Milk from Brazilian women presents secretory IgA antibodies and neutralizes rotavirus G9P[5]

Abstract

Objective: To verify the presence of anti-rotavirus serotype G9P[5] SIgA and the virus neutralization capacity of milk samples from Brazilian women. Methods: SIgA antibody levels reactive to rotavirus G9 were determined in 30 maternal milk samples by enzyme-linked immunosorbent assay (ELISA) using purified virus suspensions. The samples’ capacity to neutralize rotavirus G9P[5] was analyzed using the MA-104 cells neutralization assay. Results: Great individual variations were observed regarding the SIgA levels and neutralization titers, but all samples showed some G9P[5] neutralizing ability. A highly significant positive correlation was observed between antibody levels and neutralization titers. Conclusions: The high correlation between anti-rotavirus antibody levels and neutralizing capacity of the milk samples suggests a possible protective role of these antibodies against infection. These results also support the encouragement of the breast-feeding practice.

Keywords

• Human milk
• Rotavirus
• Secretory IgA
• Rotavirus neutralization