Management of Isolated Fever in Labour Compared with Clinical Chorioamnionitis in a Quaternary Centre.

OBJECTIVES: To investigate treatment patterns of women with isolated fever in labour and evaluate if variables in the sepsis in obstetrics score (SOS) or fetal tachycardia are associated with treatment differences. Our secondary objective was to compare women with isolated fever in labour with women with clinical chorioamnionitis to identify any clinicodemographic differences. METHODS: A retrospective cohort study of 473 patients at BC Women's Hospital who presented with isolated fever in labour between January 2011 and April 2016 compared with a dataset of 1135 women with clinical chorioamnionitis from 2011 to 2016 in the same institution. RESULTS: In our cohort of isolated fever in labour, antibiotics were given 74.2 % of the time, and the majority received cefazolin and metronidazole (80.9%, of those who received antibiotics). Higher maternal temperature and heart rate at time of first fever and fetal tachycardia were associated with more antibiotic use. Slightly higher maternal temperature was associated with use of a saline bolus and blood cultures. The proportion of women with a SOS greater than 5 increased 4.5-fold from time of first fever to time of maximum SOS. There were fewer cesarean deliveries in the isolated fever in labour group compared with the clinical chorioamnionitis group (22.4% vs. 54.0%; P < 0.0001). CONCLUSIONS: Slightly higher maternal temperature was associated with increased treatment, including antibiotic use, saline bolus administration, and blood cultures. As evidenced by the higher proportion of women with an SOS over 5, women with isolated fever in labour may have a propensity to deteriorate clinically.

Complement C3 Drives Autophagy-Dependent Restriction of Cyto-invasive Bacteria.

In physiological settings, the complement protein C3 is deposited on all bacteria, including invasive pathogens. However, because experimental host-bacteria systems typically use decomplemented serum to avoid the lytic action of complement, the impact of C3 coating on epithelial cell responses to invasive bacteria remains unexplored. Here, we demonstrate that following invasion, intracellular C3-positive Listeria monocytogenes is targeted by autophagy through a direct C3/ATG16L1 interaction, resulting in autophagy-dependent bacterial growth restriction. In contrast, Shigella flexneri and Salmonella Typhimurium escape autophagy-mediated growth restriction in part through the action of bacterial outer membrane proteases that cleave bound C3. Upon oral infection with Listeria, C3-deficient mice displayed defective clearance at the intestinal mucosa. Together, these results demonstrate an intracellular role of complement in triggering antibacterial autophagy and immunity against intracellular pathogens. Since C3 indiscriminately associates with foreign surfaces, the C3-ATG16L1 interaction may provide a universal mechanism of xenophagy initiation.