Gram – Joint fluid: 3+ (6-10/oif) neutrophils – 3+ (11-50/oif) gram negative bacilli (Kingella kingae) – Shipped August 12, 2019 – FINAL RESULTS


A simulated joint fluid sample collected from a 6-year-old with a sore knee and limping was sent to category A, B, C, and C1 laboratories.
Participants were expected to report the presence of neutrophils and gram-negative bacilli.


  1. The rapid and accurate examination of Gram stains prepared from joint fluids is critical to support patient treatment decisions. Laboratories need to be proficient at recognizing and reporting both cellular and bacterial components present in joint fluids on direct Gram stain.
  2. Kingella kingae may decolorize unevenly on Gram stain. If possible, it is important to indicate whether a single population of bacteria with a gram-variable appearance or two distinct populations of bacteria having different Gram-staining morphologies are present in a sample.


Full critique (PDF)

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