V. Nikbin, M. Keramati, M. Noofeli, N. Bolourchi, Shams Nosrati, F. Shahcheraghi
Introduction: Pathogen adaptation is considered as one of the important reasons for the emergence of pertussis (whooping cough). Antigenic divergence between vaccine strains and clinical isolates of Bordetella pertussis has been occurred over the years. It is suggested that the predominant genomic profile of B. pertussis has an enough capacity to spread among the population. The aim of this study was to characterize a predominant B. pertussis strain isolated from Iranian patients during 2008-2015 period. Methods: Based on the epidemiologic results of B. pertussis circulating strains in Iran, a strain named BPIP91 with predominant genomic and virulence pattern was selected from Biobank of Pasteur Institute of Iran. The antibiotic susceptibility testing was done and the growth rate of this strain was analyzed. The lethal (LD50) and safety dose of infection of BPIP91 was also determined via mice intranasal infection. Results: Our results showed that BPIP91 was susceptible to erythromycin, azithromycin, clarithromycin, chloramphenicol, trimethoprim-sulfamethoxazole and rifampin antibiotics. The growth rate of BPIP91 was almost two-fold lower than the vaccine strain. In addition, the LD50 and infectious dose of BPIP91 strain were about 2 × 10 10 and 4 × 10 6 colony forming units, respectively. Conclusion: In this study we obtained the growth curve, LD50 and intranasal infectious dose of a circulating strain with predominant genomic pattern in Iran. However, further examinations including determination of immunogenicity of this native strain in animal model is needed in order to evaluate its use as a vaccine strain candidate.
{"title":"Characterization of a predominant Bordetella pertussis strain isolated from Iranian patients","authors":"V. Nikbin, M. Keramati, M. Noofeli, N. Bolourchi, Shams Nosrati, F. Shahcheraghi","doi":"10.29252/vacres.5.2.52","DOIUrl":"https://doi.org/10.29252/vacres.5.2.52","url":null,"abstract":"Introduction: Pathogen adaptation is considered as one of the important reasons for the emergence of pertussis (whooping cough). Antigenic divergence between vaccine strains and clinical isolates of Bordetella pertussis has been occurred over the years. It is suggested that the predominant genomic profile of B. pertussis has an enough capacity to spread among the population. The aim of this study was to characterize a predominant B. pertussis strain isolated from Iranian patients during 2008-2015 period. Methods: Based on the epidemiologic results of B. pertussis circulating strains in Iran, a strain named BPIP91 with predominant genomic and virulence pattern was selected from Biobank of Pasteur Institute of Iran. The antibiotic susceptibility testing was done and the growth rate of this strain was analyzed. The lethal (LD50) and safety dose of infection of BPIP91 was also determined via mice intranasal infection. Results: Our results showed that BPIP91 was susceptible to erythromycin, azithromycin, clarithromycin, chloramphenicol, trimethoprim-sulfamethoxazole and rifampin antibiotics. The growth rate of BPIP91 was almost two-fold lower than the vaccine strain. In addition, the LD50 and infectious dose of BPIP91 strain were about 2 × 10 10 and 4 × 10 6 colony forming units, respectively. Conclusion: In this study we obtained the growth curve, LD50 and intranasal infectious dose of a circulating strain with predominant genomic pattern in Iran. However, further examinations including determination of immunogenicity of this native strain in animal model is needed in order to evaluate its use as a vaccine strain candidate.","PeriodicalId":52727,"journal":{"name":"Vaccine Research","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42325834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Sedaghat, S. Siadat, E. M. Ardakani, M. Keramati, F. Vaziri, F. Shahcheraghi
Introduction: Serum bactericidal assay is the gold standard index of protection against Vibrio cholerae. The outer membrane vesicles (OMVs) which are released during the bacterial growth have intrinsic immune stimulatory properties, based on their nature and composition. In this study, the induction of serum bactericidal activities in immunized BALB/c mice was determined using different vaccine regimens, using V. cholerae O1 (El Tor biotype) OMVs. Methods: A single clone of V. cholerae O1 (El Tor biotype) isolated during the 2005 outbreak in Iran, was used. A detergent-centrifugation procedure was used for OMVs production. Various vaccination regimens were inoculated into female mice via an oral route. The vaccine formulas included V. cholerae OMVs, killed whole cells of V. cholerae (WC), combination of WC-OMV and licensed cholera vaccine (Dukoral).The serum vibriocidal activity of mice sera was determined by measuring the complement-mediated lysis. Results: Electron microscopy of the purified OMVs from the isolated V. cholerae revealed the spherical-shaped vesicles of the size range 20-300 nm. In vitro reactivity of mice sera bactericidal capability against regimens of vaccination showed a significant immune response of antibody titers in comparison with negative control groups. Also, there was a significant increase in serum bactericidal titer of WC-OMV obtained from wild-type V. cholerae which had a satisfactory reactivity as Dukoral cholera vaccine. Conclusion: The results indicated that the combination of WC-OMV from the local strain is able to induce a high level of bactericidal antibody responses and it can be useful in optimization of the vaccine formula.
{"title":"Determination of bactericidal activity of serum against Vibrio cholerae outer membrane vesicles in BALB/c mice","authors":"M. Sedaghat, S. Siadat, E. M. Ardakani, M. Keramati, F. Vaziri, F. Shahcheraghi","doi":"10.29252/vacres.5.2.47","DOIUrl":"https://doi.org/10.29252/vacres.5.2.47","url":null,"abstract":"Introduction: Serum bactericidal assay is the gold standard index of protection against Vibrio cholerae. The outer membrane vesicles (OMVs) which are released during the bacterial growth have intrinsic immune stimulatory properties, based on their nature and composition. In this study, the induction of serum bactericidal activities in immunized BALB/c mice was determined using different vaccine regimens, using V. cholerae O1 (El Tor biotype) OMVs. Methods: A single clone of V. cholerae O1 (El Tor biotype) isolated during the 2005 outbreak in Iran, was used. A detergent-centrifugation procedure was used for OMVs production. Various vaccination regimens were inoculated into female mice via an oral route. The vaccine formulas included V. cholerae OMVs, killed whole cells of V. cholerae (WC), combination of WC-OMV and licensed cholera vaccine (Dukoral).The serum vibriocidal activity of mice sera was determined by measuring the complement-mediated lysis. Results: Electron microscopy of the purified OMVs from the isolated V. cholerae revealed the spherical-shaped vesicles of the size range 20-300 nm. In vitro reactivity of mice sera bactericidal capability against regimens of vaccination showed a significant immune response of antibody titers in comparison with negative control groups. Also, there was a significant increase in serum bactericidal titer of WC-OMV obtained from wild-type V. cholerae which had a satisfactory reactivity as Dukoral cholera vaccine. Conclusion: The results indicated that the combination of WC-OMV from the local strain is able to induce a high level of bactericidal antibody responses and it can be useful in optimization of the vaccine formula.","PeriodicalId":52727,"journal":{"name":"Vaccine Research","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46457430","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Diphtheria is a preventable infection caused by Corynebacterium diphtheriae . This disease can cause severe respiratory tract problems in affected children. At present, this disease is still encountered in poor developing countries with poor sanitation backgrounds. In 2012, a major outbreak of diphtheria occurred in Indochina. The disease was also diagnosed in remote areas of Laos and Thailand [1 – 3]. Another diphtheria outbreak occurred in South Africa in 2015 [4]. Among the great considerations for each diphtheria outbreak are usually the availability, quality and the coverage of the vaccine. Hence, the data from epidemiology surveillance and records in each setting are useful for the assessment of diphteria situation in each area. Here, we performed a reappraisal on seroepidemiology data from 2012 diphtheria outbreak in Laos and tried to predict the rate of children prone to diphtheria infection in that country. We used a mathematical model study using the locally available data on the diphtheria outbreak in Laos. The protocol was the same as the one which had been used in a previous report by Joob and Wiwanitkit [5]. The available published data from a previous seroepidemiology study in Laos was used as the primary data [5]. Briefly, the mathematical model was based on the standard joint probability mathematic principle. To predict the rate of diphtheria infection among children in that area, the following formula was used: “1 – (diphtheria vaccine coverage rate × diphtheria vaccine efficacy rate)” and the final calculated prone rate was presented as a percentage. Based on the available data [3], the diphtheria vaccine coverage rate and diphtheria vaccine efficacy rate were equal to 59.8 % and 83
{"title":"Prediction of the rate of children prone to diphtheria infection in a Laos remote area: A reappraisal on seroepidemiology data during a major diphtheria outbreak in 2012","authors":"S. Wiwanitkit, Wiwanitkit","doi":"10.29252/vacres.5.2.42","DOIUrl":"https://doi.org/10.29252/vacres.5.2.42","url":null,"abstract":"Diphtheria is a preventable infection caused by Corynebacterium diphtheriae . This disease can cause severe respiratory tract problems in affected children. At present, this disease is still encountered in poor developing countries with poor sanitation backgrounds. In 2012, a major outbreak of diphtheria occurred in Indochina. The disease was also diagnosed in remote areas of Laos and Thailand [1 – 3]. Another diphtheria outbreak occurred in South Africa in 2015 [4]. Among the great considerations for each diphtheria outbreak are usually the availability, quality and the coverage of the vaccine. Hence, the data from epidemiology surveillance and records in each setting are useful for the assessment of diphteria situation