Microbial compositional changes in broiler chicken cecal contents from birds challenged with different Salmonella vaccine candidate strains.

PubMed

Park, Si Hong; Kim, Sun Ae; Rubinelli, Peter M; Roto, Stephanie M; Ricke, Steven C

2017-05-31

Previously, we constructed and characterized the vaccine efficacy of Salmonella Typhimurium mutant strains in poultry with either inducible mviN expression (P BAD -mviN) or methionine auxotrophy (ΔΔmetRmetD). The aim of the present study was to assess potential impact of these Salmonella vaccine strains on the cecal microbiota using a next generation sequencing (NGS). The cecal microbial community obtained from unvaccinated (group 1) and vaccinated chickens (group 2, vaccinated with P BAD -mviN; group 3, vaccinated with wild type; group 4, vaccinated with ΔΔmetRmetD) were subjected to microbiome sequencing analysis with an Illumina MiSeq platform. The NGS microbiome analysis of chicken ceca revealed considerable changes in microbial composition in the presence of the different vaccine strains and exhibited detectable patterns of distinctive clustering among the respective groups (the R value of unweighted PCoA plot was 0.68). The present study indicates that different S. Typhimurium vaccine strains can differentially influence the microbiota of the ceca in terms of presence but not in the relative abundance of microbiota. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Genetic recombination in vaccine poliovirus: comparative study in strains excreted in course of vaccination by oral poliovirus vaccine and circulating strains].

PubMed

Haddad-Boubaker, S; Ould-Mohamed-Abdallah, M V; Ben-Yahia, A; Triki, H

2010-12-01

Recombination is one of the major mechanisms of evolution in poliovirus. In this work, recombination was assessed in children during vaccination with OPV and among circulating vaccine strains isolated in Tunisia during the last 15 years in order to identify a possible role of recombination in the response to the vaccine or the acquisition of an increased transmissibility. This study included 250 poliovirus isolates: 137 vaccine isolates, excreted by children during primary vaccination with OPV and 113 isolates obtained from acute flaccid paralytic (AFP) cases and healthy contacts. Recombination was first assessed using a double PCR-RFLP, and sequencing. Nineteen per cent of recombinant strains were identified: 20% of strains excreted by vaccinees among 18% of circulating strains. The proportion of recombinant in isolates of serotype1 was very low in the two groups while the proportions of recombinants in serotypes 2 and 3 were different. In vaccinees, the frequency of recombinants in serotype3 decreased during the course of vaccination: 54% after the first dose, 32% after the second and 14% after the third dose. These results suggest that recombination enhances the ability of serotype3 vaccine strains to induce an immune response. Apart from recent vaccination, it may contribute to a more effective transmissibility of vaccine strains among human population. Copyright © 2009 Elsevier Masson SAS. All rights reserved.

A Yersinia pestis YscN ATPase mutant functions as a live attenuated vaccine against bubonic plague in mice.

PubMed

Bozue, Joel; Cote, Christopher K; Webster, Wendy; Bassett, Anthony; Tobery, Steven; Little, Stephen; Swietnicki, Wieslaw

2012-07-01

Yersinia pestis is the causative agent responsible for bubonic and pneumonic plague. The bacterium uses the pLcr plasmid-encoded type III secretion system to deliver virulence factors into host cells. Delivery requires ATP hydrolysis by the YscN ATPase encoded by the yscN gene also on pLcr. A yscN mutant was constructed in the fully virulent CO92 strain containing a nonpolar, in-frame internal deletion within the gene. We demonstrate that CO92 with a yscN mutation was not able to secrete the LcrV protein (V-Antigen) and attenuated in a subcutaneous model of plague demonstrating that the YscN ATPase was essential for virulence. However, if the yscN mutant was complemented with a functional yscN gene in trans, virulence was restored. To evaluate the mutant as a live vaccine, Swiss-Webster mice were vaccinated twice with the ΔyscN mutant at varying doses and were protected against bubonic plague in a dose-dependent manner. Antibodies to F1 capsule but not to LcrV were detected in sera from the vaccinated mice. These preliminary results suggest a proof-of-concept for an attenuated, genetically engineered, live vaccine effective against bubonic plague. Published 2012. This article is a US Government work and is in the public domain in the USA.

Mumps vaccine virus strains and aseptic meningitis.

PubMed

Bonnet, Marie-Claude; Dutta, Anil; Weinberger, Clement; Plotkin, Stanley A

2006-11-30

Mumps immunization can easily be included in national schedules, particularly if combined with measles or measles and rubella vaccines, but debate continues concerning the relative safety of various licensed mumps vaccine strains. The opportunities for control of mumps are also being affected by differences in the cost of the vaccines prepared with different strains of mumps virus. The present report evaluates available data on the association of the Urabe and other strains of mumps vaccine with the occurrence of aseptic meningitis. We also review the comparative immunogenicity and efficacies of the most widely used mumps vaccines in controlled clinical trials and field evaluations, and briefly examine relative cost as it relates to the implementation of national immunization programs. We conclude that extensive experience with the most widely used mumps vaccine strains in many countries has shown that the risk-benefit ratio of live mumps vaccines is highly favourable for vaccination, despite the occasional occurence of aseptic meningitis.

Characterization of the Burkholderia mallei tonB Mutant and Its Potential as a Backbone Strain for Vaccine Development

PubMed Central

Mott, Tiffany M.; Vijayakumar, Sudhamathi; Sbrana, Elena; Endsley, Janice J.; Torres, Alfredo G.

2015-01-01

Background In this study, a Burkholderia mallei tonB mutant (TMM001) deficient in iron acquisition was constructed, characterized, and evaluated for its protective properties in acute inhalational infection models of murine glanders and melioidosis. Methodology/Principal Findings Compared to the wild-type, TMM001 exhibits slower growth kinetics, siderophore hyper-secretion and the inability to utilize heme-containing proteins as iron sources. A series of animal challenge studies showed an inverse correlation between the percentage of survival in BALB/c mice and iron-dependent TMM001 growth. Upon evaluation of TMM001 as a potential protective strain against infection, we found 100% survival following B. mallei CSM001 challenge of mice previously receiving 1.5 x 104 CFU of TMM001. At 21 days post-immunization, TMM001-treated animals showed significantly higher levels of B. mallei-specific IgG1, IgG2a and IgM when compared to PBS-treated controls. At 48 h post-challenge, PBS-treated controls exhibited higher levels of serum inflammatory cytokines and more severe pathological damage to target organs compared to animals receiving TMM001. In a cross-protection study of acute inhalational melioidosis with B. pseudomallei, TMM001-treated mice were significantly protected. While wild type was cleared in all B. mallei challenge studies, mice failed to clear TMM001. Conclusions/Significance Although further work is needed to prevent chronic infection by TMM001 while maintaining immunogenicity, our attenuated strain demonstrates great potential as a backbone strain for future vaccine development against both glanders and melioidosis. PMID:26114445

Characterization of the Burkholderia mallei tonB Mutant and Its Potential as a Backbone Strain for Vaccine Development.

PubMed

Mott, Tiffany M; Vijayakumar, Sudhamathi; Sbrana, Elena; Endsley, Janice J; Torres, Alfredo G

2015-01-01

In this study, a Burkholderia mallei tonB mutant (TMM001) deficient in iron acquisition was constructed, characterized, and evaluated for its protective properties in acute inhalational infection models of murine glanders and melioidosis. Compared to the wild-type, TMM001 exhibits slower growth kinetics, siderophore hyper-secretion and the inability to utilize heme-containing proteins as iron sources. A series of animal challenge studies showed an inverse correlation between the percentage of survival in BALB/c mice and iron-dependent TMM001 growth. Upon evaluation of TMM001 as a potential protective strain against infection, we found 100% survival following B. mallei CSM001 challenge of mice previously receiving 1.5 x 10(4) CFU of TMM001. At 21 days post-immunization, TMM001-treated animals showed significantly higher levels of B. mallei-specific IgG1, IgG2a and IgM when compared to PBS-treated controls. At 48 h post-challenge, PBS-treated controls exhibited higher levels of serum inflammatory cytokines and more severe pathological damage to target organs compared to animals receiving TMM001. In a cross-protection study of acute inhalational melioidosis with B. pseudomallei, TMM001-treated mice were significantly protected. While wild type was cleared in all B. mallei challenge studies, mice failed to clear TMM001. Although further work is needed to prevent chronic infection by TMM001 while maintaining immunogenicity, our attenuated strain demonstrates great potential as a backbone strain for future vaccine development against both glanders and melioidosis.

Rotavirus vaccine strain transmission by vaccinated infants in the foster home.

PubMed

Miura, Hiroki; Kawamura, Yoshiki; Sugata, Ken; Koshiyama, Nozomi; Yoshikawa, Akiko; Komoto, Satoshi; Taniguchi, Koki; Ihira, Masaru; Yoshikawa, Tetsushi

2017-01-01

Previous studies have demonstrated the transmission of rotavirus vaccine strains from vaccinated children to nonvaccinated siblings. We sought to fully elucidate the safety of rotavirus (RV) vaccination in closed contact circumstance, such as the foster home for future assessment of the vaccine safety in an neonatal intensive care unit. Stool samples were collected from 4 RV vaccinated (160 samples) and 23 unvaccinated (766 samples) infants. RV viral RNA loads were measured using real-time reverse transcription polymerase chain reaction (RT-PCR). RV vaccine strain RNA was persistently detected in stool samples collected from the four vaccine recipients and one unvaccinated infant, but not in the stool samples collected from the 22 other unvaccinated infants. The unvaccinated infant who tested positive for the RV vaccine strain was vaccinated prior to enrollment in this study. The quantitative real-time RT-PCR data revealed a peak viral RNA load 1 week after vaccination followed by a gradual decrease. The current study suggests that RV vaccination may be safe in a close contact environment because there was limited transmission from RV vaccinated to unvaccinated infants. J. Med. Virol. 89:79-84, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Burkholderia mallei CLH001 Attenuated Vaccine Strain Is Immunogenic and Protects against Acute Respiratory Glanders

PubMed Central

Hatcher, Christopher L.; Mott, Tiffany M.; Muruato, Laura A.; Sbrana, Elena

2016-01-01

Burkholderia mallei is the causative agent of glanders, an incapacitating disease with high mortality rates in respiratory cases. Its endemicity and ineffective treatment options emphasize its public health threat and highlight the need for a vaccine. Live attenuated vaccines are considered the most viable vaccine strategy for Burkholderia, but single-gene-deletion mutants have not provided complete protection. In this study, we constructed the select-agent-excluded B. mallei ΔtonB Δhcp1 (CLH001) vaccine strain and investigated its ability to protect against acute respiratory glanders. Here we show that CLH001 is attenuated, safe, and effective at protecting against lethal B. mallei challenge. Intranasal administration of CLH001 to BALB/c and NOD SCID gamma (NSG) mice resulted in complete survival without detectable colonization or abnormal organ histopathology. Additionally, BALB/c mice intranasally immunized with CLH001 in a prime/boost regimen were fully protected against lethal challenge with the B. mallei lux (CSM001) wild-type strain. PMID:27271739

Revealing Differences in Metabolic Flux Distributions between a Mutant Strain and Its Parent Strain Gluconacetobacter xylinus CGMCC 2955

PubMed Central

Liu, Miao; Yang, Xiao-Ning; Zhu, Hui-Xia; Jia, Yuan-Yuan; Jia, Shi-Ru; Piergiovanni, Luciano

2014-01-01

A better understanding of metabolic fluxes is important for manipulating microbial metabolism toward desired end products, or away from undesirable by-products. A mutant strain, Gluconacetobacter xylinus AX2-16, was obtained by combined chemical mutation of the parent strain (G. xylinus CGMCC 2955) using DEC (diethyl sulfate) and LiCl. The highest bacterial cellulose production for this mutant was obtained at about 11.75 g/L, which was an increase of 62% compared with that by the parent strain. In contrast, gluconic acid (the main byproduct) concentration was only 5.71 g/L for mutant strain, which was 55.7% lower than that of parent strain. Metabolic flux analysis indicated that 40.1% of the carbon source was transformed to bacterial cellulose in mutant strain, compared with 24.2% for parent strain. Only 32.7% and 4.0% of the carbon source were converted into gluconic acid and acetic acid in mutant strain, compared with 58.5% and 9.5% of that in parent strain. In addition, a higher flux of tricarboxylic acid (TCA) cycle was obtained in mutant strain (57.0%) compared with parent strain (17.0%). It was also indicated from the flux analysis that more ATP was produced in mutant strain from pentose phosphate pathway (PPP) and TCA cycle. The enzymatic activity of succinate dehydrogenase (SDH), which is one of the key enzymes in TCA cycle, was 1.65-fold higher in mutant strain than that in parent strain at the end of culture. It was further validated by the measurement of ATPase that 3.53–6.41 fold higher enzymatic activity was obtained from mutant strain compared with parent strain. PMID:24901455

Immunogenicity and protective efficacy of a Salmonella Enteritidis sptP mutant as a live attenuated vaccine candidate.

PubMed

Lin, Zhijie; Tang, Peipei; Jiao, Yang; Kang, Xilong; Li, Qiuchun; Xu, Xiulong; Sun, Jun; Pan, Zhiming; Jiao, Xinan

2017-06-24

Salmonella enterica serovar Enteritidis (S. Enteritidis) is a highly adaptive pathogen in both humans and animals. As a Salmonella Type III secretion system (T3SS) effector, Salmonella protein tyrosine phosphatase (SptP) is critical for virulence in this genus. To investigate the feasibility of using C50336ΔsptP as a live attenuated oral vaccine in mice, we generated the sptP gene deletion mutant C50336ΔsptP in S. Enteritidis strain C50336 by λ-Red mediated recombination and evaluated the protective ability of the S. Enteritidis sptP mutant strain C50336ΔsptP against mice salmonellosis. We found that C50336ΔsptP was a highly immunogenic, effective, and safe vaccine in mice. Compared to wild-type C50336, C50336ΔsptP showed reduced virulence as confirmed by the 50% lethal dose (LD 50 ) in orally infected mice. C50336ΔsptP also showed decreased bacterial colonization both in vivo and in vitro. Immunization with C50336ΔsptP had no significant effect on body weight and did not result in obvious clinical symptoms relative to control animals treated with phosphate-buffered saline (PBS), but induced humoral and cellular immune responses at 12 and 26 days post inoculation. Immunization with 1 × 10 8 colony-forming units (CFU) C50336ΔsptP per mouse provided 100% protection against subsequent challenge with the wild-type C50336 strain, and immunized mice showed mild and temporary clinical symptoms as compared to those of control group. These results demonstrate that C50336ΔsptP can be a live attenuated oral vaccine for salmonellosis.

A commercial PCV2a-based vaccine is effective in protection from experimental challenge of PCV2 mutant with two amino acids elongation in capsid protein.

PubMed

Guo, Long-Jun; Fu, Yu-Jie; Huang, Li-Ping; Wang, Yi-Ping; Wei, Yan-Wu; Wu, Hong-Li; Liu, Chang-Ming

2015-07-17

Current commercial PCV2 vaccines are almost based on PCV2a and have been shown to be effective in reducing PCV2a and PCV2b viremia and PCV2-associated lesions and diseases. The recent emergence of novel mutant PCV2 (mPCV2) strains and linkage of mPCV2 with cases of porcine circovirus associated disease (PCVAD) in pig herds have raised concerns over emergence of vaccine-escape mutants and reduced efficacy of PCV2a-based vaccines. The aim of this study was to determine the ability of a commercial PCV2a-based vaccine developed by our laboratory to protect conventional pigs against experimental challenge with mPCV2 at 9 weeks of age. Twenty 4-week-old pigs free of PCV2 infection were randomly divided into four treatment groups with 5 pigs each. Two groups were unvaccinated as positive and negative controls. Another two groups were vaccinated with the commercial PCV2a-based vaccine (PCV2-LG strain, China) at 4 weeks of age and identical booster immunization was conducted 3 weeks post primary immunization. At 9 weeks of age, all pigs except the negative control were challenged with a mutant PCV2b/YJ (mPCV2b/YJ) with two amino acids elongation in capsid protein. The experiment was terminated 28 days after challenge. Under the conditions of this study, vaccinated pigs were protected against PCV2 viremia and lesions whereas unvaccinated pigs were not. Moreover, mPCV2b/YJ infection was demonstrated in positive control and almost all had macroscopic or microscopic lesions consistent with PCVAD while negative control did not develop PCVAD. This study indicates that mPCV2b/YJ infection alone can trigger PCVAD development and that the commercial vaccine (PCV2-LG) is still effective in protecting conventional pigs against the emerging mPCV2b/YJ strain in China. Copyright © 2015. Published by Elsevier Ltd.

Leishmania infantum HSP70-II null mutant as candidate vaccine against leishmaniasis: a preliminary evaluation

PubMed Central

2011-01-01

Background Visceral leishmaniasis is the most severe form of leishmaniasis and no effective vaccine exists. The use of live attenuated vaccines is emerging as a promising vaccination strategy. Results In this study, we tested the ability of a Leishmania infantum deletion mutant, lacking both HSP70-II alleles (ΔHSP70-II), to provide protection against Leishmania infection in the L. major-BALB/c infection model. Administration of the mutant line by either intraperitoneal, intravenous or subcutaneous route invariably leads to the production of high levels of NO and the development in mice of type 1 immune responses, as determined by analysis of anti-Leishmania IgG subclasses. In addition, we have shown that ΔHSP70-II would be a safe live vaccine as immunodeficient SCID mice, and hamsters (Mesocricetus auratus), infected with mutant parasites did not develop any sign of pathology. Conclusions The results suggest that the ΔHSP70-II mutant is a promising and safe vaccine, but further studies in more appropriate animal models (hamsters and dogs) are needed to appraise whether this attenuate mutant would be useful as vaccine against visceral leishmaniasis. PMID:21794145

Leishmania infantum HSP70-II null mutant as candidate vaccine against leishmaniasis: a preliminary evaluation.

PubMed

Carrión, Javier; Folgueira, Cristina; Soto, Manuel; Fresno, Manuel; Requena, Jose M

2011-07-27

Visceral leishmaniasis is the most severe form of leishmaniasis and no effective vaccine exists. The use of live attenuated vaccines is emerging as a promising vaccination strategy. In this study, we tested the ability of a Leishmania infantum deletion mutant, lacking both HSP70-II alleles (ΔHSP70-II), to provide protection against Leishmania infection in the L. major-BALB/c infection model. Administration of the mutant line by either intraperitoneal, intravenous or subcutaneous route invariably leads to the production of high levels of NO and the development in mice of type 1 immune responses, as determined by analysis of anti-Leishmania IgG subclasses. In addition, we have shown that ΔHSP70-II would be a safe live vaccine as immunodeficient SCID mice, and hamsters (Mesocricetus auratus), infected with mutant parasites did not develop any sign of pathology. The results suggest that the ΔHSP70-II mutant is a promising and safe vaccine, but further studies in more appropriate animal models (hamsters and dogs) are needed to appraise whether this attenuate mutant would be useful as vaccine against visceral leishmaniasis.

Immunogenicity and protective efficacy of the Mycobacterium tuberculosis fadD26 mutant

PubMed Central

Infante, E; Aguilar, L D; Gicquel, B; Pando, R Hernandez

2005-01-01

The Mycobacterium tuberculosis fadD26 mutant has impaired synthesis of phthiocerol dimycocerosates (DIM) and is attenuated in BALB/c mice. Survival analysis following direct intratracheal infection confirmed the attenuation: 60% survival at 4 months post-infection versus 100% mortality at 9 weeks post-infection with the wild-type strain. The fadD26 mutant induced less pneumonia and larger DTH reactions. It induced lower but progressive production of interferon (IFN)-γ, interleukin (IL)-4 and tumour necrosis factor (TNF)-α. Used as a subcutaneous vaccine 60 days before intratracheal challenge with a hypervirulent strain of M. tuberculosis (Beijing code 9501000), the mutant induced a higher level of protection than did Bacille Calmette–Guérin (BCG). Seventy per cent of the mice vaccinated with the fadD26 mutant survived at 16 weeks after challenge compared to 30% of those vaccinated with BCG. Similarly, there was less tissue damage (pneumonia) and lower colony-forming units (CFU) in the mice vaccinated with the fadD26 mutant compared to the findings in mice vaccinated with BCG. These data suggest that DIM synthesis is important for the pathogenicity of M. tuberculosis, and that inactivation of DIM synthesis can increase the immunogenicity of live vaccines, and increase their ability to protect against tuberculosis. PMID:15958066

Construction of a Streptococcus agalactiae phoB mutant and evaluation of its potential as an attenuated modified live vaccine in golden pompano, Trachinotus ovatus.

PubMed

Cai, Xiaohui; Wang, Bei; Peng, Yinhui; Li, Yuan; Lu, Yishan; Huang, Yucong; Jian, Jichang; Wu, Zaohe

2017-04-01

Streptococcus agalactiae is a Gram-positive pathogen that can survive inside professional phagocytes and nonphagocytic cells to cause septicemia and meningoencephalitis in freshwater and marine fish. However, vaccines based on extracellular products (ECP) and formalin-killed whole S. agalactiae cells, as well as subunit vaccine are unable to protect fish from infection by variant serotypes S. agalactiae. The search for live attenuated vaccine with highly conserved and virulent-related genes is essential for producing a vaccine to help understand and control streptococcosis In this study, the phoB gene was cloned from pathogenic S. agalactiae TOS01 strain and the mutant strain SAΔphoB was constructed via allelic exchange mutagenesis. The results showed that the deduced amino acid of S. agalactiae TOS01 shares high similarities with other Streptococcus spp. and has high conserved response regulator receiver domain (REC) and DNA-binding effector domain of two-component system response regulators (Trans_reg_C). Cell adherence and invasion assays, challenge experiments and histopathological changes post-vaccination were performed and observed, the results showed that the mutant strain SAΔphoB has a lower adherence and invasion rate and less virulent than the wild type strain in golden pompano, and it doesn't induce clinical symptoms and obvious pathological changes in golden pompano, thereby indicating that the deletion of phoB affects the virulence and infectious capacity of S. agalactiae. Golden pompano vaccinated via intraperitoneal injection SAΔphoB had the relative percent survival value of 93.1% after challenge with TOS01, demonstrating its high potential as an effective attenuated live vaccine candidate. Real-time PCR assays showed that the SAΔphoB was able to enhance the expression of immune-related genes, including MHC-I, MyD88, IL-22 and IL-10 after vaccination, indicating that the SAΔphoB is able to induce humoral and cell-mediated immune response

Burkholderia mallei CLH001 Attenuated Vaccine Strain Is Immunogenic and Protects against Acute Respiratory Glanders.

PubMed

Hatcher, Christopher L; Mott, Tiffany M; Muruato, Laura A; Sbrana, Elena; Torres, Alfredo G

2016-08-01

Burkholderia mallei is the causative agent of glanders, an incapacitating disease with high mortality rates in respiratory cases. Its endemicity and ineffective treatment options emphasize its public health threat and highlight the need for a vaccine. Live attenuated vaccines are considered the most viable vaccine strategy for Burkholderia, but single-gene-deletion mutants have not provided complete protection. In this study, we constructed the select-agent-excluded B. mallei ΔtonB Δhcp1 (CLH001) vaccine strain and investigated its ability to protect against acute respiratory glanders. Here we show that CLH001 is attenuated, safe, and effective at protecting against lethal B. mallei challenge. Intranasal administration of CLH001 to BALB/c and NOD SCID gamma (NSG) mice resulted in complete survival without detectable colonization or abnormal organ histopathology. Additionally, BALB/c mice intranasally immunized with CLH001 in a prime/boost regimen were fully protected against lethal challenge with the B. mallei lux (CSM001) wild-type strain. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Immunogenicity and protection induced by a Mycobacterium tuberculosis sigE mutant in a BALB/c mouse model of progressive pulmonary tuberculosis.

PubMed

Hernandez Pando, Rogelio; Aguilar, Leon Diana; Smith, Issar; Manganelli, Riccardo

2010-07-01

Tuberculosis is still one of the main challenges to human global health, leading to about two million deaths every year. One of the reasons for its success is the lack of efficacy of the widely used vaccine Mycobacterium bovis BCG. In this article, we analyze the potential use of an attenuated mutant of Mycobacterium tuberculosis H37Rv lacking the sigma factor sigma(E) as a live vaccine. We have demonstrated that BALB/c mice infected by the intratracheal route with this mutant strain showed significantly higher survival rates and less tissue damage than animals infected with the parental or complemented mutant strain. Although animals infected with the sigE mutant had low bacillary loads, their lungs showed significantly higher production of the protective factors gamma interferon (IFN-gamma), tumor necrosis factor alpha (TNF-alpha), inducible nitric oxide synthase (iNOS), and beta-defensins than those of animals infected with the parental or complemented mutant strain. Moreover, we demonstrate that the sigE mutant, when inoculated subcutaneously, was more attenuated than BCG in immunodeficient nude mice, thus representing a good candidate for a novel attenuated live vaccine strain. Finally, when we used the sigE mutant as a subcutaneous vaccine, it was able to induce a higher level of protection than did BCG with both H37Rv and a highly virulent strain of M. tuberculosis (Beijing code 9501000). Taken together, our findings suggest that the sigE mutant is a very promising strain for the development of a new vaccine against tuberculosis.

Acute hepatitis B caused by a vaccine-escape HBV strain in vaccinated subject: sequence analysis and therapeutic strategy.

PubMed

Luongo, Monica; Critelli, Rosina; Grottola, Antonella; Gitto, Stefano; Bernabucci, Veronica; Bevini, Mirco; Vecchi, Chiara; Montagnani, Giuliano; Villa, Erica

2015-01-01

HBV vaccine contains the 'a' determinant region, the major immune-target of antibodies (anti-HBs). Failure of immunization may be caused by vaccine-induced or spontaneous 'a' determinant surface gene mutants. Here, we evaluate the possible lack of protection by HBV vaccine, describing the case of an acute hepatitis B diagnosed in a 55-year-old Caucasian male unpaid blood donor, vaccinated against HBV. Sequencing data for preS-S region revealed multiple point mutations. Of all the substitutions found, Q129H, located in the "a" determinant region of HBsAg, can alter antigenicity, leading to mutants. This mutant may cause vaccine failure especially when associated with high viremia of infecting source. Copyright © 2014 Elsevier B.V. All rights reserved.

Salmonella DNA Adenine Methylase Mutants Confer Cross-Protective Immunity

PubMed Central

Heithoff, Douglas M.; Enioutina, Elena Y.; Daynes, Raymond A.; Sinsheimer, Robert L.; Low, David A.; Mahan, Michael J.

2001-01-01

Salmonella isolates that lack or overproduce DNA adenine methylase (Dam) elicited a cross-protective immune response to different Salmonella serovars. The protection afforded by the Salmonella enterica serovar Typhimurium Dam vaccine was greater than that elicited in mice that survived a virulent infection. S. enterica serovar Typhimurium Dam mutant strains exhibited enhanced sensitivity to mediators of innate immunity such as antimicrobial peptides, bile salts, and hydrogen peroxide. Also, S. enterica serovar Typhimurium Dam− vaccines were not immunosuppressive; unlike wild-type vaccines, they failed to induce increased nitric oxide levels and permitted a subsequent robust humoral response to diptheria toxoid antigen in infected mice. Dam mutant strains exhibited a low-grade persistence which, coupled with the nonimmunosuppression and the ectopic protein expression caused by altered levels of Dam, may provide an expanded source of potential antigens in vaccinated hosts. PMID:11598044

Commercial PCV2a-based vaccines are effective in protecting naturally PCV2b-infected finisher pigs against experimental challenge with a 2012 mutant PCV2.

PubMed

Opriessnig, Tanja; Gerber, Priscilla F; Xiao, Chao-Ting; Halbur, Patrick G; Matzinger, Shannon R; Meng, Xiang-Jin

2014-07-23

Current commercial PCV2 vaccines are all based on PCV2a and have been shown to be effective in reducing PCV2a and PCV2b viremia and PCV2-associated lesions and disease. The recent emergence of novel mutant PCV2 (mPCV2) strains and linkage of mPCV2 with cases of porcine circovirus associated disease (PCVAD) in vaccinated herds have raised concerns over emergence of vaccine-escape mutants and reduced efficacy of PCV2a-based vaccines. The aim of this study was to determine the ability of three commercial PCV2a-based vaccines administered in the presence of an ongoing PCV2b infection and passively-acquired anti-PCV2 antibodies to protect conventional pigs against experimental challenge with mPCV2 at 11 weeks of age. Fifty naturally PCV2b-infected 2-week-old pigs were divided into five treatment groups with 10 pigs each. Pigs were unvaccinated (positive and negative controls) or vaccinated at 3 (VAC-A, VAC-B, VAC-C) and at 5 weeks of age (VAC-C). At 11 weeks of age, all pigs except the negative controls were challenged with a 2012 U.S. strain of mPCV2. The experiment was terminated 21 days after challenge. Under the conditions of this study, vaccinated pigs were protected against PCV2 viremia and lesions whereas non-vaccinated pigs were not. Moreover, concurrent PCV2b and mPCV2 infection was demonstrated in all positive controls and 3/10 had microscopic lesions consistent with PCVAD while negative controls infected with PCV2b alone did not develop PCVAD. The results indicate that concurrent PCV2b/mPCV2 infection can trigger PCVAD development and that commercial vaccines are effective in protecting conventional pigs against emerging mPCV2 strains. Copyright © 2014 Elsevier Ltd. All rights reserved.

[Comparison of genotype characteristics between the circulating mumps virus strain in Beijing area and the vaccine strain].

PubMed

Chen, Meng; Zhang, Tie-gang; Chen, Li-juan; Wu, Jiang; Yang, Jie; Zhang, Wei

2009-11-01

To compare the genetic characteristics of mumps virus strain circulating in Beijing with vaccine strain and to preliminarily analysis the reasons of vaccine ineffectiveness. The following methods were used: Isolation and identification of the mumps virus which had been circulating in Beijing, immunization history analysis, SH gene sequence analysis and comparison genotype homology with reference strains and analysis of the key amino acid sites of HN variation. In 38 mumps cases that virus had been isolated from, another seven cases were IgM negative. In 2007 and 2008, the positive rates on virus isolation, RT-PCR and IgM-decreased significantly, while the cases with immunization history had an increase. Cases without histories of vaccination had both higher positive rates on virus isolation and IgM. Thirty-eight strains belonged to F genotype virus, but vaccine strain was A genotype. The circulating viruses showed 5.6% sequence divergence on SH gene nucleotide and 16.0% - 18.1% from vaccine strain. Conservative hydrophobic amino acids on SH protein of some Beijing strains had changed. For example, there were 6 strains, from No.8: L-->F. The circulating viruses showed 2.3% sequence divergence on HN protein amino acid sequences and 4.2% - 5.3% from vaccine strain. Amino acids sites, which deciding the ability of cross-neutralization of the Beijing strains and vaccine strains were different. At the 354 and 356 sites, all the Beijing strains were different from the vaccine strains. The N-glycosylation sites on HN of Beijing strains were also different from those on vaccine strains. Locations 464 - 466 appeared to be NCS on Beijing strain, but locations 464 - 466 were NCR on the vaccine strains. Another 18 unknown function amino acids sites of all Beijing strains were different from those on vaccine strains. In recent years, genotype F became the main genotype of circulating strains in Beijing without genotype variation, but larger difference was found between them

Construction, characterization and evaluation of the protective efficacy of the Streptococcus suis double mutant strain ΔSsPep/ΔSsPspC as a live vaccine candidate in mice.

PubMed

Hu, Jin; You, Wujin; Wang, Bin; Hu, Xueying; Tan, Chen; Liu, Jinlin; Chen, Huanchun; Bei, Weicheng

2015-01-01

Streptococcus suis serotype 2 (S. suis 2) causes sepsis and meningitis in piglets and humans, and results in one of the most serious bacterial diseases affecting the production of commercial pigs around the world. Due to the failure of the current inactivated vaccine to protect against the disease, development of a new attenuated live vaccine against S. suis 2 by deleting essential virulence factors is urgently needed. We have previously reported the construction and characterization of an SsPep single gene deletion mutant strain ΔSsPep based on S. suis 2. Our previous results have shown that SsPep plays a critical role in the pathogenesis of S. suis 2. In this study, a precisely defined double-deletion mutant ΔSsPep/ΔSsPspC of S. suis 2 without antibiotic-resistance markers was constructed based on ΔSsPep, and the levels of virulence of the wild-type (WT) and ΔSsPep/ΔSsPspC were compared in a mouse experimental infection model. We demonstrated that the double mutant ΔSsPep/ΔSsPspC was less virulent than the WT, and could induce a noticeable antibody response. Analysis of IgG subclasses (IgG1 and IgG2a) indicated that both Th1 and Th2 responses were induced by ΔSsPep/ΔSsPspC, although the IgG2a (Th1) response predominated over the IgG1 (Th2) response. Moreover, ΔSsPep/ΔSsPspC could confer 90% protective efficacy against challenge with a lethal dose of fully virulent S. suis 2. Taken together, these data demonstrate that ΔSsPep/ΔSsPspC can be used as an effective live vaccine and provide a novel strategy against infection of S. suis 2. Copyright © 2014 Elsevier GmbH. All rights reserved.

Evaluation of protective efficacy of live attenuated Salmonella enterica serovar Gallinarum vaccine strains against fowl typhoid in chickens.

PubMed

Laniewski, Paweł; Mitra, Arindam; Karaca, Kemal; Khan, Ayub; Prasad, Rajeev; Curtiss, Roy; Roland, Kenneth L

2014-09-01

Salmonella enterica serovar Gallinarum is the etiological agent of fowl typhoid, which constitutes a considerable economic problem for poultry growers in developing countries. The vaccination of chickens seems to be the most effective strategy to control the disease in those areas. We constructed S. Gallinarum strains with a deletion of the global regulatory gene fur and evaluated their virulence and protective efficacy in Rhode Island Red chicks and Brown Leghorn layers. The fur deletion mutant was avirulent and, when delivered orally to chicks, elicited excellent protection against lethal S. Gallinarum challenge. It was not as effective when given orally to older birds, although it was highly immunogenic when delivered by intramuscular injection. We also examined the effect of a pmi mutant and a combination of fur deletions with mutations in the pmi and rfaH genes, which affect O-antigen synthesis, and ansB, whose product inhibits host T-cell responses. The S. Gallinarum Δpmi mutant was only partially attenuated, and the ΔansB mutant was fully virulent. The Δfur Δpmi and Δfur ΔansB double mutants were attenuated but not protective when delivered orally to the chicks. However, a Δpmi Δfur strain was highly immunogenic when administered intramuscularly. All together, our results show that the fur gene is essential for the virulence of S. Gallinarum, and the fur mutant is effective as a live recombinant vaccine against fowl typhoid. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Mumps Hoshino and Torii vaccine strains were distinguished from circulating wild strains.

PubMed

Sawada, Akihito; Yamaji, Yoshiaki; Nakayama, Tetsuo

2013-06-01

Aseptic meningitis and acute parotitis have been observed after mumps vaccination. Mumps outbreaks have been reported in Japan because of low vaccine coverage, and molecular differentiation is required to determine whether these cases are vaccine associated. RT-nested PCR was performed in the small hydrophobic gene region, and viruses were differentiated by restriction fragment length polymorphism assay. A total of 584 nucleotides were amplified. The PCR product of the Hoshino strain was cut into two fragments (313 and 271 nucleotides) by MfeI; that of the Torii strain was digested with EcoT22I, resulting in 332- and 252-nucleotide fragments. Both strains were genotype B and had an XbaI site, resulting in two fragments: 299 and 285 nucleotides. Current circulating wild types were cut only by XbaI or MfeI. However, the MfeI site of the wild types was different from that of the Hoshino strain, resulting in 451- and 133-nucleotide fragments. Using three restriction enzymes, two mumps vaccine strains were distinguished from wild types, and this separation was applied to the identification of vaccine-related adverse events.

Influenza virus surveillance, vaccine strain selection, and manufacture.

PubMed

Stöhr, Klaus; Bucher, Doris; Colgate, Tony; Wood, John

2012-01-01

As outlined in other chapters, the influenza virus, existing laboratory diagnostic abilities, and disease epidemiology have several peculiarities that impact on the timing and processes for the annual production of influenza vaccines. The chapter provides an overview on the key biological and other factors that influence vaccine production. They are the reason for an "annual circle race" beginning with global influenza surveillance during the influenza season in a given year to the eventual supply of vaccines 12 months later in time before the next seasonal outbreak and so on. As influenza vaccines are needed for the Northern and Southern Hemisphere outbreaks in fall and spring, respectively, global surveillance and vaccine production has become a year round business. Its highlights are the WHO recommendations on vaccine strains in February and September and the eventual delivery of vaccine doses in time before the coming influenza season. In between continues vaccine strain and epidemiological surveillance, preparation of new high growth reassortments, vaccine seed strain preparation and development of standardizing reagents, vaccine bulk production, fill-finishing and vaccine release, and in some regions, clinical trials for regulatory approval.

Genetic characterization of L-Zagreb mumps vaccine strain.

