فهرست مطالب

  • Volume:5 Issue:14, 2018
  • تاریخ انتشار: 1397/08/12
  • تعداد عناوین: 8
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  • Wiwanitkit V*, Yasri S Pages 1-3
    Vaccination is a useful primary prevention against infectious diseases. In several countries, many infections are endemic and vaccines are usually provided free of charge by the local governments to the people. For vaccination, the assessment for the contraindication which is usually based on clinical history taking, is the primary requirement. Here, the experiences on a recent situation of free influenza vaccination is discussed. This review was based on the clinical history of 200 local patients who had attended a medical center in Bangkok, Thailand, during June 2018, asking for free influenza vaccination according to the local Tha
    Keywords: Reliable, Vaccine, Recipient
  • Afrough P, Vosogh M, Asadi Karam MR, Behrouzi A, Mardani G, Siadat SD Pages 4-6
    Introduction
    As the causative agent of meningitis, Neisseria meningitidis has different serogroups. The purpose of this study was to investigate the molecular properties of N. meningitidis strains among Iranian cases.
    Methods
    450 samples were collected from children under 5 years of age. Detection of Neisseria genus was done by phenotypic and genotypic methods. Multiplex PCR was used to identify the serogroups of N. meningitides. The sequencing of variable regions of porA gene was performed for detection of the subserogroups.
    Results
    From 137 (30.44%) Neisseria isolates, 4 isolates (0.88%) belonged to N. meningitidis and 133 isolates (29.55%) belonged to other species. Multiplex PCR results showed that one isolate belonged to serogroup A while 3 belonged to serogroup B. The analysis of amplified VR1 and VR2 variable regions of porA showed 100% identity of the serogroup A strain with strain BZ83N and the serogroup B strains with strain 528 of N. meningitidis . In accordance with other findings in Asia, serogroups A and B were the most prevalent serogroups of N. meningitidis. Sequencing of variable regions of porA could identify the subserogroups of the isolates.
    Conclusion
    sequencing of porA could be a valuable method for identification of N. meningitidis strains to be used in epidemiological studies as well as improved vaccine designs.
    Keywords: Neisseria meningitidis, porA, sequencing, PCR, typing
  • Marandi V, Tabatabaeian SH, Jafari P, Azarnoosh M Pages 7-13
    Presently, vaccines development and production has gained more importance due to their influence on topics such as the society's health system and economy, as well as the bio-security issues and the defense affairs. Moreover, the potential innovation capabilities in vaccine production are assumed as engines of biotechnology development which is among the emerging technologies that can support the technological development of a country. This review is based on analyses of scientific articles, literature, textbooks and reports by the international organization, as well as online databases with the subject of innovation in vaccine production, in order to identify current challenges in vaccine development and production. Not long ago, the most important challenges in this field were assumed as technical or budgetary issues. However nowadays, due to a global paradigm-shift in vaccine production which has changed from innovation aimed solely at the registration of new products toward promoting public health, other challenges in competition and commercialization have stepped in. The identified new challenges and bottlenecks could be used to form practical approaches in policy-making toward vaccine development and production. Furthermore, overcoming these challenges requires identifying the bottlenecks and proper orientation with the current world circumstances to draft a functional policy that could fulfill the national health system objectives. Here, following explaining these global challenges and approaches, the situation of vaccine industry in Iran will be briefly discussed.
    Keywords: Policy-making, Vaccine, Enablers, blockers, Innovation, Biotechnology
  • Kavehei B, Habibi M, Sari S, Asadi Karam MR Pages 14-18
    Introduction
    Proteus mirabilis is one of the common pathogens of urinary tract infections. Iron scavenger receptors from P. mirabilis are considered as important virulence factors of this strain and have the properties of an ideal vaccine candidate. In this study, the frequency of P. mirabilis iron receptor 1945 (PMI1945) was evaluated in the isolates and then its expression was conducted in pET28a-BL21.
    Methods
    Amplification of PMI1945 was performed by PCR using P. mirabilis isolates genomic DNA. Cloning of PMI1945 gene was done in pET28a-BL21 system. After transformation, the expression of the cloned gene was induced by IPTG. The expression of this protein was then evaluated by SDS-PAGE and Western blot techniques.
    Results
    The frequency of PMI1945 gene in the isolates was 76%. The cloning of PMI1945 gene into pET28a vector was confirmed by electrophoresis, PCR, enzyme digestion and sequencing. The sequencing of the cloned gene showed 100% identity with other sequences of PMI1945 gene in GenBank. SDS-PAGE and Western blot results showed that 77 kDa PMI1945 protein was successfully expressed in BL21 (DE3) host.
    Conclusion
    Cloning and expression of PMI1945 was done as the first step for evaluation of a novel vaccine candidate against UTIs caused by P. mirabilis.
    Keywords: Proteus mirabilis, Iron scavenger receptors, PMI1945, Cloning, Expression
  • Rashid S, Shahsavandi S*, Ebrahimi MM, Soleimani S Pages 19-22
    Introduction
    Live and inactivated vaccines are wildly used against Newcastle disease (ND) which is a highly contagious and acute viral infection of domestic and wild birds. A higher and prolonged immune response is required to improve the control of the disease. The aim of this study was to evaluate the potential of the conserved TIR domain of an immune regulatory protein TLR7 (i.e. TIR-TLR7) as a biological adjuvant in enhancing cell-mediated immunity in vaccinated chickens against the inactivated ND virus (NDV) V4 strain antigen.
