The y-axis represents the MFI, divided by 1000. Boxplots show median MFI (IQR) from healthy controls and Enterococcus bloodstream infection controls. Longitudinal antibody responses in patients with K pneumoniae bloodstream infection are represented by individual lines, with each datapoint corresponding to a single sample at a given timepoint. The x-axis denotes the number of days since the first positive blood culture for K pneumoniae (day 0). Blue lines indicate antibody responses of patients with K pneumoniae bloodstream infection caused by infection with the homologous O-specific polysaccharide type, whereas orange lines represent patients with K pneumoniae bloodstream infection caused by heterologous O-specific polysaccharide subtype. Grey lines represent patients with K pneumoniae bloodstream infection caused by other O-specific polysaccharide serotypes. The red lines represent the locally weighted scatterplot smoothing regression applied to the blue lines, with 95% CIs shown as shaded blue areas. The solid black line represents the median of healthy controls, and the dashed black line represents the median of Enterococcus spp bloodstream infection controls. BC=Enterococcus bloodstream infection controls. HC=healthy controls. K pneumoniae=Klebsiella pneumoniae. MFI=median fluorescence intensity.
