Improved detection of spontaneous bacterial peritonitis with Bactec as compared with conventional culture methods. A prospective study.

Bacteriologic diagnosis of spontaneous bacterial peritonitis is difficult due to the low yield of isolating the bacteria from the ascitic fluid. We prospectively compared the conventional culture method with the nonradiometric Bactec culture system for the detection of bacteria in 20 episodes of spontaneous bacterial peritonitis. The ascitic fluid culture was positive by the conventional culture method in 25% and by Bactec in 79% of the episodes of spontaneous bacterial peritonitis (P = 0.004). Of culture-positive episodes, Gram-negative bacteria were detected by conventional cultures in 20% and by Bactec in 47%. Bactec culture system was significantly better than the conventional cultures for the detection of streptococci (viridans streptococci and Enterococcus fecalis), 33% versus 0 (P < 0.05). Conventional cultures did not detect bacteria that were not also detected by Bactec cultures. In conclusion, the Bactec nonradiometric culture method is superior to conventional cultures for the diagnosis of spontaneous bacterial peritonitis.