A 41-year-old man comes to the Emergency Department with three days of swelling and pain in the right knee, with functional impotence and fever Two weeks earlier he had had a self-limited diarrhea. On examination there is joint effusion, so we proceed to perform an arthrocentesis and obtain 50 cc of cloudy liquid, with decreased viscosity and the following analytical parameters: leukocytes 40. 000/microL (85% of neutrophils), glucose 40 mg/dL, absence of crystals, Gram stain: no microorganisms are observed. Which of the following statements about this patient is WRONG:
A gram negative stain never rules out the presence of infection.
Treatment with cloxacillin and ceftriaxone should be initiated pending the result of the fluid culture.
It is advisable to perform daily arthrocentesis to relieve symptoms and prevent joint destruction.
If the culture is negative, it is likely to be reactive arthritis.
Negative Gram stain rules out septic arthritis.
A gram negative stain never rules out the presence of infection.