Bacteriophages reduce the number of pathogenic Escherichia coli in mice without altering the gut flora
“We conducted a study to (i) investigate the efficacy of a bacteriophage cocktail against Escherichia coli/Salmonella spp./Listeria monocytogenes (preliminarily called FOP) to reduce a human pathogenic E. coli strain O157:H7 in experimentally infected mice, and (ii) determine how bacteriophages affect the normal intestinal microbiota compared to antibiotic therapy.
A total of 85 mice were inoculated with E. coli O157:H7 strain Ec231 (nalidixic acid-resistant (NalAcR)) via oral gavage and randomized into six groups divided into three categories: Category 1 received PBS or no phage/no PBS (control), Category 2 received either FOP, FOP at 1:10 dilution, or the E. coli phage component of FOP (EcoShield PX™), and Category 3 received the antibiotic ampicillin. All therapies were administered twice daily for four consecutive days, except for ampicillin, which was administered twice on day zero before and after bacterial challenge. Fecal samples were collected on days 0, 1, 2, 3, 5, and 10. The samples were homogenized and plated on LB plates supplemented with NalAc to determine viable Ec231 counts. For trend analysis, individual weights were recorded at each fecal sample collection. (….)
qPCR was performed using specific E. coli primers to quantify the number of E. coli genome copies. Microbiota community profiles were analyzed using denaturing gradient gel electrophoresis (DGGE) and 16S rRNA sequencing. FOP significantly reduced (P < 0.05) the number of E. coli pathogens by more than 55%, with a similar reduction observed with ampicillin therapy. Greater initial weight loss occurred in mice treated with ampicillin (-5.44%) compared to other treatment groups. No notable changes in gut microbiota profiles were observed for control and FOP groups. In contrast, the antibiotic group showed a noticeable distortion of gut microbiota composition, which only partially normalized by day 10. In summary, we found that administration of FOP reduced the viability of E. coli in infected mice with similar efficacy to ampicillin therapy. However, the FOP bacteriophage preparation had a lesser impact on the gut microbiota compared to ampicillin.”
Source:
Bacteriophages reduce pathogenic Escherichia coli counts in mice without distorting gut microbiota
Upuli A. Dissanayake1, 2, 3, Maria Ukhanova3, Zachary D. Moye4, Alexander Sulakvelidze4 and Volker Mai1, 2, 3*
