title: Salmonella enterica subspecies enterica serovar Enteritidis Salmonella pathogenicity island 2 type III secretion system: role in intestinal colonization of chickens and systemic spread.
abstract: Salmonella enterica subspecies enterica serovar Enteritidis (S. Enteritidis) has been identified as a significant cause of salmonellosis in humans. Salmonella pathogenicity islands 1 and 2 (SPI-1 and SPI-2) each encode a specialized type III secretion system (T3SS) that enables Salmonella to manipulate host cells at various stages of the invasion/infection process. For the purposes of our studies we used a chicken isolate of S. Enteritidis (Sal18). In one study, we orally co-challenged 35-day-old specific pathogen-free (SPF) chickens with two bacterial strains per group. The control group received two versions of the wild-type strain Sal18: Sal18 attTn7 : : tet and Sal18 attTn7 : : cat, while the other two groups received the wild-type strain (Sal18 attTn7 : : tet) and one of two mutant strains. From this study, we concluded that S. Enteritidis strains deficient in the SPI-1 and SPI-2 systems were outcompeted by the wild-type strain. In a second study, groups of SPF chickens were challenged at 1 week of age with four different strains: the wild-type strain, and three other strains lacking either one or both of the SPI-1 and SPI-2 regions. On days 1 and 2 post-challenge, we observed a reduced systemic spread of the SPI-2 mutants, but by day 3, the systemic distribution levels of the mutants matched that of the wild-type strain. Based on these two studies, we conclude that the S. Enteritidis SPI-2 T3SS facilitates invasion and systemic spread in chickens, although alternative mechanisms for these processes appear to exist.
authors.affiliation: Vaccine and Infectious Disease Organization, University of Saskatchewan, 120 Veterinary Road, Saskatoon, SK, Canada S7N 5E3.
authors.forename: Amanda L S
authors.initials: ALS
authors.lastname: Wisner
authors.affiliation: Vaccine and Infectious Disease Organization, University of Saskatchewan, 120 Veterinary Road, Saskatoon, SK, Canada S7N 5E3.
authors.forename: Taseen S
authors.initials: TS
authors.lastname: Desin
authors.affiliation: Vaccine and Infectious Disease Organization, University of Saskatchewan, 120 Veterinary Road, Saskatoon, SK, Canada S7N 5E3.
authors.forename: Birgit
authors.initials: B
authors.lastname: Koch
authors.affiliation: Vaccine and Infectious Disease Organization, University of Saskatchewan, 120 Veterinary Road, Saskatoon, SK, Canada S7N 5E3.
authors.forename: Po-King S
authors.initials: PS
authors.lastname: Lam
authors.affiliation: Vaccine and Infectious Disease Organization, University of Saskatchewan, 120 Veterinary Road, Saskatoon, SK, Canada S7N 5E3.
authors.forename: Emil M
authors.initials: EM
authors.lastname: Berberov
authors.affiliation: Vaccine and Infectious Disease Organization, University of Saskatchewan, 120 Veterinary Road, Saskatoon, SK, Canada S7N 5E3.
authors.forename: Claudia S
authors.initials: CS
authors.lastname: Mickael
authors.affiliation: Vaccine and Infectious Disease Organization, University of Saskatchewan, 120 Veterinary Road, Saskatoon, SK, Canada S7N 5E3.
authors.forename: Andrew A
authors.initials: AA
authors.lastname: Potter
authors.affiliation: Vaccine and Infectious Disease Organization, University of Saskatchewan, 120 Veterinary Road, Saskatoon, SK, Canada S7N 5E3.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Köster
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002645:Chickens / Q000382:microbiology; D044404:Genomic Islands; D006801:Humans; D007422:Intestines / Q000382:microbiology*; D011201:Poultry Diseases / Q000382:microbiology*; D012481:Salmonella Infections, Animal / Q000382:microbiology*; D012477:Salmonella enteritidis / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity*; D013047:Specific Pathogen-Free Organisms; D014774:Virulence
chemical_list: D001426:Bacterial Proteins