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Background: Infections are a major cause of morbidity in burn patients. We aimed to investigate the epidemiology and antibiotic susceptibility of blood stream infections in order to gain a better understanding of their role and burden in our Burn Wound Center. Methods: This retrospective epidemiological investigation analyzed data derived from medical files of patients admitted to our Burn Wound Center having had at least one positive blood culture between 1 January and 31 December 2018. We focused on the prevalence of causative agents in blood stream infections in function of the time after injury and on their drug sensitivity. Results: Among the 363 patients admitted to our Burn Wound Center during the study period, 29 had at least one episode of blood stream infection. Gram-negative organisms accounted for 56,36% of the pathogens in blood stream infections, Gram-positives for 38,17%, and yeasts for 5,45%. Pseudomonas aeruginosa was the most common bacterium (20%), followed by Staphylococcus epidermidis (16.36%), Escherichia coli and Klebsiella pneumoniae (9,09% each). A third of the Gram-negative isolates were multidrug resistant. Gram-positive cocci were isolated from blood cultures at a median of 9 days after the injury, earlier than Gram-negative rods (median 15 days). The main sources of blood stream infections were the burn wounds, followed by infected catheters. Conclusions: Multidrug resistant bacteria must be considered when selecting empirical antibiotic therapy in septic burn patients. In our center, we need to update our antibiotic guidelines, to review the hospital infection control measures and to introduce routine typing technology.

With rising antibiotic resistance, modern medicine needs new approaches for tackling bacterial infections. Phage therapy uses the viruses of pathogenic bacteria to clear the infection. Unlike antibiotics, phage can evolve if bacteria become resistant to maintain or even increase their infectivity (coevolution). While laboratory studies can give insight into complex bacteria-phage interactions, whether they act as a true representation of phage therapy in patients is unknown. Here, we compared phage therapy in a patient to that of in vitro experiments. The patient had been admitted with aPseudomonas aeruginosainfection and was successfully treated with a phage cocktail. Bacteria were isolated before and during phage therapy, allowing us to follow bacteria-phage coevolution in the patient while doing experiments on the same clones in vitro. In vivo and in vitro, bacteria rapidly evolved resistance with little or no evidence of bacteria - phage coevolution. Although resistance mechanisms differed, parallel resistance - virulence trade-offs were found in vivo and in vitro. Therefore, phage resistance could increase treatment success and our results indicate to what extent bacteria - phage evolutionary dynamics can be predicted from in vitro experiments.

With rising antibiotic resistance, there has been increasing interest in treating pathogenic bacteria with bacteriophages (phage therapy). One limitation of phage therapy is the ease at which bacteria can evolve resistance. Negative effects of resistance may be mitigated when resistance results in reduced bacterial growth and virulence, or when phage coevolves to overcome resistance. Resistance evolution and its consequences are contingent on the bacteria-phage combination and their environmental context, making therapeutic outcomes hard to predict. One solution might be to conduct 'in vitro evolutionary simulations' using bacteria-phage combinations from the therapeutic context. Overall, our aim was to investigate parallels between in vitro experiments and in vivo dynamics in a human participant. Evolutionary dynamics were similar, with high levels of resistance evolving quickly with limited evidence of phage evolution. Resistant bacteria-evolved in vitro and in vivo-had lower virulence. In vivo, this was linked to lower growth rates of resistant isolates, whereas in vitro phage resistant isolates evolved greater biofilm production. Population sequencing suggests resistance resulted from selection on de novo mutations rather than sorting of existing variants. These results highlight the speed at which phage resistance can evolve in vivo, and how in vitro experiments may give useful insights for clinical evolutionary outcomes.

With rising antibiotic resistance, there has been increasing interest in treating pathogenic bacteria with bacteriophages (phage therapy). One limitation of phage therapy is the ease at which bacteria can evolve resistance. Negative effects of resistance may be mitigated when resistance results in reduced bacterial growth and virulence, or when phage coevolve to overcome resistance. Resistance evolution and its consequences are contingent on the bacteria-phage combination and their environmental context, making therapeutic outcomes hard to predict. One solution might be to conduct “in vitro evolutionary simulations” using bacteria-phage combinations from the therapeutic context. Overall, our aim was to investigate parallels between in vitro experiments and in vivo dynamics in a human participant. Evolutionary dynamics were similar, with high levels of resistance evolving quickly with limited evidence of phage evolution. Resistant bacteria – evolved in vitro and in vivo - had lower virulence. In vivo, this was linked to lower growth rates of resistant isolates, whereas in vitro phage resistant isolates evolved greater biofilm production. Population sequencing suggests resistance resulted from selection on de novo mutations rather than sorting of existing variants. These results highlight the speed at which phage resistance can evolve in vivo, and in vitro experiments may give useful insights for clinical evolutionary outcomes.

