Phage Therapy

Here, we present the complete genome sequence of Enterobacter phage vB_EcRAM-01, isolated from waters of the Río Abajo river, in Panama City, Panama. This phage has deployed lytic activity against the Enterobacter cloacae complex, a pathogen of clinical importance in intensive care units. It belongs to the Myoviridae family and has a double-stranded DNA genome that is 178,477 bp long and contains 293 open reading frames (ORFs).

Recently, a Typhi isolate producing CTX-M-15 extended spectrum β-lactamase (ESBL) and with decreased ciprofloxacin susceptibility was isolated in the Democratic Republic of the Congo. We have selected bacteriophages that show strong lytic activity against this isolate and have potential for phage-based treatment of . Typhi, and in general.

Summary The hypothesis as to whether a benign species of bacteria could kill a virulent kind has to this point been untested. Recently it was shown that in the macrophage, bacteriophages, when properly introduced through a nonvirulent
microbe, had a killing rate for virulent AIDS Mycobacterium tuberculosis and Mycobacterium avium far in excess of modern day antibiotics. The study in effect brought a natural phenomena, lysogeny, whereby one bacterial colony kills another thru phage weaponry, to bear in the conquest of hard-to-kill, antibiotic resistant pathogens. This killing occurred intracellularly, within the white blood cell using Mycobacterium smegmatis, a benign bacterial species found generally in smegma secretions from human genitalia as well as soil, dust and water, and first identified
in 1884. The subsequent treatment of M. avium-infected, as well as M. tuberculosis-infected RAW 264.7 macrophages, with M. smegmatis transiently infected with TM4 resulted in a unexpectedly large time- and titer-dependent reduction in the number of viable intracellular bacilli. In addition, the M. smegmatis vacuole harboring TM4 fused with the M. avium vacuole in macrophages. These results suggested a potentially novel concept to kill intracellular pathogenic bacteria and warrant future
development.

The emergence of multiple drug-resistant bacteria has prompted interest in alternatives to conventional antimicrobials. One of the possible replacement options for antibiotics is the use of bacteriophages as antimicrobial agents. Phage therapy is an important alternative to antibiotics in the current era of drug-resistant pathogens. Bacteriophages have played an important role in the expansion of molecular biology and have been used as antibacterial agents since 1966. In this review, we describe a brief history of bacteriophages and clinical studies on their use in bacterial disease prophylaxis and therapy. We discuss the advantages and disadvantages of bacteriophages as therapeutic agents in this regard.

Felix d’Herelle proposed the use of bacteriophages for the therapy
of human and animal bacterial infections at the beginning of the
20th century. This approach, however, was not widely accepted in
the West. After the emergence of antibiotics in 1940s, phage
research was diverted to a more fundamental level. At the same
time, phage therapy was widely practiced in the Soviet Union
due to collaboration of Felix d’Herelle with his Georgian colleagues.
The majority of the articles dedicated to this subject are from the
1930s and 1940s. The old Soviet literature indicates that phage ther-
apy was used extensively to treat a wide range of bacterial infections
in the areas of dermatology (Beridze, 1938), ophthalmology (Rodigina,
1938), urology (Tsulukidze, 1938), stomatology (Ruchko and Tretyak,
1936), pediatrics (Alexandrova et al., 1935; Lurie, 1938), otolaryngology
(Ermolieva, 1939), and surgery (Tsulukidze, 1940, 1941). These articles
were published in Russian and thus were not readily available to
Western scientists. The Western skepticism toward phage therapy
itself was again followed by renewed interest and reappraisal, mainly
due to the emergence of drug-resistant bacteria. Often the experi-
ments described in the old Soviet articles were not designed prop-
erly: the use of placebos and the coding of preparations were absent
from most of the studies, number of patients in the experimental and
control groups was unequal or missing, sometimes no control groups
were used at all, or patients treated previously unsuccessfully with
antibiotics were employed as an experimental group and as control.
The results obtained and the efficiency of phage prophylaxis were
estimated by comparing with results obtained in previous years. In
most publications, phage titers and descriptions of methods used for
evaluation of the results are not specified. Nevertheless, past experi-
ence indicates some effectiveness of phage therapy and prophylaxis.
Therefore, these clinical results should not be neglected when
designing any future studies.

