TABLE 2.

Deletion of hbhA does not affect the adherence of M. tuberculosis to J774.A1 cells^a

M. tuberculosis strain	Serum treatment	Mean log10 CFU ± SD per J774.A1 cell	% of inoculum bound to J774.A1 cells
H37Rv parent	None, inoculum	6.11 ± 0.31	NA
H37Rv parent	None	4.25 ± 0.24	1
H37Rv parent	NHS	5.76 ± 0.24	45
ΔhbhA mutant	None, inoculum	5.90 ± 0.10	NA
ΔhbhA mutant	None	4.34 ± 0.25	3
ΔhbhA mutant	NHS	5.46 ± 0.25	36

^aH37Rv and the ΔhbhA mutant were incubated in either no serum or 5% NHS for 40 min at 37°C. The M. tuberculosis cells, still in their respective serum treatments, were then used to infect J774.A1 cells at an MOI of 1:1 for 1 h at 37°C. After 1 h, the J774.A1 cells were washed, lysed, and plated for mycobacteria CFU counts on 7H11 agar. The experiment was performed in duplicate wells in each of two separate experiments. Mean log₁₀ CFU ± SD for one representative experiment is shown. The values for the no serum treatment and the NHS treatment are statistically significant within each strain (P ≤ 0.04) but not between strains (P > 0.10). Student's t test was used for statistical analysis. NA, not applicable.