Joe Gloveless

(Modified from MMWR, Vol 51, p 279, 2002)

On Feb 28 a laboratory assistant, to be known hereafter only as Joe, who worked for a laboratory involved in processing suspected bioterrorism samples, cut a small bump on his right jaw while shaving. It bled briefly and then became itchy and irritated. On March 1, Joe assisted a co-worker in moving samples from a biological safety cabinet to a freezer. The co-worker had transferred the isolates from agar plates to the vials. Without gloves, Joe took the vials from the co-worker, placed them in the freezer and washed his hands with soap and water. During the next several days, his facial wound increased in size and developed a black, somewhat recessed, scab. He also reported right cervical adenopathy, a low-grade fever, and swelling and erythema on his right cheek that spread down to his neck.

Question 1 - Single Best Answer

What are some of the agents that a bioterrorism laboratory might be handling?   

A) Bacillus anthracis
B) Yersinia pestis
C) Clostridium botulinum
D) Francisella tularensis
E) all of the above

Question 2 - Single Best Answer

Which of the agents listed in the above question can cause infections of wounds?   

A) Bacillus anthracis
B) Yersinia pestis
C) Clostridium botulinum
D) Francisella tularensis
E) more than one of the above

Joe's wound was swabbed and the swab streaked on a nutrient agar plate and a blood agar plate. The plates were incubated aerobically and anaerobically. A chest x-ray was also done. The aerobic agar plates grew colonies that were Gram+ rods.

Question 3 - Single Best Answer

What bacteria could these Gram+ rods be?   

A) Clostridium botulinum
B) Clostridium tetani
C) Francisella tularensis
D) Bacillus anthracis
E) Staphylococcus epidermidis

Question 4 - Single Best Answer

What disease does Bacillus anthracis cause?   

A) botulism
B) anthrax
C) hemorrhagic fever
D) toxic shock syndrome
E) plague

Question 5 - Single Best Answer

Does finding aerobic Gram+ rods in his wound mean he has anthrax?   

A) yes
B) no

Question 6 - Single Best Answer

What other bacteria are aerobic Gram+ rods?   

A) Clostridium botulinum and Bacillus cereus
B) Bacillus subtilus and Staphylococcus aureus
C) Bacillus cereus and Corynebacterium diphtheriae
D) Corynebacterium diphtheriae and Streptococcus pyogenes
E) Listeria monocytogenes and Yersinia pestis

Question 7 - Single Best Answer

What would Bacillus anthracis look like on a blood agar plate?   

A) Hemolytic
B) Non-hemolytic
C) black

The bacteria from Joe's wound was shown to be non-motile and non-hemolytic, both of which are consistant with it being Bacillus anthracis.

Question 8 - Single Best Answer

What other method might be used to identify the anthrax agent?   

A) PCR
B) Wasserman test
C) Cold hemaglutinnins

Because of the culture results Joe was admitted to the hospital and given two intravenous antibiotics pending antimicrobial susceptibility testing.

Joe's radiograph demonstrated POSSIBLE fullness of the mediastinum.

Question 9 - Single Best Answer

Why is this worrisome?   

A) It means that his anthrax has spread to the lungs
B) It means he also has pneumonia
C) It is characteristic of inhalation anthrax
D) It means that he has a birth defect that will make him highly susceptible to anthrax so he shouldn't be working in a bioterrorism laboratory.

Later, a CAT scan showed that there was no widening of the mediastinum.

Question 10 - Single Best Answer

Besides inhalation and cutaneous anthrax, what other form of anthrax is there?   

A) diarrheal
B) neurological
C) gastrointestinal
D) encapsulated

Question 11 - Single Best Answer

Which of the three forms of anthrax is the most serious?   

A) cutaneous
B) gastrointestinal
C) inhalation

Question 12 - Single Best Answer

What are the initial signs of inhalation anthrax?   

A) meningitis
B) respiratory failure
C) bloody diarrhea
D) mild fever, muscle aches, malaise

Question 13 - Single Best Answer

What is/are the virulence factor(s) found associated with Bacillus anthracis?   

A) toxin
B) capsule
C) flagella
D) toxin and capsule
E) hemolysin

Question 14 - Single Best Answer

What is unusual about the capsule of Bacillus anthracis?   

A) it is polysaccharide
B) it is peptidoglycan
C) it is not a polysaccharide
D) it is not antiphagocytic
E) it is made of O-antigen

Question 15 - Single Best Answer

What is the composition of the current anthrax vaccine?   

A) the capsule
B) the toxin
C) a toxoid
D) a filtered cell extract
E) whole cells of B. anthracis

The anthrax toxin is composed of three parts, the lethal factor (LF), the edema factor (EF), and the protective antigen (PA). The PA is the part that binds to the cells (the host's cells), the EF is an adenyl cyclase, and the activity of the LF has not yet been characterized. The EF and LF are bound to the PA and are injected into cells after the PA attaches to the cells

Question 16 - Single Best Answer

Antibodies to which part of the toxin provide protection to disease?   

A) LF
B) EF
C) PA

Even though B. anthracis was isolated from Joe's wound, this was not considered proof that he had anthrax as the bacteria could have just been a contaminant of his wound. The spores could have been in the wound and germinated on the agar plate -- but it was confirmed that he had the disease anthrax by serial serology. It was found that he had a 4 fold rise in the titer of an antibody to a component of B. anthracis at about 8 weeks after his symptoms first appeared.

Question 17 - Single Best Answer

What did Joe and his fellow workers do wrong that got him in trouble?   

A) Didn't wear gloves
B) Didn't cover skin defects with impermeable bandages
C) Used alcohol instead of bleach to disinfect the surface of vials containing anthrax bacilli
D) All of the above

After anthrax, it is considered that small pox is the most likely agent to be used by terrorists.