Avaliação da qualidade de leite pasteurizado com inspeção estadual pela pesquisa de estafilococos coagulase positiva, resistência antimicrobiana e formação de biofilme

Abstract

Milk is an alternative source of proteins accessible to the low income population, which is generally lacking in animal protein, proving the socioeconomic importance of this food. In public health, particularly in the area of sanitary food surveillance, Staphylococcus aureus, the main staphylococci of positive coagulase, is considered one of the most frequent cause of outbreaks of foodborne diseases. Milk and milk products are among the foods most involved in the outbreaks identified and studied. The objective of this study was to evaluate the quality of pasteurized milk with state inspection by the positive coagulase staphylococci, its antimicrobial resistance and the ability to form biofilm. The study was carried out in Alagoas and 75L of pasteurized milk were collected from five processing plants and three different lots in the municipalities of Maceió, Coruripe, Capela, Chã Preta and Quebrangulo. Positive coagulase staphylococci (PCS) was performed using Baird-Parker Agar medium, rabbit plasma and brain-heart infusion broth. The PCS were submitted to the antibiogram by means of inoculation in Müller Hinton broth and the discs were applied with the drugs: gentamicin (5μg), amoxicillin (10mcg), polymyxin (300mg), erythromycin (10μg), penicillin (10μg), ampicillin (10μg), tetracycline (30μg), sulfazotrim (25μg) and cephalexin (30μg). The phenotypic characterization of PCS was also performed by the ELISA plate adhesion method for biofilm formation. Of the 75 samples, 4 (5.3%) samples were identified with PCS. The count ranged from 1,2x104 a 2,6x105CFU/mL-¹. Isolated PCS showed 100% sensitivity to all antimicrobials tested and none were biofilm forming. The quality of pasteurized milk with state inspection of the study in relation to the presence of coagulase positive staphylococci is inadequate for consumption. The sensitivity of PCS to all antimicrobials and non-biofilm formation reduces the risk that these microorganisms could cause to public health.