Mycobacterium avium causes disseminated infection in patients with acquired immune deficieny syndrome. Mycobacterium tuberculosis is a pathogen associated with the deaths of millions of people worldwide annually. Effective therapeutic regimens exist that are limited by the emergence of drug resistance and the inability of antibiotics to kill dormant organisms. The present study describes a system using Mycobacterium smegmatis, an avirulent mycobacterium, to deliver the lytic phage TM4 where both M. avium and M. tuberculosis reside within macrophages. These results showed that treatment of M. avium–infected, as well as M. tuberculosis–infected, RAW 264.7 macrophages, with M. smegmatis transiently infected with TM4, resulted in a significant time- and titer-dependent reduction in the number of viable intracellular bacilli. In addition, the M. smegmatis vacuole harboring TM4 fuses with the M. avium vacuole in macrophages. These results suggest a potentially novel concept to kill intracellular
pathogenic bacteria and warrant future development.

Dès 1917, dans l'article où il décrit ses premières observations et propose le nom de bactériophage, Félix d'Hérelle rapporte une première utilisation de ces virus pour traiter des infections bactériennes, donnant ainsi naissance à la pha-gothérapie. Le développement de cette application a montré qu'il était possible de mettre en place des traitements ciblant spécifiquement les bactéries, tels que ceux basés sur l'utilisation d'antibiotiques. Ces derniers, de par leur très grande effica-cité et simplicité d'utilisation, ont provoqué le quasi-abandon de la phagothérapie. Aujourd'hui, un nombre croissant de bactéries pathogènes pour l'homme présente des phénotypes de résistance à plusieurs familles d'antibiotiques. Les infections causées par ces bactéries imposent l'utilisation de molécules au spectre d'activité toujours plus large et placent certains patients en situation d'impasse thérapeu-tique. Cet état de fait a relancé les recherches pour permettre le déploiement de la phagothérapie afin de traiter des patients mais aussi des animaux et des plantes. En fait, les domaines d'applications thérapeutiques des bactériophages s'élargissent au fur et à mesure que les agents antibactériens de nature chimique sont remis en cause, voire interdits. Cette revue revient sur les principes fondamentaux des applications thérapeutiques des bactériophages et expose les données récentes dans les domaines pour lesquels une exploitation commerciale est en cours ou sur le point d'émerger.

Abstract. In the 1917 article in which Félix d'Hérelle describes his first observations and proposes the name of bacteriophage, he also reports the first use of these viruses to treat bacterial infections, thus giving birth to phage therapy. Soon after antibiotics supplanted bacteriophages. Today, bacteria resistant to multiple antibiotics become a growing public health issue worldwide. This situation has revived research aiming at developing the antibacterial activity of bacteriophages to treat patients as well as diseases in animals and plants. In fact, the areas of applications of bacteriophages as antibacterial are widening as current solutions of chemical nature are questioned. This review summarizes the basic principles of therapeutic applications of bacteriophages and presents recent data in areas where commercial exploitation is occurring or about to emerge.

Phage therapy is a microbial based therapy that utilizes the lytic life cycle of bacteriophage to treat pathogenic bacterial infections. It is the earliest antibacterial therapy in modern history. The early success of phage therapy lost its luster after the development of the less controversial antibiotic chemotherapies. However, in the context of the advanced microbiology and biotechnology, phage therapy is reviving as an alternative for antibiotics chemotherapy, especially against multidrug resistant (MDR) bacterial infections [1-3].

