Impact of Silver Nanoparticles on Immune Responses as Vaccine against Activated Staphylococcus aureus Bacteria

Staphylococcus aureus is a gram positive bacterium with a broad host range and ubiquitous distribution. S. aureus is a nosocomial pathogen of hospitalized patients brought about extensive morbidity and mortality. It's responsible for causing pneumonia, osteomyelitis, cystitis, prostatitis, meningitis, bacteremia, skin, urogenital tract, central nervous system, and the best method of control is vaccination with locally prevalent strains. Recently, the ability of nanoparticles were assessed as an adjuvant for increase immune responses. Then again, the main response to immunization by neutralizing antibodies in numerous disease. Therefore, we utilized to assess AgNPs adjuvanticity with antigen inactivated S. aureus bacterin. To prepare 0.2 ml (at 2mg/kg concentration) of vaccine used olive oil (75?l) and inactivated S. aureus (25 ?l) were added to AgNPs (100?l) size 88nm. The mice were intraperitoneally immunized by the AgNPs alone as positive control, olive oil alone, inactivated S. aureus only and incomplete Freund's adjuvant only, commercially available adjuvant. The vaccine used two time subcutaneous and intraperitoneal route on first and seventh day. One week later the blood was collected from immunized mice. In the immunized mice, the count of both T and B lymphocytes, neutrophils and monocytes in intraperitoneal and subcutaneous groups were demonstrated an increase in total cell number, but other groups slight increasing, whereas the relative eosinophils and basophils numbers stayed constant contrasted with the control group. Also the results shown that increase in phagocytosis of treated mice's blood {25 (21.36% one dose), 29 (22.48% post dose) } and { 32 (22.2% one dose, 40 (23.2% post dose) } for intraperitoneal and subcutaneous respectively in compared with negative control, and the other groups slight elevation of phagocytosis than negative control 4 (18.1%). The quantity of neutralizing antibodies was dictated in serum, the outcomes demonstrated that administered intraperitoneally (i. p. ) and subcutaneously were significant increased (P? 0.05) which were (9.8 ? 0.08 one dose, 12.3 ? 0.23 post dose) and (11.7 ? 0.11 one dose, 16.2 ? 0.11 post dose) mg/ml respectively than those found in the positive control AgNPs (4.1?0.08 mg/ml), negative control (4?0.05 mg/ml), Killed S. aureus alone (5?0.12 mg/ml) and incomplete Freund's adjuvant (6.2 ? 0.17 mg/ml), and significant differences were observed between 1th (one dose) and 7th days (post immunization). It must be noticed that subcutaneously post-immunization had better impact on immune response. Hence conclude the mechanism of AgNPs have significant adjuvant impact is mainly ascribed to produce immune responses against S. aureus microscopic organisms and which is vital in clinical treatment of S. aureus illness by recruitment and activation of leukocytes.