TABLE 5.

Effect of protein synthesis inhibition on M. tuberculosis invasion of macrophages

M. tuberculosis strain	Conditiona	Uptake (% of inoculum) of M. tuberculosis in the presence or absence of antibioticb
		Absence	Presence
H37Rv	Laboratory	18 ± 4	17 ± 3
	pH 6.0	56 ± 9	21 ± 4c
	Anaerobiosis	57 ± 11	23 ± 5c
Erdman	Laboratory	23 ± 7	22 ± 2
	pH 6.0	61 ± 6	27 ± 5c
	Anaerobiosis	58 ± 7	26 ± 4c

^aBacteria were exposed to the conditions for 4 h and then incubated with macrophages in the presence of 10% heat-inactivated serum. Results are means ± standard deviations.

^bBacteria were treated with rifampin (0.5 μg/ml) as described in Materials and Methods.

^cP < 0.05 compared with invasion without prior incubation with antibiotic.