PubMed

Ivancic, Jelena; Gulija, Tanja Kosutic; Forcic, Dubravko; Baricevic, Marijana; Jug, Renata; Mesko-Prejac, Majda; Mazuran, Renata

2005-04-01

Eleven mumps vaccine strains, all containing live attenuated virus, have been used throughout the world. Although L-Zagreb mumps vaccine has been licensed since 1972, only its partial nucleotide sequence was previously determined (accession numbers , and ). Therefore, we sequenced the entire genome of L-Zagreb vaccine strain (Institute of Immunology Inc., Zagreb, Croatia). In order to investigate the genetic stability of the vaccine, sequences of both L-Zagreb master seed and currently produced vaccine batch were determined and no difference between them was observed. A phylogenetic analysis based on SH gene sequence has shown that L-Zagreb strain does not belong to any of established mumps genotypes and that it is most similar to old, laboratory preserved European strains (1950s-1970s). L-Zagreb nucleotide and deduced protein sequences were compared with other mumps virus sequences obtained from the GenBank. Emphasis was put on functionally important protein regions and known antigenic epitopes. The extensive comparisons of nucleotide and deduced protein sequences between L-Zagreb vaccine strain and other previously determined mumps virus sequences have shown that while the functional regions of HN, V, and L proteins are well conserved among various mumps strains, there can be a substantial amino acid difference in antigenic epitopes of all proteins and in functional regions of F protein. No molecular pattern was identified that can be used as a distinction marker between virulent and attenuated strains.

Immunization against Genital Herpes with a Vaccine Virus That has Defects in Productive and Latent Infection

NASA Astrophysics Data System (ADS)

da Costa, Xavier J.; Jones, Cheryl A.; Knipe, David M.

1999-06-01

An effective vaccine for genital herpes has been difficult to achieve because of the limited efficacy of subunit vaccines and the safety concerns about live viruses. As an alternative approach, mutant herpes simplex virus strains that are replication-defective can induce protective immunity. To increase the level of safety and to prove that replication was not needed for immunization, we constructed a mutant herpes simplex virus 2 strain containing two deletion mutations, each of which eliminated viral replication. The double-mutant virus induces protective immunity that can reduce acute viral shedding and latent infection in a mouse genital model, but importantly, the double-mutant virus shows a phenotypic defect in latent infection. This herpes vaccine strain, which is immunogenic but has defects in both productive and latent infection, provides a paradigm for the design of vaccines and vaccine vectors for other sexually transmitted diseases, such as AIDS.

Bivalent vaccination against pneumonic pasteurellosis in domestic sheep and goats with modified-live in-frame lktA deletion mutants of Mannheimia haemolytica.

PubMed

Briggs, Robert E; Hauglund, Melissa J; Maheswaran, Samuel K; Tatum, Fred M

2013-11-01

A temperature-sensitive shuttle vector, pBB80C, was utilized to generate in-frame deletion mutants of the leukotoxin structural gene (lktA) of Mannheimia haemolytica serotypes 1, 2, 5, 6, 7, 8, 9, and 12. Culture supernatants from the mutants contained a truncated protein with an approximate molecular weight of 66 kDa which was reactive to anti-leukotoxin monoclonal antibody. No protein reactive to anti-LktA monoclonal antibody was detected at the molecular weight 100-105 kDa of native LktA. Sheep and goats vaccinated intramuscularly with a mixture of serotypes 5 and 6 mutants were resistant to virulent challenge with a mixture of the wild-type parent strains. These vaccinates responded serologically to both vaccine serotypes and exhibited markedly-reduced lung lesion volume and pulmonary infectious load compared to control animals. Control animals yielded a mixture of serotypes from lung lobes, but the proportion even within an individual animal varied widely from 95% serotype 5-95% serotype 6. Cultures recovered from liver were homogeneous, but two animals yielded serotype 5 and the other two yielded serotype 6 in pure culture. Published by Elsevier Ltd.

Attenuated and Replication-Competent Vaccinia Virus Strains M65 and M101 with Distinct Biology and Immunogenicity as Potential Vaccine Candidates against Pathogens

PubMed Central

Sánchez-Sampedro, Lucas; Gómez, Carmen Elena; Mejías-Pérez, Ernesto; Pérez-Jiménez, Eva; Oliveros, Juan Carlos

2013-01-01

Replication-competent poxvirus vectors with an attenuation phenotype and with a high immunogenic capacity of the foreign expressed antigen are being pursued as novel vaccine vectors against different pathogens. In this investigation, we have examined the replication and immunogenic characteristics of two vaccinia virus (VACV) mutants, M65 and M101. These mutants were generated after 65 and 101 serial passages of persistently infected Friend erythroleukemia (FEL) cells. In cultured cells of different origins, the mutants are replication competent and have growth kinetics similar to or slightly reduced in comparison with those of the parental Western Reserve (WR) virus strain. In normal and immune-suppressed infected mice, the mutants showed different levels of attenuation and pathogenicity in comparison with WR and modified vaccinia Ankara (MVA) strains. Wide genome analysis after deep sequencing revealed selected genomic deletions and mutations in a number of viral open reading frames (ORFs). Mice immunized in a DNA prime/mutant boost regimen with viral vectors expressing the LACK (Leishmania homologue for receptors of activated C kinase) antigen of Leishmania infantum showed protection or a delay in the onset of cutaneous leishmaniasis. Protection was similar to that triggered by MVA-LACK. In immunized mice, both polyfunctional CD4+ and CD8+ T cells with an effector memory phenotype were activated by the two mutants, but the DNA-LACK/M65-LACK protocol preferentially induced CD4+ whereas DNA-LACK/M101-LACK preferentially induced CD8+ T cell responses. Altogether, our findings showed the adaptive changes of the WR genome during long-term virus-host cell interaction and how the replication competency of M65 and M101 mutants confers distinct biological properties and immunogenicity in mice compared to those of the MVA strain. These mutants could have applicability for understanding VACV biology and as potential vaccine vectors against pathogens and tumors. PMID

Benomyl-resistant mutant strain of Trichoderma sp. with increased mycoparasitic activity.

PubMed

Olejníková, P; Ondrusová, Z; Krystofová, S; Hudecová, D

2010-01-01

Application of UV radiation to the strain Trichoderma sp. T-bt (isolated from lignite) resulted in the T-brm mutant which was resistant to the systemic fungicide benomyl. The tub2 gene sequence in the T-brm mutant differed from the parent as well as the collection strain (replacing tyrosine with histidine in the TUB2 protein). Under in vitro conditions this mutant exhibited a higher mycoparasitic activity toward phytopathogenic fungi.

Titration of individual strains in trivalent live-attenuated influenza vaccine without neutralization.

PubMed

Sirinonthanawech, Naraporn; Surichan, Somchaiya; Namsai, Aphinya; Puthavathana, Pilaipan; Auewarakul, Prasert; Kongchanagul, Alita

2016-11-01

Formulation and quality control of trivalent live-attenuated influenza vaccine requires titration of infectivity of individual strains in the trivalent mix. This is usually performed by selective neutralization of two of the three strains and titration of the un-neutralized strain in cell culture or embryonated eggs. This procedure requires standard sera with high neutralizing titer against each of the three strains. Obtaining standard sera, which can specifically neutralize only the corresponding strain of influenza viruses and is able to completely neutralize high concentration of virus in the vaccine samples, can be a problem for many vaccine manufacturers as vaccine stocks usually have very high viral titers and complete neutralization may not be obtained. Here an alternative approach for titration of individual strain in trivalent vaccine without the selective neutralization is presented. This was done by detecting individual strains with specific antibodies in an end-point titration of a trivalent vaccine in cell culture. Similar titers were observed in monovalent and trivalent vaccines for influenza A H3N2 and influenza B strains, whereas the influenza A H1N1 strain did not grow well in cell culture. Viral interference among the vaccine strains was not observed. Therefore, providing that vaccine strains grow well in cell culture, this assay can reliably determine the potency of individual strains in trivalent live-attenuated influenza vaccines. Copyright © 2016 Elsevier B.V. All rights reserved.

Increased riboflavin production from activated bleaching earth by a mutant strain of Ashbya gossypii.

PubMed

Tajima, Satoshi; Itoh, Yoko; Sugimoto, Takashi; Kato, Tatsuya; Park, Enoch Y

2009-10-01

The production of riboflavin from vegetable oil was increased using a mutant strain of Ashbya gossypii. This mutant was generated by treating the wild-type strain with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Riboflavin production was 10-fold higher in the mutant compared to the wild-type strain. The specific intracellular catalase activity after 3 d of culture was 6-fold higher in the mutant than in the wild-type strain. For the mutant, riboflavin production in the presence of 40 mM hydrogen peroxide was 16% less than that in the absence of hydrogen peroxide, whereas it was 56% less for the wild-type strain. The isocitrate lyase (ICL) activity of the mutant was 0.26 mU/mg of protein during the active riboflavin production phase, which was 2.6-fold higher than the wild-type strain. These data indicate that the mutant utilizes the carbon flux from the TCA cycle to the glyoxylate cycle more efficiently than the wild-type strain, resulting in enhanced riboflavin production. This novel mutant has the potential to be of use for industrial-scale riboflavin production from waste-activated bleaching earth (ABE), thereby transforming a useless material into a valuable bioproduct.

Humoral response to calicivirus in captive tigers given a dual-strain vaccine.

PubMed

Harrison, Tara M; Harrison, Scott H; Sikarskie, James G; Armstrong, Douglas

2014-03-01

The current feline vaccine with a single strain of calicivirus has been used for captive tigers, yet it may not protect against virulent systemic calicivirus infections. A cross-institutional study investigated the humoral response to a new dual-strain, killed-virus calicivirus vaccine for nine captive tigers. The subspecies of these tigers were Amur (Panthera tigris altaica), Bengal (Panthera tigris tigris), and Malayan (Panthera tigris jacksoni). Serum neutralization titers for virulent feline calicivirus strain FCV-DD1 were higher following dual-strain vaccine administration. There were no reports of adverse vaccine reactions. Dual-strain vaccination may afford broadened cross-protection against different calicivirus strains and is desirable to reduce the risk of virulent systemic calicivirus disease in tigers.

An attenuated quadruple gene mutant of Mycobacterium tuberculosis imparts protection against tuberculosis in guinea pigs

PubMed Central

Chauhan, Priyanka

2018-01-01

ABSTRACT Previously we had developed a triple gene mutant of Mycobacterium tuberculosis (MtbΔmms) harboring disruption in three genes, namely mptpA, mptpB and sapM. Though vaccination with MtbΔmms strain induced protection in the lungs of guinea pigs, the mutant strain failed to control the hematogenous spread of the challenge strain to the spleen. Additionally, inoculation with MtbΔmms resulted in some pathological damage to the spleens in the early phase of infection. In order to generate a strain that overcomes the pathology caused by MtbΔmms in spleen of guinea pigs and controls dissemination of the challenge strain, MtbΔmms was genetically modified by disrupting bioA gene to generate MtbΔmmsb strain. Further, in vivo attenuation of MtbΔmmsb was evaluated and its protective efficacy was assessed against virulent M. tuberculosis challenge in guinea pigs. MtbΔmmsb mutant strain was highly attenuated for growth and virulence in guinea pigs. Vaccination with MtbΔmmsb mutant generated significant protection in comparison to sham-immunized animals at 4 and 12 weeks post-infection in lungs and spleen of infected animals. However, the protection imparted by MtbΔmmsb was significantly less in comparison to BCG immunized animals. This study indicates the importance of attenuated multiple gene deletion mutants of M. tuberculosis for generating protection against tuberculosis. PMID:29242198

Vaccination with a HSV-2 UL24 mutant induces a protective immune response in murine and guinea pig vaginal infection models.

PubMed

Visalli, Robert J; Natuk, Robert J; Kowalski, Jacek; Guo, Min; Blakeney, Susan; Gangolli, Seema; Cooper, David

2014-03-10

The rational design and development of genetically attenuated HSV-2 mutant viruses represent an attractive approach for developing both prophylactic and therapeutic vaccines for genital herpes. Previously, HSV-2 UL24 was shown to be a virulence determinant in both murine and guinea pig vaginal infection models. An UL24-βgluc insertion mutant produced syncytial plaques and replicated to nearly wild type levels in tissue culture, but induced little or no pathological effects in recipient mice or guinea pigs following vaginal infection. Here we report that immunization of mice or guinea pigs with high or low doses of UL24-βgluc elicited a highly protective immune response. UL24-βgluc immunization via the vaginal or intramuscular routes was demonstrated to protect mice from a lethal vaginal challenge with wild type HSV-2. Moreover, antigen re-stimulated splenic lymphocytes harvested from immunized mice exhibited both HSV-2 specific CTL activity and IFN-γ expression. Humoral anti-HSV-2 responses in serum were Th1-polarized (IgG2a>IgG1) and contained high-titer anti-HSV-2 neutralizing activity. Guinea pigs vaccinated subcutaneously with UL24-βgluc or the more virulent parental strain (186) were challenged with a heterologous HSV-2 strain (MS). Acute disease scores were nearly indistinguishable in guinea pigs immunized with either virus. Recurrent disease scores were reduced in UL24-βgluc immunized animals but not to the same extent as those immunized with strain 186. In addition, challenge virus was not detected in 75% of guinea pigs subcutaneously immunized with UL24-βgluc. In conclusion, disruption of the UL24 gene is a prime target for the development of a genetically attenuated live HSV-2 vaccine. Copyright © 2014 Elsevier Ltd. All rights reserved.

Hereditary Hemochromatosis Restores the Virulence of Plague Vaccine Strains

PubMed Central

Quenee, Lauriane E.; Hermanas, Timothy M.; Ciletti, Nancy; Louvel, Helene; Miller, Nathan C.; Elli, Derek; Blaylock, Bill; Mitchell, Anthony; Schroeder, Jay; Krausz, Thomas; Kanabrocki, Joseph; Schneewind, Olaf

2012-01-01

Nonpigmented Yersinia pestis (pgm) strains are defective in scavenging host iron and have been used in live-attenuated vaccines to combat plague epidemics. Recently, a Y. pestis pgm strain was isolated from a researcher with hereditary hemochromatosis who died from laboratory-acquired plague. We used hemojuvelin-knockout (Hjv−/−) mice to examine whether iron-storage disease restores the virulence defects of nonpigmented Y. pestis. Unlike wild-type mice, Hjv−/− mice developed lethal plague when challenged with Y. pestis pgm strains. Immunization of Hjv−/− mice with a subunit vaccine that blocks Y. pestis type III secretion generated protection against plague. Thus, individuals with hereditary hemochromatosis may be protected with subunit vaccines but should not be exposed to live-attenuated plague vaccines. PMID:22896664

Immunization by intrabronchial administration to 1-week-old foals of an unmarked double gene disruption strain of Rhodococcus equi strain 103+.

PubMed

Pei, Yanlong; Nicholson, Vivian; Woods, Katharine; Prescott, John F

2007-11-15

Rhodococcus equi causes fatal granulomatous pneumonia in foals and immunocompromised animals and humans. However, there is no effective vaccine against this infection. In this study, the chromosomal genes isocitrate lyase (icl) and cholesterol oxidase (choE) were chosen as targets for mutation and assessment of the double mutant as an intrabronchial vaccine in 1-week-old foals. Using a modification of a suicide plasmid previously developed in this laboratory, we developed a choE-icl unmarked deletion mutant of R. equi strain 103+. Five 1-week-old foals were infected intrabronchially with the mutant and challenged intrabronchially with the parent, virulent, strain 2 weeks later. Three of the foals were protected against pneumonia caused by the virulent strain, but the other two foals developed pneumonia caused by the mutant strain during the post-challenge period. Since infection of 3-week-old foals by an icl mutant in an earlier study had shown complete attenuation of the strain, we conclude that a proportion of foals in the 1st week or so of life are predisposed to developing R. equi pneumonia because of an inability to mount an effective immune response. This has been suspected previously but this is the first time that this has been demonstrated experimentally.

Generation by Reverse Genetics of an Effective, Stable, Live-Attenuated Newcastle Disease Virus Vaccine Based on a Currently Circulating, Highly Virulent Indonesian Strain

PubMed Central

Xiao, Sa; Nayak, Baibaswata; Samuel, Arthur; Paldurai, Anandan; Kanabagattebasavarajappa, Mallikarjuna; Prajitno, Teguh Y.; Bharoto, Eny E.; Collins, Peter L.; Samal, Siba K.

2012-01-01

Newcastle disease virus (NDV) can cause severe disease in chickens. Although NDV vaccines exist, there are frequent reports of outbreaks in vaccinated chickens. During 2009–2010, despite intense vaccination, NDV caused major outbreaks among commercial poultry farms in Indonesia. These outbreaks raised concern regarding the protective immunity of current vaccines against circulating virulent strains in Indonesia. In this study, we investigated whether a recombinant attenuated Indonesian NDV strain could provide better protection against prevalent Indonesian viruses. A reverse genetics system for the highly virulent NDV strain Banjarmasin/010/10 (Ban/010) isolated in Indonesia in 2010 was constructed. The Ban/010 virus is classified in genotype VII of class II NDV, which is genetically distinct from the commercial vaccine strains B1 and LaSota, which belong to genotype II, and shares only 89 and 87% amino acid identity for the protective antigens F and HN, respectively. A mutant virus, named Ban/AF, was developed in which the virulent F protein cleavage site motif “RRQKR↓F” was modified to an avirulent motif “GRQGR↓L” by three amino acid substitutions (underlined). The Ban/AF vaccine virus did not produce syncytia or plaques in cell culture, even in the presence of added protease. Pathogenicity tests showed that Ban/AF was completely avirulent. Ban/AF replicated efficiently during 10 consecutive passages in chickens and remained genetically stable. Serological analysis showed that Ban/AF induced higher neutralization and hemagglutination inhibition antibody titers against the prevalent viruses than the commercial vaccines B1 or LaSota. Both Ban/AF and commercial vaccines provided protection against clinical disease and mortality after challenge with virulent NDV strain Ban/010 (genotype VII) or GB Texas (genotype II). However, Ban/AF significantly reduced challenge virus shedding from the vaccinated birds compared to B1 vaccine. These results suggest

Genetic heterogeneity of L-Zagreb mumps virus vaccine strain.

PubMed

Kosutic-Gulija, Tanja; Forcic, Dubravko; Santak, Maja; Ramljak, Ana; Mateljak-Lukacevic, Sanja; Mazuran, Renata

2008-07-10

The most often used mumps vaccine strains Jeryl Lynn (JL), RIT4385, Urabe-AM9, L-Zagreb and L-3 differ in immunogenicity and reactogenicity. Previous analyses showed that JL, Urabe-AM9 and L-3 are genetically heterogeneous. We identified the heterogeneity of L-Zagreb throughout the entire genome. Two major variants were defined: variant A being identical to the consensus sequence of viral seeds and vaccine(s) and variant B which differs from variant A in three nucleotide positions. The difference between viral variants in L-Zagreb strain is insufficient for distinct viral strains to be defined. We demonstrated that proportion of variants in L-Zagreb viral population depends on cell substrate used for viral replication in vitro and in vivo. L-Zagreb strain should be considered as a single strain composed of at least two variant viral genomes.

Identification of vaccine-derived rotavirus strains in children with acute gastroenteritis in Japan, 2012-2015.

PubMed

Kaneko, Mei; Takanashi, Sayaka; Thongprachum, Aksara; Hanaoka, Nozomu; Fujimoto, Tsuguto; Nagasawa, Koo; Kimura, Hirokazu; Okitsu, Shoko; Mizuguchi, Masashi; Ushijima, Hiroshi

2017-01-01

Two live attenuated oral rotavirus vaccines, Rotarix and RotaTeq, have been introduced as voluntary vaccination in Japan since 2011 and 2012, respectively. Effectiveness of the vaccines has been confirmed, whereas concerns such as shedding of the vaccine strains and gastroenteritis cases caused by vaccine strains are not well assessed. We aimed to identify the vaccine strains in children with acute gastroenteritis (AGE) to investigate the prevalence of AGE caused by vaccination or horizontal transmission of vaccine strains. A total of 1,824 stool samples were collected from children with AGE at six outpatient clinics in 2012-2015. Among all, 372 group A rotavirus (RVA) positive samples were screened for vaccine components by real-time RT-PCR which were designed to differentiate vaccine strains from rotavirus wild-type strains with high specificity. For samples possessing both vaccine and wild-type strains, analyses by next-generation sequencing (NGS) were conducted to characterize viruses existed in the intestine. As a result, Rotarix-derived strains were identified in 6 of 372 (1.6%) RVA positive samples whereas no RotaTeq strain was detected. Among six samples, four possessed Rotarix-derived strains while two possessed both Rotarix-derived strains and wild-type strains. In addition, other pathogens such as norovirus, enterovirus and E.coli were detected in four samples. The contribution of these vaccine strains to each patient's symptoms was unclear as all of the cases were vaccinated 2-14 days before sample collection. Proportion of average coverage for each segmented gene by NGS strongly suggested the concurrent infection of the vaccine-derived strain and the wild-type strain rather than reassortment of these two strains in one sample. This is the first study to report the prevalence of vaccine-derived strains in patients with RVA AGE in Japan as 1.6% without evidence of horizontal transmission. The results emphasized the importance of continuous monitoring on

Identification of vaccine-derived rotavirus strains in children with acute gastroenteritis in Japan, 2012-2015

PubMed Central

Kaneko, Mei; Thongprachum, Aksara; Hanaoka, Nozomu; Fujimoto, Tsuguto; Nagasawa, Koo; Kimura, Hirokazu; Okitsu, Shoko; Mizuguchi, Masashi; Ushijima, Hiroshi

2017-01-01

Two live attenuated oral rotavirus vaccines, Rotarix and RotaTeq, have been introduced as voluntary vaccination in Japan since 2011 and 2012, respectively. Effectiveness of the vaccines has been confirmed, whereas concerns such as shedding of the vaccine strains and gastroenteritis cases caused by vaccine strains are not well assessed. We aimed to identify the vaccine strains in children with acute gastroenteritis (AGE) to investigate the prevalence of AGE caused by vaccination or horizontal transmission of vaccine strains. A total of 1,824 stool samples were collected from children with AGE at six outpatient clinics in 2012–2015. Among all, 372 group A rotavirus (RVA) positive samples were screened for vaccine components by real-time RT-PCR which were designed to differentiate vaccine strains from rotavirus wild-type strains with high specificity. For samples possessing both vaccine and wild-type strains, analyses by next-generation sequencing (NGS) were conducted to characterize viruses existed in the intestine. As a result, Rotarix-derived strains were identified in 6 of 372 (1.6%) RVA positive samples whereas no RotaTeq strain was detected. Among six samples, four possessed Rotarix-derived strains while two possessed both Rotarix-derived strains and wild-type strains. In addition, other pathogens such as norovirus, enterovirus and E.coli were detected in four samples. The contribution of these vaccine strains to each patient’s symptoms was unclear as all of the cases were vaccinated 2–14 days before sample collection. Proportion of average coverage for each segmented gene by NGS strongly suggested the concurrent infection of the vaccine-derived strain and the wild-type strain rather than reassortment of these two strains in one sample. This is the first study to report the prevalence of vaccine-derived strains in patients with RVA AGE in Japan as 1.6% without evidence of horizontal transmission. The results emphasized the importance of continuous

Genetic heterogeneity of L-Zagreb mumps virus vaccine strain

PubMed Central

Kosutic-Gulija, Tanja; Forcic, Dubravko; Šantak, Maja; Ramljak, Ana; Mateljak-Lukacevic, Sanja; Mazuran, Renata

2008-01-01

Background The most often used mumps vaccine strains Jeryl Lynn (JL), RIT4385, Urabe-AM9, L-Zagreb and L-3 differ in immunogenicity and reactogenicity. Previous analyses showed that JL, Urabe-AM9 and L-3 are genetically heterogeneous. Results We identified the heterogeneity of L-Zagreb throughout the entire genome. Two major variants were defined: variant A being identical to the consensus sequence of viral seeds and vaccine(s) and variant B which differs from variant A in three nucleotide positions. The difference between viral variants in L-Zagreb strain is insufficient for distinct viral strains to be defined. We demonstrated that proportion of variants in L-Zagreb viral population depends on cell substrate used for viral replication in vitro and in vivo. Conclusion L-Zagreb strain should be considered as a single strain composed of at least two variant viral genomes. PMID:18616793

Phylogenetic analysis of Hungarian goose parvovirus isolates and vaccine strains.

PubMed

Tatár-Kis, Tímea; Mató, Tamás; Markos, Béla; Palya, Vilmos

2004-08-01

Polymerase chain reaction and sequencing were used to analyse goose parvovirus field isolates and vaccine strains. Two fragments of the genome were amplified. Fragment "A" represents a region of VP3 gene, while fragment "B" represents a region upstream of the VP3 gene, encompassing part of the VP1 gene. In the region of fragment "A" the deduced amino acid sequence of the strains was identical, therefore differentiation among strains could be done only at the nucleotide level, which resulted in the formation of three groups: Hungarian, West-European and Asian strains. In the region of fragment "B", separation of groups could be done by both nucleotide and deduced amino acid sequence level. The nucleotide sequences resulted in the same groups as for fragment "A" but with a different clustering pattern among the Hungarian strains. Within the "Hungarian" group most of the recent field isolates fell into one cluster, very closely related or identical to each other, indicating a very slow evolutionary change. The attenuated strains and field isolates from 1979/80 formed a separate cluster. When vaccine strains and field isolates were compared, two specific amino acid differences were found that can be considered as possible markers for vaccinal strains. Sequence analysis of fragment "B" seems to be a suitable method for differentiation of attenuated vaccine strains from virulent strains. Copyright 2004 Houghton Trust Ltd

Molecular typing of Brucella melitensis endemic strains and differentiation from the vaccine strain Rev-1.

PubMed

Noutsios, Georgios T; Papi, Rigini M; Ekateriniadou, Loukia V; Minas, Anastasios; Kyriakidis, Dimitrios A

2012-03-01

In the present study forty-four Greek endemic strains of Br. melitensis and three reference strains were genotyped by Multi locus Variable Number Tandem Repeat (ML-VNTR) analysis based on an eight-base pair tandem repeat sequence that was revealed in eight loci of Br. melitensis genome. The forty-four strains were discriminated from the vaccine strain Rev-1 by Restriction Fragment Length Polymorphism (RFLP) and Denaturant Gradient Gel Electrophoresis (DGGE). The ML-VNTR analysis revealed that endemic, reference and vaccine strains are genetically closely related, while most of the loci tested (1, 2, 4, 5 and 7) are highly polymorphic with Hunter-Gaston Genetic Diversity Index (HGDI) values in the range of 0.939 to 0.775. Analysis of ML-VNTRs loci stability through in vitro passages proved that loci 1 and 5 are non stable. Therefore, vaccine strain can be discriminated from endemic strains by allele's clusters of loci 2, 4, 6 and 7. RFLP and DGGE were also employed to analyse omp2 gene and reveled different patterns among Rev-1 and endemic strains. In RFLP, Rev-1 revealed three fragments (282, 238 and 44 bp), while endemic strains two fragments (238 and 44 bp). As for DGGE, the electrophoretic mobility of Rev-1 is different from the endemic strains due to heterologous binding of DNA chains of omp2a and omp2b gene. Overall, our data show clearly that it is feasible to genotype endemic strains of Br. melitensis and differentiate them from vaccine strain Rev-1 with ML-VNTR, RFLP and DGGE techniques. These tools can be used for conventional investigations in brucellosis outbreaks.

Comparison of the live attenuated yellow fever vaccine 17D-204 strain to its virulent parental strain Asibi by deep sequencing.

PubMed

Beck, Andrew; Tesh, Robert B; Wood, Thomas G; Widen, Steven G; Ryman, Kate D; Barrett, Alan D T

2014-02-01

The first comparison of a live RNA viral vaccine strain to its wild-type parental strain by deep sequencing is presented using as a model the yellow fever virus (YFV) live vaccine strain 17D-204 and its wild-type parental strain, Asibi. The YFV 17D-204 vaccine genome was compared to that of the parental strain Asibi by massively parallel methods. Variability was compared on multiple scales of the viral genomes. A modeled exploration of small-frequency variants was performed to reconstruct plausible regions of mutational plasticity. Overt quasispecies diversity is a feature of the parental strain, whereas the live vaccine strain lacks diversity according to multiple independent measurements. A lack of attenuating mutations in the Asibi population relative to that of 17D-204 was observed, demonstrating that the vaccine strain was derived by discrete mutation of Asibi and not by selection of genomes in the wild-type population. Relative quasispecies structure is a plausible correlate of attenuation for live viral vaccines. Analyses such as these of attenuated viruses improve our understanding of the molecular basis of vaccine attenuation and provide critical information on the stability of live vaccines and the risk of reversion to virulence.

Brunenders: a partially attenuated historic poliovirus type I vaccine strain.

PubMed

Sanders, Barbara P; Liu, Ying; Brandjes, Alies; van Hoek, Vladimir; de Los Rios Oakes, Isabel; Lewis, John; Wimmer, Eckard; Custers, Jerome H H V; Schuitemaker, Hanneke; Cello, Jeronimo; Edo-Matas, Diana

2015-09-01

Brunenders, a type I poliovirus (PV) strain, was developed in 1952 by J. F. Enders and colleagues through serial in vitro passaging of the parental Brunhilde strain, and was reported to display partial neuroattenuation in monkeys. This phenotype of attenuation encouraged two vaccine manufacturers to adopt Brunenders as the type I component for their inactivated poliovirus vaccines (IPVs) in the 1950s, although today no licensed IPV vaccine contains Brunenders. Here we confirmed, in a transgenic mouse model, the report of Enders on the reduced neurovirulence of Brunenders. Although dramatically neuroattenuated relative to WT PV strains, Brunenders remains more virulent than the attenuated oral vaccine strain, Sabin 1. Importantly, the neuroattenuation of Brunenders does not affect in vitro growth kinetics and in vitro antigenicity, which were similar to those of Mahoney, the conventional type I IPV vaccine strain. We showed, by full nucleotide sequencing, that Brunhilde and Brunenders differ at 31 nucleotides, eight of which lead to amino acid changes, all located in the capsid. Upon exchanging the Brunenders capsid sequence with that of the Mahoney capsid, WT neurovirulence was regained in vivo, suggesting a role for the capsid mutations in Brunenders attenuation. To date, as polio eradication draws closer, the switch to using attenuated strains for IPV is actively being pursued. Brunenders preceded this novel strategy as a partially attenuated IPV strain, accompanied by decades of successful use in the field. Providing data on the attenuation of Brunenders may be of value in the further construction of attenuated PV strains to support the grand pursuit of the global eradication of poliomyelitis.

Lights and shades on an historical vaccine canine distemper virus, the Rockborn strain.

PubMed

Martella, V; Blixenkrone-Møller, M; Elia, G; Lucente, M S; Cirone, F; Decaro, N; Nielsen, L; Bányai, K; Carmichael, L E; Buonavoglia, C

2011-02-01

Both egg- and cell-adapted canine distemper virus (CDV) vaccines are suspected to retain residual virulence, especially if administered to immuno-suppressed animals, very young pups or to highly susceptible animal species. In the early 1980s, post-vaccine encephalitis was reported in dogs from various parts of Britain after administration of a particular batch of combined CDV Rockborn strain/canine adenovirus type-1 vaccine, although incrimination of the Rockborn strain was subsequently retracted. Notwithstanding, this, and other reports, led to the view that the Rockborn strain is less attenuated and less safe than other CDV vaccines, and the Rockborn strain was officially withdrawn from the markets in the mid 1990s. By sequencing the H gene of the strain Rockborn from the 46th laboratory passage, and a commercial vaccine (Candur(®) SH+P, Hoechst Rousell Vet GmbH), the virus was found to differ from the commonly used vaccine strain, Onderstepoort (93.0% nt and 91.7% aa), and to resemble more closely (99.6% nt and 99.3% aa) a CDV strain detected in China from a Lesser Panda (Ailurus fulgens). An additional four CDV strains matching (>99% nt identity) the Rockborn virus were identified in the sequence databases. Also, Rockborn-like strains were identified in two vaccines currently in the market. These findings indicate that Rockborn-like viruses may be recovered from dogs or other carnivores with distemper, suggesting cases of residual virulence of vaccines, or circulation of vaccine-derived Rockborn-like viruses in the field. Copyright © 2010 Elsevier Ltd. All rights reserved.

Aerogenic vaccination with a Burkholderia mallei auxotroph protects against aerosol-initiated glanders in mice.

PubMed

Ulrich, Ricky L; Amemiya, Kei; Waag, David M; Roy, Chad J; DeShazer, David

2005-03-14

Burkholderia mallei is an obligate mammalian pathogen that causes the zoonotic disease glanders. Two live attenuated B. mallei strains, a capsule mutant and a branched-chain amino acid auxotroph, were evaluated for use as vaccines against aerosol-initiated glanders in mice. Animals were aerogenically vaccinated and serum samples were obtained before aerosol challenge with a high-dose (>300 times the LD50) of B. mallei ATCC 23344. Mice vaccinated with the capsule mutant developed a Th2-like Ig subclass antibody response and none survived beyond 5 days. In comparison, the auxotrophic mutant elicited a Th1-like Ig subclass antibody response and 25% of the animals survived for 1 month postchallenge. After a low-dose (5 times the LD50) aerosol challenge, the survival rates of auxotroph-vaccinated and unvaccinated animals were 50 and 0%, respectively. Thus, live attenuated strains that promote a Th1-like Ig response may serve as promising vaccine candidates against aerosol infection with B. mallei.

Comparison of the Live Attenuated Yellow Fever Vaccine 17D-204 Strain to Its Virulent Parental Strain Asibi by Deep Sequencing

PubMed Central

Beck, Andrew; Tesh, Robert B.; Wood, Thomas G.; Widen, Steven G.; Ryman, Kate D.; Barrett, Alan D. T.

2014-01-01

Background. The first comparison of a live RNA viral vaccine strain to its wild-type parental strain by deep sequencing is presented using as a model the yellow fever virus (YFV) live vaccine strain 17D-204 and its wild-type parental strain, Asibi. Methods. The YFV 17D-204 vaccine genome was compared to that of the parental strain Asibi by massively parallel methods. Variability was compared on multiple scales of the viral genomes. A modeled exploration of small-frequency variants was performed to reconstruct plausible regions of mutational plasticity. Results. Overt quasispecies diversity is a feature of the parental strain, whereas the live vaccine strain lacks diversity according to multiple independent measurements. A lack of attenuating mutations in the Asibi population relative to that of 17D-204 was observed, demonstrating that the vaccine strain was derived by discrete mutation of Asibi and not by selection of genomes in the wild-type population. Conclusions. Relative quasispecies structure is a plausible correlate of attenuation for live viral vaccines. Analyses such as these of attenuated viruses improve our understanding of the molecular basis of vaccine attenuation and provide critical information on the stability of live vaccines and the risk of reversion to virulence. PMID:24141982

Efficacy of vaccination with La Sota strain vaccine to control Newcastle disease in village chickens in Nepal.

PubMed

Shrestha, Sulochana; Dhawan, Mamta; Donadeu, Meritxell; Dungu, Baptiste

2017-02-01

The efficacy of vaccination with Newcastle disease (ND) La Sota and R 2 B (Mukteswar) modified live strain vaccines was determined by experimental challenge and with ND La Sota vaccine under field conditions in Nepal. Booster vaccination with ND La Sota vaccine after a primary vaccination with ND La Sota vaccine, induced a geometric mean titre (GMT) of 5.0 log 2 haemagglutination inhibition (HI) units, compared to a GMT of 6.0 log 2 HI units following booster vaccination with R 2 B vaccine 1 month after primary vaccination with ND La Sota vaccine. Both vaccines provided 100% protection against challenge with a local field ND strain. Furthermore, booster vaccination with ND La Sota vaccine induced protective levels of antibody after field use in villages in Jhapa, and no outbreaks of ND occurred during the study period. The ND La Sota modified live vaccine is immunogenic and efficacious and is a suitable vaccine for use in vaccination programmes in village chickens in the rural areas of Nepal.

Comparative analysis of the Rotarix™ vaccine strain and G1P[8] rotaviruses detected before and after vaccine introduction in Belgium.

PubMed

Zeller, Mark; Heylen, Elisabeth; Tamim, Sana; McAllen, John K; Kirkness, Ewen F; Akopov, Asmik; De Coster, Sarah; Van Ranst, Marc; Matthijnssens, Jelle

2017-01-01

G1P[8] rotaviruses are responsible for the majority of human rotavirus infections worldwide. The effect of universal mass vaccination with rotavirus vaccines on circulating G1P[8] rotaviruses is still poorly understood. Therefore we analyzed the complete genomes of the Rotarix™ vaccine strain, and 70 G1P[8] rotaviruses, detected between 1999 and 2010 in Belgium (36 before and 34 after vaccine introduction) to investigate the impact of rotavirus vaccine introduction on circulating G1P[8] strains. All rotaviruses possessed a complete Wa-like genotype constellation, but frequent intra-genogroup reassortments were observed as well as multiple different cluster constellations circulating in a single season. In addition, identical cluster constellations were found to circulate persistently over multiple seasons. The Rotarix™ vaccine strain possessed a unique cluster constellation that was not present in currently circulating G1P[8] strains. At the nucleotide level, the VP6, VP2 and NSP2 gene segments of Rotarix™ were relatively distantly related to any Belgian G1P[8] strain, but other gene segments of Rotarix™ were found in clusters also containing circulating Belgian strains. At the amino acid level, the genetic distance between Rotarix™ and circulating Belgian strains was considerably lower, except for NSP1. When we compared the Belgian G1P[8] strains collected before and after vaccine introduction a reduction in the proportion of strains that were found in the same cluster as the Rotarix™ vaccine strain was observed for most gene segments. The reduction in the proportion of strains belonging to the same cluster may be the result of the vaccine introduction, although natural fluctuations cannot be ruled out.

