Phage Efficacy Assessment for Decolonizing Hyper-Virulent Klebsiella pneumoniae K1 ST23 in the Intestinal Microbiota : An In Vitro Study using the SHIME® Model.

Klebsiella pneumoniae is an opportunistic enterobacterium found in the nasopharyngeal and intestinal tracts, which has developed various antibiotic resistance mechanisms. In a hospital setting, the primary source of this pathogen is the intestinal microbiota, and early detection often proves challenging. Thus, preventive intestinal decolonization appears to be a viable solution to curb the spread and consequences of this pathogen, particularly using phages. In this context, this study aims to assess the effectiveness of phage vB_KpnP_K1-ULIP33 in decolonizing an intestinal microbiota colonized by a hyper-virulent ST23 K. pneumoniae with K1 capsule type (SA12), using the in vitro Simulator of Human Intestinal Microbial Ecosystem (SHIME). Although each replicate of the triplicate exhibited different implantations, no significant impact of phage and bacterial additions were observed on the microbiome in terms of short-chain fatty acid production, diversity parameters (α and β), and qPCR targeting different genera associated with chronic or acute bowel inflammation. However, the emergence of phage-resistant bacteria and potential biofilm formation prevent drawing definitive conclusions regarding the efficacy of phage ULIP33 alone as a decolonizer of SA12 in a simulated in vitro gastrointestinal model.
This research was funded by the Walloon Public Service, BIOWIN project: Inteliphages.