in each area. Here, we performed a reappraisal on seroepidemiology data from 2012 diphtheria outbreak in Laos and tried to predict the rate of children prone to diphtheria infection in that country. We used a mathematical model study using the locally available data on the diphtheria outbreak in Laos. The protocol was the same as the one which had been used in a previous report by Joob and Wiwanitkit [5]. The available published data from a previous seroepidemiology study in Laos was used as the primary data [5]. Briefly, the mathematical model was based on the standard joint probability mathematic principle. To predict the rate of diphtheria infection among children in that area, the following formula was used: “1 – (diphtheria vaccine coverage rate × diphtheria vaccine efficacy rate)” and the final calculated prone rate was presented as a percentage. Based on the available data [3], the diphtheria vaccine coverage rate and diphtheria vaccine efficacy rate were equal to 59.8 % and 83","PeriodicalId":52727,"journal":{"name":"Vaccine Research","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42535346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Sekhavati, S. Siadat, M. Noofeli, A. M. Mobarez
Introduction: In spite of high vaccination coverage, whooping cough (pertussis) is still a worldwide health problem. The main reason for pertussis outbreak is waning immunity of safer acellular vaccines which have replaced the more reactogenic cellular vaccines. A new generation of pertussis vaccines that is potent and safe is desperately needed to control the disease. Previous studies have indicated that outer membrane vesicles (OMVs) obtained from Bordetella pertussis have desirable characteristics which make them a good candidate for application as pertussis vaccine. They contain surface immunogens in a native structure, are self-adjuvant and are easily uptaken by the antigen presenting cells. Methods: B. pertussis Tohama strain was cultured at 35°C in Stainer-Scholte broth. The OMVs were isolated by a new sequential ultracentrifugation method. The extracted OMVs were characterized by electron microscopy, SDSPAGE and ELISA assays. Results: The existence of pertussis toxin, filamentous haemagglutinin and a 69-kDa antigen in B. pertussis OMVs was verified using an ELISA assay. Electron microscopy showed the size of these OMV’s at 40200 nm. The ELISA results indicated that the OMVs extracted using this protocol contain major immunogens. Conclusion: We report for the first time a simple protocol for the efficient extraction of B. pertussis OMVs. This protocol can be used in the process of making new generations of B. pertussis vaccines.
{"title":"A streamlined method for the extraction of outer membrane vesicles (OMVs) from Bordetella pertussis","authors":"M. Sekhavati, S. Siadat, M. Noofeli, A. M. Mobarez","doi":"10.29252/vacres.5.2.43","DOIUrl":"https://doi.org/10.29252/vacres.5.2.43","url":null,"abstract":"Introduction: In spite of high vaccination coverage, whooping cough (pertussis) is still a worldwide health problem. The main reason for pertussis outbreak is waning immunity of safer acellular vaccines which have replaced the more reactogenic cellular vaccines. A new generation of pertussis vaccines that is potent and safe is desperately needed to control the disease. Previous studies have indicated that outer membrane vesicles (OMVs) obtained from Bordetella pertussis have desirable characteristics which make them a good candidate for application as pertussis vaccine. They contain surface immunogens in a native structure, are self-adjuvant and are easily uptaken by the antigen presenting cells. Methods: B. pertussis Tohama strain was cultured at 35°C in Stainer-Scholte broth. The OMVs were isolated by a new sequential ultracentrifugation method. The extracted OMVs were characterized by electron microscopy, SDSPAGE and ELISA assays. Results: The existence of pertussis toxin, filamentous haemagglutinin and a 69-kDa antigen in B. pertussis OMVs was verified using an ELISA assay. Electron microscopy showed the size of these OMV’s at 40200 nm. The ELISA results indicated that the OMVs extracted using this protocol contain major immunogens. Conclusion: We report for the first time a simple protocol for the efficient extraction of B. pertussis OMVs. This protocol can be used in the process of making new generations of B. pertussis vaccines.","PeriodicalId":52727,"journal":{"name":"Vaccine Research","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47378824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rotaviruses are non-enveloped viruses of the Reoviridae family which are worldwide leading cause of acute gastroenteritis (AGE) in under 5-year-old children [1]. Infection by rotaviruses is one of the major causes of childhood diarrhea with an associated high mortality rate (440,000 deaths/year) and is responsible for 25 million medical visits and 2 million hospitalizations