Comparative analysis of pentavalent rotavirus vaccine strains and G8 rotaviruses identified during vaccine trial in Africa.

PubMed

Heylen, Elisabeth; Zeller, Mark; Ciarlet, Max; Lawrence, Jody; Steele, Duncan; Van Ranst, Marc; Matthijnssens, Jelle

2015-10-06

RotaTeqTM is a pentavalent rotavirus vaccine based on a bovine rotavirus genetic backbone in vitro reassorted with human outer capsid genes. During clinical trials of RotaTeqTM in Sub-Saharan Africa, the vaccine efficacy over a 2-year follow-up was lower against the genotypes contained in the vaccine than against the heterotypic G8P[6] and G8P[1] rotavirus strains of which the former is highly prevalent in Africa. Complete genome analyses of 43 complete rotavirus genomes collected during phase III clinical trials of RotaTeqTM in Sub-Saharan Africa, were conducted to gain insight into the high level of cross-protection afforded by RotaTeqTM against these G8 strains. Phylogenetic analysis revealed the presence of a high number of bovine rotavirus gene segments in these human G8 strains. In addition, we performed an in depth analysis on the individual amino acid level which showed that G8 rotaviruses were more similar to the RotaTeqTM vaccine than non-G8 strains. Because RotaTeqTM possesses a bovine genetic backbone, the high vaccine efficacy against G8 strains might be partially explained by the fact that all these strains contain a complete or partial bovine-like backbone. Altogether, this study supports the hypothesis that gene segments other than VP7 and VP4 play a role in vaccine-induced immunity.

Proteomic analysis of Mycoplasma gallisepticum vaccine strain F

USDA-ARS?s Scientific Manuscript database

The persistence and displacement abilities of the Mycoplasma gallisepticum vaccine strain F (F-strain) are well documented. Understanding the mechanism(s) of colonization and persistence of F-strain will aid in the current intervention strategies to diagnose and control MG infections in poultry. In ...

Mutant strain of C. acetobutylicum and process for making butanol

DOEpatents

Jain, Mahendra K.; Beacom, Daniel; Datta, Rathin

1993-01-01

A biologically pure asporogenic mutant of Clostridium acetobutylicum is produced by growing sporogenic C. acetobutylicum ATCC 4259 and treating the parent strain with ethane methane sulfonate. The mutant which as been designated C. acetobutylicum ATCC 55025 is useful in an improved ABE fermentation process, and produces high concentrations of butanol and total solvents.

Strain-specific reverse transcriptase PCR assay: means to distinguish candidate vaccine from wild-type strains of respiratory syncytial virus.

PubMed Central

Zheng, H; Peret, T C; Randolph, V B; Crowley, J C; Anderson, L J

1996-01-01

Candidate live-virus vaccines for respiratory syncytial virus are being developed and are beginning to be evaluated in clinical trials. To distinguish candidate vaccine strains from wild-type strains isolated during these trials, we developed PCR assays specific to two sets of candidate vaccine strains. The two sets were a group A strain (3A), its three attenuated, temperature-sensitive variant strains, a group B strain (2B), and its four attenuated, temperature-sensitive variant strains. The PCR assays were evaluated by testing 18 group A wild-type strains, the 3A strains, 9 group B wild-type strains, and the 2B strains. PCR specific to group A wild-type strains amplified only group A wild-type strains, and 3A-specific PCR amplified only 3A strains. PCR specific to group B wild-type strains amplified all group A and group B strains but gave a 688-bp product for group B wild-type strains, a 279-bp product for 2B strains, a 547-bp product for all group A strains, and an additional 688-bp product for some group A strains, including 3A strains. These types of PCR assays can, in conjunction with other methods, be used to efficiently distinguish candidate vaccine strains from other respiratory syncytial virus strains. PMID:8789010

Immunogenicity of a meningococcal native outer membrane vesicle vaccine with attenuated endotoxin and over-expressed factor H binding protein in infant rhesus monkeys

PubMed Central

Koeberling, Oliver; Seubert, Anja; Santos, George; Colaprico, Annalisa; Ugozzoli, Mildred; Donnelly, John; Granoff, Dan M.

2011-01-01

We previously investigated immunogenicity of meningococcal native outer membrane vesicle (NOMV) vaccines prepared from recombinant strains with attenuated endotoxin (ΔLpxL1) and over-expressed factor H binding protein (fHbp) in a mouse model. The vaccines elicited broad serum bactericidal antibody responses. While human toll-like receptor 4 (TLR-4) is mainly stimulated by wildtype meningococcal endotoxin, mouse TLR-4 is stimulated by both the wildtype and mutant endotoxin. An adjuvant effect in mice of the mutant endotoxin would be expected to be much less in humans, and may have contributed to the broad mouse bactericidal responses. Here we show that as previously reported for humans, rhesus primate peripheral blood mononuclear cells incubated with a NOMV vaccine from ΔLpxL1 recombinant strains had lower proinflammatory cytokine responses than with a control wildtype NOMV vaccine. The cytokine responses to the mutant vaccine were similar to those elicited by a detergent-treated, wildtype outer membrane vesicle vaccine that had been safely administered to humans. Monkeys (N=4) were immunized beginning at ages 2 to 3 months with three doses of a NOMV vaccine prepared from ΔLpxL1 recombinant strains with over-expressed fHbp in the variant 1 and 2 groups. The mutant NOMV vaccine elicited serum bactericidal titers ≥1:4 against all 10 genetically diverse strains tested, including 9 with heterologous PorA to those in the vaccine. Negative-control animals had serum bactericidal titers <1:4. Thus, the mutant NOMV vaccine elicited broadly protective serum antibodies in a non-human infant primate model that is more relevant for predicting human antibody responses than mice. PMID:21571025

A wide extent of inter-strain diversity in virulent and vaccine strains of alphaherpesviruses.

PubMed

Szpara, Moriah L; Tafuri, Yolanda R; Parsons, Lance; Shamim, S Rafi; Verstrepen, Kevin J; Legendre, Matthieu; Enquist, L W

2011-10-01

Alphaherpesviruses are widespread in the human population, and include herpes simplex virus 1 (HSV-1) and 2, and varicella zoster virus (VZV). These viral pathogens cause epithelial lesions, and then infect the nervous system to cause lifelong latency, reactivation, and spread. A related veterinary herpesvirus, pseudorabies (PRV), causes similar disease in livestock that result in significant economic losses. Vaccines developed for VZV and PRV serve as useful models for the development of an HSV-1 vaccine. We present full genome sequence comparisons of the PRV vaccine strain Bartha, and two virulent PRV isolates, Kaplan and Becker. These genome sequences were determined by high-throughput sequencing and assembly, and present new insights into the attenuation of a mammalian alphaherpesvirus vaccine strain. We find many previously unknown coding differences between PRV Bartha and the virulent strains, including changes to the fusion proteins gH and gB, and over forty other viral proteins. Inter-strain variation in PRV protein sequences is much closer to levels previously observed for HSV-1 than for the highly stable VZV proteome. Almost 20% of the PRV genome contains tandem short sequence repeats (SSRs), a class of nucleic acids motifs whose length-variation has been associated with changes in DNA binding site efficiency, transcriptional regulation, and protein interactions. We find SSRs throughout the herpesvirus family, and provide the first global characterization of SSRs in viruses, both within and between strains. We find SSR length variation between different isolates of PRV and HSV-1, which may provide a new mechanism for phenotypic variation between strains. Finally, we detected a small number of polymorphic bases within each plaque-purified PRV strain, and we characterize the effect of passage and plaque-purification on these polymorphisms. These data add to growing evidence that even plaque-purified stocks of stable DNA viruses exhibit limited sequence

A novel live attenuated anthrax spore vaccine based on an acapsular Bacillus anthracis Sterne strain with mutations in the htrA, lef and cya genes.

PubMed

Chitlaru, Theodor; Israeli, Ma'ayan; Rotem, Shahar; Elia, Uri; Bar-Haim, Erez; Ehrlich, Sharon; Cohen, Ofer; Shafferman, Avigdor

2017-10-20

We recently reported the development of a novel, next-generation, live attenuated anthrax spore vaccine based on disruption of the htrA (High Temperature Requirement A) gene in the Bacillus anthracis Sterne veterinary vaccine strain. This vaccine exhibited a highly significant decrease in virulence in murine, guinea pig and rabbit animal models yet preserved the protective value of the parental Sterne strain. Here, we report the evaluation of additional mutations in the lef and cya genes, encoding for the toxin components lethal factor (LF) and edema factor (EF), to further attenuate the SterneΔhtrA strain and improve its compatibility for human use. Accordingly, we constructed seven B. anthracis Sterne-derived strains exhibiting different combinations of mutations in the htrA, cya and lef genes. The various strains were indistinguishable in growth in vitro and in their ability to synthesise the protective antigen (PA, necessary for the elicitation of protection). In the sensitive murine model, we observed a gradual increase (ΔhtrA<ΔhtrAΔcya<ΔhtrAΔlef<ΔhtrAΔlefΔcya) in attenuation - up to 10 8 -fold relative to the parental Sterne vaccine strain. Most importantly, all various SterneΔhtrA derivative strains did not differ in their ability to elicit protective immunity in guinea pigs. Immunisation of guinea pigs with a single dose (10 9 spores) or double doses (>10 7 spores) of the most attenuated triple mutant strain SterneΔhtrAlef MUT Δcya induced a robust immune response, providing complete protection against a subsequent respiratory lethal challenge. Partial protection was observed in animals vaccinated with a double dose of as few as 10 5 spores. Furthermore, protective immune status was maintained in all vaccinated guinea pigs and rabbits for at least 40 and 30weeks, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

Toward the development of a stable, freeze-dried formulation of Helicobacter pylori killed whole cell vaccine adjuvanted with a novel mutant of E. coli heat-labile toxin

PubMed Central

Summerton, Nancy A.; Welch, Richard W.; Bondoc, Laureano; Yang, Huei-Hsiung; Pleune, Brett; Ramachandran, Naryaswamy; Harris, Andrea M.; Bland, Desiree; Jackson, W. James; Park, Sukjoon; Clements, John D.; Nabors, Gary S.

2009-01-01

No vaccine exists for the prevention of infection with the ubiquitous gastric pathogen Helicobacter pylori, and drug therapy for the infection is complicated by poor patient compliance, the high cost of treatment, and ineffectiveness against drug resistant strains. A new medical advancement is required to reduce the incidence of peptic ulcer disease and stomach cancer, two conditions caused by infection with H. pylori. Clinical trials have been performed with a formalin-inactivated Helicobacter pylori Whole Cell (HWC) vaccine, given orally in combination with the mucosal adjuvant mLT(R192G), a mutant of E. coli heat-labile toxin. Following the initial dose of this vaccine, some subjects experienced gastrointestinal side effects. To reduce side effects and potentially further increase the amount of adjuvant that can safely be administered with the HWC vaccine, experiments were performed with a form of LT that carried two mutations in the A subunit, a substitution of G for R at position 192, and A for L at position 211. The double-mutant LT (dmLT) adjuvant stimulated immune responses as effectively as the single mutant LT in mice. Additionally, following a challenge infection, the dmLT-adjuvanted vaccine was as effective as single mutant LT in reducing gastric urease levels (diagnostic for H. pylori infection), and H. pylori colonization in the stomach as assessed by quantitative analysis of stomach homogenates. A lyophilized formulation of HWC was developed to improve stability and to potentially reduce reliance on cold chain maintenance. It was observed that a dmLT-adjuvanted lyophilized vaccine was equally as protective in the mouse model as the liquid formulation as assessed by gastric urease analysis and analysis of stomach homogenates for viable H. pylori. No readily detectable effect of tonicity or moisture content was observed for the lyophilized vaccine within the formulation limits evaluated. In an accelerated stability study performed at 37°C the

Rotavirus A genotype G1P[8]: a novel method to distinguish wild-type strains from the Rotarix vaccine strain.

PubMed

Rose, Tatiana L; Miagostovich, Marize P; Leite, José Paulo G

2010-12-01

Rotaviruses are important enteric pathogens for humans and animals. Group A rotaviruses (RV-A) are the most common agents of severe gastroenteritis in infants and young children and vaccination is the most effective method to reduce RV-A-associated diseases. G1P[8], the most prevalent RV-A genotype worldwide, is included in the RV-A vaccine Rotarix®. The discrimination between wild-type G1P[8] and vaccine G1P[8] strains is an important topic in the study of RV-A epidemiology to manage outbreaks and to define control measures for vaccinated children. In this study, we developed a novel method to segregate the wild-type and vaccine strains using restriction endonucleases. The dsRNA from the Rotarix® vaccine was sequenced and the NSP3 gene was selected as the target gene. The vaccine strain has a restriction pattern that is different than that of wild-type RV-A G1P[8] isolates after digestion with the restriction endonuclease BspHI. This pattern could be used as a marker for the differentiation of wild-type G1P[8] strains from the vaccine strain.

Occult hepatitis B virus infection and S gene escape mutants in HIV-infected patients after hepatitis B virus vaccination.

PubMed

Aghakhani, Arezoo; Mohraz, Minoo; Aghasadeghi, Mohammad Reza; Banifazl, Mohammad; Vahabpour, Rouhollah; Karami, Afsaneh; Foroughi, Maryam; Ramezani, Amitis

2016-10-01

Hepatitis B virus (HBV) vaccination is recommended for HIV patients. Despite the relative success of HBV vaccination, breakthrough infections can occur infrequently in patients, and it can be due to occult HBV infection, vaccine unresponsiveness and/or emergence of escape mutants. This study assessed the presence of occult HBV infection and S gene escape mutants in HIV-positive patients after HBV vaccination. Ninety-two HIV-positive patients were enrolled in this study, including 52 responders to HBV vaccine and 40 non-responders. All of the cases received HBV vaccine according to routine HBV vaccination protocols. The presence of HBV-DNA was determined by real-time polymerase chain reaction (PCR). In HBV-DNA positive samples, the most conserved regions of S gene sequences were amplified by nested PCR and PCR products were sequenced. Occult HBV infection was detected in two cases. Glycine to arginine mutation at residue 145 (G145R) within the 'a' region of the S gene was detected in one of the occult HBV infection cases who was in the non-responder group. This study showed that the prevalence of occult HBV infection and vaccine escape mutants was low in our HBV-vaccinated HIV-positive patients in both responder and non-responder groups, so there was no alarming evidence indicating breakthrough HBV infection in our vaccinated HIV-positive cases. © The Author(s) 2016.

Are vaccine strain, type or administration protocol risk factors for canine parvovirus vaccine failure?

PubMed

Altman, K D; Kelman, M; Ward, M P

2017-10-01

Canine parvovirus (CPV) is a highly contagious and worldwide cause of serious and often fatal disease in dogs, despite the widespread availability of vaccines. Which vaccine-related factors are associated with vaccination failure is largely unknown, and there are no reports from Australia. In this study - the first national population-level CPV study of its kind ever conducted - we analysed data on 594 cases of apparent CPV vaccination failure reported from an Australian national surveillance system to determine whether vaccine strain, type or administration protocol are risk factors for vaccination failures. The strain of CPV used in vaccine manufacture was not significantly associated with vaccination failure in clinical practice. The vaccine type (killed versus attenuated vaccine) for puppies diagnosed with CPV was associated with a lower mean age at time of vaccination (P=0.0495). The age at administration of the last CPV vaccination a puppy received prior to presenting with disease was a significant (P=0.0334) risk factor for vaccination failure, irrespective of whether the vaccine was marketed for a 10-week or 12-week or greater vaccination finish protocol. There was also a strong negative correlation between age at last vaccination prior to disease and vaccination failure (P<0.0001): the later a puppy received this last vaccination, the lower the risk of vaccination failure. This supports the hypothesis that the use of final vaccination in puppies at less than 16 weeks of age predisposes to vaccination failure and warrants a final age for vaccination recommendation to be at least 16 weeks for all canine parvovirus vaccines, especially in outbreak situations. The large number of cases identified in this study confirms that CPV vaccination failure is occurring in Australia. Veterinarians should consider CPV as a differential diagnosis in cases with appropriate clinical presentation, regardless of the reported vaccination status of the dog. Copyright © 2017

Which influenza vaccine formulation should be used in Kenya? A comparison of influenza isolates from Kenya to vaccine strains, 2007-2013.

PubMed

Waiboci, Lilian W; Mott, Joshua A; Kikwai, Gilbert; Arunga, Geoffrey; Xu, Xiyan; Mayieka, Lilian; Emukule, Gideon O; Muthoka, Phillip; Njenga, M Kariuki; Fields, Barry S; Katz, Mark A

2016-05-17

Every year the World Health Organization (WHO) recommends which influenza virus strains should be included in a northern hemisphere (NH) and a southern hemisphere (SH) influenza vaccine. To determine the best vaccine formulation for Kenya, we compared influenza viruses collected in Kenya from April 2007 to May 2013 to WHO vaccine strains. We collected nasopharyngeal and oropharyngeal (NP/OP) specimens from patients with respiratory illness, tested them for influenza, isolated influenza viruses from a proportion of positive specimens, tested the isolates for antigenic relatedness to vaccine strains, and determined the percentage match between circulating viruses and SH or NH influenza vaccine composition and schedule. During the six years, 7.336 of the 60,072 (12.2%) NP/OP specimens we collected were positive for influenza: 30,167 specimens were collected during the SH seasons and 3717 (12.3%) were positive for influenza; 2903 (78.1%) influenza A, 902 (24.2%) influenza B, and 88 (2.4%) influenza A and B positive specimens. We collected 30,131 specimens during the NH seasons and 3978 (13.2%) were positive for influenza; 3181 (80.0%) influenza A, 851 (21.4%) influenza B, and 54 (1.4%) influenza A and B positive specimens. Overall, 362/460 (78.7%) isolates from the SH seasons and 316/338 (93.5%) isolates from the NH seasons were matched to the SH and the NH vaccine strains, respectively (p<0.001). Overall, 53.6% and 46.4% SH and NH vaccines, respectively, matched circulating strains in terms of vaccine strains and timing. In six years of surveillance in Kenya, influenza circulated at nearly equal levels during the SH and the NH influenza seasons. Circulating viruses were matched to vaccine strains. The vaccine match decreased when both vaccine strains and timing were taken into consideration. Either vaccine formulation could be suitable for use in Kenya but the optimal timing for influenza vaccination needs to be determined. Copyright © 2016 Elsevier Ltd. All rights

Evaluation of hha and hha sepB mutant strains of Escherichia coli O157:H7 as bacterins for reducing E. coli O157:H7 shedding in cattle.

PubMed

Sharma, Vijay K; Dean-Nystrom, Evelyn A; Casey, Thomas A

2011-07-12

Escherichia coli O157:H7 colonizes cattle intestines by using the locus of enterocyte effacement (LEE)-encoded proteins. The induction of systemic immune response against LEE-encoded proteins, therefore, will prove effective in reducing E. coli O157:H7 colonization in cattle. The previous studies have demonstrated that a hha (encodes for a hemolysin expression modulating protein) deletion enhances expression of LEE-encoded proteins and a sepB (encodes an ATPase required for the secretion of LEE-encoded proteins) deletion results in intracellular accumulation of LEE proteins. In this study, we demonstrate the efficacy of the hha and hha sepB deletion mutants as bacterins for reducing fecal shedding of E. coli O157:H7 in experimentally inoculated weaned calves. The weaned calves were injected intramuscularly with the bacterins containing 10(9) heat-killed cells of the hha(+) wild-type or hha or hha sepB isogenic mutants, and boosted with the same doses 2- and 4-weeks later. The evaluation of the immune response two weeks after the last booster immunization revealed that the calves vaccinated with the hha mutant bacterin had higher antibody titers against LEE proteins compared to the titers for these antibodies in the calves vaccinated with the hha sepB mutant or hha(+) wild-type bacterins. Following oral inoculations with 10(10) CFU of the wild-type E. coli O157:H7, the greater numbers of calves in the group vaccinated with the hha or hha sepB mutant bacterins stopped shedding the inoculum strain within a few days after the inoculations compared to the group of calves vaccinated with the hha(+) wild-type bacterin or PBS sham vaccine. Thus, the use of bacterins prepared from the hha and hha sepB mutants for reducing colonization of E. coli O157:H7 in cattle could represent a potentially important pre-harvest strategy to enhance post-harvest safety of bovine food products, water and produce. Copyright © 2011 Elsevier Ltd. All rights reserved.

Mutations in the haemagglutinin protein and their effect in transmission of highly pathogenic avian influenza (HPAI) H5N1 virus in sub-optimally vaccinated chickens.

PubMed

Sitaras, Ioannis; Rousou, Xanthoula; Peeters, Ben; de Jong, Mart C M

2016-11-04

Transmission of highly pathogenic avian influenza (HPAI) viruses in poultry flocks is associated with huge economic losses, culling of millions of birds, as well as human infections and deaths. In the cases where vaccination against avian influenza is used as a control measure, it has been found to be ineffective in preventing transmission of field strains. Reports suggest that one of the reasons for this is the use of vaccine doses much lower than the ones recommended by the manufacturer, resulting in very low levels of immunity. In a previous study, we selected for immune escape mutants using homologous polyclonal sera and used them as vaccines in transmission experiments. We concluded that provided a threshold of immunity is reached, antigenic distance between vaccine and challenge strains due to selection need not result in vaccine escape. Here, we evaluate the effect that the mutations in the haemagglutinin protein of our most antigenically-distant mutant may have in the transmission efficiency of this mutant to chickens vaccinated against the parent strain, under sub-optimal vaccination conditions resembling those often found in the field. In this study we employed reverse genetics techniques and transmission experiments to examine if the HA mutations of our most antigenically-distant mutant affect its efficiency to transmit to vaccinated chickens. In addition, we simulated sub-optimal vaccination conditions in the field, by using a very low vaccine dose. We find that the mutations in the HA protein of our most antigenically-distant mutant are not enough to allow it to evade even low levels of vaccination-induced immunity. Our results suggest that - for the antigenic distances we investigated - vaccination can reduce transmission of an antigenically-distant strain compared to the unvaccinated groups, even when low vaccine doses are used, resulting in low levels of immunity. Copyright © 2016 Elsevier Ltd. All rights reserved.

The Bulgarian vaccine Crimean-Congo haemorrhagic fever virus strain.

PubMed

Papa, Anna; Papadimitriou, Evangelia; Christova, Iva

2011-03-01

The Crimean-Congo haemorrhagic fever virus (CCHFV) is a 3-segmented RNA virus, which causes disease with a high fatality rate in humans. An inactivated suckling mouse brain-derived vaccine is used in Bulgaria for protection against CCHF. Strain V42/81 is currently used for the vaccine preparation. As the M-RNA segment plays a major role in the immune response, the full-length M segment sequence of the V42/81 strain was characterized. A great genetic diversity was observed among CCHFV strains. In order to gain an insight into the topology of the strain in the CCHFV phylogenetic trees, the full-length S and partial L segments were additionally sequenced and analyzed.

Identification and development of a promising novel mumps vaccine candidate strain.

PubMed

Liang, Yan; Ma, Shaohui; Liu, Longding; Zhao, Hongling; Wang, Lichun; Jiang, Li; Xie, Zhongping; Dong, Chenghong; Li, Qihan

2010-12-01

Mumps epidemics are usually caused by airborne transmission of mumps virus (MuV) and have high morbidity in non-immunized children. Epidemiological studies in many regions of China show that the genotype F viral strain is the most prevalent. However, the genotype A strain is currently used to prepare vaccines. Regional epidemiological MuV data suggest a significant application for the development of live attenuated mumps vaccines targeting specific genotypes. This article reports the isolation and culture of a genotype F MuV candidate strain that could be used to prepare a live attenuated mumps vaccine. This strain is shown to have good immunological efficacy and stability in neurovirulence evaluations. This work should facilitate the implementation of mumps vaccination in mainland China by targeting the most prevalent MuV genotype, genotype F. Copyright © 2010 Institut Pasteur. Published by Elsevier SAS. All rights reserved.

Vaccine-induced rabies case in a cow (Bos taurus): Molecular characterisation of vaccine strain in brain tissue.

PubMed

Vuta, Vlad; Picard-Meyer, Evelyne; Robardet, Emmanuelle; Barboi, Gheorghe; Motiu, Razvan; Barbuceanu, Florica; Vlagioiu, Constantin; Cliquet, Florence

2016-09-22

Rabies is a fatal neuropathogenic zoonosis caused by the rabies virus of the Lyssavirus genus, Rhabdoviridae family. The oral vaccination of foxes - the main reservoir of rabies in Europe - using a live attenuated rabies virus vaccine was successfully conducted in many Western European countries. In July 2015, a rabies vaccine strain was isolated from the brain tissues of a clinically suspect cow (Bos taurus) in Romania. The nucleotide analysis of both N and G gene sequences showed 100% identity between the rabid animal, the GenBank reference SAD B19 strain and five rabies vaccine batches used for the national oral vaccination campaign targeting foxes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Herpes zoster caused by vaccine-strain varicella zoster virus in an immunocompetent recipient of zoster vaccine.

PubMed

Tseng, Hung Fu; Schmid, D Scott; Harpaz, Rafael; LaRussa, Philip; Jensen, Nancy J; Rivailler, Pierre; Radford, Kay; Folster, Jennifer; Jacobsen, Steven J

2014-04-01

We report the first laboratory-documented case of herpes zoster caused by the attenuated varicella zoster virus (VZV) contained in Zostavax in a 68-year-old immunocompetent adult with strong evidence of prior wild-type VZV infection. The complete genome sequence of the isolate revealed that the strain carried 15 of 42 (36%) recognized varicella vaccine-associated single-nucleotide polymorphisms, including all 5 of the fixed vaccine markers present in nearly all of the strains in the vaccine. The case of herpes zoster was relatively mild and resolved without complications.

Correlation of mutations and recombination with growth kinetics of poliovirus vaccine strains.

PubMed

Pliaka, V; Kyriakopoulou, Z; Tsakogiannis, D; Ruether, I G A; Gartzonika, C; Levidiotou-Stefanou, S; Krikelis, A; Markoulatos, P

2010-12-01

Attenuated strains of Sabin poliovirus vaccine replicate in the human gut and, in rare cases, may cause vaccine-associated paralytic poliomyelitis (VAPP). The genetic instability of Sabin strains constitutes one of the main causes of VAPP, a disease that is most frequently associated with type 3 and type 2 Sabin strains, and more rarely with type 1 Sabin strains. In the present study, the growth phenotype of eight oral poliovirus vaccine (OPV) isolates (two non-recombinants and six recombinants), as well as of Sabin vaccine strains, was evaluated using two different assays, the reproductive capacity at different temperatures (Rct) test and the one-step growth curve test in Hep-2 cells at two different temperatures (37°C and 40°C). The growth phenotype of isolates was correlated with genomic modifications in order to identify the determinants and mechanisms of reversion towards neurovirulence. All of the recombinant OPV isolates showed a thermoresistant phenotype in the Rct test. Moreover, both recombinant Sabin-3 isolates showed significantly higher viral yield than Sabin 3 vaccine strain at 37°C and 40°C in the one-step growth curve test. All of the OPV isolates displayed mutations at specific sites of the viral genome, which are associated with the attenuated and temperature-sensitive phenotype of Sabin strains. The results showed that both mutations and recombination events could affect the phenotype traits of Sabin derivatives and may lead to the reversion of vaccinal strains to neurovirulent ones. The use of phenotypic markers along with the genomic analysis may shed additional light on the molecular determinants of the reversed neurovirulent phenotype of Sabin derivatives.

Correlation of RNA secondary structure and attenuation of Sabin vaccine strains of poliovirus in tissue culture.

PubMed

Macadam, A J; Ferguson, G; Burlison, J; Stone, D; Skuce, R; Almond, J W; Minor, P D

1992-08-01

Part of the 5' noncoding regions of all three Sabin vaccine strains of poliovirus contains determinants of attenuation that are shown here to influence the ability of these strains to grow at elevated temperatures in BGM cells. The predicted RNA secondary structure of this region (nt 464-542 in P3/Sabin) suggests that both phenotypes are due to perturbation of base-paired stems. Ts phenotypes of site-directed mutants with defined changes in this region correlated well with predicted secondary structure stabilities. Reversal of base-pair orientation had little effect whereas stem disruption led to marked increases in temperature sensitivity. Phenotypic revertants of such viruses displayed mutations on either side of the stem. Mutations destabilizing stems led to intermediate phenotypes. These results provided evidence for the biological significance of the predicted RNA secondary structure.

Foot and mouth disease vaccine strain selection: Current approaches and future perspectives.

PubMed

Mahapatra, Mana; Parida, Satya

2018-06-27

Lack of cross protection between foot and mouth disease (FMD) virus (FMDV) serotypes as well as incomplete protection between some subtypes of FMDV affect the application of vaccine in the field. Further, the emergence of new variant FMD viruses periodically makes the existing vaccine inefficient. Consequently, periodical vaccine strain selection either by in vivo methods or in vitro methods become an essential requirement to enable utilisation of appropriate and efficient vaccines. Areas covered: Here we describe the cross reactivity of the existing vaccines with the global pool of circulating viruses and the putative selected vaccine strains for targeting protection against the two major circulating serotype O and A FMD viruses for East Africa, the Middle East, South Asia and South East Asia. Expert Commentary: Although in vivo cross protection studies are more appropriate methods for vaccine matching and selection than in vitro neutralisation test or ELISA, in the face of an outbreak both in vivo and in vitro methods of vaccine matching are not easy, and time consuming. The FMDV capsid contains all the immunogenic epitopes, and therefore vaccine strain prediction models using both capsid sequence and serology data will likely replace existing tools in the future.

The temperature-sensitive mutants of Toxoplasma gondii and ocular toxoplasmosis.

PubMed

Lu, Fangli; Huang, Shiguang; Kasper, Lloyd H

2009-01-22

The risk of blindness caused by ocular toxoplasmosis supports efforts to improve our understanding for control of this disease. In this study, the involvement of CD8(+), CD4(+), B cell, and IL-10 gene in the immune response of primary ocular infection with the temperature-sensitive mutant (ts-4) of the RH Toxoplasma gondii strain, and in the protective immunity of ocular ts-4 vaccination and challenge with RH strain was investigated in murine models utilizing inbred C57BL/6 mice-deficient in CD4(+), CD8(+), B cells (microMT), or IL-10 gene. Compared to naive mice, all WT and mutant mice had different degree of ocular pathological changes after ts-4 ocular infection, in which both CD8 KO and IL-10 KO mice showed the most severe ocular lesions. Immunized by ts-4 intracameral (i.c.) inoculation, all mutant mice had partially decreased vaccine-induced resistance associated with increased ocular parasite burdens after RH strain challenge. A significant increase of the percentages of B cells and CD8(+) T cells in the draining lymph nodes were observed in WT and IL-10 KO mice after either infection or challenge. The levels of specific anti-toxoplasma IgG in both eye fluid and serum from all the mice were significantly increased after ts-4 i.c. immunization, except microMT mice. These results suggest that the avirulent ts-4 of T. gondii inoculated intracamerally can induce both ocular pathology and ocular protective immunity; CD4(+), CD8(+), B cell, and IL-10 gene are all necessary to the vaccine-induced resistance to ocular challenge by virulent RH strain, in which CD8(+) T cells are the most important component.

Applications of mutant yeast strains with low glycogen storage capability

NASA Technical Reports Server (NTRS)

Petersen, G. R.; Schubert, W. W.; Stokes, B. O.

1981-01-01

Several strains of Hansenula polymorpha were selected for possible low glycogen storage characteristics based on a selective I2 staining procedure. The levels of storage carbohydrates in the mutant strains were found to be 44-70% of the levels in the parent strain for cultures harvested in stationary phase. Similar differences generally were not found for cells harvested in exponential phase. Yeast strains deficient in glycogen storage capability are valuable in increasing the relative protein value of microbial biomass and also may provide significant cost savings in substrate utilization in fermentative processes.

The risk of aseptic meningitis associated with the Leningrad-Zagreb mumps vaccine strain following mass vaccination with measles-mumps-rubella vaccine, Rio Grande do Sul, Brazil, 1997.

PubMed

da Silveira, Claudio Marcos; Kmetzsch, Claudete Iris; Mohrdieck, Renate; Sperb, Alethea Fagundes; Prevots, D Rebecca

2002-10-01

Few data are available on the risk of aseptic meningitis following vaccination with the Leningrad-Zagreb (L-Z) strain of mumps vaccine. In 1997 the mumps vaccine was introduced into the state of Rio Grande do Sul in Brazil through mass vaccination with mumps-measles-rubella (MMR), targeting children aged 1-11 years. Five municipalities used exclusively MMR vaccine containing the L-Z strain of mumps. An outbreak of aseptic meningitis was observed shortly after the mass campaign. To estimate the risk of aseptic meningitis associated with this strain, we analysed vaccination and meningitis case surveillance data from the selected municipalities. A case of vaccine-associated aseptic meningitis was defined as one with a pleocytosis of 10-1,500 leukocytes/ml and occurring within 15-35 days after vaccine receipt. We estimated a risk of 2.9 cases per 10,000 doses of L-Z administered, equivalent to 1 case per 3,390 doses administered. The overall risk of aseptic meningitis following the campaign was increased 12.2-fold (95% CI: 6.0-24.7) compared with the same period in 1995-1996. Following the mass campaign, the incidence of mumps declined 93% during 1998-2000. Vaccination with the L-Z strain of mumps vaccine as part of a mass campaign was associated with a significantly increased risk of aseptic meningitis. Decisions about type of mumps vaccine and mumps vaccination strategies must consider vaccine safety issues in addition to other criteria.

Update of inactivated equine influenza vaccine strain in Japan

PubMed Central

GAMOH, Koichiro; NAKAMURA, Shigeyuki

2017-01-01

Japan established a vaccine selection system, in which a committee evaluates veterinary influenza vaccines to determine if the vaccine should be updated. In 2013, it was concluded that the present equine influenza vaccine strains did not have to be updated, but clade 2 (Fc2) viruses of the Florida sublineage should be included. We collected three Fc2 viruses as candidates and conducted comparative tests. Results indicated that A/equine/Carlow/2011 (H3N8) is not suitable, because of its unstable antigenic characteristics. A comparison between A/equine/Richmond/1/2007 (H3N8) (Richmond/07) and A/equine/Yokohama/aq13/2010 (H3N8) (Yokohama/10) in eggs showed that they shared equal growth properties. Immunogenicity test in mice showed that Yokohama/10 induced higher HI antibody titers than Richmond/07. Therefore, we concluded that Yokohama/10 was the most suitable strain. PMID:28163276

Assessment of a strain 19 brucellosis vaccination program in elk

USGS Publications Warehouse

Maichak, Eric J.; Scurlock, Brandon M.; Cross, Paul C.; Rogerson, Jared D.; Edwards, William H.; Wise, Benjamin; Smith, Scott G.; Kreeger, Terry J.

2017-01-01

Zoonotic diseases in wildlife present substantial challenges and risks to host populations, susceptible domestic livestock populations, and affected stakeholders. Brucellosis, a disease caused by the bacterium Brucella abortus, is endemic among elk (Cervus canadensis) attending winter feedgrounds and adjacent areas of western Wyoming, USA. To minimize transmission of brucellosis from elk to elk and elk to livestock, managers initiated a B. abortus strain 19 ballistic vaccination program in 1985. We used brucellosis prevalence (1971–2015) and reproductive outcome (2006–2015) data collected from female elk attending feedgrounds to assess efficacy of the strain 19 program while controlling for potentially confounding factors such as site and age. From our generalized linear models, we found that seroprevalence of brucellosis was 1) not lower following inception of vaccination; 2) not inversely associated with proportion of juveniles vaccinated over time; 3) not inversely associated with additional yearlings and adults vaccinated over time; and 4) associated more with feeding end-date than proportion of juveniles vaccinated. Using vaginal implant transmitters in adult females that were seropositive for brucellosis, we found little effect of vaccination coverage at reducing reproductive failures (i.e., abortion or stillbirth). Because we found limited support for efficacy of the strain 19 program, we support research to develop an oral vaccine and suggest that continuing other spatio-temporal management actions will be most effective to minimize transmission of brucellosis and reduce dependency of elk on supplemental winter feeding.

Protective immunity spectrum induced by immunization with a vaccine from the TBEV strain Sofjin.

PubMed

Chernokhaeva, L L; Rogova, Yu V; Vorovitch, M F; Romanova, L Iu; Kozlovskaya, L I; Maikova, G B; Kholodilov, I S; Karganova, G G

2016-04-29

Tick-borne encephalitis (TBE) circulates widely in the territory of Eurasia with up to 10,000 cases registered annually. The TBE virus (TBEV) includes three main subtypes: European, Siberian and Far-Eastern, and two new Asiatic variants, phylogenetically distant from the others. The inactivated antigen of European or Far-Eastern strains is used in commercial TBE vaccines. A set of 14 TBEV strains, isolated in 1937-2008, with different passage histories, representing all subtypes and variants, was used in this work. The chosen set covers almost all the TBE area. Sera of mice, immunized with the TBE vaccine Moscow, prepared from the TBEV strain Sofjin, were studied in a plaque neutralization test against the set of TBEV strains. The vaccine induced antibodies at a protective titer against all TBEV strains and Omsk hemorrhagic fever virus (OHFV) with Е protein amino acid distances of 0.008-0.069, but not against Powassan virus. We showed that after a course of two immunizations, factors such as the period between vaccinations (1-4 weeks), the challenging virus dose (30-1000 LD50) and terms of challenge (1-4 weeks after the last immunization) did not significantly affect the assessment of protective efficacy of the vaccine in vivo. The protective effect of the TBE vaccine Moscow against the set of TBEV strains and the OHFV was demonstrated in in vivo experiments. TBE vaccine Moscow did not protect mice against 10 LD50 of the Powassan virus. We showed that this range of Е protein amino acid distances between the vaccine strain and challenging virus do not have a decisive impact on the TBE vaccine protective effect in vitro and in vivo. Moreover, the TBE vaccine Moscow induces an immune response protective against a wide range of TBEV variants. Copyright © 2016 Elsevier Ltd. All rights reserved.

Inducamides A–C, Chlorinated Alkaloids from an RNA Polymerase Mutant Strain of Streptomyces sp.

PubMed Central

2015-01-01

Inducamides A–C (1–3), three new chlorinated alkaloids featuring an amide skeleton generated by a tryptophan fragment and a 6-methylsalicylic acid unit, were isolated from a chemically induced mutant strain of Streptomyces sp. with the inducamides only being produced in the mutant strain. Their structures, including stereochemistry, were determined by spectroscopic analysis, Marfey’s method, and CD spectroscopy. PMID:25338006

[Study on the neutralization capacity of different types of human measles virus vaccine and the epidemic strains].

PubMed

Feng, Yan; Lu, Yi-yu; Yan, Ju-ying; Jiang, Xiao-hui; Shi, Wen; Xu, Chang-ping; Li, Zhen

2007-11-01

To explore the neutralization capacities of different types of human serum to measles virus epidemic strains and vaccine strain. Neutralization antibody (NT) to Shanghai 191 and measles virus isolates in 2005 were tested using acute and convalescent serum samples from diagnosed measles patients, children serum samples collected before and after vaccination and serum samples of migrant residents, from 3 different regions. Additionally, animal immune serum referring to vaccine strain and 3 epidemic strains were prepared and used to undergo crossing neutralization test with corresponding strains mentioned-above. Antigenic ratios were calculated. GMT value of NT of after-immune serum to vaccine strains was 50.82,1.86 times higher than that to MVi/ZJ/05/7 (GMT was 27.35), whereas GMT value of convalescent serum to MVi/ZJ/05/7 (GMT was 386.95) was obviously higher than that to vaccine strain (GMT was 1:151.83),and GMT value of migrant residents' serum in 3 regions to MVi/ZJ/05/7 were 2.22-4.17 times lower than that to vaccine strain. Meanwhile,the antigenic ratios between MVi/ZJ/ 99/1, MVi/ZJ/04/1, MVi/ZJ/05/7 and vaccine strain were found to be 4.28,5.24 and 5.66 respectively. Additionally,low NT titers to vaccine strain were found in patients' acute sera and GMT value was over 1:4. There were obvious differences on neutralization antibody of different types of serum to measles vaccine strain and epidemic strains which indicating the antigenic diversity of epidemic strains had influenced the protective effectiveness of vaccine antibody to epidemic strains. It was of significance to carry on research projects on the antigenic diversity and effectiveness of measles vaccine.

Respiratory and oral vaccination improves protection conferred by the live vaccine strain against pneumonic tularemia in the rabbit model

PubMed Central

Stinson, Elizabeth; Smith, Le'Kneitah P.; Cole, Kelly Stefano; Barry, Eileen M.; Reed, Douglas S.

2016-01-01

Tularemia is a severe, zoonotic disease caused by a gram-negative bacterium, Francisella tularensis. We have previously shown that rabbits are a good model of human pneumonic tularemia when exposed to aerosols containing a virulent, type A strain, SCHU S4. We further demonstrated that the live vaccine strain (LVS), an attenuated type B strain, extended time to death when given by scarification. Oral or aerosol vaccination has been previously shown in humans to offer superior protection to parenteral vaccination against respiratory tularemia challenge. Both oral and aerosol vaccination with LVS were well tolerated in the rabbit with only minimal fever and no weight loss after inoculation. Plasma antibody titers against F. tularensis were higher in rabbits that were vaccinated by either oral or aerosol routes compared to scarification. Thirty days after vaccination, all rabbits were challenged with aerosolized SCHU S4. LVS given by scarification extended time to death compared to mock-vaccinated controls. One orally vaccinated rabbit did survive aerosol challenge, however, only aerosol vaccination extended time to death significantly compared to scarification. These results further demonstrate the utility of the rabbit model of pneumonic tularemia in replicating what has been reported in humans and macaques as well as demonstrating the utility of vaccination by oral and respiratory routes against an aerosol tularemia challenge. PMID:27511964

Respiratory and oral vaccination improves protection conferred by the live vaccine strain against pneumonic tularemia in the rabbit model.

PubMed

Stinson, Elizabeth; Smith, Le'Kneitah P; Cole, Kelly Stefano; Barry, Eileen M; Reed, Douglas S

2016-10-01

Tularemia is a severe, zoonotic disease caused by a gram-negative bacterium, Francisella tularensis We have previously shown that rabbits are a good model of human pneumonic tularemia when exposed to aerosols containing a virulent, type A strain, SCHU S4. We further demonstrated that the live vaccine strain (LVS), an attenuated type B strain, extended time to death when given by scarification. Oral or aerosol vaccination has been previously shown in humans to offer superior protection to parenteral vaccination against respiratory tularemia challenge. Both oral and aerosol vaccination with LVS were well tolerated in the rabbit with only minimal fever and no weight loss after inoculation. Plasma antibody titers against F. tularensis were higher in rabbits that were vaccinated by either oral or aerosol routes compared to scarification. Thirty days after vaccination, all rabbits were challenged with aerosolized SCHU S4. LVS given by scarification extended time to death compared to mock-vaccinated controls. One orally vaccinated rabbit did survive aerosol challenge, however, only aerosol vaccination extended time to death significantly compared to scarification. These results further demonstrate the utility of the rabbit model of pneumonic tularemia in replicating what has been reported in humans and macaques as well as demonstrating the utility of vaccination by oral and respiratory routes against an aerosol tularemia challenge. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

T-cell-mediated cross-strain protective immunity elicited by prime-boost vaccination with a live attenuated influenza vaccine.

PubMed

Li, Junwei; Arévalo, Maria T; Chen, Yanping; Chen, Shan; Zeng, Mingtao

2014-10-01

Antigenic drift and shift of influenza viruses require frequent reformulation of influenza vaccines. In addition, seasonal influenza vaccines are often mismatched to the epidemic influenza strains. This stresses the need for a universal influenza vaccine. BALB/c mice were vaccinated with the trivalent live attenuated (LAIV; FluMist) or inactivated (TIV; FluZone) influenza vaccines and challenged with PR8 (H1N1), FM/47 (H1N1), or HK/68 (H3N2) influenza virus. Cytokines and antibody responses were tested by ELISA. Furthermore, different LAIV dosages were applied in BALB/c mice. LAIV vaccinated mice were also depleted of T-cells and challenged with PR8 virus. LAIV induced significant protection against challenge with the non-vaccine strain PR8 influenza virus. Furthermore, protective immunity against PR8 was dose-dependent. Of note, interleukin 2 and interferon gamma cytokine secretion in the lung alveolar fluid were significantly elevated in mice vaccinated with LAIV. Moreover, T-cell depletion of LAIV vaccinated mice compromised protection, indicating that T-cell-mediated immunity is required. In contrast, passive transfer of sera from mice vaccinated with LAIV into naïve mice failed to protect against PR8 challenge. Neutralization assays in vitro confirmed that LAIV did not induce cross-strain neutralizing antibodies against PR8 virus. Finally, we showed that three doses of LAIV also provided protection against challenge with two additional heterologous viruses, FM/47 and HK/68. These results support the potential use of the LAIV as a universal influenza vaccine under a prime-boost vaccination regimen. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Experimental infection of horses with an attenuated Venezuelan equine encephalomyelitis vaccine (strain TC-83).

PubMed

Walton, T E; Alvarez, O; Buckwalter, R M; Johnson, K M

1972-05-01

Ten horses (Equus caballus) were vaccinated with strain TC-83 Venezuelan equine encephalomyelitis (VEE) virus vaccine. Febrile responses and leukopenia due to a reduction of lymphocytes and neutrophils were observed in all animals. Viremias were demonstrable in eight horses, with a maximum of 10(3.5) median tissue culture infectious dose units per ml of serum in two horses. Clinical illness with depression and anorexia were observed in five horses. Neutralizing (N), hemagglutination-inhibiting, and complement-fixing antibodies to the vaccine virus were demonstrable by 5, 6.5, and 7 days, respectively, after vaccination. Differential titrations of serum to six VEE strains revealed high titers of N antibody to vaccine virus, moderate titers to the epizootic Trinidad donkey no. 1 strain (VEE antigenic subtype I, variant A) from which TC-83 was derived, and low titers to two other epizootic strains (subtype I, variants B and C) in all horses at 1 month after vaccination; some animals responded with low levels of N antibody to the enzootic viruses (subtype I, variants D and E). Fourteen months after vaccination, six animals with detectable N antibody were challenged with MF-8 (subtype I, variant B), an epidemic-epizootic strain isolated in 1969 from a man in Honduras. All horses resisted challenge with the equine pathogenic strain of VEE. Marked increases of N antibody in most horses were demonstrable to some VEE strains when tested 1 month after challenge.

Experimental Infection of Horses with an Attenuated Venezuelan Equine Encephalomyelitis Vaccine (Strain TC-83)

PubMed Central

Walton, Thomas E.; Alvarez, Otto; Buckwalter, Ross M.; Johnson, Karl M.

1972-01-01

Ten horses (Equus caballus) were vaccinated with strain TC-83 Venezuelan equine encephalomyelitis (VEE) virus vaccine. Febrile responses and leukopenia due to a reduction of lymphocytes and neutrophils were observed in all animals. Viremias were demonstrable in eight horses, with a maximum of 103.5 median tissue culture infectious dose units per ml of serum in two horses. Clinical illness with depression and anorexia were observed in five horses. Neutralizing (N), hemagglutination-inhibiting, and complement-fixing antibodies to the vaccine virus were demonstrable by 5, 6.5, and 7 days, respectively, after vaccination. Differential titrations of serum to six VEE strains revealed high titers of N antibody to vaccine virus, moderate titers to the epizootic Trinidad donkey no. 1 strain (VEE antigenic subtype I, variant A) from which TC-83 was derived, and low titers to two other epizootic strains (subtype I, variants B and C) in all horses at 1 month after vaccination; some animals responded with low levels of N antibody to the enzootic viruses (subtype I, variants D and E). Fourteen months after vaccination, six animals with detectable N antibody were challenged with MF-8 (subtype I, variant B), an epidemic-epizootic strain isolated in 1969 from a man in Honduras. All horses resisted challenge with the equine pathogenic strain of VEE. Marked increases of N antibody in most horses were demonstrable to some VEE strains when tested 1 month after challenge. PMID:4637604

Egg quality in laying hens exposed to Mycoplasma gallisepticum F-strain attenuated vaccine.

PubMed

Machado, L D S; Santos, F F D; Togashi, C K; Abreu, D L D C; Pimentel, J C; Sesti, L; Pereira, V L D A; Nascimento, E R D

2017-04-01

Mycoplasma gallisepticum causes coughing, ocular and nasal discharge, reduction in feed intake, lower and uneven growth, decline in egg production and quality, and increase in mortality. Among the attenuated vaccination strains, MGF can reduce clinical signs and lesions in layer hens, stimulate immune responses of cellular and humoral basis, act as an instrument of competitive exclusion in relation to field strains, and reduce the use of antimicrobials. This study aimed to investigate the effects of attenuated MG F-strain vaccination on egg quality in 3 groups of 30 hens each, being one control and 2 vaccinated. Vaccination was applied by ocular route at 8 and 12 wk of age. Comparisons were made among unvaccinated hens; vaccinated at 8 wk of age; and vaccinated at 8 and 12 wk of age. There were no statistical differences in eggshell thickness and weight among groups. Eggs from twice vaccinated birds yielded a Haugh unit significantly lower than the other groups without affecting egg classification. There was no significant difference in ELISA results between the vaccinated groups. © 2016 Poultry Science Association Inc.

Role of Sterylglucosidase 1 (Sgl1) on the pathogenicity of Cryptococcus neoformans: potential applications for vaccine development

PubMed Central

Rella, Antonella; Mor, Visesato; Farnoud, Amir M.; Singh, Ashutosh; Shamseddine, Achraf A.; Ivanova, Elitza; Carpino, Nicholas; Montagna, Maria T.; Luberto, Chiara; Del Poeta, Maurizio

2015-01-01

Cryptococcosis caused by Cryptococcus neoformans and Cryptococcus gattii affects a large population and is a cause of significant morbidity and mortality. Despite its public health burden, there are currently no vaccines against cryptococcosis and new strategies against such infections are needed. In this study, we demonstrate that C. neoformans has the biochemical ability to metabolize sterylglucosides (SGs), a class of immunomodulatory glycolipids. Genetic manipulations that eliminate cryptococccal sterylglucosidase lead to the accumulation of SGs and generate a mutant strain (Δsgl1) that is non-pathogenic in the mouse models of cryptococcosis. Interestingly, this mutant strain acts as a vaccine strain and protects mice against cryptococcosis following infection with C. neoformans or C. gattii. The immunity induced by the Δsgl1 strain is not CD4+ T-cells dependent. Immunocompromised mice, which lack CD4+ T-cells, are able to control the infection by Δsgl1 and acquire immunity against the challenge by wild-type C. neoformans following vaccination with the Δsgl1 strain. These findings are particularly important in the context of HIV/AIDS immune deficiency and suggest that the Δsgl1 strain might provide a potential vaccination strategy against cryptococcosis. PMID:26322039

Role of Sterylglucosidase 1 (Sgl1) on the pathogenicity of Cryptococcus neoformans: potential applications for vaccine development.

PubMed

Rella, Antonella; Mor, Visesato; Farnoud, Amir M; Singh, Ashutosh; Shamseddine, Achraf A; Ivanova, Elitza; Carpino, Nicholas; Montagna, Maria T; Luberto, Chiara; Del Poeta, Maurizio

2015-01-01

Cryptococcosis caused by Cryptococcus neoformans and Cryptococcus gattii affects a large population and is a cause of significant morbidity and mortality. Despite its public health burden, there are currently no vaccines against cryptococcosis and new strategies against such infections are needed. In this study, we demonstrate that C. neoformans has the biochemical ability to metabolize sterylglucosides (SGs), a class of immunomodulatory glycolipids. Genetic manipulations that eliminate cryptococccal sterylglucosidase lead to the accumulation of SGs and generate a mutant strain (Δsgl1) that is non-pathogenic in the mouse models of cryptococcosis. Interestingly, this mutant strain acts as a vaccine strain and protects mice against cryptococcosis following infection with C. neoformans or C. gattii. The immunity induced by the Δsgl1 strain is not CD4(+) T-cells dependent. Immunocompromised mice, which lack CD4(+) T-cells, are able to control the infection by Δsgl1 and acquire immunity against the challenge by wild-type C. neoformans following vaccination with the Δsgl1 strain. These findings are particularly important in the context of HIV/AIDS immune deficiency and suggest that the Δsgl1 strain might provide a potential vaccination strategy against cryptococcosis.

The Breeding of a Pigment Mutant Strain of Steroid Hydroxylation Aspergillus Flavus by Low Energy Ion Implantation

NASA Astrophysics Data System (ADS)

Ye, Hui; Ma, Jingming; Feng, Chun; Cheng, Ying; Zhu, Suwen; Cheng, Beijiu

2009-02-01

In the process of the fermentation of steroid C11α-hydroxylgenation strain Aspergillus flavus AF-ANo208, a red pigment is derived, which will affect the isolation and purification of the target product. Low energy ion beam implantation is a new tool for breeding excellent mutant strains. In this study, the ion beam implantation experiments were performed by infusing two different ions: argon ion (Ar+) and nitrogen ion (N+). The results showed that the optimal ion implantation was N+ with an optimum dose of 2.08 × 1015 ions/cm2, with which the mutant strain AF-ANm16 that produced no red pigment was obtained. The strain had high genetic stability and kept the strong capacity of C11α-hydroxylgenation, which could be utilized in industrial fermentation. The differences between the original strain and the mutant strain at a molecular level were analyzed by randomly amplified polymorphic DNA (RAPD). The results indicated that the frequency of variation was 7.00%, which would establish the basis of application investigation into the breeding of pigment mutant strains by low energy ion implantation.

Complex adenovirus-vectored vaccine protects guinea pigs from three strains of Marburg virus challenges.

PubMed

Wang, Danher; Hevey, Michael; Juompan, Laure Y; Trubey, Charles M; Raja, Nicholas U; Deitz, Stephen B; Woraratanadharm, Jan; Luo, Min; Yu, Hong; Swain, Benjamin M; Moore, Kevin M; Dong, John Y

2006-09-30

The Marburg virus (MARV), an African filovirus closely related to the Ebola virus, causes a deadly hemorrhagic fever in humans, with up to 90% mortality. Currently, treatment of disease is only supportive, and no vaccines are available to prevent spread of MARV infections. In order to address this need, we have developed and characterized a novel recombinant vaccine that utilizes a single complex adenovirus-vectored vaccine (cAdVax) to overexpress a MARV glycoprotein (GP) fusion protein derived from the Musoke and Ci67 strains of MARV. Vaccination with the cAdVaxM(fus) vaccine led to efficient production of MARV-specific antibodies in both mice and guinea pigs. Significantly, guinea pigs vaccinated with at least 5 x 10(7) pfu of cAdVaxM(fus) vaccine were 100% protected against lethal challenges by the Musoke, Ci67 and Ravn strains of MARV, making it a vaccine with trivalent protective efficacy. Therefore, the cAdVaxM(fus) vaccine serves as a promising vaccine candidate to prevent and contain multi-strain infections by MARV.

Complex adenovirus-vectored vaccine protects guinea pigs from three strains of Marburg virus challenges

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang Danher; Hevey, Michael; Juompan, Laure Y.

2006-09-30

The Marburg virus (MARV), an African filovirus closely related to the Ebola virus, causes a deadly hemorrhagic fever in humans, with up to 90% mortality. Currently, treatment of disease is only supportive, and no vaccines are available to prevent spread of MARV infections. In order to address this need, we have developed and characterized a novel recombinant vaccine that utilizes a single complex adenovirus-vectored vaccine (cAdVax) to overexpress a MARV glycoprotein (GP) fusion protein derived from the Musoke and Ci67 strains of MARV. Vaccination with the cAdVaxM(fus) vaccine led to efficient production of MARV-specific antibodies in both mice and guineamore » pigs. Significantly, guinea pigs vaccinated with at least 5 x 10{sup 7} pfu of cAdVaxM(fus) vaccine were 100% protected against lethal challenges by the Musoke, Ci67 and Ravn strains of MARV, making it a vaccine with trivalent protective efficacy. Therefore, the cAdVaxM(fus) vaccine serves as a promising vaccine candidate to prevent and contain multi-strain infections by MARV.« less

Association of deficiency in antibody response to vaccine and heterogeneity of Ehrlichia risticii strains with Potomac horse fever vaccine failure in horses.

PubMed

Dutta, S K; Vemulapalli, R; Biswas, B

1998-02-01

Ehrlichia risticii is the causative agent of Potomac horse fever (PHF), which continues to be an important disease of horses. Commercial inactivated whole-cell vaccines are regularly used for immunization of horses against the disease. However, PHF is occurring in large numbers of horses in spite of vaccination. In a limited study, 43 confirmed cases of PHF occurred between the 1994 and 1996 seasons; of these, 38 (89%) were in horses that had been vaccinated for the respective season, thereby clearly indicating vaccine failure. A field study of horses vaccinated with two PHF vaccines indicated a poor antibody response, as determined by immunofluorescence assay (IFA) titers. In a majority of horses, the final antibody titer ranged between 40 and 1,280, in spite of repeated vaccinations. None of the vaccinated horses developed in vitro neutralizing antibody in their sera. Similarly, one horse experimentally vaccinated three times with one of the vaccines showed a poor antibody response, with final IFA titers between 80 and 160. The horse did not develop in vitro neutralizing antibody or antibody against the 50/85-kDa strain-specific antigen (SSA), which is the protective antigen of the original strain, 25-D, and the variant strain of our laboratory, strain 90-12. Upon challenge infection with the 90-12 strain, the horse showed clinical signs of the disease. The horse developed neutralizing antibody and antibody to the 50/85-kDa SSA following the infection. Studies of the new E. risticii isolates from the field cases indicated that they were heterogeneous among themselves and showed differences from the 25-D and 90-12 strains as determined by IFA reactivity pattern, DNA amplification finger printing profile, and in vitro neutralization activity. Most importantly, the molecular sizes of the SSA of these isolates varied, ranging from 48 to 85 kDa. These studies suggest that the deficiency in the antibody response to the PHF vaccines and the heterogeneity of E. risticii

Association of Deficiency in Antibody Response to Vaccine and Heterogeneity of Ehrlichia risticii Strains with Potomac Horse Fever Vaccine Failure in Horses

PubMed Central

Dutta, Sukanta K.; Vemulapalli, Ramesh; Biswas, Biswajit

1998-01-01

Ehrlichia risticii is the causative agent of Potomac horse fever (PHF), which continues to be an important disease of horses. Commercial inactivated whole-cell vaccines are regularly used for immunization of horses against the disease. However, PHF is occurring in large numbers of horses in spite of vaccination. In a limited study, 43 confirmed cases of PHF occurred between the 1994 and 1996 seasons; of these, 38 (89%) were in horses that had been vaccinated for the respective season, thereby clearly indicating vaccine failure. A field study of horses vaccinated with two PHF vaccines indicated a poor antibody response, as determined by immunofluorescence assay (IFA) titers. In a majority of horses, the final antibody titer ranged between 40 and 1,280, in spite of repeated vaccinations. None of the vaccinated horses developed in vitro neutralizing antibody in their sera. Similarly, one horse experimentally vaccinated three times with one of the vaccines showed a poor antibody response, with final IFA titers between 80 and 160. The horse did not develop in vitro neutralizing antibody or antibody against the 50/85-kDa strain-specific antigen (SSA), which is the protective antigen of the original strain, 25-D, and the variant strain of our laboratory, strain 90-12. Upon challenge infection with the 90-12 strain, the horse showed clinical signs of the disease. The horse developed neutralizing antibody and antibody to the 50/85-kDa SSA following the infection. Studies of the new E. risticii isolates from the field cases indicated that they were heterogeneous among themselves and showed differences from the 25-D and 90-12 strains as determined by IFA reactivity pattern, DNA amplification finger printing profile, and in vitro neutralization activity. Most importantly, the molecular sizes of the SSA of these isolates varied, ranging from 48 to 85 kDa. These studies suggest that the deficiency in the antibody response to the PHF vaccines and the heterogeneity of E. risticii

Role of vaccination-induced immunity and antigenic distance in the transmission dynamics of highly pathogenic avian influenza H5N1

PubMed Central

Rousou, Xanthoula; Kalthoff, Donata; Beer, Martin

2016-01-01

Highly pathogenic avian influenza (HPAI) H5N1 epidemics in poultry cause huge economic losses as well as sporadic human morbidity and mortality. Vaccination in poultry has often been reported as being ineffective in preventing transmission and as a potential driving force in the selection of immune escape mutants. We conducted transmission experiments to evaluate the transmission dynamics of HPAI H5N1 strains in chickens vaccinated with high and low doses of immune escape mutants we have previously selected, and analysed the data using mathematical models. Remarkably, we demonstrate that the effect of antigenic distances between the vaccine and challenge strains used in this study is too small to influence the transmission dynamics of the strains used. This is because the effect of a sufficient vaccine dose on antibody levels against the challenge viruses is large enough to compensate for any decrease in antibody titres due to antigenic differences between vaccine and challenge strains. Our results show that at least under experimental conditions, vaccination will remain effective even after antigenic changes as may be caused by the initial selection in vaccinated birds. PMID:26763336

Induction of pure and sectored mutant clones in excision-proficient and deficient strains of yeast.

PubMed

Eckardt, F; Haynes, R H

1977-06-01

We have found that UV-induced mutation frequency in a forward non-selective assay system (scoring white adex ade2 double auxotroph mutants among the red pigmented ade2 clones) increases linearly with dose up to a maximum frequency of about 3 X 10(-3) mutants per survivor and then declines in both RAD wild-type and rad2 excision deficient strains of Saccharomyces cerevisiae. Mutation frequencies of the RAD and the rad2 strains plotted against survival are nearly identical over the entire survival range. On this basis we conclude that unexcised pyrimidine dimers are the predominant type of pre-mutational lesions in both strains. In the RAD wild-type strain pure mutant clones outnumber sectors in a 10:1 ratio at all doses used; in rad2 this ratio varies from 1:1 at low doses up to 10:1 at high doses. As others have concluded for wild-type strains we find also in the rad2 strain that pure clone formation cannot be accounted for quantitatively by lethal sectoring events alone. We conclude that heteroduplex repair is a crucial step in pure mutant clone formation and we examine the plausibility of certain macromolecular mechanisms according to which heteroduplex repair may be coupled with replication, repair and sister strand exchange in yeast mutagenesis.

Genetic and physiological characterization of a Rhizobium etli mutant strain unable to synthesize poly-beta-hydroxybutyrate.

PubMed Central

Cevallos, M A; Encarnación, S; Leija, A; Mora, Y; Mora, J

1996-01-01

Rhizobium etli accumulates poly-beta-hydroxybutyrate (PHB) in symbiosis and in free life. PHB is a reserve material that serves as a carbon and/or electron sink when optimal growth conditions are not met. It has been suggested that in symbiosis PHB can prolong nitrogen fixation until the last stages of seed development, but experiments to test this proposition have not been done until now. To address these questions in a direct way, we constructed an R. etli PHB-negative mutant by the insertion of an Omega-Km interposon within the PHB synthase structural gene (phaC). The identification and sequence of the R. etli phaC gene are also reported here. Physiological studies showed that the PHB-negative mutant strain was unable to synthesize PHB and excreted more lactate, acetate, pyruvate, beta-hydroxybutyrate, fumarate, and malate than the wild-type strain. The NAD+/NADH ratio in the mutant strain was lower than that in the parent strain. The oxidative capacity of the PHB-negative mutant was reduced. Accordingly, the ability to grow in minimal medium supplemented with glucose or pyruvate was severely diminished in the mutant strain. We propose that in free life PHB synthesis sequesters reductive power, allowing the tricarboxylic acid cycle to proceed under conditions in which oxygen is a limiting factor. In symbiosis with Phaseolus vulgaris, the PHB-negative mutant induced nodules that prolonged the capacity to fix nitrogen. PMID:8626293

Immunization with a Recombinant, Pseudomonas fluorescens-Expressed, Mutant Form of Bacillus anthracis-Derived Protective Antigen Protects Rabbits from Anthrax Infection.

PubMed

Reed, Matthew D; Wilder, Julie A; Mega, William M; Hutt, Julie A; Kuehl, Philip J; Valderas, Michelle W; Chew, Lawrence L; Liang, Bertrand C; Squires, Charles H

2015-01-01

Protective antigen (PA), one of the components of the anthrax toxin, is the major component of human anthrax vaccine (Biothrax). Human anthrax vaccines approved in the United States and Europe consist of an alum-adsorbed or precipitated (respectively) supernatant material derived from cultures of toxigenic, non-encapsulated strains of Bacillus anthracis. Approved vaccination schedules in humans with either of these vaccines requires several booster shots and occasionally causes adverse injection site reactions. Mutant derivatives of the protective antigen that will not form the anthrax toxins have been described. We have cloned and expressed both mutant (PA SNKE167-ΔFF-315-E308D) and native PA molecules recombinantly and purified them. In this study, both the mutant and native PA molecules, formulated with alum (Alhydrogel), elicited high titers of anthrax toxin neutralizing anti-PA antibodies in New Zealand White rabbits. Both mutant and native PA vaccine preparations protected rabbits from lethal, aerosolized, B. anthracis spore challenge subsequent to two immunizations at doses of less than 1 μg.

Influenza immunization elicits antibodies specific for an egg-adapted vaccine strain.

PubMed

Raymond, Donald D; Stewart, Shaun M; Lee, Jiwon; Ferdman, Jack; Bajic, Goran; Do, Khoi T; Ernandes, Michael J; Suphaphiphat, Pirada; Settembre, Ethan C; Dormitzer, Philip R; Del Giudice, Giuseppe; Finco, Oretta; Kang, Tae Hyun; Ippolito, Gregory C; Georgiou, George; Kepler, Thomas B; Haynes, Barton F; Moody, M Anthony; Liao, Hua-Xin; Schmidt, Aaron G; Harrison, Stephen C

2016-12-01

For broad protection against infection by viruses such as influenza or HIV, vaccines should elicit antibodies that bind conserved viral epitopes, such as the receptor-binding site (RBS). RBS-directed antibodies have been described for both HIV and influenza virus, and the design of immunogens to elicit them is a goal of vaccine research in both fields. Residues in the RBS of influenza virus hemagglutinin (HA) determine a preference for the avian or human receptor, α-2,3-linked sialic acid and α-2,6-linked sialic acid, respectively. Transmission of an avian-origin virus between humans generally requires one or more mutations in the sequences encoding the influenza virus RBS to change the preferred receptor from avian to human, but passage of a human-derived vaccine candidate in chicken eggs can select for reversion to avian receptor preference. For example, the X-181 strain of the 2009 new pandemic H1N1 influenza virus, derived from the A/California/07/2009 isolate and used in essentially all vaccines since 2009, has arginine at position 226, a residue known to confer preference for an α-2,3 linkage in H1 subtype viruses; the wild-type A/California/07/2009 isolate, like most circulating human H1N1 viruses, has glutamine at position 226. We describe, from three different individuals, RBS-directed antibodies that recognize the avian-adapted H1 strain in current influenza vaccines but not the circulating new pandemic 2009 virus; Arg226 in the vaccine-strain RBS accounts for the restriction. The polyclonal sera of the three donors also reflect this preference. Therefore, when vaccines produced from strains that are never passaged in avian cells become widely available, they may prove more capable of eliciting RBS-directed, broadly neutralizing antibodies than those produced from egg-adapted viruses, extending the established benefits of current seasonal influenza immunizations.

Assessment of attenuated Salmonella vaccine strains in controlling experimental Salmonella Typhimurium infection in chickens

PubMed Central

Pei, Yanlong; Parreira, Valeria R.; Roland, Kenneth L.; Curtiss, Roy; Prescott, John F.

2014-01-01

Salmonella hold considerable promise as vaccine delivery vectors for heterologous antigens in chickens. Such vaccines have the potential additional benefit of also controlling Salmonella infection in immunized birds. As a way of selecting attenuated strains with optimal immunogenic potential as antigen delivery vectors, this study screened 20 novel Salmonella Typhimurium vaccine strains, differing in mutations associated with delayed antigen synthesis and delayed attenuation, for their efficacy in controlling colonization by virulent Salmonella Typhimurium, as well as for their persistence in the intestine and the spleen. Marked differences were observed between strains in these characteristics, which provide the basis for selection for further study as vaccine vectors. PMID:24396177

Assessment of attenuated Salmonella vaccine strains in controlling experimental Salmonella Typhimurium infection in chickens.

PubMed

Pei, Yanlong; Parreira, Valeria R; Roland, Kenneth L; Curtiss, Roy; Prescott, John F

2014-01-01

Salmonella hold considerable promise as vaccine delivery vectors for heterologous antigens in chickens. Such vaccines have the potential additional benefit of also controlling Salmonella infection in immunized birds. As a way of selecting attenuated strains with optimal immunogenic potential as antigen delivery vectors, this study screened 20 novel Salmonella Typhimurium vaccine strains, differing in mutations associated with delayed antigen synthesis and delayed attenuation, for their efficacy in controlling colonization by virulent Salmonella Typhimurium, as well as for their persistence in the intestine and the spleen. Marked differences were observed between strains in these characteristics, which provide the basis for selection for further study as vaccine vectors.

Strain-specific protective immunity following vaccination against experimental Trypanosoma cruzi infection.

PubMed

Haolla, Filipe A; Claser, Carla; de Alencar, Bruna C G; Tzelepis, Fanny; de Vasconcelos, José Ronnie; de Oliveira, Gabriel; Silvério, Jaline C; Machado, Alexandre V; Lannes-Vieira, Joseli; Bruna-Romero, Oscar; Gazzinelli, Ricardo T; dos Santos, Ricardo Ribeiro; Soares, Milena B P; Rodrigues, Mauricio M

2009-09-18

Immunisation with Amastigote Surface Protein 2 (asp-2) and trans-sialidase (ts) genes induces protective immunity in highly susceptible A/Sn mice, against infection with parasites of the Y strain of Trypanosoma cruzi. Based on immunological and biological strain variations in T. cruzi parasites, our goal was to validate our vaccination results using different parasite strains. Due to the importance of the CD8(+) T cells in protective immunity, we initially determined which strains expressed the immunodominant H-2K(k)-restricted epitope TEWETGQI. We tested eight strains, four of which elicited immune responses to this epitope (Y, G, Colombian and Colombia). We selected the Colombian and Colombia strains for our studies. A/Sn mice were immunised with different regimens using both T. cruzi genes (asp-2 and ts) simultaneously and subsequently challenged with blood trypomastigotes. Immune responses before the challenge were confirmed by the presence of specific antibodies and peptide-specific T cells. Genetic vaccination did not confer protective immunity against acute infection with a lethal dose of the Colombian strain. In contrast, we observed a drastic reduction in parasitemia and a significant increase in survival, following challenge with an otherwise lethal dose of the Colombia strain. In many surviving animals with late-stage chronic infection, we observed alterations in the heart's electrical conductivity, compared to naive mice. In summary, we concluded that immunity against T. cruzi antigens, similar to viruses and bacteria, may be strain-specific and have a negative impact on vaccine development.

Photosynthetic Electron Transport Chain of Chlamydomonas reinhardi VI. Electron Transport in Mutant Strains Lacking Either Cytochrome 553 or Plastocyanin 1

PubMed Central

Gorman, Donald S.; Levine, R. P.

1966-01-01

A mutant strain of Chlamydomonas reinhardi, ac-206, lacks cytochrome 553, at least in an active and detectable form. Chloroplast fragments of this mutant strain are inactive in the photoreduction of NADP when the source of electrons is water, but they are active when the electron source is 2,6-dichlorophenolindophenol and ascorbate. The addition of either cytochrome 553 or plastocyanin, obtained from the wild-type strain, has no effect upon the photosynthetic activities of the mutant strain. Cells of the mutant strain lack both the soluble and insoluble forms of cytochrome 553, but they possess the mitochondrial type cytochrome c. Thus, the loss of cytochrome 553 appears to be specific. Another mutant strain, ac-208, lacks plastocyanin, or possesses it in an inactive and undetectable form. Chloroplast fragments of ac-208 are inactive in the photoreduction of NADP with either water or 2,6-dichlorophenolindophenol and ascorbate as electron donors. However, these reactions are restored upon the addition of plastocyanin. The addition of cytochrome 553 has no effect. The measurement of light-induced absorbance changes with ac-208 reveal that, in the absence of plastocyanin, light fails to sensitize the oxidation of cytochrome 553, but it will sensitize its reduction. However, the addition of plastocyanin restores the light-induced cytochrome oxidation. A third mutant strain, ac-208 (sup.) carries a suppressor mutation that partially restores the wild phenotype. This mutant strain appears to possess a plastocyanin that is less stable than that of the wild-type strain. The observations with the mutant strains are discussed in terms of the sequence of electron transport System II → cytochrome 553 → plastocyanin → System I. PMID:16656453

Herpes Zoster Caused by Vaccine-Strain Varicella Zoster Virus in an Immunocompetent Recipient of Zoster Vaccine

PubMed Central

Tseng, Hung Fu; Schmid, D. Scott; Harpaz, Rafael; LaRussa, Philip; Jensen, Nancy J.; Rivailler, Pierre; Radford, Kay; Folster, Jennifer; Jacobsen, Steven J.

2014-01-01

We report the first laboratory-documented case of herpes zoster caused by the attenuated varicella zoster virus (VZV) contained in Zostavax in a 68-year-old immunocompetent adult with strong evidence of prior wild-type VZV infection. The complete genome sequence of the isolate revealed that the strain carried 15 of 42 (36%) recognized varicella vaccine–associated single-nucleotide polymorphisms, including all 5 of the fixed vaccine markers present in nearly all of the strains in the vaccine. The case of herpes zoster was relatively mild and resolved without complications. PMID:24470276

Vaccine-strain herpes zoster found in the trigeminal nerve area in a healthy child: A case report.

