Escherichia coli O123 O antigen genes and polysaccharide structure are conserved in some Salmonella enterica serogroups.
The serotyping of O and H antigens is an important first step in the characterization of Salmonella enterica. However, serotyping has become increasingly technically demanding and expensive to perform. We have therefore sequenced additional S. enterica O antigen gene clusters to provide information for the development of DNA-based serotyping methods. Three S. enterica isolates had O antigen gene clusters with homology to the Escherichia coli O123 O antigen region. O antigen clusters from two serogroup O58 S. enterica strains had approximately 85 % identity with the E. coli O123 O antigen region over their entire length, suggesting that these Salmonella and E. coli O antigen regions evolved from a common ancestor. The O antigen cluster of a Salmonella serogroup O41 isolate had a lower level of identity with E. coli O123 over only part of its O antigen DNA cluster sequence, suggesting a different and more complex evolution of this gene cluster than those in the O58 strains. A large part of the Salmonella O41 O antigen DNA cluster had very close identity with the O antigen cluster of an O62 strain. This region of DNA homology included the wzx and wzy genes. Therefore, molecular serotyping tests using only the O41 or O62 wzx and wzy genes would not differentiate between the two serogroups. The E. coli O123 O-antigenic polysaccharide and its repeating unit were characterized, and the chemical structure for E. coli O123 was entirely consistent with the O antigen gene cluster sequences of E. coli O123 and the Salmonella O58 isolates. An understanding of both the genetic and structural composition of Salmonella and E. coli O antigens is necessary for the development of novel molecular methods for serotyping these organisms.
Clark
Clifford G
CG
Department of Medical Microbiology, 510 Medical Sciences Building, University of Manitoba, 730 William Avenue, Winnipeg, MB R3T 2N2, Canada.|Enteric Diseases Program, Bacteriology and Enteric Diseases Program, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB R3E 3R2, Canada.
Kropinski
Andrew M
AM
Laboratory for Foodborne Zoonoses, Public Health Agency of Canada, Guelph, ON N1G 3W4, Canada.
Parolis
Haralambos
H
School of Pharmaceutical Sciences, Rhodes University, Grahamstown 6140, South Africa.
Grant
Christopher C R
CCR
Enteric Diseases Program, Bacteriology and Enteric Diseases Program, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB R3E 3R2, Canada.
Trout-Yakel
Keri M
KM
Enteric Diseases Program, Bacteriology and Enteric Diseases Program, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB R3E 3R2, Canada.
Franklin
Kristyn
K
Laboratory for Foodborne Zoonoses, Public Health Agency of Canada, Guelph, ON N1G 3W4, Canada.
Ng
Lai-King
LK
Department of Medical Microbiology, 510 Medical Sciences Building, University of Manitoba, 730 William Avenue, Winnipeg, MB R3T 2N2, Canada.|Enteric Diseases Program, Bacteriology and Enteric Diseases Program, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB R3E 3R2, Canada.
Paramonov
Nikolay A
NA
School of Pharmaceutical Sciences, Rhodes University, Grahamstown 6140, South Africa.
Parolis
Lesley A S
LAS
School of Pharmaceutical Sciences, Rhodes University, Grahamstown 6140, South Africa.
Rahn
Kris
K
Laboratory for Foodborne Zoonoses, Public Health Agency of Canada, Guelph, ON N1G 3W4, Canada.
Tabor
Helen
H
Enteric Diseases Program, Bacteriology and Enteric Diseases Program, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB R3E 3R2, Canada.
D001483:Base Sequence; D002240:Carbohydrate Sequence; D016000:Cluster Analysis; D004926:Escherichia coli / Q000235:genetics* / Q000276:immunology; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics; D019081:O Antigens / Q000737:chemistry / Q000235:genetics*; D011135:Polysaccharides, Bacterial / Q000737:chemistry / Q000235:genetics*; D019779:Salmonella enterica / Q000145:classification* / Q000235:genetics* / Q000276:immunology; D012703:Serotyping
D019081:O Antigens; D011135:Polysaccharides, Bacterial