Antibacterial Efficacy of AgNPs synthesized from Aloe vera extract and Staphylococcus aureus Culture Supernatant

Abstract

Biological synthesis of silver nanoparticles (AgNPs) is an emerging method that avoids the need for costly equipment and hazardous chemicals. Therefore, in this study, Aloe vera (AV) extract and culture supernatant of Staphylococcus aureus (CS-S. aureus) were used to reduce and stabilise silver nanoparticles. The NPs were characterized using UV–vis spectrophotometry at 445 nm for AV-AgNP and 444.5 nm for CS-S.aureus AgNP, and the presence of silver was confirmed by energy dispersive X-ray (EDX). Furthermore, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed that the AV-CS of S. aureus-AgNPs had irregular and spherical shapes, with average sizes of 18.5 nm for AvAgNPs and 7.03 nm for CS-S. aureus-AgNPs. Additionally, the minimum inhibitory concentration (MIC) of both AgNPs showed a similar reaction. K. pneumoniae, P. aeruginosa, and S. epidermidis were more sensitive to the AgNPs compared to methicillin-resistant Staphylococcus aureus (MRSA). In conclusion, our study used a green method to synthesise silver nanoparticles using AV extract and CS of S. aureus. The NPs showed a remarkable antibacterial effect, especially CS-S. aureus-AgNP, which could have application as a treatment against both Gram-positive and Gram-negative bacteria.

Keywords

• Staphylococcus aureus
• Aloe vera extract
• Cell-free supernatant
• AgNPs
• AvNPs
• Antibacterial activity