PubMed

Iwasaki, Sayaka; Motokura, Kouji; Honda, Yoshitaka; Mikami, Masamitsu; Hata, Daisuke; Hata, Atsuko

2016-12-01

A previously healthy 2-year-old girl, vaccinated for varicella at 17 months, was admitted because of left-sided facial herpes zoster caused by vaccine-strain varicella-zoster virus (VZV). She recovered fully with no complication after intravenous treatment using acyclovir. Earlier reports have described that herpes zoster (HZ) rashes caused by vaccine-strain VZV tend to occur on the dermis corresponding to the skin area where the varicella vaccine was received. However, rashes appeared on this girl only in the trigeminal nerve area, which is unrelated to the vaccinated site. Results underscore the importance of distinguishing vaccine-strain VZV from wild-type VZV whenever encountering HZ cases after vaccination, even in immunocompetent children, irrespective of the skin lesion site. Monitoring vaccine-strain HZ incidence rates is expected to elucidate many aspects of varicella vaccine safety. Copyright © 2016 Elsevier B.V. All rights reserved.

Protective immune response of chickens to oral vaccination with thermostable live Fowlpox virus vaccine (strain TPV-1) coated on oiled rice.

PubMed

Wambura, Philemon N; Godfrey, S K

2010-03-01

The objective of the present study was to develop and evaluate a local vaccine (strain TPV-1) against Fowl pox (FP) in chickens. Two separate groups of chickens were vaccinated with FP vaccine through oral (coated on oiled rice) and wing web stab routes, respectively. The results showed that the haemagglutination-inhibition (HI) antibody titres in both vaccinated groups were comparable and significantly higher (P < 0.05) than the control chickens. It was further revealed that 14 days after vaccination HI GMT of > or =2 log(2) was recorded in chickens vaccinated by oral and wing web stab routes whereas 35 days after vaccination the HI antibody titres reached 5.6 log(2) and 6.3 log(2), respectively. Moreover, in both groups the birds showed 100% protection against challenge virus at 35 days after vaccination. The findings from the present study have shown that oral route is equally effective as wing web stab route for vaccination of chickens against FP. However, the oral route can be used in mass vaccination of birds thus avoid catching individual birds for vaccination. It was noteworthy that strain TPV-1 virus could be propagated by a simple allantoic cavity inoculation and harvesting of allantoic fluid where it survived exposure at 57 degrees C for 2 hours. If the oral vaccination technique is optimized it may be used in controlling FP in scavenging and feral chickens. In conclusion, the present study has shown that FP vaccine (strain TPV-1) was safe, thermostable, immunogenic and efficacious in vaccinated chickens.

Reverse spillover of avian viral vaccine strains from domesticated poultry to wild birds.

PubMed

Rohaim, M A; El Naggar, R F; Helal, A M; Hussein, H A; Munir, Muhammad

2017-06-16

Transmission of viruses from the commercial poultry to wild birds is an emerging paradigm of livestock-wildlife interface. Here, we report the identification and isolation of vaccine strains of avian paramyxovirus serotype 1 (APMV1) and avian coronaviruses (ACoV) from different wild bird species across eight Egyptian governorates between January 2014 and December 2015. Surveillance of avian respiratory viruses in free-ranging wild birds (n=297) identified three species that harboured or excreted APMV1 and ACoVs. Genetic characterization and phylogenetic analysis of recovered viruses revealed a close association with the most widely utilized vaccine strains in the country. These results highlight the potential spillover of vaccine-viruses probably due to extensive use of live-attenuated vaccines in the commercial poultry, and close interaction between domesticated and wild bird populations. Further exploring the full spectrum of vaccine-derived viral vaccine strains in wild birds might help to assess the emergence of future wild-birds origin viruses. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Persistence and spreading of field and vaccine strains of infectious laryngotracheitis virus (ILTV) in vaccinated and unvaccinated geographic regions, in Brazil.

PubMed

Chacón, Jorge Luis; Núñez, Luis Fabian Naranjo; Vejarano, Maria Pilar; Parra, Silvana Hipatia Santander; Astolfi-Ferreira, Claudete Serrano; Ferreira, Antonio José Piantino

2015-08-01

Infectious laryngotracheitis (ILT) is a highly infectious respiratory disease that causes morbidity and mortality in commercial chickens. Despite the use of attenuated vaccines, ILT outbreaks have been described in broiler and long-lived birds. Molecular approaches, including polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and DNA sequencing, are used to characterize ILT viruses (ILTVs) detected in vaccinated and unvaccinated geographical regions. As part of an ILT control program implemented in a region of commercial layer production, samples of conjunctiva, trachea, and trigeminal ganglia were collected from chickens in a vaccinated and quarantined region over a period of 8 years after initiation of vaccination. To determine the origin of new ILT outbreaks in unvaccinated regions, samples collected from ill chickens were also analyzed. Chicken embryo origin (CEO) vaccine viruses and the Bastos field strain were detected circulating in healthy chickens in the vaccinated region. CEO strains and field viruses molecularly related to the Bastos strain were also detected outside of the quarantined region in chickens showing clinical signs of ILT. This study reveals the persistence and circulation of a wild field strain, despite the intensive use of tissue culture origin (TCO) and CEO vaccines in a quarantined region. Spreading of CEO viruses to unvaccinated regions and the capacity of this virus to establish latent infections and cause severe outbreaks were also observed.

Inactivation of SAM-methyltransferase is the mechanism of attenuation of a historic louse borne typhus vaccine strain.

PubMed

Liu, Yan; Wu, Bin; Weinstock, George; Walker, David H; Yu, Xue-Jie

2014-01-01

Louse borne typhus (also called epidemic typhus) was one of man's major scourges, and epidemics of the disease can be reignited when social, economic, or political systems are disrupted. The fear of a bioterrorist attack using the etiologic agent of typhus, Rickettsia prowazekii, was a reality. An attenuated typhus vaccine, R. prowazekii Madrid E strain, was observed to revert to virulence as demonstrated by isolation of the virulent revertant Evir strain from animals which were inoculated with Madrid E strain. The mechanism of the mutation in R. prowazekii that affects the virulence of the vaccine was not known. We sequenced the genome of the virulent revertant Evir strain and compared its genome sequence with the genome sequences of its parental strain, Madrid E. We found that only a single nucleotide in the entire genome was different between the vaccine strain Madrid E and its virulent revertant strain Evir. The mutation is a single nucleotide insertion in the methyltransferase gene (also known as PR028) in the vaccine strain that inactivated the gene. We also confirmed that the vaccine strain E did not cause fever in guinea pigs and the virulent revertant strain Evir caused fever in guinea pigs. We concluded that a single nucleotide insertion in the methyltransferase gene of R. prowazekii attenuated the R. prowazekii vaccine strain E. This suggested that an irreversible insertion or deletion mutation in the methyl transferase gene of R. prowazekii is required for Madrid E to be considered a safe vaccine.

Duplex PCR for differentiation of the vaccine strain Brucella suis S2 and B. suis biovar 1 from other strains of Brucella spp.

PubMed

Nan, Wenlong; Tan, Pengfei; Wang, Yong; Xu, Zouliang; Mao, Kairong; Peng, Daxin; Chen, Yiping

2014-09-01

Immunisation with attenuated Brucella spp. vaccines prevents brucellosis, but may also interfere with diagnosis. In this study, a duplex PCR was developed to distinguish Brucella suis vaccine strain S2 from field strains of B. suis biovar 1 and other Brucella spp. The PCR detected 60 fg genomic DNA of B. suis S2 or biovar 1 field strains and was able to distinguish B. suis S2 and wild-type strains of B. suis biovar 1 among 76 field isolates representing all the common species and biovars, as well as four vaccine strains, of Brucella. Copyright © 2014 Elsevier Ltd. All rights reserved.

Construction of upp deletion mutant strains of Lactobacillus casei and Lactococcus lactis based on counterselective system using temperature-sensitive plasmid.

PubMed

Song, Li; Cui, Hongyu; Tang, Lijie; Qiao, Xinyuan; Liu, Min; Jiang, Yanping; Cui, Wen; Li, Yijing

2014-07-01

Integration plasmids are often used in constructing chromosomal mutations, as it enables the alternation of genes at any location by integration or replacement. Food-grade integration vectors can integrate into the host genome without introducing any selectable markers or residual bases, and the recombination often happens in non-coding region. In this study we used the temperature-sensitive pWV01 replicon to construct 2 chloramphenicol-resistant integration plasmids (pGBHC32-upp) containing the uracil phosphoribosyl transferase (upp) gene as a counterselective marker for Lactobacillus casei (L. casei) ATCC393 and Lactococcus lactis (L. lactis) MG1363. We then ligated the designed homologous arms to the pGBHC32-upp plasmids to allow their integration to the bacterial chromosome, and selected upp deletion mutants of L. casei ATCC393 and L. lactis MG1363 in the presence of 5-fluorouracil (5-FU). Analysis of genetic stability, growth curve, carbon utilization and scanning electronic microscopy showed that, except for 5-FU resistance, there were no significant differences between the wild type and mutant lactic acid bacteria. The integration system and the upp deletion strains could be used in the insertion or deletion of genes at any location of the chromosome of both L. casei ATCC 393 and L. lactis MG1363, and the homologous recombination would not introduce any selectable markers or residual bases. These mutant strains can be further investigated for heterologous protein expression and construction of a live mucosal vaccine carrier. Copyright © 2014 Elsevier B.V. All rights reserved.

Vaccination with nontoxic mutant toxic shock syndrome toxin 1 protects against Staphylococcus aureus infection.

PubMed

Hu, Dong-Liang; Omoe, Katsuhiko; Sasaki, Sanae; Sashinami, Hiroshi; Sakuraba, Hirotake; Yokomizo, Yuichi; Shinagawa, Kunihiro; Nakane, Akio

2003-09-01

To investigate whether vaccination with nontoxic mutant toxic shock syndrome toxin 1 (mTSST-1) can protect against Staphylococcus aureus infection, mice were vaccinated with mTSST-1 and challenged with viable S. aureus. Survival in the mTSST-1-vaccinated group was higher, and bacterial counts in organs were significantly lower than those of control mice. Passive transfer of mTSST-1-specific antibodies also provided protection against S. aureus-induced septic death. Interferon (IFN)-gamma production in the serum samples and spleens from vaccinated mice was significantly decreased compared with that in controls, whereas interleukin-10 titers were significantly higher in vaccinated mice. IFN-gamma and tumor necrosis factor-alpha production in vitro were significantly inhibited by serum samples from mTSST-1-immunized mice but not from control mice. These results suggest that vaccination with mTSST-1 devoid of superantigenic properties provides protection against S. aureus infection and that the protection might be mediated by TSST-1-neutralizing antibodies as well as by the down-regulation of IFN-gamma production.

Mechanisms of Cross-protection by Influenza Virus M2-based Vaccines.

PubMed

Lee, Yu-Na; Kim, Min-Chul; Lee, Young-Tae; Kim, Yu-Jin; Kang, Sang-Moo

2015-10-01

Current influenza virus vaccines are based on strain-specific surface glycoprotein hemagglutinin (HA) antigens and effective only when the predicted vaccine strains and circulating viruses are well-matched. The current strategy of influenza vaccination does not prevent the pandemic outbreaks and protection efficacy is reduced or ineffective if mutant strains emerge. It is of high priority to develop effective vaccines and vaccination strategies conferring a broad range of cross protection. The extracellular domain of M2 (M2e) is highly conserved among human influenza A viruses and has been utilized to develop new vaccines inducing cross protection against different subtypes of influenza A virus. However, immune mechanisms of cross protection by M2e-based vaccines still remain to be fully elucidated. Here, we review immune correlates and mechanisms conferring cross protection by M2e-based vaccines. Molecular and cellular immune components that are known to be involved in M2 immune-mediated protection include antibodies, B cells, T cells, alveolar macrophages, Fc receptors, complements, and natural killer cells. Better understanding of protective mechanisms by immune responses induced by M2e vaccination will help facilitate development of broadly cross protective vaccines against influenza A virus.

Strain diversity plays no major role in the varying efficacy of rotavirus vaccines: an overview.

PubMed

Velasquez, Daniel E; Parashar, Umesh D; Jiang, Baoming

2014-12-01

While a monovalent Rotarix® [RV1] and a pentavalent RotaTeq® [RV5] have been extensively tested and found generally safe and equally efficacious in clinical trials, the question still lingers about the evolving diversity of circulating rotavirus strains over time and their relationship with protective immunity induced by rotavirus vaccines. We reviewed data from clinical trials and observational studies that assessed the efficacy or field effectiveness of rotavirus vaccines against different rotavirus strains worldwide. RV1 provided broad clinical efficacy and field effectiveness against severe diarrhea due to all major circulating strains, including the homotypic G1P[8] and the fully heterotypic G2P[4] strains. Similarly, RV5 provided broad efficacy and effectiveness against RV5 and non-RV5 strains throughout different locations. Rotavirus vaccination provides broad heterotypic protection; however continuing surveillance is needed to track the change of circulating strains and monitor the effectiveness and safety of vaccines. Published by Elsevier B.V.

A low-toxic site-directed mutant of Clostridium perfringens ε-toxin as a potential candidate vaccine against enterotoxemia.

PubMed

Li, Qing; Xin, Wenwen; Gao, Shan; Kang, Lin; Wang, Jinglin

2013-11-01

Clostridium perfringens epsilon toxin (ETX), one of the most potent toxins known, is a potential biological weapon; therefore, the development of an effective vaccine is important for preventing intoxication or disease by ETX. In this study, genetically detoxified epsilon toxin mutants were developed as candidate vaccines. We used site-directed mutagenesis to mutate the essential amino acid residues (His106, Ser111 and Phe199). Six site-directed mutants of ETX (mETX (H106P) , mETX (S111H) , mETX (S111Y) , mETX (F199H) , mETX (F199E) , mETX (S111YF199E) ) were generated and then expressed in Escherichia coli. Both mETX (F199E) and mETX (H106P) with low or non-cytotoxicity that retained their immunogenicity were selected to immunize mice 3 times, and the mouse survival data were recorded after challenging with recombinant wild-type ETX. mETX (F199E) induces the same protection as mETX (H106P) , which was reported previously as a promising toxin mutant for vaccine, and both of them could protect immunized mice against a 100× LD₅₀ dose of active wild-type recombinant ETX. This work showed that mETX (F199E) is another promising candidate vaccine against enterotoxemia and other diseases caused by ETX.

Classical Swine Fever Outbreak after Modified Live LOM Strain Vaccination in Naive Pigs, South Korea

PubMed Central

Je, Sang H.; Kwon, Taeyong; Yoo, Sung J.; Lee, Dong-Uk; Lee, SeungYoon; Richt, Juergen A.

2018-01-01

We report classical swine fever outbreaks occurring in naive pig herds on Jeju Island, South Korea, after the introduction of the LOM vaccine strain. Two isolates from sick pigs had >99% identity with the vaccine stain. LOM strain does not appear safe; its use in the vaccine should be reconsidered. PMID:29553332

Differentiation of Mycoplasma gallisepticum vaccine strains ts-11 and 6/85 from commonly used Mycoplasma gallisepticum challenge strains by PCR.

PubMed

Evans, J D; Leigh, S A

2008-09-01

Mycoplasma gallisepticum (MG) is an important avian pathogen causing significant economic losses within the poultry industry. In an effort to develop tools to aid in MG research and diagnostics, we have compared sequences of the attenuated MG vaccine strain ts-11 to those of commonly used pathogenic challenge strains in search of a simple means of differentiation. Via gapA sequence alignments and comparisons, we have identified and designed primers facilitating strain differentiation. When applied to conventional polymerase chain reaction (PCR) assay at low annealing temperature, the primer sets allow for the differentiation of MG attenuated vaccine strains ts-11 as well as the attenuated MG vaccine strain 6/85 from the commonly utilized MG challenge strains R(low), R, and S6. Conventional PCR differentiation is based on the visualization of sole products with the attenuated MG strains ts-11 and 6/85 and the lack of the corresponding products from MG strains R(low), R, and S6. When applied to MG strain F, product visualization varies with the applied primer set. The differentiation of MG strains ts-11 and 6/85 from the pathogenic challenge strains was also accomplished via real-time analyses, however, the primer sets were not able to differentiate MG strains ts-11 and 6/85 from selected MG field isolates.

Protective activity and immunogenicity of two recombinant anthrax vaccines for veterinary use.

PubMed

Fasanella, A; Tonello, F; Garofolo, G; Muraro, L; Carattoli, A; Adone, R; Montecucco, C

2008-10-23

In this study, the efficacy of two experimental vaccines against Bacillus anthracis toxinaemia was evaluated in the rabbit model. A recombinant Protective Antigen (rPA) mutant and a trivalent vaccine (TV) composed by the rPA, a inactive mutant of Lethal Factor (mLF-Y728A; E735A) and a inactive mutant of Edema Factor (mEF-K346R), both emulsified with mineral oils, were evaluated for their immunogenicity and protective activity in New Zealand white rabbits. Rabbits vaccinated subcutaneously with rPA and TV rapidly produced high level of anti-PA, anti-LF and anti-EF antibodies, which were still present 6 months later. In the efficacy test, these vaccines protected 100% of rabbits challenged with B. anthracis virulent strain 0843 one week after the vaccination. Moreover, all animals vaccinated twice with rPA and TV, resisted B. anthracis infection 6 months later. Our data indicate that rPA and TV could be good vaccine candidates for inducing protection against B. anthracis infection in target animal host. They could successfully be used in an emergency with simultaneous long-acting antibiotics to halt incubating infections or during an anthrax epidemic.

Effectiveness of Meningococcal B Vaccine against Endemic Hypervirulent Neisseria meningitidis W Strain, England

PubMed Central

Giuliani, Marzia Monica; Biolchi, Alessia; Pizza, Mariagrazia; Beebeejaun, Kazim; Lucidarme, Jay; Findlow, Jamie; Ramsay, Mary E.; Borrow, Ray

2016-01-01

Serum samples from children immunized with a meningococcal serogroup B vaccine demonstrated potent serum bactericidal antibody activity against the hypervirulent Neisseria meningitidis serogroup W strain circulating in England. The recent introduction of this vaccine into the United Kingdom national immunization program should also help protect infants against this endemic strain. PMID:26811872

Inactivation of SAM-Methyltransferase is the Mechanism of Attenuation of a Historic Louse Borne Typhus Vaccine Strain

PubMed Central

Liu, Yan; Wu, Bin; Weinstock, George; Walker, David H.; Yu, Xue-jie

2014-01-01

Louse borne typhus (also called epidemic typhus) was one of man's major scourges, and epidemics of the disease can be reignited when social, economic, or political systems are disrupted. The fear of a bioterrorist attack using the etiologic agent of typhus, Rickettsia prowazekii, was a reality. An attenuated typhus vaccine, R. prowazekii Madrid E strain, was observed to revert to virulence as demonstrated by isolation of the virulent revertant Evir strain from animals which were inoculated with Madrid E strain. The mechanism of the mutation in R. prowazekii that affects the virulence of the vaccine was not known. We sequenced the genome of the virulent revertant Evir strain and compared its genome sequence with the genome sequences of its parental strain, Madrid E. We found that only a single nucleotide in the entire genome was different between the vaccine strain Madrid E and its virulent revertant strain Evir. The mutation is a single nucleotide insertion in the methyltransferase gene (also known as PR028) in the vaccine strain that inactivated the gene. We also confirmed that the vaccine strain E did not cause fever in guinea pigs and the virulent revertant strain Evir caused fever in guinea pigs. We concluded that a single nucleotide insertion in the methyltransferase gene of R. prowazekii attenuated the R. prowazekii vaccine strain E. This suggested that an irreversible insertion or deletion mutation in the methyl transferase gene of R. prowazekii is required for Madrid E to be considered a safe vaccine. PMID:25412248

TTSS2-deficient hha mutant of Salmonella Typhimurium exhibits significant systemic attenuation in immunocompromised hosts

PubMed Central

Vishwakarma, Vikalp; Pati, Niladri Bhusan; Ray, Shilpa; Das, Susmita; Suar, Mrutyunjay

2014-01-01

Non-typhoidal Salmonella (NTS) infections are emerging as leading problem worldwide and the variations in host immune status append to the concern of NTS. Salmonella enterica serovar Typhimurium is one of the causative agents of NTS infections and has been extensively studied. The inactivation of Salmonella pathogenicity island 2 (SPI2) encoded type-III secretion system 2 (TTSS2) has been reported rendering the strain incapable for systemic dissemination to host sites and has also been proposed as live-attenuated vaccine. However, infections from TTSS2-deficient Salmonella have also been reported. In this study, mutant strain MT15 was developed by inactivation of the hemolysin expression modulating protein (hha) in TTSS2-deficient S. Typhimurium background. The MT15 strain showed significant level of attenuation in immune-deprived murine colitis model when tested in iNos−/−, IL10−/−, and CD40L−/− mice groups in C57BL/6 background. Further, the mutation in hha does not implicate any defect in bacterial colonization to the host gut. The long-term infection of developed mutant strain conferred protective immune responses to suitably immunized streptomycin pre-treated C57BL/6 mice. The immunization enhanced the CD4+ and CD8+ cell types involved in bacterial clearance. The serum IgG and luminal secretory IgA (sIgA) was also found to be elevated after the due course of infection. Additionally, the immunized C57BL/6 mice were protected from the subsequent lethal infection of Salmonella Typhimurium. Collectively, these findings implicate the involvement of hemolysin expression modulating protein (Hha) in establishment of bacterial infection. In light of the observed attenuation of the developed mutant strain, this study proposes the possible significance of SPI2-deficient hha mutant as an alternative live-attenuated vaccine strain for use against lethal Salmonella infections. PMID:24401482

A clinical trial of WRL 105 strain live attenuated influenza vaccine comparing four methods of intranasal vaccination.

PubMed Central

Freestone, D. S.; Bowker, C. H.; Letley, E.; Ferris, R. D.; White, W. G.; Barnes, G. M.

1976-01-01

A single intranasal dose of 10(7-0) EID50 recombinant WRL 105 strain live attenuated influenza vaccine was administered intranasally to 193 volunteers either as nose drops or by one of three spray devices which produced sprays of differing physical characteristics. In volunteers with homologous haemagglutinating inhibiting antibody titres of less than or equal to 20 before vaccination, seroconversion rates varied widely from 80% following the administration of drops to 71%, 57% and 28% with the three spray devices. In the week following vaccination 16 (22%) of 74 volunteers who were found to show a fourfold or greater antibody response to took analgesics to control symptoms in comparison with 4 (7%) of 58 volunteers who exhibited no serological response to vaccination (P less than 0-05). However, neither the occurrence of upper respiratory nor systemic symptoms were significantly different in these two groups and the degree of attenuation of the recombinant WRL 105 strain appears to be acceptable for future use. PMID:1064672

Strain improvement and metabolic flux analysis in the wild-type and a mutant Lactobacillus lactis strain for L(+)-lactic acid production.

PubMed

Bai, Dong-Mei; Zhao, Xue-Ming; Li, Xin-Gang; Xu, Shi-Min

2004-12-20

The effects of initial glucose concentration and calcium lactate concentration on the lactic acid production by the parent strain, Lactobacillus lactis BME5-18, were studied. The results of the experiments indicated that glucose and lactate repressed the cell growth and the lactic acid production by Lactobacillus lactis BME5-18. A L(+)-lactic acid overproducing strain, Lactobacillus lactis BME5-18M, was screened by mutagenizing the parent strain with ultraviolet (UV) light irradiation and selecting the high glucose and lactate calcium concentration repression resistant mutant. Starting with a concentration of 100g L(-1) glucose, the mutant produced 98.6 g L(-1) lactic acid after 60 h in flasks, 73.9% higher than that of the parent strain. The L(+)-lactic acid purity was 98.1% by weight based on the amount of total lactic acid. The culture of the parent strain could not be analyzed well by conventional metabolic flux analysis techniques, since some pyruvate were accumulated intracellularly. Therefore, a revised flux analysis method was proposed by introducing intracellular pyruvate pool. Further studies demonstrate that there is a high level of NADH oxidase activity (12.11 mmol mg(-1) min(-1)) in the parent strain. The molecular mechanisms of the strain improvement were proposed, i.e., the high level of NADH oxidase activity was eliminated and the uptake rate of glucose was increased from 82.1 C-mmol (g DW h)(-1) to 98.9 C-mmol (g DW h)(-1) by mutagenizing the parent strain with UV, and therefore the mutant strain converts mostly pyruvate to lactic acid with a higher productivity (1.76 g L(-1) h(-1)) than the parent strain (0.95 g L(-1) h(-1)).

Rational design of a live attenuated dengue vaccine: 2'-o-methyltransferase mutants are highly attenuated and immunogenic in mice and macaques.

PubMed

Züst, Roland; Dong, Hongping; Li, Xiao-Feng; Chang, David C; Zhang, Bo; Balakrishnan, Thavamalar; Toh, Ying-Xiu; Jiang, Tao; Li, Shi-Hua; Deng, Yong-Qiang; Ellis, Brett R; Ellis, Esther M; Poidinger, Michael; Zolezzi, Francesca; Qin, Cheng-Feng; Shi, Pei-Yong; Fink, Katja

2013-01-01

Dengue virus is transmitted by Aedes mosquitoes and infects at least 100 million people every year. Progressive urbanization in Asia and South-Central America and the geographic expansion of Aedes mosquito habitats have accelerated the global spread of dengue, resulting in a continuously increasing number of cases. A cost-effective, safe vaccine conferring protection with ideally a single injection could stop dengue transmission. Current vaccine candidates require several booster injections or do not provide protection against all four serotypes. Here we demonstrate that dengue virus mutants lacking 2'-O-methyltransferase activity are highly sensitive to type I IFN inhibition. The mutant viruses are attenuated in mice and rhesus monkeys and elicit a strong adaptive immune response. Monkeys immunized with a single dose of 2'-O-methyltransferase mutant virus showed 100% sero-conversion even when a dose as low as 1,000 plaque forming units was administrated. Animals were fully protected against a homologous challenge. Furthermore, mosquitoes feeding on blood containing the mutant virus were not infected, whereas those feeding on blood containing wild-type virus were infected and thus able to transmit it. These results show the potential of 2'-O-methyltransferase mutant virus as a safe, rationally designed dengue vaccine that restrains itself due to the increased susceptibility to the host's innate immune response.

Altered Regulation of Escherichia coli Biotin Biosynthesis in BirA Superrepressor Mutant Strains

PubMed Central

Chakravartty, Vandana

2012-01-01

Transcription of the Escherichia coli biotin (bio) operon is directly regulated by the biotin protein ligase BirA, the enzyme that covalently attaches biotin to its cognate acceptor proteins. Binding of BirA to the bio operator requires dimerization of the protein, which is triggered by BirA-catalyzed synthesis of biotinoyl-adenylate (biotinoyl-5′-AMP), the obligatory intermediate of the ligation reaction. Although several aspects of this regulatory system are well understood, no BirA superrepressor mutant strains had been isolated. Such superrepressor BirA proteins would repress the biotin operon transcription in vivo at biotin concentrations well below those needed for repression by wild-type BirA. We isolated mutant strains having this phenotype by a combined selection-screening approach and resolved multiple mutations to give several birA superrepressor alleles, each having a single mutation, all of which showed repression dominant over that of the wild-type allele. All of these mutant strains repressed bio operon transcription in vivo at biotin concentrations that gave derepression of the wild-type strain and retained sufficient ligation activity for growth when overexpressed. All of the strains except that encoding G154D BirA showed derepression of bio operon transcription upon overproduction of a biotin-accepting protein. In BirA, G154D was a lethal mutation in single copy, and the purified protein was unable to transfer biotin from enzyme-bound biotinoyl-adenylate either to the natural acceptor protein or to a biotin-accepting peptide sequence. Consistent with the transcriptional repression data, each of the purified mutant proteins showed increased affinity for the biotin operator DNA in electrophoretic mobility shift assays. Surprisingly, although most of the mutations were located in the catalytic domain, all of those tested, except G154D BirA, had normal ligase activity. Most of the mutations that gave superrepressor phenotypes altered residues

Comparative Proteome Analysis of Brucella melitensis Vaccine Strain Rev 1 and a Virulent Strain, 16M

PubMed Central

Eschenbrenner, Michel; Wagner, Mary Ann; Horn, Troy A.; Kraycer, Jo Ann; Mujer, Cesar V.; Hagius, Sue; Elzer, Philip; DelVecchio, Vito G.

2002-01-01

The genus Brucella consists of bacterial pathogens that cause brucellosis, a major zoonotic disease characterized by undulant fever and neurological disorders in humans. Among the different Brucella species, Brucella melitensis is considered the most virulent. Despite successful use in animals, the vaccine strains remain infectious for humans. To understand the mechanism of virulence in B. melitensis, the proteome of vaccine strain Rev 1 was analyzed by two-dimensional gel electrophoresis and compared to that of virulent strain 16M. The two strains were grown under identical laboratory conditions. Computer-assisted analysis of the two B. melitensis proteomes revealed proteins expressed in either 16M or Rev 1, as well as up- or down-regulation of proteins specific for each of these strains. These proteins were identified by peptide mass fingerprinting. It was found that certain metabolic pathways may be deregulated in Rev 1. Expression of an immunogenic 31-kDa outer membrane protein, proteins utilized for iron acquisition, and those that play a role in sugar binding, lipid degradation, and amino acid binding was altered in Rev 1. PMID:12193611

Comparative proteome analysis of Brucella melitensis vaccine strain Rev 1 and a virulent strain, 16M.

PubMed

Eschenbrenner, Michel; Wagner, Mary Ann; Horn, Troy A; Kraycer, Jo Ann; Mujer, Cesar V; Hagius, Sue; Elzer, Philip; DelVecchio, Vito G

2002-09-01

The genus Brucella consists of bacterial pathogens that cause brucellosis, a major zoonotic disease characterized by undulant fever and neurological disorders in humans. Among the different Brucella species, Brucella melitensis is considered the most virulent. Despite successful use in animals, the vaccine strains remain infectious for humans. To understand the mechanism of virulence in B. melitensis, the proteome of vaccine strain Rev 1 was analyzed by two-dimensional gel electrophoresis and compared to that of virulent strain 16M. The two strains were grown under identical laboratory conditions. Computer-assisted analysis of the two B. melitensis proteomes revealed proteins expressed in either 16M or Rev 1, as well as up- or down-regulation of proteins specific for each of these strains. These proteins were identified by peptide mass fingerprinting. It was found that certain metabolic pathways may be deregulated in Rev 1. Expression of an immunogenic 31-kDa outer membrane protein, proteins utilized for iron acquisition, and those that play a role in sugar binding, lipid degradation, and amino acid binding was altered in Rev 1.

Comparative production of 6-aminopenicillanic acid by different E. coli strains and their acridine orange (AO) induced mutants.

PubMed

Arshad, Rubina; Farooq, Shafqat; Ali, Syed Shahid

2007-11-01

The present study was conducted to see the difference in production of 6-APA I) between wild strains of E. coli collected from local environment and their acridine orange (AO) induced mutants and ii) between mutants and E. coli strains (ATCC 11105 and ATCC 9637) of American Type Culture Collection (ATCC) used commercially for enzymatic production of 6-APA. The optimum conditions for bioconversion were standardized and 6-APA was obtained in crystalline form. Relative PGA activity of local and foreign E. coli strains varied significantly with the highest being 12.7 in mutant strain (BDCS-N-M36) and the lowest 4.3 mg 6-APA h(-1) mg(-1) wet cells in foreign strain (ATCC 11105). The enzyme activity exhibited by mutant strain (BDCS-N-M36) was also two folds higher compared to that in wild parent BDCS-N-W50 (6.3 mg 6-APA h(-1) mg(-1) wet cells). The overall production of 6-APA and conversion ratios ranged between 0.25-0.41 g of 6-APA per 0.5 g of penicillin G and 51-83%, respectively. Maximum conversion ratio (83%) was achieved by using crude cells of mutant strain (BDCS-N-M36) which is the highest value ever reported by crude cells on a shake-flask scale whereas reported 6-APA production by immobilized cells is 60-90% in batch and continuous systems. Results are being discussed with reference to importance of local bacterial strains and their significance for industrially important enzymes.

[Virus strain specific serum neutralizing antibodies in children and adolescents immunized with a Russian mumps vaccine].

PubMed

Otrashevskaia, E V; Krasil'nikov, I V; Ignat'ev, G M

2010-01-01

Postvaccination immunity was studied in the children and teenagers without a history of clinical mumps infection, who had been immunized with the Leningrad-3 mumps vaccine. The level of specific lgG in ELISA and that and spectrum of their neutralizing activity against a vaccine strain and three heterologous mumps virus (MV) strains (genotypes A, C, and H) were measured. The investigation included 151 sera from the vaccinees aged 3 to 17 years, possessing the detectable specific IgG titers in ELISA and the detectable neutralizing titers against the vaccine strain. 97.4% of the vaccinees had neutralizing activity against 1-3 heterologous MV strains. A preponderance of neutralizing titers against heterologous MV strains by 1-log2 in some sera (6.5-32.5 depending on age) was most likely to suggest that the vaccinees' had been in contact with these virus strains in the past. In our investigation, a combination of positive IgG titers and neutralizing titers against the vaccine strain 2-log2 or higher provided the protection of the vaccinated children and teenagers against the symptomatic infection. There was a pronounced buster effect of the second immunization and a drop in the neutralizing activity of the sera from the vaccinated children and adolescents over time after the first and second immunization.

Field study of vaccination of cattle with Brucella abortus strains RB51 and 19 under high and low disease prevalence.

PubMed

Lord, V R; Schurig, G G; Cherwonogrodzky, J W; Marcano, M J; Melendez, G E

1998-08-01

To assess humoral and protective immunity in cattle vaccinated by 12 months with Brucella abortus vaccine strains RB51 and 19 under field conditions of high and low brucellosis prevalence. 450 seronegative female cattle: 330 three to eight months old (calves), and 120 ten to twelve months old (heifers). Ranch A had high prevalence (39%) of brucellosis, and ranch B had low prevalence (2%), as determined by results of conventional serologic testing: agar gel immunodiffusion and the ring test. Seronegative cattle were vaccinated once or twice with 5 x 10(9) colony-forming units of B abortus strain RB51 or once with strain 19. After vaccinating 285 cattle with strain RB51 and 165 with strain 19, 74 (26%) and 30 (18%), respectively, were bred to seropositive bulls, then were kept within the infected herd of origin. All cattle vaccinated with strain 19 seroconverted 30 days later. All 285 cattle vaccinated with strain RB51 had negative results for all serologic tests, including agar gel immunodiffusion. All RB51-vaccinated cattle that became pregnant had negative results for the ring test and for conventional serologic tests after their first calving. Strain RB51 can be used as a live organism vaccine without inducing antibody titers that interfere with serodiagnosis, and induced 100% protection against field strain B abortus-induced abortion in cattle vaccinated at least 1 year before mating to an infected bull. Vaccination with strain 19 under similar conditions was less effective than vaccination with strain RB51.

Effect of fusion protein cleavage site sequence on generation of a genotype VII Newcastle disease virus vaccine.

PubMed

Manoharan, Vinoth K; Varghese, Berin P; Paldurai, Anandan; Samal, Siba K

2018-01-01

Newcastle disease (ND) causes severe economic loss to poultry industry worldwide. Frequent outbreaks of ND in commercial chickens vaccinated with live vaccines suggest a need to develop improved vaccines that are genetically matched against circulating Newcastle disease virus (NDV) strains. In this study, the fusion protein cleavage site (FPCS) sequence of NDV strain Banjarmasin/010 (Banj), a genotype VII NDV, was individually modified using primer mutagenesis to those of avian paramyxovirus (APMV) serotypes 2, 7 and 8 and compared with the recombinant Banjarmasin (rBanj) with avirulent NDV LaSota cleavage site (rBanj-LaSota). These FPCS mutations changed the in vitro cell-to-cell fusion activity and made rBanj FPCS mutant viruses highly attenuated in chickens. When chickens immunized with the rBanj FPCS mutant viruses and challenged with the virulent Banj, there was reduced challenge virus shedding observed compared to chickens immunized with the heterologous vaccine strain LaSota. Among the genotype VII NDV Banj vaccine candidates, rBanj-LaSota and rBanj containing FPCS of APMV-8 induced highest neutralizing antibody titers and protected chickens with reduced challenge virus shedding. These results show the effect of the F protein cleavage site sequence in generating genotype VII matched NDV vaccines.

Protective role of adenylate cyclase in the context of a live pertussis vaccine candidate.

PubMed

Lim, Annabelle; Ng, Jowin K W; Locht, Camille; Alonso, Sylvie

2014-01-01

Despite high vaccination coverage, pertussis remains an important respiratory infectious disease and the least-controlled vaccine-preventable infectious disease in children. Natural infection with Bordetella pertussis is known to induce strong and long-lasting immunity that wanes later than vaccine-mediated immunity. Therefore, a live attenuated B. pertussis vaccine, named BPZE1, has been developed and has recently completed a phase I clinical trial in adult human volunteers. In this study, we investigated the contribution of adenylate cyclase (CyaA) in BPZE1-mediated protection against pertussis. A CyaA-deficient BPZE1 mutant was thus constructed. Absence of CyaA did not compromise the adherence properties of the bacteria onto mammalian cells. However, the CyaA-deficient mutant displayed a slight impairment in the ability to survive within macrophages compared to the parental BPZE1 strain. In vivo, whereas the protective efficacy of the CyaA-deficient mutant was comparable to the parental strain at a vaccine dose of 5 × 10(5) colony forming units (CFU), it was significantly impaired at a vaccine dose of 5 × 10(3) CFU. This impairment correlated with impaired lung colonization ability, and impaired IFN-γ production in the animal immunized with the CyaA-deficient BPZE1 mutant while the pertussis-specific antibody profile and Th17 response were comparable to those observed in BPZE1-immunized mice. Our findings thus support a role of CyaA in BPZE1-mediated protection through induction of cellular mediated immunity. Copyright © 2013 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Vaccination with a modified-live bovine viral diarrhea virus (BVDV) type 1a vaccine completely protected calves against challenge with BVDV type 1b strains.

PubMed

Xue, Wenzhi; Mattick, Debra; Smith, Linda; Umbaugh, Jerry; Trigo, Emilio

2010-12-10

Vaccination plays a significant role in the control of bovine viral diarrhea virus (BVDV) infection and spread. Recent studies revealed that type 1b is the predominant BVDV type 1 subgenotype, representing more than 75% of field isolates of BVDV-1. However, nearly all current, commercially available BVDV type 1 vaccines contain BVDV-1a strains. Previous studies have indicated that anti-BVDV sera, induced by BVDV-1a viruses, show less neutralization activity to BVDV-1b isolates than type 1a. Therefore, it is critically important to evaluate BVDV-1a vaccines in their ability to prevent BVDV-1b infection in calves. In current studies, calves were vaccinated subcutaneously, intradermally or intranasally with a single dose of a multivalent, modified-live viral vaccine containing a BVDV-1a strain, and were challenged with differing BVDV-1b strains to determine the efficacy and duration of immunity of the vaccine against these heterologous virus strains. Vaccinated calves, in all administration routes, were protected from respiratory disease caused by the BVDV-1b viruses, as indicated by significantly fewer clinical signs, lower rectal temperatures, reduced viral shedding and greater white blood cell counts than non-vaccinated control animals. The BVDV-1a vaccine elicited efficacious protection in calves against each BVDV-1b challenge strain, with a duration of immunity of at least 6 months. Copyright © 2010 Elsevier Ltd. All rights reserved.

An inactivated gE-deleted pseudorabies vaccine provides complete clinical protection and reduces virus shedding against challenge by a Chinese pseudorabies variant.

PubMed

Wang, Jichun; Guo, Rongli; Qiao, Yongfeng; Xu, Mengwei; Wang, Zhisheng; Liu, Yamei; Gu, Yiqi; Liu, Chang; Hou, Jibo

2016-12-07

Since the end of 2011 an outbreak of pseudorabies affected Chinese pig herds that had been vaccinated with the commercial vaccine made of Bartha K61 strain. It is now clear that the outbreak was caused by an emergent PRV variant. Even though vaccines made of PRV Bartha K61 strain can confer certain cross protection against PRV variants based on experimental data, less than optimal clinical protection and virus shedding reduction were observed, making the control or eradication of this disease difficult. An infectious clone of PRV AH02LA strain was constructed to generate a gE deletion mutant PRV(LA-A B ) strain. PRV(LA-A B ) strain can reach a titer of 10 8.43 TCID 50 /mL (50% tissue culture infectious dose) on BHK-21 cells. To evaluate the efficiency of the inactivated vaccine made of PRV(LA-A B ) strain, thirty 3-week-old PRV-negative piglets were divided randomly into six groups for vaccination and challenge test. All five piglets in the challenge control showed typical clinical symptoms of pseudorabies post challenge. Sneezing and nasal discharge were observed in four and three piglets in groups C(vaccinated with inactivated PRV Bartha K61 strain vaccine) and D(vaccinated with live PRV Bartha K61 strain vaccine) respectively. In contrast, piglets in both groups A(vaccinated with inactivated PRV LA-AB strain vaccine) and B(vaccinated with inactivated PRV LA-A B strain vaccine with adjuvant) presented mild or no clinical symptoms. Moreover, viral titers detected via nasal swabs were approximately 100 times lower in group B than in the challenge control, and the duration of virus shedding (3-4 days) was shorter than in either the challenge control (5-10 days) or groups C and D (5-6 days). The infectious clone constructed in this study harbors the whole genome of the PRV variant AH02LA strain. The gE deletion mutant PRV(LA-A B )strain generated from PRV AH02LA strain can reach a high titer on BHK-21 cells. An inactivated vaccine of PRV LA-A B provides clinical

Cold-Adapted Viral Attenuation (CAVA): Highly Temperature Sensitive Polioviruses as Novel Vaccine Strains for a Next Generation Inactivated Poliovirus Vaccine

PubMed Central

Sanders, Barbara P.; de los Rios Oakes, Isabel; van Hoek, Vladimir; Bockstal, Viki; Kamphuis, Tobias; Uil, Taco G.; Song, Yutong; Cooper, Gillian; Crawt, Laura E.; Martín, Javier; Zahn, Roland; Lewis, John; Wimmer, Eckard; Custers, Jerome H. H. V.; Schuitemaker, Hanneke; Cello, Jeronimo; Edo-Matas, Diana

2016-01-01

The poliovirus vaccine field is moving towards novel vaccination strategies. Withdrawal of the Oral Poliovirus Vaccine and implementation of the conventional Inactivated Poliovirus Vaccine (cIPV) is imminent. Moreover, replacement of the virulent poliovirus strains currently used for cIPV with attenuated strains is preferred. We generated Cold-Adapted Viral Attenuation (CAVA) poliovirus strains by serial passage at low temperature and subsequent genetic engineering, which contain the capsid sequences of cIPV strains combined with a set of mutations identified during cold-adaptation. These viruses displayed a highly temperature sensitive phenotype with no signs of productive infection at 37°C as visualized by electron microscopy. Furthermore, decreases in infectious titers, viral RNA, and protein levels were measured during infection at 37°C, suggesting a block in the viral replication cycle at RNA replication, protein translation, or earlier. However, at 30°C, they could be propagated to high titers (9.4–9.9 Log10TCID50/ml) on the PER.C6 cell culture platform. We identified 14 mutations in the IRES and non-structural regions, which in combination induced the temperature sensitive phenotype, also when transferred to the genomes of other wild-type and attenuated polioviruses. The temperature sensitivity translated to complete absence of neurovirulence in CD155 transgenic mice. Attenuation was also confirmed after extended in vitro passage at small scale using conditions (MOI, cell density, temperature) anticipated for vaccine production. The inability of CAVA strains to replicate at 37°C makes reversion to a neurovirulent phenotype in vivo highly unlikely, therefore, these strains can be considered safe for the manufacture of IPV. The CAVA strains were immunogenic in the Wistar rat potency model for cIPV, inducing high neutralizing antibody titers in a dose-dependent manner in response to D-antigen doses used for cIPV. In combination with the highly productive

Cold-Adapted Viral Attenuation (CAVA): Highly Temperature Sensitive Polioviruses as Novel Vaccine Strains for a Next Generation Inactivated Poliovirus Vaccine.

PubMed

Sanders, Barbara P; de Los Rios Oakes, Isabel; van Hoek, Vladimir; Bockstal, Viki; Kamphuis, Tobias; Uil, Taco G; Song, Yutong; Cooper, Gillian; Crawt, Laura E; Martín, Javier; Zahn, Roland; Lewis, John; Wimmer, Eckard; Custers, Jerome H H V; Schuitemaker, Hanneke; Cello, Jeronimo; Edo-Matas, Diana

2016-03-01

The poliovirus vaccine field is moving towards novel vaccination strategies. Withdrawal of the Oral Poliovirus Vaccine and implementation of the conventional Inactivated Poliovirus Vaccine (cIPV) is imminent. Moreover, replacement of the virulent poliovirus strains currently used for cIPV with attenuated strains is preferred. We generated Cold-Adapted Viral Attenuation (CAVA) poliovirus strains by serial passage at low temperature and subsequent genetic engineering, which contain the capsid sequences of cIPV strains combined with a set of mutations identified during cold-adaptation. These viruses displayed a highly temperature sensitive phenotype with no signs of productive infection at 37°C as visualized by electron microscopy. Furthermore, decreases in infectious titers, viral RNA, and protein levels were measured during infection at 37°C, suggesting a block in the viral replication cycle at RNA replication, protein translation, or earlier. However, at 30°C, they could be propagated to high titers (9.4-9.9 Log10TCID50/ml) on the PER.C6 cell culture platform. We identified 14 mutations in the IRES and non-structural regions, which in combination induced the temperature sensitive phenotype, also when transferred to the genomes of other wild-type and attenuated polioviruses. The temperature sensitivity translated to complete absence of neurovirulence in CD155 transgenic mice. Attenuation was also confirmed after extended in vitro passage at small scale using conditions (MOI, cell density, temperature) anticipated for vaccine production. The inability of CAVA strains to replicate at 37°C makes reversion to a neurovirulent phenotype in vivo highly unlikely, therefore, these strains can be considered safe for the manufacture of IPV. The CAVA strains were immunogenic in the Wistar rat potency model for cIPV, inducing high neutralizing antibody titers in a dose-dependent manner in response to D-antigen doses used for cIPV. In combination with the highly productive

[Isolation and identification of Lyssavirus strains from an area of Slovakia where oral antirabies vaccine was administered].

PubMed

Ondrejka, R; Durove, A; Svrcek, S; Benísek, Z; Süliová, J

1997-02-01

The study was aimed at isolation and subsequent identification of strains of rabies virus by means of monoclonal antibodies from foxes killed in the vaccination zone within the complex preliminary monitoring of oral antirabies vaccination. The results obtained indicate that the vaccines for oral antirabies vaccination used in Slovakia did not contain any vaccination strain pathogenic to the extremely sensitive target species-the fox (Vulpes vulpes).

Yersinia pestis with regulated delayed attenuation as a vaccine candidate to induce protective immunity against plague.

PubMed

Sun, Wei; Roland, Kenneth L; Kuang, Xiaoying; Branger, Christine G; Curtiss, Roy

2010-03-01

Two mutant strains of Yersinia pestis KIM5+, a Deltacrp mutant and a mutant with arabinose-dependent regulated delayed-shutoff crp expression (araC P(BAD) crp), were constructed, characterized in vitro, and evaluated for virulence, immunogenicity, and protective efficacy in mice. Both strains were highly attenuated by the subcutaneous (s.c.) route. The 50% lethal doses (LD(50)s) of the Deltacrp and araC P(BAD) crp mutants were approximately 1,000,000-fold and 10,000-fold higher than those of Y. pestis KIM5+, respectively, indicating that both strains were highly attenuated. Mice vaccinated s.c. with 3.8 x 10(7) CFU of the Deltacrp mutant developed high anti-Y. pestis and anti-LcrV serum IgG titers, both with a strong Th2 bias, and induced protective immunity against subcutaneous challenge with virulent Y. pestis (80% survival) but no protection against pulmonary challenge. Mice vaccinated with 3.0 x 10(4) CFU of the araC P(BAD) crp mutant also developed high anti-Y. pestis and anti-LcrV serum IgG titers but with a more balanced Th1/Th2 response. This strain induced complete protection against s.c. challenge and partial protection (70% survival) against pulmonary challenge. Our results demonstrate that arabinose-dependent regulated crp expression is an effective strategy to attenuate Y. pestis while retaining strong immunogenicity, leading to protection against the pneumonic and bubonic forms of plague.

Biotransformation of L-tyrosine to Dopamine by a Calcium Alginate Immobilized Mutant Strain of Aspergillus oryzae.

PubMed

Ali, Sikander; Nawaz, Wajeeha

2016-08-01

The present research work is concerned with the biotransformation of L-tyrosine to dopamine (DA) by calcium alginate entrapped conidiospores of a mutant strain of Aspergillus oryzae. Different strains of A. oryzae were isolated from soil. Out of 13 isolated strains, isolate-2 (I-2) was found to be a better DA producer. The wild-type I-2 was chemically improved by treating it with different concentrations of ethyl methyl sulfonate (EMS). Among seven mutant variants, EMS-6 exhibiting maximal DA activity of 43 μg/ml was selected. The strain was further exposed with L-cysteine HCl to make it resistant against diversion and environmental stress. The conidiospores of selected mutant variant A. oryzae EMS-6 strain were entrapped in calcium alginate beads. Different parameters for immobilization were investigated. The activity was further improved from 44 to 62 μg/ml under optimized conditions (1.5 % sodium alginate, 2 ml inoculum, and 2 mm bead size). The best resistant mutant variable exhibited over threefold increase in DA activity (62 μg/ml) than did wild-type I-2 (21 μg/ml) in the reaction mixture. From the results presented in the study, it was observed that high titers of DA activity in vitro could effectively be achieved by the EMS-induced mutagenesis of filamentous fungus culture used.

Generation of a Listeria vaccine strain by enhanced Caspase-1 activation

PubMed Central

Warren, Sarah E.; Duong, Hien; Mao, Dat Phat; Armstrong, Abraham; Rajan, Jayant; Miao, Edward A.; Aderem, Alan

2012-01-01

The immunostimulatory properties conferred by vaccine adjuvants require Caspase-1 for processing of IL-1β and IL-18. Caspase-1 is activated in response to a breach of the cytosolic compartment by microbes and the process is initiated by intracellular pattern recognition receptors within inflammasomes. Listeria monocytogenes is detected in the cytosol by the NLRC4, NLRP3 and AIM2 inflammasomes. NLRC4 is activated by flagellin, and L. monocytogenes evades this detector by repressing flagellin expression. We generated an L. monocytogenes strain that was forced to express flagellin in the host cell cytosol. This strain hyperactivated Caspase-1 and was preferentially cleared via NLRC4 detection in an IL-1β/IL-18 independent manner. We also created a strain of L. monocytogenes with forced expression of another NLRC4 agonist, PrgJ from the Type III secretion system of S. typhimurium. Forced expression of flagellin or PrgJ resulted in attenuation, yet both strains conferred protective immunity in mice against lethal challenge with L. monocytogenes. This work is the first demonstration of specific targeting of the Caspase-1 activation pathway to generate a safe and potent L. monocytogenes based vaccine. Moreover, the attenuated strains with embedded flagellin or PrgJ adjuvants, represent attractive vectors for vaccines aimed at eliciting T cell responses. PMID:21538346

Foot-and-Mouth Disease (FMD) Virus 3C Protease Mutant L127P: Implications for FMD Vaccine Development.

PubMed

Puckette, Michael; Clark, Benjamin A; Smith, Justin D; Turecek, Traci; Martel, Erica; Gabbert, Lindsay; Pisano, Melia; Hurtle, William; Pacheco, Juan M; Barrera, José; Neilan, John G; Rasmussen, Max

2017-11-15

The foot-and-mouth disease virus (FMDV) afflicts livestock in more than 80 countries, limiting food production and global trade. Production of foot-and-mouth disease (FMD) vaccines requires cytosolic expression of the FMDV 3C protease to cleave the P1 polyprotein into mature capsid proteins, but the FMDV 3C protease is toxic to host cells. To identify less-toxic isoforms of the FMDV 3C protease, we screened 3C mutants for increased transgene output in comparison to wild-type 3C using a Gaussia luciferase reporter system. The novel point mutation 3C(L127P) increased yields of recombinant FMDV subunit proteins in mammalian and bacterial cells expressing P1-3C transgenes and retained the ability to process P1 polyproteins from multiple FMDV serotypes. The 3C(L127P) mutant produced crystalline arrays of FMDV-like particles in mammalian and bacterial cells, potentially providing a practical method of rapid, inexpensive FMD vaccine production in bacteria. IMPORTANCE The mutant FMDV 3C protease L127P significantly increased yields of recombinant FMDV subunit antigens and produced virus-like particles in mammalian and bacterial cells. The L127P mutation represents a novel advancement for economical FMD vaccine production. Copyright © 2017 Puckette et al.

Enhanced mucosal delivery of antigen with cell wall mutants of lactic acid bacteria.

PubMed

Grangette, Corinne; Müller-Alouf, Heide; Hols, Pascal; Goudercourt, Denise; Delcour, Jean; Turneer, Mireille; Mercenier, Annick

2004-05-01

The potential of recombinant lactic acid bacteria (LAB) to deliver heterologous antigens to the immune system and to induce protective immunity has been best demonstrated by using the C subunit of tetanus toxin (TTFC) as a model antigen. Two types of LAB carriers have mainly been used, Lactobacillus plantarum and Lactococcus lactis, which differ substantially in their abilities to resist passage through the stomach and to persist in the mouse gastrointestinal tract. Here we analyzed the effect of a deficiency in alanine racemase, an enzyme that participates in cell wall synthesis, in each of these bacterial carriers. Recombinant wild-type and mutant strains of L. plantarum NCIMB8826 and L. lactis MG1363 producing TTFC intracellularly were constructed and used in mouse immunization experiments. Remarkably, we observed that the two cell wall mutant strains were far more immunogenic than their wild-type counterparts when the intragastric route was used. However, intestinal TTFC-specific immunoglobulin A was induced only after immunization with the recombinant L. plantarum mutant strain. Moreover, the alanine racemase mutant of either LAB strain allowed induction of a much stronger serum TTFC-specific immune response after immunization via the vagina, which is a quite different ecosystem than the gastrointestinal tract. The design and use of these mutants thus resulted in a major improvement in the mucosal delivery of antigens exhibiting vaccine properties.

Development and introduction of inactivated poliovirus vaccines derived from Sabin strains in Japan.

PubMed

Shimizu, Hiroyuki

2016-04-07

During the endgame of global polio eradication, the universal introduction of inactivated poliovirus vaccines is urgently required to reduce the risk of vaccine-associated paralytic poliomyelitis and polio outbreaks due to wild and vaccine-derived polioviruses. In particular, the development of inactivated poliovirus vaccines (IPVs) derived from the attenuated Sabin strains is considered to be a highly favorable option for the production of novel IPV that reduce the risk of facility-acquired transmission of poliovirus to the communities. In Japan, Sabin-derived IPVs (sIPVs) have been developed and introduced for routine immunization in November 2012. They are the first licensed sIPVs in the world. Consequently, trivalent oral poliovirus vaccine was used for polio control in Japan for more than half a century but has now been removed from the list of vaccines licensed for routine immunization. This paper reviews the development, introduction, characterization, and global status of IPV derived from attenuated Sabin strains. Copyright © 2014 Elsevier Ltd. All rights reserved.

Autodisplay: Development of an Efficacious System for Surface Display of Antigenic Determinants in Salmonella Vaccine Strains

PubMed Central

Kramer, Uwe; Rizos, Konstantin; Apfel, Heiko; Autenrieth, Ingo B.; Lattemann, Claus T.

2003-01-01

To optimize antigen delivery by Salmonella vaccine strains, a system for surface display of antigenic determinants was established by using the autotransporter secretion pathway of gram-negative bacteria. A modular system for surface display allowed effective targeting of heterologous antigens or fragments thereof to the bacterial surface by the autotransporter domain of AIDA-I, the Escherichia coli adhesin involved in diffuse adherence. A major histocompatibility complex class II-restricted epitope, comprising amino acids 74 to 86 of the Yersinia enterocolitica heat shock protein Hsp60 (Hsp6074-86), was fused to the AIDA-I autotransporter domain, and the resulting fusion protein was expressed at high levels on the cell surface of E. coli and Salmonella enterica serovar Typhimurium. Colonization studies in mice vaccinated with Salmonella strains expressing AIDA-I fusion proteins demonstrated high genetic stability of the generated vaccine strain in vivo. Furthermore, a pronounced T-cell response against Yersinia Hsp6074-86 was induced in mice vaccinated with a Salmonella vaccine strain expressing the Hsp6074-86-AIDA-I fusion protein. This was shown by monitoring Yersinia Hsp60-stimulated IFN-γ secretion and proliferation of splenic T cells isolated from vaccinated mice. These results demonstrate that the surface display of antigenic determinants by the autotransporter pathway deserves special attention regarding the application in live attenuated Salmonella vaccine strains. PMID:12654812

Autodisplay: development of an efficacious system for surface display of antigenic determinants in Salmonella vaccine strains.

PubMed

Kramer, Uwe; Rizos, Konstantin; Apfel, Heiko; Autenrieth, Ingo B; Lattemann, Claus T

2003-04-01

To optimize antigen delivery by Salmonella vaccine strains, a system for surface display of antigenic determinants was established by using the autotransporter secretion pathway of gram-negative bacteria. A modular system for surface display allowed effective targeting of heterologous antigens or fragments thereof to the bacterial surface by the autotransporter domain of AIDA-I, the Escherichia coli adhesin involved in diffuse adherence. A major histocompatibility complex class II-restricted epitope, comprising amino acids 74 to 86 of the Yersinia enterocolitica heat shock protein Hsp60 (Hsp60(74-86)), was fused to the AIDA-I autotransporter domain, and the resulting fusion protein was expressed at high levels on the cell surface of E. coli and Salmonella enterica serovar Typhimurium. Colonization studies in mice vaccinated with Salmonella strains expressing AIDA-I fusion proteins demonstrated high genetic stability of the generated vaccine strain in vivo. Furthermore, a pronounced T-cell response against Yersinia Hsp60(74-86) was induced in mice vaccinated with a Salmonella vaccine strain expressing the Hsp60(74-86)-AIDA-I fusion protein. This was shown by monitoring Yersinia Hsp60-stimulated IFN-gamma secretion and proliferation of splenic T cells isolated from vaccinated mice. These results demonstrate that the surface display of antigenic determinants by the autotransporter pathway deserves special attention regarding the application in live attenuated Salmonella vaccine strains.

Oral vaccination against bubonic plague using a live avirulent Yersinia pseudotuberculosis strain.

PubMed

Blisnick, Thierry; Ave, Patrick; Huerre, Michel; Carniel, Elisabeth; Demeure, Christian E

2008-08-01

We evaluated the possibility of using Yersinia pseudotuberculosis as a live vaccine against plague because it shares high genetic identity with Y. pestis while being much less virulent, genetically much more stable, and deliverable orally. A total of 41 Y. pseudotuberculosis strains were screened by PCR for the absence of the high pathogenicity island, the superantigens YPM, and the type IV pilus and the presence of the pYV virulence plasmid. One strain (IP32680) fulfilled these criteria. This strain was avirulent in mice upon intragastric or subcutaneous inoculation and persisted for 2 months in the mouse intestine without clinical signs of disease. IP32680 reached the mesenteric lymph nodes, spleen, and liver without causing major histological lesions and was cleared after 13 days. The antibodies produced in vaccinated animals recognized both Y. pseudotuberculosis and Y. pestis antigens efficiently. After a subcutaneous challenge with Y. pestis CO92, bacteria were found in low amounts in the organs and rarely in the blood of vaccinated animals. One oral IP32680 inoculation protected 75% of the mice, and two inoculations induced much higher antibody titers and protected 88% of the mice. Our results thus validate the concept that an attenuated Y. pseudotuberculosis strain can be an efficient, inexpensive, safe, and easy-to-produce live vaccine for oral immunization against bubonic plague.

Mechanical properties of elytra from Tribolium castaneum wild-type and body color mutant strains.

PubMed

Lomakin, Joseph; Arakane, Yasuyuki; Kramer, Karl J; Beeman, Richard W; Kanost, Michael R; Gehrke, Stevin H

2010-12-01

Cuticle tanning in insects involves simultaneous cuticular pigmentation and hardening or sclerotization. The dynamic mechanical properties of the highly modified and cuticle-rich forewings (elytra) from Tribolium castaneum (red flour beetle) wild-type and body color mutant strains were investigated to relate body coloration and elytral mechanical properties. There was no statistically significant variation in the storage modulus E' among the elytra from jet, cola, sooty and black mutants or between the mutants and the wild-type GA-1 strain: E' averaged 5.1 ± 0.6 GPa regardless of body color. E' is a power law function of oscillation frequency for all types. The power law exponent, n, averaged 0.032 ± 0.001 for elytra from all genotypes except black; this small value indicated that the elytra are cross-linked. Black elytra, however, displayed a significantly larger n of 0.047 ± 0.004 and an increased loss tangent (tan δ), suggesting that metabolic differences in the black mutant strain result in elytra that are less cross-linked and more pigmented than the other types. These results are consistent with the hypothesis that black elytra have a β-alanine-deficient and dopamine-abundant metabolism, leading to greater melanin (black pigment) production, probably at the expense of cross-linking of cuticular proteins mediated by N-β-alanyldopamine quinone. Copyright © 2010 Elsevier Ltd. All rights reserved.

Evaluation of a Salmonella Strain Lacking the Secondary Messenger C-di-GMP and RpoS as a Live Oral Vaccine

PubMed Central

García, Begoña; Gil, Carmen; García-Ona, Enrique; Burgui, Saioa; Casares, Noelia; Hervás-Stubbs, Sandra; Lasarte, Juan José; Lasa, Iñigo

2016-01-01

Salmonellosis is one of the most important bacterial zoonotic diseases transmitted through the consumption of contaminated food, with chicken and pig related products being key reservoirs of infection. Although numerous studies on animal vaccination have been performed in order to reduce Salmonella prevalence, there is still a need for an ideal vaccine. Here, with the aim of constructing a novel live attenuated Salmonella vaccine candidate, we firstly analyzed the impact of the absence of cyclic-di-GMP (c-di-GMP) in Salmonella virulence. C-di-GMP is an intracellular second messenger that controls a wide range of bacterial processes, including biofilm formation and synthesis of virulence factors, and also modulates the host innate immune response. Our results showed that a Salmonella multiple mutant in the twelve genes encoding diguanylate cyclase proteins that, as a consequence, cannot synthesize c-di-GMP, presents a moderate attenuation in a systemic murine infection model. An additional mutation of the rpoS gene resulted in a synergic attenuating effect that led to a highly attenuated strain, referred to as ΔXIII, immunogenic enough to protect mice against a lethal oral challenge of a S. Typhimurium virulent strain. ΔXIII immunogenicity relied on activation of both antibody and cell mediated immune responses characterized by the production of opsonizing antibodies and the induction of significant levels of IFN-γ, TNF-α, IL-2, IL-17 and IL-10. ΔXIII was unable to form a biofilm and did not survive under desiccation conditions, indicating that it could be easily eliminated from the environment. Moreover, ΔXIII shows DIVA features that allow differentiation of infected and vaccinated animals. Altogether, these results show ΔXIII as a safe and effective live DIVA vaccine. PMID:27537839

Yersinia pestis caf1 variants and the limits of plague vaccine protection.

PubMed

Quenee, Lauriane E; Cornelius, Claire A; Ciletti, Nancy A; Elli, Derek; Schneewind, Olaf

2008-05-01

Yersinia pestis, the highly virulent agent of plague, is a biological weapon. Strategies that prevent plague have been sought for centuries, and immunization with live, attenuated (nonpigmented) strains or subunit vaccines with F1 (Caf1) antigen is considered effective. We show here that immunization with live, attenuated strains generates plague-protective immunity and humoral immune responses against F1 pilus antigen and LcrV. Y. pestis variants lacking caf1 (F1 pili) are not only fully virulent in animal models of bubonic and pneumonic plague but also break through immune responses generated with live, attenuated strains or F1 subunit vaccines. In contrast, immunization with purified LcrV, a protein at the tip of type III needles, generates protective immunity against the wild-type and the fully virulent caf1 mutant strain, in agreement with the notion that LcrV can elicit vaccine protection against both types of virulent plague strains.

The Annona muricata leaf ethanol extract affects mobility and reproduction in mutant strain NB327 Caenorhabditis elegans.

PubMed

Bustos, A V Gualteros; Jiménez, M Gómez; Mora, R M Sánchez

2017-07-01

The C. elegans NB327 mutant strain is characterized for the knockdown of the dic-1 gene. The dic-1 gene is homologous to the dice-1 gene in humans, encoding the protein DICE-1 as a tumor suppressor. Absence or under-regulation of the dice-1 gene can be reflected in lung and prostate cancer [17], [18]. This study evaluated the effect of EEAML on the C. elegans NB327 mutant strain. Phenotypic aspects such as morphology, body length, locomotion, and reproductive behaviour were analyzed. It is important to emphasize that the strain presents a phenotype characteristic with respect to egg laying and hatching. Reported studies showed that Annona muricata extract and its active components evidence anti-cancer and anti-tumor effects, through experimentation in vivo and in vitro models. However, neurotoxicity has been reported as a side effect. The results showed that the mutant strain NB327 was exposed to EEAML (5 mg/ml) concentration, it showed a significant decrease in average locomotion, resulting in 13 undulations in 30 s. This contrasts with the control strain's 17.5 undulations in 30 s. Similarly, the number of progenies was reduced from 188 progenies (control strain) to 114 and 92 progenies at the dose of (1 mg/ml and 5 mg/m) EEAML. The results of this study suggest that EEAML has a possible neurotoxic effect in concentrations equal to or greater than 5 mg/ml. Also, it does not have positive effects on the mutant strain of Caenorhabditis elegans NB327 phenotype.

Effectiveness of Pentavalent Rotavirus Vaccine Against a Diverse Range of Circulating Strains in Nicaragua.

PubMed

Patel, Manish; Pedreira, Cristina; De Oliveira, Lúcia Helena; Tate, Jacqueline; Leshem, Eyal; Mercado, Juan; Umaña, Jazmina; Balmaceda, Angel; Reyes, Martha; Kerin, Tara; McDonald, Sharla; Gentsch, Jon; Bowen, Michael D; Parashar, Umesh

2016-05-01

Because >60 rotavirus strains have been reported worldwide, concerns exist about strain replacement after the introduction of rotavirus vaccines, particularly in developing countries with diverse strains and lower efficacy. We used the case-control design in 4 hospitals in Nicaragua to assess strain-specific vaccine effectiveness (VE) of a pentavalent rotavirus vaccine (RotaTeq) against rotavirus diarrhea. Cases were identified through prospective strain surveillance with reverse transcription-polymerase chain reaction for 3 years among children hospitalized for diarrhea, and controls were children negative for rotavirus. We enrolled 1178 case-patients, 1082 (92%) with G and P typing, and 4927 controls. A different strain predominated each year with increasing age of the vaccine-eligible cohort during the study period: G2P[4] in 2008 (97%; mean age, 11.9 months), G1P[8] in 2009 (55%; mean age, 17.0 months), and G3P[8] in 2010 (78%; mean age, 17.3 months). Overall VE was 45% (95% confidence interval, 25%-59%). Regardless of the strain, VE estimates were 12%-79% lower among children aged ≥12 months relative to those 6-11 months of age. The lower VE for G3P[8] was related to the higher mean age of cases (17.3 months) compared with the G2P[4] strains (11.9 months), with a significant trend (R(2)= 0.819;P< .001) of declining effectiveness with increasing mean age of the cases. Introduction of RotaTeq did not result in sustained emergence of any particular strain in Nicaragua. Variation in strain-specific effectiveness was due to an age-related decline in effectiveness rather than differences in protection against the observed strains. Published by Oxford University Press for the Infectious Diseases Society of America 2016. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Real-time RT-PCR assays to differentiate wild-type group A rotavirus strains from Rotarix(®) and RotaTeq(®) vaccine strains in stool samples.

PubMed

Gautam, Rashi; Esona, Mathew D; Mijatovic-Rustempasic, Slavica; Ian Tam, Ka; Gentsch, Jon R; Bowen, Michael D

2014-01-01

Group A rotaviruses (RVA) are the leading cause of severe diarrhea in young children worldwide. Two live-attenuated RVA vaccines, Rotarix(®) and RotaTeq(®) are recommended by World Health Organization (WHO) for routine immunization of all infants. Rotarix(®) and RotaTeq(®) vaccines have substantially reduced RVA associated mortality but occasionally have been associated with acute gastroenteritis (AGE) cases identified in vaccinees and their contacts. High-throughput assays are needed to monitor the prevalence of vaccine strains in AGE cases and emergence of new vaccine-derived strains following RVA vaccine introduction. In this study, we have developed quantitative real-time RT-PCR (qRT-PCR) assays for detection of Rotarix(®) and RotaTeq(®) vaccine components in stool samples. Real-time RT-PCR assays were designed for vaccine specific targets in the genomes of Rotarix(®) (NSP2, VP4) and RotaTeq(®) (VP6, VP3-WC3, VP3-human) and validated on sequence confirmed stool samples containing vaccine strains, wild-type RVA strains, and RVA-negative stools. For quantification, standard curves were generated using dsRNA transcripts derived from RVA gene segments. Rotarix(®) NSP2 and VP4 qRT-PCR assays exhibited 92-100% sensitivity, 99-100% specificity, 94-105% efficiency, and a limit of detection of 2-3 copies per reaction. RotaTeq(®) VP6, VP3-WC3, and VP3-human qRT-PCR assays displayed 100% sensitivity, 94-100% specificity, 91-102% efficiency and limits of detection of 1 copy, 2 copies, and 140 copies, respectively. These assays permit rapid identification of Rotarix(®) and RotaTeq(®) vaccine components in stool samples from clinical and surveillance studies and will be helpful in determining the frequency of vaccine strain-associated AGE.

Real-time RT-PCR assays to differentiate wild-type group A rotavirus strains from Rotarix® and RotaTeq® vaccine strains in stool samples

PubMed Central

Gautam, Rashi; Esona, Mathew D; Mijatovic-Rustempasic, Slavica; Ian Tam, Ka; Gentsch, Jon R; Bowen, Michael D

2014-01-01

Group A rotaviruses (RVA) are the leading cause of severe diarrhea in young children worldwide. Two live-attenuated RVA vaccines, Rotarix® and RotaTeq® are recommended by World Health Organization (WHO) for routine immunization of all infants. Rotarix® and RotaTeq® vaccines have substantially reduced RVA associated mortality but occasionally have been associated with acute gastroenteritis (AGE) cases identified in vaccinees and their contacts. High-throughput assays are needed to monitor the prevalence of vaccine strains in AGE cases and emergence of new vaccine-derived strains following RVA vaccine introduction. In this study, we have developed quantitative real-time RT-PCR (qRT-PCR) assays for detection of Rotarix® and RotaTeq® vaccine components in stool samples. Real-time RT-PCR assays were designed for vaccine specific targets in the genomes of Rotarix® (NSP2, VP4) and RotaTeq® (VP6, VP3-WC3, VP3-human) and validated on sequence confirmed stool samples containing vaccine strains, wild-type RVA strains, and RVA-negative stools. For quantification, standard curves were generated using dsRNA transcripts derived from RVA gene segments. Rotarix® NSP2 and VP4 qRT-PCR assays exhibited 92–100% sensitivity, 99–100% specificity, 94–105% efficiency, and a limit of detection of 2–3 copies per reaction. RotaTeq® VP6, VP3-WC3, and VP3-human qRT-PCR assays displayed 100% sensitivity, 94–100% specificity, 91–102% efficiency and limits of detection of 1 copy, 2 copies, and 140 copies, respectively. These assays permit rapid identification of Rotarix® and RotaTeq® vaccine components in stool samples from clinical and surveillance studies and will be helpful in determining the frequency of vaccine strain-associated AGE. PMID:24342877

A Novel Non-Replication-Competent Cytomegalovirus Capsid Mutant Vaccine Strategy Is Effective in Reducing Congenital Infection

PubMed Central

Choi, K. Yeon; Root, Matthew

2016-01-01

ABSTRACT Congenital cytomegalovirus (CMV) infection is a leading cause of mental retardation and deafness in newborns. The guinea pig is the only small animal model for congenital CMV infection. A novel CMV vaccine was investigated as an intervention strategy against congenital guinea pig cytomegalovirus (GPCMV) infection. In this disabled infectious single-cycle (DISC) vaccine strategy, a GPCMV mutant virus was used that lacked the ability to express an essential capsid gene (the UL85 homolog GP85) except when grown on a complementing cell line. In vaccinated animals, the GP85 mutant virus (GP85 DISC) induced an antibody response to important glycoprotein complexes considered neutralizing target antigens (gB, gH/gL/gO, and gM/gN). The vaccine also generated a T cell response to the pp65 homolog (GP83), determined via a newly established guinea pig gamma interferon enzyme-linked immunosorbent spot assay. In a congenital infection protection study, GP85 DISC-vaccinated animals and a nonvaccinated control group were challenged during pregnancy with wild-type GPCMV (105 PFU). The pregnant animals carried the pups to term, and viral loads in target organs of pups were analyzed. Based on live pup births in the vaccinated and control groups (94.1% versus 63.6%), the vaccine was successful in reducing mortality (P = 0.0002). Additionally, pups from the vaccinated group had reduced CMV transmission, with 23.5% infected target organs versus 75.9% in the control group. Overall, these preliminary studies indicate that a DISC CMV vaccine strategy has the ability to induce an immune response similar to that of natural virus infection but has the increased safety of a non-replication-competent virus, which makes this approach attractive as a CMV vaccine strategy. IMPORTANCE Congenital CMV infection is a leading cause of mental retardation and deafness in newborns. An effective vaccine against CMV remains an elusive goal despite over 50 years of CMV research. The guinea pig, with

Complete Genomic Sequences of H3N8 Equine Influenza Virus Strains Used as Vaccine Strains in Japan

PubMed Central

Yamanaka, Takashi; Bannai, Hiroshi; Tsujimura, Koji; Kokado, Hiroshi

2018-01-01

ABSTRACT We sequenced the eight segments of influenza A virus strains A/equine/Ibaraki/1/2007 and A/equine/Yokohama/aq13/2010, which are strains of the Florida sublineage clades 1 and 2 of the H3N8 subtype equine influenza virus. These strains have been used as vaccine strains in Japan since 2016 in accordance with World Organization for Animal Health (OIE) recommendations. PMID:29567739

Complete Genomic Sequences of H3N8 Equine Influenza Virus Strains Used as Vaccine Strains in Japan.

