A partially purified preparation of the heat-stable enterotoxin of Escherichia coli caused a rapid and persistent increase in electric potential difference and short-circuit current when added in vitro to the luminal surface of isolated rabbit ileal mucosa. As little as 1 ng/ml produced an easily detectable response. Under short-circuit condition, the enterotoxin abolished net Cl- absorption; t...

Aeromonas hydrophila is an opportunistic pathogen of a variety of aquatic animals that displays extreme diversity in drug resistance, phenotypes, virulence genes, and virulence. In this study, eight pathogenic A. hydrophila strains were isolated from diseased Amur sturgeons and investigated for their sensitivity to select antibiotics, their phenotype, virulence genes, and virulence. According t...

methods this experimental study was conducted on iranian children communities from may to november 2014. forty stool samples were obtained from laboratories and investigated for heat-labile toxin (lt). specific primers were designed and the dig -labeled pcr products were bounded to streptavidin-coated wells of a microtiter plate and detected by anti-dig-peroxidase conjugate. an internal biotin-...

materials and methods two-hundred pasteurized (n = 100) and nonpasteurized (n = 100) cheese samples were collected. the initial isolation was performed on pemba specific medium. antibiotic susceptibility testing was performed using several antibiotic disks, according to the guidelines of the clinical laboratory and standards institute. specific primers amplifying the hbla enterotoxin-encoding g...

A conjugative plasmid with potential usefulness for vaccine strains was constructed. In the first step, a 5.9-kilobase DNA segment containing the two loci for the A and B subunits of heat-labile enterotoxin with a mutation in the gene for the A subunit was joined to the cloning vehicle pGA22, generating the nonconjugative plasmid pPMC4 with genes for resistance to tetracycline and chloramphenic...