Establishment of a mandible defect model in rabbits infected with multiple bacteria and bioinformatics analysis

Objective: A model of infectious mandibular defect (IMD) caused by infection with Staphylococcus aureus and Pseudomonas aeruginosa was established to explore the occurrence and development of IMD and identify key genes by transcriptome sequencing and bioinformatics analysis. Methods: S. aureus and P. aeruginosa were diluted to 3×108 CFU/ml, and 6×3×3 mm defects lateral to the Mandibular Symphysis were induced in 28 New Zealand rabbits. Sodium Morrhuate (0.5%) and 50 μL bacterial solution were injected in turn; the effects were evaluated through postoperative observations, imaging and histological analyses. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, and protein‒protein interaction (PPI) network analyses were performed to investigate the function of the differentially expressed genes (DEGs). Results: Bioinformatics analysis showed a total of 1,804 DEGs, of which 743 were upregulated and 1061 were downregulated. GO and KEGG analyses showed that the DEGs were enriched in immunity and osteogenesis inhibition, and the core genes identified by the PPI network were enriched in the Hedgehog pathway, which plays a role in inflammation and tissue repair; the MEF2 transcription factor family was predicted by IRegulonConclusion: By direct injection of bacterial solution into the rabbit mandible defect area, the rabbit IMD model was successfully established. Bioinformatics analysis results showed that the Hedgehog pathway is potential therapeutic targets for IMD. Three bone tissue samples from the infectious bone defect group, and four bone tissue samples were collected from the healthy control group