Relationship of Salmonella Typhimurium 14028 strain and its dam and seqA mutants with gut microbiota dysbiosis in rats

<b>Introduction.</b> Disruptions in gut microbiota, known as dysbiosis, have been increasingly linked to pathogenic infections, with <i>Salmonella</i> Typhimurium being a notable contributor to these disturbances.<b>Hypothesis.</b> We hypothesize that the <i>S</i>. Typhimurium 14028 WT strain induces significant dysbiosis in the rat gut microbiota and that the <i>dam</i> and <i>seqA</i> genes play crucial roles in this process.<b>Aim</b>. In this study, it was aimed at investigating the dysbiotic activity of the <i>S</i>. Typhimurium 14028 WT strain on the rat gut microbiota and the roles of <i>dam</i> and <i>seqA</i> genes on this activity.<b>Method.</b> Changes in the rat gut microbiota were determined by examining the anal swap samples taken from the experimental groups of these animals using 16S rRNA high-throughput sequencing technology.<b>Results.</b> In the experimental groups, the dominant phyla were determined to be <i>Firmicutes</i> and <i>Bacteroidetes</i> (<i>P</i><0.05). However, while the rate of <i>Bacteroidetes</i> was significantly reduced in those treated with the WT and <i>seqA</i> mutants, no significant difference was observed in the <i>dam</i> mutant compared to the control group (<i>P</i><0.05). In all experimental animals, the dominant species was determined to be <i>Prevotella copri</i>, regardless of the experiment time and application. The analysis results of the samples taken on the third day from the rat groups infected with the <i>S.</i> Typhimurium 14028 WT strain (W2) presented the most striking data of this study.<b>Conclusion.</b> Through distance analysis, we demonstrated that a successful <i>Salmonella</i> infection completely changes the composition of the microbiota, dramatically reduces species diversity and richness in the microbiota and encourages the growth of opportunistic pathogens.