View source for WBR0382

{{WBRQuestion
|QuestionAuthor={{Rim}}
|ExamType=USMLE Step 1
|MainCategory=Microbiology
|SubCategory=Genitourinary
|MainCategory=Microbiology
|SubCategory=Genitourinary
|MainCategory=Microbiology
|SubCategory=Genitourinary
|MainCategory=Microbiology
|MainCategory=Microbiology
|SubCategory=Genitourinary
|MainCategory=Microbiology
|SubCategory=Genitourinary
|MainCategory=Microbiology
|SubCategory=Genitourinary
|MainCategory=Microbiology
|SubCategory=Genitourinary
|MainCategory=Microbiology
|MainCategory=Microbiology
|SubCategory=Genitourinary
|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?
|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.

|AnswerA=Oxidase-positive, catalase-positive, urease-positive
|AnswerAExp=Proteus is not oxidase-positive.
|AnswerB=Oxidase-negative, catalase-negative, urease-positive
|AnswerBExp=Proteus is not catalase-positive
|AnswerC=Oxidase-positive, catalase-negative, urease-negative
|AnswerCExp=Proteus is none of the findings in option C.
|AnswerD=Oxidase-negative, catalase-positive, urease-positive
|AnswerDExp=Proteus mirabilis is correctly an oxidase-negative, catalase-positive, urease-positive organism 
|AnswerE=Oxidase-positive, catalase-positive, urease-negative
|AnswerEExp=Proteus is not oxidase positive and not urease-negative.
|RightAnswer=D
|Approved=No
}}