CLINICAL COMPARISON OF ISOLATOR, SEPTI-CHEK, NONVENTED TRYPTIC SOY BROTH, AND DIRECT AGAR PLATING COMBINED WITH THIOGLYCOLATE BROTH FOR DIAGNOSING SPONTANEOUS BACTERIAL PERITONITIS

Spontaneous bacterial peritonitis is a life-threatening complication o f cirrhotic ascites. Optimal patient management depends on the isolati on of the causal organism from ascitic fluid, To evaluate culture tech niques for the diagnosis of spontaneous bacterial peritonitis, we pros pectively compared three blood culture systems, the Isolator system, a lysis-centrifugation system, the Septi-Chek system, a biphasic cultur e system, and a nonvented tryptic soy broth system, all inoculated at the bedside, and our standard method of direct inoculation of specimen s after transport to the laboratory onto agar plates and into thioglyc olate broth. The results showed that the Septi-Chek and nonvented tryp tic soy broth systems each recovered statistically significantly more pathogens than either the Isolator system (P = 0.0084) or the standard method (P = 0.00098). The Isolator system recovered more pathogens th an the standard plate method, but this difference was not statisticall y significant. Both the Isolator system and the standard plate method recovered more contaminating microorganisms than the Septi-Chek or non vented tryptic soy broth system. The Isolator system required the most processing time compared with the processing times required by any ot her method.