A temporary cholesterol-rich diet and bacterial extracellular matrix factors favor Salmonella spp. biofilm formation in the cecum

Asymptomatic chronic carriers occur in approximately 5% of humans infected with Salmonella enterica serovar Typhi (S. Typhi) and represent a critical reservoir for bacterial dissemination. While chronic carriage primarily occurs in the gallbladder through biofilms on gallstones, additional anatomic sites have been suggested that could also harbor Salmonella. S. Typhimurium, orally-infected 129X1/SvJ mice were pre-treated with a cholesterol-rich diet as a gallstone model for chronic carriage. We observed S. Typhimurium in feces and the cecum during early and persistent infection. Furthermore, bacterial biofilm-like aggregates were associated with the cecum epithelium at 7- and 21-day post-infection (DPI) in mice on a lithogenic diet (Ld) and correlated with an increase in cecal cholesterol at 21 DPI. Salmonella’s extracellular matrix (ECM) was demonstrated as important in colonizing the cecum, as survival and aggregate formation significantly decreased when mice were infected with a quad..., Ethics statement. The mice used in this study were housed in strict adherence to the guidelines established by the Abigail Wexner Research Institute (AWRI) Institutional Animal Care and Use Committee (IACUC). All experimental procedures involving mice were conducted with the appropriate authorization obtained through AWRI IACUC protocol AR18-00080, which complied with the statutory requirements outlined in the Guide for the Care and Use of Laboratory Animals.
Bacterial Strains. Previously, we described the constructions of Salmonella mutant strains deficient in biofilm formation capacity (35). The following bacterial strains were utilized in this study: S. Tm 14028 (S. Tmwt; JSG210), S. Tm curli mutant (S. TmΔcsgA; JSG3540), S. Tm colanic acid mutant (S. TmΔwcaM; JSG3712), S. Tm O antigen capsule mutant (S. TmΔyihO; JSG3672), S. Tm cellulose mutant (S. TmΔbcsE; JSG3838), the doble ECM mutant (S. TmΔcsAΔbcsE: JSG3977), S. Tm quadruple ECM mutant ΔwcaM, ΔcsgA, ΔyihO, ΔbcsE (S. Tm ECM..., , # A temporary cholesterol-rich diet and bacterial extracellular matrix factors favor *Salmonella* spp. biofilm formation in the cecum

[https://doi.org/10.5061/dryad.1zcrjdg2p](https://doi.org/10.5061/dryad.1zcrjdg2p)

## Description of the data and file structure

We investigated the adaptive survival and biofilm formation of *Salmonella* in the gastrointestinal tract of immunocompetent mice that had been pre-fed a lithogenic diet. To track bacterial presence across various tissues, we utilized CFU assays, flow cytometry, histopathology analysis, ex vivo cholesterol quantification, and immunohistochemistry/immunofluorescence.

### Files and variables

#### File: Fig_1.xlsx

**Description:**  This figure shows a schematic representation of the experimental strategy. 129X1/SvJ mice were pre-treated with either a lithogenic (Ld) or a normal diet (Nd) for 6 weeks and infected by the intragastric route with 1x107 CFUs of *S*. Tm*wt*. The severity level is denoted with black arrows, a score ...,

约5%感染肠炎沙门氏菌伤寒血清型（*Salmonella enterica serovar Typhi*, S. Typhi）的人类会成为无症状慢性携带者，这类携带者是细菌传播的关键储存宿主。慢性携带状态主要通过胆囊内胆结石表面的生物膜形成，但也有研究提示其他解剖部位也可能定植沙门氏菌。本研究使用经口感染的129X1/SvJ小鼠，以高胆固醇饮食构建胆结石慢性携带模型。我们观察到，在感染早期和持续感染阶段，小鼠粪便与盲肠中均可检出鼠伤寒沙门氏菌（*Salmonella Typhimurium*, S. Tm）。进一步研究发现，在致石饮食（lithogenic diet, Ld）组小鼠中，感染后7天和21天（感染后天数，days post-infection, DPI），盲肠上皮细胞可形成类似细菌生物膜的聚集体，且该聚集体与感染后21天盲肠胆固醇水平升高呈正相关。研究证实沙门氏菌的细胞外基质（extracellular matrix, ECM）在盲肠定植过程中发挥重要作用：当小鼠感染四重缺失突变株时，细菌存活率与聚集体形成能力均显著下降……

### 伦理声明
本研究中使用的小鼠饲养严格遵循阿比盖尔·韦克斯纳研究所（Abigail Wexner Research Institute, AWRI）机构动物护理与使用委员会（Institutional Animal Care and Use Committee, IACUC）制定的指南。所有涉及小鼠的实验操作均通过AWRI IACUC协议AR18-00080获得相应授权，且符合《实验动物护理与使用指南》中规定的法定要求。

### 细菌菌株
此前我们已报道了生物膜形成能力缺陷的沙门氏菌突变株的构建方法（文献35）。本研究使用的菌株如下：鼠伤寒沙门氏菌14028野生株（S. Tm^wt^; JSG210）、鼠伤寒沙门氏菌菌毛突变株（S. TmΔcsgA; JSG3540）、鼠伤寒沙门氏菌海藻酸突变株（S. TmΔwcaM; JSG3712）、鼠伤寒沙门氏菌O抗原荚膜突变株（S. TmΔyihO; JSG3672）、鼠伤寒沙门氏菌纤维素突变株（S. TmΔbcsE; JSG3838）、双缺失细胞外基质突变株（S. TmΔcsAΔbcsE; JSG3977）、鼠伤寒沙门氏菌四重细胞外基质突变株ΔwcaM、ΔcsgA、ΔyihO、ΔbcsE（S. Tm ECM……）

# 短期高胆固醇饮食与细菌细胞外基质因子促进沙门氏菌属在盲肠的生物膜形成
https://doi.org/10.5061/dryad.1zcrjdg2p

## 数据与文件结构说明
本研究探讨了预饲致石饮食的免疫健全小鼠胃肠道内沙门氏菌的适应性存活与生物膜形成情况。为追踪细菌在各组织中的定植情况，我们采用了菌落形成单位（Colony-Forming Unit, CFU）计数法、流式细胞术、组织病理学分析、离体胆固醇定量检测以及免疫组织化学/免疫荧光技术。

### 文件与变量
#### 文件：Fig_1.xlsx
**描述：** 本文件展示了实验策略的示意图。将129X1/SvJ小鼠预饲致石饮食（Ld）或正常饮食（Nd）6周后，经胃内接种1×10^7 CFU的鼠伤寒沙门氏菌野生株。实验的严重程度以黑色箭头标注，评分……