Antibiotics-Basel最新文献

{"title":"Virological and Pharmaceutical Properties of Clinically Relevant Phages.","authors":"Antonios-Periklis Panagiotopoulos, Antonia P Sagona, Deny Tsakri, Stefanos Ferous, Cleo Anastassopoulou, Athanasios Tsakris","doi":"10.3390/antibiotics14050487","DOIUrl":"10.3390/antibiotics14050487","url":null,"abstract":"<p><p>As antimicrobial resistance continues to undermine the efficacy of antibiotics, the global medical community is increasingly turning to alternative treatment modalities. Among these, phage therapy has re-emerged as a promising strategy for managing multidrug-resistant bacterial infections. Herein, we present and briefly discuss eight essential attributes of clinically relevant phages for therapy, which may be categorized broadly into virological and pharmacological characteristics. Virological attributes include a broad host range, a strictly lytic life cycle and the ability to manage the emergence of bacterial resistance to phages. Comprehensive genomic and proteomic characterization forms the foundation for selecting and engineering such candidates, ensuring both safety and predictability. From a pharmacological standpoint, phages should ideally show safety across relevant formulations and routes of administration, favorable pharmacokinetics, stability during storage and scalability in manufacturing. Advances in genomic analysis, artificial intelligence-driven phage selection and formulation technologies have further accelerated the translational potential of phage therapy. By systematically addressing each of these critical attributes, this work aims to inform the rational selection and development of therapeutic phages suitable for integration into the clinical practice.</p>","PeriodicalId":54246,"journal":{"name":"Antibiotics-Basel","volume":"14 5","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12108485/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144163765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Antimicrobial Susceptibility Profiles of <i>Escherichia coli</i> Isolates from Clinical Cases of Ducks in Hungary Between 2022 and 2023.","authors":"Ádám Kerek, Ábel Szabó, Ákos Jerzsele","doi":"10.3390/antibiotics14050491","DOIUrl":"10.3390/antibiotics14050491","url":null,"abstract":"<p><p><b>Background</b>: Antimicrobial resistance (AMR) poses a growing threat to veterinary medicine and food safety. This study examines <i>Escherichia coli</i> antibiotic resistance patterns in ducks, focusing on multidrug-resistant (MDR) strains. Understanding resistance patterns and predicting MDR occurrence are critical for effective intervention strategies. <b>Methods</b>: <i>E. coli</i> isolates were collected from duck samples across multiple regions. Descriptive statistics and resistance frequency analyses were conducted. A decision tree classifier and a neural network were trained to predict MDR status. Cross-resistance relationships were visualized using graph-based models, and Monte Carlo simulations estimated MDR prevalence variations. <b>Results</b>: Monte Carlo simulations estimated an average MDR prevalence of 79.6% (95% CI: 73.1-86.1%). Key predictors in MDR classification models were enrofloxacin, neomycin, amoxicillin, and florfenicol. Strong cross-resistance associations were detected between neomycin and spectinomycin, as well as amoxicillin and doxycycline. <b>Conclusions</b>: The high prevalence of MDR strains underscores the urgent need to revise antibiotic usage guidelines in veterinary settings. The effectiveness of predictive models suggests that machine learning tools can aid in the early detection of MDR, contributing to the optimization of treatment strategies and the mitigation of resistance spread. The alarming MDR prevalence in <i>E. coli</i> isolates from ducks reinforces the importance of targeted surveillance and antimicrobial stewardship. Predictive models, including decision trees and neural networks, provide valuable insights into resistance trends, while Monte Carlo simulations further validate these findings, emphasizing the need for proactive antimicrobial management.</p>","PeriodicalId":54246,"journal":{"name":"Antibiotics-Basel","volume":"14 5","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12108305/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144163596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In Vitro Activity of Imipenem/Relebactam Alone and in Combination Against Cystic Fibrosis Isolates of <i>Mycobacterium abscessus</i>.","authors":"Madeline Sanders, Sun Woo Kim, Aditi Shinde, Danielle Fletcher-Williams, Eric Quach, Paul Beringer","doi":"10.3390/antibiotics14050486","DOIUrl":"10.3390/antibiotics14050486","url":null,"abstract":"<p><strong>Background: </strong><i>Mycobacterium abscessus</i> (MABS) is an opportunistic pathogen that causes chronic, difficult-to-treat pulmonary infections, particularly in people with cystic fibrosis (PwCF), leading to rapid lung function decline and increased morbidity and mortality. Treatment is particularly challenging due to the pathogen's resistance mechanisms and the need for prolonged multidrug therapy, which is characterized by poor clinical outcomes and highlights the urgent need for novel therapeutic strategies. Imipenem/relebactam, a novel β-lactam-β-lactamase inhibitor combination, demonstrates in vitro activity against resistant MABS strains and effective pulmonary penetration. Prior research indicates synergistic activity of imipenem with various antibiotics against <i>M. abscessus</i>.