Host Tropism and Its Implications for Murine Infection Models.

() is a pathobiont of humans as well as a multitude of animal species. The high prevalence of multi-resistant and more virulent strains of necessitates the development of new prevention and treatment strategies for infection. Major advances towards understanding the pathogenesis of diseases have been made using conventional mouse models, i.e., by infecting naïve laboratory mice with human-adapted strains. However, the failure to transfer certain results obtained in these murine systems to humans highlights the limitations of such models. Indeed, numerous vaccine candidates showed promising results in conventional mouse models but failed to offer protection in human clinical trials. These limitations arise not only from the widely discussed physiological differences between mice and humans, but also from the lack of attention that is paid to the specific interactions of with its respective host. For instance, animal-derived lineages show a high degree of host tropism and carry a repertoire of host-specific virulence and immune evasion factors. Mouse-adapted strains, humanized mice, and microbiome-optimized mice are promising approaches to overcome these limitations and could improve transferability of animal experiments to human trials in the future.