the aim of this study was to determine the occurrence of enterotoxigenic and enteroaggregative escherichia coli strains and antibiotic resistance of the isolates in raw milk and unpasteurized cheese. out of 200 samples of raw milk and 50 samples of unpasteurized cheeses, 96 and 24 strains of e. coli were isolated, respectively. polymerase chain reaction (pcr) was used to detect the genes encodi...

Escherichia coli strain 86, isolated from a piglet with diarrhea, carries plasmid-linked genes for resistance to tetracycline, streptomycin, and sulfonamides and for production of heat-labile and heat-stable enterotoxin. Results of (i) genetic experiments involving conjugal transfer and phage P1-mediated transduction and (ii) physical experiments involving electron microscopic examination of pl...

A modified suckling mouse assay was developed for use in field studies whereby five E. coli isolates could be tested as a pool for heat-stable enterotoxin.

Introduction Enteroaggregative Escherichia coli (EAggEC) have been associated with persistent diarrhea in young children, but little is known about its pathogenesis.Weassayed for enterotoxic activity in culture filtrates (CF) of EAggEC strains in Ussing chambers mounted with rabbit ileal mucosa. CF from strain 17-2, a prototype Chilean EAggEC strain, caused a greater rise in potential differenc...

Three enterotoxins from the Aeromonas hydrophila diarrheal isolate SSU have been molecularly characterized in our laboratory. One of these enterotoxins is cytotoxic in nature, whereas the other two are cytotonic enterotoxins, one of them heat labile and the other heat stable. Earlier, by developing an isogenic mutant, we demonstrated the role of a cytotoxic enterotoxin in causing systemic infec...

This enterotoxin retained most of its activity after 30 min. at 1OO"C, but was inactivated after 30 min. at 121°C. It will therefore be referred to as the heat-stable enterotoxin or ST. Although ST could occasionally be detected intracellularly in bacteria grown on soft agar cultures, it was mainly extracellular. In some strains of E. coIi its production was controlled by a transmissible plasmi...