Vi-deficient and nonfimbriated mutants of Salmonella typhi agglutinate human blood type antigens and are hyperinvasive.
We generated nonfimbriated mutants from both Vi-positive and -negative Salmonella typhi to analyze the role of type 1 fimbriae and Vi-antigen in bacterial invasion. A Vi-defective mutant of S. typhi GIFU 10007-3 was more invasive than the wild-type strain GIFU 10007. The wild-type strain expressing Vi-antigen did not agglutinate both Saccharomyces cerevisiae and human erythrocytes but Vi-defective mutants were able to agglutinate S. cerevisiae and human erythrocytes. Nonfimbriated mutants from Vi-negative GIFU 10007-3 lost the ability to adhere to S. cerevisiae but still could agglutinate human erythrocytes. The Vi-negative mutant increased secreted proteins and became 5-fold more invasive than the wild-type strain. Nonfimbriated Vi mutants became 50-120-fold more invasive than the wild-type GIFU 10007. To determine why nonfimbriated Vi mutants still agglutinate human red blood cells, we searched bacterial proteins that could bind human blood-type antigens. We finally identified a candidate 37 kDa outer membrane protein that recognized fucosyl-galactose, a structure common to blood type A, B and H antigens.
Miyake
M
M
Department of Microbiology, School of Pharmaceutical Sciences, University of Shizuoka, Japan.
Zhao
L
L
Ezaki
T
T
Hirose
K
K
Khan
A Q
AQ
Kawamura
Y
Y
Shima
R
R
Kamijo
M
M
Masuzawa
T
T
Yanagihara
Y
Y
D000017:ABO Blood-Group System / Q000276:immunology*; D000371:Agglutination; D000942:Antigens, Bacterial / Q000502:physiology*; D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism; D010861:Fimbriae, Bacterial / Q000502:physiology*; D006801:Humans; D009154:Mutation; D011135:Polysaccharides, Bacterial / Q000502:physiology*; D012485:Salmonella typhi / Q000502:physiology*
D000017:ABO Blood-Group System; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D011135:Polysaccharides, Bacterial