TABLE 3.

In vitro survival of BCG and DPP in murine peritoneal macrophages from wild-type mice, with and without IFN-γ plus LPS^a

Bacterial strain and treatment	Colony countb				Pc
	Mean		SE
	24 h	5 days	24 h	5 days
BCG
None	1,196	407	285	52.76	0.088
IFN-γ + LPS	1,088	235	289	68.5	0.0064
DPP
None	1,670	13,189	184.29	461.5	0.0001
IFN-γ + LPS	3,371	9,948	552	382	0.006

^aThioglycolate (3%) was injected into the peritoneal cavities of wild-type C57BL/6 mice. Four days after injection, animals were anesthetized with isoflurane. Peritoneal cavities were washed with ice-cold RPMI to recover peritoneal macrophages. Peritoneal macrophages were infected with BCG or DPP at an MOI of 10:1. At 2 h after infection, unphagocytosed organisms were removed. Infected macrophages were maintained in RPMI containing 10% fetal bovine serum or in RPMI containing 10% fetal bovine serum, IFN-γ (100 U/ml), and LPS (1 μg/ml).

^bIntracellular colony counts were determined by plating lysed cultures on Middlebrook 7H11. Data are averages from three experiments.

^cCalculated with the Statview program.