</p><p><strong>Objectives: </strong>This study aims to evaluate the in vitro activity of imipenem/relebactam, alone and in combination with various antibiotics, against MABS clinical isolates from PwCF (<i>n</i> = 28).</p><p><strong>Methods: </strong>Susceptibility and synergy were assessed using broth microdilution and checkerboard assays. Extracellular time-kill assays were performed to evaluate the bactericidal activity of synergistic three-drug combinations containing imipenem/relebactam.</p><p><strong>Results: </strong>Imipenem/relebactam demonstrated potent in vitro activity against clinical MABS isolates, exhibiting substantial synergy with cefuroxime, cefdinir, amoxicillin, and cefoxitin. Rifabutin, azithromycin, moxifloxacin, clofazimine, and minocycline also demonstrated additive effects with imipenem/relebactam. Extracellular time-kill assays identified imipenem/relebactam + cefoxitin + rifabutin and imipenem/relebactam + cefoxitin + moxifloxacin as the most effective combinations.</p><p><strong>Conclusions: </strong>These findings suggest that imipenem/relebactam may offer a significant advancement in the management of MABS infections in PwCF. The promising efficacy of multidrug regimens combining imipenem/relebactam with agents like cefoxitin, azithromycin, moxifloxacin, clofazimine, and rifabutin highlights potential therapeutic strategies.</p>","PeriodicalId":54246,"journal":{"name":"Antibiotics-Basel","volume":"14 5","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12108374/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144163431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Repurposing Mouthwashes: Antifungal and Antibiofilm Abilities of Commercially Available Mouthwashes Against <i>Candida</i> spp.","authors":"Marie Maziere, Paulo Rompante, José Carlos Andrade, Beatriz S F De Oliveira, Mariana C Alves, Celia Fortuna Rodrigues","doi":"10.3390/antibiotics14050483","DOIUrl":"10.3390/antibiotics14050483","url":null,"abstract":"<p><p><b>Background/Objectives</b>: The main objective was to evaluate and compare the antifungal efficacy against <i>Candida</i> spp. in commercially available mouthwashes distributed in the European market. Indeed, the solution to emerging infectious diseases may no longer lie in costly new drug development but rather in unlocking the untapped potential of existing substances. <b>Materials and Methods</b>: Eighteen mouthwashes, chosen based on their composition, were tested in vitro against ten <i>Candida</i> strains, including clinical isolates of oral origin and reference strains, in both planktonic and biofilm forms. The antifungal susceptibility testing was conducted using the European Committee on Antimicrobial Susceptibility Testing (EUCAST) disc diffusion method and the evaluation of the kinetic growth in planktonic <i>Candida</i>. Biofilm reduction was determined by the evaluation of the minimal biofilm eradication concentration (MBEC). Scanning electron microscopy (SEM) analysis was performed to evaluate potential morphological alterations of <i>Candida</i> biofilms. <b>Results</b>: Most mouthwashes effectively reduced biomass production and colony-forming unit (CFU) count. Parodontax Extra showed the highest efficacy. In the disc diffusion assay, Gum Paroex 0.12% exhibited the largest average inhibition zone diameter. Some unusual trends in the data may be explained by a higher reaction of fungal cells and the release of excess biomass during co-incubation in higher concentration of mouthwashes. SEM images revealed significant morphological alterations. <b>Conclusion</b>: Mouthwashes containing chlorhexidine digluconate, either alone or in combination with cetylpyridinium chloride and other active compounds, emerged as a common factor among the most efficacious formulations. In vivo studies will be essential to validate these findings, but mouthwashes may serve as a valuable adjuvant in the treatment of oral candidiasis.</p>","PeriodicalId":54246,"journal":{"name":"Antibiotics-Basel","volume":"14 5","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12108391/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144163453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Misconceptions and Behavioral Risks in Parental Antibiotic Use on Romanian Children: A Cross-Sectional Study on Knowledge, Attitudes, and Practices.","authors":"Alin Iuhas, Radu Galiș, Marius Rus, Andreea Balmoș, Cristian Marinău, Larisa Niulaș, Zsolt Futaki, Dorina Matioc, Cristian Sava","doi":"10.3390/antibiotics14050479","DOIUrl":"10.3390/antibiotics14050479","url":null,"abstract":"<p><strong>Background: </strong>Antimicrobial resistance is a growing global health threat, with antibiotic misuse in pediatric populations being a significant contributing factor. In Romania, antibiotic consumption and resistance rates are among the highest in Europe.</p><p><strong>Objective: </strong>To assess Romanian parents' knowledge, attitudes, and practices regarding antibiotic use in children, and to identify key misconceptions and behavioral risks contributing to inappropriate antibiotic use.</p><p><strong>Methods: </strong>A cross-sectional survey was conducted among 400 parents of hospitalized children in a pediatric department in Romania. Participants completed a 15 item structured questionnaire. Data were analyzed using descriptive statistics, chi-square tests, and binary logistic regression to examine associations and control for potential confounding effects between education level, residential environment, and parental misconceptions regarding antibiotic use.</p><p><strong>Results: </strong>Among the 400 surveyed caregivers, 86% (<i>n</i> = 344) held at least one misconception regarding antibiotic use. Additionally, 42.5% (<i>n</i> = 170) of participants reported that they had never heard of the concept of antibiotic resistance. Misconceptions were significantly more prevalent among individuals with lower levels of education and those residing in rural areas (<i>p</i> < 0.001). While 89.8% (<i>n</i> = 359) stated that they had never administered antibiotics to their children without a physician's recommendation, a separate subset of 28% (<i>n</i> = 112) acknowledged that they had asked a doctor to prescribe antibiotics for their child. Moreover, 23.3% (<i>n</i> = 93) reported seeking a second medical opinion when antibiotics were not initially prescribed.</p><p><strong>Conclusions: </strong>Despite high adherence to medical advice, widespread misconceptions persist. These findings highlight the need for targeted, population-specific educational interventions to promote rational antibiotic use and address AMR in high-burden settings like Romania.</p>","PeriodicalId":54246,"journal":{"name":"Antibiotics-Basel","volume":"14 5","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12108163/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144163695","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heterogeneity of Biofilm Formation Among <i>Staphylococcus aureus</i> and Coagulase-Negative <i>Staphylococcus</i> Species in Clinically Relevant Intravenous Fat Emulsions.","authors":"Gustavo R Alvira-Arill, Oscar R Herrera, Jeremy S Stultz, Brian M Peters","doi":"10.3390/antibiotics14050484","DOIUrl":"10.3390/antibiotics14050484","url":null,"abstract":"<p><p><b>Background</b>: Compared to soybean oil intravenous fat emulsion (SO-IFE), use of mixed-oil IFE (MO-IFE) is associated with reduced rates of catheter-related bloodstream infections caused by coagulase-negative <i>Staphylococcus</i> species (CoNS) in pediatric patients receiving parenteral nutrition. <b>Methods</b>: Using an in vitro biofilm model, this study aimed to assess the impact of IFEs on biofilm formation among <i>Staphylococcus</i> species. <i>S. aureus</i>, <i>S. capitis</i>, <i>S. epidermidis</i>, <i>S. haemolyticus</i>, <i>S. hominis</i>, and <i>S. lugdunensis</i> were cultivated as biofilms in media supplemented with SO-IFE, MO-IFE, or fish oil IFE (IFE). Biomass was quantified by the crystal violet method, and follow-up planktonic growth assays assessed antimicrobial effects of IFEs. <b>Results</b>: Compared to SO-IFE, MO-IFE and FO-IFE significantly inhibited biofilm formation of <i>S. aureus</i> but did not impact planktonic growth. Contrary to clinical data, CoNS biofilm formation was not impacted by any of the IFEs tested. <i>S. aureus</i> biofilm inhibition in IFEs was further investigated by comparing differences following growth in SO-IFE supplemented with capric acid, docosahexaenoic acid (DHA), or eicosapenaenoic acid (EPA) to concentrations matching those of MO-IFE. Capric acid supplementation was associated with significant reduction in biofilm formation compared to SO-IFE alone. However, this was attributed to a bactericidal effect based on follow-up planktonic growth assays. <b>Conclusions</b>: These results suggest that biofilm formation in <i>S. aureus</i> is variably impacted by fatty acid composition in clinically relevant IFEs, with capric acid exhibiting bactericidal activity against tested isolates.