Development of an in vitro antibiotics detection technique in samples of beef liver, pork and chicken

With the discovery of antibiotics, millions of lives have been saved, however, its effectiveness has been declining has been declining at the same microorganisms are developing resistance because of their constant exposure during application on the growth of animals for slaugther, so it is necessary to have techniques for the early detection of their presence in food. A cross-sectional and preliminar study was conducted to stablish the feasibility to determine the presence of antibiotics in samples of liver of beef, pork and chicken by inhibiting the growing of the Escherichia coli ATCC25922 strain following the Kirby-Bauer methodology. Fiftheen Petri plates (five for each liver sample: beef, pork and poultry) containing the Mueller Hinton agar were inoculated with the E. coli ATCC25922 strain antibiotic sensitive. In each agar plate a portion of liver of 5 mm of diameter were placed 1 cm away from each inoculum. The plates were incubated at 35 OC for 24 h and the presence of inhibition halos were evaluated. It was found that only one of the fiftheen liver samples analyzed, corresponding to a beef liver, showed a inhibition halo higher than 30 mm. The results obtained indicated the feasibility of using this technique to detect the presence of antibiotics in meat products. El descubrimiento de los antibióticos ha permitido salvar la vida de millones de personas, sin embargo, su efectividad ha ido disminuyendo a la par que los microorganismos van desarrollando resistencia debido a su exposición constante durante su aplicación en el crecimiento de animales de abasto, por lo que se hace necesario contar con técnicas de detección oportuna de su presencia en alimentos. Se realizó un estudio preliminar, de corte transversal, en muestras de hígado de res, cerdo y pollo para establecer la viabilidad de determinar la presencia de antibióticos mediante la inhibición del crecimiento de una cepa de Escherichia coli ATCC25922, utilizando el método de Kirby-Bauer. Se inocularon 15 cajas Petri conteniendo agar Mueller Hinton (cinco para cada muestra de hígado: res, cerdo y pollo), con la cepa E. Coli sensible a antibióticos. En cada caja de agar se colocaron porciones de hígado de 5 mm de diámetro, con 1 cm de distancia entre muestras. Las cajas se incubaron a 35 OC por 24 h y se evaluó la formación de halos de inhibición. Se encontró que sólo una de las 15 muestras de hígado analizadas, correspondiente a hígado de res, presentó un halo de inhibición mayor a 30 mm. Los re