Bacteriophage (phages) are viruses that exclusively use bacterial cells for propagation, killing the bacterial host in the process. In phage therapy, phages are used to reduce bacterial numbers, thereby curing bacterial infections. Although this principle is conceptually straightforward, its practical application faces several hurdles. In this Primer, the practical aspects of phage therapy are outlined. We introduce the microbiological methods used to prepare and characterize phages and elucidate their interactions with bacteria. The discussion covers how the information in complete phage genome sequences is used, along with how RNA sequencing can enhance our understanding of phage biology. Selection parameters for therapeutic phages for clinical applications and key elements in industrial-scale phage production are provided. A summary of clinical trials both past and present, phage administration and dosing issues is analysed, as well as limitations associated with phage therapy and mitigation strategies. Finally, we speculate on the future of phage therapy. Phage therapy uses bacteriophages to target bacteria and treat infections. In this Primer, Skurnik et al. discuss the practical aspects of phage therapy, from the microbiological methods used to prepare and characterize phages to the selection of therapeutic phages for clinical applications.

The use of bacteriophage (phage) to treat bacterial infection of airways in persons with cystic fibrosis (CF) is gaining interest. However, phenotypic diversification of bacteria during chronic airway infection presents a potential challenge to this therapy. We recovered and subcultured two or three Burkholderia colonies from each of 12 CF sputum samples. All isolates were tested for their susceptibility to a panel of 65 Burkholderia-targeting phages. We observed that 9 (75%) of the 12 colony sets comprised mixtures of isolates that were sensitive or resistant to one or more of the phages tested. The occurrence of mixed populations of phage-sensitive and phageresistant Burkholderia in individuals with CF needs to be considered in the development of phage therapy for this patient population.

OBJECTIVES:Mycoplasma pneumoniae (MP) is a prevalent bacterial respiratory pathogen known for cyclic epidemics every 3-5 years, potentially linked to waning immunity. Following the global decline post-coronavirus disease 2019, MP has re-emerged since late 2023. Given the extended interval since the last epidemic, we compared pediatric MP's clinical presentation and outcomes during the recent and previous outbreaks spanning 17 years at a tertiary center in Jerusalem, Israel. METHODS:We conducted a retrospective cohort study at Hadassah Medical Center, analyzing demographic, clinical and treatment data from pediatric patients (0-17 years) with PCR-confirmed MP. In 2024, daily reports updated physicians on positive cases. We compared 2024 data (221 patients) with cohorts from 2007 to 2017 (352 patients) and initial epidemic years (2012, 2015; 139 patients). RESULTS:The 2024 epidemic showed an increased median age (8.0 vs. 5.8 years; P = 0.0002), higher female prevalence (56% vs. 44%; P = 0.007), and altered clinical manifestations: increased cough (78% vs. 63%; P = 0.0002), fever (79% vs. 64%; P = 0.0004), consolidation on radiograph (48% vs. 39%; P = 0.0244) and pleural effusions (5% vs. 0%; P < 0.0001). Rash incidence decreased (8% vs. 16%; P = 0.0031). Significant differences in age, sex, pleural effusions and rash persisted when comparing initial epidemic years. Early emergency department diagnosis rose in 2024 from 43% to 80%. The hospitalization rate decreased from 70% to 30% and was overall lower than 2007-2017 (81%; P < 0.001). CONCLUSIONS:Pediatric MP presentation in 2024 differed notably from prior epidemics, marked by increased severe pneumonia in older children. Enhanced awareness facilitated rapid diagnostics, reducing hospital admissions, unnecessary tests and inappropriate antibiotic use.

Listeriosis is a serious food-borne bacterial infection caused by Listeria monocytogenes. L. monocytogenes is a facultative intracellular bacterial species that can replicate inside human cells, as well as thrive in a variety of environments, including soil, decaying vegetation, animal intestines and foods such as unpasteurized dairy products, soft cheese, raw meat, fish, seafood, vegetables and fruits. Clinically, L. monocytogenes can cause gastroenteritis in healthy individuals or serious invasive infections in at-risk populations. For example, maternal-fetal infections during pregnancy can lead to adverse pregnancy outcomes. In the elderly and immunosuppressed, listeriosis can cause septicaemia and central nervous system infections (also known as neurolisteriosis) with high mortality and risk of long-term sequelae. Genomic studies have identified four lineages of L. monocytogenes, with lineage I comprising the most virulent strains. The pathogenicity of L. monocytogenes reflects its ability to resist gastric and bile acids, colonize the intestinal lumen, cross the intestinal barrier, survive intracellularly in the bloodstream, evade immune responses, and cross the placental and blood-brain barriers. Diagnosis of listeriosis (septicaemia, neurolisteriosis, maternal-neonatal listeriosis or focal listeriosis) involves clinical observations and microbiological testing based on bacterial culture or DNA detection in individuals with prior antimicrobial therapy. Treatment typically involves aminopenicillins and aminoglycosides, with no evidence of clinically meaningful acquired antimicrobial resistance. Although listeriosis is a well-studied infection, a clearer picture of its global burden, its pathophysiology, the dynamics of the L. monocytogenes population and transmission routes is needed. On the host side, new risk factors, including genetics, and new treatment regimens to improve patient outcomes need to be identified.

