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Introduction: MicroRNAs (miRNAs) are a group of small noncoding RNAs (ncRNAs) that post-transcriptionally control the expression of genes by binding and degrading their target mRNAs. miRNAs can function as possible tumor suppressors or oncogenes in various cancers. Lately, miRNAs application as a biomarker (prognosis and diagnosis) for different diseases has gained much attention. miRNAs exist in a stable form in several biological materials, including tissue, plasma, and serum. The noninvasive and easy screening of miRNAs in serum, blood, tissue, and other body fluids and acceptable stability make microRNA a noticeable factor as biomarkers in human malignancies. Material and Methods: In this review, we searched some online databases like Web of Science, Embase, and PubMed to find eligible manuscripts up to the end of 2021. Results: Abnormal expressions of these molecules are associated with the incidence of many illnesses like cancer. Therefore, they are candidates as a molecular tool for noninvasive tumor prognosis and diagnosis. In the current study, we introduce important miRNAs that may be used as prognostic and diagnostic markers in lung cancer patients. Conclusion: We summarized the latest reports about critical miRNAs related to the diagnosis and prognosis in lung patients.

Background: Reducing the burden of death due to infection is an urgent global public health priority. Previous studies have estimated the number of deaths associated with drug-resistant infections and sepsis and found that infections remain a leading cause of death globally. Understanding the global burden of common bacterial pathogens (both susceptible and resistant to antimicrobials) is essential to identify the greatest threats to public health. To our knowledge, this is the first study to present global comprehensive estimates of deaths associated with 33 bacterial pathogens across 11 major infectious syndromes. Methods: We estimated deaths associated with 33 bacterial genera or species across 11 infectious syndromes in 2019 using methods from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, in addition to a subset of the input data described in the Global Burden of Antimicrobial Resistance 2019 study. This study included 343 million individual records or isolates covering 11 361 study-location-years. We used three modelling steps to estimate the number of deaths associated with each pathogen: deaths in which infection had a role, the fraction of deaths due to infection that are attributable to a given infectious syndrome, and the fraction of deaths due to an infectious syndrome that are attributable to a given pathogen. Estimates were produced for all ages and for males and females across 204 countries and territories in 2019. 95% uncertainty intervals (UIs) were calculated for final estimates of deaths and infections associated with the 33 bacterial pathogens following standard GBD methods by taking the 2·5th and 97·5th percentiles across 1000 posterior draws for each quantity of interest. Findings: From an estimated 13·7 million (95% UI 10·9–17·1) infection-related deaths in 2019, there were 7·7 million deaths (5·7–10·2) associated with the 33 bacterial pathogens (both resistant and susceptible to antimicrobials) across the 11 infectious syndromes estimated in this study. We estimated deaths associated with the 33 bacterial pathogens to comprise 13·6% (10·2–18·1) of all global deaths and 56·2% (52·1–60·1) of all sepsis-related deaths in 2019. Five leading pathogens—Staphylococcus aureus, Escherichia coli, Streptococcus pneumoniae, Klebsiella pneumoniae, and Pseudomonas aeruginosa—were responsible for 54·9% (52·9–56·9) of deaths among the investigated bacteria. The deadliest infectious syndromes and pathogens varied by location and age. The age-standardised mortality rate associated with these bacterial pathogens was highest in the sub-Saharan Africa super-region, with 230 deaths (185–285) per 100 000 population, and lowest in the high-income super-region, with 52·2 deaths (37·4–71·5) per 100 000 population. S aureus was the leading bacterial cause of death in 135 countries and was also associated with the most deaths in individuals older than 15 years, globally. Among children younger than 5 years, S pneumoniae was the pathogen associated with the most deaths. In 2019, more than 6 million deaths occurred as a result of three bacterial infectious syndromes, with lower respiratory infections and bloodstream infections each causing more than 2 million deaths and peritoneal and intra-abdominal infections causing more than 1 million deaths. Interpretation: The 33 bacterial pathogens that we investigated in this study are a substantial source of health loss globally, with considerable variation in their distribution across infectious syndromes and locations. Compared with GBD Level 3 underlying causes of death, deaths associated with these bacteria would rank as the second leading cause of death globally in 2019; hence, they should be considered an urgent priority for intervention within the global health community. Strategies to address the burden of bacterial infections include infection prevention, optimised use of antibiotics, improved capacity for microbiological analysis, vaccine development, and improved and more pervasive use of available vaccines. These estimates can be used to help set priorities for vaccine need, demand, and development. Funding: Bill & Melinda Gates Foundation, Wellcome Trust, and Department of Health and Social Care, using UK aid funding managed by the Fleming Fund.

Background:: Pseudomonas(P.) aeruginosa is one of the leading causes of nosocomial infections. The pathogenicity of P. aeruginosa is related to its inherent antimicrobial resistance and the diverse virulence factors of this bacterium. Owing to the specific role of exotoxin A in P. aeruginosa pathogenesis, it is known as a promising therapeutic candidate to develop antibodies as an alternative to antibiotics. Objective:: The present study aimed to validate the interaction between a single-chain fragment variable (scFv) antibody identified from an scFv phage library against domain I exotoxin A by bioinformatic tools. Method:: For this, several bioinformatics tools, including Ligplot, Swiss PDB viewer (SPDBV), PyMOL, I-TASSER, Gromacs, and ClusPro servers were used to evaluate the interaction of scFv antibody with P. aeruginosa exotoxin A. The I-TASSER server was utilized to predict the function and structure of proteins. The interaction of two proteins was analyzed using ClusPro tools. The best docking results were further analyzed with Ligplot, Swiss PDB viewer, and PyMOL. Consequently, molecular dynamics simulation was utilized to predict the stability of the secondary structure of the antibody and the binding energy of the scFv antibody to the domain I of exotoxin A. Results:: As a result, we demonstrated that data from computational biology could provide protein-protein interaction information between scFv antibody/domain I exotoxin A and offers new insights into antibody development and therapeutic expansion. result: As a result, we demonstrated that data from computational biology could provide protein-protein interaction information between scFv antibody/domain I exotoxin A and offers new insights into antibody development and therapeutic expansion. Conclusions: In summary, a recombinant human scFv which is neutralizing exotoxin P. aeruginosa recommended as a promising treatment of infections caused by P. aeruginosa. Conclusions:: In summary, a recombinant human scFv capable of neutralizing P. aeruginosa exotoxin is recommended as a promising treatment for infections caused by P. aeruginosa.

Purpose The Coronavirus disease 2019 (COVID-19) pandemic is one of the most devastating global problems. Regarding the lack of disease-specific treatments, repurposing drug therapy is currently considered a promising therapeutic approach in pandemic situations. Recently, the combination therapy of Janus kinase (JAK) inhibitor baricitinib has been authorized for emergency COVID-19 hospitalized patients; however, this strategy's safety, drug-drug interactions, and cellular signaling pathways remain a tremendous challenge. Methods In this study, we aimed to provide a deep insight into the baricitinib combination therapies in severe COVID-19 patients through reviewing the published literature on PubMed, Scopus, and Google scholar databases. We also focused on cellular and subcellular pathways related to the synergistic effects of baricitinib plus antiviral agents, virus entry, and cytokine storm (CS) induction. The safety and effectiveness of this strategy have also been discussed in moderate to severe forms of COVID-19 infection. Results The severity of COVID-19 is commonly associated with a dysregulated immune response and excessive release of pro-inflammatory agents, resulting in CS. It has been shown that baricitinib combined with antiviral agents could modulate the inflammatory response and provide a series of positive therapeutic outcomes in hospitalized adults and pediatric patients (age ≥ two years old). Conclusion Baricitinib plus the standard of care treatment might be a potential strategy in hospitalized patients with severe COVID-19.

The escalating prevalence of coronavirus disease 2019 (COVID-19) worldwide, with an increased rate of morbidity and mortality, highlights an urgent need to develop more effective therapeutic interventions. Despite the authorized treatment against COVID-19 by the European Union (EU), the safety and effectiveness of this therapeutic strategy for a wide variety of patients have remained a significant challenge. In this respect, micronutrients such as vitamins and minerals, as essential factors, can be considered for improving the function of the immune system and accelerating the treatment procedure. Dietary supplements can attenuate vascular and inflammatory manifestations related to infectious diseases in large part due to their anti-inflammatory and antioxidant properties. Recently, it has been revealed that poor nutritional status may be one of the notable risk factors in severe COVID-19 infections. In the current review, we focus on the micronutrient therapy of COVID-19 patients and provide a comprehensive insight into the essential vitamins/minerals and their role in controlling the severity of the COVID-19 infection. We also discuss the recent advancements, challenges, negative and positive outcomes in relevance to this approach.

The CD147 / Cyp A interaction is a critical pathway in cancer types and an essential factor in entering the COVID-19 virus into the host cell. Melittin acts as an inhibitory peptide in cancer types by blocking the CD147/ Cyp A interaction. The clinical application of Melittin is limited due to weak penetration into cancer cells. TAT is an arginine-rich peptide with high penetration ability into cells widely used in drug delivery systems. This study aimed to design a hybrid peptide derived from Melittin and TAT to inhibit CD147 /Cyp A interaction. An amino acid region with high anti-cancer activity in Melittin was selected based on the physicochemical properties. Based on the results, a truncated Melittin peptide with 15 amino acids by the GGGS linker was fused to a TAT peptide (nine amino acids) to increase the penetration rate into the cell. A new hybrid peptide analog(TM) was selected by replacing the glycine with serine based on random point mutation. Docking results indicated that the TM peptide acts as an inhibitory peptide with high binding energy when interacting with CD147 and the CypA proteins. RMSD and RMSF results confirmed the high stability of the TM peptide in interaction with CD147. Also, the coarse-grained simulation showed the penetration potential of TM peptide into the DOPS-DOPC model membrane. Our findings indicated that the designed multifunctional peptide could be an attractive therapeutic candidate to halter tumor types and COVID-19 infection.

