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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Journal of Applied Biotechnology Reports
- نوع مقاله: Journal Article
- کلمات کلیدی: Prevalence,Diarrhea,Shigella species,Antibiotic Sensitivity Pattern
- چکیده:
- چکیده انگلیسی: Introduction: Shigellosis is a major health problem, especially in developing countries and in children under 5 years of age. The prevalence of Shigella species in a region can be considered as an indicator for hygiene level of that region. Due to the lack of an efficient vaccine, antibiotic therapy is the main strategy to combat the disease. In this study, the prevalence of the Shigella species and their antibiotic resistant pattern has been investigated.
Materials and Methods: A total of 300 diarrheal stool samples were collected from 4 different hospitals in Tehran during a period of 6 months June to November 2016. Bacterial identification and species discrimination was performed using biochemical and serotyping tests. Antibiotic resistance patterns of isolates were obtained using Bauer-Kirby method.
Results: 8.7% of all diarrheal cases were caused by Shigella species (5% by Shigella sonnei and 3.7% by Shigella flexneri). Antibiogram test revealed that the isolates were more sensitive or intermediate to ciprofloxacin (92.3%), while most of the isolates were resistant to tetracycline.
Conclusions: The prevalence of Shigella species has changed in Tehran. Since antibiotics are the treatment of choice to combat these pathogens, also, because of the emergence of the antibiotic resistance Shigella strains, there is a need for regularly updated regional antibiotic sensitivity patterns of the pathogen to guide therapy.- انتشار مقاله: 21-12-1396
- نویسندگان: Peyman Avakh Majalan,Abbas Hajizade,Shahram Nazarian,Mohammad Reza Pourmand,Kiana Amiri Siyavoshani
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Applied Biotechnology Reports
- نوع مقاله: Journal Article
- کلمات کلیدی: Escherichia coli O157: H7، Escherichia coli enterohemorhagic,Atypical Hemolytic Uremic Syndrome,Shiga-like Toxin,Watery Diarrhea
- چکیده:
- چکیده انگلیسی: Human infection by Escherichia coli enterohemorhagic (EHEC) can lead to watery diarrhea, blood flow, or hemolytic uremic syndrome (HUS). This syndrome occurs in 5 to 10 % of patients with E. coli O157: H7 infection. Children under the age of 5 years old and the elderly and people with immune deficiency are the most prone to severe complications caused by this pathogen. The entry of this bacteria that has the ability to produce Stx-like toxin causes gastrointestinal symptoms including diarrhea and intestinal mucus. This toxin is a hexamer protein with a molecular weight of 70.5 kDa and is composed of A and B units. The purpose of this study is to purify the Shiga-like toxin, which can be used to provide a diagnostic kit, antibody production and vaccine studies. First, E. coli O157: H7 was confirmed by PCR technique and cultured in LB medium. After centrifugation, the cell wall of the bacteria was destroyed by a sonication. Since the toxin is secreted both in the medium and intra-cellular, to increase the concentration of toxin, the precipitate and supernatant were mixed together then the mixture was precipitated with ammonium sulfate salt, it was dialyzed against the salt in a PBS buffer. The presence of toxin was confirmed by SDS-PAGE and Western Blot techniques. In order to confirm the toxicity of protein, supernatant, lysed sediment and a mixture of both were injected into mice groups. In this experiment, the yield of toxin production was 650 μg/ml and the final purity was 90%. Our results demonstrate that Shiga-like toxin (Stx) can be purified without chromatographic methods whit an acceptable purity and yield.