Bacterial diseases have serious impacts on agricultural food production. Several methods are available to control these phytopathogens, including antibiotics and copper sprays. However, bacterial resistance to antibiotics makes it risky to continue those strategies and highlights the need for effective disease-control agents. An alternative option is the use of lytic phages to control phytopathogens. Phages are in vivo anti-phytopathogenic isolates that can be used for in vitro biocontrol. In some circumstances, increased phage disease-control efficiency, protective formulations, appropriate application timings, and integrated management strategies can be achieved. The use of phages in plant disease control is a compelling topic, and several successful studies have been done on phytopathogens. In this chapter, we explore the use of phages in plant-disease control and their roles in the development of effective biocontrol agents.

Bacteriophages, or viruses of microbes, when used as a medical strategy, might be able to solve the current crisis mankind faces with the increasing number of pathogens being antibiotic-resistant, where chemical drugs seized to show any therapeutic effect. The so-called phage therapy may be one of the most promising alternatives to treat infections caused by antibiotic-resistant bacteria, which are killed after infection by a phage. While phages that destroy the host by lysis are chosen for therapy, many pharmacological and immunological aspects of phages as medicines have not been established so far. The immune system plays an important role in a process called phage acceptance where both, innate and adaptive immune responses of the host are involved. However, not only medical aspects but also social ones such as lacking public awareness or acceptance, and lack of structured regulatory guidelines are challenges that have to be addressed in the near future to establish phage therapy as a reliable and safe alternative for the treatment of infections. This review focuses on the unique pharmacological and immunological aspects of phages used in therapy.

Bacteriophages, or simply phages, are the most abundant biological entities on Earth. One of the most interesting characteristics of these viruses, which infect and use bacteria as their host organisms, is their high level of specificity. Since their discovery, phages became a tool for the comprehension of basic molecular biology and originated applications in a variety of areas such as agriculture, biotechnology, food safety, veterinary, pollution remediation and wastewater treatment. In particular, phages offer a solution to one of the major problems in public health nowadays, i.e. the emergence of multidrug-resistant bacteria. In these situations, the use of virulent phages as therapeutic agents offers an alternative to the classic, antibiotic–based strategies. The development of phage therapies should be accompanied by the improvement of phage biomanufacturing processes, both at laboratory and industrial scales. In this review, we first present some historical and general aspects related with the discovery, usage and biology of phages and provide a brief overview of the most relevant phage therapy applications. Then, we showcase current processes used for the production and purification of phages and future alternatives in development. On the production side, key factors such as the bacterial physiological state, the conditions of phage infection and the operation parameters are described alongside with the different operation modes, from batch to semi-continuous and continuous. Traditional purification methods used in the initial phage isolation steps are then described followed by the presentation of current state-of-the-art purification approaches. Continuous purification of phages is finally presented as a future biomanufacturing trend.

Background and Aim: This study aimed to isolate phages able to lyse some strains of multiple drug-resistant (MDR)-Klebsiella pneumoniae (named vB_Kp1 and vB_Kp2) and Enterobacter aerogenes (named vB_Ea1) from swage.
Materials and Methods: Different K. pneumoniae and E. aerogenes strains were isolated from clinical specimens during January-September 2018 in three hospitals of Amol, Mazandaran, Iran. Kirby-Bauer disc diffusion method was used to determine the resistance profiles of these isolates using different antibiotics. The MDR strains were selected for investigating the effect of isolated phages from wastewater and hospital sewage. The presence of phage was confirmed by plaque formation. The isolated bacteriophages were enriched, concentrated, and stained. Afterwards, a transmitting electron microscope (TEM) was applied to observe the morphology of the bacteriophages. Phage identification tests, including host range and one-step growth, were performed.
Results: The TEM analysis revealed that three phages had an icosahedral capsid and long contractile tail being classified as a member of the Myoviridae family. Phages were able to lyse 14 (56%) of the 25 MDR isolated bacterial strains. The one-step growth curve showed large bursts and short latent times.
Conclusion: The formation of clear plaques demonstrates the high lyse power of phages. Therefore, they have good potential for further analysis for clinical use as a therapeutic agent in the future.

