52 research outputs found
Molecular cloning and transcriptional regulation of ompT , a ToxR-repressed gene in Vibrio cholerae
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72189/1/j.1365-2958.2000.01699.x.pd
Molecular analysis of the rstR and orfU genes of the CTX prophages integrated in the small chromosomes of environmental Vibrio cholerae non-O1, non-O139 strains genes of the CTX prophages integrated in the small chromosomes of environmental Vibrio cholerae non-O1, non-O139 strains
The
ctxAB
genes encoding cholera toxin, reside in the
genome of a filamentous bacteriophage CTX φ .The
presence of CTX prophage in non-epidemic environmental
Vibrio cholerae strains is rare. The CTX prophage,
the lysogenic form of CTX φ in V. cholerae , is
comprised of the ‘RS2’ and the ‘Core’. Analysis of the
rstR gene present in the RS2 region of the CTX prophage
revealed the presence of new alleles of the prophages
in four environmental non-O1, non-O139 strains
VCE22 (O36), VCE228 (O27), VCE232 (O4) and VCE233
(O27), and the CTX prophages are located in the small
chromosomes. Phylogenetic analysis based on the
nucleotide sequences of the rstR and orfU (present in
the core) genes of these prophages placed them in a
single unique cluster, which is distally located compared
with that of epidemic V. cholerae O1 strains.
Further analysis indicated that the genome of the
prophage present in the strain VCE22 is devoid of the
ctxAB genes, called pre-CTX prophage and the strain
also possess the toxin-coregulated pilus protein
coding gene tcpA of classical type, another important
pathogenicity determining locus of the epidemic
V. cholerae strains. Comparative analysis of the
nucleotide sequences of the rstR and orfU genes indicated
that the pre-CTX prophage of VCE22 might b
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