Melittin (MLT), a natural membrane-active component, is the most prominent cytolytic peptide from bee venom. Remarkable biological properties of MLT, including anti-inflammatory, antimicrobial, anticancer, anti-protozoan, and antiarthritic activities, make it an up-and-coming therapeutic candidate for a wide variety of human diseases. Therapeutic applications of MLT may be hindered due to low stability, high toxicity, and weak tissue penetration. Different bio-nano scale modifications hold promise for improving its functionality and therapeutic efficacy.In the current review, we aimed to provide a comprehensive insight into strategies used for MLT conjugations and modifications, cellular delivery of modified forms, and their clinical perspectives by reviewing the published literature on PubMed, Scopus, and Google Scholar databases. We also emphasized the MLT structure modifications, mechanism of action, and cellular toxicity.Developing new analogs and conjugates of MLT as a natural drug with improved functions and fewer side effects is crucial for the clinical translation of this approach worldwide, especially where the chemicals and synthetic drugs are more expensive or unavailable in the healthcare system. MLT-nanoconjugation may be one of the best-optimized strategies for improving peptide delivery, increasing its therapeutic efficacy, and providing minimal nonspecific cellular lytic activity. [Figure: see text].

Long non-coding RNAs (lncRNA) have been emerged as a novel class of molecular regulators in cancer. They are dysregulated in many types of cancer; however, there is not enough knowledge available on their expression and functional profiles. Lung cancer is the leading cause of the cancer deaths worldwide. Generally, lncRNAs may be associated with lung tumor pathogenesis and they may act as biomarkers for the cancer prognosis and diagnosis. Compared to other invasive prognostic and diagnostic methods, detection of lncRNAs might be a user-friendly and noninvasive method. In this review article, we selected 27 tumor-associated lncRNAs by literature reviewing to further discussing in detail for using as diagnostic and prognostic biomarkers in lung cancer. Also, in an in silico target analysis, the "Experimentally supported functional regulation" approach of the LncTarD web tool was used to identifying the target genes and regulatory mechanisms of the selected lncRNAs. The reports on diagnostic and prognostic potential of all selected lncRNAs were discussed. However, the target genes and regulatory mechanisms of the 22 lncRNAs were identified by in silico analysis and we found the pathways that are controlled by each target group of lncRNAs. They use epigenetic mechanisms, ceRNA mechanisms, protein interaction and sponge mechanism. Also, 10, 23, 5, and 28 target genes for each of these mechanisms were identified, respectively. Finally, each group of target genes controls 50, 12, 7, and 2 molecular pathways, respectively. In conclusion, LncRNAs could be used as biomarkers in lung cancer due to their roles in control of several signaling pathways related to lung tumors. Also, it seems that lncRNAs, which use epigenetic mechanisms for modulating a large number of pathways, could be considered as important subjects for lung cancer-related diagnostic and prognostic biomarkers.

Genome engineering technology is of great interest for biomedical research that enables scientists to make specific manipulation in the DNA sequence. Early methods for introducing double-stranded DNA breaks relies on protein-based systems. These platforms have enabled fascinating advances, but all are costly and time-consuming to engineer, preventing these from gaining high-throughput applications. The CRISPR-Cas9 system, co-opted from bacteria, has generated considerable excitement in gene targeting. In this review, we describe gene targeting techniques with an emphasis on recent strategies to improve the specificities of CRISPR-Cas systems for nuclease and non-nuclease applications.

Background: Angiogenesis is a critical physiological process that plays a key role in tumor progression, metastatic dissemination, and invasion. In the last two decades, the vascular endothelial growth factor (VEGF) signaling pathway has been the area of extensive researches. VEGF executes its special effects by binding to vascular endothelial growth factor receptors (VEGFRs), particularly VEGFR-2. Objective: The inhibition of VEGF/VEGFR2 interaction is known as an effective cancer therapy strategy. The current study pointed to design and model an anti-VEGF peptide based on VEGFR2 binding regions. Method: The large-scale peptide mutation screening was used to achieve a potent peptide with high binding affinity to VEGF for possible application in inhibition of VEGF/VEGFR2 interaction. The AntiCP and Peptide Ranker servers were used to generate the possible peptides library with anticancer activities and prediction of peptides bioactivity. Then, the interaction of VEGF and all library peptides were analyzed using Hex 8.0.0 and ClusPro tools. A number of six peptides with favorable docking scores were achieved. All of the best docking scores of peptides in complexes with VEGF were evaluated to confirm their stability, using molecular dynamics simulation (MD) with the help of the GROMACS software package. Results: As a result, two antiangiogenic peptides with 13 residues of PepA (NGIDFNRDFFLGL) and PepC (NGIDFNRDKFLFL) were achieved and introduced to inhibit VEGF/VEGFR2 interactions Conclusions: In summary, this study provided new insights into peptide-based therapeutics development for targeting VEGF signaling pathway in tumor cells. PepA and PepC are recommended as potentially promising anticancer agents for further experimental evaluations.

