A comparison of lysis centrifugation, pour plate, and conventional blood culture methods in the diagnosis of septicaemic melioidosis.

AIMS: To determine whether quantitative blood culture methods could improve the diagnosis of septicaemic melioidosis.

METHODS

A comparison of conventional broth based blood cultures, a pour plate method, and a commercial lysis centrifugation (Isolator 10) blood culture system was conducted in 71 Thai patients with severe melioidosis. The time to identification of B pseudomallei was recorded for each method.

RESULTS

42 patients (59%) were septicaemic. Compared with conventional blood culture, the Isolator and pour plate methods had sensitivities of 81% and 61%, respectively. The median times to a positive culture were: Isolator 39.3 hours, pour plates 45.5 hours, broth culture 61.8 hours (p < 0.001 Isolator v broth). There was a significant inverse correlation between Isolator tube or pour plate quantitative counts and time to detection (r = -0.44 and -0.57, respectively). Mortality was higher in patients who were septicaemic.

CONCLUSIONS

Routine use of one of these quantitative methods, in addition to conventional broth culture, may lead to earlier diagnosis of septicaemic melioidosis.