IMPROVEMENT OF THE POLYMERASE-CHAIN-REACTION TO DETECT ESCHERICHIA-COLI SHIGA-LIKE TOXIN-II GENE FROM CLINICAL ISOLATES

The polymerase chain reaction was improved to detect Escherichia coli Shiga-like toxin a gene from clinical isolates. Concentrations of bact erial DNA, primers SLT-II1 and SLT-II2, and MgCl2 were modified up to obtain the cleanest electrophoretic pattern and the highest yield of S LT-II amplimer. T-m was calculated using the formulae 2(A + T) + 4(G C) and %(G + C), although the best results were obtained with the lat ter. The: sample preparation method and the experimental conditions es tablished were applicable to E. coli strains isolated from clinical sa mples, allowing a rapid, sensitive and more specific screening.