Activity of lipid-loaded lectin against co-infection of Candida albicans and Staphylococcus aureus using the zebrafish model

Aim Nosocomial infection caused by mixed species of methicillin-resistant Staphylococcus aureus (MRSA) and Candida albicans (CA) is difficult to manage with existing antimicrobials, particularly in the presence of mixed-species biofilm. This study evaluates the activity of cationic lipid, specifically functionalized with lectin, against mixed biofilms of MRSA and CA and their effectiveness in vivo using the zebrafish model. Methods and Results The present study demonstrates for the first time the antimicrobial activity of 2-((N-[2-hydroxyethyl]palmitamido)methyl)-1-methylpyridin-1-ium iodide (cN16E) against MRSA and mixed species of MRSA + CA. The cN16E functionalized with Butea monosperma seed lectin (BMSL) showed a lower minimum inhibitory concentration (MIC) as compared with cN16E. BMSL-cN16E (BcN16E) exhibited strong membrane-damaging activity at a lower concentration than cN16E. Crystal violet assay showed that BcN16E inhibits mixed-species biofilm at the concentration of 15.63 mu M, which is four-fold lower than the MIC. Especially, BcN16E was found to be effective in disturbing mature mixed biofilm at 31.25 mu M, which is two-fold lower than the MIC, suggesting true antibiofilm activity without pressurizing the microorganisms. The treatment with BcN16E significantly reduced the exopolysaccharide synthesis (> 78%), cell surface hydrophobicity (> 70 %), hyphae formation, staphyloxanthin biosynthesis (> 41 %), and antioxidant enzyme and hemolysin activity (> 70 %). Notably, BcN16E was efficient in reducing the in vivo colonization of bacterial and fungal burden in the blood and muscle tissues of zebrafish. Conclusion Antimicrobial and antibiofilm efficacy of BcN16E against MRSA, and mixed species of MRSA + CA were demonstrated. Importantly, BcN16E treatment rescued Zebrafish coinfected with mixed species of MRSA + CA. Significance and Impact of the study: The results highlight that antimicrobial loaded on lectin provides an additional advantage to recognize microorganism surface glycans and maximize drug delivery to treat polymicrobial infections caused by MRSA and CA.