every year, especially during the cold season [2-3]. The prevalence of rotavirus infections in Iran has been estimated as 30% -50% while the mean prevalence is reported to be 39.9% [4]. According to WHO report, in Iran 42% of gastroenteritis are caused by rotaviruses which is estimated to have inflicted approximately 2000 and 270 deaths in 2008 and 2013, respectively [5]. This pattern indicated that the rate of rotavirus-caused diarrhea for Iranian children is similar to the rate in Eastern Mediterranean region. The prevalence of rotavirus infection is varied in different regions of Iran. For instance, this rate is 6.3% for Birjand region (South Khorasan province) and 79.2% in Tehran [6]. It is very important to determine the circulating rotavirus strains for studies related to its classification, molecular epidemiology and vaccines. Based on the glycoprotein VP7(G) and the proteasecleaved protein VP4(P) types, rotaviruses have been classified into at least 27 G and 35 P genotypes [7]. Overall in Iran, G1P[8], G2P[4] and G4P[8] are accounted for more than 60% of all detected rotavirus strains while G1P[8] alone representing over 50% of all rotavirus infections. However, G1 genotype appears to decrease with emergence of G8P[NT], G9P[8], G9P[6], G12P[8] and G12P[6] as well as other novel genotypes. Emerging and uncommon genotypes such as G9P[8], G3P[8], G1P[4], G3P[9], G12P[8], G1P[10] and G8P[NT] have also been found in Iran which suggest a diversity of rotavirus genotypes in the infected Iranian children [8, 9]. It is well recognized that the impacts of rotavirus vaccines on severe rotavirus and all-cause diarrhea have been dramatic in all countries that have introduced the vaccines. The two multinational vaccines prequalified in 2006, namely ROTARIX and RotaTeq, are included in the national immunization programs or in phased subnational introductions in 95 countries across the globe [10]. HRV and HBRV have shown similar efficacy in the clinical trials and exhibit similar safety profiles in terms of risk of intussusception [11]. ROTAVAC (Bharat Biotech) contains naturally attenuated monovalent G9P [11] rotavirus and achieved WHO prequalification in January 2018, enabling the global use of
{"title":"Rotavirus infection in Iran and current vaccines against it","authors":"S. Mousavi-Nasab, H. Kaghazian","doi":"10.29252/vacres.5.2.41","DOIUrl":"https://doi.org/10.29252/vacres.5.2.41","url":null,"abstract":"Rotaviruses are non-enveloped viruses of the Reoviridae family which are worldwide leading cause of acute gastroenteritis (AGE) in under 5-year-old children [1]. Infection by rotaviruses is one of the major causes of childhood diarrhea with an associated high mortality rate (440,000 deaths/year) and is responsible for 25 million medical visits and 2 million hospitalizations every year, especially during the cold season [2-3]. The prevalence of rotavirus infections in Iran has been estimated as 30% -50% while the mean prevalence is reported to be 39.9% [4]. According to WHO report, in Iran 42% of gastroenteritis are caused by rotaviruses which is estimated to have inflicted approximately 2000 and 270 deaths in 2008 and 2013, respectively [5]. This pattern indicated that the rate of rotavirus-caused diarrhea for Iranian children is similar to the rate in Eastern Mediterranean region. The prevalence of rotavirus infection is varied in different regions of Iran. For instance, this rate is 6.3% for Birjand region (South Khorasan province) and 79.2% in Tehran [6]. It is very important to determine the circulating rotavirus strains for studies related to its classification, molecular epidemiology and vaccines. Based on the glycoprotein VP7(G) and the proteasecleaved protein VP4(P) types, rotaviruses have been classified into at least 27 G and 35 P genotypes [7]. Overall in Iran, G1P[8], G2P[4] and G4P[8] are accounted for more than 60% of all detected rotavirus strains while G1P[8] alone representing over 50% of all rotavirus infections. However, G1 genotype appears to decrease with emergence of G8P[NT], G9P[8], G9P[6], G12P[8] and G12P[6] as well as other novel genotypes. Emerging and uncommon genotypes such as G9P[8], G3P[8], G1P[4], G3P[9], G12P[8], G1P[10] and G8P[NT] have also been found in Iran which suggest a diversity of rotavirus genotypes in the infected Iranian children [8, 9]. It is well recognized that the impacts of rotavirus vaccines on severe rotavirus and all-cause diarrhea have been dramatic in all countries that have introduced the vaccines. The two multinational vaccines prequalified in 2006, namely ROTARIX and RotaTeq, are included in the national immunization programs or in phased subnational introductions in 95 countries across the globe [10]. HRV and HBRV have shown similar efficacy in the clinical trials and exhibit similar safety profiles in terms of risk of intussusception [11]. ROTAVAC (Bharat Biotech) contains naturally attenuated monovalent G9P [11] rotavirus and achieved WHO prequalification in January 2018, enabling the global use of","PeriodicalId":52727,"journal":{"name":"Vaccine Research","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48518197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. E. Vargoorani, M. Modarressi, E. Motevaseli, F. Vaziri, S. Siadat
