Effect of Metallic Nanoparticles on Nosocomial Bacteria

Metallic Nanoparticles: Evaluation of Their Antibacterial, Antibiofilm and Synergistic Effect in Combination With Antibiotics on Nosocomial Bacteria

This research aims to study the properties of metallic nanoparticles"MNPs" (silver nanoparticles "AgNps" and copper nanoparticles "CuNps") on the 2 most common nosocomial bacteria which are highly resistant to antibiotics including Staphylococcus aureus and Pseudomonas aeruginosa, to evaluate the growth inhibiting properties of MNPs on all bacterial isolates, to evaluate the biofilm inhibitory effect on biofilm forming bacterial isolates and the synergistic effect of these MNPs in combination with antibiotics on the antibiotic resistant isolates.

There is a rapid increase in the number of health care associated infections (HAIs) due to multi-drug resistant (MDR) bacterial strains which have a worse prognosis being associated with significant morbidity and mortality, particularly in critically ill patients. The main problem with MDR strains is their limited treatment options, posing a major challenge for health care providers.The increasing utilization and immense studies of nanoparticles have brought new perspectives towards new antimicrobial material that could hinder the MDR bacteria pandemic currently faced. Particularly, metallic nanoparticles exhibit strong biocidal properties on different bacterial species, including MDR bacteria. Another important aspect of the antimicrobial properties of metallic nanoparticles is their potential to eradicate or inhibit microbial biofilm formation, which is an important virulence factor in many localized chronic infections.

Staphylococcus aureus is an example of gram positive bacteria which is a strong biofilm producer and highly resistant to antibiotics. Staphylococcus aureus will be exposed to silver nanoparticles and copper nanoparticles separately to study their antibacterial and biofilm inhibiting properties and their synergistic effect in combination with antibiotics.

Pseudomonas aeruginosa is an example of gram negative bacteria which is a strong biofilm producer and highly resistant to antibiotics. Pseudomonas aeruginosa will be exposed to silver nanoparticles and copper nanoparticles separately to study their antibacterial and biofilm inhibiting properties and their synergistic effect in combination with antibiotics.

Measurement of the inhibition zone diameter by (mm) around wells containing silver nanoparticles on nutrient agar containing 105 cfu/ml (colony forming unit/ml) Staphylococcus aureus

Measurement of the inhibition zone diameter by (mm) around wells containing silver nanoparticles on nutrient agar containing 105 cfu/ml Pseudomonas

Measurement of the inhibition zone diameter by (mm) around wells containing copper nanoparticles on nutrient agar containing 105 cfu/ml Staphylococcus aureus

Measurement of the inhibition zone diameter by (mm) around wells containing copper nanoparticles on nutrient agar containing 105 cfu/ml Pseudomonas

Antibiofilm Activity:12 μg/mL of AgNPs will be added to 107 CFU/mL of Staph aureus. using a microtiter plate reader at 595 nm, biofilm scores: nonbiofilm forming (-), weak (+), moderate (++), and strong (+++)

Antibiofilm Activity:12 μg/mL of CuNPs will be added to 107 CFU/mL of Staph aureus. using a microtiter plate reader at 595 nm, biofilm scores: nonbiofilm forming (-), weak (+), moderate (++), and strong (+++)

Antibiofilm Activity:12 μg/mL of AgNPs will be added to 107 CFU/mL of Pseudomonas. Using a microtiter plate reader at 595 nm, biofilm scores: nonbiofilm forming (-), weak (+), moderate (++), and strong (+++)

Antibiofilm Activity:12 μg/mL of CuNPs will be added to 107 CFU/mL of Pseudomonas. Using a microtiter plate reader at 595 nm, biofilm scores: nonbiofilm forming (-), weak (+), moderate (++), and strong (+++)

Synergism with antibiotics: cefoxitin, Tetracyclin, Ciprofloxacin, Rifampin, Linezolide impregnated with 42.5 μg/mL AgNPs will be placed on nutrient agar containing 105 cfu/ml of Staph aureus. Inhibition zones will be measured (mm).

Synergism with antibiotics: cefoxitin, Tetracyclin, Ciprofloxacin, Rifampin, Linezolide impregnated with 85 μg/mL CuNPs will be placed on nutrient agar containing 105 cfu/ml of Staph aureus. Inhibition zones will be measured (mm).

Synergism with antibiotics:piperacillin-tazobactam, Aztreonam, Imipenem, Colistin, Ciprofloxacin impregnated with 42.5 μg/mL AgNPs will be placed on nutrient agar containing 105 cfu/ml of Pseudomonas. Inhibition zones will be measured (mm).

Synergism with antibiotics:piperacillin-tazobactam, Aztreonam, Imipenem, Colistin ,Gentamicin, Ciprofloxacin impregnated with 85 μg/mL CuNPs will be placed on nutrient agar containing 105 cfu/ml of Pseudomonas. Inhibition zones will be measured (mm).

Inclusion Criteria: Urinary tract infections (UTI) Surgical site infections (SSI) Catheter related blood stream infection (CRBSI) Infected burns Chest infection Exclusion Criteria: Patients less than 18 years. Community acquired infections