Sensitivity of Proteus vulgaris to Zinc Oxide Nanoparticles

Sains Malaysiana 51(5)(2022): 1353-1362 http://doi.org/10.17576/jsm-2022-5105-07

ABSTRACT Zinc oxide nanoparticle (ZnO NP) has become a popular choice in nanomedicine and in the treatment of infections. The present study investigated the sensitivity of Proteus vulgaris to ZnO NPs. The bacteriostatic and bactericidal effects on P. vulgaris were determined by using turbidity and colony count methods. The oxidative stress induced by the treatment of ZnO NPs was evaluated by investigating the level of intracellular reactive oxygen species (ROS) along with lipid peroxidation (LP) analysis. The results showed the highest bacterial growth inhibition of 76.21±1.91 and 87.49±3.29% determined using the turbidity and colony count methods, respectively. The highest oxidative stress effects were observed in P. vulgaris exposed to 100 µg/mL of ZnO NPs for 24 h as shown by 510.90±108.53% increase in ROS production and 328.77±44.36% increase in LP level. The Fourier transform infrared spectroscopy (FTIR) spectrum illustrated the possible involvement of functional groups such as amine, alkane, acid and alkene from the bacterial cell wall in allowing the surface attachment of nanoparticles on the bacterial cells. Hence, the present study clearly demonstrated the sensitivity of P. vulgaris to ZnO NPs.

INTRODUCTION Metal nanoparticles (MNPs) are one of the most studied nanomaterials in biomedical research as the transporter of therapeutic substances (Kumar & Anthony 2016). Zinc oxide nanoparticle (ZnO NP) is a popular choice for therapeutic applications due to its effective antibacterial and anticancer properties (Djearamane et al. 2019; Elshama et al. 2018). Although there are many other MNPs like titanium dioxide (TiO2 ), silver (Ag) and copper (II) oxide (CuO) currently available in the industry with reported antibacterial, antifungal and anticancer properties, ZnO NP is preferred due to its low toxicity level, higher sensitivity and cheaper cost (Mishra et al. 2017). ZnO NPs are reported to be the least toxic to human cells as these particles do not cause any disruption to human deoxyribonucleic acid (DNA) but are harmful to bacterial cells (Sirelkhatim et al. 2015). The non-toxic property of ZnO NP is one of the key reasons for its extensive usage in biomedicine as well as in commercial products like skin care products. ZnO NP is also claimed to be compatible to human skin, hence it is accepted to be used in skin care products, clothes and materials that can come in touch with human skin (Mirzaei & Darroudi 2017). In biomedicine, ZnO NP is widely used in treating cancer and inflammation, and is also a suitable agent for healing wounds (Mishra et al. 2017). In the present study, the sensitivity of Gramnegative bacterium P. vulgaris to ZnO NPs was studied through investigating the growth inhibition and oxidative stress effects of ZnO NP on P. vulgaris.

Sains Malaysiana 51(5)(2022): 1353-1362 http://doi.org/10.17576/jsm-2022-5105-07