OBJECTIVES:This study aimed to identify and develop a standard set of competencies needed for members of an antimicrobial stewardship (AMS) team. METHODS:A panel of experts in AMS utilized a survey based on a modified Delphi technique to establish consensus on AMS competencies. RESULTS:The authors identified 88 competencies covering 15 domains with strong agreement by 58 international experts. The identified domains were: the objectives of AMS; management of infection; microbiology diagnostics; pharmacology of antimicrobial agents; general principles of antibiotic use; the structure and the position of AMS; antimicrobial stewardship interventions; AMS in special settings; surveillance and monitoring; behaviour change and communication; infection prevention and control; quality management and patient safety; information technology (IT) support; communication with patients and general public and governance/policy framework. The consensus-based list of competencies was ratified by the European Study Group for Antimicrobial Stewardship Executive Committee. CONCLUSIONS:The identified competencies can be used as a tool in planning of AMS training and to develop and optimize AMS programmes worldwide.

Abstract Non-resolving bacterial infections involve biofilm formation and are often complicating treatments. Utilizing lytic bacteriophages with antibiotics holds promise in biofilm eradication. Accurately matching phage-antibiotic combinations against target bacteria, termed Clinical Phage Microbiology (CPM), is crucial in effective phage therapy treatments. However, compared to planktonic cultures, performing CPM on biofilm infections poses a significant challenge due to the lack of effective methods and a standard protocol. This study compared various CPM approaches in biofilms. To this end, the activity of five phages was assessed against Pseudomonas aeruginosa biofilms using nine methods and multiple approaches. Here, we discuss various aspects of each technique, including sensitivity, duration, ease of implementation in diagnostic labs, and labor. Finally, we offer a preliminary protocol for testing phage-sensitivity in biofilm, which was tested on various bacteria species, and may serve as a basis for comprehensive CPM in biofilm. ### Competing Interest Statement The authors have declared no competing interest.

Background. While Mycoplasma pneumoniae (MP) infections typically present as a respiratory disease, extrapulmonary manifestations are well-documented. Historically, cardiac involvement has been considered uncommon (1%-2%); however, recent observations suggest higher rates, especially in MP ICU patients. This study aims to characterize the prevalence, clinical spectrum, and outcomes of hospitalized patients with MP and cardiac manifestations. Methods. We conducted a cohort study at Hadassah Medical Center, Jerusalem, Israel, including all inpatients with a positive PCR for MP from 2007 to mid-2024. Cardiac involvement included congestive heart failure (CHF), arrhythmias, acute coronary syndrome (ACS), peri/myocarditis, and isolated troponin elevation. Results. Of 1305 MP-positive patients (mean age 33.4 years), 152 (11.6%) were found to have cardiac involvement-17% among adult patients and 4.9% among children (P < .001). In adults, CHF and arrhythmias were most common (each 34.7%), followed by ACS (10.5%), peri/myocarditis (15.3%), and isolated troponinemia (9.7%). ICU admission occurred in 50% of adults with cardiac involvement and was significantly higher in arrhythmias and peri/myocarditis groups. In-hospital mortality among adults was high at 22.6%. Predictors of mortality included ICU admission (aOR 7.76; CI: 2.78-21.66), older age (aOR per year increase: 1.03; CI: 1.01-1.06), and primary diagnosis other than MP (aOR 3.57; CI: 1.34-9.51). Pediatric cardiac involvement primarily presented as arrhythmia (42.9%). Conclusions. Cardiac involvement in hospitalized MP-infected adults is more common than previously recognized (17%) and carries substantial morbidity and mortality risks. Early evaluation for cardiac complications is crucial in MP-infected hospitalized patients presenting with severe illness or unexplained cardiac symptoms.

