Effected of ZnO on Pathogenic Bacteria new presentation.pdf

effoect of zo on pathogenic bacteria presentation with speaker notes

1. Effect of ZnOon Pathogenic Bacteria
•Intruduction
•ZnOnanoparticles have been shown to have a wide range of antibacterial activities
against both Gram-positive and Gram-negative bacteria, including major foodborne
pathogens like Escherichia coli ,Salmonella, Listeria monocytogenes, and Staphylococcus aureus
•The antibacterial activity of the ZnOnanoparticles was inversely proportional to the size
of the nanoparticles in S. aureus. Surprisingly, the antibacterial activity did not require
specific UV activation using artificial lamps, rather activation was achieved under
ambient lighting conditions. Overall, the experimental results suggest that ZnO
nanoparticles could be developed as antibacterial agents against a wide range of
microorganisms to control and prevent the spreading and persistence of bacterial
infections.

2. Effect of ZnOon Pathogenic Bacteria
•What is the action of zinc oxide?
•The proposed mechanism of action of ZnOinvolves theproduction of reactive oxygen
species, which elevates membrane lipid peroxidation that causes membrane leakage
of reducing sugars, DNA, proteins, and reduces cell viability
•The antibacterial effect of ZnOnanoparticles is tested againstStaphylococcus
aureus, (a Gram-positive pathogenic bacterium) from a particle-size, concentration,
and surface-defects point of view. Activation of antibacterial activity was achieved by
standard well diffusion agar and minimum inhibitory concentration procedures. Our
results show that smaller-sized particles are more effective inhibitors of bacterial
activity when used in a certain optimum concentration.

3. Effect of ZnOon Pathogenic Bacteria
•Semiconductor:
•ZnOis ann-typesemiconductor with a large excitonbinding energy (60 meV) and a large
bandgap energy (3.37 eV at room temperature)
•The semiconductor ZnOhas gained substantial interest in the research community in part
because of its large excitonbinding energy (60meV) which could lead to lasing action based
on excitonrecombination even above room temperature. Even though research focusing on
ZnOgoes back many decades, the renewed interest is fueled by availability of high-quality
substrates and reports of ??????-type conduction and ferromagnetic behavior when doped with
transitions metals, both of which remain controversial.

4. Effect of ZnOon Pathogenic Bacteria
•Applications of zinc oxide on pathogenic bacteria:
•Zinc oxide (ZnO) nano/microparticles(NPs/MPs) have been studied as antibiotics
toenhance antimicrobial activity against pathogenic bacteria and viruses with or
without antibiotic resistance. They have unique physicochemical characteristics that can
affect biological and toxicological responses in microorganisms.
•ZnO-NPs exhibit attractive antibacterial properties due toincreased specific surface area
as the reduced particle size leading to enhanced particle surface reactivity. ZnOis a
bio-safe material that possesses photo-oxidizing and photocatalysisimpacts on chemical and
biological species.

5. Effect of ZnOon Pathogenic Bacteria
•Synthesis of ZnO:
•synthesis of ZnOnano-and microparticlesand to study the efectof shapes and sizes on
cytotoxicity towards normal and cancer cells and antibacterial activity toward two kinds of
bacteria. We fabricated ZnOnano-and microparticlesthrough facile chemical and physical
routes. The crystal structure, morphology, textural properties, and photoluminescent
properties were
•characterized by powder X-ray difraction, electron microscopies, nitrogen
adsorption/desorption measurements, and photoluminescence spectroscopy. The obtained
ZnOstructures were highly crystalline and monodispersed with intensive green emission.
ZnONPs and NRs showed the strongest antibacterial activity against Escherichia coli and
Staphylococcus aureus compared to microparticles
•due to their high specifcsurface area

6. Effect of ZnOon Pathogenic Bacteria
•ZnOnanoparticles synthesis by precipitation method:
•Materials . Zinc nitrate, KOH, Absolute ethano, Distilled Water
(0.2M)KOH add
to zinc nitrate
distilled water
white precipitate
was formed
Centrifuged at
5000 rmpfor
20 mint
Washing
with disttled
water and
alcohal
Calcination
at 5000C in
atmosphere
for 3 hr
ZnO
nanoparticles

7. Effect of ZnO on Pathogenic Bacteria
•ZnOnanoparticles synthesis by precipitation method:
•ZnOnanoparticles were synthesized by direct precipitation methodusing zinc nitrate and
KOH as precursors. In this work, the aqueous solution (0.2 M) of zinc nitrate
(Zn(NO3)2.6H2O) and the solution (0.4 M) of KOH were prepared with deionized water,
respectively
•Synthesis of ZnOnanoparticles by co-precipitation method:
•Abstract. Zinc Oxide nanoparticles (ZnONPs) were synthesized as a powder using
the oxalate co-precipitation methodafter calcination at 700 °C. Zine sulfate was
used as a zinc soluble source, and oxalic acid was used as a Catalyst.
The reaction was carried out at room temperature condition.

8. Effect of ZnOon Pathogenic Bacteria
•Used of ZnO:
•Zinc oxide nanomaterials are one of the most extensively used materials in healthcare and
environmental remediation application attributable to their biodegradability and tunable physical
and chemical properties. Firstly we review green methods of the synthesis of ZnONMs as an
alternative to conventional synthesis route as the latter pose environmental risks such as the
requirement of hazardous and expensive precursors as well as production of unwanted end
products.
•Emerging application space for ZnONMs is bio imaging , bio sensing and traceable drug
delivery which take advantage unique and optical properties and florescent behavior.
•The inhibitory action of these NMs against microbes , cancer and inflammation is also covered.

