WBR0382
| Author | [[PageAuthor::Rim Halaby, M.D. [1] (Reviewed by Alison Leibowitz)]] |
|---|---|
| Exam Type | ExamType::USMLE Step 1 |
| Main Category | MainCategory::Microbiology |
| Sub Category | SubCategory::Genitourinary |
| Prompt | [[Prompt::A 38-year-old male presents to the ER with complaints of fever and back pain, radiating to the inguinal area. Vital signs reveal a temperature of 38.5 °C, heart rate of 98 beats per minute, and blood pressure measuring 122/88 mmHg. Following appropriate work-up, you diagnose him with struvite stone and preform a stone and urine culture. The cultures reveal a urea-splitting organism with swarming motility. Which of the following characteristics most likely corresponds to this organism?]] |
| Answer A | AnswerA::Oxidase-positive, catalase-positive, urease-positive |
| Answer A Explanation | AnswerAExp::''Proteus mirabilis'' is not oxidase-positive. |
| Answer B | AnswerB::Oxidase-negative, catalase-negative, urease-positive |
| Answer B Explanation | AnswerBExp::''Proteus mirabilis'' is not catalase-positive. |
| Answer C | AnswerC::Oxidase-positive, catalase-negative, urease-negative |
| Answer C Explanation | AnswerCExp::''Proteus mirabilis'' is not oxidase-positive, catalase-negative, nor urease-negative. |
| Answer D | AnswerD::Oxidase-negative, catalase-positive, urease-positive |
| Answer D Explanation | AnswerDExp::''Proteus mirabilis'' is correctly an oxidase-negative, catalase-positive, urease-positive organism. |
| Answer E | AnswerE::Oxidase-positive, catalase-positive, urease-negative |
| Answer E Explanation | AnswerEExp::''Proteus mirabilis'' is not oxidase positive nor urease-negative. |
| Right Answer | RightAnswer::D |
| Explanation | [[Explanation::Proteus mirabilis, a causative agent of struvite stones, is an oxidase-negative, catalase-positive, urease-positive organism, which has a characteristic “swarming” motility in cultures. Proteus mirabilis is a known pathogen of the urogenital tract. Other examples of urea-splitting organisms are Pseudomonas, Klebsiella, Staphylococcus, and Mycoplasma. Educational Objective: |
| Approved | Approved::Yes |
| Keyword | |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |