Vaccination with OprB porin, and its epitopes offers protection against A. baumannii infections in mice.

A. baumannii is a deadly antimicrobial resistance pathogen that acquires drug resistance through different mechanisms. Therefore, it is necessary to investigate all its virulence factors and design effective vaccines against it. For this purpose, OprB, an outer membrane porin, was investigated in this study, and its secondary and tertiary structures, physicochemical properties, and B-T epitopes were determined. The vaccine potential of this protein and its linear, non-continuous, and chimeric epitopes were also in-vivo analyzed. Based on the results, two surface epitopes and one non-continuous epitope were identified. Surface contiguous epitopes were produced recombinantly and non-continuous epitope sequences were synthesized and then produced. The chimeric epitope was also produced via the SOE-PCR technique. Active and passive immunization of mice with the whole OprB protein, non-continuous epitope, contiguous epitopes, two epitopes in chimeric form, as well as the mixture of two purified epitopes showed that the survival level and total IgG titer of the mice compared to non-vaccinated mice or mice that were vaccinated with an internal fragment increased significantly. The bacterial load in the immunized mice's lung, liver, kidney, and spleen was much lower than in the control groups, and the TNF-α, IFN-γ, and IL-6 cytokines levels were also lower in these groups and were similar to the naive mice. On the other hand, subunit vaccines showed acceptable safety and due to their minimal cross-activity, their use is much safer.

Antibiotic delivery in the presence of green AgNPs using multifunctional bilayer carrageenan nanofiber/sodium alginate nanohydrogel for rapid control of wound infections.

This study constructed bilayer nano-hydrogels using solvent casting and electrospinning techniques. The first layer consisted of a hydrogel containing sodium alginate and gellan gum, while the second layer was a carrageenan/polyvinyl alcohol nanofibrous membrane. The nanohydrogels were prepared with different doses of doxycycline antibiotic (0.12, 0.06, 0.03 g) and a fixed amount of silver nanoparticles (0.012 g), which were synthesized using the green method including Capparis spinosa leaf extract. The films were tested for their mechanical properties, swelling behavior, XRD, and FTIR, and their morphology was characterized using SEM. The biological properties of the nanohydrogels were also extensively assayed. X-ray diffraction analysis showed peak 111 for silver nanoparticles. Incorporating silver nanoparticles significantly enhanced nanohydrogels' mechanical and antibacterial properties and improved their ability to heal wounds. Nanohydrogels exhibited biodegradability, biocompatibility, anti-inflammatory properties (57.63 %), and high cell viability (>85 %) in laboratory conditions. The study confirmed that wound dressings containing doxycycline with controlled release are highly effective against pathogenic bacteria and prevent the formation of biofilms (92 %). The rats in-vivo study demonstrated that 100 % wound closure was achieved in nanohydrogels containing SA/GG/PVA/CAR/AgNPs/DOX0.12 after 14 days. The films could potentially lead to the development of new treatments against bacterial infections and inflammatory conditions of wounds.

Nano hydrogel with bacterial nanocellulose and bitter almond oil nanoemulsions for enhanced wound healing: In-vivo and in-vitro characterization.

Biocompatibility, good mechanical properties, infection prevention, and anti-inflammatory are the requirements of an ideal wound dressing for the care and treatment of skin wounds. In this study, the nanohydrogels as wound dressing, were fabricated by bacterial nanocellulose (BNC), polyvinyl alcohol (PVA), and gellan gum. Bitter almond oil nanoemulsion (BAO-NE) was made with ultrasonic force and incorporated into the nanohydrogels in concentrations of 2, 4, and 6 %. The mechanical and physicochemical analyses such as tensile strength (TS), elongation at break (EB), swelling, water vapor transmission rate (WVTR), degradation, FTIR-ATR, and SEM, and anti-inflammatory, antibacterial, etc. properties of the nanohydrogels were investigated. Also, the wound healing ability was evaluated by in-vivo analyses. The molecular analyses of the expression of genes related to collagen production and inflammation were performed. Increasing BAO-NE concentration enhanced anti-inflammatory and antibacterial activities against Gram-negative and Gram-positive bacteria (P < 0.05). The in-vivo study presented the healing role of nanohydrogels in rat wounds. Real-time PCR results confirmed the anti-inflammatory and healing effects of the films at molecular levels. All the results testify to the promising properties of the fabricated nanohydrogels as a potential wound dressing.

