Abstract

ACUNA, Patricia et al. Standardization of a multiplex PCR technique for the detection of Shiga toxin-producing Escherichia coli (STEC) serogroups O157, O104 and "big six". Mem. Inst. Investig. Cienc. Salud [online]. 2019, vol.17, n.2, pp.71-76. ISSN 1812-9528.  https://doi.org/10.18004/mem.iics/1812-9528/2019.017.02.71-076.

STEC serogroups O26, O45, O103, O104, O111, O121, O145, and O157, are related to a high number of cases of HUS worldwide, so they are included in the categories of greatest risk for humans, according to the food administration criteria of the United States and Europe. The conventional method of identifying antigens O and H is carried out by agglutination with rabbit antisera. This method is very expensive and laborious and is not available in the country for massive-scale use. In this context, the objective of this cross-sectional descriptive observational study has been the standardization of a multiplex PCR technique for the detection of these 8 serogroups, in order to have an efficient and sensitive detection system with the potential for application in the food industry. PCR reactions were standardized using as positive controls reference E. coli strains to correspond to all the mentioned serogroups. Products of expected sizes were obtained for each serogroup; no cross-amplification or false positives were observed. This standardized technique could represent a quick and less expensive tool than the serological technique, with the possibility to be applied to different kind of samples, allowing the detection of these serogroups in STEC isolates of live cattle, sources of drinking water, food and even in clinical isolates associated with human diseases.

Keywords : STEC; O157; O104; big six serogroups; PCR.

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