In Belgium, the incorporation of phages into magistral preparations for human application has been permitted since 2018. The stability of such preparations is of high importance to guarantee quality and efficacy throughout treatments. We evaluated the ability to preserve infectivity of four different phages active against three different bacterial species in five different buffer and infusion solutions commonly used in medicine and biotechnological manufacturing processes, at two different concentrations (9 and 7 log pfu/mL), stored at 4 °C. DPBS without Ca2+ and Mg2+ was found to be the best option, compared to the other solutions. Suspensions with phage concentrations of 7 log pfu/mL were unsuited as their activity dropped below the effective therapeutic dose (6–9 log pfu/mL), even after one week of storage at 4 °C. Strong variability between phages was observed, with Acinetobacter baumannii phage Acibel004 being stable in four out of five different solutions. We also studied the long term storage of lyophilized staphylococcal phage ISP, and found that the titer could be preserved during a period of almost 8 years when sucrose and trehalose were used as stabilizers. After rehydration of the lyophilized ISP phage in saline, the phage solutions remained stable at 4 °C during a period of 126 days.

Burkholderia multivorans is a member of the Burkholderia cepacia complex (Bcc), notorious for its pathogenicity in persons with cystic fibrosis. Epidemiological surveillance suggests that patients predominantly acquire B. multivorans from environmental sources, with rare cases of patient-to-patient transmission. Here we report on the genomic analysis of thirteen isolates from an endemic B. multivorans strain infecting four cystic fibrosis patients treated in different pediatric cystic fibrosis centers in Belgium, with no evidence of cross-infection. All isolates share an identical sequence type (ST-742) but whole genome analysis shows that they exhibit peculiar patterns of genomic diversity between patients. By combining short and long reads sequencing technologies, we highlight key differences in terms of small nucleotide polymorphisms indicative of low rates of adaptive evolution within patient, and well-defined, hundred kbps-long segments of high enrichment in mutations between patients. In addition, we observed large structural genomic variations amongst the isolates which revealed different plasmid contents, active roles for transposase IS3 and IS5 in the deactivation of genes, and mobile prophage elements. Our study shows limited within-patient B. multivorans evolution and high between-patient strain diversity, indicating that an environmental microdiverse reservoir must be present for this endemic strain, in which active diversification is taking place. Furthermore, our analysis also reveals a set of 30 parallel adaptations across multiple patients, indicating that the specific genomic background of a given strain may dictate the route of adaptation within the cystic fibrosis lung., Author summary In many countries, Burkholderia multivorans is the most prevalent species within the Burkholderia cepacia complex (Bcc) found infecting the lungs of patients with cystic fibrosis (CF). Its positive identification is of immediate concern to the health of the patient as it is notoriously hard to eradicate using antibiotics and can cause necrosis of the lung tissues (cepacia syndrome). Infection control measures reduced the prevalence of B. cenocepacia in CF wards, but patients continue to acquire infections by B. multivorans from environmental sources. In most reported cases, the infecting strains are unique except in rare cases in which cross-infection is observed between patients. We report here an endemic strain of B. multivorans with sequence type ST-742 that has been infecting multiple patients, without evidence for cross-infection. We investigated the epidemiology and genomics of this ST-742 strain and show that it is microdiverse, as isolates between-patients exhibit numerous genomic differences, at scales that have not been observed previously when looking at evolutionary trajectories within-patients. Additionally, we found that the specific genomic background of a given strain may dictate the strategy of adaptation within the CF lung.

