Search for LT-II and STb DNA Sequences Among Escherichia coli Isolated from Bovine Meat Products by Colony Hybridization

Abstract

A total of 1,066 Escherichia coli colonies isolated from 105 raw bovine meat samples purchased at supermarkets in Rio de Janeiro were submitted to hybridization assays with gene probes for LT-II and STb enterotoxins. Five colonies comprising four different E. coli strains isolated from four pieces of beef, two samples of ground beef (5.7%) and two hamburger patties (5.7%) hybridized with the LT-II probe, while no hybridization occurred with the STb probe. Expression of LT-II enterotoxin using the Y1 adrenal cell assay was verified in two of four E. coli strains. A serotype diversity existed among LT-II E. coli strains.