<?xml version="1.0" encoding="ISO-8859-1"?><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<front>
<journal-meta>
<journal-id>1812-9528</journal-id>
<journal-title><![CDATA[Memorias del Instituto de Investigaciones en Ciencias de la Salud]]></journal-title>
<abbrev-journal-title><![CDATA[Mem. Inst. Investig. Cienc. Salud]]></abbrev-journal-title>
<issn>1812-9528</issn>
<publisher>
<publisher-name><![CDATA[Instituto de Investigaciones en Ciencias de la Salud]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S1812-95282019000200071</article-id>
<article-id pub-id-type="doi">10.18004/mem.iics/1812-9528/2019.017.02.71-076</article-id>
<title-group>
<article-title xml:lang="es"><![CDATA[Estandarización de una técnica de PCR múltiple para la detección de los serogrupos O157, O104 y &#8220;big six&#8221; de Escherichia coli productora de la toxina Shiga (STEC)]]></article-title>
<article-title xml:lang="en"><![CDATA[Standardization of a multiplex PCR technique for the detection of Shiga toxin-producing Escherichia coli (STEC) serogroups O157, O104 and "big six"]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Acuña]]></surname>
<given-names><![CDATA[Patricia]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Florentín]]></surname>
<given-names><![CDATA[Melisa]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Rojas]]></surname>
<given-names><![CDATA[Natalia]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Rodríguez]]></surname>
<given-names><![CDATA[Fátima]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Guillén]]></surname>
<given-names><![CDATA[Rosa]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
</contrib-group>
<aff id="Af1">
<institution><![CDATA[,Universidad Nacional de Asunción Instituto de Investigaciones en Ciencias de la Salud Departamento de Microbiología]]></institution>
<addr-line><![CDATA[San Lorenzo ]]></addr-line>
<country>Paraguay</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>08</month>
<year>2019</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>08</month>
<year>2019</year>
</pub-date>
<volume>17</volume>
<numero>2</numero>
<fpage>71</fpage>
<lpage>76</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://scielo.iics.una.py/scielo.php?script=sci_arttext&amp;pid=S1812-95282019000200071&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://scielo.iics.una.py/scielo.php?script=sci_abstract&amp;pid=S1812-95282019000200071&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://scielo.iics.una.py/scielo.php?script=sci_pdf&amp;pid=S1812-95282019000200071&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="es"><p><![CDATA[RESUMEN Los serogrupos O26, O45, O103, O104, O111, O121, O145 y O157 de STEC se relacionan con un elevado número de casos de SUH a nivel mundial, por lo que están incluidos dentro de las categorías de mayor riesgo para los humanos, según los criterios de autoridades alimentarias de Estados Unidos y Europa. El método convencional de identificación de antígenos O y H se realiza por aglutinación con antisueros de conejo. Este método además de ser muy costoso y laborioso, no se encuentra disponible en el país para empleo masivo. En este contexto, el objetivo de este estudio observacional descriptivo de corte transverso ha sido la estandarización de una técnica de PCR múltiple para la detección de estos 8 serogrupos, a fin de contar con un sistema de detección eficiente, sensible y con potencial de aplicación en la industria alimentaria. Se estandarizaron reacciones de PCR empleando como controles positivos cepas E. coli de referencia correspondientes a la totalidad de los serogrupos citados. Se obtuvieron productos de tamaños esperados para cada serogrupo, no se observaron amplificaciones cruzadas o falsos positivos. Esta técnica estandarizada podría representar una herramienta rápida y menos costosa que la técnica serológica, con la capacidad de ser aplicada a diferentes matrices, permitiendo la detección de estos serogrupos en aislados STEC de ganado en pie, fuentes de agua de consumo, alimentos e incluso en aislamientos clínicos asociados a enfermedades humanas.]]></p></abstract>
<abstract abstract-type="short" xml:lang="en"><p><![CDATA[ABSTRACT 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.]]></p></abstract>
<kwd-group>
<kwd lng="es"><![CDATA[STEC]]></kwd>
<kwd lng="es"><![CDATA[O157]]></kwd>
<kwd lng="es"><![CDATA[O104]]></kwd>
<kwd lng="es"><![CDATA[serogrupos &#8220;big six&#8221;]]></kwd>
<kwd lng="es"><![CDATA[PCR]]></kwd>
<kwd lng="en"><![CDATA[STEC]]></kwd>
<kwd lng="en"><![CDATA[O157]]></kwd>
<kwd lng="en"><![CDATA[O104]]></kwd>
<kwd lng="en"><![CDATA[big six serogroups]]></kwd>
<kwd lng="en"><![CDATA[PCR]]></kwd>
</kwd-group>
</article-meta>
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