Background The Democratic Republic of the Congo (DRC) has one of the highest neonatal death rates (between 14% and 28%) in the world. In the DRC, neonatal sepsis causes 15.6% of this mortality, but data on the bacterial etiology and associated drug susceptibility are lacking. Methods Hemocultures of 150 neonates with possible early-onset neonatal sepsis (pEOS) were obtained at the Hôpital Provincial Général de Référence de Bukavu (Bukavu, DRC). The newborns with pEOS received an empirical first-line antimicrobial treatment (ampicillin, cefotaxime, and gentamicin) based on the synopsis of international guidelines for the management of EOS that are in line with World Health Organization (WHO) recommendations. Isolates were identified using matrix-assisted laser desorption/ ionization time-of-flight mass spectrophotometry. Antibiotic resistance was assessed using the disk diffusion method. Results Fifty strains were obtained from 48 patients and identified. The 3 most prevalent species were Enterobacter cloacae complex (42%), Klebsiella pneumoniae (18%), and Serratia marcescens (12%). Enterobacter cloacae isolates were resistant to all first-line antibiotics. All K. pneumoniae and S. marcescens isolates were resistant to ampicillin, and the majority of the K. pneumoniae and half of the S. marcescens isolates were resistant to both cefotaxime and gentamicin. All E. cloacae complex strains, 89% of K. pneumoniae, and half of S. marcescens had an extended-spectrum ß-lactamase phenotype. Conclusions The most prevalent pathogens causing EOS in Bukavu were E. cloacae complex, K. pneumoniae, and S. marcescens. Most of these isolates were resistant to the WHO-recommended antibiotics.

Non-typhoidal Salmonella present a major threat to animal and human health as food-borne infectious agents. We characterized 91 bacterial isolates from Armenia and Georgia in detail, using a suite of assays including conventional microbiological methods, determining antimicrobial susceptibility profiles, matrix assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry, serotyping (using the White-Kauffmann-Le Minor scheme) and genotyping (repetitive element sequence-based PCR (rep-PCR)). No less than 61.5% of the isolates were shown to be multidrug-resistant. A new antimicrobial treatment strategy is urgently needed. Phage therapy, the therapeutic use of (bacterio-) phages, the bacterial viruses, to treat bacterial infections, is increasingly put forward as an additional tool for combatting antibiotic resistant infections. Therefore, we used this representative set of well-characterized Salmonella isolates to analyze the therapeutic potential of eleven single phages and selected phage cocktails from the bacteriophage collection of the Eliava Institute (Georgia). All isolates were shown to be susceptible to at least one of the tested phage clones or their combinations. In addition, genome sequencing of these phages revealed them as members of existing phage genera (Felixounavirus, Seunavirus, Viunavirus and Tequintavirus) and did not show genome-based counter indications towards their applicability against non-typhoidal Salmonella in a phage therapy or in an agro-food setting. ispartof: VIRUSES-BASEL vol:12 issue:12 ispartof: location:Switzerland status: published

Non-typhoidal Salmonella present a major threat to animal and human health as food-borne infectious agents. We characterized 91 bacterial isolates from Armenia and Georgia in detail, using a suite of assays including conventional microbiological methods, determining antimicrobial susceptibility profiles, matrix assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry, serotyping (using the White-Kauffmann-Le Minor scheme) and genotyping (repetitive element sequence-based PCR (rep-PCR)). No less than 61.5% of the isolates were shown to be multidrug-resistant. A new antimicrobial treatment strategy is urgently needed. Phage therapy, the therapeutic use of (bacterio-) phages, the bacterial viruses, to treat bacterial infections, is increasingly put forward as an additional tool for combatting antibiotic resistant infections. Therefore, we used this representative set of well-characterized Salmonella isolates to analyze the therapeutic potential of eleven single phages and selected phage cocktails from the bacteriophage collection of the Eliava Institute (Georgia). All isolates were shown to be susceptible to at least one of the tested phage clones or their combinations. In addition, genome sequencing of these phages revealed them as members of existing phage genera (Felixounavirus, Seunavirus, Viunavirus and Tequintavirus) and did not show genome-based counter indications towards their applicability against non-typhoidal Salmonella in a phage therapy or in an agro-food setting.

