FIG. 4.

Reactivity of H. somnus strain 2336-R and phase variant 738 to LOS MAb determined by ELISA following growth with or without CMP-NeuAc. Bacteria were grown to 10⁹ CFU/ml in CTT, diluted 1:10 in fresh CTT containing 50 μg of CMP-NeuAc per ml, and shaken for 3 h at 37°C. LOS was extracted, and 1 μg/well was used as antigen in the ELISA with MAb 5F5.9 (strain 738) or 3F11 (strain 2336-R). For some assays, 5 μg of LOS was pretreated with 5.5 U of V. cholerae neuraminidase for 1 h at 37°C. +S, LOS from cells grown with CMP-NeuAc; +N, LOS treated with neuraminidase; +S +N, LOS from cells grown with CMP-NeuAc and treated with neuraminidase. Error bars indicate standard deviations.