MONITORING BACTERIAL ANTIBIOTIC RESISTANCE AND AGROCHEMICAL RESIDUES IN FRESH CUT PRODUCTS

PONCE ALEJANDRA; BLANDO MARTIN ; MEDICI SANDRA

Mar del Plata

Congreso; SCYTAL; 2017

AATA

Chemicals commonly used in agriculture, domestic gardens, and public places are increasingly inducing a multiple antibiotic resistance phenotype in potential pathogens. This effect occurs due to simultaneous exposure to antibiotics and it is faster than the antibiotics lethal effect. The presence of microbial resistance to beta-lactam antibiotics can be detected through the presence of metallo-beta-lactamasas enzymes.The objectives of this work were to: 1) isolate and characterize strains of public interest of fresh cut products from Mar del Plata city; 2) determine microorganisms that present metallo-beta-lactamasas enzymes through a phenotypic method and 3) determine the existence of agrochemical residues in these products.Strains isolation was carried out from homogenates of lettuce, parsley, celery, broccoli, Swiss chard, beetroot, fennel, green onion, red cabbage, lettuce seeds and carrots. Strains molecular characterization was carried out by the PCR technique. The antimicrobial susceptibility study for the phenotypic detection of metallo-beta-lactamase enzymes was done using the Muller Hinton Agar Diffusion method according to CLSI standards. Finally, the presence of agrochemical residues (organochlorated pesticides, organophosphorus, pyretroides, carbamates, fungicides, herbicides and phenyl pyrazoles) from the fresh-cut samples was carried out by Gas Chromatography- Mass Selective Detector.A total of 28 bacterial strains were isolated and characterized. Among the isolated strains, microorganisms of the genus Staphylococcus spp., Enterococcus spp.; Serratia spp. Escherichia spp. and Pseudomona spp. were found. These genus are important as priority microorganisms recognized by the WHO, which need new antibiotics to be combated. According to this, five of the total strains tested (genus: Serratia spp., Leuconostoc spp., Enterococcus spp.) were positive against the antimicrobial susceptibility study for the phenotypic detection of metallo-beta-lactamase enzymes.The results obtained from the eleven vegetable samples showed presence of agrochemicals; only on samples of Swiss chard and cabbage. The Swiss chard sample showed residues of organophosphorus pesticides (2.68 mg / kg) and pyrethroids (0.08 mg / kg), and the red cabbage sample presented pyrethroid residues (0.04 mg / kg). The combination of abusive use of both agrochemicals and antibiotics in proximity to farms might also compromise their therapeutic effects and consequently, a greater use of antibiotics is needed. To address the antibiotic resistance crisis broadening our view of its environmental contributors is required.