Background: Overexpression of EGFR is associated with carcinogenesis in more than 70% of head and neck cancers. Anti-EGFR monoclonal antibodies bind to the extracellular domain of EGFR and block the EGFR downstream signaling pathway, which results in the suppression of the growth of the tumor cells. Escherichia coli is the preferred system for expressing various recombinant proteins, including single chain antibodies, but the formation of inclusion bodies negatively affects the efficacy of this system. Several strategies have been suggested to solve this problem, notably the utilization of molecular chaperones. Objectives: In this study, we attempted to increase the soluble expression of huscfv antibody via co-expression with the cytoplasmic chaperones. Materials and Methods: To achieve this purpose, chaperones plasmids pG-KJE8, pGro7, pKjE7, pTf16 and pG-Tf2 encoding cytoplasmic chaperones were co-expressed with the humanized anti-EGFR scFv construct in E. coli. Different temperatures, incubations times, and concentrations of IPTG were used to produce an active antibody with the highest solubility. Results were analyzed by SDS-PAGE. Soluble huscFv was purified by Ni-NTA column and the biologic activity of the recombinant protein was determined by ELISA. Result: The results indicated that the highest concentrations of humanized anti-EGFR scFv were obtained by co-expression of huscFv via chaperone plasmid pG-KJE8 with 0.2 mM concentration of inducer (IPTG), culture temperature of 25 °C, and 4 h incubation time after induction. Conclusion: In conclusion, co-expression with chaperones could be used as an efficient strategy to produce soluble active ScFvs in E. coli.

Objectives: Staphylococcus aureus (S. aureus) is the most prevalent cause of skin infections, especially in colonized individuals. Panton–Valentine leukocidin (PVL) and Arginine catabolic mobile element (ACME) are known as the most common virulence factors of S. aureus. This cross-sectional study was conducted to examine the prevalence of ACME-arcA and PVL genes among S.aureus isolates in the student population. Nasal swab samples were randomly collected from 400 healthy students from Tabriz, Iran. The antibiotic resistance pattern of S.aureus isolates was examined by the disk diffusion method. The presence of ACME-arcA, PVL, and mecA genes was detected by PCR reaction.Results: overall, 15% (60/400) students were nasal carriage of S. aureus and 2.75 % (11/400) were MRSA carriage. The frequency of mecA, ACME-arcA, and PVL genes was 54.54% (36/60), 46.66% (28/60), and 16.66% (10/60) respectively. The prevalence of ACME-arcA and PVL genes was independent of gender (P =0.142, P=0.337, respectively). A notable association was observed between the existence of ACME-arcA gene and the frequency of mecA gene (P PVL was independent on mecA. These findings highlight the necessity of monitoring nasal carriers in a healthy community to prevent subsequent infections.

The development of recombinant immunotoxins (RITs) as a novel therapeutic strategy has made a revolution in the treatment of cancer. RITs result from the fusion of antibodies to toxin proteins for targeting and eliminating cancerous cells by inhibiting protein synthesis. Despite indisputable outcomes of RITs regarding inhibition of multiple cancer types, high immunogenicity has been known as the main obstacle in the clinical use of RITs. Various strategies have been proposed to overcome these limitations, including immunosuppressive therapy, humanization of the antibody fragment moiety, generation of immunotoxins originated from endogenous human cytotoxic enzymes, and modification of the toxin moiety to escape the immune system. This paper is devoted to review recent advances in the design of immunotoxins with lower immunogenicity.

Background: Angiogenesis is one of the critical physiological processes, by which the new blood vessels are generated from the pre-existing vessels in the early stage of vasculogenesis. While normal angiogenesis is critical for development and tissue growth, pathologic angiogenesis is important for the growth and spread of cancers by supplying nutrients and oxygen as well as providing a conduit for distant metastasis. In the last two decades, angiogenesis has been the area of extensive researches, indicating antiangiogenic target therapy as an effective strategy for cancer therapy. At present, this field has become a major avenue for research and development of novel therapeutics. Objective: This review is dedicated to an updated review of the most prominent antiangiogenic agents, emphasizing the novel advancements and their applications, in particular, in the fields of antibodies, peptides, vaccines, endogenous inhibitors, Nanoparticles (NPs), antiangiogenic oligonucleotides and small molecules. Also, the potential role of 3D microfluidic models as an affordable and time-saving tool for angiogenesis investigations are discussed. Methods: Firstly, we collected and summarized new developments that have occurred in all review and research articles in databases. Then, we used important keywords related to antiangiogenic target therapy and their applications for retrieval of most relevant data. Results: This review is based on recent research and review articles and intended to cover all newly discovered agents inhibiting tumor angiogenesis and in particular, VEGF. Conclusion: New research studies have shown that anti-angiogenesis agents especially, in the form of combination therapy are effective in various cancers treatment.

Objectives: Brucellosis is a worldwide zoonotic disease with high morbidity in the absence of treatment. The early diagnosis of brucellosis is efficient to prevent chronic infections. The aim of this study is evaluation of nested PCR efficiency in comparison with conventional methods for diagnosis of human brucellosis. A total of 120 patients with brucellosis symptoms were included in this study. Serological and microbiological tests and nested PCR were used for detection of Brucella bacteria. Results: Based on serological tests, 60.83% (73/120) of individuals were positive for brucellosis which only 8.33% of cases were confirmed by blood culture. Among them, 55% of cases were positive in serum agglutination test (SAT≥1:160) and Coombs (C-SAT≥1:160) tests. Furthermore, 7 negative SAT cases were positive in C-SAT as evidence for chronic brucellosis. Also, 68.18% and 56.06% of SAT positive samples were positive in blood nested PCR and serum nested PCR respectively. The sensitivity of blood nested PCR was more than serum nested PCR, SAT≥1:160 and blood culture (P