</p>","PeriodicalId":54246,"journal":{"name":"Antibiotics-Basel","volume":"14 5","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12108170/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144163349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phenotypic and Genotypic Characterization of ESBL-, AmpC-, and Carbapenemase-Producing <i>Klebsiella pneumoniae</i> and High-Risk <i>Escherichia coli</i> CC131, with the First Report of ST1193 as a Causative Agent of Urinary Tract Infections in Human Patients in Algeria.","authors":"Hajer Ziadi, Fadela Chougrani, Abderrahim Cheriguene, Leticia Carballeira, Vanesa García, Azucena Mora","doi":"10.3390/antibiotics14050485","DOIUrl":"10.3390/antibiotics14050485","url":null,"abstract":"<p><strong>Background: </strong>High-risk <i>Escherichia coli</i> clones, such as sequence type (ST)131 and ST1193, along with multidrug-resistant (MDR) <i>Klebsiella pneumoniae</i>, are globally recognized for their significant role in urinary tract infections (UTIs). This study aimed to provide an overview of the virulence factors, clonal diversity, and antibiotic resistance profiles of extended-spectrum cephalosporin (ESC)-<i>E. coli</i> and <i>K. pneumoniae</i> causing UTIs in humans in the Tebessa region of Algeria.</p><p><strong>Methods: </strong>Forty <i>E. coli</i> and 17 <i>K. pneumoniae</i> isolates exhibiting ESC-resistance were recovered (July 2022-January 2024) from urine samples of patients at three healthcare facilities to be phenotypically and genotypically characterized. Whole genome sequencing (WGS) was performed on the ST1193 clone.</p><p><strong>Results: </strong>Among <i>K. pneumoniae</i> isolates, all except one harbored CTX-M-15, with a single isolate carrying <i>bla</i>_CTX-M-194. Additionally, two <i>K. pneumoniae</i> isolates co-harboring <i>bla</i>_CTX-M-15 and <i>bla</i>_NDM exhibited phenotypic and genotypic hypervirulence traits. Fluoroquinolone resistance (FQR) was detected in 94.1% of <i>K. pneumoniae</i> isolates. The <i>E. coli</i> isolates carried diverse ESC-resistance genes, including CTX-M-15 (87.5%), CTX-M-27 (5%), CTX-M-1, CMY-59, and CMY-166 (2.5% each). Co-carriage of <i>bla</i>_ESC and <i>bla</i>_OXA-48 was identified in three <i>E. coli</i> isolates, while 62.5% exhibited FQR. Phylogenetic analysis revealed that 52.5% of <i>E. coli</i> belonged to phylogroup B2, including the high-risk clonal complex (CC)131 CH40-30 (17 isolates) and ST1193 (one isolate). In silico analysis of the ST1193 genome determined O75:H5-B2 (CH14-64), and the carriage of IncI1-I(Alpha) and IncF [F-:A1:B10] plasmids. Notably, core genome single-nucleotide polymorphism (SNP) analysis demonstrated high similarity between the Algerian ST1193 isolate and a previously annotated genome from a hospital in Northwest Spain.</p><p><strong>Conclusions: </strong>This study highlights the spread and genetic diversity of <i>E. coli</i> CC131 CH40-30 and hypervirulent <i>K. pneumoniae</i> clones in Algeria. It represents the first report of a CTX-M-15-carrying <i>E. coli</i> ST1193 in the region. The findings emphasize the urgent need for antibiotic optimization programs and enhanced surveillance to curb the dissemination of high-risk clones that pose an increasing public health threat in Algeria. A simplified method based on virulence traits for <i>E. coli</i> and <i>K. pneumoniae</i> is proposed here for antimicrobial resistance (AMR) monitoring.</p>","PeriodicalId":54246,"journal":{"name":"Antibiotics-Basel","volume":"14 5","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12108494/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144163621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prevalence and Antimicrobial Resistance of <i>Listeria monocytogenes</i> Isolated from Dairy Products in Romania.","authors":"Filippos Georgios Nikolaou, Liora Mihaela Colobatiu, Laurentiu Mihai Ciupescu, Alexandra Tabaran, Ariana Raluca Hategan, Romolica Mihaiu, Radu Tanasuica, Magdalena Maria Poenaru, Marian Mihaiu","doi":"10.3390/antibiotics14050482","DOIUrl":"10.3390/antibiotics14050482","url":null,"abstract":"<p><p><b>Background/Objectives:</b><i>Listeria monocytogenes</i> is a significant foodborne pathogen associated with dairy products, which can pose serious public health risks, particularly for vulnerable populations. This study aimed to assess the prevalence, serotype distribution, and antimicrobial resistance profiles of <i>Listeria monocytogenes</i> isolated from dairy products collected in Romania over a three-year period (2021-2023). To the best of our knowledge, this is the first comprehensive study addressing these issues within the country. <b>Methods</b>: A total of 10,306 dairy samples, including milk, cheeses, ice cream, yogurt, and other dairy-based products, were collected and analyzed using standard microbiological methods. Molecular serotyping was performed to identify the most common serogroups. The