Left ventricular assist devices (LVAD) are increasingly used for management of heart failure; infection remains a frequent complication. Phage therapy has been successful in a variety of antibiotic refractory infections and is of interest in treating LVAD infections. We performed a retrospective review of four patients that underwent five separate courses of intravenous (IV) phage therapy with concomitant antibiotic for treatment of endovascular Pseudomonas aeruginosa LVAD infection. We assessed phage susceptibility, bacterial strain sequencing, serum neutralization, biofilm activity, and shelf-life of phage preparations. Five treatments of one to four wild-type virulent phage(s) were administered for 14-51 days after informed consent and regulatory approval. There was no successful outcome. Breakthrough bacteremia occurred in four of five treatments. Two patients died from the underlying infection. We noted a variable decline in phage susceptibility following three of five treatments, four of four tested developed serum neutralization, and prophage presence was confirmed in isolates of two tested patients. Two phage preparations showed an initial titer drop. Phage biofilm activity was confirmed in two. Phage susceptibility alone was not predictive of clinical efficacy in P. aeruginosa endovascular LVAD infection. IV phage was associated with serum neutralization in most cases though lack of clinical effect may be multifactorial including presence of multiple bacterial isolates with varying phage susceptibility, presence of prophages, decline in phage titers, and possible lack of biofilm activity. Breakthrough bacteremia occurred frequently (while the organism remained susceptible to administered phage) and is an important safety consideration.

BACKGROUND:Phage therapy offers a promising alternative for treating serious infections, including diabetic foot ulcers (DFUs), through the lytic action of phages. This randomized double-blind study was conducted to evaluate the safety and tolerability of the TP-102 bacteriophage cocktail in patients with DFUs non-infected and infected with Staphylococcus aureus, Pseudomonas aeruginosa, and/or Acinetobacter baumannii. METHODS:Nineteen participants with DFUs were randomized after susceptibility testing. TP-102 was applied topically at 10⁹ plaque-forming units (PFUs)/mL/cm³ to the target ulcer: 1 week for non-infected DFUs and 28 days for infected DFUs (PEDIS grade 2/3). The study was conducted in Israel. FINDINGS:Main outcomes included the incidence and severity of TP-102-related adverse events, microbiological data, and ulcer healing. Thirteen patients received TP-102. No treatment-related adverse events were reported. Although the study was underpowered to determine the superiority of TP-102 over placebo, a greater proportion of patients in the TP-102 + standard of care (SOC) group showed microbiological reduction of target bacteria (t = 26) compared to the placebo + SOC group (80% versus 50%, p = 1.000). Additionally, a higher proportion of TP-102 patients reached 50% and 75% wound closure compared to placebo (5/7 [71.4%] versus 1/3 [33.3%], p = 0.500 and 2/7 [28.6%] versus none, p = 1.000, respectively). One patient in the TP-102 group achieved wound closure. CONCLUSIONS:TP-102 was well tolerated and safe, showing potential as a groundbreaking treatment in this field. Further studies are needed to confirm its safety and efficacy in larger populations with diabetic foot infections (ClinicalTrials.gov: NCT04803708). FUNDING:None to declare.

ObjectiveMembrane stripping in group B streptococcus (GBS) carriers poses an increased risk of inadequate antibiotic prophylaxis, potentially due to accelerated labor, thereby potentially impacting the management of GBS colonization during delivery. We compared the adequacy of intrapartum antibiotic prophylaxis between pregnant women colonized with GBS, who underwent membrane stripping and those who did not. The study aimed to determine whether the performance of membrane stripping, by potentially shortening labor duration, increases the risk of inadequate antibiotic prophylaxis dispensation.Study designA retrospective cohort study was conducted on GBS screen-positive women with a full-term singleton pregnancy in cephalic presentation, who were eligible for vaginal delivery. The exposed group consisted of women who underwent membrane stripping, while the unexposed group consisted of women who did not undergo membrane stripping. The primary outcome was defined as inadequate duration of antibiotic prophylaxis during labor, wherein less than 4 h of beta-lactam antibiotics were administered prior to delivery. Neonatal outcome was compared between the groups.ResultsThis retrospective cohort study comprised 1,609 women, with 129 in the exposed group (stripping group) and 1,480 in the unexposed group (no stripping group). Adequate intrapartum antibiotic prophylaxis was received by 64.3% (83/129) of the exposed group, compared to 46.9% (694/1,480) of the unexposed group (p = 0.003). Membrane stripping was associated with increased odds of receiving adequate prophylaxis (OR 1.897, 95% CI 1.185–3.037, p = 0.008). After excluding women who presented to the labor ward in active labor and delivered in less than 4 h, both the exposed and unexposed groups had similarly high rates of adequate intrapartum antibiotic prophylaxis (87.5% vs. 85.8%, respectively). No significant difference was observed in adverse neonatal outcomes between the groups.ConclusionThe provision of membrane stripping did not impede adequate intrapartum antibiotic prophylaxis and was correlated with a higher rate of sufficient prophylaxis in comparison to non-swept patients. These observations suggest that membrane stripping can be considered a safe option for ensuring adequate antibiotic prophylaxis in women colonized with GBS.

