Project description:Preterm birth is currently the leading cause of neonatal morbidity and mortality. Genetic, immunological and infectious causes are suspected. Preterm infants have a higher risk of severe bacterial neonatal infections, most of which are caused by Escherichia coli an in particular E. coli K1strains. Women with history of preterm delivery have a high risk of recurrence and therefore constitute a target population for the development of vaccine against E. coli neonatal infections. Here, we characterized the immunological, microbiological and protective properties of a live attenuated vaccine candidate in adult female mice and their pups against after a challenge by K1 and non-K1 strains of E. coli. Our results show that the E. coli K1 E11 aroA vaccine induces strong immunity, driven by polyclonal bactericidal antibodies. In our model of meningitis, pups born to mothers immunized before mating were well protected against various K1 and non-K1 strains of E. coli. Given the very high mortality rate and the neurological sequalae associated with neonatal E. coli K1 meningitis, our results constitute preclinical proof of concept for the development of a live attenuated vaccine against severe E. coli infections in women at risk of preterm delivery.
Project description:Transcript abundance in Escherichia coli O157:H7 was determined in the presence or absence of pulsed expression of the small RNA, AsxR. AsxR was cloned under the control the arabinose inducible promoter Para. Escherichia coli O157:H7 str. TUV93-0 with pAsxR or empty vector was cultured in MEM-HEPES media to an OD600 of 0.8 and 0.2% arabinose added. 10min after addition of arabinose 10ml of cells were harvested and and pellets resuspended in 1ml of Trizol and total RNA isolated. RNAs were labelled using the SuperScript Plus indirect cDNA labelling System. Triplicate control RNAs were pooled and hybridised to seperate AsxR test RNAs on three microarays. Arrays were hybridised using the Maui hybridisation platform and Scann using and Axon Autoloader Scanner. GenePix software was used to analyse images and GPR files were analysed using Genespring 7.3.1.
