TMPyP-mediated photoinactivation of Pseudomonas aeruginosa improved in the presence of a cationic polymer.

Photochem Photobiol

Departamento de Ciencias Farmacéuticas, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba y UNITEFA-CONICET, Edificio Ciencias II, Medina Allende y Haya de la Torre, Ciudad Universitaria, Córdoba, Argentina.

Published: May 2024

Pseudomonas aeruginosa is one of the most refractory organisms to antibiotic treatment and appears to be one of the least susceptible to photodynamic treatment. TMPyP is effective in the photoinactivation of P. aeruginosa, and the co-administration with the cationic polymer Eudragit®-E100 (Eu) potentiates this effect against isolates both sensitive and resistant to antibiotics. The fluorescent population (>98%) observed by flow cytometry after exposure to Eu + TMPyP remained unchanged after successive washings, indicating a stronger interaction/internalization of TMPyP in the bacteria, which could be attributed to the rapid neutralization of surface charges. TMPyP and Eu produced depolarization of the cytoplasmic membrane, which increased when both cationic compounds were combined. Using confocal laser scanning microscopy, heterogeneously distributed fluorescent areas were observed after TMPyP exposure, while homogeneous fluorescence and enhanced intensity were observed with Eu + TMPyP. The polymer caused alterations in the bacterial envelopes that contributed to a deeper and more homogeneous interaction/internalization of TMPyP, leading to a higher probability of damage by cytotoxic ROS and explaining the enhanced result of photodynamic inactivation. Therefore, Eu acts as an adjuvant without being by itself capable of eradicating this pathogen. Moreover, compared with other therapies, this combinatorial strategy with a polymer approved for pharmaceutical applications presents advantages in terms of toxicity risks.

Download full-text PDF

Source
http://dx.doi.org/10.1111/php.13868DOI Listing

Publication Analysis

Top Keywords

pseudomonas aeruginosa
8
cationic polymer
8
interaction/internalization tmpyp
8
tmpyp
5
tmpyp-mediated photoinactivation
4
photoinactivation pseudomonas
4
aeruginosa improved
4
improved presence
4
presence cationic
4
polymer
4

Similar Publications

Multidrug resistance (MDR) infectious wounds are a major concern due to drug resistance, leading to increased patient morbidity. Lichenysin (LCN), a lipopeptide and biosurfactant obtained from certain strains of , has demonstrated an excellent antimicrobial property. The present study focuses on the fabrication and comprehensive evaluation of LCN-incorporated poly(vinyl alcohol) (PVA)/polycaprolactone (PCL)-based nanofiber scaffolds using an electrospinning technique as a potential wound healing biomaterial for the treatment of MDR infectious wounds in diabetic rats.

View Article and Find Full Text PDF

Twists, turns and jumps: T6SS evolution within species.

Trends Microbiol

March 2025

Department of Microbiology, University of Washington, Seattle, WA, USA; Howard Hughes Medical Institute, University of Washington, Seattle, WA, USA; Microbial Interactions and Microbiome Center, University of Washington, Seattle, WA, USA. Electronic address:

The type VI secretion system mediates interbacterial antagonism between Gram-negative bacteria through delivery of toxic effector proteins. A recent comprehensive genomic analysis by Habich et al. reveals interesting features of the evolution of T6SSs and their corresponding effectors in Pseudomonas aeruginosa, raising questions about functional specialization of the system.

View Article and Find Full Text PDF

This study aims to isolate and identify both diseased and healthy fish pathogens of Ctenopharyngodon idella, Labeo rohita and Oreochromis niloticus and assess their antibacterial and biofilm supressing activities against fish pathogens. It explores their potential to inhibit and degrade biofilms, serving as an alternative to antibiotics in aquaculture while enhancing fish health and disease resistance. Furthermore, the research endeavors to assess the biofilm degradation potential of antibiotics and probiotics, both individually and in combination.

View Article and Find Full Text PDF

Characterization of Klebsiella pneumoniae Carbapenemase (KPC)-14, a KPC Variant Conferring Resistance to Ceftazidime-Avibactam in the Extensively Drug-resistant ST463 Pseudomonas aeruginosa Clinical Isolate.

J Glob Antimicrob Resist

March 2025

Department of Laboratory Medicine, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China; State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China. Electronic address:

Objectives: We studied two Klebsiella pneumoniae carbapenemase (KPC)-14 variants from clinical Pseudomonas aeruginosa isolates (C137 and C159) to better understand the genomic diversity, mechanisms, and genes that confer antibiotic resistance and pathogenicity.

Methods: Genomic DNA from C137/159 was subjected to Illumina and Oxford Nanopore sequencing. Horizontal transmission of the plasmid was evaluated using cloning experiments.

View Article and Find Full Text PDF

Background: Critically ill children are at risk for subtherapeutic antibiotic concentrations. The frequency of target attainment and risk factors for subtherapeutic concentrations of cefepime in children have not been extensively studied.

Methods: We performed an observational study in critically ill children receiving a new prescription of standard dosing of cefepime for suspected sepsis (≥2 systemic inflammatory response syndrome criteria within 48 hours of cefepime start).

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!