Open AccessEnterotoxin‐associated DNA sequence homology between Salmonella species and Escherichia coli
Author(s) -
Chopra A.K.,
Peterson J.W.,
Houston C.W.,
Pericas R.,
Prasad R.
Publication year - 1991
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1991.tb04336.x
Subject(s) - biology , escherichia coli , southern blot , microbiology and biotechnology , salmonella typhi , restriction map , salmonella , dna , homology (biology) , ecori , restriction fragment , hindiii , genetics , plasmid , gene , bacteria
Summary Multiple Hin dIII‐restriction fragments of Salmonella typhimurium and Salmonella typhi chromosomal DNA exhibited homology with the heat‐labile enterotoxin (LT1) gene of Escherichia coli as determined by Southern blot analysis. A 9.4 kb Hin dIII restriction fragment identified in S. typhimurium and S. typhi chromosomal DNA reacted with both eltA and eltB gene probes. However, the homology of the 9.4 kb DNA fragment from these Salmonella species was greater with eltB than eltA . In addition, a synthetic oligonucleotide probe, made to a portion of the putative G M1 ‐ganglioside binding region of cholera toxin (CT) and LT1, hybridized with the 9.4 kb DNA fragment of S. typhimurium but not with the 9.4 kb fragment found in S. typhi isolates. The hybridization of multiple restriction fragments of Salmonella DNA with eltA and eltB gene sequences further suggests duplication of the stx operon on the chromosome of these bacteria.