Open AccessAntagonistic Potential of Dairy Origin Enterococcus faecium Against Multidrug-Resistant Foodborne Pathogens
Author(s) -
Sana Waheed,
Muhammad Hidayat Rasool,
Bilal Aslam,
Saima Muzammil,
Muhammad Waseem,
Muhammad Shahid,
Muhammad Saqib,
Sumreen Hayat,
Muhammad Naeem,
Zeeshan Taj,
Saba Kabir,
Muhammad Saqalein,
Muhammad Atif Nisar,
Mohsin Khurshid
Publication year - 2021
Publication title -
romanian biotechnological letters
Language(s) - English
Resource type - Journals
eISSN - 2248-3942
pISSN - 1224-5984
DOI - 10.25083/rbl/26.2/2406.2415
Subject(s) - microbiology and biotechnology , enterococcus faecium , probiotic , biology , kanamycin , tetracycline , bacteriocin , gentamicin , broth microdilution , antibiotics , antimicrobial , bacteria , minimum inhibitory concentration , genetics
Probiotic potential of Enterococcus spp. is widely investigated around the globe. The biochemically and molecular characterized E. faecium strains isolated from Dahi (continental yogurt) were evaluated to tolerate simulated gastric environment, bile, sodium chloride, temperature, and pH. The safety was assessed by disc diffusion, broth microdilution, antibiotic resistance genes screening, and hemolytic ability. Enterococci survived simulated gastrointestinal conditions and depicted growth at temperature (15 to ≥42°C), pH (≤2.5 to ≥9.5), 0.3% bile salt and 3% NaCl. All strains were sensitive to ampicillin, vancomycin, kanamycin, gentamicin, streptomycin, tetracycline and ciprofloxacin and harbored vanR, vanX, qnrB2, qnrS, tetK, and tetW resistance genes. E. faecium strains inhibited the E. coli (85%) and S. Typhi (50%) whereas the 10% cell-free culture supernatant (CFCS) of E. faecium halted the growth of E. coli while 15% CFCS completely suppressed S. Typhi. The cell-free culture supernatant retained antibacterial nature after pH and proteinase K treatment, however, it lost activity after heat treatment (≥95°C). The genetic screening revealed that all isolates are capable to produce putrescine biogenic amine. Further assessment of strains for lack of infectivity, cytotoxicity in animals, adhesion to Caco-2 cells and characterization of enterocins is essential to conclude the probiotic potential of these strains.