13 UDK: 579.67:579.869.1 ABSTRACT Sensitivity of 26 Listeria monocytogenes isolates toward 18 antimicrobial substances used in veterinary and human medicine was examined using the automated VITEK 2 Compact system bioMerieux. The obtained results indicate that L. monocytogenes strains isolated from food and food processing environment had resistance to several or more antimicrobial substances that are commonly used in the treatment in animals and humans. Results showed resistance of all 26 (100%) isolates toward Benzylpenicilin, Ampicilin/Sublactam, Oxacillin, Imipenem and Fosfomycine. Also 7 of the isolates (26.9%) were resistant to Clindamiycin, 3 (11.5%) to Quinupristion/ Dalfopristin and 1 strain to Teicoplanin, Vancomycin, Tetracycline and Fusic acid, respectively. Key words: Listeria monocytogenes, antimicrobial resistance, phenotypic similarity, MIC, VITEK 2 INTRODUCTION Genus Listeria is a group of Gram-positive bac- teria. So far there are six identified species: L. mono- cytogenes, L. ivanovii, L. seeligeri, L. innocua, L. welshimeri, and L. grayi, but only L. monocytogenes and L. ivanovii are considered virulent. L. monocy- togenes is an important pathogen that comes from food, but is also isolated from different foodstuffs. Since the first recorded case of listeriosis caused by food occurred in 1981 (1), this foodborne infection is documented in numerous published papers on listeriosis from food around the world (2, 3). Meat, poultry meat, dairy products and vegetable products have been identified as vectors of listeriosis (4, 5, DETECTION OF ANTIMICROBIAL SENSITIVENESS OF ISOLATES OF LISTERIA MONOCYTOGENES FROM FOOD CHAIN USING VITEK 2 COMPACT BIOMERIEUX Jankuloski Dean, Sekulovski Pavle, Angelovski Ljupco, Kostova Sandra, Ratkova Marija, Prodanov Mirko Food Institute, Faculty of Veterinary Medicine, Skopje „Ss. Cyril and Methodius “, Skopje, Macedonia e-mail: djankuloski@fvm.ukim.edu.mk 6). L. monocytogenes is usually sensitive to broad spectrum of antibiotics (7), but after the first isola- tion of multiresistant strain in France in 1988 (9), other resistant strains were isolated from food, food producing premises environment, as well as, spo- radic strains from cases of human listeriosis. The use of antimicrobial substances in animals and hu- mans makes selection of resistant bacteria popula- tions. In feed, despite EC ban on certain antibiotics in veterinary and human medicine (10), antibiotics are being used to control and treatment of diseases caused by bacteria but also as growth promoters (8). Undesirable consequence of use of antibiotics in animals is the potential development of antimicro- bial-resistant zoonotic pathogens in food and their Mac. Vet. Rew. Vol 33, No. 1, 13 - 18, 2010 Original article