Amit Rimon

Background: Cutibacterium avidum is an emerging opportunistic pathogen responsible for device-associated infections, including prosthetic joint and breast implant infections. Unlike its relative C. acnes, for which phage therapy has been explored, C. avidum infections are recalcitrant to antibiotics, and no infecting bacteriophages have been described to date. Here, we report the isolation and characterization of ΦCA1NRNZ, to the best of our knowledge, the first lytic phage described against C. avidum. Methods: ΦCA1NRNZ was obtained from wastewater sampling at the Sorek Treatment Facility in Jerusalem. Wastewater metagenomics, transmission electron microscopy, genome sequencing, host-range testing, efficiency of plating (EOP), aerobic and anaerobic lysis assays, and antibiofilm assays against mature C. avidum biofilms were performed. Results: Metagenomic analysis indicated low and transient detection of C. avidum-classified reads in wastewater. ΦCA1NRNZ was identified as a long-tailed Caudoviricetes with a ~320 nm virion. Its 33,712 bp dsDNA genome (GenBank PV441878.1) encodes 46 predicted proteins, shares 76.5% nucleotide identity with C. acnes phage ΦFD1, and contains divergent tail-fiber and host-recognition genes. No known bacterial virulence, toxin, human pathogenicity-associated, or antibiotic-resistance genes were identified. ΦCA1NRNZ lysed all 11 clinical C. avidum isolates tested under aerobic and anaerobic conditions, with EOP values of 0.11–5.55, mean 1.87, and showed no lytic activity against 25 C. acnes isolates. Against mature biofilms, ΦCA1NRNZ reduced total biomass by 28.4% (p = 0.014), reduced viable cell counts by approximately two logs, and increased extracellular ATP release (p < 0.001). Conclusions: The strict species specificity and significant in vitro antibiofilm activity of ΦCA1NRNZ support its potential for phage therapy of device-associated C. avidum infections.

Moral injury is increasingly recognized as a significant concern among medical personnel and first responders, particularly in high-stress healthcare and emergency settings. This review aims to synthesize current evidence on the prevalence, risk factors, and outcomes of moral injury among medical personnel and first responders across diverse healthcare and emergency response environments. We included peer-reviewed studies reporting on moral injury among medical personnel or first responders in any healthcare or emergency response setting, excluding studies that did not report original data or focused solely on military populations. We systematically searched PubMed, Google Scholar, and Central, up to April 2025. Risk of bias was assessed directly from the manuscripts. Data were synthesized narratively and, where possible, pooled using random-effects meta-analysis. A total of 41 studies involving 14,500 participants were included. The prevalence of moral injury ranged from 4.1% to 69.44% across settings. Key risk factors identified included exposure to traumatic events, organizational constraints, and lack of support. Meta-analysis indicated a significant association between moral injury and symptoms of PTSD. The evidence is limited by heterogeneity in measurement tools and study designs, as well as a moderate risk of bias in several included studies. In conclusion, moral injury is prevalent among medical personnel and first responders, with important implications for mental health interventions and organizational policy. This review was not funded externally, and is registered in PROSPERO (CRD420251019492).

Background: Antibiotic-resistant Pseudomonas aeruginosa (P. aeruginosa) strains are an increasing cause of morbidity and mortality. Pulsed blue light (PBL) enhances porphyrin-induced reactive oxygen species and has been clinically shown to be harmless to the skin at low doses. Bacteriophages, viruses that infect bacteria, offer a promising non-antibiotic bactericidal approach. This study investigates the potential synergism between low-dose PBL and phage therapy against P. aeruginosa in planktonic cultures and preformed biofilms. Methods: We conducted a factorial dose–response in vitro study combining P. aeruginosa-specific phages with PBL (457 nm, 33 kHz) on both PA14 and multidrug-resistant PATZ2 strains. After excluding direct PBL effects on phage titer or activity, we assessed effectiveness on planktonic cultures using growth curve analysis (via growth_curve_outcomes, a newly developed, Python-based tool available on GitHub) , CFU, and PFU. Biofilm efficacy was evaluated using CFU post-sonication, crystal violet staining, and live/dead staining with confocal microscopy. Finally, we assessed reactive oxygen species (ROS) as a potential mechanism using the nitro blue tetrazolium reduction assay. ANOVA or Kruskal–Wallis tests with post hoc Tukey or Conover–Iman tests were used for comparisons (n = 5 biological replicates and technical triplicates). Results: The bacterial growth lag phase was significantly extended for phage alone or PBL alone, with a synergistic effect of up to 144% (p < 0.001 for all), achieving a 9 log CFU/mL reduction at 24 h (p < 0.001). In preformed biofilms, synergistic combinations significantly reduced biofilm biomass and bacterial viability (% Live, median (IQR): Control 80%; Phage 40%; PBL 25%; PBL&Phage 15%, p < 0.001). Mechanistically, PBL triggered transient ROS in planktonic cultures, amplified by phage co-treatment, while a biphasic ROS pattern in biofilms reflected time-dependent synergy. Conclusions: Phage therapy combined with PBL demonstrates a synergistic bactericidal effect against P. aeruginosa in both planktonic cultures and biofilms. Given the strong safety profile of PBL and phages, this approach may lead to a novel, antibiotic-complementary, safe treatment modality for patients suffering from difficult-to-treat antibiotic-resistant infections and biofilm-associated infections.

