Escherichia coli administered into pig amniotic cavity appear in fetal airways and attract macrophages into fetal lungs

Abstract

Escherichia coli (2 x 10(4) bacteria) of the non-pathogenic O86 strain or enteropathogenic O55 strain were administered into the pig amniotic cavity at 79 to 86 days of gestation for six or ten hours. Translocation of bacteria into fetal lungs was confirmed by cultivation as well as by light and electron microscopy. Infection caused an influx of macrophages that were immunostained in cryostat sections by monoclonal antibody recognizing calprotectin.