Quantification of intracellular B henselae in erythroid differentiating HPCs. Freshly isolated HPCs were infected with B henselae (MOI 100) and gentamicin protection assays were performed on days 1, 6, and 13 after infection. The number of intracellular bacteria (% of inoculum) was calculated by counting the CFUs on CBA after 3 weeks of incubation. *Significant difference compared with day1(P < .01).