Individual boxplots with IQRs display IgG, IgM, and IgA antibody responses for healthy controls, Enterococcus bloodstream infection controls, and the highest antibody responses from patients with K pneumoniae bloodstream infection in response to O1v1, O1v2, O3/O3a, and O3b antigens. The x-axis categorises plasma samples sourced from healthy controls, Enterococcus bloodstream infection controls, and patients infected with K pneumoniae with various O-specific polysaccharide types. The "Other" category includes O-specific polysaccharide types O4, O12, and unidentified O-specific polysaccharide. The y-axis represents the fold change in antibody responses relative to healthy controls, calculated as the MFI divided by the median MFI of healthy controls. Specifically, the results from patients infected with K pneumonia strains that have homologous or heterologous O-specific polysaccharide subtypes compared with the antigen are highlighted with yellow backgrounds. p values shown in the figure indicate the higher p values as determined by MannWhitney U test, comparing K pneumonia bloodstream infection with both healthy controls and Enterococcus bloodstream infection controls. Detailed information regarding the number of samples is available inappendix 1 (p 31). K pneumoniae=Klebsiella pneumoniae. MFI=median fluorescence intensity.