Introduction The secretion of extracellular vesicles (EVs) has been neglected in Gram-positive bacteria due to the absence of an outer membrane and the difficulties of proper visualization. Here we aimed to prove that lactobacillus casei can secrete extracellular vesicles. Methods : EVs were extracted from Lactobacillus casei , cultured in De Man, Rogosa and Sharpe broth, using a polyethylene glycol (PEG) solution. The characteristics of the EVs were analyzed by electron microscopy, Dynamic Light Scattering (DLS) and SDS-PAGE. Results: The electron microscopy showed rounded vesicles with average diameter of 300 nm. The protein content of this nanostructure was 2.5 mg/ml with a protein pattern within the range of 10-200 kDa. DLS result showed populations of approximately 300 nm while the extracted EVs had a negative zeta potential. Conclusion: A new method of producing functional molecules from probiotic bacteria was presented. Our results indicated EVs purity with acceptable conformation. Further investigations are necessary to elucidate the efficacy, practicality and mechanism of action of such EVs in clinical practices, especially for development of bio-compounds and vaccine delivery vehicles.
{"title":"A polyethylene glycol-based method for extraction of extracellular vesicles from Lactobacillus casei as vaccine delivery vehicle","authors":"M. E. Vargoorani, M. Modarressi, E. Motevaseli, F. Vaziri, S. Siadat","doi":"10.29252/vacres.5.2.57","DOIUrl":"https://doi.org/10.29252/vacres.5.2.57","url":null,"abstract":"Introduction The secretion of extracellular vesicles (EVs) has been neglected in Gram-positive bacteria due to the absence of an outer membrane and the difficulties of proper visualization. Here we aimed to prove that lactobacillus casei can secrete extracellular vesicles. Methods : EVs were extracted from Lactobacillus casei , cultured in De Man, Rogosa and Sharpe broth, using a polyethylene glycol (PEG) solution. The characteristics of the EVs were analyzed by electron microscopy, Dynamic Light Scattering (DLS) and SDS-PAGE. Results: The electron microscopy showed rounded vesicles with average diameter of 300 nm. The protein content of this nanostructure was 2.5 mg/ml with a protein pattern within the range of 10-200 kDa. DLS result showed populations of approximately 300 nm while the extracted EVs had a negative zeta potential. Conclusion: A new method of producing functional molecules from probiotic bacteria was presented. Our results indicated EVs purity with acceptable conformation. Further investigations are necessary to elucidate the efficacy, practicality and mechanism of action of such EVs in clinical practices, especially for development of bio-compounds and vaccine delivery vehicles.","PeriodicalId":52727,"journal":{"name":"Vaccine Research","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48847086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Najafi-Dastanaei, S. Ajdary, Khaze, Haiedeh Darabi, M. Alimohammadian
Introduction: Leishmania infantum is the causative agent of visceral leishmaniasis (VL). Cell-mediated immunity (CMI) is required to control leishmaniases. Therefore, simple tests that can evaluate the cellular immunity of the target populations can help to understand the immune status of the human subjects, their immunity to the re-infection and the evaluation of the effectiveness of the potential vaccines. Here, we compared antigens based on single clones of L. infantum promastigotes and axenic amastigotes by in vitro and in vivo tests. Methods: Using serial dilutions, L. infantum promastigotes were selected as single clones (PSC) or were grown under axenic conditions with succinate-tris to prepare amastigote-like single clones (ASC). Antigens prepared from PSC and ASC were then compared with typical Leishmania major and L. infantum amastigotes by SDS-PAGE, Western-blotting and proliferation tests as well as an in vivo delayed-type hypersensitivity test on guinea pigs. Results Both PSC and ASC exhibited a distinctive ~50-kDa band could be detected by Western-blotting. The proliferation tests results indicated that both PSC and ASC could cause higher lymphocyte proliferation compared to typical L. infantum and L. major promastigotes; however the differences were not significant. Moreover, both PSC and ASC had an ability to induce comparable DTH and hence CMI. Conclusion: Similar proliferation or delayed-type hypersensitivity could be caused with antigens based on PSC, ASC or the typical promastigotes and any of these reagents could potentially be used for in vivo detection of CMI in VL epidemiological or vaccine studies.
