Author/Authors :
Alizadeh-Sani, Mahmood Student’s Scientific Research Center - Food Safety and Hygiene Division - Environmental Health Department - School of Public Health - Tehran University Of Medical Sciences, Tehran - Students Research Committee - Department of Food Sciences and Technology - Faculty of Nutrition and Food Sciences - Tabriz University of Medical Sciences , Hamishehkar, Hamed Drug Applied Research Center - Tabriz University of Medical Sciences , Khezerlou, Arezou Students Research Committee - Department of Food Sciences and Technology - Faculty of Nutrition and Food Sciences - Tabriz University of Medical Sciences , Maleki, Mohammad Department of Food Hygiene and Aquaculture - Ferdowsi university of Mashhad , Azizi Lalabadi, Maryam Students Research Committee - Department of Food Sciences and Technology - Faculty of Nutrition and Food Sciences - Tabriz University of Medical Sciences , Bagheri, Vahid Department of Food Science and Technology - Faculty of Agriculture - University of Tabriz , Safaei, Payam Student’s Scientific Research Center - Food Safety and Hygiene Division - Environmental Health Department - School of Public Health - Tehran University Of Medical Sciences, Tehran , Azimi, Taher Department of Microbiology - School of Medicine - Shahid Beheshti University of Medical Sciences, Tehran - Department of Pathobiology - School of Public Health - Tehran University of Medical Sciences , Hashemi, Mohammad Department of Nutrition - Faculty of Medicine - Mashhad University of Medical Sciences , Ehsani, Ali Nutrition Research Center - Department of Food Sciences and Technology - Faculty of Nutrition and Food Sciences - Tabriz University of Medical Sciences
Abstract :
Purpose: The increase of bacterial resistance to common antibacterial agents is one of the
major problems of health care systems and hospital infection control programs. In this study,
antimicrobial activity of titanium dioxide (TiO2) and zinc oxide (ZnO) nanoparticles (NPs) was
investigated against E. coli, Salmonella enteritidis, Listeria monocytogenes, and Staphylococcus
aureus pathogenic bacteria by determining sensitivity coefficient and kinetics of bacterial death.
Methods: Antimicrobial tests were performed with ~106 CFU/mL of each bacterium at baseline.
At first, minimum inhibitory concentration (MIC) was concluded by the dilution method and
then, death kinetic and susceptibility coefficient of NPs suspensions was determined at 0 to 360
min. treatment time.
Results: The results of this study revealed that, the highest susceptibility was observed for L.
monocytogenes (Z=0.025 mL/μg) to TiO2 NPs, whereas the lowest susceptibility was obtained
in the reaction of ZnO NPs with S. enteritidis (Z = 0.0033 mL/μg). The process of bacterial death
in NPs suspension was assumed to follow first-degree kinetic and the survival ratio of bacteria
decreased by the increase in treatment time. An increase in the concentration of NPs was seen
to enhance the bactericidal action.
Conclusion: Results showed that L. monocytogenes had higher sensitivity compared to S.
enteritidis. The results of this study also demonstrated that TiO2 NPs have a strong antimicrobial
effect in comparison with ZnO NPs and it could be employed to aid the control of pathogenic
bacteria.
Keywords :
Pathogenic bacteria , ZnO , TiO2 , Kinetics , Susceptibility coefficient
