TABLE 3 

Time to detection of microorganisms with different culture mediaa

Culture mediumMedian time (h) to detection (IQR)P valueb
Complete cohort (n = 369)Met IDSA criteria for PJI
No (n = 252)Yes (n = 117.0)
Aerobic agar41 (21, 63)49 (45, 95)33 (21, 62)0.003
Anaerobic agar62 (43, 144)144 (50, 163)52 (43, 140)0.3
Thioglycolate65 (43, 92)160 (65, 195)64 (43, 90)0.01
Aerobic blood culture bottle21 (14, 45)27 (21, 42)21 (13, 45)0.8
Anaerobic blood culture bottle23 (16, 47)52 (24, 147)22 (14.5, 38.5)0.02
  • a Time to detection was measured from the time the specimen was received in the laboratory until the time a microorganism was detected. In the case of thioglycolate broth and blood culture bottles, this was the time the thioglycolate broth was recorded as cloudy or the bottle gave a positive result with an organism detected by Gram staining, respectively.

  • b P value comparing time to positivity for each medium according to whether cases met IDSA criteria for PJI.