A novel vaccine candidate against A. baumannii based on a new OmpW family protein (OmpW2); structural characterization, antigenicity and epitope investigation, and in-vivo analysis.

A. baumannii is an MDR pathogen whose SARS-CoV-2 has recently increased its mortality rate in hospitalized patients. So, the virulence factors investigation and design of a vaccine against this bacterium seem to be critical. In this regard, the OmpW2 protein was structurally characterized by this study, and its B-T cell epitopes were mapped by bioinformatic tools. In-vivo analyses were employed to verify the immunogenicity of this protein and its selected epitopes. The results indicated that OmpW2 is a conserved virulent antigen, not toxic for the host, and not similar to the human or mouse proteome. A putative interaction between OmpW2 and a Fe-S-cluster redox enzyme was detected. Based on the results, OmpW2 belongs to the OmpW superfamily and eight beta sheets have been predicted in its tight beta-barrel structure. Several exposed epitopes were detected in the OmpW2 sequence and structure, and a sub-unit potential vaccine was generated based on the epitopes. The ELISA results indicated that after the second booster vaccination of BALB/c mice with the whole OmpW2 protein or its sub-unit fragment, the IgG titer significantly raised (p < 0.05). The mortality rate and the bacterial burden in the lung, liver, kidney, and spleen in both passive and active immunized mice were significantly decreased (p ≤ 0.001). In-vivo experiments confirmed that the OmpW2 whole protein and its sub-unit fragment induce the host immune system and can be applied to design a commercial vaccine or diagnostic kit.

DcaP porin and its epitope-based subunit promise effective vaccines against Acinetobacter baumannii; in-silico and in-vivo approaches.

A. baumannii is a multi-drug resistant pathogen with a relatively high mortality rate. To date, no vaccine has been approved against this bacterium. DcaP is a high abundance porin during infection that its structure has been recently determined, but no information about its immunogenic properties has been reported yet. So, in this study DcaP properties were analyzed and its vaccine potential was evaluated. The results showed this porin is an extremely conserved antigen with no allergenicity and toxicity that bears no resemblance to human proteins. Six potential immunogen areas in the DcaP sequence were detected based on in-silico B and T-cell epitope mapping and other approaches. A multiple-epitope potential vaccine was designed based on the predicted linear epitopes and amplified by overlap extension PCR technique. In-vivo results indicated that active and passive immunization of mice with the DcaP protein or its designed subunit vaccine raises the antibody titers and decreases the mortality rate of the immunized mice infected with A. baumannii. Based on the results, DcaP and its indicated immunogen regions can be considered as a peptide or subunit vaccine. The immunogen regions could also be applied in multivalent subunit vaccine candidates against A. baumannii and other bacteria.

Physicochemical and structural characterization, epitope mapping and vaccine potential investigation of a new protein containing Tetratrico Peptide Repeats of Acinetobacter baumannii: An in-silico and in-vivo approach.

Acinetobacter baumannii is an opportunistic multidrug-resistant pathogen that causes a significant mortality rate. The proteins containing Tetratrico Peptide Repeats (TPRs) are involved in the pathogenicity and virulence of bacteria and have different roles such as transfer of bacterial virulence factors to host cells, binding to the host cells and inhibition of phagolysosomal maturation. So, in this study, physicochemical properties of a new protein containing TPRs in A. baumannii which was named PcTPRs1 by this study were characterized and its 3D structure was predicted by in-silico tools. The protein B and T cell epitopes were mapped and its vaccine potential was in-silico and in-vivo investigated. Domain analysis indicated that the protein contains the Flp pilus assembly protein TadD domain which has three TPRs. The helix is dominant in the protein structure, and this protein is an outer membrane antigen which, is extremely conserved among A. baumannii strains; thus, has good properties to be applied as a recombinant vaccine. The best-predicted and refined model was applied in ligand-binding sites and conformational epitopes prediction. Based on epitope mapping results, several epitopes were characterized which could stimulate both immune systems. BLAST results showed the introduced epitopes are completely conserved among A. baumannii strains. The in-vivo analysis indicates that a 101 amino acid fragment of the protein which contains the best selected epitope, can produce a good protectivity against A. baumannii as well as the whole TPR protein and thus could be investigated as an effective subunit and potential vaccines.

