Seroepidemiology of astrovirus MLB1

Abstract

To determine the seroprevalence of astrovirus MLB1 (MLB1), an indirect enzyme-linked immunosorbent assay (ELISA) was established. MLB1 seropositivity was high in children <6 months old, decreased to a nadir at 12 to 23 months old, and increased to 100% by adulthood. MLB1 infection is common, and primary exposure occurs in childhood.

FIG 1

(A) Coomassie blue staining of a sodium dodecyl sulfate-polyacrylamide gel showing baculovirus-expressed His-tagged MLB1 (expected size, 88 kDa), MLB2 (expected size, 87 kDa), and MLB3 (expected size, 88 kDa) capsid proteins. (B) Western blot using polyclonal MLB1 peptide antibody (DW60) (1:500) against recombinant His-MLB1 capsid (5 ng) and polyclonal MLB2 peptide antibody (DW58) (1:2,500) against recombinant His-MLB2 capsid (100 ng). Mock, protein lysate from uninfected Sf9 cells.

FIG 2

ELISA results for MLB1. A total of 395 serum samples were assayed for antibodies against MLB1 capsid protein.

FIG 3

Effects of preincubation with MLB1, MLB2, MLB3, HAstV1, and RANK on MLB1 ELISA. Human serum samples were preincubated with each protein individually prior to the ELISA. The positive controls were polyclonal MLB1 peptide antibody (DW60) from each plate.

FIG 4

Effects of preincubation with MLB1, MLB2, MLB3, HAstV1, and RANK on MLB2 ELISA. Samples were preincubated with each protein individually prior to the ELISA.