BackgroundBacterial vaginosis (BV) is the most common gynecological condition in women of reproductive age and associated with adverse pregnancy outcomes. In the Democratic Republic of the Congo (DRC), neonatal mortality rate is as high as 2.8 percent with preterm birth (PTB) and low birth weight (LBW) as leading causes. Because no studies have addressed BV in DRC, we aimed to investigate the prevalence of BV, the risk factors and the association between BV and adverse pregnancy outcomes in a population of pregnant women from Bukavu, DRC.MethodsA total of 533 pregnant women in the second trimester of pregnancy were recruited in the Provincial Reference Hospital of Bukavu, DRC, between January and October 2017, and followed until delivery. Clinical and sociodemographic data of mother and newborn, and data on (vaginal) hygiene practices, sexual behavior and reproductive history were collected. BV was diagnosed by Nugent scoring of Gram-stained vaginal smears. Two multivariate regression models were built to identify risk factors for BV and to investigate BV as a risk factor for adverse pregnancy outcomes.ResultsThe prevalence of BV was 26.3% and approximately half of the women with BV were asymptomatic. Independent risk factors for BV were the use of alternatives to water for intravaginal washing, concurrent partners, unemployed status, the presence of vaginalCandidaand clay consumption. BV was independently associated with both LBW and PTB of an infant with LBW.ConclusionThe prevalence of BV in Bukavu is high but in line with the global average. BV was associated with adverse pregnancy outcomes in our study population. Hence, research on modifiable risk factor-based interventions to reduce the prevalence of BV, and on screening/treatment of BV during antenatal care should be explored to reduce neonatal mortality and morbidity.

Dissemination of antibiotic resistance is a major concern, especially in aquatic environments, where pollution contributes for resistant bacteria selection. These strains may have serious health implications, especially for endangered species, including the sea turtles' hawksbill Eretmochelys imbricata and green turtles Chelonia mydas. We aimed to evaluate the presence of antibiotic resistant pseudomonads in wild sea turtles from Principe Island, Sao Tome and Principe, Guinea Gulf. Isolates were obtained from oral and cloacal swabs of free-living turtles by conventional techniques. Pseudomonads screening was performed by multiplex-PCR (oprl/oprL) and biochemical identification and antibiotic resistance profiling were achieved using Vitek2. All pseudomonad isolates were genotyped by Rep-PCR. Thirteen isolates were oprl-positive and classified as pseudomonads, eight from the genus Pseudomonas with the species P. aeruginosa, P. stutzeri, and P. mendocina, and five co-isolated Alcaligenes faecalis. The P. aeruginosa isolate was also oprL-positive. Regarding isolates susceptibility profile, 38.5% were susceptible to all antibiotics tested, and multidrug resistant (MDR) strains were not identified. DNA fingerprinting did not show any specific clonal-cluster similarity. Data on the worldwide incidence of antibiotic resistance among wildlife is still very scarce, especially concerning remote tropical areas. Since Pseudomonas genus has emerged as a group of increasingly reported opportunistic microorganisms in human and veterinary medicine with high resistance levels, it could be used as a tool for environmental resistance surveillance, particularly considering their ubiquity. Oceandrio de Lisboa, Portugal Marine Turtle Conservation Act - U.S. Fish & Wildlife Service grant Interdisciplinary Research Centre for Animal Health, Faculty of Veterinary Medicine, University of Lisbon (FMV/UL) [UID/CVT/00276/2013] Laboratory of Molecular and Cellular Technology, Queen Astrid Military Hospital, Brussels, Belgium info:eu-repo/semantics/publishedVersion

To determine phage titers accurately, reproducibly and in a non-laborious and cost-effective manner, we describe the development of a qPCR platform for molecular quantification of five phages present in bacteriophage cocktail 2 (BFC2). We compared the performance of this molecular approach, with regard to quantification and reproducibility, with the standard culture-based double agar overlay method (DAO). We demonstrated that quantification of each of the five phages in BFC2 was possible by means of qPCR, without prior DNA extraction, but yields were significantly higher in comparison to DAO. Although DAO is assumed to provide an indication of the number of infective phage particles, whereas qPCR only provides information on the number of phage genomes, the difference in yield (qPCR/DAO ratio) was observed to be phage-dependent and appeared rather constant for all phages when analyzing different (freshly prepared) stocks of these phages. While DAO is necessary to determine sensitivity of clinical strains against phages in clinical applications, qPCR might be a valid alternative for rapid and reproducible quantification of freshly prepared stocks, after initial establishment of a correction factor towards DAO.

Bacteriophages (phages for short) are increasingly put forward as potential (additional) tools in the fight against the worldwide antibiotic crisis. However, the setup of clinical trials, which are necessary to demonstrate the efficacy of phages and to optimize their clinical application protocols, and consequently to their implementation in the clinic is still hindered by the lack of an adapted regulatory framework. Although some (local) progresses have been made in recent years, no real paradigm shift has occurred. This chapter discusses the current status in Europe with regard to the two most pertinent barriers to phage therapy: the regulatory and intellectual property protection issues.

