Detection and specificity of anti‐Staphy/ococcus intermedius secretory IgA in human tears

Abstract
Purpose:Secretory IgA (slgA) is the predominant immunoglobulin present in tears that protects the ocular surface against various antigens. Staphylococcus intermedius is a member of the normal ocular microbiota.Methods:The presence and the specificity of immunoglobulin A to S. intermedius was determined by fluorescent assay, ELISA and western blots.Results:Three immunodominant antigens of S. intermedius were detected of 145, 127 and 61 kDa. Staphylococcus inter‐med/us‐specific IgA cross reacted with Staphylococcus aureus but not with Gram negative bacteria.Conclusions:This indicates that specific IgA may play an important role in the protection of the eye by limiting the levels of Gram positive normal microbiota and defending against the more pathogenic S. aureus.