Our greatest glory is not in never falling, but in rising every time we fall.
Confucius
The overuse of antibiotics has created a threatening situation for public health. The number of patients coming to clinics with drug resistant bacteria is dramatically increasing, leaving doctors very concerned. In Europe and the USA alone, at least 50,000 annual deaths are attributed to antimicrobial resistance1-2. In 2016, the spreading of a pan-drug resistant bacterium was first described3. If alternative treatment options are not developed soon, a dystopian post-antibiotic era might become the future. In addition to thousands of deaths, antimicrobial resistance causes significant economic burden, as chronic infections require expensive treatments4.
Current Methods to treat Bacterial Infections
Commonly, physicians treat bacterial infections by prescribing broad-spectrum antibiotics. The advantage of these antibiotics is that they target a wide range of bacterial species, leading to recovery without the need for further diagnostics. However, in serious infection cases identification of the pathogen and assessment of antimicrobial susceptibility is simultaneously performed. In case the bacteria causing the infection harbor resistances, treatment is adjusted accordingly. For this assessment, many hospitals maintain highly automated diagnostic laboratories. We visited one of these laboratories at our local hospital to get an overview of the procedure. We found out, that through employing modern molecular biological techniques, precise diagnosis of the pathogen and its resistances commonly requires less than 24 hours5-6.
In contrast to broad-spectrum antibiotics, bacteriophages are highly specific. As a result, exact diagnosis is mandatory. While this might be a drawback for the initial treatment phase, as soon as the pathogen is identified, the high specificity is a great advantage. Conventional antibiotics are known to affect the human microbiome in a dramatic way, leading to a huge variety of side effects that prevail long after the treatment, above all, favoring Clostridium difficile infections7. This is where phages are advantageous, with no severe side effects known to date8.
The specificity issue of phage therapy could be overcome by establishing a large phage database and applying several phages simultaneously. Prediction powers of in vitro experiments for in vivo efficacy of the phages appears to be sufficient in most cases9.
Phage therapy is widely used in Georgia, Russia and Poland, and was recently approved in Belgium, France and the Netherlands10. We met phage therapy practitioners from the Eliava Institute, Georgia as well as experts from Queen Astrid Military Hospital, Belgium and Institut Pasteur, France to find out about current methods of phage production.
We learned that for generating phages, cultivation of live host bacteria is strictly required. Bacterial lysis induced by addition of organic solvents or lysozyme leads to release of the phages, followed by extensive purification steps to remove immunogenic bacterial components11.
The production of phages with this method leads to a high risk for contamination with live pathogenic bacteria. In addition, the host bacteria used for production might contain prophages, posing another contamination risk. Prophages are latent temperate phages, incorporated in the genome of the host bacterium. Exposure of the bacteria to chemicals leads to prophage induction. When the temperate phages leave their host, they might be included in the preparation. Some temperate phages are able to boost the virulence of dangerous pathogens via horizontal gene transfer12.
To eliminate these contamination risks, expensive and time-consuming steps have to be incorporated into phage production. The bacteriophages that can be used for therapy are limited by the capability to produce them in a characterized and prophage-free host. In addition to safety concerns, current phage production is highly inefficient.
Phactory Solves Manufacturing
Phactory is the ultimate solution to these problems, enabling production in a single characterized and safe system, complemented by a quality control structure. Through using a cell-free system, any phage can be produced on the basis of a DNA or RNA template, which can be assessed for purity with the software Sequ-Into.
Cell-free phage production is a disruptive innovation. With this new method, legislative approval is no longer required for every individual phage preparation. Instead, it is presumable that newly established regulatory framework only requires compliance with a defined manufacturing process. First policies of this kind have been implemented in early 2018 in Belgium, France and the Netherlands, with many countries likely to follow13.
Compared to conventional phage production, our method is far more efficient. A therapeutic dose of phages requires a volume of only 20 μl Upscaling and process streamlining minimize personnel expenditures and reduce manufacturing cost to less than one dollar per dose.
