Faezeh Najafzadeh; Asghar Tanomand; Azam Hadadi; Jafar Majidi
Abstract
Background: Pseudomonas aeruginosa is an important opportunistic pathogen, especially in patients with compromised host defense. Objective: To prepare the conjugate of detoxified lipopolysaccharide (D-LPS) and exotoxin A toxoid (T-ETA) from P. aeruginosa in gold nanoparticles (Au NPs) in a mice model. ...
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Background: Pseudomonas aeruginosa is an important opportunistic pathogen, especially in patients with compromised host defense. Objective: To prepare the conjugate of detoxified lipopolysaccharide (D-LPS) and exotoxin A toxoid (T-ETA) from P. aeruginosa in gold nanoparticles (Au NPs) in a mice model. Methods: LPS and ETA were purified from P. aeruginosa PAO1. D-LPS was conjugated with T-ETA via the amidation method. Au NPs were bound to D-LPS-T-ETA conjugate via electrostatic interaction. Mice were immunized with D-LPS, D-LPS-Au NPs, T-ETA, T-ETA-Au NPs, D-LPS-T-ETA, D-LPS-T-ETA-Au NPs, D-LPS-Au NPs+T-ETA-Au NPs, Au NPs, and phosphate-buffered saline (PBS), and specific IgG titers were determined by the ELISA and the whole-cell ELISA methods. Mice in the vaccinated and control groups were exposed to a 2×LD50 of P. aeruginosa and mortality rates were recorded for one week. Results: The results showed that vaccination by D-LPS, D-LPS-Au NPs, T-ETA, T-ETA-Au NPs, D-LPS-T-ETA, D-LPS-T-ETA-Au NPs and D-LPS-Au NPs+T-ETA-Au NPs induced specific IgG. Mice received the D-LPS-T-ETA-Au NPs conjugate showed significant protection against bacterial challenge. Conclusion: These data indicate that D-LPS-T-ETA-Au NPs conjugate has a significant immunogenicity potential to be applied as a new vaccine against Pseudomonas infections.
Mohammad Hadi Fakoor; Parviz Owlia; Seyed Latif Mousavi gargari; Azar Sabokbar
Abstract
Background: Pseudomonas aeruginosa is considered as the most severe cause of infections in burn patients and pneumonia infections. Objective: To study the protective effects of recombinant protein vaccine harboring the PcrV of P. aeruginosa in the mouse model of burn and respiratory infections. Methods: ...
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Background: Pseudomonas aeruginosa is considered as the most severe cause of infections in burn patients and pneumonia infections. Objective: To study the protective effects of recombinant protein vaccine harboring the PcrV of P. aeruginosa in the mouse model of burn and respiratory infections. Methods: Recombinant protein vaccine harboring the PcrV was expressed in the E. coli BL-21 strain. Mice were immunized with the purified recombinant protein, and the antibody titer was measured in the sera obtained from the immunized mice. Immunized and control mice werechallenged by active and passive immunization. The microbial counts in the lung, skin, liver, spleen, and kidney were compared with the control mice. Results: Bioinformatics analysis indicated that the PcrV protein was conserved in 1552 clinical and environmental isolates. Also, the isoelectric point (pI), molecular weight, and Grand Average of Hydropathy (GRAVY) score were analyzed. Mice were injected with recombinant protein, and serum from immunized mice reacted strongly with recombinant antigen at a dilution of 1:64000. The survival rate of mice infected with 5xLD50 of the P. aeruginosa increased significantly up to 75% in the standard strains (PAO1 and PAK), and the number of bacteria, especially in the internal organs (kidney, spleen, and liver) significantly reduced compared to the mice immunized with placebo. Conclusions: Our results demonstrated that the PcrV protein could be an effective candidate vaccine for the generation of antibody response against P. aeruginosa infection.
Leila Safari Zanjani; Reza Shapoury; Mehrouz Dezfulian; Mehdi Mahdavi; Mehdi Shafieeardestani
Abstract
Background: Pseudomonas aeruginosa has an important role in nosocomial infections. Objective: To evaluate biological activity of the detoxified LPS (D-LPS) entrapped into Poly lactic-co-glycolic acid (PLGA) nanoparticles. Materials: LPS was extracted and detoxified from the P. aeruginosa strain PAO1. ...
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Background: Pseudomonas aeruginosa has an important role in nosocomial infections. Objective: To evaluate biological activity of the detoxified LPS (D-LPS) entrapped into Poly lactic-co-glycolic acid (PLGA) nanoparticles. Materials: LPS was extracted and detoxified from the P. aeruginosa strain PAO1. The D-LPS, conjugated to the PLGA nanoparticles with 1-ethyl-3-dimethyl aminopropyl carbodiimide (EDAC) and N-hydroxy-succinimide (NHS). The connection was evaluated by FTIR (Fourier transform infrared), Zetasizer, and Atomic Force Microscope (AFM). The BALB/c mice injected intramuscularly with the D-LPS-PLGA with two-week intervals and then challenged two weeks after the last immunization. The bioactivity of the induced specific antisera and cytokines responses against D-LPS-PLGA antigen was assessed by ELISA. Results: D-LPS-PLGA conjugation was confirmed by FTIR, Zetasizer, and AFM. The ELISA results showed that D-LPS was successful in the stimulation of the humoral immune response. The immune responses raised against the D-LPS-PLGA, significantly decreased bacterial titer in the spleen of the immunized mice after challenge with PAO1 strain in comparison with the control groups. Conclusion: The conjugation of the bacterial LPS to the PLGA nanoparticle increased their functional activity by decrease in bacterial dissemination and increase the killing of opsonized bacteria.
