ISSN 2736-1756
Advanced Journal of Microbiology Research ISSN 2241-9837 Vol. 13 (1), pp. 001-008, January, 2019. © International Scholars Journals
Full Length Research Paper
Antimicrobial activity and antibiotic resistance of Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus strains isolated from Turkish homemade yoghurts
Asli Akpinar, Oktay Yerlikaya* and Sevda Kiliç
Department of Dairy Technology, Faculty of Agriculture, Ege University, 35100, Bornova – zmir, Turkey.
Accepted 12 January, 2019
Abstract
The aim of this study was to determine the inhibitive effect of 25 Lactobacillus delbruecki ssp. bulgaricus and 16 Streptococcus thermophilus strains isolated from 30 different homemade yoghurts on several pathogen and contaminant bacteria. The antibiotic resistance of these bacteria was also determined. All of Lactobacillus bulgaricus strains exhibited antimicrobial activity against Escherichia coli, whereas all of S. thermophilus strains exhibited the same activity against Klebsiella pneumoniae. None of L. bulgaricus strains were resistant to the polymixin-B, only the OL4 strain has shown resistance to bacitracin. While some strains of S. thermophilus like C6 and SL4 exhibited resistance to novobiocin, SY72, M3, C1M, and F1M were shown to optochin. ET6 and SY73 strains were found to be resistant in both novobiocin and optochin.
Key words: Antibiotic resistance, antimicrobial activity, homemade yoghurt, lactic acid bacteria, Lactobacillus delbrueckii ssp. bulgaricus, Streptococcus thermophilus.