Ten Belgian travelers returned from Mali with a Schistosoma haematobium-Schistosoma bovis hybrid infection, confirmed by DNA sequencing from eggs. Clinical symptoms and laboratory findings resembled those of classic acute schistosomiasis, but the detected eggs were morphologically unusual.

This multidisciplinary expert panel opinion on bacteriophage therapy has been written in the context of a society that is confronted with an ever increasing number of antibiotic resistant bacteria. To avoid the return to a pre-antibiotic era, alternative treatments are urgently needed. The authors aim to contribute to the opinion formation of relevant stakeholders on how to potentially develop an infrastructure and legislation that paves the way for the acceptance and re-implementation of bacteriophage therapy.;

Recently, aTyphi 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, andin general. ispartof: Viruses vol:10 issue:4 ispartof: location:Switzerland status: published

Since time immemorial, phages—the viral parasites of bacteria—have been protecting Earth’s biosphere against bacterial overgrowth. Today, phages could help address the antibiotic resistance crisis that affects all of society. The greatest hurdle to the introduction of phage therapy in Western medicine is the lack of an appropriate legal and regulatory framework. Belgium is now implementing a pragmatic phage therapy framework that centers on the magistral preparation (compounding pharmacy in the US) of tailor-made phage medicines.

Correctly designed bacteriophage therapeutics are the cornerstone for a successful outcome of bacteriophage therapy. Here we overview strategies on how to choose bacteriophages and their bacterial hosts at different steps of a bacteriophage cocktail development in order to comply with all quality and safety requirements based on the already existing essentially empirical experience in bacteriophage therapy and current accomplishments in modern biomedical sciences. A modification of the classic Appelmans' method (1922) to assess stability of bacteriophage activity in liquid media is presented in order to improve the overall performance of therapeutic bacteriophages individually and collectively in the cocktail.

In this chapter we review bacteriophage production requirements to help institutions, which wish to manufacture bacteriophage products for human use in compliance with the applicable regulatory expectancies, defining production processes and implementing relevant controls ensuring quality, safety, and efficacy of the final products. The information disclosed in this chapter can also serve as a basis for discussions with competent authorities regarding the development of expedited bacteriophage product development and licensing pathways, including relevant and pragmatic requirements, and allowing for the full exploitation of bacteriophages as natural controllers of bacterial populations.

In this chapter we review bacteriophage production requirements to help institutions, which wish to manufacture bacteriophage products for human use in compliance with the applicable regulatory expectancies, defining production processes and implementing relevant controls ensuring quality, safety, and efficacy of the final products. The information disclosed in this chapter can also serve as a basis for discussions with competent authorities regarding the development of expedited bacteriophage product development and licensing pathways, including relevant and pragmatic requirements, and allowing for the full exploitation of bacteriophages as natural controllers of bacterial populations.

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, Georgia. The first paper from the Round Table was published in the Biotechnology Journal1. This In Focus article expands from this paper and includes recent developments reported since then by the Expert Round Table participants, including the implementation of the Nagoya Protocol for the applications of bacteriophages.

Bacteriophages could be used along with burn wound care products to enhance antimicrobial pressure during treatment. However, some of the components of the topical antimicrobials that are traditionally used for the prevention and treatment of burn wound infection might affect the activity of phages. Therefore, it is imperative to determine the counteraction of therapeutic phage preparations by burn wound care products before application in patients. Five phages, representatives of two morphological families (Myoviridae and Podoviridae) and active against 3 common bacterial burn wound pathogens (Acinetobacter baumannii, Pseudomonas aeruginosa and Staphylococcus aureus) were tested against 13 different products commonly used in the treatment of burn wounds. The inactivation of the phages was quite variable for different phages and different products. Majority of the anti-infective products affected phage activity negatively either immediately or in the course of time, although impact was not always significant. Products with high acidity had the most adverse effect on phages. Our findings demonstrate that during combined treatment the choice of phages and wound care products must be carefully defined in advance.

