Premium
Expression of colonization factor antigen I fimbriae by enterotoxigenic Escherichia coli; influence of growth conditions and a recombinant positive regulatory gene
Author(s) -
HALVORSEN THOMAS,
VALVATNE HÅVARD,
GREWAL HARLEEN M. S.,
GAASTRA WIM,
SOMMERFELT HALVOR
Publication year - 1997
Publication title -
apmis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.909
H-Index - 88
eISSN - 1600-0463
pISSN - 0903-4641
DOI - 10.1111/j.1699-0463.1997.tb00565.x
Subject(s) - biology , escherichia coli , microbiology and biotechnology , enterotoxigenic escherichia coli , fimbria , recombinant dna , plasmid , bacteria , gene , transformation (genetics) , mutant , gene expression , genetics , enterotoxin
Enterotoxigenic Escherichia coli (ETEC) may spontaneously lose the positive regulatory cfaR gene and thereby the capacity to express colonization factor antigen I (CFA/I). A recombinant plasmid harbouring the cfaR gene was transformed into cfaR ‐negative mutant ETEC strains. CFA/I expression of wild‐type and cfaR ‐transformed ETEC cultivated in different liquid media was quantified. At 37°C, a high level of CFA/I expression from wild‐type and cfaR ‐transformed strains was observed after growth in CFA broth. Transformation enhanced CFA/I expression only marginally. The transformant cultures showed a considerable variation in CFA/I expression which was paralleled by the proportion of individual bacteria producing CFA/I. This heterogeneity could be explained by a variable tendency to structural CFA/I gene loss among individual cfaR ‐transformed bacteria.