---

Background: Brucellosis is one of the most common bacterial zoonotic infections in the world. The incidence of this infection is quite high and is endemic in several countries. According to WHO report, the prevalence of zoonotic and human brucellosis is on the rise in the Mediterranean region, the Middle East, and west Asian countries. The aim of this study was to investigate the usage of silver nanoparticles in treatment of brucellosis. Materials and Methods: In this experimental study, the activity of silver nanoparticles against Brucella meltensis 16M was determined by agar well diffusion method. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of silver nanoparticles were determined by macrodilution method. Also, the antibacterial effect of silver nanoparticles was studied in mouse model. Results: The results showed that silver nanoparticles in low concentrations can kill Brucella melitensis 16M in laboratory conditions. MIC and MBC of silver nanoparticles were 4 ppm and 6 ppm in macrodilution method, respectively. The anti-brucella effect of silver nanoparticles was also observed in mouse model. Conclusion: This study demonstrated that silver nanoparticles can be used against brucellosis.

---

Background: Brucellosis is caused by brucella which is a facultative intracellular pathogen invading both professional and nonprofessional phagosytic cells. Eucalyptus globulus is one of the most widely used medicinal plants in folk medicine throughout the world. The aim of this study was to evaluate the antibacterial effects of Eucalyptus globulus extracts on intramacrophage Brucella melitensis 16M. Materials and Methods: In this experimental study, after preparing aquatic, ethanolic, and acetonic extracts of Eucalyptus globules, the effect of the extracts on intramacrophge survival of B. melitensis 16M obtained from cell culture of Balb/c mice peritoneal macrophages was studied. In order to do this, after lysis of macrophages, through preparation of serial dilutions and culture on Mueller Hinton agar medium, the number of colonies grown was counted. Results: The maximum antimicrobial activity of Eucalyptus globulus extracts on intramacrophage B. melitensis 16 M were in 1:40 dilution (21.62 mg/ml) of the aquatic extract, 1: 640 dilution (1.26 mg/ml) of the ethanolic extract, and 1:320 dilution (2.59 mg/ml) of the acetonic extract after 24h. Conclusion: Aquatic, acetonic, and ethanolic extracts of Eucalyptus globulus possess antimicrobial properties against intramacrophage B. melitensis 16M and ethanolic extract has the most effective antimicrobial activity on intramacrophage Brucella melitensis therefore, these extracts can be useful in treatment of brucellosis.

---

Background: Today, the use of nano-materials is one of the most common methods of making modern medications these materials are very useful in increasing the accessibility of drugs to target. The aim of this study is to obtain immunogenic nano-vaccine against meningitis caused by Haemophilus influenza.

Materials and Methods: In this experimental study, the PRP (polyribosylribitol phosphate) antigen of Haemophilus influenza was conjugated to keyhole limpet hemocyanin (KLH), a powerful immunogen molecule, and a nanoparticle with high adsorption called poly lactic co-glycolic acid (PLGA). The two-part and three-part conjugated antigens were injected into male SW1 race mice. The animals were randomly divided into five groups, which received PRP, PRP+KLH, PRP-KLH, PRP-KLH-PLGA, and PRP-TT intramuscularly together with complete Freund’s adjuvant, respectively. Twenty eight days after injection, blood samples were obtained and increases in serum antibody titer were determined with ELISA technique. For evaluation of the amount of the produced antigen cell entrance into immune cells, immune cells uptake assay and flow cytometry technique were used.

Results: The results showed increases in serum IgG antibody titers of animals immunized with conjugate vaccines. The findings also suggest the higher phagocytosis of conjugated triplex-containing nanoparticle by host immune cells.

Conclusion: The findings of this study indicate that antigen-containing PLGA has considerably higher absorption and immunogenicity and can be more powerful vaccines against Haemophilus meningitis.