9. Effect of ZnOon Pathogenic Bacteria
•Photocatalytic degradation of ZnO
•Volatile organic compounds (VOCs) are one of the major pollutants present in the petrochemical industrial effluents. These
VOCs have high vapor pressure, which makes it to be dispersed into the atmosphere easily.
•Chlorobenzene is one such Volatile organic compounds, which has an ability to cause adverse impacts on human health by
damaging the central nervous systems. The available treatment methods are unable to effectively treat such VOCs in
environment.
•Photocatalytic degradation is the effective and economical methods, which are being used for the treatment of such
pollutants.
•ZnOis one of the widely accepted photo catalyst, but it has a limitation of wide band-gap energy utilization. This paper
mainly investigates the preparation of metal-doped ZnOnanoparticles using solgeltechnique and its application for the
degradation of chlorobenzene in an aqueous media under different light sources. Among the modified ZnOnanoparticles
prepared (Ag/ZnO, Cd/ZnOand Pb/ZnO), Pb/ZnOwas found to be very effective in the degradation of chlorobenzene.

10. Effect of ZnOon Pathogenic Bacteria
•Effect of gram positive and gram negative bacteria:
•Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria in microbial culture medium were
added to reverse spin bioreactors that contained different concentrations of each ZnOtype to enable dynamic
mixing of the bacteria-ZnOsuspensions.
•A correlation between increasing ZnOparticle concentration and reduction in viable bacteria was not
monotonous. The lowest concentration tested (10 µg/mL) even stimulated bacteria growth
•commercial ZnOparticles at higher concentrations (up to 1000 µg/mL tested), more againstE.
colithanS. aureus.
•The inhibition effects are thus mainly controlled by the interaction dynamics between bacteria
and ZnO, where mixing greatly enhances antibacterial efficacy of all ZnOparticles.
•However, at too low concentrations, ZnOcan stimulate bacteria growth and must be thus used
with caution.

11. Effect of ZnOon Pathogenic Bacteria
•Antibiotic resistance of bacteria:
•The development of antibiotic resistance of bacteria is one of the most pressing problems
in world health care. One of the promising ways to overcome microbial resistance to
antibiotics is the use of metal nanoparticles and their oxides. In particular, numerous studies
have shown the high antibacterial potential of zinc oxide nanoparticles (ZnO-NP) in
relation to gram-positive and gram-negative bacteria.
•Antibacterial activity of nanoparticles based on zinc oxide.

12. Effect of ZnOon Pathogenic Bacteria
•Antibacterial activity of MgO,ZnOand SiO2:
•Antibacterial activity for MgO–ZnOsolid solution was studied by measuring the change in electrical
conductivity with bacterial growth.
•MgO–ZnOsolid solution powders were prepared by heating at 1400°C for 3 h in air.
•we measured the antimicrobial activity of two types of nano-particles ZnO& SiO2
•against different types of (G+ & G-
•) bacteria. We collected 90 samples from four sites of infections (burn,
•wound, urine & sputum) to isolate the following bacteria from hospitalized patients: P. aeruginosa,
•K. pneumoniae& E. coli as gram-negative bacteria (about 15 swabs for each one) and the other
•were S. aureus, S. epidermidis & S. pneumoniaeas gram-positive bacteria

13. Effect of ZnOon Pathogenic Bacteria
•Disease effect the human health:
•Waterborne diseases significantly affect the human health and are responsible for high
mortality rates worldwide.
•Traditional methods of the treatment are now insignificant as maximum bacterial strains
have developed multiple antibiotic resistance toward commonly used antibiotic drugs.
Recently, ZnOnanostructures, due to their biocompatible nature, have attracted the
attention of the scientific community to explore and to understand their cytotoxicity,
•interactions withbiomolecules such as proteins, nucleic acids, fats, cell membranes, tissues,
biological fluids, etc

14. Effect of ZnOon Pathogenic Bacteria
•Effect of ZnOon Biomolecules:
•functionalization of ZnOnanoparticles with biomolecules has been observed to
contribute to their biocompatibility bydecreasing their cytotoxicity against
human cellsbecause of which it has been a widely preferred approach.
•Zinc oxide (ZnO) is extensively used in physical chemistry, biomedical sciences,
catalysts, transducers, microelectronics, textile, cosmetics, and other applications,
because of its small particle size and high specific surface area.
•However, the size, shape, aspect ratio, specific surface area, and surface chemistry
should be maintained at the desired levels for the chemical and biomedical
applications of ZnOnanoparticles

15. Effect of ZnOon Pathogenic Bacteria
•Effect of ZnOon Biomolecules:
•we prepared ZnONPs, coated with the lipid bilayer and characterized their properties.
•Phospholipids, cholesterol, and proteins are the main building blocks of cell membranes. Phospholipids
maintain the dynamic and structural functions of cell membranes
•They have three major components: a phosphate head group (hydrophilic or polar), the glycerol backbone
and two fatty acid tails (long carbon chains, hydrophobic). In water, the hydrophilic heads remain close to the
water, while the tails orient themselves away from that. Then, these phosphate groups cluster together and
form phospholipid bilayers (lipid bilayer)
•Cholesterol is very important for the cell membrane. Cholesterol has a pretty stable structure; it can
randomly insert itself between the phospholipids, and help maintain the fluidity of the cell membranes.
Therefore, the interactions between phospholipids and potential cell-membrane damaging agents should be
studied for understanding the biological effects