The Response of Murine Gut Microbiome in the Presence of Altered rpoS Gene of Klebsiella pneumoniae

The murine model is invaluable for studying intricate interactions among gut microbes; hosts; and diseases. However; the impact of genetic variations in the murine microbiome; especially in disease contexts such as <i>Klebsiella pneumoniae</i> (<i>Kp</i>) infection; still needs to be explored. <i>Kp</i>; an opportunistic global pathogen; is becoming increasingly prevalent in regions like Asia; especially China. This study explored the role of the gut microbiota during <i>Kp</i> infection using mouse model; including wild-type and <i>rpoS</i> mutants of Kp138; KpC4; and KpE4 from human; maize; and ditch water; respectively. Under stress conditions; RpoS reconfigures global gene expression in bacteria; shifting the cells from active growth to survival mode. Our study examined notable differences in microbiome composition; finding that <i>Lactobacillus</i> and <i>Klebsiella</i> (particularly in WKp138) were the most abundant genera in mice guts at the genus level in all wild-type treated mice. In contrast; <i>Firmicutes</i> were predominant in the healthy control mice. Furthermore; <i>Clostridium</i> was the dominant genus in all mutants; mainly in ∆KpC4; and was absent in wild-type treated mice. Differential abundance analysis identified that these candidate taxa potentially influence disease progression and pathogen virulence. Functional prediction analysis showed that most bacterial groups were functionally involved in biosynthesis; precursor metabolites; degradation; energy generation; and metabolic cluster formation. These findings challenge the conventional understanding and highlight the need for nuanced interpretations in murine studies. Additionally; this study sheds light on microbiome-immune interactions in <i>K. pneumoniae</i> infection and proposes new potential therapeutic strategies.