Identificação e perfil de resistência de cocos grampositivos isolados de ordenhadeiras no Sul do Rio Grande do Sul, Brasil

Abstract

Milk is a high nutritional value food that helps in human development and growth, however, it can also harbor micro-organisms that alter its composition and produce enzymes and toxins as part of its metabolism. Many of these micro-organisms are resistant to antibiotics and disinfectants used in the industry, thus highlighting the importance of care ranging from obtaining to storing milk. Therefore, the objective of this work was to isolate, identify and evaluate the resistance profile and pathogenicity factors of gram-positive cocci isolated from liners in milking rooms in the south of Rio Grande do Sul, Brazil. Collections were performed with swabs from initial liners and the identification was performed through biochemical and molecular tests. Seventeen bacteria were isolated, identified as Enterococcus faecalis (10), Enterococcus faecium (4), Staphylococcus intermedius (1), Streptococcus uberis (1) and Streptococcus dysgalactiae (1). After the identifications, the antibiogram was performed with the evaluation of 13 antibiotics. The genus that proved to be resistant to most of these was the Enterococcus. In addition, all 17 isolates were able to form biofilm, which remained viable after the use of neutral, alkaline and alkalinechlorinated detergent. The only product that was effective against biofilm of all microorganisms was chlorhexidine 2%. The results obtained in this work highlight the importance of pre- and post-dipping tests on dairy properties, in which chlorhexidine is one of the disinfectants used, since, as observed, products indicated for cleaning and descaling pipes were not effective on biofilms of the different species tested.