AUTHOR=Mantzourani Ioanna , Bontsidis Christos A. , Plessas Stavros , Alexopoulos Athanasios , Theodoridou Eirini , Tsigalou Christina , Voidarou Chrysa , Douganiotis George , Kazakos Stavros L. , Stavropoulou Elisavet , Bezirtzoglou Eugenia 

TITLE=Comparative Susceptibility Study Against Pathogens Using Fermented Cranberry Juice and Antibiotics

JOURNAL=Frontiers in Microbiology

VOLUME=10

YEAR=2019

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2019.01294

DOI=10.3389/fmicb.2019.01294

ISSN=1664-302X

ABSTRACT=<p>In the present study, unfermented and fermented cranberry juice in combination with the Antibiotics vancomycin and tigecycline were tested for their antimicrobial activity. Cranberry juice was fermented with a recently isolated potentially probiotic <italic>Lactobacillus paracasei</italic> K5. The tested strains selected for this purpose were <italic>Enterococcus faecalis, E. faecium, Enterobacter cloacae</italic> and <italic>Staphylococcus aureus</italic>. The methods followed were the determination of zones inhibition, Minimum Inhibitory Concentration (MIC) and Fractional Inhibitory Concentration Index (FICI). Tigecycline together with fermented juice exhibited larger Zones of Inhibition (ZOI) in strains of <italic>E. faecium</italic> (65 ± 4.8 mm) compared to the respective ZOI with tigecycline and unfermented juice (no zone). The same outcome was also obtained with <italic>E. cloacae</italic>. Vancomycin together with fermented juice exhibited larger ZOI in strains of <italic>E. faecium</italic> (28 ± 2.2 mm) compared to the respective ZOI with vancomycin and unfermented juice (24 ± 2.3 mm). The lowest MIC values were recorded when tigecycline was combined with fermented cranberry juice against <italic>S. aureus</italic> strains, followed by the same combination of juice and antibiotic against <italic>E. cloacae</italic> strains. FICI revealed synergistic effects between fermented juice and tigecycline against a strain of <italic>E. faecium</italic> (A2020) and a strain of <italic>E. faecalis</italic> (A1940). Such effects were also observed in the case of fermented juice in combination with vancomycin against a strain of <italic>S. aureus</italic> (S18), as well as between fermented juice and tigecycline against <italic>E. cloacae</italic> (E1005 and E1007) strains. The results indicate that the antibacterial activity of juice fermented with the potentially probiotic <italic>L. paracasei</italic> K5 may be due to synergistic effects between some end fermentation products and the antibiotic agents examined.</p>