A three-year old little girl presented to the emergency room with a fever of 102. She had a "runny nose" for several days and had eaten very little for two days. Her father had made her eat some cereal for breakfast, but she had vomited it immediately afterwards. She appears to be lethargic and not very well taken care of. She cries as you take her from her mother. You note several bruises on her forearms. Preliminary examination reveals a moderately red throat with white to yellow-gray tonsillar patches, a clear chest, and bilaterally enlarged cervical lymph nodes. She nods her head when you ask her if her throat hurts. Because she is mildly dehydrated, you admit her to the hospital.
Question 1 - Single Best Answer
What do you think is the site of her most immediate problem? Bugs Database
no one site is involved; you suspect child abuse pharynx lung kidney gastrointestinal
Question 2 - Single Best Answer
What is the most common cause of sore throat/pharyngitis? Bugs Database
viruses Streptococcus pyogenes (a bacteria) Haemophilus influenza (a bacteria) Candida albicans (a fungus) food allergies
Question 3 - Single Best Answer
What are the three most common bacterial causes of sore throat? Bugs Database
Streptococcus, Staphylococcus, and Bordetella Streptococcus, Staphylococcus, and Corynebacteria Streptococcus, Corynebacteria, and Neisseria Bordetella, Corynebacteria, Clostridia Neisseria, Corynebacteria, Clostridia
Question 4 - Single Best Answer
Which species of Neisseria causes pharyngitis? Bugs Database
meningitidis gonorrhoea sicca
Question 5 - Single Best Answer
What is the name of the pharyngitis caused by Corynebacteria? Bugs Database
strep throat diphtheria whooping cough scarlet fever toxic shock syndrome
Question 6 - Single Best Answer
How would you routinely diagnose the cause of a sore throat? Bugs Database
Gram stain of throat swab culture of throat swab on blood agar VDRL (serological test) viral culture culture of throat swab on Thayer-Martin media
Question 7 - Single Best Answer
What species of Streptococci cause a sore throat? Bugs Database
Streptococcus agalactiae Streptococcus faecalis Streptococcus pneumonia Streptococcus pyogenes Streptococcus viridans
Question 8 - Single Best Answer
What group of Streptococcus pyogenes causes sore throat? Bugs Database
Group A Group B Group C Beta hemolytic Type M
Question 9 - Single Best Answer
What structural component of the bacteria determines its group? Bugs Database
DNA RNA phospholipid carbohydrate protein
Question 10 - Single Best Answer
How do you differentiate the sore-throat-causing Streptococci (Group A from other Streptococci? Bugs Database
Group A Streptococci cause alpha hemolysis on blood agar Group A Streptococci cause beta hemolysis on blood agar Group A streptococci is resistant to bacitracin An India ink stain for a capsule would be positive for Group A Strep only the non-pathogens are Gram positive
Question 11 - Single Best Answer
Why do you test for bacterial causes of sore throat, in particular Streptococci, when most cases of pharyngitis are caused by viruses? Bugs Database
to earn more money for the lab you need to make the throat better with antibiotics if the cause is Streptococcus A strep throat can have very serious sequelae
Question 12 - Single Best Answer
What would you do in this child's case for diagnosis of her sore throat? Bugs Database
Gram stain of throat swab viral culture of throat wash throat swab on blood agar throat swab on Loeffler's media darkfield microscopy for N. gonorrhoea
The child is started on penicillin because you suspect Strep throat. A routine culture of a throat swab on blood agar shows some beta-hemolytic colonies. These colonies are restreaked on blood agar and tested with a bacitracin disc to confirm that they are Group A. They are. You also had a suspicion of child abuse, so ordered a culture for N. gonorrhoea. There is no sign of Neisseria gonorrhoea. The child does not improve in spite of the penicillin. In fact, on the third hospital day you note that she is extremely lethargic and is having trouble breathing. An examination of her throat reveals a grayish-yellow exudate covering her trachea. As you try to remove it, you note that it is tough, almost like a piece of chamois leather. You order a tracheostomy and another throat culture.
Question 13 - Single Best Answer
What specific culture do you order for a child with a pseudo-membrane in her throat? Bugs Database
throat swab on blood agar throat swab on chocolate agar throat swab on tellurate agar (Loeffler's media) special culture of throat washing for Haemophilus influenzae viral culture of throat washings
Question 14 - Single Best Answer
What therapy, in addition to penicillin, should be given to a child exhibiting a pseudo-membrane in the throat? Bugs Database
diphtheria toxoid human gamma globulin diphtheria antitoxin (DAT)
The culture is positive for C. diphtheria. The bacteria are confirmed as toxin producers. In spite of the aggressive surgical, antibiotic, and antitoxic therapy, the child died on the fifth hospital day of congestive heart failure.
Question 15 - Single Best Answer
What was the cause of the heart failure in this child with a co-infection of S. pyogenes and C. diphtheria? Bugs Database
penicillin allergy serum sickness diphtheria toxin rheumatic fever infection, but not this rapidly.. endocarditis
Question 16 - Single Best Answer
How did the diphtheria toxin cause heart failure in this child? Bugs Database
it is a neurotoxin and inhibited the release of the neurotransmitter at the neuromuscular junction it is a phospholipase that lysed the heart muscle cells it is a cytotoxin that prevented protein synthesis in the heart muscle cells, thereby causing their death it is a superantigen and caused a cascade of cytokine release it is an adenyl cyclase that increased the concentration of cAMP in the cells, interrupting their normal rhythm
Question 17 - Single Best Answer
How did the diphtheria toxin stop protein synthesis in this child's heart muscle cells? Bugs Database
it deregulated the cAMP metabolism it degraded the mRNA it ADP-ribosylated elongation-factor-2 it prevented the synthesis of mRNA it hydrolysed elongation-factor-2 thereby inhibiting translation
Question 18 - Single Best Answer
How could this child's death from diphtheria have been prevented? Bugs Database
earlier administration of antitoxin vaccination with diphtheria toxoid erythromycin instead of penicillin administration of digitalis vaccination with inactivated C. diphtheria