Polymorphonuclear leukocytes (PMNL) uptake of
Klebsiella pneumoniae. Uptake of opsonized K1, K5, and non-HMV K. pneumoniae with normal serum (A and B) or heat-inactivated serum (C and D) from seropositive (A and C) or seronegative (B and D) donors by African Green monkey (AGM) PMNL was measured in vitro as described. The results are expressed as fold-uptake when compared to PBS opsonized bacteria. The error bars represent standard errors for triplicate samples, and the results shown are representative of three independent experiments. Asterisk indicates significant difference between treatments, p ≤ 0.05; Double asterisk indicates significant difference between treatments, p ≤ 0.001; Equal to indicates similarity between treatments, p > 0.05.