{"title":"Evaluation of Antimicrobial Activity of Novel Chimeric M-PEX12 Peptide Against <i>Acinetobacter baumannii</i>.","authors":"Yasin Rakhshani, Hamideh Mahmoodzadeh Hosseini, Seyed Ali Mirhosseini, Fatah Sotoodehnejadnematalahi, Jafar Amani","doi":"10.5812/ijpr-154484","DOIUrl":null,"url":null,"abstract":"<p><strong>Background: </strong><i>Acinetobacter baumannii</i>-induced nosocomial pneumonia and its associated biofilm infections pose significant clinical challenges due to high rates of antibiotic resistance. Traditional antibiotic treatments encounter numerous obstacles, making antimicrobial peptides (AMPs) a promising alternative for controlling such pathogens. The emergence of multidrug-resistant strains necessitates the exploration of innovative therapeutic strategies.</p><p><strong>Objectives: </strong>We recently designed a novel hybrid peptide, M-PEX12, which exhibits antimicrobial activity and low toxicity in vitro. To confirm its therapeutic potential, we evaluated it in both in vitro and in vivo settings.</p><p><strong>Methods: </strong>M-PEX12 was evaluated using time-kill kinetics, thermal stability, reactive oxygen species (ROS) generation, biofilm inhibition assays, scanning electron microscopy (SEM), cytotoxicity tests, and virulence gene expression analysis. Its in vivo activity against <i>A. baumannii</i> was also assessed in an animal model.</p><p><strong>Results: </strong>The time-kill kinetics assay indicated that exposure to M-PEX12 at 1x minimum inhibitory concentration (MIC) (33/154) and 2x MIC resulted in over 95% reduction in bacterial populations within 30 minutes. Notably, the bacteria did not develop resistance to increased temperatures. M-PEX12 effectively disrupted biofilm formation at various concentrations. Field emission SEM revealed significant ultrastructural deformities in <i>A. baumannii</i> cell walls. Treatment with M-PEX12 increased production of intracellular ROS and decreased cell viability in a concentration-dependent manner. Cytotoxicity assays showed no significant effect on <i>HEK293</i> cell viability. Additionally, expression levels of <i>omp33</i>, <i>csuE</i>, <i>bfmR</i>, and <i>ompA</i> were significantly reduced. The antimicrobial efficacy of M-PEX12 was confirmed in vivo.</p><p><strong>Conclusions: </strong>M-PEX12 exhibited significant antimicrobial activity and low toxicity in a mouse model, suggesting its potential as a treatment for drug-resistant bacterial infections.</p>","PeriodicalId":14595,"journal":{"name":"Iranian Journal of Pharmaceutical Research","volume":"24 1","pages":"e154484"},"PeriodicalIF":1.8000,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12297017/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Iranian Journal of Pharmaceutical Research","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.5812/ijpr-154484","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2025/1/1 0:00:00","PubModel":"eCollection","JCR":"Q3","JCRName":"PHARMACOLOGY & PHARMACY","Score":null,"Total":0}
引用次数: 0
Abstract
Background: Acinetobacter baumannii-induced nosocomial pneumonia and its associated biofilm infections pose significant clinical challenges due to high rates of antibiotic resistance. Traditional antibiotic treatments encounter numerous obstacles, making antimicrobial peptides (AMPs) a promising alternative for controlling such pathogens. The emergence of multidrug-resistant strains necessitates the exploration of innovative therapeutic strategies.
Objectives: We recently designed a novel hybrid peptide, M-PEX12, which exhibits antimicrobial activity and low toxicity in vitro. To confirm its therapeutic potential, we evaluated it in both in vitro and in vivo settings.
Methods: M-PEX12 was evaluated using time-kill kinetics, thermal stability, reactive oxygen species (ROS) generation, biofilm inhibition assays, scanning electron microscopy (SEM), cytotoxicity tests, and virulence gene expression analysis. Its in vivo activity against A. baumannii was also assessed in an animal model.
Results: The time-kill kinetics assay indicated that exposure to M-PEX12 at 1x minimum inhibitory concentration (MIC) (33/154) and 2x MIC resulted in over 95% reduction in bacterial populations within 30 minutes. Notably, the bacteria did not develop resistance to increased temperatures. M-PEX12 effectively disrupted biofilm formation at various concentrations. Field emission SEM revealed significant ultrastructural deformities in A. baumannii cell walls. Treatment with M-PEX12 increased production of intracellular ROS and decreased cell viability in a concentration-dependent manner. Cytotoxicity assays showed no significant effect on HEK293 cell viability. Additionally, expression levels of omp33, csuE, bfmR, and ompA were significantly reduced. The antimicrobial efficacy of M-PEX12 was confirmed in vivo.
Conclusions: M-PEX12 exhibited significant antimicrobial activity and low toxicity in a mouse model, suggesting its potential as a treatment for drug-resistant bacterial infections.
期刊介绍：
The Iranian Journal of Pharmaceutical Research (IJPR) is a peer-reviewed multi-disciplinary pharmaceutical publication, scheduled to appear quarterly and serve as a means for scientific information exchange in the international pharmaceutical forum. Specific scientific topics of interest to the journal include, but are not limited to: pharmaceutics, industrial pharmacy, pharmacognosy, toxicology, medicinal chemistry, novel analytical methods for drug characterization, computational and modeling approaches to drug design, bio-medical experience, clinical investigation, rational drug prescribing, pharmacoeconomics, biotechnology, nanotechnology, biopharmaceutics and physical pharmacy.
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