Using bacteriophage cocktails in MDR Gram-negative infections: a practical manual

Bacteriophage therapy is a promising treatment on the horizon for multidrug resistant (MDR) and difficult-to-treat infections.

There have been a number of case reports and case series using bacteriophages to treat MDR infections. This has sparked interest by many patients and providers in accessing this treatment. However, the timeline from start of screening for phages to quality control in manufacturing to regulatory applications and the actual administration can be quite long. It is therefore important to be realistic with persons seeking treatment. Bacteriophage therapy is in its infancy. We are only beginning to understand the pharmacokinetics and pharmacodynamics of phages and how the development of phage-specific immune response may impact efficacy. Patients do develop neutralizing antibodies against bacteriophages. This is akin to someone receiving a first-time vaccination or first-time exposure to a viral infection. These neutralizing antibodies have the potential to impede efficacy, particularly if treatment extends past the 14-day window during which a patient first seroconverts from an IgM response to an IgG response. Finally, bacteriophages are useful tools to disrupt biofilms in patients with recurrent urinary tract infections, pulmonary infections, and those with retained hardware.

Understanding the protocol for phage therapy in addition to the potential setbacks is essential to eventually formulating "off-the-shelf" therapy.