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is often the cause of a wide broad of infections ranging from minor skin infections to serious infections such as toxic shock syndrome (TSS) in hospital and community settings. Toxic shock syndrome toxin 1 (TSST-1) superantigen is the main cause of TSS. Objectives: The current study aimed to determine the frequency of MRSA carriage and TSST-1 virulence factor among high school students. Methods: A total of 400 nasal swab samples were randomly collected from male and female students of six different high schools in Tabriz, Iran. After confirmation of S. aureus strains by standard biochemical tests, the antibiotic sensitivity pattern of the isolates was determined by the disk diffusion method. The presence of mecA and TSST-1 genes was examined by PCR. Results: From 400 students, 15% (n = 60) were positive for S. aureus. Antimicrobial susceptibility testing was performed using 12 antibiotic disks. Based on the results, 100% of the isolates were resistant to ampicillin while all of them were sensitive to vancomycin. Moreover, 18.34% of the S. aureus isolates were resistant to cefoxitin and 11.67% were resistant to oxacillin. The presence of the mecA gene was confirmed in 54.54% of the cases. These results indicated oxacillin-susceptible mecA-positive S. aureus (OS-MRSA) colonization among students. Based on the PCR results, only one of the MRSA isolates belonging to a female student was positive for the TSST-1 gene. Conclusions: Our findings highlight the spread of OS-MRSA among the healthy population in Tabriz, Northwest of Iran. Nevertheless, a combination of genetic and phenotypic tests is needed to accurately detect MRSA.

Escalating antibiotic resistance is now a serious menace to global public health. It may be led to the emergence of "postantibiotic age" in which most of infections are untreatable. At present, there is an essential need to explore novel therapeutic strategies as a strong and sustainable pipeline to combat antibiotic-resistant infections. This review focuses on recent advances in this area including therapeutic antibodies, antimicrobial peptides, vaccines, gene therapy, genome editing, and phage therapy for tackling drug-resistant infections.

Background Increasing prevalence of multidrug-resistant (MDR) A. baumannii isolates coupled with survival ability in adverse conditions has made this pathogen a serious threat to global health. A cross-sectional study was conducted to examine biofilm forming genes and antibiotic resistance profiles of A. baumannii clinical isolates in Tabriz, North-west Iran. Methods A total of 100 A. baumannii strains were isolated from hospitalized patients in Tabriz city, northwest of Iran. The isolates were detected through standard microbiological and biochemical tests and blaOXA-51 detection. After the examination of antibiotic resistance profile, the biofilm formation capacity was investigated by a microtitre plate assay. The presence of bap and ompA genes related to biofilm-forming was examined by PCR reaction. Results The highest resistance rate was observed against meropenem (100%), tigecycline (100%), and ceftizoxime (99%), respectively. Analysis for resistance to different antibiotic classes revealed that 100% of the isolates were multidrug-resistant (MDR), and 79% of them were extensively drug-resistant (XDR). Overall, 84% of the isolates were able to produce biofilm that 3.57% (3/84) of them were strongly capable to form a biofilm. All of the strong biofilm-forming A. baumannii isolates were found as XDR. Also, 100% of the isolates had the ompA gene, and 89% of them were positive for the bap gene. Conclusion Our findings revealed a high prevalence of biofilm-forming and biofilm-related genes of bap and ompA in MDR A. baumannii strains in the study region. Based on our results, there is a correlation between the presence of the bap gene and biofilm formation.

Phage display technology as a selection-based system is an attractive method for evolution of new biological drugs. Unique ability of phage libraries for displaying proteins on bacteriophage surfaces enable them to make a major contribution in diverse fields of researches related to the diagnosis and therapy of diseases. One of the great challenges facing researchers is the modification of phage display technology and the development of new applications. This article reviews the molecular basis of phage display library, and summarizes the novel and specific applications of this technique in the field of biological drugs development including therapeutic antibodies, peptides, vaccines, and catalytic antibodies.

Introduction and objectives Methicillin-resistant Staphylococcus (S.) aureus (MRSA) is responsible for clinical infections ranging from minor skin infections to severe infections. Alpha hemolysin (hla) and beta hemolysin (hlb) are the most common virulence factors in S. aureus. The current study was aimed to detect hla and hlb genes in nasal methicillin-resistant S. aureus isolates in the student population. Materials and method A total of 1420 nasal samples were obtained from 23 different high schools in Tabriz city. After confirmation of S. aureus strains by standard biochemical tests, the antibiotic resistance pattern was determined by the disk diffusion method. The presence of mecA, hla, and hlb genes was examined by PCR reaction. Result Of 1420 samples, 14.30% (203 cases) were positive S. aureus. Among them, 18.72% (38/203) of the isolates were MRSA based on disk diffusion. Based on results, more than 90% of the isolates were susceptible to chloramphenicol, ciprofloxacin, and cefazolin, suggesting that these drugs may indicate better function to treat MRSA infections. The existence of mecA, hla, and hlb genes was observed in 56.16%, 88.18%, and 62.07%, respectively. There is a significant relationship between the prevalence of hla and frequency of the macA gene (p = 0.049), while the rate of hlb was independent on mecA. Discussion and conclusion The increasing prevalence of hla/hlb positive S. aureus isolates indicates an essential need to monitor nasal carriers in a healthy community to prevent subsequent infections.

