Phage targeting neonatal meningitis E. coli K1 in the intestinal microbiota of pregnant donors and impact on bacterial populations

Introduction: Escherichia coli K1 is a leading cause of neonatal meningitis. The symptomatic carriage of these strains in the maternal intestinal microbiota constitutes a risk of vertical transmission to infant at birth. This work aimed to evaluate the efficacy of phage therapy against E. coli K1 in an intestinal environment and its impact on the intestinal microbiota. Materials & Methods: Three independent experiments were conducted on the SHIME® system, the first one with only the phage vB_EcoP_K1_ULINTec4, the second experiment, with only E. coli K1 and the last experiment, with both E. coli K1 and phage. Microbiota was monitored using metagenetic analysis, qPCR, SCFA analysis and the induction of aryl hydrocarbon receptor (AhR).
Results: K1_ULINTec4, inoculated alone, was progressively cleared by the system but replicates in presence of its host. E. coli K1 persisted in the microbiota but decreases in presence of the phage. The impact on the microbiota was found to be donor dependent and bacterial populations were not dramatically affected by K1_ULINTec4 alone or in the presence of its host.
Conclusion: In conclusion, those experiments showed that the phage was able to infect the E. coli K1 in the system but did not completely eliminate the bacterial load.
This research was financially supported by Wallonia in the framework of the call for projects organised by BioWin competitiveness cluster.