Researchers increasingly believe that microbial, molecular and synthetic biology techniques along with genetic engineering will facilitate the treatment of persistent infectious diseases. However, such therapy has been plagued by the emergence of antibiotic-resistant bacteria, resulting in significant obstacles to treatment. Phage therapy is one promising alternative to antibiotics, especially now that recent modifications to ubiquitous phages have made them more controllable. Additionally, convincing in vitro and in vivo studies of genetically modified lytic phages and engineered non-lytic phages have confirmed the advantages of novel, specific bactericidal agents over antibiotics in some cases. There is still a need for a better understanding of phage therapy, however, before it can be adopted widely.

Phage therapy, the use of bacteriophage viruses to treat bacterial infections, has existed for more than a hundred years. However, the practice is struggling to develop, despite growing support over the past 15 years from researchers and doctors, who see it as a promising therapy in the context of the rise of antimicrobial resistance (AMR). While the reasons for these developmental difficulties are complex, in this article we wish to address the effects of pharmaceutical regulations on phage therapy. By showing how phages are assimilated to an umpteenth antibiotic in legal texts, but also in certain medical practices, this article proposes to analyze the consequences of such regulatory categorization both for their production and the logistics of administration of proof of their efficacy in randomized controlled trials (RCTs), as well as the underlying concepts of infection and treatment. This paper follows Chandler’s work on the concept of antibiotics as infrastructure and its inversion presented by antimicrobial resistance. Phages as living, dynamic, evolving, and specific entities, do not lend themselves easily to current categories, norms, and development models. In this sense, they act as disruptors, revealing the limitations imposed by the existing infrastructure. More precisely here, and to continue Chandler’s initial thought process, this paper aims to show that antibiotics also form a kind of epistemological infrastructure, which acts as a powerful inhibitor to the development of phage therapy. In this sense antibiotics prevent the development of solutions to the problem they contribute to create. But the difficulties phage therapy faces, as highlighted in this article, can be interpreted as entry points for thinking of another medicine and imagining other possible futures. This analysis is based on a 3-year fieldwork study (2016–2019) in Europe (France, Belgium, and Switzerland), during which we conducted semi-directed interviews with various phage therapy stakeholders (physicians, researchers, pharmacists, regulators, patients, and patient associations), participatory observation in labs and observations during symposia and workshops on phages and phage therapy.

The emergence of antibiotic-resistant bacteria and decrease in the discovery rate of novel antibiotics takes mankind back to the ‘pre-antibiotic era' and search for alternative treatments. Bacteriophages have been one of promising alternative agents which can be utilised for medicinal and biological control purposes in agriculture and related fields. The idea to treat bacterial infections with phages came out of the pioneering work of Félix d‘Hérelle but this was overshadowed by the success of antibiotics. Recent renewed interest in phage therapy is dictated by its advantages most importantly by their specificity against the bacterial targets. This prevents complications such as antibiotic-induced dysbiosis and secondary infections. This article is compiled by the participants of the Expert Round Table conference ‘Bacteriophages as tools for therapy, prophylaxis and diagnostics' (19–21 October 2015) at the Eliava Institute of Bacteriophage, Microbiology and Virology, Tbilisi...

Aims: To identify enzymes associated with bacteriophages infecting cystic fibrosis
(CF) strains of Pseudomonas aeruginosa that are able to degrade extracellular
alginic acids elaborated by the host bacterium.
Methods and Results: Plaques produced by 21 Ps. aeruginosa-specific phages
were screened for the presence of haloes, an indicator of capsule hydrolytic
activity. Four phages produced haloed plaques, and one (PT-6) was investigated
further. PT-6 was shown by electron microscopy to belong to Podoviridae
family C1, to reduce the viscosity of four alginate preparations using a
rolling ball viscometer and to release uronic acid-containing fragments from
the polymers, as judged by spectrophotometry and thin layer chromatography.
The alginase was partially purified by gel filtration chromatography and shown
to be a 37 kDa polypeptide.
Conclusions: Infection of CF strains of Ps. aeruginosa by phage PT-6 involves
hydrolysis of the exopolysaccharide secreted by the host.
Significance and Impact of the Study: The alginase produced by PT-6 has the
potential to increase the well-being of CF suffers by improving the surface
properties of sputum, accelerating phagocytic uptake of bacteria and perturbing
bacterial growth in biofilms.

