Molecular Modeling and Optimization of Type II E.coli l-Asparginase Activity by in silico Design and in vitro Site-directed Mutagenesis.

INTRODUCTION: L-asparaginase (also known as L-ASNase) is a crucial therapeutic enzyme that is widely used in treatment of ALL (acute lymphoblastic leukemia) as a chemotherapeutic drug. Besides, this enzyme is used in the food industry as a food processing reagent to reduce the content of acrylamide in addition to the clinical industry. The improvement of activity and kinetic parameters of the L-ASNase enzyme may lead to higher efficiency resulting in practical achievement. In order to achieve this goal, we chosen glycine residue in position 88 as a potential mutation with advantageous outcomes. METHOD: In this study, firstly to find the appropriate mutation on glycine 88, various in silico analyses, such as MD simulation and molecular docking, were carried out. Then, the rational design was adopted as the best strategy for molecular modifications of the enzyme to improve its enzymatic properties. RESULT: Our in silico findings show that the four mutations G88Q, G88L, G88K, and G88A may be able to increase L-ASNase's asparaginase activity. The catalytic efficiency of each enzyme (kcat/Km) is the most important feature for comparing the catalytic activity of the mutants with the wild type form. The laboratory experiments showed that the kcat/Km for the G88Q mutant is 36.32% higher than the Escherichia coli K12 ASNase II (wild type), which suggests that L-ASNase activity is improved at lower concentration of L-ASN. Kinetic characterization of the mutants L-ASNase activity confirmed the high turnover rate (kcat) with ASN as substrate relative to the wild type enzyme. CONCLUSION: In silico analyses and laboratory experiments demonstrated that the G88Q mutation rather than other mutation (G88L, G88K, and G88A) could improve the kinetics of L-ASNase.

Host and Pathogen-Directed Therapies against Microbial Infections Using Exosome- and Antimicrobial Peptide-derived Stem Cells with a Special look at Pulmonary Infections and Sepsis.

Microbial diseases are a great threat to global health and cause considerable mortality and extensive economic losses each year. The medications for treating this group of diseases (antibiotics, antiviral, antifungal drugs, etc.) directly attack the pathogenic agents by recognizing the target molecules. However, it is necessary to note that excessive use of any of these drugs can lead to an increase in microbial resistance and infectious diseases. New therapeutic methods have been studied recently using emerging drugs such as mesenchymal stem cell-derived exosomes (MSC-Exos) and antimicrobial peptides (AMPs), which act based on two completely different strategies against pathogens including Host-Directed Therapy (HDT) and Pathogen-Directed Therapy (PDT), respectively. In the PDT approach, AMPs interact directly with pathogens to interrupt their intrusion, survival, and proliferation. These drugs interact directly with the cell membrane or intracellular components of pathogens and cause the death of pathogens or inhibit their replication. The mechanism of action of MSC-Exos in HDT is based on immunomodulation and regulation, promotion of tissue regeneration, and reduced host toxicity. This review studies the potential of mesenchymal stem cell-derived exosomes/ATPs therapeutic properties against microbial infectious diseases especially pulmonary infections and sepsis.

Immune response induced by recombinant pres2/S-protein and a pres2-S-protein fused with a core 18-27 antigen fragment of hepatitis B virus compared to conventional HBV vaccine.

Although comprehensive vaccination is the cornerstone of public health programs to control hepatitis B virus (HBV) infections, 5% of people who receive the existing vaccine do not develop proper immunity against HBV. To overcome this challenge, researchers have tried using various protein fragments encoded by the virus genome to achieve better immunization rates. An important antigenic component of HBsAg called the preS2/S or M protein has also received much attention in this area. The gene sequences of preS2/S and Core18-27 peptide were extracted from the GenBank (NCBI). Final gene synthesis was conducted with pET28. Groups of BALB/c mice were immunized with 10 µg/ml of recombinant proteins and 1 µg/ml CPG7909 adjuvant. Serum levels of IF-γ, TNF-α, IL-2, IL-4, and IL-10 were measured by ELISA assay method on spleen cell cultures on day 45, and IgG1, IgG2a, and total IgG titers obtained from mice serum were quantified on days 14 and 45. Statistical analysis did not show any significant difference between the groups regarding IF-γ level. There were, however, significant differences in terms of IL-2 and IL-4 levels between the groups receiving preS2/S-C18-27 with and without adjuvant and the groups receiving both preS2/S and preS2/S-C18-27 (Plus Recomb-Plus Recomb: the group of mice that received both preS2/S and preS2/S-C18-27 simultaneously). The strongest total antibody production was induced by immunization with both recombinant proteins without CPG adjuvant. The groups that received both preS2/S and preS2/S-C18-27, whether with or without adjuvant, were significantly different from those that received the conventional vaccine considering most abundant interleukins. This difference suggested that higher levels of efficacy can be achieved by the use of multiple virus antigen fragments rather than using a single fragment.

Interaction Between SARS-CoV-2 and Pathogenic Bacteria.

The novel human coronavirus, Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), which results in the coronavirus disease 2019 (COVID-19), has caused a serious threat to global public health. Therefore, many studies are performed on the causes and prevalence of this disease and the possible co-occurrence of the infection with other viral and bacterial pathogens is investigated. Respiratory infections predispose patients to co-infections and these lead to increased disease severity and mortality. Numerous types of antibiotics have been employed for the prevention and treatment of bacterial co-infection and secondary bacterial infections in patients with a SARS-CoV-2 infection. Although antibiotics do not directly affect SARS-CoV-2, viral respiratory infections often result in bacterial pneumonia. It is possible that some patients die from bacterial co-infection rather than virus itself. Therefore, bacterial co-infection and secondary bacterial infection are considered critical risk factors for the severity and mortality rates of COVID-19. In this review, we will summarize the bacterial co-infection and secondary bacterial infection in some featured respiratory viral infections, especially COVID-19.

A comparative study of the arazyme-based fusion proteins with various ligands for more effective targeting cancer therapy: an in-silico analysis.

Background and purpose: Recently, the use of immunotoxins for targeted cancer therapy has been proposed, to find new anticancer drugs with high efficacy on tumor cells with minimal side effects on normal cells. we designed and compared several arazyme (AraA)-based fusion proteins with different ligands to choose the best-targeted therapy for interleukin 13 receptor alpha 2 (IL13Rα2)-overexpressed cancer cells. For this purpose, IL13Rα2 was selected as a receptor and IL13 and IL13.E13K were evaluated as native and mutant ligands, respectively. In addition, Pep-1 and A2b11 were chosen as the peptide ligands for targeted cancer therapy. Experimental approach: Several bioinformatics servers were used for designing constructs and optimization. The structures of the chimeric proteins were predicted and verified by I-TASSER, Q-Mean, ProSA, Ramachandran plot, and Verify3D program. Physicochemical properties, toxicity, and antigenicity were predicted by ProtParam, ToxinPred, and VaxiJen. HawkDock, LigPlot+, and GROMACS software were used for docking and molecular dynamics simulation of the ligand-receptor interaction. Findings/Results: The in silico results showed AraA-A2b11 has higher values of confidence score and Q-mean score was obtained for high-resolution crystal structures. All chimeric proteins were stable, non-toxic, and non-antigenic. AraA-(A(EAAAK)4ALEA(EAAAK)4A)2-IL13 retained its natural structure and based on ligand-receptor docking and molecular dynamic analysis, the binding ability of AraA-(A(EAAAK)4ALEA(EAAAK)4A)2-IL13 to IL13Rα2 was sufficiently strong. Conclusion and implications: Based on the bioinformatics result AraA-(A(EAAAK)4ALEA(EAAAK)4A)2-IL13 was a stable fusion protein with two separate domains and high affinity with the IL13Rα2 receptor. Therefore, AraA-(A(EAAAK)4ALEA(EAAAK)4A)2-IL13 fusion protein could be a new potent candidate for target cancer therapy.

Staphylococcal enterotoxin B as DNA vaccine against breast cancer in a murine model.

Recently, many efforts have been made to treat cancer using recombinant bacterial toxins and this strategy has been used in clinical trials of various cancers. Therapeutic DNA cancer vaccines are now considered as a promising strategy to activate the immune system against cancer. Cancer vaccines could induce specific and long-lasting immune responses against tumors. This study aimed to evaluate the antitumor potency of the SEB DNA vaccine as a new antitumor candidate against breast tumors in vivo. To determine the effect of the SEB construct on inhibiting tumor cell growth in vivo, the synthetic SEB gene, subsequent codon optimization, and embedding the cleavage sites were sub-cloned to an expression vector. Then, SEB construct, SEB, and PBS were injected into the mice. After being vaccinated, 4T1 cancer cells were injected subcutaneously into the right flank of mice. Then, the cytokine levels of IL-4 and IFN-γ were estimated by the ELISA method to evaluate the antitumor activity. The spleen lymphocyte proliferation, tumor size, and survival time were assessed. The concentration of IFN-γ in the SEB-Vac group showed a significant increase compared to other groups. The production of IL-4 in the group that received the DNA vaccine did not change significantly compared to the control group. The lymphocyte proliferation increased significantly in the mice group that received SEB construct than PBS control group (p < 0.001). While there was a meaningful decrease in tumor size (p < 0.001), a significant increase in tumor tissue necrosis (p < 0.01) and also in survival time of the animal model receiving the recombinant construct was observed. The designed SEB gene construct can be a new model vaccine for breast cancer because it effectively induces necrosis and produces specific immune responses. This structure does not hurt normal cells and is a safer treatment than chemotherapy and radiation therapy. Its slow and long-term release gently stimulates the immune system and cellular memory. It could be applied as a new model for inducing apoptosis and antitumor immunity to treat cancer.

The role of serum circulating microbial toxins in severity and cytokine storm of COVID positive patients.

The emergence of Coronavirus disease 2019 (Covid-19) is a global problem nowadays, causing health difficulty with increasing mortality rates, which doesn't have a verified treatment. SARS-CoV-2 infection has various pathological and epidemiological characteristics, one of them is increased amounts of cytokine production, which in order activate an abnormal unrestricted response called "cytokine storm". This event contributes to severe acute respiratory distress syndrome (ARDS), which results in respiratory failure and pneumonia and is the great cause of death associated with Covid-19. Endotoxemia and the release of bacterial lipopolysaccharides (endotoxins) from the lumen into the bloodstream enhance proinflammatory cytokines. SARS-CoV-2 can straightly interplay with endotoxins via its S protein, leading to the extremely elevating release of cytokines and consequently increase the harshness of Covid-19. In this review, we will discuss the possible role of viral-bacterial interaction that occurs through the transfer of bacterial products such as lipopolysaccharide (LPS) from the intestine into the bloodstream, exacerbating the severity of Covid-19 and cytokine storms.

Comparison of Immune Response in Mice Immunized with Recombinant PreS2/S-C18-27 Protein Derived from Hepatitis B Virus with Commercial Vaccine.

Background & Objective: The vaccine available to prevent Hepatitis B virus disease is ineffective in 5% of people due to the use of HBsAg as a weak immunogenic factor. In the present study, PreS2/S fused to C18-27 peptide fragment as an effective antigen and is proposed as a promising vaccine candidate compared with the conventional vaccine prescribed in the vaccination program. Methods: After the synthesis of PreS2/S genes and C18-27 peptide fragment in pET28a, the recombinant protein was confirmed by Western blotting. The efficacy of the PreS2/S-C18-27 protein was compared with the conventional vaccine injected into five groups of rats. Finally, the cytokine level of IF-r, IL-2, IL-4, IL-10, TNF-a, IgG1, and IgG2a were measured using the ELISA method. Results: This study showed no significant difference between the recombinant vaccine group and PBS control group in the IF-r test, but there was a significant difference between groups testing IL-2 and IL-10. In addition, the group receiving the recombinant vaccine with CPG adjuvant at a dilution of 1/10 in the IgG total test on days 14 and 45 after the first injection showed a significant difference in comparison with other groups. Conclusion: This study showed no statistically significant difference between the recombinant protein vaccine group and the conventional vaccine group. The Th1- mediated immune responses obtained from recombinant proteins with and without CPG performed better than conventional vaccines, possibly due to the functional deficiency of the available vaccines.

Evaluation of Triple Fragment Vaccine HSPX (Rv2031c) + PPE44 (Rv2770c) + Mouse IgG1 (Fcγ2a) with Auxiliary Adjuncts IL-22 in Comparison with BCG Vaccine.

Background & Objective: Despite the vaccination with the BCG vaccine, tuberculosis (TB) remains one of the major health problems in the world. The aim of this study was to evaluate our newly designed vaccine using IL-22 as an adjuvant in comparison with the common BCG vaccine. Methods: The gene constructs were cloned into the expression vector of pET28a and then into the recombinant vector of PET28a - HSPX, and PPE44 was transformed into Escherichia coli BL21 (DE3). Finally, the immunogenicity of recombinant proteins with and without BCG and IL-22 in BALB/c mice was investigated. Results: The key cytokines INF-γ and TNF-α were elevated more greatly in BCG immunized group than in PHF immunized group. Immunization with PHF showed a significant increase in IL-4 levels versus the BCG group. Adding IL-22 to the vaccine formulations indicated a tiny increase in IL-4 levels compared to their related vaccine groups.Specific total IgG1 in the experimental groups showed an increase in comparison with control groups, but in the vaccinated groups, no significant differences were observed, and the presence of IL-22 in the vaccine formulations indicated a slight decrease compared with the related mere vaccine groups. Results of specific total IgG2a in the experimental groups revealed that only in the PHF group formulated with IL-22 a significant increase occurs compared with all other experimental groups. Conclusion: It seems that BCG, as the only licensed vaccine for TB infection, could be more potent than a recombinant vaccine in the induction of cellular and humoral immune responses.

Evaluating the Performance of PPE44, HSPX, ESAT-6 and CFP-10 Factors in Tuberculosis Subunit Vaccines.

Mycobacterium tuberculosis (M. tuberculosis) is an intracellular pathogen causing long-term infection in humans that mainly attacks macrophages and can escape from the immune system with the various mechanisms. The only FDA-approved vaccine against M. tuberculosis (MTB) is Mycobacterium bovis bacillus Calmette-Guérin (BCG). The protection of this vaccine typically lasts 10-15 years. Due to the increasing number of people becoming ill with MTB each year worldwide, the need to develop a new effective treatment against the disease has been increased. During the past two decades, the research budget for TB vaccine has quadrupled to over half a billion dollars. Most of these research projects were based on amplifying and stimulating the response of T-cells and developing the subunit vaccines. Additionally, these studies have demonstrated that secretory and immunogenic proteins of MTB play a key role in the pathogenesis of the bacteria. Therefore, these proteins were used to develop the new subunit vaccines. In this review, based on the use of these proteins in the successful new subunit vaccines, the PPE44, HSPX, CFP-10 and ESAT-6 antigens were selected and the role of these antigens in designing and developing new subunit vaccines against TB and for the prevention of TB were investigated.

Evaluation of the Role of Probiotics As a New Strategy to Eliminate Microbial Toxins: a Review.

Probiotics are living microorganisms that have favorable effects on human and animal health. The most usual types of microorganisms recruited as probiotics are lactic acid bacteria (LAB) and bifidobacteria. To date, numerous utilizations of probiotics have been reported. In this paper, it is suggested that probiotic bacteria can be recruited to remove and degrade different types of toxins such as mycotoxins and algal toxins that damage host tissues and the immune system causing local and systemic infections. These microorganisms can remove toxins by disrupting, changing the permeability of the plasma membrane, producing metabolites, inhibiting the protein translation, hindering the binding to GTP binding proteins to GM1 receptors, or by preventing the interaction between toxins and adhesions. Here, we intend to review the mechanisms that probiotic bacteria use to eliminate and degrade microbial toxins.

Prediction of Genes Involved in Lung Cancer with a Systems Biology Approach Based on Comprehensive Gene Information.

Over the past few years, hundreds of genes have been reported in relation to lung cancer. Systems biology studies can help validate this association and find the most valid genes to use in the diagnosis and treatment. We reviewed the candidate genes for lung cancer in 120 published articles from September 1, 1993, to September 1, 2020. We obtained 134 up- and 36 downregulated genes for lung cancer in this article. The genes extracted from the articles were imported to Search Tool for the Retrieval of Interacting genes/proteins (STRING) to construct the protein-protein interaction (PPI) Network and pathway enrichment. GO ontology and Reactome databases were used for describing the genes, average length of survival, and constructing networks. Then, the ClusterONE plugin of Cytoscape software was used to analyze and cluster networks. Hubs and bottleneck nodes were defined based on their degree and betweenness. Common genes between the ClusterONE plugin and network analysis consisted of seven genes (BRCA1-TP53-CASP3-PLK1-VEGFA-MDM2-CCNB1 and PLK1), and two genes (PLK1 and TYMS) were selected as survival factors. Our drug-gene network showed that CASP3, BRCA1, TP53, VEGFA, and MDM2 are common genes that are involved in this network. Also, among the drugs recognized in the drug-gene network, five drugs such as paclitaxel, oxaliplatin, carboplatin, irinotecan, and cisplatin were examined in different studies. It seems that these seven genes, with further studies and confirmatory tests, could be potential markers for lung cancer, especially PLK1 that has a significant effect on the survival of patients. We provide the novel genes into the pathogenesis of lung cancer, and we introduced new potential biomarkers for this malignancy.

A comparative study of laboratory findings in PCR-positive and PCR-negative COVID-19 hospitalized patients.

INTRODUCTION: Given the many misconceptions in terms of both diagnosis and treatment, SARS-CoV-2 continues to infect and victimize. Notwithstanding molecular testing is the gold standard method of in vitro diagnostic, the often long-waiting time, as well as false-negative results are daunting challenges facing us. In this study, we aimed to report the diagnostic value of laboratory findings in COVID-19 patients, with an extensive focus on the differences between PCR-positive and PCR-negative cases. PATIENTS AND METHODS: We did a retrospective single-centre study on a large cohort of 1546 COVID-19 patients in Tehran, Iran. Based on clinical symptoms, chest CTs were performed for all the patients. Also, molecular testing of swab specimens was also performed for 1450 cases. RESULTS: All the data on laboratory results were retrospectively extracted from medical records. Of the 1546 patients, 1040 (67.5%) were male and 506 (32.5%) were female with the mean age of 55.67. On admission, 31.4% of the whole study population displayed lymphopenia and 38.9% showed neutrophilia. Decreased hemoglobin and mild thrombocytopenia were also found in 40% and 18.6% of cases, respectively. Elevated lactate dehydrogenase in nearly 75% of COVID-19 cases was the most common alteration amongst biochemical parameters which together with increased ESR and CRP could serve as diagnostic markers in SARS-CoV-2 infection. Of the 1450 patients with a PCR result, 439 (28.3%) were PCR-negative and 1011 (65.3%) were PCR-positive. Notably, lymphopenia and increased AST were higher in the PCR-positive group than their negative counterparts. Albeit being in the normal range, a significant decrease in the number of monocytes was also evident in the PCR-positive cases. CONCLUSIONS: As far we are aware, this is the first time that we reported a comprehensive exploration of laboratory characteristics of a large cohort of hospitalized COVID-19 patients from Iran, hoping that these data will cast more light on the diagnostic significance of these parameters.

Evaluation of Cytotoxic and Antimicrobial Properties of Iranian Sea Salts: An In Vitro Study.

BACKGROUND: Dental caries is known as a multimicrobial disease. Caries are very prevalent in numerous countries, and the incidence is higher in underdeveloped countries than in developed countries. Dental caries is a major public health problem, and it is the most prevalent health problem across the world, affecting 2.4 billion people. Natural mouthwashes can be beneficial in the prevention of dental caries and oral infections without the side effects of synthetic mouthwashes. AIM: The aim of the present study was to investigate the antibacterial, antifungal, and cytotoxicity properties of sea salt from different areas of Iran. METHODS AND MATERIALS: Sea salts from different areas (Urmia, Qom, and Jarquyeh) of Iran were collected. In order to define the elemental and mineralogical features of different salt samples, X-ray powder diffraction (XRD) was employed. Different concentrations (0.19-50 mg/mL) of sea salt were used in the antimicrobial and antibiofilm tests. The antimicrobial (MIC, MBC, MFC, and DAD tests) and antibiofilm (formation and degradation tests) effects were evaluated against L. acidophilus, S. aureus, E. coli, S. mitis, S. mutans, S. salivarius, and C. albicans. The cytotoxic effect of salts was evaluated on human gingival fibroblasts by the MTT test. RESULTS: The range of MIC values in mg ml-1 was as follows: S. salivarius (50), S. mutans (50), S. mitis (50), L. acidophilus (12.5 to >50), C. albicans (50), E. coli (12.5 to 25), and S. aureus (12.5 to 25), while MBC values were, S. mutans (>50), S. salivarius (>50), S. mitis (>50), L. acidophilus (50 to >50), C. albicans (>50), E. coli (50), and S. aureus (50). MTT results showed that more than 50% of cell viability depends on decreasing the salt concentration (<1.56 mg/ml). CONCLUSION: Sea salts had significant antimicrobial effects on cariogenic bacteria and C. albicans. Therefore, sea salts can be a suitable candidate for mouthwash.

Engineering of Cytolethal Distending Toxin B by Its Reducing Immunogenicity and Maintaining Stability as a New Drug Candidate for Tumor Therapy; an In Silico Study.

The cytolethal distending toxin (CDT), Haemophilus ducreyi, is one of the bacterial toxins that have recently been considered for targeted therapies, especially in cancer therapies. CDT is an A-B2 exotoxin. Its catalytic subunit (CdtB) is capable of inducing DNA double strand breaks, cell cycle arrest and apoptosis in host eukaryotic cells. The sequence alignment indicates that the CdtB is structurally homologyr to phosphatases and deoxyribonucleases I (DNase I). Recently, it has been found that CdtB toxicity is mainly related to its nuclease activity. The immunogenicity of CDT can reduce its effectiveness in targeted therapies. However, the toxin can be very useful if its immunogenicity is significantly reduced. Detecting hotspot ectopic residues by computational servers and then mutating them to eliminate B-cell epitopes is a promising approach to reduce the immunogenicity of foreign protein-based therapeutics. By the mentioned method, in this study, we try to reduce the immunogenicity of the CdtB- protein sequence. This study initially screened residue of the CdtB is B-cell epitopes both linearly and conformationally. By overlapping the B-cell epitopes with the excluded conserve residues, and active and enzymatic sites, four residues were allowed to be mutated. There were two mutein options that show reduced antigenicity probability. Option one was N19F, G74I, and S161F with a VaxiJen score of 0.45 and the immune epitope database (IEDB) score of 1.80, and option two was N19F, G74I, and S161W with a VaxiJen score of 0.45 and IEDB score of 1.88. The 3D structure of the proposed sequences was evaluated and refined. The structural stability of native and mutant proteins was accessed through molecular dynamic simulation. The results showed that the mutations in the mutants caused no considerable changes in their structural stability. However, mutant 1 reveals more thermodynamic stability during the simulation. The applied approaches in this study can be used as rough guidelines for finding hot spot immunogen regions in the therapeutic proteins. Our results provide a new version of CdtB that, due to reduced immunogenicity and increased stability, can be used in toxin-based drugs such as immunotoxins.

The impact of the gut microbiome on toxigenic bacteria.

Millions of symbiotic and pathogenic microorganisms known as microbiota colonize the host body. The microbiome plays an important role in human health and colonizes hundreds of different species of multicellular organisms so that they are introduced as the metaorganisms. Changes in the microbial population of the gut microbiome may cause resistance to pathogenic bacteria-induced infection. Understanding the principles of Host-Microbiota Interactions (HMIs) is important because it clarifies our insight towards the mechanisms of infections established in the host. Interactions between the host and the microbiota help answer the question of how a microorganism can contribute to the health or disease of the host. Microbiota can increase host resistance to colonization of pathogenic species. Studying the HMIs network can in several ways delineate the pathogenic mechanisms of pathogens and thereby help to increase useful and novel therapeutic pathways. For example, the potentially unique microbial effects that target the distinct host or interfere with the endogenous host interactions can be identified. In addition, the way mutations in essential proteins in the host and/or in the microbes can influence the interactions between them may be determined. Furthermore, HMIs help in identifying host cell regulatory modules.

Potent in vitro antitumor activity of B-subunit of Shiga toxin conjugated to the diphtheria toxin against breast cancer.

Immunotoxins are protein-based drugs consist of a target-specific binding domain and a cytotoxic domain to eliminate target cells. Such compounds are potentially therapeutic to combat diseases such as cancer. Generally, the B-subunit of Shiga toxin (STXB) receptor, globotriaosylceramide (Gb3), is expressed in high amounts on a number of human tumors cancer cells. In this study, we evaluated a new antitumor candidate called DT389-STXB chimeric protein, which genetically fused the DT to B-subunit of Shiga-like toxin (STXB). First a chimeric protein, encoding DT389-STXB was synthesized. The optimized chimeric protein expressed in E.coli BL21 (DE3) and confirmed by anti-His Western blot analysis. T47D, SKBR3, 4T1 and MCF7 cell lines were treated separately with purified DT389-STXB recombinant protein and functional activity of DT389-STXB was analyzed by the cell enzyme-linked immunosorbentassay (ELISA), MTT, ICC, Western blot and apoptosis tests. The results indicated that the recombinant DT389-STXB fusion protein with a molecular weight of 53 kDa was successfully expressed in E.coli BL21 (DE3) and the anti-His western-blot was used to confirm the presence of the protein. The DT389-STXB fusion protein attached to T47D, SKBR3 and 4T1 cell lines with the proper affinity and induced dose-dependent cytotoxicity against GB3-expressing cancer cells in vitro. Our results showed that DT389-STXB fusion protein may be a promising candidate for antitumor therapy agent against breast cancer; however, further studies are required to explore its efficacy in vivo for therapeutic applications.

HIV-Tuberculous Meningitis Co-Infection: A Systematic Review and Meta-Analysis.

Human Immunodeficiency Virus (HIV)-infected persons are at a higher risk of developing Tuberculous Meningitis (TBM). We aimed to estimate the prevalence of TBM-HIV co-infection. We systematically searched Pubmed/Medline, Embase and Cochrane library databases from January 1, 2000, to January 31, 2017, to find relevant studies. We employed the random-effects meta-analysis model to estimate the pooled prevalence of TBM-HIV co-infection. Twenty-six eligible studies showed the prevalence of HIV in TBM patients. In the pooled analyses, the prevalence of HIV was 30% (95% CI: 12-47) in patients with confirmed TBM, and 12.1% (95% CI: 7.3-19.2) in patients with suspected TBM. This study shows a high prevalence of TBM-HIV co-infection. Establishing proper diagnostic criteria and preventive measures for TBM infections could assist in the prevention and management of TBM infection, particularly TBM-HIV co-infection.

Synergistic effect of two antimicrobial peptides, Nisin and P10 with conventional antibiotics against extensively drug-resistant Acinetobacter baumannii and colistin-resistant Pseudomonas aeruginosa isolates.

BACKGROUND: Infections caused by drug-resistant strains of Acinetobacter baumannii and Pseudomonas aeruginosa are now a global problem that requires the immediate development of new antimicrobial drugs. Combination therapy and using antimicrobial peptides are two strategies with high potential to solve this issue. By these strategies, this study aimed to determine the antimicrobial effect of Nisin and P10 antimicrobial peptides on extensively drug-resistant Acinetobacter baumannii and colistin-resistant Pseudomonas aeruginosa isolates, and investigate the most effective combination of an antimicrobial peptide with an antibiotic. MATERIAL AND METHODS: This study was performed on five resistant clinical isolates and one standard strain for each kind of bacterium. First, the minimum inhibitory concentrations of two antimicrobial peptides (Nisin and P10) and five common antibiotics for the treatment of Gram-negative bacteria (ceftazidime, tobramycin, ciprofloxacin, doripenem, and colistin) was determined using Scanner-Assisted Colorimetric MIC Method. Then, the combination effect of P10+Nisin, P10+antibiotics, Nisin + antibiotics was investigated using checkerboard method. RESULTS: The MIC value of Nisin and P10 against studied pathogens were 64-256 and 8-32 µg/ml, respectively. P10+Nisin combination showed synergistic effect against standard strains and additive effect against drug-resistant clinical isolates. It was also found that the combination effect of P10+ceftazidim, P10+doripenem, and Nisin + colistin was synergistic in most cases. Nisin + tobramycin combination showed synergistic effect in exposure to standard strains, while the synergy is strain-dependent against drug-resistant clinical isolates. CONCLUSION: In conclusion, the synergism of Nisin + colistin and P10+ceftazidime/doripenem could be of great therapeutic value as antimicrobial drugs against infections caused by colistin-resistant P.aeruginosa and XDR A. baumannii.

Clinical characteristics and outcome of hospitalized COVID-19 patients with diabetes: A single-center, retrospective study in Iran.

AIM: To describe the epidemiological and clinical characteristics along with outcomes of hospitalized Coronavirus Disease 2019 (COVID-19) patients with and without diabetes. METHODS: This retrospective, single-center study included 595 consecutive hospitalized patients with confirmed COVID-19 at Baqiyatallah Hospital in Tehran, Iran, from February 26, 2020 to March 26, 2020. Demographic data, clinical, laboratory, and radiological findings were collected and compared between patients based on diabetes status. Complications and clinical outcomes were followed up until April 4, 2020. RESULTS: From among the 595 hospitalized patients with COVID-19, the median age was 55 years and 401 (67.4%) were male. The most common symptoms included fever (419 [70.4%]), dry cough (368 [61.8%]) and dyspnea (363 [61%]). A total of 148 patients (24.9%) had diabetes, and compared with patients without diabetes, these patients had more comorbidities (eg, hypertension [48.6% vs. 22.3%; P < 0.001]); had higher levels of white blood cell count, neutrophil count, C-reactive protein, erythrocyte sedimentation rate and blood urea nitrogen, and had a higher proportion of patchy ground-glass opacity in chest computed tomography findings (52.7% vs. 25.7%; P < 0.001). Significantly, patients with diabetes had more complications and needed more respiratory support than those without diabetes (P < 0.001). At the end of the follow-up, treatment failure and death was significantly higher in patients with diabetes compared to those without diabetes (17.8% vs. 8.7%; P = 0.003). CONCLUSION: COVID-19 patients with diabetes are at a higher risk of complications and a higher in-hospital mortality during hospitalization. Diabetes status of COVID-19 patients and frequent monitoring of glycemia would be helpful to prevent deteriorating clinical conditions.