Antibiotics-Basel最新文献

{"title":"Catheter Duration Threshold and Risk Factors for Central Line-Associated Bloodstream Infections in a Tertiary ICU with Endemic Carbapenem Resistance: A Case-Control Study.","authors":"Enes Dalmanoğlu, Mehmet Özgür Özhan, Bülent Atik, Tülin Akarsu Ayazoğlu","doi":"10.3390/antibiotics15040407","DOIUrl":"https://doi.org/10.3390/antibiotics15040407","url":null,"abstract":"<p><p><b>Background/Objectives:</b> Central line-associated bloodstream infections (CLABSIs) remain a leading healthcare-associated infection in intensive care units (ICUs), yet independent risk factors and evidence-based catheter duration thresholds have not been defined through analytical study designs in settings with endemic multidrug-resistant organisms (MDROs). <b>Methods:</b> A retrospective case-control study was conducted in the ICU of a tertiary teaching university hospital in western Türkiye (January 2019-December 2024). Cases (n = 74) were patients with confirmed CLABSIs per CDC/NHSN criteria; controls (n = 148) were randomly selected central venous catheter (CVC)-bearing patients without CLABSIs. A reduced multivariate logistic regression model (seven variables; events-per-variable ratio 10.6) identified independent risk factors. <b>Results:</b> In multivariate analysis, catheter duration (adjusted OR: 1.19 per day; 95% CI: 1.13-1.24; <i>p</i> < 0.001), renal replacement therapy (aOR: 3.66; 95% CI: 1.68-7.95; <i>p</i> = 0.001), vasopressor support (aOR: 3.04; 95% CI: 1.50-6.17; <i>p</i> = 0.002), APACHE-II score (aOR: 1.07 per point; 95% CI: 1.02-1.11; <i>p</i> = 0.002), lower Glasgow Coma Scale (aOR: 0.86 per point; 95% CI: 0.78-0.94; <i>p</i> = 0.002), mechanical ventilation (aOR: 2.48; 95% CI: 1.24-4.95; <i>p</i> = 0.010), and total parenteral nutrition (aOR: 2.33; 95% CI: 1.12-4.86; <i>p</i> = 0.024) were independently associated with CLABSI. The model demonstrated good discrimination (C-statistic: 0.864) and calibration (Hosmer-Lemeshow <i>p</i> = 0.425). Kaplan-Meier analysis showed CLABSI-free survival declining from 98.9% at day 7 to 42.9% at day 21 (log-rank <i>p</i> < 0.001); these within-study estimates reflect relative risk patterns given the artificial 1:2 case-to-control ratio. Receiver operating characteristic (ROC) analysis identified day 13 as an exploratory optimal cutoff (AUC: 0.818; 95% CI: 0.762-0.874; sensitivity: 77.0%; specificity: 74.3%). CLABSI-attributable ICU mortality was 20.3% (47.3% vs. 27.0%; <i>p</i> = 0.004). Late-onset CLABSIs (>10 days) were dominated by Gram-negative pathogens (68.3%) versus 35.7% in early-onset infections (Fisher's exact <i>p</i> = 0.012), with <i>Acinetobacter baumannii</i> as the predominant organism (27.0%; 83.3% carbapenem-resistant). <b>Conclusions:</b> Each additional catheter-day is independently associated with a 19% increment in CLABSI odds, with an exploratory critical threshold at day 13 beyond which enhanced surveillance measures should be considered, pending external validation.</p>","PeriodicalId":54246,"journal":{"name":"Antibiotics-Basel","volume":"15 4","pages":""},"PeriodicalIF":4.6,"publicationDate":"2026-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13113509/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147789075","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":"Mechanistic Insights into the Anti-Virulence Effects of <i>Viroelixir</i>, a Phenolic Blend from Green Tea and Pomegranate, on <i>Streptococcus mutans</i>.","authors":"Manal Dahdah, Vijaykumar D Nimbarte, Mahmoud Rouabhia, Yasmine Ettouil, Hawraa Issa, Latifa Koussih, Mikhlid H Almutairi, Abdelhabib Semlali","doi":"10.3390/antibiotics15040406","DOIUrl":"https://doi.org/10.3390/antibiotics15040406","url":null,"abstract":"<p><p><b>Background</b>: Dental caries remains one of the most prevalent oral diseases worldwide, largely driven by the virulence of <i>Streptococcus mutans</i>. Although plant phenolics from green tea and pomegranate are known for their antimicrobial properties, their molecular mechanisms of action against key <i>S. mutans</i> virulence targets remain