PubMed

Nemoto, Manabu; Yamanaka, Takashi; Bannai, Hiroshi; Tsujimura, Koji; Kokado, Hiroshi

2018-03-22

We sequenced the eight segments of influenza A virus strains A/equine/Ibaraki/1/2007 and A/equine/Yokohama/aq13/2010, which are strains of the Florida sublineage clades 1 and 2 of the H3N8 subtype equine influenza virus. These strains have been used as vaccine strains in Japan since 2016 in accordance with World Organization for Animal Health (OIE) recommendations. Copyright © 2018 Nemoto et al.

Variable Virulence and Efficacy of BCG Vaccine Strains in Mice and Correlation With Genome Polymorphisms

PubMed Central

Zhang, Lu; Ru, Huan-wei; Chen, Fu-zeng; Jin, Chun-yan; Sun, Rui-feng; Fan, Xiao-yong; Guo, Ming; Mai, Jun-tao; Xu, Wen-xi; Lin, Qing-xia; Liu, Jun

2016-01-01

Bacille Calmette–Guérin (BCG), an attenuated strain of Mycobacterium bovis, is the only vaccine available for tuberculosis (TB) control. However, BCG is not an ideal vaccine and has two major limitations: BCG exhibits highly variable effectiveness against the development of TB both in pediatric and adult populations and can cause disseminated BCG disease in immunocompromised individuals. BCG comprises a number of substrains that are genetically distinct. Whether and how these genetic differences affect BCG efficacy remains largely unknown. In this study, we performed comparative analyses of the virulence and efficacy of 13 BCG strains, representing different genetic lineages, in SCID and BALB/c mice. Our results show that BCG strains of the DU2 group IV (BCG-Phipps, BCG-Frappier, BCG-Pasteur, and BCG-Tice) exhibit the highest levels of virulence, and BCG strains of the DU2 group II (BCG-Sweden, BCG-Birkhaug) are among the least virulent group. These distinct levels of virulence may be explained by strain-specific duplications and deletions of genomic DNA. There appears to be a general trend that more virulent BCG strains are also more effective in protection against Mycobacterium tuberculosis challenge. Our findings have important implications for current BCG vaccine programs and for future TB vaccine development. PMID:26643797

Variable Virulence and Efficacy of BCG Vaccine Strains in Mice and Correlation With Genome Polymorphisms.

PubMed

Zhang, Lu; Ru, Huan-Wei; Chen, Fu-Zeng; Jin, Chun-Yan; Sun, Rui-Feng; Fan, Xiao-Yong; Guo, Ming; Mai, Jun-Tao; Xu, Wen-Xi; Lin, Qing-Xia; Liu, Jun

2016-02-01

Bacille Calmette-Guérin (BCG), an attenuated strain of Mycobacterium bovis, is the only vaccine available for tuberculosis (TB) control. However, BCG is not an ideal vaccine and has two major limitations: BCG exhibits highly variable effectiveness against the development of TB both in pediatric and adult populations and can cause disseminated BCG disease in immunocompromised individuals. BCG comprises a number of substrains that are genetically distinct. Whether and how these genetic differences affect BCG efficacy remains largely unknown. In this study, we performed comparative analyses of the virulence and efficacy of 13 BCG strains, representing different genetic lineages, in SCID and BALB/c mice. Our results show that BCG strains of the DU2 group IV (BCG-Phipps, BCG-Frappier, BCG-Pasteur, and BCG-Tice) exhibit the highest levels of virulence, and BCG strains of the DU2 group II (BCG-Sweden, BCG-Birkhaug) are among the least virulent group. These distinct levels of virulence may be explained by strain-specific duplications and deletions of genomic DNA. There appears to be a general trend that more virulent BCG strains are also more effective in protection against Mycobacterium tuberculosis challenge. Our findings have important implications for current BCG vaccine programs and for future TB vaccine development.

Rational Design of a Live Attenuated Dengue Vaccine: 2′-O-Methyltransferase Mutants Are Highly Attenuated and Immunogenic in Mice and Macaques

PubMed Central

Chang, David C.; Zhang, Bo; Balakrishnan, Thavamalar; Toh, Ying-Xiu; Jiang, Tao; Li, Shi-Hua; Deng, Yong-Qiang; Ellis, Brett R.; Ellis, Esther M.; Poidinger, Michael; Zolezzi, Francesca; Qin, Cheng-Feng; Shi, Pei-Yong; Fink, Katja

2013-01-01

Dengue virus is transmitted by Aedes mosquitoes and infects at least 100 million people every year. Progressive urbanization in Asia and South-Central America and the geographic expansion of Aedes mosquito habitats have accelerated the global spread of dengue, resulting in a continuously increasing number of cases. A cost-effective, safe vaccine conferring protection with ideally a single injection could stop dengue transmission. Current vaccine candidates require several booster injections or do not provide protection against all four serotypes. Here we demonstrate that dengue virus mutants lacking 2′-O-methyltransferase activity are highly sensitive to type I IFN inhibition. The mutant viruses are attenuated in mice and rhesus monkeys and elicit a strong adaptive immune response. Monkeys immunized with a single dose of 2′-O-methyltransferase mutant virus showed 100% sero-conversion even when a dose as low as 1,000 plaque forming units was administrated. Animals were fully protected against a homologous challenge. Furthermore, mosquitoes feeding on blood containing the mutant virus were not infected, whereas those feeding on blood containing wild-type virus were infected and thus able to transmit it. These results show the potential of 2′-O-methyltransferase mutant virus as a safe, rationally designed dengue vaccine that restrains itself due to the increased susceptibility to the host's innate immune response. PMID:23935499

The live attenuated Actinobacillus pleuropneumoniae triple-deletion mutant ΔapxIC ΔapxIIC ΔapxIV-ORF1 strain, SLW05, Immunizes pigs against lethal challenge with Haemophilus parasuis.

PubMed

Fu, Shulin; Ou, Jiwen; Zhang, Minmin; Xu, Juan; Liu, Huazhen; Liu, Jinlin; Yuan, Fangyan; Chen, Huanchun; Bei, Weicheng

2013-02-01

Haemophilus parasuis and Actinobacillus pleuropneumoniae both belong to the family Pasteurellaceae and are major respiratory pathogens that cause large economic losses in the pig industry worldwide. We previously constructed an attenuated A. pleuropneumoniae serovar 1 live vaccine prototype, SLW05 (ΔapxIC ΔapxIIC ΔapxIV-ORF1), which is able to produce nontoxic but immunogenic ApxIA, ApxIIA, and ApxIVA. This triple-deletion mutant strain was shown to elicit protective immunity against virulent A. pleuropneumoniae. In the present study, we investigated whether immunization with SLW05 could also protect against lethal challenge with virulent H. parasuis SH0165 (serovar 5) or MD0322 (serovar 4). The SLW05 strain was found to elicit a strong humoral antibody response in pigs and to confer significant protection against challenge with a lethal dose of H. parasuis SH0165 or MD0322. IgG subtype analysis revealed that SLW05 induces a bias toward a Th1-type immune response and stimulates interleukin 2 (IL-2) and gamma interferon (IFN-γ) production. Moreover, antisera from SLW05-vaccinated pigs efficiently inhibited both A. pleuropneumoniae and H. parasuis growth in a whole-blood assay. This is the first report that a live attenuated A. pleuropneumoniae vaccine with SLW05 can protect against lethal H. parasuis infection, which provides a novel approach for developing an attenuated H. parasuis vaccine.

Safety of classical swine fever virus vaccine strain LOM in pregnant sows and their offspring.

PubMed

Lim, Seong-In; Song, Jae-Young; Kim, Jaejo; Hyun, Bang-Hun; Kim, Ha-Young; Cho, In-Soo; Kim, Byounghan; Woo, Gye-Hyeong; Lee, Jung-Bok; An, Dong-Jun

2016-04-12

The present study aimed to evaluate the safety of the classical swine fever virus (CSFV) vaccine strain LOM in pregnant sows. Pregnant sows with free CSFV antibody were inoculated with a commercial LOM vaccine during early pregnancy (day 38; n=3) or mid-pregnancy (days 49-59; n=11). In pregnant sows vaccinated during the early stages of gestation, abortion (day 109) was observed in one case, with two stillbirths and seven mummified fetuses. The viability of live-born piglets was 34.9% in sows vaccinated during mid-pregnancy compared with 81.8% in the control group. Post-mortem examination of the organs of the sows and piglets did not reveal any pathological lesions caused by CSFV; however, CSFV RNA was detected in the organs of several vaccinated sows and their litters. The LOM strain was transmitted from sows with free CSFV antibody to their fetus, but did not appear to induce immune tolerance in the offspring from vaccinated pregnant sows. Side effects were not observed in pregnant sows with antibody to the LOM strain: transmission from sow to their litters and stillbirth or mummified fetuses. The LOM strain may induce sterile immunity and provide rapid, long-lasting, and complete protection against CSFV; however, it should be contraindicated in pregnant sows due to potential adverse effects in pregnant sows with free CSFV antibody. Copyright © 2016 Elsevier Ltd. All rights reserved.

Efficacy of single calfhood vaccination of elk with Brucella abortus strain 19

USGS Publications Warehouse

Roffe, T.J.; Jones, L.C.; Coffin, K.; Drew, M.L.; Sweeney, Steven J.; Hagius, S.D.; Elzer, P.H.; Davis, D.

2004-01-01

Brucellosis has been eradicated from cattle in the states of Wyoming, Montana, and Idaho, USA. However, free-ranging elk (Cervus elaphus) that use feedgrounds in the Greater Yellowstone Area (GYA) and bison (Bison bison) in Yellowstone and Grand Teton national parks still have high seroprevalence to the disease and have caused loss of brucellosis-free status in Wyoming. Management tools to control or eliminate the disease are limited; however, wildlife vaccination is among the methods currently used by wildlife managers in Wyoming. We conducted a controlled challenge study of single calfhood vaccination. Elk calves, caught in January and February of 1999 and 2000 and acclimated to captivity for 3 weeks, were randomly assigned to control or vaccinate groups. The vaccinate groups received Brucetta abortus vaccine strain 19 (S19) by hand-delivered intramuscular injection. Calves were raised to adulthood and bred at either 2.5 or 3.5 years of age for 2000 and 1999 captures, respectively. Eighty-nine (44 controls, 45 vaccinates) pregnant elk entered the challenge portion of the study. We challenged elk at mid-gestation with pathogenic B. abortus strain 2308 by intraconjunctival instillation. Abortion occurred in significantly more (P = 0.002) controls (42; 93%) than vaccinates (32; 71%), and vaccine protected 25% of the vaccinate group. We used Brucella culture of fetus/calf tissues to determine the efficacy of vaccination for preventing infection, and we found that the number of infected fetuses/calves did not differ between controls and vaccinates (P = 0.14). Based on these data, single calfhood vaccination with S19 has low efficacy, will likely have only little to moderate effect on Brucella prevalence in elk, and is unlikely to eradicate the disease in wildlife of the GYA.

Mutant strains of Spirulina (Arthrospira) platensis to increase the efficiency of micro-ecological life support systems

NASA Astrophysics Data System (ADS)

Brown, Igor

The European Micro-Ecological Life Support System Alternative (MELiSSA) is an advanced idea for organizing a bioregenerative system for long term space flights and extraterrestrial settlements (Hendrickx, De Wever et al., 2005). Despite the hostility of both lunar and Martian environments to unprotected life, it seems possible to cultivate photosynthetic bacteria using closed bioreactors illuminated and heated by solar energy. Such reactors might be employed in critical processes, e.g. air revitalization, foodcaloric and protein source, as well as an immunomodulators production. The MELiSSA team suggested cyanobacterium Spirulina as most appropriate agent to revitalize air and produce a simple "fast" food. This is right suggestion because Spirulina was recently shown to be an oxygenic organism with the highest level of O2 production per unit mass (Ananyev et al., 2005). Chemical composition of Spirulina includes proteins (55Aiming to make Spirulina cultivation in life support systems like MELiSSA more efficient, we selected Spirulina mutant strains with increased fraction of methionine in the biomass of this cyanobacterium and compared the effect of parental wild strain of Spirulina and its mutants on the tendency of such experimental illnesses as radiationinduced lesions and hemolythic anemia. Results: It was found that mutant strains 198B and 27G contain higher quantities of total protein, essential amino acids, c-phycocyanin, allophycocyanin and chlorophyll a than parental wild strain of S. platensis. The strain 198B is also characterized with increased content of carotenoids. Revealed biochemical peculiarities of mutant strains suggest that these strains can serve as an additional source of essential amino acids as well as phycobiliproteins and carotenoids for the astronauts. Feeding animals suffering from radiation-induced lesions, c-phycocyanin, extracted from strain 27G, led to a correction in deficient dehydrogenase activity and energy-rich phosphate levels

Genetic and antigenic characterisation of serotype A FMD viruses from East Africa to select new vaccine strains

PubMed Central

Bari, Fufa D.; Parida, Satya; Tekleghiorghis, Tesfaalem; Dekker, Aldo; Sangula, Abraham; Reeve, Richard; Haydon, Daniel T.; Paton, David J.; Mahapatra, Mana

2014-01-01

Vaccine strain selection for emerging foot-and-mouth disease virus (FMDV) outbreaks in enzootic countries can be addressed through antigenic and genetic characterisation of recently circulating viruses. A total of 56 serotype A FMDVs isolated between 1998 and 2012, from Central, East and North African countries were characterised antigenically by virus neutralisation test using antisera to three existing and four candidate vaccine strains and, genetically by characterising the full capsid sequence data. A Bayesian analysis of the capsid sequence data revealed the viruses to be of either African or Asian topotypes with subdivision of the African topotype viruses into four genotypes (Genotypes I, II, IV and VII). The existing vaccine strains were found to be least cross-reactive (good matches observed for only 5.4–46.4% of the sampled viruses). Three bovine antisera, raised against A-EA-2007, A-EA-1981 and A-EA-1984 viruses, exhibited broad cross-neutralisation, towards more than 85% of the circulating viruses. Of the three vaccines, A-EA-2007 was the best showing more than 90% in-vitro cross-protection, as well as being the most recent amongst the vaccine strains used in this study. It therefore appears antigenically suitable as a vaccine strain to be used in the region in FMD control programmes. PMID:25171846

Strain Selection for Generation of O-Antigen-Based Glycoconjugate Vaccines against Invasive Nontyphoidal Salmonella Disease

PubMed Central

Saul, Allan; MacLennan, Calman A.; Micoli, Francesca; Rondini, Simona

2015-01-01

Nontyphoidal Salmonellae, principally S. Typhimurium and S. Enteritidis, are a major cause of invasive bloodstream infections in sub-Saharan Africa with no vaccine currently available. Conjugation of lipopolysaccharide O-antigen to a carrier protein constitutes a promising vaccination strategy. Here we describe a rational process to select the most appropriate isolates of Salmonella as source of O-antigen for developing a bivalent glycoconjugate vaccine. We screened a library of 30 S. Typhimurium and 21 S. Enteritidis in order to identify the most suitable strains for large scale O-antigen production and generation of conjugate vaccines. Initial screening was based on growth characteristics, safety profile of the isolates, O-antigen production, and O-antigen characteristics in terms of molecular size, O-acetylation and glucosylation level and position, as determined by phenol sulfuric assay, NMR, HPLC-SEC and HPAEC-PAD. Three animal isolates for each serovar were identified and used to synthesize candidate glycoconjugate vaccines, using CRM197 as carrier protein. The immunogenicity of these conjugates and the functional activity of the induced antibodies was investigated by ELISA, serum bactericidal assay and flow cytometry. S. Typhimurium O-antigen showed high structural diversity, including O-acetylation of rhamnose in a Malawian invasive strain generating a specific immunodominant epitope. S. Typhimurium conjugates provoked an anti-O-antigen response primarily against the O:5 determinant. O-antigen from S. Enteritidis was structurally more homogeneous than from S. Typhimurium, and no idiosyncratic antibody responses were detected for the S. Enteritidis conjugates. Of the three initially selected isolates, two S. Typhimurium (1418 and 2189) and two S. Enteritidis (502 and 618) strains generated glycoconjugates able to induce high specific antibody levels with high breadth of serovar-specific strain coverage, and were selected for use in vaccine production. The

[Comparative analysis on the complete genome sequence of mumps epidemic strain and mumps vaccine strain S79 isolated in Zhejiang province, China between year 2005 and 2010].

PubMed

Zhang, Dong-Yan; Feng, Yan; Zhong, Shu-Ling; Lu, Yi-Yu; Zhuang, Fang-Cheng; Xu, Chang-Ping

2012-03-01

To compare the differences in the complete genome sequence between mumps epidemic strain and mumps vaccine strain S79 isolated in Zhejiang province. A total of 4 mumps epidemic strains, which were separated from Zhejiang province during 2005 to 2010, named as ZJ05-1, ZJ06-3, ZJ08-1 and ZJ10-1 were selected in the study. The complete genome sequences were amplified using RT-PCR. The genetic differences between vaccine strain S79 and other genotype strains were compared; while the genetic-distance was calculated and the evolution was analyzed. The biggest difference between the 4 epidemic strains and the vaccine strain S79 was found on the membrane associated protein gene; whose average nucleotide differential number was 42.5 +/- 3.0 and the average variant ratio was 13.6%; while the mean amino acid differential number was 12.8 +/- 1.5 and the average variant ratio was 22.4%. The smallest difference among the 4 epidemic strains and the vaccine strain was found in stromatin genes, whose average nucleotide differential number was 73.8 +/- 2.5 and the average variant ratio was 5.9%; while the mean amino acid differential number was 3.0 +/- 0.8 and the average variant ratio was 0.8%. The dn/ds value of the stromatin genes of the 4 epidemic strains reached the highest, as 0.6526; but without any positive pressure (dn/ds < 1, chi2 = 0.87, P > 0.05). There were mutations happened on the known antigen epitope, as 8th amino acid of membrane associated protein genes and on the 336th and 356th amino acid of hemagglutinin/neuraminidase proteins. Compared with the vaccine strain, the glycosylation sites of ZJ05-1, ZJ06-3, ZJ08-1 and ZJ10-1 increased 1, 1, 2 and 2 respectively. The complete amino acid sequence of all strains showed that there were 17 characteristic sites found on the genotype-F mumps strain. Within the complete genome, the genetic-distance between epidemic strains and vaccine strains in Zhejiang province (0.071) was significantly larger than the genetic

Brucella abortus Cyclic β-1,2-Glucan Mutants Have Reduced Virulence in Mice and Are Defective in Intracellular Replication in HeLa Cells

PubMed Central

Briones, Gabriel; Iñón de Iannino, Nora; Roset, Mara; Vigliocco, Ana; Paulo, Patricia Silva; Ugalde, Rodolfo A.

2001-01-01

Null cyclic β-1,2-glucan synthetase mutants (cgs mutants) were obtained from Brucella abortus virulent strain 2308 and from B. abortus attenuated vaccinal strain S19. Both mutants show greater sensitivity to surfactants like deoxycholic acid, sodium dodecyl sulfate, and Zwittergent than the parental strains, suggesting cell surface alterations. Although not to the same extent, both mutants display reduced virulence in mice and defective intracellular multiplication in HeLa cells. The B. abortus S19 cgs mutant was completely cleared from the spleens of mice after 4 weeks, while the 2308 mutant showed a 1.5-log reduction of the number of brucellae isolated from the spleens after 12 weeks. These results suggest that cyclic β-1,2-glucan plays an important role in the residual virulence of the attenuated B. abortus S19 strain. Although the cgs mutant was cleared from the spleens earlier than the wild-type parental strain (B. abortus S19) and produced less inflammatory response, its ability to confer protection against the virulent strain B. abortus 2308 was fully retained. Equivalent levels of induction of spleen gamma interferon mRNA and anti-lipopolysaccharide (LPS) of immunoglobulin G2a (IgG2a) subtype antibodies were observed in mice injected with B. abortus S19 or the cgs mutant. However, the titer of anti-LPS antibodies of the IgG1 subtype induced by the cgs mutant was lower than that observed with the parental S19 strain, thus suggesting that the cgs mutant induces a relatively exclusive Th1 response. PMID:11401996

Oral Vaccination against Bubonic Plague Using a Live Avirulent Yersinia pseudotuberculosis Strain ▿

PubMed Central

Blisnick, Thierry; Ave, Patrick; Huerre, Michel; Carniel, Elisabeth; Demeure, Christian E.

2008-01-01

We evaluated the possibility of using Yersinia pseudotuberculosis as a live vaccine against plague because it shares high genetic identity with Y. pestis while being much less virulent, genetically much more stable, and deliverable orally. A total of 41 Y. pseudotuberculosis strains were screened by PCR for the absence of the high pathogenicity island, the superantigens YPM, and the type IV pilus and the presence of the pYV virulence plasmid. One strain (IP32680) fulfilled these criteria. This strain was avirulent in mice upon intragastric or subcutaneous inoculation and persisted for 2 months in the mouse intestine without clinical signs of disease. IP32680 reached the mesenteric lymph nodes, spleen, and liver without causing major histological lesions and was cleared after 13 days. The antibodies produced in vaccinated animals recognized both Y. pseudotuberculosis and Y. pestis antigens efficiently. After a subcutaneous challenge with Y. pestis CO92, bacteria were found in low amounts in the organs and rarely in the blood of vaccinated animals. One oral IP32680 inoculation protected 75% of the mice, and two inoculations induced much higher antibody titers and protected 88% of the mice. Our results thus validate the concept that an attenuated Y. pseudotuberculosis strain can be an efficient, inexpensive, safe, and easy-to-produce live vaccine for oral immunization against bubonic plague. PMID:18505804

Strain-specific Plasmodium falciparum growth inhibition among Malian children immunized with a blood-stage malaria vaccine.

PubMed

Laurens, Matthew B; Kouriba, Bourema; Bergmann-Leitner, Elke; Angov, Evelina; Coulibaly, Drissa; Diarra, Issa; Daou, Modibo; Niangaly, Amadou; Blackwelder, William C; Wu, Yukun; Cohen, Joe; Ballou, W Ripley; Vekemans, Johan; Lanar, David E; Dutta, Sheetij; Diggs, Carter; Soisson, Lorraine; Heppner, D Gray; Doumbo, Ogobara K; Plowe, Christopher V; Thera, Mahamadou A

2017-01-01

The blood-stage malaria vaccine FMP2.1/AS02A, comprised of recombinant Plasmodium falciparum apical membrane antigen 1 (AMA1) and the adjuvant system AS02A, had strain-specific efficacy against clinical malaria caused by P. falciparum with the vaccine strain 3D7 AMA1 sequence. To evaluate a potential correlate of protection, we measured the ability of participant sera to inhibit growth of 3D7 and FVO strains in vitro using high-throughput growth inhibition assay (GIA) testing. Sera from 400 children randomized to receive either malaria vaccine or a control rabies vaccine were assessed at baseline and over two annual malaria transmission seasons after immunization. Baseline GIA against vaccine strain 3D7 and FVO strain was similar in both groups, but more children in the malaria vaccine group than in the control group had 3D7 and FVO GIA activity ≥15% 30 days after the last vaccination (day 90) (49% vs. 16%, p<0.0001; and 71.8% vs. 60.4%, p = 0.02). From baseline to day 90, 3D7 GIA in the vaccine group was 7.4 times the mean increase in the control group (p<0.0001). In AMA1 vaccinees, 3D7 GIA activity subsequently returned to baseline one year after vaccination (day 364) and did not correlate with efficacy in the extended efficacy time period to day 730. In Cox proportional hazards regression models with time-varying covariates, there was a slight suggestion of an association between 3D7 GIA activity and increased risk of clinical malaria between day 90 and day 240. We conclude that vaccination with this AMA1-based malaria vaccine increased inhibition of parasite growth, but this increase was not associated with allele-specific efficacy in the first malaria season. These results provide a framework for testing functional immune correlates of protection against clinical malaria in field trials, and will help to guide similar analyses for next-generation malaria vaccines. Clinical trials registry: This clinical trial was registered on clinicaltrials.gov, registry

Strain-specific Plasmodium falciparum growth inhibition among Malian children immunized with a blood-stage malaria vaccine

PubMed Central

Kouriba, Bourema; Bergmann-Leitner, Elke; Angov, Evelina; Coulibaly, Drissa; Diarra, Issa; Daou, Modibo; Niangaly, Amadou; Blackwelder, William C.; Wu, Yukun; Cohen, Joe; Ballou, W. Ripley; Vekemans, Johan; Lanar, David E.; Dutta, Sheetij; Diggs, Carter; Soisson, Lorraine; Heppner, D. Gray; Doumbo, Ogobara K.; Plowe, Christopher V.; Thera, Mahamadou A.

2017-01-01

The blood-stage malaria vaccine FMP2.1/AS02A, comprised of recombinant Plasmodium falciparum apical membrane antigen 1 (AMA1) and the adjuvant system AS02A, had strain-specific efficacy against clinical malaria caused by P. falciparum with the vaccine strain 3D7 AMA1 sequence. To evaluate a potential correlate of protection, we measured the ability of participant sera to inhibit growth of 3D7 and FVO strains in vitro using high-throughput growth inhibition assay (GIA) testing. Sera from 400 children randomized to receive either malaria vaccine or a control rabies vaccine were assessed at baseline and over two annual malaria transmission seasons after immunization. Baseline GIA against vaccine strain 3D7 and FVO strain was similar in both groups, but more children in the malaria vaccine group than in the control group had 3D7 and FVO GIA activity ≥15% 30 days after the last vaccination (day 90) (49% vs. 16%, p<0.0001; and 71.8% vs. 60.4%, p = 0.02). From baseline to day 90, 3D7 GIA in the vaccine group was 7.4 times the mean increase in the control group (p<0.0001). In AMA1 vaccinees, 3D7 GIA activity subsequently returned to baseline one year after vaccination (day 364) and did not correlate with efficacy in the extended efficacy time period to day 730. In Cox proportional hazards regression models with time-varying covariates, there was a slight suggestion of an association between 3D7 GIA activity and increased risk of clinical malaria between day 90 and day 240. We conclude that vaccination with this AMA1-based malaria vaccine increased inhibition of parasite growth, but this increase was not associated with allele-specific efficacy in the first malaria season. These results provide a framework for testing functional immune correlates of protection against clinical malaria in field trials, and will help to guide similar analyses for next-generation malaria vaccines. Clinical trials registry: This clinical trial was registered on clinicaltrials.gov, registry

Proteomic Analysis of Anti-Cancerous Scopularide Production by a Marine Microascus brevicaulis Strain and Its UV Mutant.

PubMed

Kramer, Annemarie; Beck, Hans Christian; Kumar, Abhishek; Kristensen, Lars Peter; Imhoff, Johannes F; Labes, Antje

2015-01-01

The marine fungus Microascus brevicaulis strain LF580 is a non-model secondary metabolite producer with high yields of the two secondary metabolites scopularides A and B, which exhibit distinct activities against tumour cell lines. A mutant strain was obtained using UV mutagenesis, showing faster growth and differences in pellet formation besides higher production levels. Here, we show the first proteome study of a marine fungus. Comparative proteomics were applied to gain deeper understanding of the regulation of production and of the physiology of the wild type strain and its mutant. For this purpose, an optimised protein extraction protocol was established. In total, 4759 proteins were identified. The central metabolic pathway of strain LF580 was mapped using the KEGG pathway analysis and GO annotation. Employing iTRAQ labelling, 318 proteins were shown to be significantly regulated in the mutant strain: 189 were down- and 129 upregulated. Proteomics are a powerful tool for the understanding of regulatory aspects: The differences on proteome level could be attributed to limited nutrient availability in the wild type strain due to a strong pellet formation. This information can be applied for optimisation on strain and process level. The linkage between nutrient limitation and pellet formation in the non-model fungus M. brevicaulis is in consensus with the knowledge on model organisms like Aspergillus niger and Penicillium chrysogenum.

Proteomic Analysis of Anti-Cancerous Scopularide Production by a Marine Microascus brevicaulis Strain and Its UV Mutant

PubMed Central

Kramer, Annemarie; Beck, Hans Christian; Kumar, Abhishek; Kristensen, Lars Peter; Imhoff, Johannes F.; Labes, Antje

2015-01-01

The marine fungus Microascus brevicaulis strain LF580 is a non-model secondary metabolite producer with high yields of the two secondary metabolites scopularides A and B, which exhibit distinct activities against tumour cell lines. A mutant strain was obtained using UV mutagenesis, showing faster growth and differences in pellet formation besides higher production levels. Here, we show the first proteome study of a marine fungus. Comparative proteomics were applied to gain deeper understanding of the regulation of production and of the physiology of the wild type strain and its mutant. For this purpose, an optimised protein extraction protocol was established. In total, 4759 proteins were identified. The central metabolic pathway of strain LF580 was mapped using the KEGG pathway analysis and GO annotation. Employing iTRAQ labelling, 318 proteins were shown to be significantly regulated in the mutant strain: 189 were down- and 129 upregulated. Proteomics are a powerful tool for the understanding of regulatory aspects: The differences on proteome level could be attributed to limited nutrient availability in the wild type strain due to a strong pellet formation. This information can be applied for optimisation on strain and process level. The linkage between nutrient limitation and pellet formation in the non-model fungus M. brevicaulis is in consensus with the knowledge on model organisms like Aspergillus niger and Penicillium chrysogenum. PMID:26460745

Vi-CRM 197 as a new conjugate vaccine against Salmonella Typhi.

PubMed

Micoli, F; Rondini, S; Pisoni, I; Proietti, D; Berti, F; Costantino, P; Rappuoli, R; Szu, S; Saul, A; Martin, L B

2011-01-17

An efficacious, low cost vaccine against typhoid fever, especially for young children, would make a major impact on disease burden in developing countries. The virulence capsular polysaccharide of Salmonella Typhi (Vi) coupled to recombinant mutant Pseudomonas aeruginosa exoprotein A (Vi-rEPA) has been shown to be highly efficacious. We investigated the use of carrier proteins included in infant vaccines, standardized the conjugation process and developed key assays required for routine lot release at production scale. Vi from a BSL1 organism, Citrobacter freundii, strain WR7011, was used as an alternative to Vi from S. Typhi. We showed that Vi conjugated to CRM(197), a non-toxic mutant of diphtheria toxin, widely used in commercial vaccines, was produced at high yield. Vi-CRM(197) proved immunogenic in animal studies, even without adjuvant. Thus, Vi-CRM(197) appears to be a suitable candidate for the development of a commercially viable, effective typhoid vaccine for developing countries. Copyright © 2010 Elsevier Ltd. All rights reserved.

Enhancement of safety and immunogenicity of the Chinese Hu191 measles virus vaccine by alteration of the S-adenosylmethionine (SAM) binding site in the large polymerase protein.

PubMed

Wang, Yilong; Liu, Rongxian; Lu, Mijia; Yang, Yingzhi; Zhou, Duo; Hao, Xiaoqiang; Zhou, Dongming; Wang, Bin; Li, Jianrong; Huang, Yao-Wei; Zhao, Zhengyan

2018-05-01

The live-attenuated measles virus (MV) vaccine based on the Hu191 strain has played a significant role in controlling measles in China. However, it has considerable adverse effects that may cause public health burden. We hypothesize that the safety and efficacy of MV vaccine can be improved by altering the S-adenosylmethionine (SAM) binding site in the conserved region VI of the large polymerase protein. To test this hypothesis, we established an efficient reverse genetics system for the rMV-Hu191 strain and generated two recombinant MV-Hu191 carrying mutations in the SAM binding site. These two mutants grew to high titer in Vero cells, were genetically stable, and were significantly more attenuated in vitro and in vivo compared to the parental rMV-Hu191 vaccine strain. Importantly, both MV-Hu191 mutants triggered a higher neutralizing antibody than rMV-Hu191 vaccine and provided complete protection against MV challenge. These results demonstrate its potential for an improved MV vaccine candidate. Copyright © 2018 Elsevier Inc. All rights reserved.

Evaluation of fusion protein cleavage site sequences of Newcastle disease virus in genotype matched vaccines.

PubMed

Kim, Shin-Hee; Chen, Zongyan; Yoshida, Asuka; Paldurai, Anandan; Xiao, Sa; Samal, Siba K

2017-01-01

Newcastle disease virus (NDV) causes a devastating poultry disease worldwide. Frequent outbreaks of NDV in chickens vaccinated with conventional live vaccines suggest a need to develop new vaccines that are genetically matched against circulating NDV strains, such as the genotype V virulent strains currently circulating in Mexico and Central America. In this study, a reverse genetics system was developed for the virulent NDV strain Mexico/01/10 strain and used to generate highly attenuated vaccine candidates by individually modifying the cleavage site sequence of fusion (F) protein. The cleavage site sequence of parental virus was individually changed to those of the avirulent NDV strain LaSota and other serotypes of avian paramyxoviruses (APMV serotype-2, -3, -4, -6, -7, -8, and -9). In general, these mutations affected cell-to-cell fusion activity in vitro and the efficiency of the F protein cleavage and made recombinant Mexico/01/10 (rMex) virus highly attenuated in chickens. When chickens were immunized with the rMex mutant viruses and challenged with the virulent parent virus, there was reduced challenge virus shedding compared to birds immunized with the heterologous vaccine strain LaSota. Among the vaccine candidates, rMex containing the cleavage site sequence of APMV-2 induced the highest neutralizing antibody titer and completely protected chickens from challenge virus shedding. These results show the role of the F protein cleavage site sequence of each APMV type in generating genotype V-matched vaccines and the efficacy of matched vaccine strains to provide better protection against NDV strains currently circulating in Mexico.

Comparative analysis on inactivation kinetics of between piezotolerant and piezosensitive mutant strains of Saccharomyces cerevisiae under combinations of high hydrostatic pressure and temperature.

PubMed

Nomura, Kazuki; Kuwabara, Yuki; Kuwabara, Wataru; Takahashi, Hiroyuki; Nakajima, Kanako; Hayashi, Mayumi; Iguchi, Akinori; Shigematsu, Toru

2017-12-01

We previously obtained a pressure-tolerant (piezotolerant) and a pressure sensitive (piezosensitive) mutant strain, under ambient temperature, from Saccharomyces cerevisiae strain KA31a. The inactivation kinetics of these mutants were analyzed at 150 to 250MPa with 4 to 40°C. By a multiple regression analysis, the pressure and temperature dependency of the inactivation rate constants k values of both mutants, as well as the parent strain KA31a, were well approximated with high correlation coefficients (0.92 to 0.95). For both mutants, as well as strain KA31a, the lowest k value was shown at a low pressure levels with around ambient temperature. The k value approximately increased with increase in pressure level, and with increase and decrease in temperature. The piezosensitive mutant strain a924E1 showed piezosensitivity at all pressure and temperature levels, compared with the parent strain KA31a. In contrast, the piezotolerant mutant strain a2568D8 showed piezotolerance at 4 to 20°C, but did not show significant piezotolerance at 40°C. These results of the variable influence of temperature on pressure inactivation of these strains would be important for better understanding of piezosensitive and piezotolerant mechanisms, as well as the pressure inactivation mechanism of S. cerevisiae. Copyright © 2017 Elsevier B.V. All rights reserved.

[The isolation and characteristics of mutants of the Saccharopolyspora erythraea strain resistant to thiostrepton].

PubMed

Nastasiak, I N; Fedorenko, V A; Danilenko, V N

1997-01-01

The formation of thiostreptone resistant spontaneous and nitrosoguanidine-induced mutants in the erythromycin-producing organism Saccharopolyspora erythraea was investigated. The investigated collection of the mutants was heterogeneous by the level of the thiostreptone resistance (2.5 to 20 micrograms/ml). The thiostreptone resistance mutations had a pleiotropic effect: 17 per cent of the mutants was characterized by the growth thermosensitivity and 26 and 5.8 per cent of the mutants were characterized by loss of the ability to form melanine and aerial mycelium respectively. Such phenotypes were most frequent in the mutants resistant to low concentrations of thiostreptone (2 to 5 micrograms/ml). The absolute majority of the isolated thiostreptone resistant mutants was unstable and formed both the antibiotic resistant and the antibiotic sensitive clones. The greatest portion of the strains with high antibiotic activity (20 per cent) was detected among the S. erythraea spontaneous mutants on the medium with 2.5 micrograms/ ml of thiostreptone. It was shown that the instability of the high antibiotic activity in the mutants was associated with loss of the thiostreptone resistance property.

[Antigenic determination of human anti-rabies vaccine against viral street strains common in the wild animal population in Poland].