{"title":"Comparison of cell-mediated immunity due to Leishmania infantum promastigotes and axenic amastigotes","authors":"A. Najafi-Dastanaei, S. Ajdary, Khaze, Haiedeh Darabi, M. Alimohammadian","doi":"10.29252/vacres.5.2.63","DOIUrl":"https://doi.org/10.29252/vacres.5.2.63","url":null,"abstract":"Introduction: Leishmania infantum is the causative agent of visceral leishmaniasis (VL). Cell-mediated immunity (CMI) is required to control leishmaniases. Therefore, simple tests that can evaluate the cellular immunity of the target populations can help to understand the immune status of the human subjects, their immunity to the re-infection and the evaluation of the effectiveness of the potential vaccines. Here, we compared antigens based on single clones of L. infantum promastigotes and axenic amastigotes by in vitro and in vivo tests. Methods: Using serial dilutions, L. infantum promastigotes were selected as single clones (PSC) or were grown under axenic conditions with succinate-tris to prepare amastigote-like single clones (ASC). Antigens prepared from PSC and ASC were then compared with typical Leishmania major and L. infantum amastigotes by SDS-PAGE, Western-blotting and proliferation tests as well as an in vivo delayed-type hypersensitivity test on guinea pigs. Results Both PSC and ASC exhibited a distinctive ~50-kDa band could be detected by Western-blotting. The proliferation tests results indicated that both PSC and ASC could cause higher lymphocyte proliferation compared to typical L. infantum and L. major promastigotes; however the differences were not significant. Moreover, both PSC and ASC had an ability to induce comparable DTH and hence CMI. Conclusion: Similar proliferation or delayed-type hypersensitivity could be caused with antigens based on PSC, ASC or the typical promastigotes and any of these reagents could potentially be used for in vivo detection of CMI in VL epidemiological or vaccine studies.","PeriodicalId":52727,"journal":{"name":"Vaccine Research","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48671561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Marandi, Shadab Tabatabaeian, P. Jafari, M. Azarnoosh
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.
{"title":"Challenge-based approaches for policy-making in vaccine development and production","authors":"Marandi, Shadab Tabatabaeian, P. Jafari, M. Azarnoosh","doi":"10.29252/VACRES.5.1.7","DOIUrl":"https://doi.org/10.29252/VACRES.5.1.7","url":null,"abstract":"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.","PeriodicalId":52727,"journal":{"name":"Vaccine Research","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48386615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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.
{"title":"The role of vaccination in controlling the outbreak of infectious diseases: a mathematical approach","authors":"Mahmood Parsamanesh","doi":"10.29252/vacres.5.1.32","DOIUrl":"https://doi.org/10.29252/vacres.5.1.32","url":null,"abstract":"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.","PeriodicalId":52727,"journal":{"name":"Vaccine Research","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42446514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Cloning and expression of PMI1945 involved in iron acquisition as a promising vaccine candidate against Proteus mirabilis","authors":"B. Kavehei, M. Habibi, S. Sari, Asadi Karam","doi":"10.29252/VACRES.5.1.14","DOIUrl":"https://doi.org/10.29252/VACRES.5.1.14","url":null,"abstract":"","PeriodicalId":52727,"journal":{"name":"Vaccine Research","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41961343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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