Synergistic antimicrobial action of phyco-synthesized silver nanoparticles and nano-fungal chitosan composites against drug resistant bacterial pathogens

Figures & data

Figure 1. FTIR spectra of nanoparticles synthesized from silver (Ag-NPs), fungal chitosan (FC-NPs) and their nanocomposite.

Table 1. Characteristic attributes of nanoparticles synthesized from silver (Ag-NPs), fungal chitosan (FC-NPs) and their nanocomposite.

Nanoparticles	Size range (nm)	Median diameter (nm)	Mean diameter (nm)	Z-potential (mV)
Ag-NPs	13.8‒68.9	41.6	37.2	−11.4
FC-NPs	55.2‒118.9	72.2	68.4	+26.3
Ag/FC nanocomposite	68.3‒142.8	83.8	79.6	+21.9

Figure 2. Transmission micrographs of nanoparticles synthesized from silver (Ag-NPs) and fungal chitosan (FC-NPs).

Table 2. Antimicrobial potentialities of nanoparticles synthesized from silver (Ag-NPs), fungal chitosan (FC-NPs) and their nanocomposite (Ag/FC-NPs) against drug resistant bacterial pathogens.

Examined nanoparticles	Antibacterial activity
	Salmonella Typhimurium		Staphylococcus aureus
	ZOI (mm)*	MIC (µg/mL)	ZOI (mm)	MIC (µg/mL)
Ag-NPs	17.2±1.1 ^a**	6.0	17.6±1.2 ^a**	6.5
FC-NPs	12.3±0.9 ^b**	17.5	11.5±0.8 ^b**	19.0
Ag/FC-NPs	25.9±1.5 ^c**	3.50	23.8±1.4 ^c**	4.0
Ceftriaxone	18.2±1.4 ^a	NT	ND	NT
Gentamycin	27.3±1.8 ^c	NT	30.5±2.2 ^d	NT
Tetracycline	ND	NT	23.9±1.7 ^c	NT

*Inhibition zones present means of triplicate measurements with standard deviation (±SD), including diameter of disc assay (6 mm) that was loaded with 100 µg of nanoparticles.

**Same superscript symbols (in the same row) and letters (in the same column) indicate non-significant difference at p < 0.05.

***ND: No inhibition zone was detected. NT: Not tested.

Figure 3. Scanning micrographs of resistant Salmonella Typhimurium treated with silver/fungal chitosan nanocomposite for 4 h and 8 h, compared with control (non-treated) cells.

Note: The examined Ag/FC-NPs concentration was 5 µg/mL