Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Titre : Antibiotic resistance and probiotic properties of lactic acid bacteria isolated from camel milk and shubat

Auteur : Gaukhartas Temirova

Université de soutenance : University of Eastern Finland

Grade : Master of Science (MS) 2016

Résumé
The aim of the study was to identify the lactic acid bacteria (LAB) isolated from camel milk and shubat, to assess their antibiotic resistance profiles and to characterize some of their probiotic properties. The LAB were tested against a set of antibiotics by broth microdilution method, according to standard operating procedures (SOP), and compared to recommendations of the European Food Safety Authority (EFSA). The probiotic properties, such as acid tolerance, bile tolerance and pancreatic enzyme toler ance and the capability to ferment milk, were subjected to testing. Thirteen strains were isolated from camel milk (n=8) and shubat (n=5). Antibiotic resistance profiling method was performed with two types of medium (LSM and MRS). The results turned out to depend on the medium used. MRS broth supported well the growth of LAB, but LSM broth produced more reliable results, particularly in the case of amoniglycoside antibiotics (kanamycin and streptomycin). To assess the probiotic properties, the strains were subjected to simulated intestinal stress factors (low pH, bile acids, pancreatic enzymes). After a 24 h incubation the viability (as CFU/ml) was assessed by plating. One Lactobacillus paracasei and two L. casei (018k-3 и 010k) showed high tolerance in these tests. Accordingly, three Lactobacillus strains could be used as potential antimicrobial probiotic strains against human pathogens and also as starter cultures

Mots clés : lactic acid bacteria, probiotic properties, antibiotic resistance, medium, Lactobacillus

Présentation Version intégrale