Maryam Shirdel
1, Hossein Tajik
1,2, Mehran Moradi
1*1 Department of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, Urmia University, 1177, Urmia, West Azarbaijan, Iran.
2 Department of Medicinal and Industrial Plant, Institute of Biotechnology, Urmia University, 1177 Urmia, Iran.
Abstract
Purpose: The aim of this study was to investigate antimicrobial
and biofilm removal potential of Zataria multiflora essential oil (ZEO)
and silver nanoparticle (SNP) alone and in combination on Staphylococcus
aureus and Salmonella Typhimurium and evaluate the mechanism of
action.
Methods: The minimum inhibitory concentration (MIC), and
optimal inhibitory combination (OIC) of ZEO and SNP were determined according
to fractional inhibitory concentration (FIC) method. Biofilm removal potential
and leakage pattern of 260-nm absorbing material from the bacterial cell during exposure to the compounds
were also investigated.
Results: MICs of SNP for both bacteria were the same as 25 μg/
mL. The MICs and
MBCs values of ZEO were 2500 and 1250 μg/mL, respectively. The most
effective OIC value for SNP and ZEO against Salm. Typhimurium and Staph. aureus were 12.5, 625 and 0.78, 1250 μg/ mL,
respectively. ZEO and SNP at MIC and OIC concentrations represented a strong
removal ability (>70%)
on biofilm. Moreover, ZEO at MIC and OIC concentrations did a 6-log reduction
of primary inoculated bacteria during 15 min contact time. The effect of ZEO on
the loss of 260-nm material from the cell
was faster than SNP during 15 and 60 min.
Conclusion: Combination of ZEO and SNP
had significant sanitizing activity on examined bacteria which may be suitable
for disinfecting the surfaces.