CHECKPOINT Flashcards
A 45/M diabetic, presents to the ER with warm, tender, fluctuant
erythematous mass. He is febrile, tachycardic. Blood culture yields
Gram positive cocci, which grow in Mannitol salt agar. He is given a
treatment course with Methicillin, but he does not improve. Which
genetic mechanism is responsible?
A. Acquisition of the mecA gene, which encodes an altered
penicillin-binding protein (PBP2a)
B. C. Mutation in the npxB gene that affects cell wall synthesis
Transfer of the vanA gene from vancomycin-resistant
enterococci (VRE)
D. Integration of the blaZ gene encoding beta-lactamase
production
A. Acquisition of the mecA gene, which encodes an altered
penicillin-binding protein (PBP2a
A 70/F chronic kidney disease on hemodialysis, presents to the ER
with fever, chills and pain on catheter insertion site. On PE, she is
septic. There is erythema tenderness and purulent discharge at
catheter insertion site. Blood cultures are positive for Coagulase
negative, Gram positive cocci. Which of the following is TRUE
regarding its pathogenicity?
A. Coagulase helps build insoluble fibrin capsule
B. Alpha toxin causes cell hemolysis
C. Biofilm formation encases it in extracellular matrix
D. Protein A prevents complement activation
C. Biofilm formation encases it in extracellular matrix
A 50/M uncontrolled DM came in for 1 wk fever and chills. He has
shallow ulcer over plantar aspect of right foot, with erythema warmth
and swelling. Blood cultures positive for gram positive cocci in chains.
The isolate has a clear area of hemolysis in blood agar. It grows in the
presence of a bacitracin disc. Pyrrolidonyl arylamidase (PYR) test is
negative. Which of the ff organisms is most likely the isolate?
A. Streptococcus pyogenes
B. Streptococcus agalactiae
C. Streptococcus pneumoniae
D. Viridans group Streptococcus
E. Enterococcus faecalis
B. Streptococcus agalactiae
A 32/F presents with fever, sore throat and swollen lymph nodes. On
examination, she has white exudates on her tonsils, palatal petechiae
and tender cervical lymph nodes. Which of the following
immunologic complications can occur?
A. Rheumatic fever
B. Gastric lymphoma
C. Polyarteritis nodosa
D. Cryoglobulinemic vasculitis
A. Rheumatic fever
40/M Mail delivery man consulted for high grade fever, cough and
shortness of breath. VS T 40C, BP 90/60, HR 125, RR 28, spO2 90%
on O2 6L/min. He has slow mentation, tachycardia, dec breath
sounds over left base. CXR shows pleural effusion on left. Diagnostic
thoracentesis shows bloody effusion. GS likely shows _?
A. Gram positive cocci in pairs
B. Anaerobic Gram positive rods
C. Gram negative coccobacilli
D. Aerobic gram positive rods
E. Small spherules
D. Aerobic gram positive rods
60/M admitted at the ICU had been on Piperacillin tazobactam and
Clindamycin. Towards end of course, he experienced profuse watery
diarrhea, abdominal cramping and fever. VS T 38, HR 120, BP 80/55,
RR 20, spO2 95% RA. PE showed diffuse abdominal tenderness. WBC
20,000 cells/uL, lactic acid 5 mmol/L. SFA showed nonobstructive gas
pattern. What organism is the likely cause?
A. Clostridium difficile
B. Escherichia coli (EHEC)
C. Salmonella enterica
D. Shigella dysenteriae
A. Clostridium difficile
A 45/M known alcoholic came in for 3 day history of fever, chills and
left hand pain, redness and swelling. He got nicked on a fishing trip at
the lake 1 week prior. On examination, there is an erysipelas-like
cellulitis over the left hand. Which of the following organisms is most
likely the cause of this patient’s illness?
A. Mycobacterium marinum
B. Vibrio vulnificus
C. Aeromonas hydrophila
D. Erysipelothrix rhusiopathiae
E. Sporothrix schenckii
D. Erysipelothrix rhusiopathiae
A 5 year old child is brought to the ER for 3 day history of fever, sore
throat, hoarse voice and difficulty swallowing. On PE, he is febrile. The
neck is swollen, and there is grayish white pseudomembrane on
tonsils and pharynx, which bleeds when scraped. There is also
cervical lymphadenopathy. Which of the following is the most likely
diagnosis and appropriate management?
A. Acute streptococcal pharyngitis; treat with penicillin and
supportive care
B. C. Mononucleosis; treat with supportive care and corticosteroids
Laryngotracheobronchitis (Croup); treat with nebulized
epinephrine and steroids
D. Diphtheria; initiate antitoxin therapy and antibiotics (e.g.,
penicillin or erythromycin), and secure the airway
D. Diphtheria; initiate antitoxin therapy and antibiotics (e.g.,
penicillin or erythromycin), and secure the airway
A 3 day old neonate is admitted to the NICU with respiratory distress,
poor feeding and temperature instability. The mother reportedly
lives as a farm hand and drinks milk fresh from the cow. The baby is
septic. On PE, there is hepatosplenomegaly, jaundice, petechiae and
purpura. Ct scan shows multiple microabscesses in liver, spleen and
lungs. Which of the following is the likely cause?
A. Group B streptococcus
B. Listeria monocytogenes
C. Escherichia coli
D. Herpes simplex virus
B. Listeria monocytogenes
58/M COPD on chronic steroids, presents with 3 week history of
fever, cough, shortness of breath, night sweats and weight loss. CXr
shows cavitary lesion on right lower lobe. Sputum has Gram positive,
partially acid fast, branching filaments. What is the most appropriate
treatment?
A. Amoxicillin clavulanate
B. Ciprofloxacin and vancomycin
C. Trimethoprim sulfamethoxazole
D. Isoniazid and rifampin
C. Trimethoprim sulfamethoxazole