- انتشار مقاله: 03-06-1397
- نویسندگان: Javad Fathi,Firouz Ebrahimi,Shahram Nazarian,Yosef Tarverdizade
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Applied Biotechnology Reports
- نوع مقاله: Journal Article
- کلمات کلیدی: Bioinformatics,Virulence factors,Chimeric Protein,Enterohemorrhagic E. coli
- چکیده:
- چکیده انگلیسی: Enterohemorrhagic Escherichia coli (EHEC) strains are foodborne pathogens with importance in public health. The lack of effective clinical treatment, sequelae after infection and mortality rate in humans confirms the essential need for prophylactic and vaccines approaches. EspA, Tir, HcpA and Stx2 are major virulence factors for adherence and toxicity of EHEC, so an appropriate tetravalent immunogen consist of toxin subunit and crucial colonization factors was selected and constructed. Bioinfo[1]rmatic analyses of recombinant construction such as sequences choosing and optimizing, mRNA folding, physicochemical property in 2D and 3D structures, besides other immunoinformatics data like B-cell and T-cell epitopes and allergenicity of chimera were some reported according to the reliable servers. In silico assessment of the chimeric proteins demonstrated the desired model has a proper mRNA features, besides acceptable stability and solubility. This model is close to native proteins topologically, and all domains were found to have a high antigenic competency and surface accessibility. These results can be beneficial for the development of a chimeric immunogen against adherence and toxicity of EHEC in an animal model application.
- انتشار مقاله: 21-02-1396
- نویسندگان: Emad Kordbacheh,Shahram Nazarian,Milad Amerian
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Applied Biotechnology Reports
- نوع مقاله: Journal Article
- کلمات کلیدی: PCR-ELISA,Molecular detection,New Methods
- چکیده:
- چکیده انگلیسی: Due to the spread of infectious diseases, the existence of a rapid and sensitive detection method is necessary today. Polymerase chain reaction-enzyme linked immunosorbent assay (PCR-ELISA) is a simple manner for detection of microorganism. For example, bacteria, viruses, fungi and others based on nucleic acid sequence. A large number of samples can be screened by this technique simultaneously, so it is not time consuming and is a quick manner. The high sensitivity and specificity of PCR-ELISA make it a powerful technique by simple laboratory facilities. As a result it can be an excellent substituted manner for analysis and detectionin different various fields.
- انتشار مقاله: 21-03-1396
- نویسندگان: Fatemeh Tayebeh,Shahram Nazarian,Seyed Ali Mirhosseini,Jafar Amani
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Applied Biotechnology Reports
- نوع مقاله: Journal Article
- کلمات کلیدی: Klebsiella pneumoniae,16S rDNA,PCR-ELISA,Diagnostic Method
- چکیده:
- چکیده انگلیسی: Klebsiella pneumoniae is the most important infectious bacteria in Enterobacteriaceae family and the most common bacteria causing Urinary Tract Infection (UTI) after Escherichia coli. Therefore, accurate and rapid identification of this bacterium in hospital infection is very important.In this study, PCR-ELISA method was used for detecting Klebsiella pneumonia clinical strains. For this purpose, 16S rDNA gene based specific primers were designed and the DIG-labeled PCR products were bound to streptoavidin-coated wells of a microtiter plate and detected by anti-DIG–peroxidase conjugate. Biotin-labeled DNA probe specific for 16S rDNA gene was used in PCR-ELISA.Sensitivity and specificity of PCR-ELISA method were determined by using Enterobacteria strains. 16S rDNA of Klebsiella pneumoniae was amplified using gene specific primers resulted in a fragment of the 260 bp. The results of PCR-ELISA showed that this technique does not cross-react with the bacteria in their families as well as the sensitivity of 6.0 ng were evaluated.PCR-ELISA is known as an accurate and rapid method for detection of the infectious agents and therefore can be used as a suitable substitute for all the above aspects because it is quite a sensitive, specific, and rapid method for detection of the Klebsiella pneumoniae strains.
