Modulatory effect of Canavalia gladiata lectin on quinolone activity against multidrug-resistant and efflux pump-positive Staphylococcus aureus
- 1Federal University of Cariri
- 2Regional University of Cariri
Abstract
Clinically relevant bacteria have increasingly developed resistance to antimicrobial agents, reducing the effectiveness of conventional antibiotic therapies. In this context, antibiotic adjuvants capable of restoring or enhancing the activity of existing drugs represent a potential strategy against multidrug-resistant bacteria. This study evaluated the potential of a lectin isolated from Canavalia gladiata seeds (CGL) as an antibiotic-modulating agent against multidrug-resistant and efflux pump-positive bacterial strains. CGL was purified by affinity chromatography on Sephadex G-50, and its direct antibacterial activity was evaluated by determining the minimum inhibitory concentration (MIC). Its modulatory effects were subsequently assessed in combination with conventional antibiotics and in assays involving strains carrying the NorA and MepA efflux pumps. CGL showed weak intrinsic antibacterial activity against all tested strains, with MIC values ≥1,024 μg/mL. However, when used at a sub-inhibitory concentration, CGL moderately enhanced the activity of norfloxacin against Staphylococcus aureus 10, reducing the MIC from 256 to 170.6 μg/mL, and ciprofloxacin against S. aureus K2068, reducing the MIC from 32 to 13.3 μg/mL. These effects did not restore bacterial susceptibility to clinically established therapeutic breakpoints. In contrast, no significant enhancement was observed for the other antibiotic combinations, and some associations resulted in increased MIC values. Therefore, CGL does not appear to act as a direct antibacterial agent under the conditions evaluated, but may have potential as an antibiotic adjuvant, particularly in combination with quinolones against selected S. aureus strains. Further mechanistic, toxicity, and in vivo studies are required to determine its applicability as an antibiotic-modulating agent.
Related
- Determinants of Antibacterial Activity in Humulus lupulus Hop Extracts: Phytochemical Profiling of Prenylated Acylphloroglucinols and Efficacy Against Methicillin-Resistant Staphylococcus aureus and Multidrug-Resistant Uropathogenic Escherichia coli
- Drug repurposing enhances antibiotic activity in multidrug-resistant staphylococcus aureus through modulation of oxidative stress homeostasis
- SaeRS Gene Expression Following Exposure to Olive Leaf-Mediated Zinc Oxide Nanoparticles in Multidrug-Resistant Staphylococcus aureus.
- High prevalence and multidrug resistance of Methicillin-resistant Staphylococcus aureus at a provincial referral hospital in Zambia: A 5-year retrospective study
- Investigation of Carbapenemase Resistance Genes and Plasmid-Mediated Quinolone Resistance Genes in Ceftolozane/Tazobactam-Resistant Enterobacterales and Pseudomonas aeruginosa Isolates
BibTeX
@article{junior2026modulatory,
title = {{Modulatory effect of Canavalia gladiata lectin on quinolone activity against multidrug-resistant and efflux pump-positive Staphylococcus aureus}},
author = {Dárcio Luiz de Sousa Júnior and Maria do Socorro Costa and Sheila Alves Gonçalves and Cicera Laura Roque Paulo and Isaac Moura Araújo and Ana Cecília Calixto Donelardy and Antonia Railene de Souza Rodrigues and Rafael Barbosa de Moura and Thiago Sampaio de Freitas and Janaína Esmeraldo Rocha and Henrique Douglas Melo Coutinho and Francisco Nascimento Pereira Júnior},
journal = {Frontiers in Pharmacology},
year = {2026},
month = oct,
doi = {10.3389/fphar.2026.1953977},
url = {https://www.frontiersin.org/articles/10.3389/fphar.2026.1953977/full},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Modulatory effect of Canavalia gladiata lectin on quinolone activity against multidrug-resistant and efflux pump-positive Staphylococcus aureus
AU - Dárcio Luiz de Sousa Júnior
AU - Maria do Socorro Costa
AU - Sheila Alves Gonçalves
AU - Cicera Laura Roque Paulo
AU - Isaac Moura Araújo
AU - Ana Cecília Calixto Donelardy
AU - Antonia Railene de Souza Rodrigues
AU - Rafael Barbosa de Moura
AU - Thiago Sampaio de Freitas
AU - Janaína Esmeraldo Rocha
AU - Henrique Douglas Melo Coutinho
AU - Francisco Nascimento Pereira Júnior
PY - 2026
DA - 2026/10/29
JO - Frontiers in Pharmacology
DO - 10.3389/fphar.2026.1953977
UR - https://www.frontiersin.org/articles/10.3389/fphar.2026.1953977/full
AB - Clinically relevant bacteria have increasingly developed resistance to antimicrobial agents, reducing the effectiveness of conventional antibiotic therapies. In this context, antibiotic adjuvants capable of restoring or enhancing the activity of existing drugs represent a potential strategy against multidrug-resistant bacteria. This study evaluated the potential of a lectin isolated from Canavalia gladiata seeds (CGL) as an antibiotic-modulating agent against multidrug-resistant and efflux pump-positive bacterial strains. CGL was purified by affinity chromatography on Sephadex G-50, and its direct antibacterial activity was evaluated by determining the minimum inhibitory concentration (MIC). Its modulatory effects were subsequently assessed in combination with conventional antibiotics and in assays involving strains carrying the NorA and MepA efflux pumps. CGL showed weak intrinsic antibacterial activity against all tested strains, with MIC values ≥1,024 μg/mL. However, when used at a sub-inhibitory concentration, CGL moderately enhanced the activity of norfloxacin against Staphylococcus aureus 10, reducing the MIC from 256 to 170.6 μg/mL, and ciprofloxacin against S. aureus K2068, reducing the MIC from 32 to 13.3 μg/mL. These effects did not restore bacterial susceptibility to clinically established therapeutic breakpoints. In contrast, no significant enhancement was observed for the other antibiotic combinations, and some associations resulted in increased MIC values. Therefore, CGL does not appear to act as a direct antibacterial agent under the conditions evaluated, but may have potential as an antibiotic adjuvant, particularly in combination with quinolones against selected S. aureus strains. Further mechanistic, toxicity, and in vivo studies are required to determine its applicability as an antibiotic-modulating agent.
SN - 1663-9812
ER -