"How it works" series: Linezolid

Linezolid (Zyvox) is one of only two antibiotics currently on the market in the oxazolidinone class (see what the other one is at the bottom of this article).  The unique structure makes cross resistance to other antibiotics like beta-lactams or vancomycin unlikely.  It works by binding to the 50S subunit of ribosomes in bacteria, preventing it from joining its partner 30S subunit.  In stopping the 50S subunit from binding the 30S subunit, the completed complex (70S) is never formed and therefore cannot begin to

Legionnaires' disease - reliability of urine antigen testing

A 58 year old male patient presents to the emergency room with shortness of breath for the last few days.  He also complains of chills, a cough, myalgia, and diarrhea.  His notable findings include WBC = 14 k/uL, Scr = 1.2 mg/dL, BUN = 27 mg/dL, BP = 132/76 mm Hg, RR = 30 breaths/minute, Tmax = 38.5⁰C, and O2sat = 92% on room air.  His chest x-ray reveals a patchy infiltrate suggestive of pneumonia.  Upon further questioning, the patient tells you he lives across the street from an apartment building where several people recently were diagnosed with Legionnaires' disease.  He has no recent exposure to any health care settings, has taken no antibiotics, was not recently incarcerated, is not immunocompromised, and has not recently traveled.  Can we use urine antigen testing to help guide our treatment of this patient's pneumonia?