Therapeutic bacteriophages, commonly called as phages, are a promising potential alternative to antibiotics in the management of bacterial infections of a wide range of organisms including cultured fish. Their natural immunogenicity often induces the modulation of a variated collection of immune responses within several types of immunocytes while promoting specific mechanisms of bacterial clearance. However, to achieve standardized treatments at the practical level and avoid possible side effects in cultivated fish, several improvements in the understanding of their biology and the associated genomes are required. Interestingly, a particular feature with therapeutic potential among all phages is the production of lytic enzymes. The use of such enzymes against human and livestock pathogens has already provided in vitro and in vivo promissory results. So far, the best-understood phages utilized to fight against either Gram-negative or Gram-positive bacterial species in fish culture ar...

Water quality is largely influenced by the abundance and diversity of indigenous microbes present within an aquatic environment. Physical, chemical and biological contaminants from anthropogenic activities can accumulate in aquatic systems causing detrimental ecological consequences. Approaches exploiting microbial processes are now being utilized for the detection, and removal or reduction of contaminants. Contaminants can be identified and quantified in situ using microbial whole-cell biosensors, negating the need for water samples to be tested off-site. Similarly, the innate biodegradative processes can be enhanced through manipulation of the composition and/or function of the indigenous microbial communities present within the contaminated environments. Biological contaminants, such as detrimental/pathogenic bacteria, can be specifically targeted and reduced in number using bacteriophages. This mini-review discusses the potential application of whole-cell microbial biosensors for the detection of contaminants, the exploitation of microbial biodegradative processes for environmental restoration and the manipulation of microbial communities using phages.

Phage therapy is increasingly put forward as a "new" potential tool in the fight against antibiotic resistant infections. During the "Centennial Celebration of Bacteriophage Research" conference in Tbilisi, Georgia on 26-29 June 2017, an international group of phage researchers committed to elaborate an expert opinion on three contentious phage therapy related issues that are hampering clinical progress in the field of phage therapy. This paper explores and discusses bacterial phage resistance, phage training and the presence of prophages in bacterial production strains while reviewing relevant research findings and experiences. Our purpose is to inform phage therapy stakeholders such as policy makers, officials of the competent authorities for medicines, phage researchers and phage producers, and members of the pharmaceutical industry. This brief also points out potential avenues for future phage therapy research and development as it specifically addresses thos...

For over a century, scientists have run experiments using phage viruses to treat bacterial infections. Until recently, the results were inconclusive because the mechanisms viruses use to attack bacteria were poorly understood. With the development of molecular biology, scientists now have a better sense of how phage work, and how they can be used to target infections. As resistance to traditional antibiotics continues to spread around the world, there is a moral imperative to facilitate research into phage therapy as an alternative treatment. This essay reviews ethical questions raised by phage therapy, and discusses regulatory challenges associated with phage research, and phage treatments.

Through recent decades, the subtherapeutic use of antibiotics within agriculture has
led to the widespread development of antimicrobial resistance. This problem not only impacts
the productivity and sustainability of current agriculture but also has the potential to transfer
antimicrobial resistance to human pathogens via the food supply chain. An increasingly popular
alternative to antibiotics is bacteriophages to control bacterial diseases. Their unique bactericidal
properties make them an ideal alternative to antibiotics, as many countries begin to restrict the usage
of antibiotics in agriculture. This review analyses recent evidence from within the past decade on
the efficacy of phage therapy on common foodborne pathogens, namely, Escherica coli, Staphylococcus
aureus, Salmonella spp., and Campylobacter jejuni. This paper highlights the benefits and challenges
of phage therapy and reveals the potential for phages to control bacterial populations both in food
processing and livestock and the possibility for phages to replace subtherapeutic usage of antibiotics
in the agriculture sector.