insufficiently characterized. <b>Aim</b>: This study investigated the antibacterial and anti-virulence properties of <i>Viroelixir</i>, a phenolic-rich formulation derived from green tea (<i>Camellia sinensis</i>) and pomegranate (<i>Punica granatum</i>), against <i>S. mutans</i>, with particular emphasis on predictive molecular docking interactions with critical virulence-associated proteins. <b>Methods</b>: <i>Viroelixir</i> phytochemical composition was characterized by LC-MS using a C18 reverse-phase column and negative electrospray ionization mode. Antibacterial activity was evaluated using growth kinetics, agar plating, and crystal violet assays. Acidogenicity, hemolytic activity, and biofilm formation were assessed using pH modulation, hemolysis assays, SEM, and biofilm biomass quantification. Virulence gene expression was analyzed by RT-qPCR. In silico molecular docking was performed to explore potential interactions between major LC-MS-supported phenolic constituents and <i>S. mutans</i> virulence proteins, including glucosyltransferase B (GtfB), LuxS, and SpaP. Biocompatibility was evaluated in human gingival epithelial cells. <b>Results</b>: The LC-MS analysis revealed a complex mixture of phenolic compounds consistent with catechins and ellagitannins. Compound identification was considered tentative and based on mass spectral range and chromatographic behavior. <i>Viroelixir</i> significantly inhibited <i>S. mutans</i> growth, acid production, hemolytic activity, and biofilm formation in a concentration-dependent manner. Key virulence genes were markedly downregulated. Docking analyses suggested stable binding of selected phenolics-particularly punicalagin, catechin, and epigallocatechin-within the active sites of <i>GtfB</i>, <i>LuxS</i>, and <i>SpaP</i>. Importantly, <i>Viroelixir</i> showed no cytotoxic effects on gingival epithelial cells. <b>Conclusions</b>: <i>Viroelixir</i> exerts potent antibacterial and anti-virulence effects against <i>S. mutans</i> through a multi-target mechanism combining transcriptional suppression and predictive molecular inhibition of virulence proteins, supporting its potential as a safe, natural therapeutic for caries prevention.</p>","PeriodicalId":54246,"journal":{"name":"Antibiotics-Basel","volume":"15 4","pages":""},"PeriodicalIF":4.6,"publicationDate":"2026-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13113439/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147789125","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":"Antibiotics and Other Drugs Removal by the CytoSorb^® Haemoadsorber: A Systematic Review of Available Evidence.","authors":"Sara Kenda, Jakob Gubenšek, Tomaž Vovk","doi":"10.3390/antibiotics15040409","DOIUrl":"https://doi.org/10.3390/antibiotics15040409","url":null,"abstract":"<p><p><b>Background/Objectives</b>: Haemoadsorption has recently emerged as an extracorporeal treatment option for sepsis, septic shock, intoxications, and cardiac surgery to modulate dysregulated inflammatory responses or remove a wide range of circulating molecules. To ensure appropriate clinical use of the CytoSorb^® haemoadsorber, it is essential to understand the extent to which specific drugs are adsorbed by the device. <b>Methods</b>: We conducted a systematic literature review using the PubMed and Ovid MEDLINE database to identify studies on drug binding to the CytoSorb^® haemoadsorber, including both in vivo and in vitro studies. Publications in English language, available up to 31 December 2025 that reported or enabled calculation of percentage of drug removal, CytoSorb^® clearance or half-life during CytoSorb^® therapy were included. Records were screened, eligibility and quality were assessed, and data were extracted independently by two reviewers. <b>Results</b>: We found that 26 studies reported on the binding of 56 drugs to CytoSorb^®, with most available information relating to antibiotics used in the treatment of sepsis and septic shock. CytoSorb^® appears to remove vancomycin and linezolid but not meropenem, although data for other antibiotics are insufficient to assess clinical relevance. Data on the removal of anticoagulant and antithrombotic drugs with CytoSorb^® before and during cardiac surgery indicate that using this procedure to reduce complications associated with apixaban and ticagrelor is feasible and safe. The available evidence on the use of CytoSorb^® for drug poisoning is of very low quality. <b>Conclusions</b>: Although the number of studies on drug binding to the CytoSorb^® is increasing, the review is limited by the marked heterogeneity among the included studies. It is advised to use therapeutic drug monitoring whenever possible during CytoSorb^® treatment. Research of binding of drugs to CytoSorb^® is crucial for its safe and effective clinical use, but adequate methodology is necessary.</p>","PeriodicalId":54246,"journal":{"name":"Antibiotics-Basel","volume":"15 4","pages":""},"PeriodicalIF":4.6,"publicationDate":"2026-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13113826/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147789203","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":"Genomic Epidemiology of ESBL and Non-ESBL-Producing <i>Escherichia coli</i> Across One Health Interfaces in Oman.","authors":"Hibatallah Sultan Al-Habsi, Zaaima Al Jabri, Amina Al-Jardani, Amira ElBaradei, Hafidha Al-Hattali, Faiza Syed, Zakariya Al Muharrmi, Wafa Al Alawi, Hatim Ali Eltahir, Meher Rizvi","doi":"10.3390/antibiotics15040411","DOIUrl":"https://doi.org/10.3390/antibiotics15040411","url":null,"abstract":"<p><p><b>Background</b>: Antimicrobial resistance is a One Health problem driven by the intricate interactions across human, animal, and environmental interfaces that enable microbial exchange and movement of mobile genetic elements encoding resistance and virulence. This study investigated the genomic epidemiology of ESBL and non-ESBL <i>Escherichia coli</i> across One Health interfaces in Oman. <b>Methods</b>: This prospective cross-sectional study analyzed 295 non-duplicate <i>Escherichia coli</i> isolates derived from 104 clinical, 173 animal [diseased (123) and healthy (50)], 14 sewage and four water sources. Antimicrobial susceptibility testing was performed phenotypically, and a representative subset of 50 ESBL and non-ESBL <i>Escherichia coli</i> from the three interfaces underwent whole genome sequencing to determine MLST, phylogroups, resistance genes, virulence determinants and plasmid replicons. <b>Results</b>: ESBL prevalence was highest in human isolates (73%), followed by sewage (28.6%) and animals (16.3% diseased; 8% healthy). <i>bla</i>CTX-M-15 predominated in humans, whereas <i>bla</i>CTX-M-55 dominated in animals and sewage, suggesting ecological partitioning with partial overlap. Quinolone resistance was lowest in the animal interface. Sewage isolates harbored the most complex resistome, including <i>rmtB</i> and plasmid-mediated quinolone resistance genes. MLST analysis revealed high diversity in human isolates, including globally recognized ExPEC lineages (ST10, ST38, ST73, ST127, ST131), while ST224 dominated in animals with evidence of possible spillover to humans. ST167 was confined to sewage, consistent with environmental maintenance of high-risk clones. Phylogroup structuring showed predominance of A, B2 and D among human isolates and A, B1, and E among animal and sewage isolates. Virulence profiling demonstrated broader virulome diversity in humans, but shared core determinants (<i>fimH</i>, <i>sitA</i>, <i>traT</i>) across all domains. IncFIB(AP001918) was the dominant plasmid replicon, particularly among ESBL isolates, underscoring its role in horizontal gene dissemination. Alarmingly, mutation in <i>pmrB</i> (V161G) was identified in a healthy animal isolate, pointing to a need for greater colistin restriction in animal husbandry. <b>Conclusions</b>: This study highlights plasmid-mediated resistance and shared virulence determinants linking reservoirs; although AMR profile was quite distinct across the three interfaces, human isolates demonstrated greater resistance than animal isolates, suggesting healthcare-driven AMR in Oman. Continued integrated genomic surveillance is essential to monitor gene flow and inform coordinated antimicrobial stewardship strategies.