Clearance of viable Calmette-Guèrin bacillus by the in vitro isolated and perfused rat liver.

Liver efficiency in clearing circulating BCG (Clamette-Guèrin bacillus) was studied using the isolated rat liver. Bacteria were added to the perfusate at a concentration of 1 X 10(6) cells/ml, and the medium was then sampled at subsequent intervals for 6 hours in 2 perfusions and for 1 hour in 7 perfusions. At the end of all perfusions, liver and bile samples were obtained and used for viable bacterial counts. For each perfusion the bactericidal activity which might have been exerted by serum present in the perfusate was also investigated. About 95% of BCG disappeared from the perfusate after 6 hours of perfusions, and 90% after 1 hour. Recovery of viable bacteria in the liver at 60 minutes averaged 80% of the inoculum. Recovery in bile was negligible. Control experiments indicated that extrahepatic factors in possible reduction of bacterial concentration in the perfusate did not interfere with hepatic removal, per se.