Comparison of classical methods versus BACTEC blood culture system for culture of normally sterile body fluids

Background - Presence of microorganisms in sterile body sites leads to life-threatening infections. For early and accurate diagnosis of those infections, cultures of the sterile fluids have to be done. These cultures can not always detect the causative agents due to insufficent number or fastidious growing of the probable microorganisms in the material. Objectives - In this study, it was aimed to compare sterile body fluid cultures which had been processed with both conventional culture methods and BACTEC automatized blood culture system retrospectively. Material and Methods - A total of 138 body fluid cultures were compared retrospectively from the laboratory records. Results - Amongst the specimens, 122 cultures were negative. Nine of the rest 16 specimens were positive with both culture methods and seven cultures were positive with BACTEC only. None of the specimens which were negative in BACTEC system revealed positive with the conventional method. BACTEC detected significantly higher number of positivity (P<0.001). No significant difference was found between the methods due to contamination (P=0.183). Conclusion - In conclusion, our study shows that inoculation of the sterile body fluid specimens into blood culture bottles and incubation of them in BACTEC system as well as culturing with conventional methods increase the detection rate of probable causative agents.