فهرست مطالب

  • Volume:7 Issue: 18, 2020
  • تاریخ انتشار: 1399/06/26
  • تعداد عناوین: 7
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  • Frédéric Vangroenweghe*, Olivier Thas Pages 1-9
    Introduction

    Post-weaning diarrhea (PWD) in pigs is a worldwide economically important disease, which is frequently controlled using antibiotics. However, emergence of antimicrobial resistance in Escherichia coli strains urges the need for alternative control measures, such as adapted feeding strategies, pre- and probiotics, organic acids, MCFAs or immunization.

    Methods

    Different  alternative control strategies such as active immunization of piglets against PWD with an E. coli F4 vaccine (Coliprotec® F4; Elanco) combined with high energy and protein diets, addition of nutraceuticals (medium chain fatty acids (MCFAs), organic acids and additional fibers) or supplementation of ZnO were evaluated for their efficacy against PWD due to F4 enterotoxigenic E. coli (F4-ETEC) under field conditions.

    Results

    ZnO-supplemented piglets had a lower overall end weight and lower average daily weight gain, as compared to E. coli vaccinated piglets. The E. coli vaccinated group with normal energy and protein diet had the lowest clinical scores, whereas piglets fed a ZnO-supplemented diet had intermediate fecal clinical scores. All E. coli vaccinated groups had a low number of antibiotic treatments. In the nutraceutical group, clinical scores were much higher, indicating more severe clinical diarrhea, which needed additional antibiotic intervention.

    Conclusions

    The present study demonstrated the efficacy of an oral live non-pathogenic E. coli F4 vaccine for active immunization of piglets against PWD due to F4-ETEC under field conditions. Different feeding strategies had no significant effect on the clinical outcome and performance parameters of E. coli vaccinated piglets.

    Keywords: F4-ETEC, PWD, E. coli F4 vaccine, performance, high energy, protein diets
  • Avnish Kumar*, Bhuvnesh Prasad Sharma Pages 10-16
    Introduction

    Coronavirus family member SARS- CoV-2 is a current worldwide threat. It enters into the epithelium membrane of respiratory tract with the help of its antigenic spike proteins and cause Coronavirus disease 2019 (COVID -19).

    Methods

    Considering SARS- CoV-2 a potent vaccine or diagnostic candidate, a bioinformatical study was done to determine its structure homology modeling, physiological properties and structure validation with presence of antigenic sites.

    Results

    The surface glycoprotein of SARS-CoV-2 was found to be a stable protein with stereochemically good structure. It also contains 65 antigenic sites.

    Conclusion

    The present study suggests further wet-lab research to develop a vaccine or diagnostic kit using this promising surface glycoprotein.

    Keywords: COVID-19, 6VSB, corona vaccine, Spike protein, Glycoprotein
  • Nassir Rashnaei, Seyed Davar Siadat, Abbas Akhavan Sepahi, Mohsen Mirzaee, Golnaz Bahramali *, Abolfazl Arab Joshaghani* Pages 17-24
    Introduction

    Silver nanoparticles are particles of silver with a size of 1 to 100 nm. These agents have various applications and particularly have received much attention for their antibacterial activity and their use in vaccine production. Among the various methods of synthesizing nanoparticles, using plants due to their high reducing capabilities and also their eco-friendliness is of interest.

    Methods

    Silver nanoparticles (AgNPs) were synthesized using plant anise (Pimpinella anisum L.) and validated using UV-spectrophotometer, transmission electron microscopy and Fourier transform infrared spectroscopy. The produced AgNPs were used against Escherichia coli, Salmonella typhimurium, Staphylococcus aureus and Enterococcus faecalis to examine their antibacterial activities via agar well diffusion, disk diffusion and minimum inhibitory concentration methods. Furthermore, AgNPs were used in combination with three antibiotic disks, namely, Ceftriaxone, Tetracycline and Gentamicin to seek any cooperative effect.

    Results

    Antibacterial effects due to the synthesized AgNPs were observed toward E. coli, S. aureus, S. typhimurium in this order; however, E. faecalis showed the highest resistance to the synthesized AgNPs.

    Conclusion

    AgNPs synthesized using anise had similar antibacterial effects as conventional antibiotics; however with potentially less side effects.

    Keywords: Anise, AgNPs biosynthesis, Antibacterial activity, adjuvanticity
  • Kenneth Lundstrom* Pages 25-37

    In addition to conventional vaccine development for infectious diseases, nucleic acid-based vaccine approaches have recently been presented as serious alternatives to previously used strategies based on live attenuated virus particles and subunit vaccines. Particularly, RNA-based vaccines have proven attractive. In this context, immunization with messenger RNA (mRNA) has provided strong immune responses and protection against challenges with lethal doses of pathogenic viruses in vaccinated animals. Alternatively, the efficient RNA replication mechanism provided by self-amplifying RNA (saRNA) viruses has been utilized. Enhanced immune responses with reduced doses required for immunization has been obtained in comparison to conventional mRNA administration. The rapid spread and destruction caused by the COVID-19 pandemic has substantially accelerated the demand for the development of robust and efficient vaccines against SARS-CoV-2. Both mRNA- and saRNA-based COVID-19 vaccine candidates are currently in human clinical trials.