antimicrobial susceptibility of the isolates was also conducted. <b>Results</b>: The overall prevalence of <i>Listeria monocytogenes</i> was 0.41% (43/10,306). The most frequently detected serogroup was IVb (74.41%), followed by IIa (23.25%) and IIb (2.32%). Ice cream was the most affected product, followed by fresh telemea made from cow milk. Antimicrobial susceptibility testing revealed higher resistance rates for oxacillin and trimethoprim-sulfamethoxazole (13.95% each), while all isolates were susceptible to ciprofloxacin, levofloxacin, and moxifloxacin. <b>Conclusions</b>: The findings emphasize the need for continuous monitoring of <i>Listeria monocytogenes</i> in dairy products, particularly ice cream and fresh cheeses, due to their high contamination rates. The study's results are valuable for comparative analysis with findings from other countries, helping to establish a broader understanding of <i>Listeria monocytogenes</i> contamination trends and resistance profiles.</p>","PeriodicalId":54246,"journal":{"name":"Antibiotics-Basel","volume":"14 5","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12108530/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144163624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pulsed Blue Light and Phage Therapy: A Novel Synergistic Bactericide.","authors":"Amit Rimon, Jonathan Belin, Ortal Yerushalmy, Yonatan Eavri, Anatoly Shapochnikov, Shunit Coppenhagen-Glazer, Ronen Hazan, Lilach Gavish","doi":"10.3390/antibiotics14050481","DOIUrl":"10.3390/antibiotics14050481","url":null,"abstract":"<p><p><b>Background:</b> Antibiotic-resistant <i>Pseudomonas aeruginosa</i> (<i>P. aeruginosa</i>) 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 <i>P. aeruginosa</i> in planktonic cultures and preformed biofilms. <b>Methods:</b> We conducted a factorial dose-response in vitro study combining <i>P. aeruginosa-specific</i> 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 <i>growth_curve_outcomes</i>, 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 (<i>n</i> = 5 biological replicates and technical triplicates). <b>Results:</b> The bacterial growth lag phase was significantly extended for phage alone or PBL alone, with a synergistic effect of up to 144% (<i>p</i> < 0.001 for all), achieving a 9 log CFU/mL reduction at 24 h (<i>p</i> < 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%, <i>p</i> < 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. <b>Conclusions:</b> Phage therapy combined with PBL demonstrates a synergistic bactericidal effect against <i>P. aeruginosa</i> 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.</p>","PeriodicalId":54246,"journal":{"name":"Antibiotics-Basel","volume":"14 5","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12108478/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144163251","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Selective Chromogenic Medium for Detecting Meropenem-Resistant <i>Pseudomonas aeruginosa</i> in Respiratory Samples.","authors":"Carmen Cintora Mairal, Guillermo Martín-Gutiérrez, Ángel Rodríguez-Villodres, José Miguel Cisneros, José Antonio Lepe, José Manuel Ortiz de la Rosa","doi":"10.3390/antibiotics14050480","DOIUrl":"10.3390/antibiotics14050480","url":null,"abstract":"<p><p><b>Background/Objectives</b>: Meropenem is widely used to treat Pseudomonas aeruginosa infections; however, the pathogen's increasing resistance compromises its efficacy. In this study, we aimed to develop a selective culture medium for detecting the presence of meropenem-resistant <i>Pseudomonas aeruginosa</i> in respiratory specimens within 24 h. <b>Methods</b>: The medium's performance was challenged using a collection of 130 clinical <i>Pseudomonas aeruginosa</i> strains (of which 85 were meropenem-susceptible, 14 were meropenem-intermediate, and 21 were meropenem-resistant). Subsequently, clinical validation was carried out using 130 respiratory samples. <b>Results</b>: The selective medium demonstrated excellent sensitivity (average 98.7%) and specificity (average 90%) across bacterial concentrations ranging from 1 × 10⁴ to 1 × 10⁸ CFU/mL, and a high negative predictive value (average 99.2%) compared to the broth microdilution (BMD) method. Clinical validation with bronchoalveolar lavage (BAL) and tracheobronchial aspirate (TBA) clinical specimens (N = 130) revealed a strong performance, with 92,3% categorical agreement. <b>Conclusions</b>: This method accelerates susceptibility testing, is user-friendly, and delivers reliable results, contributing to the optimization of empirical treatment for respiratory tract infections.</p>","PeriodicalId":54246,"journal":{"name":"Antibiotics-Basel","volume":"14 5","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12108385/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144163623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}