The present work was carried out with the objective of detecting the presence of stx1, stx2, ehxA, saa, eae, elt, est, aggR, ipaH genes all of them coding for virulence factors of DECs in fecal samples of cattle.CONACYT – Consejo Nacional de Ciencia y TecnologíaPROCIENCI

Guillén, Rosa María

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Guillén Fretes, Rosa María

Repositorio Institucional CONACYT

Rojas M.N., Martínez-Pavetti A., Rodríguez F., Guillén R. Molecular Biology and Biotechnology Department, IICS, UNA, Asunción, Paraguay. rmguillenf@gmail.comINTRODUCTIONEscherichia coli are a gram-negative bacillus present in thenormal intestinal flora of humans and animals. However, certainstrains can cause diarrheal disease, and are calleddiarrheogenic E. coli (DEC). DECs include enterotoxigenic(ETEC), enteropathogenic (EPEC), enteroinvasive (EIEC),enteroaggregative (EAEC), and Shiga toxin producing (STEC)strains of E. coli. The intestinal tract of cattle constitutes one ofthe main reservoirs of DECs, humans are infected through theingestion of contaminated meat products. The present workwas carried out with the objective of detecting the presence ofstx1, stx2, ehxA, saa, eae, elt, est, aggR, ipaH genes all ofthem coding for virulence factors of DECs in fecal samples ofcattle1-3.MATERIALS Y METHODS.CONCLUSIONSThe high frequency of STEC-related gene bovine carriersrepresents a problem for public health, because failures ingood hygiene practices in the production chain can lead tocontamination of the meat products that constitute thesource of transmission to humans. These resultsdemonstrate the need to establish control systems in themeat production chain, from animal breeding to final productthat is why we consider that the molecular methods used inthis study are excellent alternative for this purpose.REFERENCES1. Nataro JP, Kaper JB. Diarrheagenic Escherichia coli. Clin Microbiol Rev.1998;11(1):142-201.2. Robins-Browne RM. Traditional Enteropathogenic Escherichia coli ofInfantile Diarrhea. Rev Infect Dis. 1987;9(1):28–53.3. Wang F, Jiang L, Yang Q, Prinyawiwatkul W, Ge B. Rapid and specificdetection of Escherichia coli serogroups O26, O45, O103, O111, O121, O145,and O157 in ground beef, beef trim, and produce by loop-mediated isothermalamplification. Appl Environ Microbiol. 2012;78(8):2727–36.SampleRectal swab taken from cattle selected byconvinience methodMicrobiological analysisCulture on McConkey agar at 37°C – 24 HsDNA ExtractionBoiling method to extract DNA from theconfluent bacterial growing zonePCRDetection of genes: stx1, stx2, ehxA,saa, eae, elt, est, aggR, ipaH (Fig 1)Design: A cross sectional study was approved by the Scientific and Ethics Committees of the Health Science Research Institute of Paraguay.  This study included one farm that have cattle for meat production. Fecal samples were taken using a rectal swab and the workflow were as follow RESULTSThe frequency of animals bearing STEC-related genes was: • 82% (41/50) for stx1 and/or stx2• 74% (37/50) for ehxA, and 68% (34/50) for saa. • In 2% (1/50) of the animals eae was detected, it can mean the presence of EPEC or STEC strains. • The elt, est, aggR, and ipaH genes associated with the ETEC, EAEC, and EIEC pathotypes respectively were not detected. (Table 1)Figure 1. Amplification of DEC genes by PCR. Electrophoresison 2% agarose stained by ethidium bromide.Samples Virulence Factor - Pathotypeelt-ETECest-ETECeae-EPECipaH-EIECaggR-EAECStx½STECsaa-STECexhA-STEC% - - 2% - - 82 68 74n - - 3 - - 41 34 37Table 1. Frequency of animals bearing STEC-related genesFrequency of virulence genes related to diarrheogenic E. coli in cattle from Cordillera Department of Paraguay in 2016.

Frequency of virulence genes related to diarrheogenic E. coli in cattle  from Cordillera Department of Paraguay in 2016

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Frequency of virulence genes related to diarrheogenic E. coli in cattle from Cordillera Department of Paraguay in 2016

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