Rémy Froissart, Charlotte Brives, Cécile Breyton, Claire Le Marrec

The present meeting report aims to cover the scientific activities of the 4th French Bacteriophage Network (Phages.fr) symposium which took place during 24th-25th September 2018, at the Agora du Haut-Carré in Talence (France). The hosting institute was University Bordeaux and 72 participants attended the meeting from both public and private sectors, coming from France, Belgium, Ireland, Germany, Portugal and Canada. The scientific program was structured in three themed oral sessions entitled "ecology and evolution", "bacteriophage-host molecular interaction", and "therapy and biotechnology applications" consisting of 21 oral presentations, including three keynote lectures, and a presentation of the activities of the Spanish bacteriophage network. A poster session included 22 presentations.

Background: Phage therapy is the therapeutic use of bacteriophages to treat highly drug resistant bacterial infections. The current surge in bacteriophage therapy is motivated mainly because of the emergence of antibiotic-resistant bacteria in clinics. This study evaluated the therapeutic potential of three bacteriophages isolated against Escherichia coli ec311, Klebsiella pneumoniae kp235 and Enterobacter cloacae el140 strains using Galleria mellonella. The in vitro activity of three different phages belonging to Podoviridae and Myoviridae families was studied by the double agar overlay method against multi-drug resistant strains. Larval survivability studies were performed to evaluate the potential of phages against infection using G. mellonella. Results: All the three phages were found to have potential to infect the host bacterial strains. For in vivo studies it was observed that E. coli and E. cloacae infected larvae, should be treated with three phage doses (20 μL, 10 4 PFU/mL) at 6 h interval to achieve 100% survival rate. But in the case of K. pneumoniae, a single phage dose treatment showed promising outcome. When mixed bacterial infections (all three bacterial cultures at 10 8 CFU/mL) were tested, minimum of four doses of phage cocktail (three phages) at 6 h interval was necessary to recover the larvae. All the results were confirmed by enumerating bacteria from the larvae. Conclusion: Our data shows that although in vitro studies showed high infectivity of phages, for in vivo models multiple phage doses were required for effective treatment.

Pseudomonas aeruginosa is an ubiquitous organism which has emerged as a major threat in the hospital environment. Overuse of antibiotics has also significantly increased the emergence of antimicrobial multiresistant bacteria. P. aeruginosa has an innate ability to adhere to surfaces and form virulent biofilms. Bacteriophage might represent one attractive solution to this problem. In this study, P.aeruginosa phage were utilized to Biofilm inhibition and remove.Sample collected from University sewage. Isolation was done according to Martha.R.J.Clokie protocol. Serial dilution prepared, then equally incubated with bacteria to investigate Biofilm inhibition potential. Biofilm formed base on Microplate Biofilm Assay. The effect of isolated phage investigated on biofilm remove of Pseudomonas putida, E.coli and Acinetobacter baumanii. P.aeruginosa biofilm had OD: 1.688 in 492n.m. Pure phage, 10-2 and 10-3 diluted phage decreased OD to 1.587, 1.341 and 1.461, respectively. Isolated phage dramatically decline OD of Biofilm of all strains.Phages have various affinity to attach to hosts, thereby it is supposed to phages compete for their receptors. Therefore it is supposed phages have most efficiency in optimum concentration to remove biofilm or growth inhibition.

The application of bacteriophages as antibacterial agents has many benefits in the “post-antibiotic age”. To increase the number of successfully targeted bacterial strains, phage cocktails, instead of a single phage, are commonly formulated. Nevertheless, there is currently no consensus pipeline for phage cocktail development. Thus, although large cocktails increase the spectrum of activity, they could produce side effects such as the mobilization of virulence or antibiotic resistance genes. On the other hand, coinfection (simultaneous infection of one host cell by several phages) might reduce the potential for bacteria to evolve phage resistance, but some antagonistic interactions amongst phages might be detrimental for the outcome of phage cocktail application. With this in mind, we introduce here a new method, which considers the host range and each individual phage-host interaction, to design the phage mixtures that best suppress the target bacteria while minimizing the number o...

