Biosynthesis of Silver Nanoparticles from Oropharyngeal Candida glabrata Isolates and Their Antimicrobial Activity against Clinical Strains of Bacteria and Fungi

Mohammad Jalal; Mohammad Azam Ansari; Mohammad A Alzohairy; Syed Ghazanfar Ali; Haris M Khan; Ahmad Almatroudi; Kashif Raees

doi:10.3390/nano8080586

Biosynthesis of Silver Nanoparticles from Oropharyngeal Candida glabrata Isolates and Their Antimicrobial Activity against Clinical Strains of Bacteria and Fungi

Nanomaterials (Basel). 2018 Aug 1;8(8):586. doi: 10.3390/nano8080586.

Authors

Mohammad Jalal¹, Mohammad Azam Ansari², Mohammad A Alzohairy³, Syed Ghazanfar Ali⁴, Haris M Khan⁵, Ahmad Almatroudi⁶, Kashif Raees⁷

Affiliations

¹ Department of Microbiology, Jawaharlal Nehru Medical College and Hospital, Aligarh Muslim University, Aligarh 202002, India. jalalmicro@gmail.com.
² Department of Epidemic Disease Research, Institutes of Research and Medical Consultations (IRMC), Imam Abdulrahman Bin Faisal University, 31441 Dammam, Saudi Arabia. maansari@iau.edu.sa.
³ Department of Medical Laboratories, College of applied Medical sciences, Qassim University, Qassim 51431, Saudi Arabia. dr.alzohairy@gmail.com.
⁴ Department of Microbiology, Jawaharlal Nehru Medical College and Hospital, Aligarh Muslim University, Aligarh 202002, India. syedmicro72@gmail.com.
⁵ Department of Microbiology, Jawaharlal Nehru Medical College and Hospital, Aligarh Muslim University, Aligarh 202002, India. harismk2003@hotmail.com.
⁶ Department of Medical Laboratories, College of applied Medical sciences, Qassim University, Qassim 51431, Saudi Arabia. aamtrody@qu.edu.sa.
⁷ Department of Applied Chemistry, Aligarh Muslim University, Aligarh 202002, India. raeeskashif@gmail.com.

Abstract

The objective of the present study was one step extracellular biosynthesis of silver nanoparticles (AgNPs) using supernatant of Candida glabrata isolated from oropharyngeal mucosa of human immunodeficiency virus (HIV) patients and evaluation of their antibacterial and antifungal potential against human pathogenic bacteria and fungi. The mycosynthesized AgNPs were characterized by color visualization, ultraviolet-visible (UV) spectroscopy, fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM). The FTIR spectra revealed the binding and stabilization of nanoparticles with protein. The TEM analysis showed that nanoparticles were well dispersed and predominantly spherical in shape within the size range of 2⁻15 nm. The antibacterial and antifungal potential of AgNPs were characterized by determining minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC)/ minimum fungicidal concentration (MFC), and well diffusion methods. The MBC and MFC were found in the range of 62.5⁻250 μg/mL and 125⁻500 μg/mL, which revealed that bacterial strains were more susceptible to AgNPs than fungal strains. These differences in bactericidal and fungicidal concentrations of the AgNPs were due to the differences in the cell structure and organization of bacteria and yeast cells. The interaction of AgNPs with C. albicans analyzed by TEM showed the penetration of nanoparticles inside the Candida cells, which led the formation of "pits" and "pores" that result from the rupturing of the cell wall and membrane. Further, TEM analysis showed that Candida cells treated with AgNPs were highly deformed and the cells had shrunken to a greater extent because of their interaction with the fungal cell wall and membrane, which disrupted the structure of the cell membrane and inhibited the normal budding process due to the destruction and loss of membrane integrity and formation of pores that may led to the cell death.

Keywords: Candida glabrata; FTIR; MBC; MFC; MIC; TEM; extracellular; membrane integrity; mycosynthesis.