Abstract
Raoultella ornithinolytica is an Enterobacteriaceae bacterium that can infect both humans and animals, while luteolin-7-O-glucoside (IOG) is a flavonoid that has broad effects on the intestinal microbiota of healthy animals. However, current studies lack sufficient data on intestinal microbiota dysbiosis and drug resistance transmission caused by R. ornithinolytica and the possible role of IOG. In this study, BALB/c mice were infected with R. ornithinolytica carrying bla(NDM-1) gene and treated with IOG (3 mg/kg·d and 6 mg/kg·d) to analyze the diversity of intestinal microbiota and the transfer of bla(NDM-1) between bacteria. The findings indicated that R. ornithinolytica B1645-1 exhibited a significant ability to enhance the Firmicutes/Bacteroidota ratio and increase the relative abundance of Lactobacillus and Bacillus after 48 h, where as 6 mg/kg·d IOG had an opposite effect. Moreover, R. ornithinolytica B1645-1 facilitated the emergence of drug-resistant bacteria and promoted bla(NDM-1) gene transfer in Enterococcus, Escherichia, Klebsiella, Acinetobacter, Bacillus, Brevibacterium, and Lactobacillus. Enterococcus was the predominant genus at 48 h. Surprisingly, 6 mg/kg·d IOG significantly inhibited the production of drug-resistant bacteria and promoted bla(NDM-1) gene transfer from Enterococcus to Lactobacillus at 144 h. However, the role of Lactobacillus as a recipient for drug-resistant genes should be of more concern.