</p>","PeriodicalId":54246,"journal":{"name":"Antibiotics-Basel","volume":"15 4","pages":""},"PeriodicalIF":4.6,"publicationDate":"2026-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13114006/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147789226","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":"Membrane-Focused Strategies Against <i>Acinetobacter baumannii</i>: The Therapeutic Potential of Functional Copolymers.","authors":"Barbara Cardoso Domingues, Marc Maresca, Jean-Michel Bolla, Véronique Sinou","doi":"10.3390/antibiotics15040408","DOIUrl":"https://doi.org/10.3390/antibiotics15040408","url":null,"abstract":"<p><p>Antimicrobial resistance is a serious global public health concern, with <i>Acinetobacter baumannii</i> recognized as one of the most problematic multidrug-resistant (MDR) pathogens. This Gram-negative bacterium is highly persistent in the environment, possesses a remarkably adaptable cell envelope, and forms biofilms. As the effectiveness of conventional antibiotics declines, alternative strategies are being actively explored, particularly membrane-targeting approaches based on synthetic copolymers. These compounds mimic antimicrobial peptides, offer enhanced stability and structural tunability, and have a lower propensity to develop resistance. Recent advances in polymer chemistry have led to the design of antibacterial polymers with activity against MDR <i>A. baumannii</i>. Some of these act synergistically with existing antibiotics, restoring bacterial susceptibility or disrupting biofilms. However, their non-degradability remains a concern due to its potential implications for body/environment accumulation and related toxicity and/or selection of resistant strains. This review examines the biology of the <i>A. baumannii</i> cell envelope, its resistance mechanisms, and treatment limitations, while emphasizing the promise of membrane-active copolymers. By bridging materials science and microbiology, these approaches offer promising strategies for combating World Health Organization priority pathogens.</p>","PeriodicalId":54246,"journal":{"name":"Antibiotics-Basel","volume":"15 4","pages":""},"PeriodicalIF":4.6,"publicationDate":"2026-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13113831/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147789173","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":"Albumin Nanoparticles Improve Colistin Performance Against Hetero- and Full-Resistant Clinical <i>A. baumannii</i>: A Mechanistic Study.","authors":"Sara Scutera, Viviana Cafiso, Giulia Vigna, Monica Argenziano, Eleonora Chines, Antonio Curtoni, Matteo Florio Furno, Giovanna Cristina Varese, Chiara Scarpa, Ilario Ferrocino, Stefania Raimondo, Gabriele Bianco, Roberta Cavalli, Tiziana Musso","doi":"10.3390/antibiotics15040410","DOIUrl":"https://doi.org/10.3390/antibiotics15040410","url":null,"abstract":"<p><p><b>Background:</b> Colistin (Col) resistance and heteroresistance in extensively drug-resistant (XDR) <i>Acinetobacter baumannii</i> severely limit therapeutic options. We investigated the activity and mechanism of human albumin nanoparticles (haNPs) as colistin potentiators against genetically characterized clinical isolates. <b>Methods:</b> Sixteen clinical isolates were analyzed. Col MICs were determined by broth microdilution, and heteroresistance by population analysis profiling. Potentiation of Col activity was assessed using both Col-loaded haNPs (Col/haNPs) and free Col co-administered with empty haNPs, alongside the proton motive force (PMF) uncoupler carbonyl cyanide 3-chlorophenylhydrazone (CCCP). Assays included checkerboard synergy (FICI), membrane potential analysis (DiOC₂(3)), intracellular Col quantification (UPLC-MS/MS), zeta potential measurements, transmission electron microscopy (TEM), protein leakage, and ROS detection. <b>Results:</b> Heteroresistance was detected in 9/16 isolates. Col/haNPs reduced Col MICs by 4-64-fold in resistant strains and