Bohez Lotte, Gantois Inne, Ducatelle Richard, Pasmans Frank, Dewulf Jeroen, Haesebrouck Freddy, Van Immerseel Filip
Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium.
Vet Microbiol. 2008 Jan 1;126(1-3):216-24. doi: 10.1016/j.vetmic.2007.06.025. Epub 2007 Jun 30.
Using a deletion mutant in the regulator of SPI-2, ssrA, we investigated the role of SPI-2 in invasion, intestinal colonization and reproductive tract infection of chickens by Salmonella Enteritidis. The ssrA mutant was fully invasive in phagocytic and non-phagocytic cells but failed to persist within chicken macrophages. The ability of Salmonella Enteritidis to cause disease in orally infected 1-day-old chicks was not altered when ssrA was deleted. Furthermore, caecal colonization was not affected, while spleen and liver showed reduced colonization. Following intra-peritoneal and intravenous infection of 1-day-old chicks, internal organ colonization was strongly reduced. After intravenous inoculation in adult laying hens bacterial numbers of the ssrA mutant were significantly lower in oviducts and ovaries as compared to the wild type strain. The chickens showed less reproductive tract lesions and the recovery of egg production were faster compared to the wild type strain infected chickens. These findings indicate that the SPI-2 regulator ssrA promotes reproductive tract colonization, but is not essential for intestinal colonization of chickens with the host non-specific serotype Enteritidis.
利用SPI-2调节因子ssrA的缺失突变体，我们研究了SPI-2在肠炎沙门氏菌对鸡的侵袭、肠道定植和生殖道感染中的作用。ssrA突变体在吞噬细胞和非吞噬细胞中具有完全侵袭性，但无法在鸡巨噬细胞内存活。当缺失ssrA时，肠炎沙门氏菌在经口感染的1日龄雏鸡中致病的能力并未改变。此外，盲肠定植未受影响，而脾脏和肝脏的定植减少。在对1日龄雏鸡进行腹腔和静脉感染后，内脏器官的定植大幅减少。在成年产蛋母鸡中进行静脉接种后，与野生型菌株相比，ssrA突变体在输卵管和卵巢中的细菌数量显著降低。与感染野生型菌株的鸡相比，这些鸡的生殖道病变较少，产蛋恢复也更快。这些发现表明，SPI-2调节因子ssrA促进生殖道定植，但对于肠炎沙门氏菌这种宿主非特异性血清型在鸡肠道中的定植并非必需。
