Biofilm former Salmonella enteritidis are multiresistant to antibiotics / Salmonella Enteritidis formadoras de biofilmes são multirresistentes a antimicrobianos

ABSTRACT

Background: The Salmonella Enteritidis is one of the most isolated pathogens in outbreaks of foodborne illness, whichcan occur due to various factors such as cooking temperature, inadequate storage and cross-contamination. The choice ofthe appropriate disinfectant in food industries is essential to prevent the spread of contamination and control of biofilmson surfaces. It is also extremely important the concern with resistance to antimicrobials used both as growth promotersand in human and animal treatments, which may generate a selective pressure favoring the emergence of resistant bacteria.Materials, Methods & Results: Twenty samples of Salmonella Enteritidis were tested, 10 from outbreaks of foodbornediseases and 10 of poultry origin, as for the formation of biofilms, antibiotic resistance and sanitizers. The samples werestored frozen in BHI with 20% glycerol. For reactivation were incubated in BHI broth, plated on XLD agar and subsequentlyperformed biochemical tests to check purity. Firstly were evaluated for biofilm formation on polystyrene at temperature of36 ± 1ºC. We tested the sanitizing resistance to biguanide concentrations 0.6%, 1.0% and 1.5%, peracetic acid at concentrations 0.1%, 0.5% and 1.0%, and quaternary ammonia at concentrations of 0.3%, 1.0% and 2.0%. For tests of antimicrobialresistance the cultures were evaluated front 10 μg ampicillin, 30 μg cephalexin, 30 μg chloramphenicol, 5 μg enrofloxacin,15 μg erythromycin, 30 μg neomycin, 25 μg sulphazotrim, 300 μg sulfonamides. According to the results, 25% of sampleswere strongly biofilm formers, 35% moderately formers, 35% weakly formers and 10% not biofilm formers. In sanitizers, quaternary ammonia and peracetic acid were effective at all concentrations and at all times, but tests with biguanide...