DESIGN AND OPTIMIZATION OF A REAL TIME PCR FOR DETECTION OF VIRULENCE GENES ENCODING SHIGA TOXINS 1 AND 2 (STX1 AND STX2) FROM ENTEROHEMORRAGIC Escherichia coli STRAINS

GARRAZA, ROMINA; SALINAS, GABRIEL; JURI AYUB MAXIMILIANO; MANZUR MARÍA JIMENA

Mendoza

Congreso; XL Reunión Científica Anual de la Sociedad de Biología de Cuyo; 2022

Shiga toxin-producing Escherichia coli (STEC) are zoonotic pathogens that cause food-borne diseaseoutbreaks associated with contaminated beef or fresh products, resulting in diarrhea, hemorrhagic colitis,and/or hemolytic uremic syndrome. The pathogenicity of different STEC strains is associated to their abilityto secret shiga toxins (Stx) 1 and/or 2. Therefore, specific and sensitive detection of Stx 1 and Stx 2 encodinggenes is a useful tool for simple detection of STEC food contamination. In Argentina, a common source ofSTEC infections are meat-containing foods, as well as sausages. In this work, we show the setting of amultiplex real time PCR protocol for simultaneous detection and discrimination of Stx 1, Stx 2. In addition,in the same reaction a bovine sequence is detected in order to avoid false negative results arisen from sampledegradation or PCR inhibition. The protocol was validated using genomic DNA purified from three referencestrains provided by the Instituto Nacional de Enfermedades Infecciosas (INEI-ANLIS) “Dr. Carlos G.Malbrán”. The protocol described in this work is proposed as a cost effective approach for detecting foodcontamination with STEC.