shifted MICs to ≤2 mg/L in most heteroresistant isolates. Empty haNPs displayed no intrinsic antibacterial activity yet selectively potentiated Col, with strong synergy (FICI down to 0.035). Membrane depolarization and increased intracellular Col accumulation under haNP-treated conditions paralleled the effects of CCCP, indicating that haNPs elicit a CCCP-like functional response. These findings are compatible with perturbation of membrane energetics and possible downstream effects on PMF-dependent transport processes. TEM and surface charge analyses supported direct nanoparticle-envelope interaction and progressive membrane disruption. <b>Conclusions:</b> haNPs enhance Col activity across genetically diverse <i>A. baumannii</i> isolates, with particularly strong effects in heteroresistant strains. The combined effects of PMF modulation, increased intracellular drug availability, and envelope interaction provide a mechanistic rationale for the use of albumin-based nanoparticles, either as Col carriers or in combination with free drug, to overcome Col resistance and heteroresistance.</p>","PeriodicalId":54246,"journal":{"name":"Antibiotics-Basel","volume":"15 4","pages":""},"PeriodicalIF":4.6,"publicationDate":"2026-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13114173/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147789207","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 Antifungal Activity of Essential Oils and Nanoemulsions of <i>Zingiber cassumunar</i> and <i>Cymbopogon citratus</i> Against Planktonic and Biofilm Forms of <i>Malassezia pachydermatis</i>.","authors":"Sirikorn Promcham, Orawan Limsivilai, Theerawat Kritsadasima, Suttiwee Chermprapai, Natthasit Tansakul, Pareeya Udomkusonsri, Chompoonek Yurayart","doi":"10.3390/antibiotics15040402","DOIUrl":"https://doi.org/10.3390/antibiotics15040402","url":null,"abstract":"<p><p><i>Malassezia pachydermatis</i> is a yeast pathogen associated with recurrent skin and ear infections in dogs, often complicated by biofilm formation and reduced antifungal susceptibility. We aimed to evaluate the in vitro antifungal activity of essential oils and nanoemulsions of <i>Zingiber cassumunar</i> and <i>Cymbopogon citratus</i> compared with conventional antifungal agents against planktonic and biofilm forms of <i>M. pachydermatis</i>. Preliminary screening of six plant extracts was performed using 12 clinical isolates identified <i>Z. cassumunar</i> and <i>C. citratus</i> for nanoemulsion formulation. Antifungal susceptibility testing of conventional antifungal agents and nanoemulsions was subsequently conducted using 31 clinical isolates, and nanoemulsions were prepared by high-pressure homogenization. Both essential oils exhibited antifungal activity, and nanoemulsion formulations showed enhanced inhibitory effects compared with the crude oils. Biofilm-associated cells demonstrated reduced susceptibility, particularly to conventional antifungal agents. Terbinafine was the most potent agent against planktonic cells but showed reduced efficacy in biofilms. Nanoemulsions of <i>Z. cassumunar</i> and <i>C. citratus</i> exhibited improved activity against both forms. These findings suggest that nanoemulsification may enhance the in vitro antifungal performance of essential oils against <i>M. pachydermatis</i> biofilms. However, further studies, including mechanistic investigations and in vivo evaluations, are required to confirm their therapeutic potential and safety.</p>","PeriodicalId":54246,"journal":{"name":"Antibiotics-Basel","volume":"15 4","pages":""},"PeriodicalIF":4.6,"publicationDate":"2026-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13113068/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147788773","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":"Genomic and GWAS-Based Insights into Antimicrobial Resistance in <i>Shewanella algae</i> Isolated from <i>Penaeus monodon</i>.","authors":"Ponsit Sathapondecha, Wichai Pornthanakasem, Timpika Thepsuwan, Pacharaporn Angthong, Wiyada Chumpol, Kamonwan Lunha, Suganya Yongkiettrakul, Wanilada