    Keywords: RNA vectors, RNA replicons, RNA vaccines, immune responses, protection against pathogens, coronaviruses, COVID-19
  • Parent’s Knowledge on Rotavirus Diarrhea and Vaccine in Indonesia
    Arie Dwi Pratiwi, Dwi Endarti*, Tri Murti Andayani, Susi Ari Kristina Pages 38-43
    Introduction

    Parent’s knowledge on rotavirus diarrhea and vaccine might influence the decision to vaccinate a child. The purpose of this study was to examine knowledge level and to determine the factors that influence parents’ knowledge on rotavirus diarrhea and vaccine.

    Methods

    The study applied an observational study design with a multi-center cross-sectional approach. The research instrument used a questionnaire to determine the sociodemographic variables and knowledge of respondents.

    Results

    Data were collected from a survey of 500 parents in 5 provinces including Province of Central Kalimantan, Lampung, Central Sulawesi, West Java, and Yogyakarta in Indonesia using convenience sampling technique. Parents’ knowledge in this study was quite good with the average score of 78.2 ± 16.81. However, out of 500 respondents, only 158 (31.6%) parents knew that the rotavirus vaccine was not included in Indonesiachr('39')s national health insurance program. There was a significant difference in the average of knowledge between the characteristics groups of age, education, monthly expenditure and experience of hearing diarrhea and rotavirus vaccine, vaccinating and source of disease information and vaccine (p <0.05).

    Conclusion

    This study suggests the need of health promotion related to rotavirus diarrhea and vaccine in order to achieve equitable distribution of information and increase public knowledge to support future immunization programs.

    Keywords: Health literacy, Rotavirus diarrhea, Rotavirus vaccinepathogens, coronaviruses, COVID-19
  • * Fatemeh Motevalli, Mohammad Reza Amiran, Mazyar Etemadzadeh, Golnaz Bahramali, Soroush Sardari, Seyede Zahra Moravej, Pooneh Rahimi, Abolfazl Fateh, Seyed Alireza Seyed Siamdoust, Mohammad Ali Zaheri Birgani, Mojtaba Hamidi-Fard* Pages 44-49
    Introduction

    Hepatitis E virus (HEV) causes emerging diseases in poor regions of the world. The ORF2 is the only protein encoded by the virus to make the viral capsid. The aggregation of proteins into inclusion bodies (IBs) while expressing ORF2 is a major challenge in bioengineering.

    Methods

    The ORF2 conserved sequence was expressed in Escherichia coli BL21 and assessed by a modified SDS-PAGE containing a weak denaturing environment to solubilize the recombinant ORF2 protein and Western blotting. The protein of interest was evaluated by secondary structure prediction using SOPMA, homology modeling by I-TASSER and Circular Dichroism analyses. The function of the recombinant protein was investigated by an in-house ELISA using serum specimens of HEV infected patients.

    Results

    The solubilized form of ORF2 protein was successfully expressed in E. coli BL21 and was confirmed by SDS-PAGE and Western blotting. Secondary structure prediction, homology modeling and CD analysis of the protein of interest demonstrated that the native structure of ORF2 was almost intact. The specific anti-HEV antibody was detected using this recombinant protein and an in-house ELISA test.

    Conclusion

    We achieved new combinations of chemical agents, consisted of low concentrations of urea and detergents to overcome the aggregation of ORF2 protein in IBs inside E. coli BL21.

    Keywords: Hepatitis E virus, ORF2, Inclusion bodies, Protein solubilization
  • Patricia Méndez-Samperio* Pages 50-53

    Helminthiasis is a neglected public health challenge worldwide. The relevance of the important role of group 2 innate lymphoid cells (ILC2s) in the protection induced by    type 2 immune responses against helminth infections has recently regained attention. The parasitic helminth infections remain as a major public health concern worldwide, particularly in tropical countries in several areas of Africa, Asia, and South America. It has been demonstrated in the experimental mouse models that ILC2s induce significant secretion of type 2 cytokines and develop protective immunity against parasitic helminths infections. However, the effects of helminth-induced immunity mediated by ILC2s have not yet been clearly defined. This review discusses the current status of the researches related to the evidence of ILC2s to improve the protective immunity in parasitic helminth infections and how these cells promote parasitic helminth expulsion.

    Keywords: Helminth infection, Innate lymphoid cells, Th2 immune responses