ANTIBIOTIC RESISTANCE OF LACTOBACILLI STRAINS ISOLATED FROM MILK AND MILK PRODUCTS FROM MIDDLE SLOVAKIA

The aim of this study was to determine the antibiotic susceptibility of lactobacilli strains isolated from milk and milk products from middle Slovakia. The 42 samples of milk and milk products were collected from sheep farming from middle Slovakia. MRS agar was used for this cultivation. It was done at 37 °C during 36-48 hours in CO2 box with 10 % CO2. Identification of lactobacilli strains was done by Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry with Biotyper software – MALDI TOF MS Biotyper. Four anitibiotics M.I.C. We used four anitibiotics M.I.C. evaluators strips for antibiotic susceptibility testing. These antibiotics were used in this experiment: erythromycin (E 256 – 0.015 μg/ml), ampicillin (AMP 256 – 0.015 μg/ml), gentamycin (CN 256 – 0.015 μg/ml) and tetracycline (TE 256 – 0.015 μg/ml). We isolated 42 lactobacilli strains and identified them as Lactobacillus plantarum and Lactobacillus spp. We isolated 7 strains of Lactobacillus plantarum and 35 isolates were Lactobacillus spp. From the seven isolates of Lactobacillus plantarum 3 isolates were resistant to ampicillin (MIC 16 μg/ml in 2 isolates and MIC 12 μg/ml in one isolate) and one resistant to tetracycline (MIC 16 μg/ml). From 35 isolates of Lactobacillus spp. 9 isolates were resistant to erytromycin (32 μg/ml), 10 isolates resistant to ampicillin (MIC 16 μg/ml in 4 isolates, MIC 12 μg/ml in 5 isolates and MIC 4 μg/ml in one isolate), 5 isolates resistant to tetracycline (16 μg/ml). Resistance to gentamycin was not detected. Lactobacilli isolated from milk and milk products were resistant to erytromycin (resistanece was 21.42 %), ampicillin (resistance was 30.95 %) and tetracycline (resistance was 14.28 %) and were sensitive in 100 % to gentamycin.