared feature of Salmonella typhi, Legionella pneumophila, and Francisella tularensis?
a) They produce potent exotoxins.
b) They form endospores.
c) They are Gram positive rods.
d) They are common causes of respiratory tract infections.
e) They invade macrophages.
Which of the following organisms does NOT cause a disease primarily affecting the respiratory tract?
a) Bordetella pertussis
b) Legionella pneumophilia
c) Mycobacterium tuberculosis
d) Vibrio cholerae
e) Mycoplasma pneumoniae