Eduardo Mere Del Aguila
Federal University of Rio de Janeiro, Brazil
Title: Molecular, biochemical and immunological testing on the diagnosis of potential risk of food poisoning by coagulase negative Staphylococcus in products from animal origin
Biography
Biography: Eduardo Mere Del Aguila
Abstract
Food from animal origin, such as milk, dairy derivatives and meat, can often be contaminated with staphylococci-enterotoxigenic strains. Contamination may occur directly from infected animals, inadequate processing, like contamination of starter cultures, or may result from poor hygiene during food manufacturing, retail and storage. Twenty-nine coagulase-negative staphylococci strains isolated from Minas frescal cheese and Italian-type salami were identified by 16S rDNA sequencing: saprophyticus, xylosus, sciuri, carnosus, succinus, epidermidis, hominis and piscifermentans. A phylogenetic analysis grouped the strains into five major groups composed of 2 refined clusters containing subclusters, where strains showed similarities over 90%. Enterotoxin-encoding genes - sea, seb and sec - showed a high prevalence in the genomes. The sei, seh, selm and seln genes were harbored by at least 33% of the strains. The tstH1genes were found in 7% of the salami strains. Fifteen strains were able to transcript at least one type of mRNA enterotoxin, as evidenced by real time RT-PCR assays. In vitro production of the enterotoxin SEA-SEE was detected in almost all strains by ELISA assays. All strains showed multi-resistance to antimicrobials, such as ß-lactams, vancomycin and linezolid, which show both human and veterinarian medicine therapeutic importance. MICs ≤ 0.06 mg/mL for methicillin, ampicillin and vancomycin and ≤ 0.25 mg/mL for linezolid were observed. High risk of food poisoning following the consumption of improperly manufactured animal origin products was emphasized, as well as the possibility of these food matrices acting as reservoirs for antibiotic resistance, spreading pathogenic strains.