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Background and Aim: The prevalence of fluoroquinolone resistance among Pseudomonas aeruginosa isolates, particularly in burn wound infections, has been increasing. The primary cause of ciprofloxacin resistance is attributed to genetic alterations in the quinolone resistance determinant region (QRDR). In this study, we evaluated the antimicrobial resistance profile and QRDR gene mutations in both ciprofloxacin-resistant and non-resistant strains of P. aeruginosa derived from burn wound patients. Materials and Methods: A total of 300 samples were collected from patients with burn wound infections in Guilan, Iran. The isolates were identified as P. aeruginosa, and drug susceptibility tests were conducted using the agar disk diffusion method. DNA extraction and polymerase chain reaction (PCR) analysis were performed for the amplification and sequencing of gyrA, gyrB, parC, and parE genes in the QRDR region. Results: Resistance to Tobramycin, Gentamicin, Piperacillin, Ciprofloxacin, Ceftazidime, and Amikacin was observed in 59.32%, 55.08%, 51.69%, 50.84%, 30.50%, and 26.27% of the isolates, respectively. Forty-two (35.59%) isolates were multidrug- resistant (MDR). The sequencing results in the QRDR region showed that the majority of mutations were in the gyrA gene, with 85.71% of these mutations being the substitution of threonine with isoleucine (Thr-83 Ile) in ciprofloxacinresistant strains. Conclusion: The results of this study indicate that mutations in the gyrA (gyrase gene) are a significant mechanism of resistance to fluoroquinolones. Identifying these mutations can aid in the detection of fluoroquinolone-resistant isolates and simplify treatment challenges by selecting the appropriate antibiotic. [ABSTRACT FROM AUTHOR]

Introduction: Viola plant has been used traditionally to treat neurological disorders. We aimed at determining whether pretreatment with Viola spathulata extract can alleviate the severity of ischemic-reperfusion damages and exert its protective effects through the regulation of a sodium/calcium exchanger (NCX3) gene expression in a rat brain. Methods: Male Wistar rats were divided into two main groups: one main group for evaluating Neurologic Deficit Score (NDS) and Infarct Volume (IV) and the other group for the evaluation of NCX3 gene expression in the brain tissue. The latter group was subdivided into the intact, control (vehicle), sham, V5, and V10. The vehicle (control) subgroup received Dimethyl Sulfoxide (DMSO), and V5 and V10 subgroups received V. spathulata extract at the doses of 5 and 10 mg/kg (IP), respectively, for 7 days. After pretreatment, we carried out Middle Cerebral Artery Occlusion (MCAO) for 60 min. Results: In the V5 and V10 subgroups, NDS and IV significantly decreased. MCAO upregulated NCX3 gene expression in the core, penumbra, and subcortical regions compared with the intact subgroup. The V5 subgroup significantly downregulated the NCX3 gene expression level in the core compared with the control subgroup. The V10 subgroup showed downregulation of the NCX3 gene expression level in the core, penumbra, and subcortex compared with the control subgroup. Conclusion: V. spathulata extract may have a neuroprotective role against MCAO-induced ischemic brain damage, possibly by preventing the alteration of NCX3 gene expression level. [ABSTRACT FROM AUTHOR]

miRNAs as one of the potential therapeutic agents have been recently considered for cancer treatment. AS1411 (aptNCL) is a DNA aptamer specifically binding to nucleolin protein on the cancer cell surface with antiproliferative effect. The aim of the study was to develop a conjugate consisting of aptNCL (as targeted delivery of therapeutic agent) and miRNA let-7d (as a tumor suppressor) using two different linking methods and also to evaluate the potential effect of the conjugates on the proliferation of gastric cancer (MKN-45) cell line compared to negative control cell line of human dermal fibroblast (HDF). Conjugation was performed covalently by SM (PEG)2 as a bifunctional crosslinker (conjugate-1) and noncovalently, using 19bp complementary sticky end sequences (conjugate-2). Nucleolin positive MKN-45 and nucleolin negative HDF cells were cultured and treated with the conjugates. Then, the changes in let-7d expression and cell proliferation were determined using Real-time PCR and MTT methods, respectively. In MKN-45 cells, the conjugates caused significant increase in let7-d uptake compared with HDF cells (P = 0.0001). The conjugate-1, likely due to its higher stability compared with the conjugate-2, led to significantly more increase in intracellular let-7d in MKN-45 cells (30 fold versus 15 fold, respectively, P = 0.0001). The conjugates revealed more potent antiproliferative effect against gastric cancer cells compared with aptNCL alone (P = 0.0001). It was found that the aptNCL-let-7d conjugate efficiently carried let-7d into the cancer cells. Also, it appears that in the setting of aptNCL-let-7d conjugate, let-7d and aptNCL moieties could cooperate and synergistically exhibit the antiproliferative effect on cancer cells. [ABSTRACT FROM AUTHOR]

Background: Type 4 pili (T4P) is an important virulence factor of Pseudomonas aeruginosa (P. aeruginosa). T4P pass the outer membrane through a large oligomeric channel made of a single PilQ protein that is most highly conserved at their C-termini. To develop a functional vaccine that can be used in clinical application, the secretin domain of the PilQ (PilQ380-706) was produced as a recombinant protein. Methods: A 981 bp fragment of C-terminal of the pilQ secretin (pilQ1138-2118) from was designed into the prokaryotic expression vector pET28a. The presence of the pilQ1138-2118 gene in the recombinant construct (pET28a/pilQ) was assessed by double digestion and PCR. After transformation, expression of the recombinant PilQ was induced by addition of IPTG. The expressed recombinant protein was purified by a modified method using a HisTrap affinity column and finally confirmed by SDS-PAGE. The functional activities of the produced PilQ380-706 confirmed by Western blot analysis and twitching inhibition assay. Results: The PCR and enzymatic digestion results showed the presence of the pilQ1138-2118 gene in the construct. The protein electrophoresis showed that the molecular weight of the recombinant PilQ380-706 is approximately 37 kDa. The Western blot analysis confirmed the specificity of specific IgG against the PilQ380-706 protein. The PilQ380-706 protein showed high biological activity in all of these standard assays. Conclusion: Since, the PilQ380-706 protein plays an important role in the biogenesis of pili; and thus, the primary establishment of P. aeruginosa; it seems that it can be used as a candidate vaccine or an adjuvant in the future studies. [ABSTRACT FROM AUTHOR]

Objective(s): Infection with Pseudomonas aeruginosa has been a long-standing obstacle for clinical therapy due to the complexity of the genetics and pathogenesis, as well for widespread resistance to antibiotics, thus attaching great importance to explore effective vaccines for prevention and treatment. This paper focuses on the introduction of novel Pseudomonas aeruginosa type IV pili (T4P)-based fusion protein containing the secretin domain of PilQ and tandem PilA-related peptides. Materials and Methods: We surveyed the expression of the PilQ380-705-PilA fusion protein in-frame with pET26b vector in which a rigid linker was used between two polypeptides and flexible linkers were inserted between the three tandem repeats and each pilA domains. The transformants were expressed in Escherichia coli BL21. The reactivity of specific antisera to the fusion protein was assessed by ELISA. The biological activities of this candidate vaccine were evaluated by western blotting, opsonophagocytosis, and twitching inhibition assays. Results: The fusion protein was purified in high yield by osmotic shock method using HisTrap affinity column. The protein was confirmed by immunoblot analysis. The checkerboard titration showed that the optimal dilution of the antibody to react with antigen is 1:128. Results of opsonophagocytosis assay revealed that the antibodies elevated to the fusion protein promoted phagocytosis of the PAO1 and 6266E strains, so that the twitching immobilization test confirmed these results. Conclusion: Due to excellent killing activity mediated by opsonic antibodies and efficient immobilization of the strains, it seems that PilQ380-705-PilA fusion protein could be a reliable candidate vaccine against P. aeruginosa infection. [ABSTRACT FROM AUTHOR]