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.

Introduction: Pseudomonas aeruginosa is a major opportunistic pathogen associated with healthcare-associated infections. The rise of antibiotic-resistant strains necessitates alternative treatment strategies, with bacteriophage therapy being a promising approach. Methods: Six bacteriophages were isolated from sewage samples. Phage isolation involved centrifugation, filtration, and plaque assays. The morphology of each was examined using Transmission Electron Microscopy (TEM). Genomic DNA was sequenced analyzed and compared. Phages lytic activity was assessed using growth curve analysis. Results: The six phages displayed distinct genomic and morphological characteristics, in three genomic clusters. No known virulence or antibiotic resistance genes were detected, indicating their safety for therapeutic use. TEM analysis revealed diverse morphologies, with some phages belonging to the Siphoviridae family and others to the Myoviridae family. Lysogenic phages demonstrated less effective lytic activity. Conclusion: Some of these phages are promising candidates for the research of phage therapy efficacy, and the lytic phages can be used against P. aeruginosa infections.

Antibiotic-resistant Pseudomonas aeruginosa (PA) is a critical health threat. Novel treatment approaches are urgently required in this post-antibiotic era. In the current study, we investigated the bactericidal combinatorial potential of two non-antibiotic alternative approaches: phage therapy and pulsed blue light (PBL). Bacteriophages (phages), are viruses that specifically infect and lyse bacteria without harming eukaryotic cells. Pulsed blue light (PBL) alters bacterial membranes and was clinically shown to be innocuous to the skin in low doses. Here, using a low dose 457nm, 33KHz PBL combined with specific PA targeting phages, we demonstrated a synergistic effect that achieved complete inhibition of planktonic bacteria and a 40% reduction in formed biofilms. As part of this study, we also developed a user-friendly python-based tool for extraction of growth curve outcomes. In vivo studies are warranted for further validation of this combinatorial treatment. This approach may lead to a novel, antibiotic complementary modality to help patients suffering from difficult-to-treat antibiotic-resistant infections. One Sentence Summary: Low-dose pulsed blue light and phage therapy have a synergistic bactericidal effect on Pseudomonas aeruginosa planktonic cultures and formed biofilm

Acne vulgaris is a common neutrophil-driven inflammatory skin disorder in which Cutibacterium acnes (C. acnes) is known to play a key role. For decades, antibiotics have been widely employed to treat acne vulgaris, inevitably resulting in increased bacterial antibiotic resistance. Phage therapy is a promising strategy to combat the growing challenge of antibiotic-resistant bacteria, utilizing viruses that specifically lyse bacteria. Herein, we explore the feasibility of phage therapy against C. acnes. Eight novel phages, isolated in our laboratory, and commonly used antibiotics eradicate 100% of clinically isolated C. acnes strains. Topical phage therapy in a C. acnes-induced acne-like lesions mouse model affords significantly superior clinical and histological scores. Moreover, the decrease in inflammatory response was reflected by the reduced expression of chemokine CXCL2, neutrophil infiltration, and other inflammatory cytokines when compared with the infected-untreated group. Overall, these findings indicate the potential of phage therapy for acne vulgaris as an additional tool to conventional antibiotics.

Exploring the intricacies of host-pathogen communication is vital in order to understand why some microbes persist within a host, while others are effectively cleared. As such, host-pathogen communication is an urgent area of research underpinning human health and disease, especially given the emerging concerns of antibiotic resistance. Understanding host-pathogen pathways requires intricate knowledge in the fields of both microbiology and immunology. Living in a world of specialists, where scientists sometimes invest their whole career studying one organism, a specific pathway or a protein, multidisciplinary discussions of host-pathogen interactions are highly needed. This international conference will provide such a forum for scientific exchange at the highest level, between scientists from different research areas related to host-pathogen interactions, with the aim to trigger fruitful collaborations addressing the urgent questions in the field. This meeting has an additional special focus of bringing researchers from Ireland, Denmark and Israel together to learn about cutting edge biology and form new collaborations. Thus, the conference will be a showcase for the exciting and original research emanating from these three small but innovative countries.

Antibiotic-resistant Cutibacterium acnes has been reported worldwide, but data from Israeli patients...