Yeasts are outstanding hosts for the production of functional recombinant proteins with industrial or medical applications. Great attention has been emerged on yeast due to the inherent advantages and new developments in this host cell. For the production of each specific product, the most appropriate expression system should be identified and optimized both on the genetic and fermentation levels, considering the features of the host, vector and expression strategies. Currently, several new systems are commercially available; some of them are private and need licensing. The potential for secretory expression of heterologous proteins in yeast proposed this system as a candidate for the production of complex eukaryotic proteins. The common yeast expression hosts used for recombinant proteins' expression include Saccharomyces cerevisiae, Pichia pastoris, Hansenula polymorpha, Yarrowia lipolytica, Arxula adeninivorans, Kluyveromyces lactis, and Schizosaccharomyces pombe. This review is dedicated to discuss on significant characteristics of the most common methylotrophic and non-methylotrophic yeast expression systems with an emphasis on their advantages and new developments.

Objectives Methicillin resistant Staphylococcus (S.) aureus colonization is one of the main causes of serious infections in hemodialysis patients. This cross-sectional study was performed to examine prevalence of MRSA colonization and evaluation of risk factors in hemodialysis patients. A total of 560 swab samples from nasal, the skin around catheter and throat were collected from 231 hemodialysis patients in Tabriz. The standard biochemical tests were used for identification of S. aureus isolates. Antimicrobial susceptibility profile was determined against 11 antibiotics by the disk diffusion method. Phenotypic test of S. aureus was performed using novobiocin 30 μg/disc, and methicillin sensitivity test was performed by cefoxitin 30 μg/disc. Results Overall, 50.65% (118/231) hemodialysis patients were positive for S. aureus which 34.93% (80/231) of patients were MRSA carriage. The MRSA colonization in patients with a catheter (44.06%) was more than individuals utilizing a fistula (24.57%, p = 0.030). Among sampling sites, the highest MRSA was related to nasal samples (30.70%, p

Objectives During recent years, multidrug-resistant Acinetobacter baumannii strains have become a serious threat to global health. Furthermore, the appearance of new resistant markers, such as New Delhi metallo-β-lactamase (NDM-1) with the ability to hydrolyze a wide range of β-lactams has limited the treatment process. Aim This cross-sectional study was aimed to detect blaOXA-23 and blaNDM-1 carbapenemase genes among A. baumannii clinical isolates in Tabriz, North-west Iran. Methods A total of 100 A. baumannii isolates were collected from Imam Reza Hospital of Tabriz city. Isolates were recognized by standard biochemical tests and molecular detection of blaOXA-51 gene. Antimicrobial susceptibility profile was examined via the disk diffusion method. The presence of blaOXA-23 and blaNDM-1 resistance genes was determined by PCR and sequencing. Results Overall, the highest resistance rate was against ciprofloxacin (95%), aztreonam (90%) and imipenem (82%) whereas the highest susceptibility was detected to gentamicin (65%). The frequency of MDR and XDR strains was 76% and 30%, respectively. All of carbapenem resistant isolates were carrying blaOXA-23 gene and only one of them (1%) was positive for blaNDM-1 resistance gene. Conclusion Our results are indicating a high incidence of blaOXA-23 like gene and the emergence of blaNDM-1 gene as a resistance factor to almost all antibiotics among the carbapenem resistant A. baumannii strains in our study region.

Pseudomonas aeruginosa is an opportunistic bacterium that causes serious nosocomial infection in immunocompromised patients. The aim of this study was to prepare a fusion protein consisting of exotoxin A (ExoA) and flagellin (Fla) from P. aeruginosa and to evaluate its potential as a vaccine candidate against P. aeruginosa infection. The genes encoding for ExoA and Fla proteins were cloned in-frame and expressed in Escherichia coli. The recombinant ExoA–Fla fusion protein was purified by Ni-NTA affinity chromatography. Mice were immunized subcutaneously with ExoA, Fla, and ExoA–Fla fusion proteins, and the humoral immune response was evaluated by ELISA method. The immunized and control group mice were challenged with a 2× LD50 (7.5 × 107 CFU) of P. aeruginosa for the protection assay. The results indicated that vaccination with Fla, ExoA, and ExoA–Fla fusion proteins produced a significant amount of specific immunoglobulin G antibodies. Immunization of mice with ExoA–Fla fusion protein showed significant protection against intraperitoneal challenge with 7.5 × 107 CFU (2× LD50) P. aeruginosa. Results of this study suggest that recombinant ExoA–Fla fusion protein is a highly immunogenic protective protein showing promise as a vaccine candidate against P. aeruginosa.

