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Background and Objectives: Staphylococcus simulans secretes an antimicrobial compound called lysostaphin, which has bactericidal properties. It destroys staphylococci through the hydrolysis of peptidoglycan in the cell wall. Therefore, this unique property indicates the high ability of lysostaphin in the treatment of staphylococcal infections and is considered as an anti-staphylococcal agent. Materials and Methods: Escherichia coli BL21 (DE3) competent cells were transformed with pET32a-lysostaphin clone and induced by isopropyl-ß-D-thio-galactoside (IPTG). The recombinant protein was purified by affinity chromatography. Recombinant lysostaphin -A-based ointment was used for external wound healing in animal model. In vivo activity of ointment was evaluated by clinical evidences and cytological microscopic assessment. Results: Our results showed the recombinant protein was produced exactly. The results of checkerboard tests showed MIC, MBC and antibacterial activity test an acute reduction of cell viability during the use of lysostaphin, and SEM results approved the intense wrecking effects of lysostaphin in combination on bacterial cells. Macroscopic findings and microscopic data showed that the recombinant lysostaphin ointment was effective on excisional wound healing. Conclusion: Our findings proved that the recombinant lysostaphin ointment was effective on wound healing due to Staphylococcus aureus infection.
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Objectives: Antimicrobial peptide compounds (AMPs) play important roles in the immune system. They also exhibit significant anti-tumor and antibacterial properties. Most AMPs are cationic and are able to bind bacterial cell membranes through electrostatic affinity. Ib-AMP4 is a plant-derived AMP that exerts rapid bactericidal functions. In the present study, the antibacterial efficiency of the produced recombinant Ib-AMP4 in elimination of Methicillin-resistant Staphylococcus aureus (MRSA) bacterial infection, was investigated under in vitro and in vivo situations. Materials and Methods: The synthesized Escherichia coli codon-optimized gene sequences of the Ib-AMP4 were expressed in E. coli BL21 (DE3) pLysS. The recombinant Ib-AMP4 was purified and refolding conditions were optimized. The antibacterial efficiency of the refolded peptide against MRSA was tested under in vivo and in vitro situations for treatment of skin and systematic infection of MRSA in a mouse model. Results: Antibacterial assays confirmed the antibacterial function of Ib-AMP4 against MRSA. SEM results proved the destructive effects of applying Ib-AMP4 on MRSA biomembrane. Time-kill curve and growth kinetic assay illustrated rapid antibacterial activity of the produced Ib-AMP4. Moreover, Ib-AMP4 showed significant infection treatment ability in a mouse model and all infected mice receiving Ib-AMP4 protein survived and there was no trace of bacteria in their blood samples. Conclusion: The results confirmed the rapid antibacterial potential of the produced recombinant Ib-AMP4 to be used for efficient treatment of MRSA infection.
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PURPOSE: This study investigates the protective properties of Myrtus communis extract against the oxidative effects of extremely low-frequency magnetic fields (ELFMF). Also, this study is aimed to analyze the conformational changes of hemoglobin, oxidative damages to plasma proteins and antioxidant power of plasma following exposure to ELFMF. MATERIALS AND METHODS: Adult male rats were divided into 3 groups: (1) control, (2) ELFMF exposure, and (3) ELFMF exposure after M. communis extract administration. The magnetic field (0.7 mT, 50 Hz) was produced by a Helmholtz coil for one month, 2 hours a day. The M. communis extract was injected intraperitoneally at a dose of 0.5 mg/kg before exposure to ELFMF. The oxidative effects of ELFMF were studied by evaluating the hemoglobin, methemoglobin (metHb) and hemichrome levels, absorption spectrum of hemoglobin (200-700 nm), oxidative damage to plasma proteins by measuring protein carbonyl (PCO) levels and plasma antioxidant power according to the ferric reducing ability of plasma (FRAP). The mean and standard errors of the mean were determined for each group. One-way ANOVA analysis was used to compare the means of groups. The significance level was considered to be p < .05. Moreover, artificial neural network (ANN) analysis was used to identify the predictive parameters for estimating the oxyhemoglobin (oxyHb) concentration. RESULTS: Exposure to ELFMF decreased the FRAP which was in concomitant with a significant increase in plasma PCO, metHb and hemichrome concentrations (p < .001). Oxidative modifications of Hb were shown by reduction in optical density at 340 nm (globin-heme interaction) and 420 nm (heme-heme interaction). Administration of M. communis extract increased FRAP values and decreased plasma POC, metHb, and hemichrome concentrations. Also, a significant increase in Hb absorbance at 340, 420, 542, and 577 nm showed the protective properties of M. communis extract against ELFMF-induced oxidative stress in erythrocytes. ANN analysis showed that optical absorption of hemoglobin at 520, 577, 542, and 630 nm and concentration of metHb and hemichrome were the most important parameters in predicting the oxyHb concentration. CONCLUSIONS: Myrtus communis extract enhances the ability of erythrocytes and plasma to deal with oxidative conditions during exposure to ELFMF. Also, ANN analysis can predict the most important parameters in relation to Hb structure during oxidative stress.