In vivo lysogenization of a Clostridium difficile bacteriophage ФCD119

Abstract

Clostridium difficile is a nosocomial pathogen identified as the cause of antibiotic associated diarrhea and colitis. In this study, we have documented the lysogeny of a C. difficile bacteriophage in hamsters during C. difficile infection. The lysogens isolated from the hamsters were toxin typed and their phage integration site was confirmed by PCR. Through toxin ELISA it was found that the toxin production in the in vivo isolated lysogens was affected due to ΦCD119 lysogenization as in the case of in vitro isolated ΦCD119 lysogens. Together our findings indicate that a baceriophage can lysogenize its C. difficile host even during the infection process and highlights the importance of lysogeny of C. difficile phages as an evolutionary adaptation for survival.

Bacteriophage Combinations Significantly Reduce Clostridium difficile Growth In Vitro and Proliferation In Vivo

“…No strictly virulent C. difficile phages have been isolated, despite the efforts of several research groups ( 60 – 62 ). This has hampered their development for therapeutic use, as temperate phages are considered undesirable due to their capacity to transduce or lysogenize infected bacteria ( 30 , 31 , 34 ). In reality, many phage mixtures effective against other target bacteria have been produced, and in those studies, phages were selected solely on the basis of their activity in vitro and in vivo ( 25 ) and knowledge of the encoded integrase genes was limited.…”

“…The capacity of phages to completely clear cultures of C. difficile was variable, as previously reported ( 37 , 61 , 67 ), and regrowth of bacteria was observed in all cases where phages were administered individually. At present, it is unclear whether this reflects immunity as a consequence of lysogeny to superinfection by the same phage ( 30 , 68 ) or the development of phage resistance ( 14 ). However, the fact that recovered bacteria were still sensitive to other phages in the cocktail supports the premise that multiple-phage combinations are required for effective clearance.…”

“…The efficacy of phage treatment was assessed in vivo using the Syrian Golden hamster model of acute C. difficile infection. This model reflects many of the clinical features of the disease, including toxin-mediated diarrhea and tissue pathology ( 29 , 30 , 47 ). All procedures were conducted in strict accordance with the Animals Act (Scientific Procedures, 1986) and were approved by the Home Office, United Kingdom (project license number PPL60/4218).…”

“…The reason for this lack of development is largely because C. difficile has not been a target pathogen in the countries where phage therapy is used. Advances in this area have also been limited by the lack of strictly virulent phages that infect this pathogen and by the fact that the isolation of phages for this organism can be challenging, so in some studies, only 1 or 2 C. difficile phages have been isolated and tested ( 29 – 31 ). In species where no lytic phages have been identified, the only pragmatic option for the development of phage therapeutics is to test the efficacy of multiple wild-type phages to determine their efficacy per se and, potentially, to develop the lysogenic phages further using engineering approaches.…”

As Clear as Mud? Determining the Diversity and Prevalence of Prophages in the Draft Genomes of Estuarine Isolates ofClostridium difficile

“…When considering phage use as a potential alternative therapy against C. difficile , it is important to realize the potential inhibition of phage infection through superinfection with related phages ( Govind et al 2011 ). The distribution of prophage types in this data set may explain some of the observations from bacterial host range data using multiple phage panels.…”