Immunotoxins are a novel class of cancer therapeutics that contains a cytotoxic agent fused to a targeting moiety. Various toxic agents from different sources are used in immunotoxin development, including bacterial, plant and human origin cytotoxic elements. Although bacterial and plant-derived toxins are highly toxic and commonly used in immunotoxins, their immunogenicity for human restricted their application in cancer therapy. Here, we discuss the advantages and limitations of bacterial toxins such as Pseudomonas and Diphtheria toxins, plant toxins such as ricin and gelonin, and some endogenous protein of human origin such as RNases and Granzymes. This article will also review different generations of immunotoxins with special focus on immunotoxins which are under clinical trials or approved for clinical use. Finally, current deimmunization strategies for development of new less-immunogenic recombinant immunotoxins will be discussed.mAbs: Monoclonal antibodies; EF2: elongation factor 2; ITs: Immunotoxins; DT: Diphtheria toxin; PE: Pseudomonas exotoxin; dgA: de-glycosylated A-chain of ricin; rGel: recombinant de-glycosylated form of gelonin; NKC: natural killer cells; HTR: human transferrin receptor; EGF: epidermal growth factor; GM-CSF: granulocyte-macrophage colony-stimulating factor; DAB389: truncated Diphtheria toxin; B-CCL: B-cell chronic lymphocytic leukemia; RCC: renal cell carcinoma; GVHD: Graft-versus-host disease; EGFR: epidermal growth factor receptor; AML: acute myeloid leukemia; Fab: fragment antigen-binding; dsFv: disulfide-stabilized fragment variable; scFv: single-chain fragment variable; B-ALL: B-lineage Acute Lymphoblastic Leukemia; Fv: fragment variable; HCL: hairy cell leukemia; IL-2R: Interleukin-2 receptor; CR: complete response; CLL: chronic lymphocytic leukemia; ATL: adult T-cell leukemia; DARPins: designed Ankyrin repeat proteins; pmol: picomolar; HAMA: human-anti mouse antibody.

Overexpression of epidermal growth factor receptor (EGFR) plays a significant role in the development and metastasis of many solid tumors. Strategies based on anti-EGFR immunotoxins have shown promising results in several studies, but immunogenicity of antibody and toxin moieties is a limitation of this type of therapeutics. In the present study, a novel humanized anti-EGFR immunotoxin (huscFv-PE25) was developed by genetic fusing of a humanized anti-EGFR single-chain variable fragment (huscFv) with a modified Pseudomonas aeruginosa exotoxin A (PE25KDEL). The reactivity and toxicity of this immunotoxin with tumor cells were assessed by dot-blot, enzyme-linked immunosorbent assay, and MTT procedures. Results of enzyme-linked immunosorbent assay and dot-blot assay indicated that the immunotoxin recognizes and efficiently binds to EGFR-overexpressing tumor cells. MTT assay showed a specific growth-inhibitory effect of huscFv-PE25 on EGFR-overexpressing A431 cells, without any inhibitory effect on EGFR-negative cells. In conclusion, the results of this study indicated that huscFv-PE25 can recognize and exert an inhibitory effect on EGFR-overexpressing cancer cells, despite its smaller size and lower immunogenicity. This may provide a basis for the development of novel clinical therapeutic agents against EGFR-overexpressing tumor cells.

EGFRvIII, a mutant form of epidermal growth factor receptor is highly expressed in glioblastoma, carcinoma of the breast, ovary, and lung but not in normal cells. This tumor specific antigen has emerged as a promising candidate for antibody based therapy of several cancers. The aim of the present study was isolation and characterization of a human single chain antibody against EGFRvIII as a promising target for cancer therapy. For this, a synthetic peptide corresponding to EGFRvIII protein was used for screening the naive human scFv phage library. Selection was performed using a novel screening strategy for enrichment of rare specific clones. After five rounds of screening, six positive scFv clones against EGFRvIII were selected using monoclonal phage ELISA, among them, a clone with an amber mutation in VH CDR2 coding sequence showed higher reactivity. The mutation was corrected through site directed mutagenesis and then scFv fragment was expressed after subcloning into the bacterial expression vector. Expression in BL21 pLysS resulted in a highly soluble scFv appeared in soluble fraction of E. coli lysate. Bioinformatic in silico analysis between scFv and EGFRvIII sequences confirmed specific binding of desired scFv to EGFRvIII in CDR regions. The specific reactivity of the purified scFv with native EGFRvIII was confirmed by cell based ELISA and western blot. In conclusion, human anti- EGFRvIII scFv isolated from a scFv phage library displayed high reactivity with EGFRvIII. The scFv isolated in this study can be the groundwork for developing more effective diagnostic and therapeutic agents against EGFRvIII expressing cancers.

Epidermal growth factor receptor (EGFR) as a transmembrane tyrosine kinase receptor frequently overexpresses in tumors with epithelial origin. The L2 domain from extracellular part of EGFR is involved in ligand binding and the blockage of this domain prevents activation of related signaling pathways. This study was aimed to develop a novel human scFv against EGFR L2 domain as a promising target for cancer therapy. The L2 recombinant protein was purified and used for panning a human scFv phage library (Tomlinson I). In this study, a novel screening strategy was applied to select clones with high binding and enrichment of rare specific phage clones of the L2 protein. After five biopanning rounds several specific clones were isolated which among them one phage clone with high binding was purified for further analysis. The specific interaction of selected clone against target antigen was confirmed by ELISA and western blotting. Immunofluorescence staining showed that purified scFv binds to A431 cells surface, displaying EGFR surface receptor. In the present study, we isolated for the first time a novel human scFv against EGFR L2 domain. This study can be the groundwork for developing more effective diagnostic and therapeutic agents against EGFR overexpressing cancers using this novel human anti-L2 ScFv.

Phage display is a prominent screening technique for development of novel high affinity antibodies against almost any antigen. However, removing false positive clones in screening process remains a challenge. The aim of this study was to develop an efficient and rapid method for isolation of high affinity scFvs by removing NSBs without losing rare specific clones. Therefore, a novel two rounds strategy called invert biopanning was developed for isolating high affinity scFvs against EGFRvIII antigen from human scFv library. The efficiency of invert biopanning method (procedure III) was analyzed by comparing with results of conventional biopanning methods (procedures I and II). According to the results of polyclonal ELISA, the second round of procedure III displayed highest binding affinity against EGFRvIII peptide accompanied by lowest NSB comparing to other two procedures. Several positive clones were identified among output phages of procedure III by monoclonal phage ELISA which displayed high affinity to EGFRvIII antigen. In conclusion, results of our study indicate that invert biopanning is an efficient method for avoiding NSBs and conservation of rare specific clones during screening of a scFv phage library. Novel anti EGFRvIII scFv isolated could be a promising candidate for potential use in treatment of EGFRvIII expressing cancers.

Epidermal growth factor receptor (EGFR) plays an important role in cell growth, multiplication and differentiation. Over expression of EGFR is associated with carcinogenesis and seen in variety of cancers. Anti-EGFR monoclonal antibodies can block EGFR downstream signaling pathway resulting in inhibition of uncontrolled cell proliferation. Antibody fragments have a variety of advantages. In comparison to full length antibodies they have smaller size and therefor exhibit better tumor penetration ability. The aim of this study was to prepare a single domain antibody to target extracellular domain of EGFR. mRNA was extracted from C225 hybridoma cells producing anti-EGFR antibody and subjected to reverse transcription reaction (RT-PCR) to obtain cDNA molecules encoding VH domain of mAb C225. The cDNA encoded VH domain was in frame introduced into the pET-22b(+) vector and expressed in BL21 (DE3) bacterial cells. The resultant antibody was purified via Ni- NTA column and its reactivity was assessed by ELISA and western blot techniques using A431 cell lysate. Analysis by ELISA revealed that this single domain antibody was able to bind EGFR on A431cells. This result was further confirmed by western blotting. In conclusion, the results of this study indicated that single domain antibody can identify and bind to EGFR of A431 carcinoma cells. This recombinant fragment antibody would potentially be used for targeting of cancer cells with high EGFR expression.

Recombinant antibodies are increasingly being employed as therapeutic agents especially in combination with anti-cancer drugs. The single-chain antibody fragments are small antigen-binding proteins which provide the most commonly used antibody formats for diagnostic and therapeutic purposes. These antibody fragments have more rapid tumor penetration and clearance from the serum relative to full-length monoclonal antibodies. There are in vitro antibody-display technologies such as phage display, cell surface display, ribosome display and mRNA display that can be used to isolate high specificity and affinity single-chain antibodies against a wide variety of targets. We review these strategies for generation of stable and active antibody fragments in the present article.

Parasite of the genus Leishmania is reliant on the salvage pathway for recycling of ribonucleotides. A class I nuclease enzyme also known as P4 nuclease is involved in salvage of purines in cutaneous Leishmania species but the relevant enzymes have not been characterized in Leishmania infantum (L. infantum). The aim of this study was to clone and characterize the gene encoding class I nuclease in L. infantum. DNA extracted from L. infantum was used for amplification of P4 nuclease gene (Li-P4) by PCR. The product was cloned, sequenced, and expressed in E. coli for further characterization. Analysis of the sequence of Li-P4 revealed that the gene consists of an ORF of 951 bp. Sequence similarity analysis indicated that Li-P4 has a high homology to relevant enzymes of other kintoplastids with the highest homology (88%) to p1/s1 class I nuclease from L. donovani. Western blotting of antirecombinant Li-P4 with promastigote and amastigote stages of L. infantum showed that this nuclease is present in both stages of parasite with higher expression in amastigote stage. The highly conserved nature of this essential enzyme in Leishmania parasites suggests it as a promising drug target for leishmaniasis.

Helicobacter pylori is a major gastroduodenal pathogen and its seropositivity is associated with increased risk of development of human active chronic gastritis, peptic and duodenal ulcer and gastric cancer. The aim of this study was to determine the seroprevalence of H. pylori infection among subjects with gastrointestinal problems. A total of 339 serum samples collected from 114 male and 225 female were screened for detection of anti H. pylori IgG, IgA and IgM using commercial ELISA tests. The overall seropositivity rates were as follows: anti H. pylori IgG 73%; anti H. pylori IgM 43% and anti H. pylori IgA 25%. Seropositivity of anti H. pylori IgG increased markedly with age and highest infection rate (96%) was seen in individuals 40 to 50 years old. Anti H. pylori IgA was also correlated with increasing age. No association was detected between H. pylori seropositivity, gender and inflammatory laboratory parameters. This study revealed the high prevalence of H. pylori infection among symptomatic subjects in northwest of Iran. Key words: Helicobacter pylori, seroprevalence, IgG, IgA, IgM.