The Effects of Photobiomodulation Therapy on Post-Surgical Pain.

Introduction: One of the major complains after surgery is pain. Recent advances in the prevention and reduction of postoperative pain have provided several modalities. One of them is the use of laser irradiation on the surgical area. Objectives: To evaluate the effects of low level laser therapy (LLLT) on pain and side effects after surgery. Methods: In this research, databases such as: PubMed, Science Direct, Google Scholar, Springer and Cochrane were used and the words of laser therapy, photobiomodulation, therapeutic laser, low level laser therapy, surgery and pain were searched. Articles, including systematic reviews, original articles, case series, and clinical intervention studies related to these words, were studied. The language of all articles was English and consists of papers from 2009 until 2017. Results: A total of 370 papers were studied and 10 articles that met inclusion criteria were selected for this review. Few of these articles were followed up. Surgery included a wide range of surgeries including mastectomy, breast augment post-fracture, episiotomy, tonsillectomy and hernia. The methodological quality score on the PEDro scale was between 5 and 11. 8 trials reported positive effects and 2 trials reported negative effects. In order to study clinical effect size of laser therapy after surgery, only 4 papers met entry criteria and the mean effect sizes were 0.13 to 2.77. Accordingly, the best treatment protocol included a red laser dose of 4 J/cm2 for the post-operative pain of tonsillectomy, which was irradiated through the infra mandibular angle on the tonsils. Conclusion: LLLT may be an appropriate modality for reducing pain after surgery, nevertheless the effect size of this modality is variable. Therefore, further research based on proper protocols for these patients and follow-up of therapeutic course should be designed and implemented.

Contamination levels and spatial distributions of heavy metals and PAHs in surface sediment of Imam Khomeini Port, Persian Gulf, Iran.

Imam Khomeini Port (IKP) is the largest Iranian commercial port. Because of many petrochemical industries and urban areas are located around this port and also having heavy ship traffic, concentrations of PAHs, mercury and other heavy metals were measured as the first time in surface sediment of the jetties. The highest concentrations of PAHs, Hg, Cu, Pb and Fe were recorded at Site 1, located in the vicinity of the petrochemical industrial zone, where ships are repaired. The highest concentration of Zn was found at Site 4, which is the jetty for loading mineral materials. The comparison between measured values in this study and some sediment quality guidelines indicated that the concentrations of mercury and PAHs are much higher than other studies. Also, the ratios of PAHs in the stations showed a mixture of both of pyrolytic and petrogenic sources with a dominance of pyrolytic sources.

The changes in Tps1 activity, trehalose content and expression of TPS1 gene in the psychrotolerant yeast Guehomyces pullulans 17-1 grown at different temperatures.

The psychrotolerant yeast Guehomyces pullulans 17-1 grows the best at 15 °C. When the yeast cells grown at 15 °C for 48 h were transferred to new medium and grown at 10, 15, and 25 °C, respectively, trehalose-6-phosphate synthase (Tps1) activity and trehalose content of the yeast cells grown at 25 °C were higher than those of the yeast cells grown at 10 and 15 °C. However, Tps1 activity and trehalose content of the yeast cells grown at 10 °C were lower than those of the yeast cells grown at 15 °C. This may suggest that trehalose synthesized by G. pullulans 17-1 only can play more important role in its adaption to high temperature than in its adaption to low temperature. After the GPTPS1 gene encoding trehalose-6-phosphate synthase was cloned from the psychrotolerant yeast, it was found that the promoter of the gene contained several stress-response elements such as C4T and AG4, indicating that the gene expression might be regulated by heat shock. It was also found that the transcriptional level of the GPTPS1 gene in the yeast cells grown at 25 °C was higher than that of the GPTPS1 gene in the yeast cells grown at 10 and 15 °C. However, the transcriptional level of the GPTPS1 gene in the yeast cells grown at 10 °C was lower than that of the yeast cells grown at 15 °C. This meant that expression of the GPTPS1 gene was constant with the changes in Tps1 activity and trehalose content of the yeast cells.