Widespread antibiotic use in clinical medicine and the livestock industry has contributed to the global spread of multidrug-resistant (MDR) bacterial pathogens, including Acinetobacter baumannii. We report on a method used to produce a personalized bacteriophage-based therapeutic treatment for a 68-year-old diabetic patient with necrotizing pancreatitis complicated by an MDR A. baumannii infection. Despite multiple antibiotic courses and efforts at percutaneous drainage of a pancreatic pseudocyst, the patient deteriorated over a 4-month period. In the absence of effective antibiotics, two laboratories identified nine different bacteriophages with lytic activity for an A. baumannii isolate from the patient. Administration of these bacteriophages intravenously and percutaneously into the abscess cavities was associated with reversal of the patient’s downward clinical trajectory, clearance of the A. baumannii infection, and a return to health. The outcome of this case suggests that the...

Phage therapy is increasingly put forward as a "new" potential tool in the fight against antibiotic resistant infections. During the "Centennial Celebration of Bacteriophage Research" conference in Tbilisi, Georgia on 26-29 June 2017, an international group of phage researchers committed to elaborate an expert opinion on three contentious phage therapy related issues that are hampering clinical progress in the field of phage therapy. This paper explores and discusses bacterial phage resistance, phage training and the presence of prophages in bacterial production strains while reviewing relevant research findings and experiences. Our purpose is to inform phage therapy stakeholders such as policy makers, officials of the competent authorities for medicines, phage researchers and phage producers, and members of the pharmaceutical industry. This brief also points out potential avenues for future phage therapy research and development as it specifically addresses thos...

Against a backdrop of global antibiotic resistance and increasing awareness of the importance of the human microbiota, there has been resurgent interest in the potential use of bacteriophages for therapeutic purposes, known as phage therapy. A number of phage therapy phase I and II clinical trials have concluded, and shown phages don't present significant adverse safety concerns. These clinical trials used simple phage suspensions without any formulation and phage stability was of secondary concern. Phages have a limited stability in solution, and undergo a significant drop in phage titre during processing and storage which is unacceptable if phages are to become regulated pharmaceuticals, where stable dosage and well defined pharmacokinetics and pharmacodynamics are de rigueur. Animal studies have shown that the efficacy of phage therapy outcomes depend on the phage concentration (i.e. the dose) delivered at the site of infection, and their ability to target and kill bacteria, ...

This paper is the translation of an article published in French in the Revue d'Anthropologie des Connaissances, "Evolutions et involutions dans la biomédecine, thérapie phagique et traitement des infections bactériennes antibiorésistantes ", 15(3). https://journals.openedition.org/rac/24239 Evolutions and involutions in biomedicine. Phage therapy and treatment of antibiotic-resistant bacterial infections

Starting from phage therapy, the therapeutic use of bacteriophage viruses to treat bacterial infections, this paper shows, by describing bacteriophage collection practices, how the assignment by scientists of a name to a viral strain actually corresponds to a snapshot, at a given time, of a microgeohistory, of an ever-dynamic and fluctuating relationship between bacteriophages and bacteria and their given environments. For scientists engaged in this task, putting phages in a collection does not conduct, at any point of the process, to essentialization. Rather, it is a way to engage with pluribiosis, with the recognition of the existence of multiple relational spectrums between entities forever in the process of becoming, constantly shaped and transformed by their interactions with other living things. Pluribiosis then allows to envisage, with the actors of phage therapy, other ways of treating and practicing infectiology, and other development models.

