Antimicrobial activity and Probiotic Properties of Lactic Acid Bacteria Isolated From Traditional Fermented Dairy Products

Abstract

One of the biggest problems for humans and animals worldwide is the harmful effects of the antibiotics, due to excessive use as a treatment for animal diseases. An alternative to overcome this problem is the use of certain growth promoters such as probiotics that have a good effect on host health and performance. Eight isolates included the following probiotic strains: Lactobacillus plantarum, L. acidophilus, L.rhamnosus, L. salivarius, and L. paracasei, as well as Bifidobacterium longum, B. adolescentis, and B. breve were investigated for low pH and bile salt tolerance, anti-bacterial and yeast activity using supernatant cell-free culture were assessed using agar-well diffusion method against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, , Escherichia coli MC1400 Listeria ivanovii and Candida albicans. Co-culture has determined the antifungal activities with Aspergillus niger, As. flavous, As. fumigatus and Penicillium chrysogenum. The antibiotic sensitivity was tested using the agar disc diffusion method. Each of the strains examined had variable antibacterial activity. All the isolates showed a variable inhibition level, as well. All of the isolates were Ciprofloxacin resistant. Additionally, the lactobacilli strains were Vancomycin-resistant, and all of the strains show intermediate Clindamycin resistance. All isolates were Penicillin, Ampicillin, Tetracycline, Erythromycin, Gentamycin, Streptomycin, Florfenicol, Chloramphenicol, and Sulfamethoxazole & Trimethoprim susceptible. Collectively, the probiotic capacity of the strains tested and the antimicrobial activity without the transfer of antibiotic resistance suggested that these strains can be used as bio-preservatives in food products and medicinal preparations.