Antimicrobial evaluation of quaternary ammonium polyethyleneimine nanoparticles against clinical isolates of pathogenic bacteria

Agustín Ortega, Shady Farah, Pedro Tranque, Ana V. Ocaña, Syong H. Nam-Cha, Nurit Beyth, Carmen Gómez-Roldán, Ramón Pérez-Tanoira, Abraham J. Domb, Francisco C. Pérez-Martínez, Juan Pérez-Martínez

Research output: Contribution to journalArticlepeer-review

23 Scopus citations


Peritonitis is a disease caused by bacterial strains that have become increasingly resistant to many antibiotics. The development of alternative therapeutic compounds is the focus of extensive research, so novel nanoparticles (NPs) with activity against antibiotic-resistant bacteria should be developed. In this study, the antibacterial activity of quaternary ammonium polyethyleneimine (QA-PEI) NPs was evaluated against Streptococcus viridans, Stenotrophomonas maltophilia and Escherichia coli. To appraise the antibacterial activity, minimal inhibitory concentration (MIC), minimal bactericidal concentration and bactericidal assays were utilised with different concentrations (1.56-100 μg/ml) of QA-PEI NPs. Moreover, 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) and annexin V/propidium iodide toxicity assays were performed in cell cultures. MICs for S. maltophilia and E. Coli isolates were 12.5 and 25 μg/ml, respectively, whereas the MIC for S. viridans was 100 μg/ml. Furthermore, the growth curve assays revealed that these QA-PEI NPs at a concentration of 12.5 μg/ml significantly inhibited bacterial growth for the bacterial isolates studied. On the other hand, QA-PEI NPs lacked significant toxicity for cells when used at concentrations up to 50 ìg/ml for 48 h. The present findings reveal the potential therapeutic value of this QA-PEI NPs as alternative antibacterial agents for peritonitis, especially against Gram-negative bacteria.

Original languageEnglish
Pages (from-to)342-348
Number of pages7
JournalIET Nanobiotechnology
Issue number6
StatePublished - 1 Dec 2015
Externally publishedYes

Bibliographical note

Publisher Copyright:
© 2015 The Institution of Engineering and Technology.


Dive into the research topics of 'Antimicrobial evaluation of quaternary ammonium polyethyleneimine nanoparticles against clinical isolates of pathogenic bacteria'. Together they form a unique fingerprint.

Cite this