WBR0382
| Author | [[PageAuthor::Rim Halaby, M.D. [1]]] |
|---|---|
| Exam Type | ExamType::USMLE Step 1 |
| Main Category | MainCategory::Microbiology |
| Sub Category | SubCategory::Genitourinary |
| Prompt | [[Prompt::A 38 year old Caucasian male presents to the emergency department with fever and back pain that radiates to the inguinal area. Vital signs reveal a temperature of 38.5 degrees C (101 degrees F), heart rate of 98 beats per minute, and blood pressure measuring 122/88 mmHg. After appropriate work-up, the diagnosis of struvite stone is made. Stone culture and urine culture are performed; they reveal urea-splitting organism with swarming motility. What other characteristics does this organism have?]] |
| Answer A | AnswerA::Oxidase-positive, catalase-positive, urease-positive |
| Answer A Explanation | AnswerAExp::Proteus is not oxidase-positive. |
| Answer B | AnswerB::Oxidase-negative, catalase-negative, urease-positive |
| Answer B Explanation | AnswerBExp::Proteus is not catalase-positive |
| Answer C | AnswerC::Oxidase-positive, catalase-negative, urease-negative |
| Answer C Explanation | AnswerCExp::Proteus is none of the findings in option C. |
| 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 is not oxidase positive and not urease-negative. |
| Right Answer | RightAnswer::D |
| Explanation | [[Explanation::Proteus mirabilis is a common causative agent of struvite stones. It is an oxidase-negative, catalase-positive, urease-positive organism. It has a characteristic “swarming” motility in cultures. It is a known pathogen of the urogenital tract. Proteus is considered a urea-splitting organism, similar to Pseudomonas, Klebsiella, Staphylococcus, and Mycoplasma.
Educational Objective:
Proteus mirabilis is a common causative agent of struvite stones. It is an oxidase-negative, catalase-positive, urease-positive organism with characteristic “swarming” motility. |
| Approved | Approved::No |
| Keyword | |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |