title: Invasion of Caco-2 cells by Salmonella typhimurium (Copenhagen) isolates from healthy and sick chickens.
abstract: In a previous study, Salmonella isolates of sick birds were distinguished from those of apparently healthy birds by their high degree of invasion of tissue culture cells. In this study, a single pair of Salmonella isolates was examined to determine the source of this observed difference in invasion. When isolates were allowed to invade Caco-2 cells for 8 hours, the isolate from the sick bird (S) appeared to invade in greater numbers than did the isolate from the healthy bird (H). However, when invasion was distinguished from intracellular growth/survival, it was found that H invaded in greater numbers than S, but once inside the cell, H declined in number, and S increased. Inhibition of RNA, protein, and DNA syntheses lessened the degree to which both invaded. The presence of mannose inhibited invasion by S but did not appear to inhibit invasion by H. Trypsin treatment of monolayers affected invasion of S and H, whereas neuraminidase treatment did not. There was no significant difference noted between S and H in ability to adhere to fixed monolayers. Therefore, the two isolates tested differ in their mechanisms of entry into Caco-2 cells, the efficiency with which they invade, and their ability to survive within Caco-2 cells.
authors.affiliation: Department of Veterinary and Microbiological Sciences, North Dakota State University, Fargo 58105, USA.
authors.forename: T J
authors.initials: TJ
authors.lastname: Kottom
authors.forename: L K
authors.initials: LK
authors.lastname: Nolan
authors.forename: J
authors.initials: J
authors.lastname: Brown
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion; D018938:Caco-2 Cells; D002460:Cell Line; D002645:Chickens / Q000382:microbiology*; D004926:Escherichia coli / Q000502:physiology; D006801:Humans; D008070:Lipopolysaccharides / Q000096:biosynthesis / Q000302:isolation & purification; D011201:Poultry Diseases; D012016:Reference Values; D012481:Salmonella Infections, Animal / Q000382:microbiology*; D012486:Salmonella typhimurium / Q000302:isolation & purification / Q000472:pathogenicity / Q000502:physiology*; D014774:Virulence
chemical_list: D008070:Lipopolysaccharides