Raw data to: Longitudinal field study on Streptococcus suis serotype 2: After weaning serum IgG against suilysin (SLY) is of maternal origin but serum IgA-α-SLY is mainly self-generated

Many invasive Streptococcus suis strains secrete the cholesterol-dependent cytolysin suilysin (SLY). The objectives of this field study were to investigate the carriage of maternal IgG and IgA against SLY in piglets and the kinetics, as well as the bactericidal effect, of these antibodies. Serum levels of IgG-α-SLY and IgA-α-SLY in suckling piglets correlated with levels in colostrum and its uptake. Between the 2nd and 6th weeks of life, IgG-α-SLY decreased, whereas IgA-α-SLY showed a prominent increase. Linear mixed-effects models did not indicate that IgG-α-SLY or IgA-α-SLY had a significant effect on killing of Streptococcus suis serotype 2 in porcine blood in vitro.