Adaptação homóloga e heteróloga de células planctônicas e sésseis de Cronobacter sakazakii a óleos essenciais

Abstract

Cronobacter sakazakii is a pathogenic bacterium that mainly affects newborns, elderly and immunodepressed people and has a high death rate and complications risk. Many cases have been related to use of infant formulas but have also been reported in other foods such as cereals, fruits, vegetables, herbs and spices and animal foods as well as processed foods.C. sakazakiihas peculiar characteristics that allow it to tolerate low water activity, osmotic stresses and extremes of temperature, making it difficult to eliminate them in food processing plants. Another important characteristic is the ability to form biofilm, which guarantees greater resistance to the processes of sanitization and adaptation to the use of bacterial agents.Due to such stress adaptation characteristics several studies have been looking for alternative antimicrobials.Essential oils are natural compounds with antimicrobial action that have different mechanisms of action on the cell and have been shown to be a natural alternative.The mint, ho wood and cinnamon essential oils were tested on Minimum Bactericidal Concentration (MBC) on C. sakazakiiplankton and sessile cells, and after testing the capacity of homologous and heterologous adaptation of C. sakazakii to the oils in the sub concentrations 1 / 8 and 1/16 of the MBC. The MBC found for plankton cells was 0.12% for cinnamon, 0.25% for mint and ho wood, and for sessile cells it was 1.0% for cinnamon and mint and 2.0% for ho wood.The homologous adaptation of plankton cells was observed in ho wood and mint oil with 1/8 MBC and 1/16 MBC and cinnamon oil with 1/16 MBC. And for the sessile cells, only cinnamon oil at concentrations 1/8 and 1/16 presented homologous adaptation. Evaluating the heterologous adaptability, only the cells adapted to the cinnamon oil, in 1/8 and 1/16 of the MBCs and later cultivated in the presence of howood oil, were more sensitive to the same oil.For all other combinations, heterologous adaptability was observed.