Autoimmunity can potentially pre-dispose to, exacerbate or ameliorate pathogenic infections. The current study was designed to compare and understand the infection outcomes with Salmonella enterica serovar Typhimurium ATCC 14028s (S. Typhimurium) wild type (WT) and attenuated ΔrpoS strains, in autoimmune-prone lpr mice. C57BL/6 (B6) and B6/lpr (lpr) 6–8 weeks old mice were orally infected with S. Typhimurium WT and ΔrpoS strains. Disease outcomes were assessed with respect to survival, organ bacterial load, tissue damage and inflammation in infected mice. The acute infection stage (day 4) was examined and compared to the later stages (up to day 12) post ΔrpoS infection. S. Typhimurium WT exhibited an acute and lethal infection in both B6 and lpr mice. However, the ΔrpoS strain exhibited prolonged infection with reduced mortality in B6 mice but complete mortality in lpr mice. During late infection, bacterial load and serum IFNγ levels were higher in the ΔrpoS strain infected lpr mice compared to B6 mice. The ΔrpoS strain infected lpr mice also exhibited greater bacterial faecal shedding and greater tissue histopathological changes. Interestingly, ΔrpoS-infected B6 mice displayed minimal microbial load in the brain; however, sustained brain bacterial load was observed in ΔrpoS-infected lpr mice, corresponding to abnormal gait. Overall, S. Typhimurium ΔrpoS is competent in establishing infection but compromised in sustaining it. Nonetheless, lpr mice are less efficient in controlling this attenuated infection. The findings from the study demonstrate that genetic pre-disposition to autoimmunity is sufficient for greater host susceptibility to infection by attenuated S. Typhimurium strains.

自身免疫可能会诱发，加剧或改善病原性感染。目前研究的目的是比较和了解与感染结果肠沙门氏菌鼠伤寒沙门氏菌ATCC 14028s（小号。鼠伤寒沙门氏菌）的野生型（WT）和减毒Δ的rpoS菌株，自身免疫倾向的lpr小鼠。C57BL / 6（B6）和B6 / LPR（LPR）6-8周龄小鼠口服感染S.鼠伤寒沙门氏菌野生型和Δ的rpoS菌株。就存活，器官细菌负荷，组织损伤和感染小鼠的炎症评估了疾病结局。检查急性感染阶段（第4天）并将其与Δ后的后期阶段（直至第12天）进行比较rpoS感染。小号。鼠伤寒WT在B6和lpr小鼠中均表现出急性和致死性感染。但是，ΔrpoS菌株在B6小鼠中表现出长期感染，死亡率降低，但在lpr小鼠中完全死亡。在晚期感染期间，与r6 S小鼠相比，ΔrpoS株感染的lpr小鼠的细菌载量和血清IFNγ水平更高。被ΔrpoS株感染的lpr小鼠还表现出更大的细菌排泄和更大的组织病理学变化。有趣的是，ΔrpoS感染的B6小鼠大脑中的微生物负荷最小；然而，在ΔrpoS感染的lpr小鼠中观察到持续的脑细菌负荷，这与步态异常有关。总体而言，S。鼠伤寒ΔrpoS能胜任感染，但在维持感染方面却受到损害。但是，lpr小鼠在控制这种减毒感染中效率较低。该研究的结果表明，对自身免疫的遗传易感性足以使宿主对减毒S感染的敏感性更高。鼠伤寒菌株。