Phage therapy has re-emerged as a promising treatment for non -resolving infections. Given the lack of approved phage treatments, there is a need to establish a compassionate use pipeline. Here, we present a protocol for phage matching, treatment, and monitoring for compassionate bacteriophage use in nonresolving infections. We describe steps for consultation and request implementation, evaluating and comparing different aspects of phage activity, and phage production. We then detail procedures for multidisciplinary meetings, ethics approvals, phage therapy, and follow-up. For complete details on the use and execution of this protocol, please refer to Onallah et al. 1,2

We examined differences between social workers in hospitals versus social workers in community health services regarding levels of professional quality of life (ProQoL), proximity to COVID-19, resilience, perceived social support, and preparedness for the next pandemic during waves 3-5 of the COVID-19 pandemic in Israel (December 2020-December 2021, the main COVID-19 variants were Alpha and Delta). We also examined the moderating role of resilience, social support, preparedness for the next pandemic, and health care service type in the association between proximity to COVID-19 and ProQoL. Participants were 163 social workers from four hospitals and 98 social workers from a major health maintenance organization in the community. Social workers in both settings revealed moderate-high levels of compassion satisfaction and moderate levels of burnout and secondary traumatic stress. The study's model indicated that after controlling for the effects of the covariates, higher levels of self-reported-resilience and greater perceived organizational support were associated with higher compassion satisfaction and lower burnout and secondary traumatic stress. Furthermore, a stronger sense of preparedness for the next pandemic was related to lower levels of burnout. The model indicated that the effects of organizational support, informal social support, and preparedness on compassion satisfaction were dependent on the study group (i.e., working in hospital or community settings). Findings indicate that intervention programs should be implemented to help increase compassion satisfaction and prevent/reduce burnout and secondary traumatic stress among social workers in health care settings during health care crises. Enhancing resilience and preparedness should focus not only on the social workers as individuals but also on the institutions for which they work.

Abstract Background A growing number of compassionate phage therapy use cases reported in the last decade, with only a limited number of clinical trials conducted and very few unsuccessful clinical trials reported. However, the limited understanding of individual clinical cases and lack of successful published clinical trials provides little evidence on the role of phages in refractory infections. Our objective was to bridge between single cases to early clinical trials and to describe the compassionate use of a single same phage - PASA16 - in sixteen patients with non-resolving Pseudomonas aeruginosa infections. Methods We have collected all cases in which PASA16 was used and summarized clinical microbiology data, administration protocol, clinical data and outcome. In all instances involving intravenous phage administration (14 out of 16 cases), PASA16 phage was manufactured and provided pro-bono by Adaptive Phage Therapeutics. Results PASA16 was administered either IV, locally to infection site or by topical use to 16 patients, with data available for 15 patients, mainly for osteoarticular and foreign device associated infections. Few minor side effects were noted including elevated liver function enzymes and a transient reduction in white blood cell count. Good clinical outcome was documented in 13 out of 15 (86%). Two clinical failures were reported. Conclusion PASA16 with antibiotics was found to be relatively successful in patients who have failed previously in traditional approaches. Minimal successful duration of phage therapy was 8 days with once to twice a day administration. Such pre-phase 1 cohorts can outline the potential clinical protocols to be used and facilitate the design of future clinical trials. Disclosures Ran Nir-Paz, MD, Adaptive phage theraputics: Supplied the phage product for this study|BiomX: Advisor/Consultant|Technophage: Grant/Research Support

BACKGROUND:Persistent and resistant infections caused by bacteria are increasing in numbers and pose a treatment challenge to the medical community and public health. However, solutions with new agents that will enable effective treatment are lacking or delayed by complex development and authorizations. Bacteriophages are known as a possible solution for invasive infections for decades but were seldom used in the Western world. OBJECTIVES:To provide an overview of the current status and emerging use of bacteriophage therapy and phage-based products, as well as touch on the socioeconomic and regulatory issues surrounding their development. SOURCES:Peer-reviewed articles and authors' first-hand experience. CONTENT:Although phage therapy is making a comeback since its early discovery, there are many hurdles to its current use. The lack of appropriate standardized bacterial susceptibility testing; lack of a simple business model and authorization for the need of many phages to treat a single species infection; and the lack of knowledge on predictable outcome measures are just a few examples. In this review, we explore the possible routes for phage use, either based on local specialty centres or by industry; the current status of phage therapy, which is mainly based on single-centre or single-bacterial cohorts, and emerging clinical trials; local country-level frameworks for phage utilization even without full authorization; and the use of phage-derived products as alternatives to antibiotics. We also explore what may be the current indications based on the possible availability of phages. IMPLICATIONS:Although phages are emerging as a potential treatment for non-resolving and life-threatening infections, the models for their use and production still need to be defined by the medical community, regulatory bodies, and industry. Bacteriophages may have a great potential for infection treatment but many aspects still need to be defined before their routine use in the clinic.