Campylobacter rectus mediates growth restriction in pregnant mice.

Background: Recent studies have suggested that subclinical infection may be an important cause of low birth weight. Campylobacters are important human pathogens, causing septicemia and occasionally abortion, premature labor, or severe perinatal infection. The potential role of oral species of Campylobacter in mediating adverse pregnancy outcomes in animal models has not yet been determined. Our objective was to determine the effects of Campylobacter rectus (C. rectus) infection on pregnancy outcomes in a mouse model.

Methods: On embryonic day (E) 7.5, pregnant mice received a subcutaneous, intra-chamber challenge with live C. rectus at concentrations of 0, 10(7) or 10(9) colony forming units (CFU)/ml. They were sacrificed on E 16.5 and fetuses were evaluated for stage of development, weight, and crown-rump length.

Results: Dams receiving C. rectus had more fetal resorptions after challenge with 10(7) or 10(9) CFU/ml (24.1% and 30.1%, respectively) than controls (9%). Higher numbers of growth-restricted fetuses were also observed in the C. rectus challenged groups (21%) as compared to controls (2.3%). Fetuses from dams challenged with 10(9) CFU/ml weighed less (0.49 +/- 0.05 g) and had shorter crown-rump lengths (14.69 +/- 0.56 mm) than controls (0.53 +/- 0.04 g; 15.54 +/- 0.63 mm). C. rectus was detected by polymerase chain reaction (PCR) in the placentas from both treated groups and in maternal liver tissues from the 10(9) CFU/ml challenged group.

Conclusions: Remote subcutaneous maternal C. rectus infection increases fetal resorptions and fetal growth restriction in a mouse model. The effects of an oral C. rectus infection on pregnancy remain to be determined.