Sequencing and annotation was performed for two large double stranded DNA bacteriophages, ϕGrn1 and ϕSt2 of the Myoviridae family, considered to be of great interest for phage therapy against Vibrios in aquaculture live feeds. In addition, phage–host metabolic interactions and exploitation was studied by transcript profiling of selected viral and host genes. Comparative genomic analysis with other large Vibrio phages was also performed to establish the presence and location of homing endonucleases highlighting distinct features for both phages. Phylogenetic analysis revealed that they belong to the " schizoT4like " clade. Although many reports of newly sequenced viruses have provided a large set of information, basic research related to the shift of the bacterial metabolism during infection remains stagnant. The function of many viral protein products in the process of infection is still unknown. Genome annotation identified the presence of several viral open reading frames (ORFs) participating in metabolism, including a Sir2/cobB (sirtuin) protein and a number of genes involved in auxiliary NAD + and nucleotide biosynthesis, necessary for phage DNA replication. Key genes were subsequently selected for detail study of their expression levels during infection. This work suggests a complex metabolic interaction and exploitation of the host metabolic pathways and biochemical processes, including a possible post-translational protein modification, by the virus during infection.

A novel bacteriophage, vB_KpnP_KpV289,
lytic for hypermucoviscous strains of Klebsiella pneumoniae,
was attributed to the family Podoviridae, subfamily
Autographivirinae, genus T7likevirus based on transmission
electron microscopy and genome analysis. The complete
genome of the bacteriophage vB_KpnP_KpV289
consists of a linear double-stranded DNA of 41,054 bp
including 179-bp direct-repeat sequences at the ends and
51 open reading frames (ORFs). The G?C content is
52.56 %. The phage was shown to lyse 15 out of 140
(10.7 %) K. pneumoniae strains belonged to the capsular
types K-1, K-2, and K-57 and strains without a determined
capsular type, including a hypermucoviscous strain of the
novel sequence type ST-1554.

Biofilm mediated protection of pathogens from environmental stresses are recognized as one of the major threat worldwide, which encourage the
researcher to search for other alternative approach. Bacteriophage therapy is one such effective and controlled strategy that undertakes the utilization
of tailored phage mediated biofilm inhibition. Hence, in this study, P2 phage, specific to Pseudomonas aeruginosa PA01 was isolated and its potential
to inhibit biofilm formation was studied. Important findings are summarized in the manuscript.

Phage therapy (PT) is a unique method of treatment of bacterial infections using bacteriophages (phages)-viruses that specifically kill bacteria, including their antibiotic-resistant strains. Over the last decade a marked increase in interest in the therapeutic use of phages has been observed, which has resulted from a substantial rise in the prevalence of antibiotic resistance of bacteria, coupled with an inadequate number of new antibiotics. The first, and so far the only, center of PT in the European Union is the Phage Therapy Unit (PTU) established at the Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Wrocław, Poland in 2005. This center continues the rich tradition of PT in Poland, which dates from the early 1920s. The main objective of this chapter is to present a detailed retrospective analysis of the results of PT of 153 patients with a wide range of infections resistant to antibiotic therapy admitted for treatment at the PTU between January 2008 and December 2010. Analysis includes the evaluation of both the efficacy and the safety of PT. In general, data suggest that PT can provide good clinical results in a significant cohort of patients with otherwise untreatable chronic bacterial infections and is essentially well tolerated. In addition, the whole complex procedure employed to obtain and characterize therapeutic phage preparations, as well as ethical aspects of PT, is discussed.

Emergence of drug resistance has rekindled the interest in phage therapy as an alternative treatment option. Its potency, safety and proven efficacy is worth noting. However, phage therapy still suffers from issues of poor stability, narrow spectrum and poor pharmacokinetic profile. It therefore becomes essential to look into the use of Drug Delivery Systems (DDS) for efficient delivery of lytic phages in vivo For the first time, the present study has evaluated the use of nano-structured lipid based carriers i.e. Transfersomes as transdermal delivery systems for encapsulating MRSA phage cocktail. Further, therapeutic potential of the encapsulated phage cocktail has been studied in resolving experimental soft tissue infection in rats. Results from in vitro stability as well as in vivo phage titer experiments indicate that transfersome entrapped phage cocktail showed better persistence and stability than free phages. Besides this, rats administered with transfersome entrapped phage co...