Comparison of six commercial systems for the detection of non-O157 STEC in meat and vegetables

MAGDALENA COSTA; ADRIANA SUCARI; SERGIO EPSZTEYN; JUAN OTEIZA; JIMENA GENTILUOMO; CELIA MELAMED; YAMILA FIGUEROA; SANTIAGO MINGORANCE; AGUSTINA GRISARO; SILVIA SPIOUSSAS; MARIANA BUFFONI ALMEIDA; MAILEN CARUSO; ANDRES PONTONI; MARCELO SIGNORINI; GERARDO LEOTTA

FOOD MICROBIOLOGY

ACADEMIC PRESS LTD-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2019

0740-0020

Shiga toxin-producing Escherichia coli (STEC) are important pathogens transmitted by food that may cause severeillness in human beings. Thus, systems for STEC detection in food should have increasingly higher sensitivity andspecificity. Here we compared six commercial systems for non-O157 STEC detection in meat and vegetables anddetermined their sensitivity, specificity and repeatability. A total of 46 samples (meat n= 23; chard n= 23) wereexperimentally contaminated with strains O26:H11, O45:H-, O103:H2, O111:NM, O121:H19 and O145:NM isolated inArgentina. Strain detection was confirmed by isolation according to ISO 13136:2012. Detection of the stx and eaegenes in meat samples was highly satisfactory with all commercial kits, but only five had 100% sensitivity andspecificity in chard. Of four kits evaluated for serogroup detection, three had 100% sensitivity and specificity, and onehad 93.7% sensitivity and 100% specificity. All kits were adequate to analyze meat but not vegetable samples, andwere not therefore validated for the latter matrix. The challenge for microbiology laboratories is to identify theadvantages and disadvantages of the available kits for STEC detection in food based on a clear knowledge of theparticular needs of each laboratory.