Rungrassamee","doi":"10.3390/antibiotics15040405","DOIUrl":"https://doi.org/10.3390/antibiotics15040405","url":null,"abstract":"<p><p><b>Background/Objectives:</b> The emergence of antimicrobial-resistant (AMR) pathogens in aquaculture ecosystems poses a significant risk to both food security and human health. <i>Shewanella</i> species are recognized as significant AMR reservoirs, yet their prevalence and resistance mechanisms within a shrimp-related ecosystem remain poorly characterized. This study aimed to perform a genotypic and phenotypic characterization of <i>S. algae</i> VK101, isolated from wild-caught black tiger shrimp (<i>Penaeus monodon</i>) broodstock. <b>Methods:</b> A complete 5.21 Mb genome was generated using a hybrid Illumina and Oxford Nanopore sequencing approach. Antimicrobial susceptibility was evaluated for 21 antibiotics via Minimum Inhibitory Concentration (MIC) testing. Comparative pangenomics and genome-wide association studies (GWAS) across 125 <i>S. algae</i> genomes were conducted to identify novel resistance determinants. <b>Results:</b> MIC analysis revealed that VK101 was resistant to ampicillin (>16 µg/mL) and colistin (8 µg/mL), while showing intermediate susceptibility to imipenem and ciprofloxacin. In silico analysis identified 205 antimicrobial resistance genes (ARGs), including a perfect hit for the fluoroquinolone resistance gene <i>qnrA3</i>. Notably, no <i>mcr</i> genes were detected. Although VK101 exhibited moderate resistance (8 µg/mL), GWAS across the broader <i>S. algae</i> population linked a specific <i>lptA</i> mutation (K140N) to high-level resistance (64 µg/mL). Other GWAS-identified genes (e.g., <i>czcA</i>, <i>ampC</i>, and <i>oprM</i>) likely represent indirect associations driven by genetic linkage or clade-specific markers rather than direct causal factors. <b>Conclusions:</b> These findings highlighted the presence of multidrug-resistant <i>S. algae</i> in wild-caught <i>P. monodon</i> broodstock, reflecting the occurrence of antimicrobial resistance in aquatic environments. Colistin resistance in these isolates was primarily mediated by chromosomal variants rather than mobile <i>mcr</i> elements, indicating the need for integrated genomic surveillance within the aquaculture value chain.</p>","PeriodicalId":54246,"journal":{"name":"Antibiotics-Basel","volume":"15 4","pages":""},"PeriodicalIF":4.6,"publicationDate":"2026-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13113632/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147789167","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":"Antibiotic Adjuvant Potential of Selected Essential Oil Components Against Respiratory Pathogens: From Planktonic Synergy to Early-Stage Biofilm Inhibition.","authors":"Viktória Lilla Balázs, Rita Filep, Edit Ormai, Lilla Radványi, Béla Kocsis, Erika Kerekes, Marianna Kocsis","doi":"10.3390/antibiotics15040403","DOIUrl":"https://doi.org/10.3390/antibiotics15040403","url":null,"abstract":"<p><p><b>Background:</b> Respiratory tract infections remain among the most common indications for antibiotic therapy and represent a major driver of antimicrobial resistance. The ability of respiratory pathogens to form biofilms further contributes to treatment failure and recurrence. This study aimed to evaluate the antibiotic adjuvant potential of selected essential oil components against clinically relevant respiratory bacteria and to determine whether planktonic synergistic interactions translate into early-stage antibiofilm efficacy. Thymol, eugenol, trans-cinnamaldehyde, and terpinen-4-ol were tested against <i>Streptococcus pneumoniae</i>, <i>Streptococcus pyogenes</i>, <i>Haemophilus influenzae</i>, <i>Haemophilus parainfluenzae</i>, <i>Moraxella catarrhalis</i>, methicillin-resistant <i>Staphylococcus aureus</i> (MRSA), and <i>Pseudomonas aeruginosa</i>. <b>Methods:</b> Minimum inhibitory concentrations were determined by broth microdilution. Synergistic interactions with clinically relevant antibiotics were assessed using the checkerboard method and fractional inhibitory concentration index (FICI) analysis. Selected