- انتشار مقاله: 26-06-1395
- نویسندگان: Fatemeh Tayebeh,Jafar Amani,Shahram Nazarian,Mehdi Moradyar,Seyed Ali Mirhosseini
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Applied Biotechnology Reports
- نوع مقاله: Journal Article
- کلمات کلیدی: Gold nanoparticles,Magnetic nanoparticles,Silica Nanoparticles,Quantum dots
- چکیده:
- چکیده انگلیسی: Recent investigations have been shown that inorganic nanomaterials including gold nanoparticles, nonporous and mesoporous silica nanoparticles, magnetic nanoparticles, and quantum dots have shown great potential in bioimaging, targeted drug delivery, and cancer therapies. Biocompatibility, ease of synthesis, and ease of surface functionalization are among the significant properties of nonporous and mesoporous silica nanoparticles in various nanomedicine applications. Quantum dots due to their high brightness, long-lasting, wide and continuous absorption spectra, and high fluorescent quantum yield are being used as the new optical probes for bioassays. In addition about gold nanoparticles, the ease of preparation, stability, low cytotoxicity, and high extinction coefficient of light from visible to NIR regions are some properties that introduced them as important candidates in cancer drug and nanocarrier development. As a specific type of inorganic nanomaterials, magnetic nanoparticles that exhibit super paramagnetic are capable of being used as contrast agents in magnetic resonance imaging, site-specific gene and drug delivery, and diagnostic agents in the presence of an external magnetic field. This review will present the physicochemical properties of most popular inorganic nanoparticles and their recent applications in sensing and drug delivery.
- انتشار مقاله: 27-01-1395
- نویسندگان: Keyvan Nasirzadeh,Shahram Nazarian,Seyed Mohammad Gheibi Hayat
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Applied Biotechnology Reports
- نوع مقاله: Journal Article
- کلمات کلیدی: vaccine,Adjuvants,Alum,MHC,Immunostimulating Complexe
- چکیده:
- چکیده انگلیسی: An adjuvant is a substance that is added to a vaccine to increase the body's immune response to the vaccine. Vaccines containing adjuvants are tested for safety in clinical trials before they are licensed for use. The basic action of adjuvants is stimulating adaptive immune responses. Adjuvants recently licensed for human utilization involve alum squalane oil or water emulsion, influenza virosomes, and few cytokines as IFN-γ and IL-2. Some adjuvants are currently under investigation such as DNA motifs, monophosphoryl lipid A, Cholera Toxin, E. coli heat Labile Toxin, Saponins, Immunostimulating complexes, liposomes, Flt3 ligand as a pleotropic glycoprotein, non-ionic block copolymers. This paper is an overview of most commonly used adjuvants, adjuvant mechanisms, adjuvant formulations and adjuvant limitations.
- انتشار مقاله: 24-06-1397
- نویسندگان: Seyed Mohammad Gheibihayat,Azam Sadeghinia,Shahram Nazarian,Zahra Adeli
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Applied Biotechnology Reports
- نوع مقاله: Journal Article
- کلمات کلیدی: Enterotoxigenic Escherichia coli,Colonization Factors,Heat-Labile Toxins,Heat Stable Toxin
- چکیده:
- چکیده انگلیسی: Millions of diarrheal disease is made by Enterotoxigenic E. coli (ETEC) each year, specifically in developing countries. In the pathogenesis of ETEC infections, the first phase is sticking of the bacterium to the minute intestinal epithelium, as a result of colonization factors (CFs) mediation and subsequently generate enterotoxins. These CFs in accordance with their structure are diverged into discrete groups. CFA/I and CS6 are two of the most typical CFs. CFA/I is a fimbriae consists of a superior subunit, CfaB and inferior subunit, CfaE. CS6 is non-fimbrial which includes two main subunits, CssA and CssB. The enterotoxins caused by ETEC are related to two eminent classes of heat-labile toxins (LT) and heat stable toxins (ST). LT is formed of five B subunits and a single enzymatically active A. Its B subunits tied up to the enteral GM1 ganglioside receptors in the intestinal epithelium and A subunit whose ADP-ribosylating activity culminates in cellular adenylcyclase activation and an increase in cAMP, efflux of chloride ions and water and succeeding watery diarrhea. Guanylatecyclase (GC) is receptor for the ST toxin. Intracellular levels of cyclic guanosine monophosphate (cGMP) increase when ST binds to GC. Such increase in cGMP permits activation of cystic fibrosis transmembrane conductance regulator (CFTR) by phosphorylation-dependent cGMP protein kinase II producing an escalation in salt and secretion of water and prevention of sodium absorption through h the apical Na/H channel.More information about the CFs and enterotoxins of pathogen leads to more founding of ETEC virulence, and the founding is important to designing an appropriate vaccine.
