Departamento de Clinica e Cirurgia Veterinária, Escola de Veterinária da Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, Belo Horizonte, MG, Brazil.
Vet Pathol. 2011 Sep;48(5):933-41. doi: 10.1177/0300985810386468. Epub 2010 Nov 1.
The goal of this study was to morphologically characterize a ligated ileal loop model of Salmonella enterica serotype Typhimurium infection in rhesus macaques (Macaca mulatta) and to verify the occurrence of Salmonella-induced cell death in vivo. Eight adult healthy male rhesus macaques were used for ligated ileal loop surgery. Four macaques had been intravenously inoculated with simian immunodeficiency virus (SIV) mac251. Ileal ligated loops were inoculated with wild-type (WT) S. Typhimurium strain IR715 (ATCC14028 nal (r)), an isogenic noninvasive mutant strain (ATCC14028 nal (r) ΔsipAΔsopABDE2), or sterile Luria Bertani broth. Loops were surgically removed at 2, 5, and 8 hours post-inoculation (hpi). Intestinal samples were processed for histopathology, immunohistochemistry for detecting Salmonella, terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL), and transmission electron microscopy. Combined histopathology scores were similar between SIV-infected and control macaques. As expected, the invasion-deficient mutant was less pathogenic than WT S. Typhimurium. Neutrophil infiltrate in the intestinal mucosa correlated with bacterial loads (r = 0.7148; P < .0001) and fluid accumulation (r = 0.6019; P < .0001) in the lumen of the intestinal loops. Immunolabeled WT S. Typhimurium was observed in the epithelium and lamina propria at the tip of the villi at 2 hpi, progressing toward deeper lamina propria at 5-8 hpi. Most TUNEL-positive cells localized to the lamina propria, and some had morphological features of macrophages. Ultrastructurally, bacteria were observed intracellularly in the lamina propria as well as within apoptotic bodies. This study provides morphological evidence of Salmonella-induced cell death in vivo in a relevant nonhuman primate model.
本研究的目的是对志贺氏鼠伤寒沙门氏菌感染结扎回肠模型进行形态学特征描述，并验证体内沙门氏菌诱导的细胞死亡是否发生。8 只成年雄性恒河猴（Macaca mulatta）用于回肠结扎手术。4 只猴子已静脉接种猴免疫缺陷病毒（SIV）mac251。将野生型（WT）鼠伤寒沙门氏菌菌株 IR715（ATCC14028 nal（r））、同源非侵袭性突变株（ATCC14028 nal（r）ΔsipAΔsopABDE2）或无菌 Luria Bertani 肉汤接种到结扎的回肠环中。在接种后 2、5 和 8 小时（hpi）通过手术取出回肠环。对肠组织样本进行组织病理学检查、免疫组织化学检测沙门氏菌、末端脱氧核苷酸转移酶介导的 dUTP-生物素缺口末端标记（TUNEL）和透射电子显微镜检查。SIV 感染和对照猴子的联合组织病理学评分相似。不出所料，侵袭缺陷突变株的致病性低于 WT 鼠伤寒沙门氏菌。肠黏膜中的中性粒细胞浸润与细菌负荷（r = 0.7148；P <.0001）和肠环腔中的液体积累（r = 0.6019；P <.0001）相关。在 2 hpi 时，在绒毛顶端的上皮和固有层中观察到免疫标记的 WT 鼠伤寒沙门氏菌，在 5-8 hpi 时向更深的固有层进展。大多数 TUNEL 阳性细胞定位于固有层，一些具有巨噬细胞的形态特征。超微结构观察到细菌在固有层和凋亡小体中均为细胞内。本研究为相关非人类灵长类动物模型中体内沙门氏菌诱导的细胞死亡提供了形态学证据。
