The Salmonella Pathogenicity Island 2 regulator ssrA promotes reproductive tract but not intestinal colonization in chickens.
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.
Bohez
Lotte
L
Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium. Lotte.Bohez@UGent.be
Gantois
Inne
I
Ducatelle
Richard
R
Pasmans
Frank
F
Dewulf
Jeroen
J
Haesebrouck
Freddy
F
Van Immerseel
Filip
F
D000375:Aging; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics*; D002353:Carrier State / Q000382:microbiology; D002460:Cell Line; D002645:Chickens; D005260:Female; D017353:Gene Deletion; D006801:Humans; D007422:Intestines / Q000166:cytology* / Q000382:microbiology; D008264:Macrophages; D008297:Male; D008565:Membrane Proteins / Q000235:genetics*; D010053:Ovary / Q000382:microbiology; D010057:Oviducts / Q000382:microbiology; D010058:Oviposition; D011201:Poultry Diseases / Q000382:microbiology*; D012329:RNA, Bacterial / Q000378:metabolism*; D012477:Salmonella enteritidis / Q000235:genetics*; D013047:Specific Pathogen-Free Organisms
D001426:Bacterial Proteins; D008565:Membrane Proteins; D012329:RNA, Bacterial; C440638:SPI-2 protein, Salmonella; C096222:tmRNA