Authors: Frances Waller, Future Science Group
Researchers from the Baylor College of Medicine and the Michael E. DeBakey Veteran Affair Medical Center (both TX, USA) have utilized murine models of bacteremia to investigate the effectiveness of phages against multi-drug resistant Escherichia coli ST131. The new study observed that lysis of the E. coli ‘superbugs’ occurred when bacteriophage isolates identified from extraintestinal pathogenic E.coli (ExPEC) reservoirs were utilized.
Bacteriophages, viruses capable of killing bacteria, may assist in overcoming the challenges associated with antibiotic resistance. Anthony Maresso, Baylor College of Medicine, explained the aim of the research was to “find phages that would kill 12 strains of antibiotic-resistant bacteria that were isolated from patients.”
In this latest study, published in Scientific Reports, the ɸHP3 phage demonstrated an ability to significantly improve the health of mice infected with two virulent ExPEC strains. Both E.coli virulence and bacteriophage in vitro lysis ability was proposed to influence efficacy, suggesting phages could present an alternative therapy. Maresso explained: “When the phages are delivered into the animals, their efficacy in reducing the levels of bacteria and improving health is dramatic.”
The advantage of phage therapy over traditional antibiotics hinges around the ability of the phage to evolve as resistance to new drugs arises. Mechanistic action of phage lysis is distinct from that of antibiotics and selective pressure could reverse resistant bacteria to re-acquired sensitivity to antibiotics.
The study explored phage treatment within the context of immunosupression, when patients are at increased risk of ExPEC infection. The research suggests a putative role of phages in treatment of bacterial infection in immunocompromized and high-risk patients.
This research could provide a new insight into therapeutic interventions to treat serious ‘superbug’ infections. Maresso concluded: “There are many ways to kill bacteria, but I know of no other way that has the potential to evolve in real time like phages do. And it’s the best ‘green’ medicine – it’s natural, safe thus far, relatively cheap and can be harnessed with the technical skills of a college biology major.”
Sources: Green SI, Kaelber JT, Ma L et al, Bacteriophages from ExPEC Reservoirs Kill Pandemic Multidrug-Resistant Strains of Clonal Group ST131 in Animal Models of Bacteremia, Sci. Rep., doi:10.1038/srep46151 (2017); www.bcm.edu/news/molecular-virology-and-microbiology/bacteriophages-natural-drugs-combat-superbugs