    Methods
    NDV V4 strain was propagated in chicken embryonated SPF eggs, tittered and then inactivated by formalin. The amount of 10 μg of TIR-TLR7 was mixed with the NDV antigen before intramuscular administration. Fifty SPF chickens were divided in A-E groups (n=10), consisted of negative control, TIR-TLR7, inactivated NDV antigen, TIR-TLR7/inactivated NDV antigen in prime, and the same regimen in boost platform. The blood samples were collected at week intervals up to 6 weeks post-vaccination. Humoral response was measured by detection of specific NDV antibody titer using the HI test. The cell-mediated immunity was evaluated by measuring lymphocyte proliferation in splenocytes cell culture using MTT.
    Results
    All immunized chickens with TIR-TLR7/inactivated NDV antigen had significant (P < 0.05) cell-mediated and HI responses to NDV compared to the control groups. No statistically-significant difference was observed between the prime and boost trials.
    Conclusion
    The results indicated that the combination of TIR-TLR7 and inactivated NDV antigen gave a strong immune response at both the humoral and the cellular levels.
    Keywords: Newcastle disease, inactivated vaccine, TIR-TLR7, immune response
  • Sadeghi SA, Shahanaghi M, Aghasadeghi MR, Motevalli F, Amiran MR, Mohammadi Pargoo S, Hamidi, Fard M Pages 23-26
    Introduction
    Hepatitis E virus (HEV) is a non-enveloped, single-stranded positive-sense RNA virus. It is one of the most important causes of liver failures and the mortality rate arising from HEV is more common in pregnant women. HEV is an enterically-transmitted virus and its outbreak is more common in the developing and poor-hygiene countries while vaccination against it can prevent its prevalence. The ORF2 is an immunogenic capsid protein of HEV with 660 amino acids that is being used in vaccine designs against HEV infection. ORF2 has been studied in a vast range of vectors and hosts, such as pRSET-C, pMAL and pSG vectors, as well as Escherichia coli BL21 and vaccinia virus hosts. A DNA vaccine expressing ORF2 has also been studied which has induced specific humoral and cellular immune responses in mice. This study was aimed to clone and express ORF2 as an immunogen protein in a eukaryotic host system.
    Methods
    orf2 gene corresponding to 660 amino acids of ORF2 protein was subcloned from a pET21avector into pFastBac. The protein expression was achieved by transforming Sf9 insect cells with a pFastBac-orf2 construct. The over-expressed protein with ~72 kDa MW was assessed by SDS-PAGE.
    Results
    The cloning was confirmed by PCR and restriction digestions. The expression of ORF2 with expected MW in Sf9 cells was confirmed by SDS-PAGE.
    Conclusion
    ORF2 protein of HEV was successfully expressed in a baculovirus-based eukaryotic expression system as the first step for further studies on HEV vaccine designs, based on ORF2 protein.
    Keywords: Baculovirus, Hepatitis E virus, ORF2, Vaccine
  • Rabiei N, Ahmadi Badi S, Ettehad Marvasti F, Nejad Sattari T, Vaziri F, Siadat SD Pages 27-31
    Introduction
    Extracellular vesicles (EVs) are spherical structures, naturally secreted by Gram-negative and Gram-positive bacteria. EVs play a critical role in the modulation of immune responses, bioactive cargo delivery, and cell-cell communication. The conventional method of EVs preparation involves the use of detergent (ultracentrifugation method). For the first time, we used a polyethylene glycol (PEG)-based method in our study to isolate EVs from prokaryotic cells, namely Faecalibacterium prausnitzii A2-165. We then compared various features of this method with those of the ultracentrifugation method.
    Methods
    Extraction of EVs was performed via sequential deoxycholate ultracentrifugation and PEG-based methods. The physicochemical properties of the extracted EVs were compared via scanning electron microscopy (SEM), SDS-PAGE, and dynamic light scattering (DLS).
    Results
    The protein content of the extracted EVs was 1.6 and 0.5 mg/mL, based on the ultracentrifugation and PEG-based methods, respectively. According to the SDS-PAGE analysis, vesicle-associated proteins were located at 20-150 kDa. The SEM analysis showed that the extracted EVs had a diameter of 50-200 nm in both methods. The results of DLS analysis showed 4 populations of approximately 50-8000 nm in the ultracentrifugation method and approximately 100-2000 nm in the PEG-based method. The EVs extracted by the ultracentrifugation method showed higher negative charge densities in contrast to EVs extracted by the PEG-based method.
    Conclusion
    Our result showed that PEG-based extraction is a fast, simple, and cost-effective method and EVs purity was within the acceptable range. Further studies are needed to confirm the safety and the efficacy of EVs in clinical practices, especially as vaccine delivery vehicles.
    Keywords: Faecalibacterium prausnitzii, isolation methods, outer membrane vesicles, vaccine vehicle
  • Parsamanesh M Pages 32-40
    Introduction
    Infectious diseases threaten the public health; hence understanding their propagation mechanisms may help to control them. Mathematical models are tools that can help the scientists to understand the pathogens’ propagations and can provide strategies for their control in future.
    Methods
    Using mathematical theorems and MATLAB software, a continuous-time model known as susceptible-infected-susceptible (SIS) for transmission of infection in a population was described and the effects of a vaccination program based on this framework was investigated.
    Results
    It was shown that the model had two equilibria: the infection-free equilibrium and the infected equilibrium. A specific threshold in terms of model parameters was obtained and then the existence of the equilibria and asymptotic stability of the system were stated with respect to this threshold. The theoretical results were also verified numerically by providing several simulations.
    Conclusion
    The results indicated the stability of this model which emphasized that parameters such as restricting the immigration, reducing harmful contacts between the susceptible and the infected individuals, increasing awareness level of people, and most-importantly vaccination will reduce the basic reproduction number and help to control the disease. Moreover, a relation to calculate the minimum doses for vaccinating of the new-comers and the susceptible individuals, was obtained.
    Keywords: Dynamical system, Epidemilogical model, SIS model, Stability, Vaccine