- انتشار مقاله: 25-10-1393
- نویسندگان: Seyed Mohammad Gheibi Hayat,Seyed Latif Mousavi Gargari,Shahram Nazarian,Hekmatallah Moradi Mogarmon
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Applied Biotechnology Reports
- نوع مقاله: Journal Article
- کلمات کلیدی: Recombinant vaccine,Polyclonal antibody,Diphtheria,diphtheria toxin,Mutated DTxA Chain
- چکیده:
- چکیده انگلیسی: Diphtheria is a fatal disease caused by exotoxin of Corynebacterium diphtheria. This toxin consists of two chains, catalytic chain (A) and binding (B) chain. By binding chain (B), the toxin binds to its receptor on numerous body cells such as myocardial, kidney and peripheral nerve cells. After entering, catalytic chain (A) inhibits protein synthesis and finally can cause cell death. At this time, the toxoid form of diphtheria toxin is used as vaccine. The aim of this study was the immunological analysis of the mutated synthetic catalytic subunit of diphtheria toxin in laboratory animals as a vaccine candidate, in addition to polyclonal antibody production and purification against diphtheria toxin. For this purpose the Dtx recombinant protein (with two mutant: A158G and G52E) was expressed using pET28a/DtxA plasmid in E. coli Bl21DE3 host. Then, recombinant protein, as a candidate vaccine, was extracted and purified. After evaluating and confirming the protein by SDS-PAGE and western blotting, immunization carried out in laboratory animals. Finally, followed by antibody titration by ELISA, antibody purification performed as well.The mutated recombinant protein prepared from an optimized expression was extracted and purified. Then, this protein was confirmed by SDS-PAGE and western blotting. ELISA results showed a satisfactory immunization of animals by this protein. Polyclonal antibody production and purification against diphtheria toxin was performed by G protein column and confirmed by ELISA. ELISA results showed a high titer of polyclonal antibody against diphtheria toxin in animal's serum after immunization by recombinant DTx protein.
- انتشار مقاله: 08-01-1397
- نویسندگان: Mohammad Ali Arefpour Torabi,Gholam Reza Olad,Shahram Nazarian,Jafar Salimian,Samaneh Khodi,Mohamad Javad Bagheripour
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Immunology
- نوع مقاله: Journal Article
- کلمات کلیدی:
- چکیده:
- چکیده انگلیسی: Background: Cholera disease caused by Vibrio cholerae remains a major cause of morbidity and mortality throughout the world. Various strategies with different proteins as immunogens have been tried for vaccine development, none of which have been sufficiently effective to preclude cholera. Chimeric proteins, with their ability to present multiple antigens at the same time, can play important roles in immunization. Objective: To evaluate the immunogenicity of a chimeric construct, comprised of OmpW and CtxB as immunogenic proteins of Vibrio cholera, in BALB/c mice. Methods: The construct was designed after bioinformatics assessments and then expressed in E.coli. Chimeric protein, OmpW, and CtxB were purified with Ni-NTA chromatography and confirmed by Western blotting. Mice were immunized with purified recombinant proteins. The antibody titers and specificity of the immune sera were then analyzed by ELISA and challenged on the pups of immunized mice with 1, 5 and 10 LD50. Mice ileal loop assay was also performed. Results: Significant differences were observed in antibody titers in immunized mice compared to the control groups. Infant mouse challenge was performed so as to compare the protective efficacies of the selected immunogen regimens. Of the Pups from dams immunized with chimeric protein which received 1 LD50, 75% survived. Pups belonging to PBS-immunized dams, experienced 100% mortality. The serum raised toward immunogenic construct, inhibited cholera toxin activity in ileal loop test up to 68%. Conclusion: Chimeric construct is able to induce the immune system and provide up to 75% inhibition of toxin activity against 1 LD50 of Vibrio cholerae.
- انتشار مقاله: 02-07-1397
- نویسندگان: Atina Vakili,Seyed Latif Mousavi Gargari,Shahram Nazarian,Jafar Amani
- مشاهده