Three New Escherichia coli Phages from the Human Gut Show Promising Potential for Phage Therapy

Phage therapy targeting Escherichia coli-a story with no end?

Bacteriophages (phages) or bacterial viruses have long been proposed as an alternative therapy against antibiotic-resistant bacteria such as Escherichia coli Even though poorly documented in the scientific literature, a long clinical history of phage therapy in countries such as Russia and Georgia suggests potential value in the use of phages as antibacterial agents. Escherichia coli is responsible for a wide range of diseases, intestinal (diarrhoea) and extraintestinal (UTI, septicaemia, pneumoniae, meningitis), making it an ideal target for phage therapy. This review discusses the latest research focusing on the potential of phage therapy to tackle E. coli-related illnesses. No intact phages are approved in EU or USA for human therapeutic use, but many successful in vitro and in vivo studies have been reported. However, additional research focused on in vivo multispecies models and human trials are required if phage therapy targeting E. coli pathotypes can be a story with happy end.

Fecal microbiota transplantation to fight Clostridium difficile infections and other intestinal diseases

We have analyzed fecal bacterial and viral communities of a patient with recurrent C. difficile infection (rCDI) who was cured by fecal microbiota transplantation (FMT). The "Zürich Patient" experienced immediate cure and has remained free of symptoms for now over 5 y. Donor-similar bacterial compositions after 4.5 y post-FMT demonstrated sustainable engraftment of donor microbiota predominated by Bacteroidetes and Firmicutes bacteria. Appearance of beneficial species Faecalibacterium prausnitzii and Akkermansia municiphila was detected while disease-related Proteobacteria decreased. Stabilization of the microbiota took longer than expected from the rapidly improving clinical symptoms, suggesting the need for longer-lasting patient observation. The virome was mainly composed of Caudovirales bacteriophages but surprisingly also contained sequences related to a Chlorella giant virus that normally infects green algae not known to inhabitate the human intestine. FMT is highly effective against rCDI and is presently broadening its application to other conditions including inflammatory bowel disease (IBD). Here, we discuss the prospects and challenges of FMT against rCDI and other indications including a focus on bacteriophages.

Bacteriophages and its applications: an overview

Bacteriophages (or phages), the most abundant viral entity of the planet, are omni-present in all the ecosystems. On the basis of their unique characteristics and anti-bacterial property, phages are being freshly evaluated taxonomically. Phages replicate inside the host either by lytic or lysogenic mode after infecting and using the cellular machinery of a bacterium. Since their discovery by Twort and d'Herelle in the early 1900s, phage became an important agent for combating pathogenic bacteria in clinical treatments and its related research gained momentum. However, due to recent emergence of bacterial resistance on antibiotics, applications of phage (phage therapy) become an inevitable option of research. Phage particles become popular as a biotechnological tool and treatment of pathogenic bacteria in a range of applied areas. However, there are few concerns over the application of phage-based solutions. This review deals with the updated phage taxonomy (ICTV 2015 Release and subsequent revision) and phage biology and the recent development of its application in the areas of biotechnology, biosensor, therapeutic medicine, food preservation, aquaculture diseases, pollution remediation, and wastewater treatment and issues related with limitations of phage-based remedy.