INTRAPERITONEAL ADMINISTRATION OF SHIGA TOXIN TYPE 2 IN RATS IN THE LATE STAGE OF PREGNANCY PRODUCES PREMATURE DELIVERY OF DEAD FETUSES

BURDET JULIANA; ZOTTA ELSA; FRANCHI ANA M; IBARRA CRISTINA

PLACENTA

Elsevier

Año: 2009 vol. 30 p. 491 - 496

0143-4004

Infection associated with Shiga toxin-producing Escherichia coli (STEC) andsubsequent Hemolytic-Uremic Syndrome (HUS) have become relevant inpublic health since STEC is considered as one of the most importantemergent pathogens. STEC infection may either be asymptomatic or beginwith watery diarrhea associated with hemorrhagic colitis and HUS. The majorvirulence factor of STEC is Shiga toxin type 1 or 2 (Stx1, Stx2) althoughstrains that express only Stx2 are highly prevalent. Up to now, it has not beenestablished whether STEC infection affect pregnant women. In this study, weevaluated the effect of Stx2 on maternal lethality, fetal status and delivery timeby injecting Stx2 in rats in the late stage of pregnancy. Stx2 induced fetalresorption, placental abruption, intrauterine hemorrhage and fetal death at 1-2days post-injection in a dose-dependent manner. With 2 ng Stx2/g bodyweight, placentas and fetuses presented extensive necrotic areas, while uteriand kidneys showed normal histology. Immunolocalization of Stx2 wasobserved in placentas and fetuses. With 4 and 6 ng Stx2/g body weightmaternal death was also observed. Those rats that survived after Stx2-treatment were able to become pregnant and deliver normal pups at term.Our results show, for the first time, that the preterm labor with fetal deathobserved in treated rats may be a consequence of the action of Stx2 on thefeto-maternal unit. Although there are no reports of Stx2 effects in humanpregnancy, we speculate that STEC infections could be one of the causes notyet determined of fetal morbimortality.