부산대학교 도서관

OBJECTIVE:: The mechanism of infection-related deaths of pregnant rats and intrauterine growth restriction are not understood. We assessed whether nitric oxide (NO) has differential effects on infection with Escherichia coli Dr/Afa mutants that lack either AfaE or AfaD invasins. STUDY DESIGN:: Sprague-Dawley rats were infected intrauterinally with the clinical strain of E coli AfaED or 1 of its isogenic mutants in the presence or absence of the NO synthesis inhibitor N-nitro-L-arginine methyl ester (L-NAME). Maternal/fetal mortality rates, fetoplacental weight, and infection rates were evaluated. RESULTS:: Maternal and/or fetal death was associated with the presence of at least 1 virulence factor (AfaED>AfaED>AfaED) and was increased by L-NAME treatment. The fetal and placental weights were lower than controls and were further reduced by L-NAME treatment. CONCLUSION:: These results demonstrate that NO enhanced AfaE- and AfaD-mediated virulence and plays an important role in Dr/Afa E coli gestational tropism.