Detection with synthetic oligonucleotide probes of nucleotide sequence variations in the genes encoding enterotoxins of Escherichia coli.
We examined variations in the genes encoding heat-stable enterotoxin (ST) and heat-labile enterotoxin (LT) in 88 strains of Escherichia coli isolated from individuals with traveler's diarrhea to find suitable sequences for use as oligonucleotide probes. Four oligonucleotide probes of the gene encoding ST of human origin (STIb or STh), one oligonucleotide probe of the gene encoding ST of porcine origin (STIa or STp), and three oligonucleotide probes of the gene encoding LT of human origin (LTIh) were used in DNA colony hybridization tests. In 15 of 22 strains possessing the STh gene and 28 of 42 strains producing LT, the sequences of all regions tested were identical to the published sequences. One region in the STh gene examined with a 18-mer probe was relatively well conserved and was shown to be closely associated with the enterotoxicity of the E. coli strains in suckling mice. This oligonucleotide, however, hybridized with strains of Vibrio cholerae O1, V. parahaemolyticus, and Yersinia enterocolitica that gave negative results in the suckling mouse assay.
Nishibuchi
M
M
Research Institute for Microbial Diseases, Osaka University, Japan.
Murakami
A
A
Arita
M
M
Jikuya
H
H
Takano
J
J
Honda
T
T
Miwatani
T
T
D000818:Animals; D000833:Animals, Suckling; D001427:Bacterial Toxins / Q000235:genetics*; D001483:Base Sequence; D001681:Biological Assay; D015342:DNA Probes; D004269:DNA, Bacterial / Q000235:genetics; D003967:Diarrhea / Q000382:microbiology; D004768:Enterotoxins / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000382:microbiology; D029968:Escherichia coli Proteins; D005798:Genes, Bacterial; D014644:Genetic Variation; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization
D001427:Bacterial Toxins; D015342:DNA Probes; D004269:DNA, Bacterial; D004768:Enterotoxins; D029968:Escherichia coli Proteins; C034151:heat stable toxin (E coli); C027538:heat-labile enterotoxin, E coli