Clostridioides difficile specific bacteriophages and the outlook for phagetherapy in intestinal infections

Background and Aim : Clostridioides difficile (C. difficile) has driven consideration as anemerging pathogen responsible for the global spread of outbreak strains, its dynamicepidemiology, and the increasing frequency, acuteness, and health care charges correlated with C.difficile infections (CDI). The increasing emergence of antibiotic-resistant C. difficile hasprompted an exploration of alternative therapeutic options. A promising approach for controllingbacterial disease is the employment of bacteriophages.Methods : C. difficile was isolated from stool samples of hospitalized CDI suspected patients inTehran, Iran. PCR confirmed and determined bacterial toxin profiles. Double-layer agar and spotmethod were employed for isolating C. difficile bacteriophage from hospital sewage which weresubsequently imaged by transmission electron microscopy. The phage's one-step growth curve,efficiency, and host range were investigated in-vitro.Results : Twenty-one of the ۲۸ isolated C. difficile from ۱۸۵ stool samples were toxigenic(۱۱.۳%). Six toxin profile was determined. The highest prevalence belonged to (tcdA+, tcdB+,cdtA-⁄cdtB-) isolates. Bacteriophage isolation from hospital sewage by NaCl was better than withCaCl۲ salt; however, isolation with MgSo۴ salt was unsuccessful. According to the TEM image,a phage belonging to the Siphoviridae family was isolated. The phage was stable at ۲۵ to ۴۵℃ andbetween ۳ to ۱۱ pH. The phage was effective in decreasing C. difficile count in-vitro. A one-stepgrowth chart with nonlinear regression analysis showed high correspondence with the logisticgrowth pattern, with an estimated latent phage period of around ۳۰ minutes. Among the ۲۸toxigenic C. difficile isolates with six toxin profiles, the phage has shown a lytic effect against۷۰% of those strains.Conclusion : It appears that lytic phages have the potential of becoming an alternative therapeuticoption for mitigation of CDI since it has advantageous functions in eliminating C. difficile and hasno effect on other bacteria in the gut microbiome.

کلیدواژه ها:

Clostridioides difficile ، CDI ، Bacteriophage