Impact on Lives
Phactory is a cure for multi-drug resistant bacterial infections
As Phactory boosts phage therapy, it can significantly reduce the burden of antimicrobial resistance. We demonstrated clinical relevance by manufacturing a phage specific to the enterohemorrhagic E. coli (EHEC) strain O104:H4. An outbreak of this pathogen in Germany and France affected more than 3000 people and caused 42 deaths in 201114. Reflecting upon this crisis, we thought about a method for oral administration of our produced phages. As a low pH and the presence of proteolytic enzymes in the stomach significantly reduce the titer of functional phages, we decided to implement packaging protocols in our project. Phactory therefore includes a microfluidic hardware for calcium-alginate encapsulation, which was shown to enable intestinal delivery15.
Phactory is a product for healthcare professionals and not a general public
The simple and universal applicability of Phactory creates a small, but not negligible risk for misuse. Cell-free systems pose a risk when combined with a DNA sequence encoding for dangerous biological agents. The danger of misuse is however not higher than that of other lab equipment.
Our product is exclusively designed for professional users such as pharmacists, scientists and doctors. Phactory allows point-of-care use but should not be distributed to a general public.
Phage therapy should be prescribed by doctors
We engaged with the public in the form of a questionnaire to figure out the opinion of layman on phage therapy. We were surprised that only few people were actually aware of phage therapy as an alternative to conventional antibiotics. In addition, people stated that they would trust new therapy options most if doctors were to recommend them. We therefore think that physicians and pharmacists are the target audience.
References
- Centers for Disease Control and Prevention, 2017. Antibiotic/Antimicrobial Resistance.
- ECDC Data and reports: Antimicrobial resistance and consumption, 2017
- Liu, Y.-Y. et al. Emergence of plasmid-mediated colistin resistance mechanism MCR-1 in animals and human beings in China: a microbiological and molecular biological study. Lancet Infect. Dis. 16, 161–168 (2016).
- Barriere, S. L. Clinical, economic and societal impact of antibiotic resistance. Expert Opin. Pharmacother. 16, 151–153 (2015).
- Dierig, A., Frei, R. & Egli, A. The fast route to microbe identification: matrix assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS). Pediatr. Infect. Dis. J. 34, 97–9 (2015).
- Ng, E. W. Y., Wong, M. Y. M. & Poon, T. C. W. in 139–175 (Springer, Berlin, Heidelberg, 2013).
- Theriot, C. M. et al. Antibiotic-induced shifts in the mouse gut microbiome and metabolome increase susceptibility to Clostridium difficile infection. Nat. Commun. 5, 3114 (2014).
- Międzybrodzki, R. et al. Clinical Aspects of Phage Therapy. Adv. Virus Res. 83, 73–121 (2012).
- Henry, M., Lavigne, R. & Debarbieux, L. Predicting in vivo efficacy of therapeutic bacteriophages used to treat pulmonary infections. Antimicrob. Agents Chemother. 57, 5961–8 (2013).
- Pirnay, J.-P. et al. The Magistral Phage. Viruses 10, 64 (2018).
- Gill, J., & Hyman, P. (2010). Phage Choice, Isolation, and Preparation for Phage Therapy. Current Pharmaceutical Biotechnology, 11(1), 2–14.
- Fortier, L.-C. & Sekulovic, O. Importance of prophages to evolution and virulence of bacterial pathogens. Virulence 4, 354–365 (2013).
- Fauconnier, A. in 253–268 (Humana Press, New York, NY, 2018). doi:10.1007/978-1-4939-7395-8_19
- Navarro-Garcia, F. Escherichia coli O104:H4 Pathogenesis: an Enteroaggregative E. coli/Shiga Toxin-Producing E. coli Explosive Cocktail of High Virulence. Microbiol. Spectr. 2, (2014).
- Colom, J. et al. Microencapsulation with alginate/CaCO3: A strategy for improved phage therapy. Sci. Rep. 7, 41441 (2017).