combinations were further evaluated in a 6 h crystal violet-based early-stage biofilm model. Gram-positive strains generally exhibited higher susceptibility to the tested components than Gram-negative bacteria. <b>Results:</b> Synergistic interactions (FICI ≤ 0.5) were most frequently observed between β-lactam antibiotics and phenolic components, particularly thymol and trans-cinnamaldehyde. Strong synergy was detected for vancomycin-eugenol against MRSA and for amoxicillin/clavulanic acid-cinnamaldehyde against <i>M. catarrhalis</i>. Importantly, synergistic combinations translated into significantly enhanced inhibition of early biofilm formation, increasing inhibition rates by 15-40% compared to antibiotic monotherapy (<i>p</i> < 0.05). Selected essential oil components enhanced the antibacterial activity of clinically relevant antibiotics and effectively potentiated early-stage biofilm inhibition. <b>Conclusions:</b> These findings support further investigation of phytochemical-antibiotic combinations as potential adjunct strategies in respiratory infection management.</p>","PeriodicalId":54246,"journal":{"name":"Antibiotics-Basel","volume":"15 4","pages":""},"PeriodicalIF":4.6,"publicationDate":"2026-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13113440/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147789170","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 Performance Evaluation of the Vitek^®2 AST-N440 Card for Colistin Susceptibility Testing of Carbapenem-Resistant <i>Acinetobacter baumannii</i> Complex Isolates Using Broth Microdilution as the Reference Method.","authors":"Dimitra Petropoulou, Anastasios Ioannidis, Christina Kaminioti, Christina Mparka, Evgenia Mitropoulou, Georgia Petropoulou, Polyxeni Karakosta, Georgios Alexandros Baziotis, Spyros Pournaras","doi":"10.3390/antibiotics15040404","DOIUrl":"https://doi.org/10.3390/antibiotics15040404","url":null,"abstract":"<p><p><b>Background/Objectives:</b> Accurate determination of colistin (COL) in vitro activity against carbapenem-resistant <i>Acinetobacter baumannii</i> complex (CRAB) isolates remains challenging, as the reference broth microdilution (BMD) method is labor-intensive and not routinely implemented in most clinical laboratories. Semi-automated susceptibility methods for colistin in the clinical laboratory require validation. The present study evaluated the performance characteristics of the recently introduced Vitek^®2 card AST-N440 for COL antimicrobial susceptibility testing (AST) on CRAB isolates compared with a BMD-based reference method (ComASP Colistin). <b>Methods:</b> A total of 176 single-patient CRAB isolates from two distinct tertiary Greek hospitals between 2024 and 2025 were included. COL susceptibility testing was performed using Vitek^®2 AST-N440 and compared with BMD. Minimum inhibitory concentrations (MICs) were interpreted according to EUCAST breakpoints. Method performance was evaluated by calculating categorical (CA) and essential agreement (EA), sensitivity, specificity, positive and negative predictive values (PPV/NPV), and major (ME) and very major error rates (VME) according to ISO 20776-2. <b>Results:</b> Compared with BMD, AST-N440 showed a sensitivity of 89.6% and a specificity of 62.3%, with a PPV and NPV of 81.7% and 76.0%, respectively. The CA (80.1%) and the EA (46.0%) were below ISO acceptance criteria. The VME rate was 10.4%, and the ME rate 37.7%. Identical MIC values were observed in 25.0% of the isolates, while Vitek^®2 reported lower and higher MIC values than BMD in 46.6% and 28.4% of isolates, respectively. <b>Conclusions:</b> The Vitek^®2 AST-N440 card performed suboptimally for COL susceptibility testing in CRAB isolates. Further validation of automated systems for COL AST is needed.</p>","PeriodicalId":54246,"journal":{"name":"Antibiotics-Basel","volume":"15 4","pages":""},"PeriodicalIF":4.6,"publicationDate":"2026-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13113532/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147789182","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}