WBR0507

Author	[[PageAuthor::Serge Korjian M.D., Gonzalo A. Romero, M.D. (Reviewed by Alison Leibowitz)(Reviewed by Serge Korjian)]]
Exam Type	ExamType::USMLE Step 1
Main Category	MainCategory::Embryology, MainCategory::Microbiology, MainCategory::Pharmacology
Sub Category	SubCategory::Infectious Disease
Prompt	[[Prompt::A 2-year-old girl is brought to the pediatrician because her mother is concerned that her teeth have turned a dark shade of gray since her last check-up. The mother explains that her daughter has been developing normally, but she recently started refusing formula. She also reports that approximately 2 months ago, the child had an episode of cough and sore throat for which she gave her some left-over antibiotics she had at home. Physical exam is unremarkable except for dark gray stains apparent mostly across the front teeth. Which of the following was most likely mechanism of action of the drug used in this patient?]]
Answer A	AnswerA::Prevents attachment of aminoacyl-tRNA to 30S ribosomal subunit
Answer A Explanation	AnswerAExp::Tetracycline
Answer B	AnswerB::Inhibits the formation of initiation complex
Answer B Explanation	AnswerBExp::Aminoglycosides
Answer C	AnswerC::Inhibits protein synthesis by binding to the 50S ribosomal subunit
Answer C Explanation	AnswerCExp::Clindamycin
Answer D	AnswerD::Inhibits the translocation by binding to the 23S ribosomal subunit
Answer D Explanation	AnswerDExp::Macrolide
Answer E	AnswerE::Inhibits protein elongation by blocking peptidyl-transferase
Answer E Explanation	AnswerEExp::Chloram
Right Answer	RightAnswer::A
Explanation	[[Explanation::Tetracyclines Educational Objective: References: ]]
Approved	Approved::Yes
Keyword
Linked Question	Linked::
Order in Linked Questions	LinkedOrder::