International audience; Bacteriophages have been shown to be effective for treating acute infections of the respiratory tract caused by antibiotic-resistant bacteria in animal models, but no evidence has yet been presented of their activity against pathogens in complex biological samples from chronically infected patients. We assessed the efficacy of a cocktail of ten bacteriophages infecting Pseudomonas aeruginosa following its addition to 58 sputum samples from cystic fibrosis (CF) patients collected at three different hospitals. Ten samples that did not contain P. aeruginosa were not analysed further. In the remaining 48 samples, the addition of bacteriophages led to a significant decrease in the levels of P. aeruginosa strains, as shown by comparison with controls, taking two variables (time and bacteriophages) into account (p = 0.024). In 45.8% of these samples, this decrease was accompanied by an increase in the number of bacteriophages. We also tested each of the ten bacteriophages individually against 20 colonies from each of these 48 samples and detected bacteriophage-susceptible bacteria in 64.6% of the samples. An analysis of the clinical data revealed no correlation between patient age, sex, duration of P. aeruginosa colonization, antibiotic treatment, FEV1 (forced expiratory volume in the first second) and the efficacy of bacteriophages. The demonstration that bacteriophages infect their bacterial hosts in the sputum environment, regardless of the clinical characteristics of the patients, represents a major step towards the development of bacteriophage therapy to treat chronic lung infections.

Lectin-like bacteriocins of the LlpA family, originally identified in plant-associated bacteria, are narrow-spectrum antibacterial proteins composed of two tandemly organized monocot mannose-binding lectin (MMBL) domains. The LlpA-like bacteriocin of Pseudomonas aeruginosa C1433, pyocin L1, lacks any similarity to known P. aeruginosa bacteriocins. The initial interaction of pyocin L1 with target cells is mediated by binding to D-rhamnose, present in the common polysaccharide antigen of lipopolysaccharides but the actual cytotoxic mechanism is unknown. In this study, we characterized the activity range of pyocin L1 and two additional L pyocins revealed by genome mining, representing two highly diverged LlpA groups in P. aeruginosa. The recombinant proteins exhibit species-specific antagonistic activities down to nanomolar concentrations against clinical and environmental P. aeruginosa strains, including several multidrug-resistant isolates. The overlap in target strain spectrum between two close homologues of the pyocin L1 group is only minimal, contrasting with the considerable spectral redundancy of LlpA proteins reported for other Pseudomonas species. No correlation was found between L pyocin susceptibility and phylogenetic relatedness of P. aeruginosa isolates. Sensitive strains were retrieved in 13 out of 15 O serotypes tested, excluding the possibility that the highly variable and immunogenic O serotype antigen of the lipopolysaccharide coating would represent a dominant susceptibility-discriminating factor. ispartof: MicrobiologyOpen vol:3 issue:6 pages:875-884 ispartof: location:England status: published

Bacteriophages could help address the antibiotic resistance crisis that impacts health systems all over the world. In 2011, the European Commission formally confirmed that phage products used as therapeutics are medicinal products and thus manufacturers need to navigate the extremely arduous and enormously expensive medicine development and marketing pathway. However, up until now, not one therapeutic phage product has made it to the European market, and yet clinicians are under increasing pressure to use phages in the treatment of multidrug-resistant bacterial infections. While a handful of small European enterprises are struggling to squeeze therapeutic phage products through the conventional and centralised European medicinal products funnel, some clinicians and academics are exploring (European) national solutions to accelerate the availability of phages for the treatment of an increasing number of desperate patients. This mini-review summarises the actual status and perspectives of clinical phage application in Europe.

Pseudomonas aeruginosa is a major opportunistic pathogen in cystic fibrosis (CF) patients and causes a wide range of infections among other susceptible populations. Its inherent resistance to many antimicrobials also makes it difficult to treat infections with this pathogen. Recent evidence has highlighted the diversity of this species, yet despite this, the majority of studies on virulence and pathogenesis focus on a small number of strains. There is a pressing need for a P. aeruginosa reference panel to harmonize and coordinate the collective efforts of the P. aeruginosa research community. We have collated a panel of 43 P. aeruginosa strains that reflects the organism's diversity. In addition to the commonly studied clones, this panel includes transmissible strains, sequential CF isolates, strains with specific virulence characteristics, and strains that represent serotype, genotype or geographic diversity. This focussed panel of P. aeruginosa isolates will help accelerate and consolidate the discovery of virulence determinants, improve our understanding of the pathogenesis of infections caused by this pathogen, and provide the community with a valuable resource for the testing of novel therapeutic agents.