PubMed

Seroka, D

1994-01-01

The aim of the study was to compare the antigen properties of a vaccine strain with street strains isolated from various animal hosts throughout the country. Investigation was carried out using monoclonal antibodies against NC protein. Also, two tests were carried out: the modified NIH test for potency and the neutralization test using the sera of people vaccinated against rabies (PM vaccine strain). The investigated street strains were used in both tests as the challenge viruses. A suspension of these strains diluted five times made it possible to avoid extreme values of animal survival (0% or 100%) what, consequently, made calculation of the LD50 value easier. A different rabies virus serotype (EBLI virus) in the population of insectivore bats Eptesicus serotinus and antigen variants within the first serotype, having common epitopes with strains of the vaccine virus SAD B19 and the polar rabies virus, were found to be present throughout the country. The concentrated and purified vaccine containing the PM virus did not protect mice against infection with strains of viruses isolated from bats (protection index 10 and lower). For the remaining strains, depending on the animal source of their isolation, the protection index ranged from 10 to 1000 and higher. The properties neutralizing a dose of 5 i.u./ml of serum from the subject inoculated with the vaccine containing the PM strain were similar for all the investigated strains; 0,5 i.u./ml did not neutralize the strain isolated from a racoon dog.

Safety and efficacy of an attenuated Chinese QX-like infectious bronchitis virus strain as a candidate vaccine.

PubMed

Zhao, Ye; Cheng, Jin-long; Liu, Xiao-yu; Zhao, Jing; Hu, Yan-xin; Zhang, Guo-zhong

2015-10-22

Infectious bronchitis (IB) is a highly contagious respiratory and urogenital disease of chickens caused by infectious bronchitis virus (IBV). This disease is of considerable economic importance and is primarily controlled through biosecurity and immunization with live attenuated and inactivated IB vaccines of various serotypes. In the present study, we tested the safety and efficacy of an attenuated predominant Chinese QX-like IBV strain. The results revealed that the attenuated strain has a clear decrease in pathogenicity for specific-pathogen-free (SPF) chickens compared with the parent strain. Strain YN-inoculated birds had clinical signs of varying severity with 30% mortality, while the attenuated group appeared healthy, with less tissue damage. The attenuated strain also had relatively low tissue replication rates and higher antibody levels. The superior protective efficacy of the attenuated strain was observed when vaccinated birds were challenged with a homologous or heterologous field IBV strain, indicating the potential of the attenuated YN (aYN) as a vaccine. Producing a vaccine targeting the abundant serotype in China is essential to reducing the economic impact of IB on the poultry industry. Copyright © 2015 Elsevier B.V. All rights reserved.

Hepatitis B Virus Infection in Indonesia 15 Years After Adoption of a Universal Infant Vaccination Program: Possible Impacts of Low Birth Dose Coverage and a Vaccine-Escape Mutant.

PubMed

Purwono, Priyo Budi; Juniastuti; Amin, Mochamad; Bramanthi, Rendra; Nursidah; Resi, Erika Maria; Wahyuni, Rury Mega; Yano, Yoshihiko; Soetjipto; Hotta, Hak; Hayashi, Yoshitake; Utsumi, Takako; Lusida, Maria Inge

2016-09-07

A universal hepatitis B vaccination program for infants was adopted in Indonesia in 1997. Before its implementation, the prevalence of hepatitis B surface antigen (HBsAg)-positive individuals in the general population was approximately 5-10%. The study aimed to investigate the hepatitis B virus (HBV) serological status and molecular profile among children, 15 years after adoption of a universal infant vaccination program in Indonesia. According to the Local Health Office data in five areas, the percentages of children receiving three doses of hepatitis B vaccine are high (73.9-94.1%), whereas the birth dose coverage is less than 50%. Among 967 children in those areas, the seropositive rate of HBsAg in preschool- and school-aged children ranged from 2.1% to 4.2% and 0% to 5.9%, respectively. Of the 61 HBV DNA-positive samples, the predominant genotype/subtype was B/adw2 Subtype adw3 was identified in genotype C for the first time in this population. Six samples (11.5%) had an amino acid substitution within the a determinant of the S gene region, and one sample had T140I that was suggested as a vaccine-escape mutant type. The low birth dose coverage and the presence of a vaccine-escape mutant might contribute to the endemicity of HBV infection among children in Indonesia. © The American Society of Tropical Medicine and Hygiene.

Hepatitis B Virus Infection in Indonesia 15 Years after Adoption of a Universal Infant Vaccination Program: Possible Impacts of Low Birth Dose Coverage and a Vaccine-Escape Mutant

PubMed Central

Purwono, Priyo Budi; Juniastuti; Amin, Mochamad; Bramanthi, Rendra; Nursidah; Resi, Erika Maria; Wahyuni, Rury Mega; Yano, Yoshihiko; Soetjipto; Hotta, Hak; Hayashi, Yoshitake; Utsumi, Takako; Lusida, Maria Inge

2016-01-01

A universal hepatitis B vaccination program for infants was adopted in Indonesia in 1997. Before its implementation, the prevalence of hepatitis B surface antigen (HBsAg)–positive individuals in the general population was approximately 5–10%. The study aimed to investigate the hepatitis B virus (HBV) serological status and molecular profile among children, 15 years after adoption of a universal infant vaccination program in Indonesia. According to the Local Health Office data in five areas, the percentages of children receiving three doses of hepatitis B vaccine are high (73.9–94.1%), whereas the birth dose coverage is less than 50%. Among 967 children in those areas, the seropositive rate of HBsAg in preschool- and school-aged children ranged from 2.1% to 4.2% and 0% to 5.9%, respectively. Of the 61 HBV DNA–positive samples, the predominant genotype/subtype was B/adw2. Subtype adw3 was identified in genotype C for the first time in this population. Six samples (11.5%) had an amino acid substitution within the a determinant of the S gene region, and one sample had T140I that was suggested as a vaccine-escape mutant type. The low birth dose coverage and the presence of a vaccine-escape mutant might contribute to the endemicity of HBV infection among children in Indonesia. PMID:27402524

Immune responses of bison and efficacy after booster vaccination with Brucella abortus strain RB51

USDA-ARS?s Scientific Manuscript database

Thirty-one bison heifers were randomly assigned to saline (control; n=7) or single vaccination (n=24) with 1010 CFU of B. abortus strain RB51 (RB51). Some vaccinated bison were randomly selected for booster vaccination with 10**10 CFU of RB51 at 11 months after initial vaccination (n=16). When comp...

Progress towards Rapid Detection of Measles Vaccine Strains: a Tool To Inform Public Health Interventions

PubMed Central

2016-01-01

ABSTRACT Rapid differentiation of vaccine from wild-type strains in suspect measles cases is a valuable epidemiological tool that informs the public health response to this highly infectious disease. Few public health laboratories sequence measles virus-positive specimens to determine genotype, and the vaccine-specific real-time reverse transcriptase PCR (rRT-PCR) assay described by F. Roy et al. (J. Clin. Microbiol. 55:735–743, 2017, https://doi.org/10.1128/JCM.01879-16) offers a rapid, easily adoptable method to identify measles vaccine strains in suspect cases. PMID:28003421

Progress towards Rapid Detection of Measles Vaccine Strains: a Tool To Inform Public Health Interventions.

PubMed

Hacker, Jill K

2017-03-01

Rapid differentiation of vaccine from wild-type strains in suspect measles cases is a valuable epidemiological tool that informs the public health response to this highly infectious disease. Few public health laboratories sequence measles virus-positive specimens to determine genotype, and the vaccine-specific real-time reverse transcriptase PCR (rRT-PCR) assay described by F. Roy et al. (J. Clin. Microbiol. 55:735-743, 2017, https://doi.org/10.1128/JCM.01879-16) offers a rapid, easily adoptable method to identify measles vaccine strains in suspect cases. Copyright © 2017 American Society for Microbiology.

A comparative study of live attenuated F strain-derived Mycoplasma gallisepticum vaccines

USDA-ARS?s Scientific Manuscript database

Commercially available attenuated strains of Mycoplasma gallisepticum (MG) are commonly used within the layer industry to control MG-induced mycoplasmosis. Among these are two live MG vaccines derived from the moderately pathogenic MG “chick F” strain. In the present study, the commercially availa...

LEE-encoded regulator (Ler) mutants elicit serotype-specific protection, but not cross protection, against attaching and effacing E. coli strains.

PubMed

Zhu, C; Feng, S; Yang, Z; Davis, K; Rios, H; Kaper, J B; Boedeker, E C

2007-02-26

We previously showed that single dose orogastric immunization with an attenuated regulatory Lee-encoded regulator (ler) mutant of the rabbit enteropathogenic Escherichia coli (REPEC) strain E22 (O103:H2) protected rabbits from fatal infection with the highly virulent parent strain. In the current study we assessed the degree of homologous (serotype-specific) and heterologous (cross-serotype) protection induced by immunization with REPEC ler mutant strains of differing serotypes, or with a prototype strain RDEC-1 (O15:H-) which expresses a full array of ler up-regulated proteins. We constructed an additional ler mutant using RDEC-1 thus, permitting immunization with a ler mutant of either serotype, O15 or O103, followed by challenge with a virulent REPEC strain of the same or different serotypes. Consistent with our previous data, the current study demonstrated that rabbits immunized with a RDEC-1 ler mutant were protected from challenge with virulent RDEC-H19A (RDEC-1 transduced with Shiga toxin-producing phage H19A) of the same serotype. Rabbits immunized with RDEC-1 or E22 derivative ler mutants demonstrated significant increase in serum antibody titers to the respective whole bacterial cells expressing O antigen but not to the LEE-encoded proteins. However, immunization with the ler mutants of either E22 or RDEC-1 failed to protect rabbits from infections with virulent organisms belonging to different serotypes. In contrast, rabbits immunized with the prototype RDEC-1 were cross protected against challenge with the heterologous E22 strain as shown by normal weight gain, and the absence of clinical signs of disease or characteristic attaching and effacing (A/E) lesions. Immunization with RDEC-1 induced significantly elevated serum IgG titers to LEE-encoded proteins. We thus, demonstrated homologous protection induced by the REPEC ler mutants and heterologous protection by RDEC-1. The observed correlation between elevated immune responses to the LEE

[Attenuated rabies virus, ERA strain, in cattle and dogs vaccinated with multiple doses].

PubMed

Titoli, F; Pestalozza, S; Irsara, A; Palliola, E; Frescura, T; Civardi, A

1982-01-01

Investigation on the vaccination of 18 cattle and 5 dogs against rabies is reported. Each animal received multiple doses of ERA strain vaccine intramuscularly in the gluteal or masseter region. The saliva, the brain and salivary glands of the vaccinated animals were examined to detect the presence of ERA virus using immunofluorescent test and mouse inoculation. The virus was never found in the saliva and organs of treated animals. Circulating antibodies against ERA rabies virus were detected in all vaccinated cattle and dogs.

Spontaneous Gac Mutants of Pseudomonas Biological Control Strains: Cheaters or Mutualists? ▿

PubMed Central

Driscoll, William W.; Pepper, John W.; Pierson, Leland S.; Pierson, Elizabeth A.

2011-01-01

Bacteria rely on a range of extracellular metabolites to suppress competitors, gain access to resources, and exploit plant or animal hosts. The GacS/GacA two-component regulatory system positively controls the expression of many of these beneficial external products in pseudomonad bacteria. Natural populations often contain variants with defective Gac systems that do not produce most external products. These mutants benefit from a decreased metabolic load but do not appear to displace the wild type in nature. How could natural selection maintain the wild type in the presence of a mutant with enhanced growth? One hypothesis is that Gac mutants are “cheaters” that do not contribute to the public good, favored within groups but selected against between groups, as groups containing more mutants lose access to ecologically important external products. An alternative hypothesis is that Gac mutants have a mutualistic interaction with the wild type, so that each variant benefits by the presence of the other. In the biocontrol bacterium Pseudomonas chlororaphis strain 30-84, Gac mutants do not produce phenazines, which suppress competitor growth and are critical for biofilm formation. Here, we test the predictions of these alternative hypotheses by quantifying interactions between the wild type and the phenazine- and biofilm-deficient Gac mutant within growing biofilms. We find evidence that the wild type and Gac mutants interact mutualistically in the biofilm context, whereas a phenazine-defective structural mutant does not. Our results suggest that the persistence of alternative Gac phenotypes may be due to the stabilizing role of local mutualistic interactions. PMID:21873476

Structure-based design of NS2 mutants for attenuated influenza A virus vaccines.

PubMed

Akarsu, Hatice; Iwatsuki-Horimoto, Kiyoko; Noda, Takeshi; Kawakami, Eiryo; Katsura, Hiroaki; Baudin, Florence; Horimoto, Taisuke; Kawaoka, Yoshihiro

2011-01-01

We previously characterised the matrix 1 (M1)-binding domain of the influenza A virus NS2/nuclear export protein (NEP), reporting a critical role for the tryptophan (W78) residue that is surrounded by a cluster of glutamate residues in the C-terminal region that interacts with the M1 protein (Akarsu et al., 2003). To gain further insight into the functional role of this interaction, here we used reverse genetics to generate a series of A/WSN/33 (H1N1)-based NS2/NEP mutants for W78 or the C-terminal glutamate residues and assessed their effect on virus growth. We found that simultaneous mutations at three positions (E67S/E74S/E75S) of NS2/NEP were important for inhibition of influenza viral polymerase activity, although the W78S mutant and other glutamate mutants with single substitutions were not. In addition, double and triple substitutions in the NS2/NEP glutamine residues, which resulted in the addition of seven amino acids to the C-terminus of NS1 due to gene overlapping, resulted in virus attenuation in mice. Animal studies with this mutant suggest a potential benefit to incorporating these NS mutations into live vaccines. Copyright © 2010 Elsevier B.V. All rights reserved.

Induction of Strain-Transcending Immunity against Plasmodium chabaudi adami Malaria with a Multiepitope DNA Vaccine

PubMed Central

Scorza, T.; Grubb, K.; Smooker, P.; Rainczuk, A.; Proll, D.; Spithill, T. W.

2005-01-01

A major goal of current malaria vaccine programs is to develop multivalent vaccines that will protect humans against the many heterologous malaria strains that circulate in endemic areas. We describe a multiepitope DNA vaccine, derived from a genomic Plasmodium chabaudi adami DS DNA expression library of 30,000 plasmids, which induces strain-transcending immunity in mice against challenge with P. c. adami DK. Segregation of this library and DNA sequence analysis identified vaccine subpools encoding open reading frames (ORFs)/peptides of >9 amino acids [aa] (the V9+ pool, 303 plasmids) and >50 aa (V50+ pool, 56 plasmids), respectively. The V9+ and V50+ plasmid vaccine subpools significantly cross-protected mice against heterologous P. c. adami DK challenge, and protection correlated with the induction of both specific gamma interferon production by splenic cells and opsonizing antibodies. Bioinformatic analysis showed that 22 of the V50+ ORFs were polypeptides conserved among three or more Plasmodium spp., 13 of which are predicted hypothetical proteins. Twenty-nine of these ORFs are orthologues of predicted Plasmodium falciparum sequences known to be expressed in the blood stage, suggesting that this vaccine pool encodes multiple blood-stage antigens. The results have implications for malaria vaccine design by providing proof-of-principle that significant strain-transcending immunity can be induced using multiepitope blood-stage DNA vaccines and suggest that both cellular responses and opsonizing antibodies are necessary for optimal protection against P. c. adami. PMID:15845504

Antibodies induced by vaccination with purified chick embryo cell culture vaccine (PCECV) cross-neutralize non-classical bat lyssavirus strains.

PubMed

Malerczyk, Claudius; Selhorst, Thomas; Tordo, Noël; Moore, Susan; Müller, Thomas

2009-08-27

Tissue-culture vaccines like purified chick embryo cell vaccine (PCECV) have been shown to provide protection against classical rabies virus (RABV) via pre-exposure or post-exposure prophylaxis. A cross-neutralization study was conducted using a panel of 100 human sera, to determine, to what extent after vaccination with PCECV protection exists against non-classical bat lyssavirus strains like European bat lyssavirus (EBLV) type 1 and 2 and Australian bat lyssavirus (ABLV). Virus neutralizing antibody (VNA) concentrations against the rabies virus variants CVS-11, ABLV, EBLV-1 and EBLV-2 were determined by using a modified rapid fluorescent focus inhibition test. For ABLV and EBLV-2, the comparison to CVS-11 revealed almost identical results (100% adequate VNA concentrations >or=0.5 IU/mL; correlation coefficient r(2)=0.69 and 0.77, respectively), while for EBLV-1 more scattering was observed (97% adequate VNA concentrations; r(2)=0.50). In conclusion, vaccination with PCECV produces adequate VNA concentrations against classical RABV as well as non-classical lyssavirus strains ABLV, EBLV-1, and EBLV-2.

Evaluation of vaccine candidate potential of deltaaroA, deltahtrA and deltaaroAdeltahtrA mutants of Salmonella enterica subspecies enterica serovar Abortusequi in guinea pigs.

PubMed

Singh, Bhoj Raj; Chandra, Mudit; Hansda, Dhananjoy; Alam, Javed; Babu, Narayanan; Siddiqui, Mehtab Z; Agrawal, Ravi K; Sharma, Gautam

2013-04-01

Salmonella enterica subspecies enterica serovar Abortusequi (S. Abortusequi), a host adapted Salmonella causes abortions, still births and foal mortality in equids. Though known since more than 100 years, it is still a problem in many of the developing countries including India. There is dearth of really good vaccine affording immunity lasting at least for one full gestation. In search of a potential vaccine candidate, three defined deletion mutants (deltaaroA, deltahtrA and deltaaroAdeltahtrA) of S. Abortusequi were tested in guinea pig model for attenuation, safety, immunogenicity, humoral immune response, protective efficacy and persistence in host. The deltahtrA and deltaaroAdeltahtrA mutants were found to be safe on oral inoculation in doses as high as 4.2 x 10(9) cfu/animal. Also through subcutaneous inoculation deltaaroAdeltahtrA mutant did not induce any abortion in pregnant guinea pigs. All the three mutants did not induce any illness or death in 1-2 week-old baby guinea pigs except deltahtrA mutant which caused mortality on intraperitoneal inoculation. Inoculation with mutants protected against challenge and increased breeding efficiency of guinea pigs. After >4.5 months of mutant inoculation, guinea pigs were protected against abortifacient dose of wild type S. Abortusequi and mother guinea pigs also conferred resistance to their babies to the similar challenge. Early humoral immune response of S. Abortusequi mutants was characteristic. Faecal excretion of deltaaroA and htrA mutants was detected up to 45 days of inoculation in guinea pigs while deltaaroAdeltahtrA mutant could not be detected after 21 days of inoculation. The results indicated that the double deletion mutant (deltaaroAdeltahtrA) was the most effective and safe candidate for vaccination against S. Abortusequi through mucosal route of inoculation.

Formulation and Stabilization of Francisella tularensis Live Vaccine Strain

PubMed Central

OHTAKE, SATOSHI; MARTIN, RUSSELL A.; SAXENA, ATUL; LECHUGA-BALLESTEROS, DAVID; SANTIAGO, ARACELI E; BARRY, EILEEN M.; TRUONG-LE, VU

2012-01-01

Francisella tularensis live vaccine strain (F. tularensis LVS), a promising vaccine candidate for protection against F. tularensis exposure, is a particularly thermolabile vaccine and difficult to stabilize sufficiently for storage under refrigerated conditions. Our preliminary data show that F. tularensis LVS can be stabilized in the dried state using foam drying, a modified freeze drying method, with sugar-based formulations. The process was conducted under mild drying conditions, which resulted in a good titer retention following processing. The inclusion of osmolytes in the growth media resulted in an acceleration of growth kinetics, although no change in osmotolerance was observed. The optimized F. tularensis formulation, which contained trehalose, gelatin, and Pluronic F68 demonstrated stability for approximately 1.5 weeks at 37°C (i.e., time required for the vaccine to decrease in potency by 1 log10 colony forming unit) and for 12 weeks at 25°C. At refrigerator storage condition (4°C), stabilized F. tularensis LVS vaccine exhibited no activity loss for at least 12 weeks. This stabilization method utilizes conventional freeze dryers and pharmaceutically approved stabilizers, and thus can be readily implemented at many manufacturing sites for large-scale production of stabilized vaccines. The improved heat stability of the F. tularensis LVS could mitigate risks of vaccine potency loss during long-term storage, shipping, and distribution. PMID:21491457

A effective DNA vaccine against diverse genotype J infectious hematopoietic necrosis virus strains prevalent in China

USGS Publications Warehouse

Xu, Liming; Zhao, Jingzhuang; Liu, Miao; Kurath, Gael; Ren, Guangming; LaPatra, Scott E.; Yin, Jiasheng; Liu, Hongbai; Feng, Jian; Lu, Tongyan

2017-01-01

Infectious hematopoietic necrosis virus (IHNV) is the most important pathogen threatening the aquaculture of salmonid fish in China. In this study, a DNA vaccine, designated pIHNch-G, was constructed with the glycoprotein (G) gene of a Chinese IHNV isolate SD-12 (also called Sn1203) of genotype J. The minimal dose of vaccine required, the expression of the Mx-1 gene in the muscle (vaccine delivery site) and anterior kidney, and the titers of the neutralizing antibodies produced were used to evaluate the vaccine efficacy. To assess the potential utility of the vaccine in controlling IHNV throughout China, the cross protective efficacy of the vaccine was determined by challenging fish with a broad range of IHNV strains from different geographic locations in China. A single 100 ng dose of the vaccine conferred almost full protection to rainbow trout fry (3 g) against waterborne or intraperitoneal injection challenge with IHNV strain SD-12 as early as 4 days post-vaccination (d.p.v.), and significant protection was still observed at 180 d.p.v. Intragenogroup challenges showed that the DNA vaccine provided similar protection to the fish against all the Chinese IHNV isolates tested, suggesting that the vaccine can be widely used in China. Mx-1 gene expression was significantly upregulated in the muscle tissue (vaccine delivery site) and anterior kidney in the vaccinated rainbow trout at both 4 and 7 d.p.v. Similar levels of neutralizing antibodies were determined with each of the Chinese IHNV strains at 60 and 180 d.p.v. This DNA vaccine should play an important role in the control of IHN in China.

Risk analysis of inter-species reassortment through a Rift Valley fever phlebovirus MP-12 vaccine strain.

PubMed

Ly, Hoai J; Lokugamage, Nandadeva; Nishiyama, Shoko; Ikegami, Tetsuro

2017-01-01

Rift Valley fever (RVF) is a mosquito-borne zoonotic disease endemic to Africa and the Arabian Peninsula. The causative agent, Rift Valley fever phlebovirus (RVFV), belongs to the genus Phlebovirus in the family Phenuiviridae and causes high rates of abortions in ruminants, and hemorrhagic fever, encephalitis, or blindness in humans. Viral maintenance by mosquito vectors has led to sporadic RVF outbreaks in ruminants and humans in endemic countries, and effective vaccination of animals and humans may minimize the impact of this disease. A live-attenuated MP-12 vaccine strain is one of the best characterized RVFV strains, and was conditionally approved as a veterinary vaccine in the U.S. Live-attenuated RVF vaccines including MP-12 strain may form reassortant strains with other bunyavirus species. This study thus aimed to characterize the occurrence of genetic reassortment between the MP-12 strain and bunyavirus species closely related to RVFV. The Arumowot virus (AMTV) and Gouleako goukovirus (GOLV), are transmitted by mosquitoes in Africa. The results of this study showed that GOLV does not form detectable reassortant strains with the MP-12 strain in co-infected C6/36 cells. The AMTV also did not form any reassortant strains with MP-12 strain in co-infected C6/36 cells, due to the incompatibility among N, L, and Gn/Gc proteins. A lack of reassortant formation could be due to a functional incompatibility of N and L proteins derived from heterologous species, and due to a lack of packaging via heterologous Gn/Gc proteins. The MP-12 strain did, however, randomly exchange L-, M-, and S-segments with a genetic variant strain, rMP12-GM50, in culture cells. The MP-12 strain is thus unlikely to form any reassortant strains with AMTV or GOLV in nature.

Safety studies with the oral rabies virus vaccine strain SPBN GASGAS in the small Indian mongoose (Herpestes auropunctatus).

PubMed

Ortmann, Steffen; Vos, Ad; Kretzschmar, Antje; Walther, Nomusa; Kaiser, Christiane; Freuling, Conrad; Lojkic, Ivana; Müller, Thomas

2018-03-13

Oral vaccination of the small Indian mongoose against rabies has been suggested as a potential tool to eliminate mongoose-mediated rabies on several Caribbean islands. A recently developed oral rabies virus vaccine strain, SPBN GASGAS, has already been shown to be efficacious in this reservoir species. Since, all available oral rabies vaccines are based on replication-competent viruses and vaccine baits are distributed unsupervised in the environment, enhanced safety standards for such vaccine types are required. The results of safety studies, including overdose, repeated doses, dissemination and different routes of administration, in the target species are presented. It was shown that the construct was apathogenic, irrespective of dose and route of administration. Even when it was inoculated directly in the brain, it did not induce rabies infection. Furthermore, the vaccine strain did not spread within the target species after direct oral instillation beyond the site of entry. The vaccine strain SPBN GASGAS meets the safety requirements for live rabies virus vaccines in this target species, the small Indian mongoose.

A chronicle of serologic response in commercial layer chickens to vaccination with commercial F strain Mycoplasma gallisepticum vaccine.

PubMed

Branton, S L; Leigh, S A; Purswell, J L; Evans, J D; Collier, S D; Olanrewaju, H A; Pharr, G T

2010-09-01

Vaccination of multi-age layer operations, wherein one million plus commercial layer chickens are housed, has been spurious until the development of a self-propelled, constant-speed spray vaccinator. Still, even with its use, live Mycoplasma gallisepticum (MG) vaccinations have been questionable in terms of seroconversion. Using the vaccinator as a research tool over the past 5 yr, factors have been elucidated which impact seroconversion to one live MG vaccine in particular, the F strain of MG (FMG). These factors include the type of nozzle used to spray the vaccine, the temperature of the water used to rehydrate and administer the vaccine, and the pH and osmolarity of the fluid used to apply the vaccine. In the present study, one farm was monitored for its seroconversion rates over 4 1/2 yr, during which time the FMG vaccination protocol was amended as factors were identified that enhanced seroconversion rates. The results of this study showed that implementation and inclusion of the optimized factors into the vaccination protocol for FMG enhanced seroconversion rates because they went from an initial 50%-55% positive seroconversion rate to a consistent 100% positive seroconversion rate over the 56-mo study period.

Mucosal and Parenteral Vaccination against Acute and Latent Murine Cytomegalovirus (MCMV) Infection by Using an Attenuated MCMV Mutant

PubMed Central

MacDonald, Margaret R.; Li, Xi-Yang; Stenberg, Richard M.; Campbell, Ann E.; Virgin, Herbert W.

1998-01-01

We used a live attenuated murine cytomegalovirus (MCMV) mutant to analyze mechanisms of vaccination against acute and latent CMV infection. We selected MCMV mutant RV7 as a vaccine candidate since this virus grows well in tissue culture but is profoundly attenuated for growth in normal and severe combined immunodeficient (SCID) mice (V. J. Cavanaugh et al., J. Virol. 70:1365–1374, 1996). BALB/c mice were immunized twice (0 and 14 days) subcutaneously (s.c.) with tissue culture-passaged RV7 and then challenged with salivary gland-passaged wild-type MCMV (sgMCMV) intraperitoneally (i.p.) on day 28. RV7 vaccination protected mice against challenge with 105 PFU of sgMCMV, a dose that killed 100% of mock-vaccinated mice. RV7 vaccination reduced MCMV replication 100- to 500-fold in the spleen between 1 and 8 days after challenge. We used the capacity to control replication of MCMV in the spleen 4 days after challenge as a surrogate for protection. Protection was antigen specific and required both live RV7 and antigen-specific lymphocytes. Interestingly, RV7 was effective when administered s.c., i.p., perorally, intranasally, and intragastrically, demonstrating that attenuated CMV applied to mucosal surfaces can elicit protection against parenteral virus challenge. B cells and immunoglobulin G were not essential for RV7-induced immunity since B-cell-deficient mice were effectively vaccinated by RV7. CD8 T cells, but not CD4 T cells, were critical for RV7-induced protection. Depletion of CD8 T cells by passive transfer of monoclonal anti-CD8 (but not anti-CD4) antibody abrogated RV7-mediated protection, and RV7 vaccination was less efficient in CD8 T-cell-deficient mice with a targeted mutation in the β2-microglobulin gene. Although gamma interferon is important for innate resistance to MCMV, it was not essential for RV7 vaccination since gamma interferon receptor-deficient mice were protected by RV7 vaccination. Establishment of and/or reactivation from latency by sg

The Live Attenuated Actinobacillus pleuropneumoniae Triple-Deletion Mutant ΔapxIC ΔapxIIC ΔapxIV-ORF1 Strain, SLW05, Immunizes Pigs against Lethal Challenge with Haemophilus parasuis

PubMed Central

Fu, Shulin; Ou, Jiwen; Zhang, Minmin; Xu, Juan; Liu, Huazhen; Liu, Jinlin; Yuan, Fangyan; Chen, Huanchun

2013-01-01

Haemophilus parasuis and Actinobacillus pleuropneumoniae both belong to the family Pasteurellaceae and are major respiratory pathogens that cause large economic losses in the pig industry worldwide. We previously constructed an attenuated A. pleuropneumoniae serovar 1 live vaccine prototype, SLW05 (ΔapxIC ΔapxIIC ΔapxIV-ORF1), which is able to produce nontoxic but immunogenic ApxIA, ApxIIA, and ApxIVA. This triple-deletion mutant strain was shown to elicit protective immunity against virulent A. pleuropneumoniae. In the present study, we investigated whether immunization with SLW05 could also protect against lethal challenge with virulent H. parasuis SH0165 (serovar 5) or MD0322 (serovar 4). The SLW05 strain was found to elicit a strong humoral antibody response in pigs and to confer significant protection against challenge with a lethal dose of H. parasuis SH0165 or MD0322. IgG subtype analysis revealed that SLW05 induces a bias toward a Th1-type immune response and stimulates interleukin 2 (IL-2) and gamma interferon (IFN-γ) production. Moreover, antisera from SLW05-vaccinated pigs efficiently inhibited both A. pleuropneumoniae and H. parasuis growth in a whole-blood assay. This is the first report that a live attenuated A. pleuropneumoniae vaccine with SLW05 can protect against lethal H. parasuis infection, which provides a novel approach for developing an attenuated H. parasuis vaccine. PMID:23220998

High-Resolution Melting-Curve Analysis of obg Gene to Differentiate the Temperature-Sensitive Mycoplasma synoviae Vaccine Strain MS-H from Non-Temperature-Sensitive Strains

PubMed Central

Shahid, Muhammad A.; Markham, Philip F.; Marenda, Marc S.; Agnew-Crumpton, Rebecca; Noormohammadi, Amir H.

2014-01-01

Temperature-sensitive (ts +) vaccine strain MS-H is the only live attenuated M. synoviae vaccine commercially available for use in poultry. With increasing use of this vaccine to control M. synoviae infections, differentiation of MS-H from field M. synoviae strains and from rarely occurring non-temperature-sensitive (ts –) MS-H revertants has become important, especially in countries where local strains are indistinguishable from MS-H by sequence analysis of variable lipoprotein haemagglutinin (vlhA) gene. Single nucleotide polymorphisms (SNPs) in the obg of MS-H have been found to associate with ts phenotype. In this study, four PCRs followed by high-resolution melting (HRM)-curve analysis of the regions encompassing these SNPs were developed and evaluated for their potential to differentiate MS-H from 36 M. synoviae strains/isolates. The nested-obg PCR-HRM differentiated ts + MS-H vaccine not only from field M. synoviae strains/isolates but also from ts – MS-H revertants. The mean genotype confidence percentages, 96.9±3.4 and 8.8±11.2 for ts + and ts – strains, respectively, demonstrated high differentiating power of the nested-obg PCR-HRM. Using a combination of nested-obg and obg-F3R3 PCR-HRM, 97% of the isolates/strains were typed according to their ts phenotype with all MS-H isolates typed as MS-H. A set of respiratory swabs from MS-H vaccinated specific pathogen free chickens and M. synoviae infected commercial chicken flocks were tested using obg PCR-HRM system and results were consistent with those of vlhA genotyping. The PCR-HRM system developed in this study, proved to be a rapid and reliable tool using pure M. synoviae cultures as well as direct clinical specimens. PMID:24643035

Characterization of two recent Japanese field isolates of canine distemper virus and examination of the avirulent strain utility as an attenuated vaccine.

PubMed

Takenaka, Akiko; Yoneda, Misako; Seki, Takahiro; Uema, Masashi; Kooriyama, Takanori; Nishi, Toshiya; Fujita, Kentaro; Miura, Ryuichi; Tsukiyama-Kohara, Kyoko; Sato, Hiroki; Kai, Chieko

2014-12-05

Recently, several new strains of canine distemper virus (CDV) have been isolated in Japan. To investigate their pathogenesis in dogs, the Yanaka and Bunkyo-K strains were investigated by infecting dogs and determining clinical signs, amount of virus, and antibody responses. The Yanaka strain is avirulent and induced an antibody response. The Bunkyo-K strain induced typical CDV clinical signs in infected dogs and virulence was enhanced by brain passage. Molecular and phylogenetic analyses of H genes demonstrated the Bunkyo-K strains were of a different lineage from Asia-1 group including the Yanaka strain and Asia-2 group that contain recent Japanese isolates, which were recently identified as major prevalent strains worldwide but distinct from old vaccine strains. Based on these data, we tested the ability of the Yanaka strain for vaccination. Inoculation with the Yanaka strain efficiently induced CDV neutralizing antibodies with no clinical signs, and the protection effects against challenge with either old virulent strain or Bunkyo-K strain were equal or greater when compared with vaccination by an original vaccine strain. Thus, the Yanaka strain is a potential vaccine candidate against recent prevalent CDV strains. Copyright © 2014 Elsevier B.V. All rights reserved.

Induction and characterization of morphologic mutants in a natural Saccharomyces cerevisiae strain.

PubMed

Barberio, Claudia; Bianchi, Lucia; Pinzauti, Francesca; Lodi, Tiziana; Ferrero, Iliana; Polsinelli, Mario; Casalone, Enrico

2007-02-01

Saccharomyces cerevisiae is a good model with which to study the effects of morphologic differentiation on the ecological behaviour of fungi. In this work, 33 morphologic mutants of a natural strain of S. cerevisiae, obtained with UV mutagenesis, were selected for their streak shape and cell shape on rich medium. Two of them, showing both high sporulation proficiency and constitutive pseudohyphal growth, were analysed from a genetic and physiologic point of view. Each mutant carries a recessive monogenic mutation, and the two mutations reside in unlinked genes. Flocculation ability and responsiveness to different stimuli distinguished the two mutants. Growth at 37 degrees C affected the cell but not the colony morphology, suggesting that these two phenotypes are regulated differently. The effect of ethidium bromide, which affects mitochondrial DNA replication, suggested a possible "retrograde action" of mitochondria in pseudohyphal growth.

Intramuscular Immunization of Mice with a Live-Attenuated Triple Mutant of Yersinia pestis CO92 Induces Robust Humoral and Cell-Mediated Immunity To Completely Protect Animals against Pneumonic Plague.

PubMed

Tiner, Bethany L; Sha, Jian; Ponnusamy, Duraisamy; Baze, Wallace B; Fitts, Eric C; Popov, Vsevolod L; van Lier, Christina J; Erova, Tatiana E; Chopra, Ashok K

2015-12-01

Earlier, we showed that the Δlpp ΔmsbB Δail triple mutant of Yersinia pestis CO92 with deleted genes encoding Braun lipoprotein (Lpp), an acyltransferase (MsbB), and the attachment invasion locus (Ail), respectively, was avirulent in a mouse model of pneumonic plague. In this study, we further evaluated the immunogenic potential of the Δlpp ΔmsbB Δail triple mutant and its derivative by different routes of vaccination. Mice were immunized via the subcutaneous (s.c.) or the intramuscular (i.m.) route with two doses (2 × 10(6) CFU/dose) of the above-mentioned triple mutant with 100% survivability of the animals. Upon subsequent pneumonic challenge with 70 to 92 50% lethal doses (LD(50)) of wild-type (WT) strain CO92, all of the mice survived when immunization occurred by the i.m. route. Since Ail has virulence and immunogenic potential, a mutated version of Ail devoid of its virulence properties was created, and the genetically modified ail replaced the native ail gene on the chromosome of the Δlpp ΔmsbB double mutant, creating a Δlpp ΔmsbB::ailL2 vaccine strain. This newly generated mutant was attenuated similarly to the Δlpp ΔmsbB Δail triple mutant when administered by the i.m. route and provided 100% protection to animals against subsequent pneumonic challenge. Not only were the two above-mentioned mutants cleared rapidly from the initial i.m. site of injection in animals with no histopathological lesions, the immunized mice did not exhibit any disease symptoms during immunization or after subsequent exposure to WT CO92. These two mutants triggered balanced Th1- and Th2-based antibody responses and cell-mediated immunity. A substantial increase in interleukin-17 (IL-17) from the T cells of vaccinated mice, a cytokine of the Th17 cells, further augmented their vaccine potential. Thus, the Δlpp ΔmsbB Δail and Δlpp ΔmsbB::ailL2 mutants represent excellent vaccine candidates for plague, with the latter mutant still retaining Ail immunogenicity but

[Development of an inactivated vaccine for the protection of cattle against Aujeszky's disease].

PubMed

Straub, O C

1990-07-01

The effects of an inactivated strain of Aujeszky's disease vaccine in cattle were investigated. It has not been possible to use vaccines licensed for use in pigs successfully in cattle even though cattle develop neutralizing antibodies to these vaccines. The addition of zinc compounds to the vaccines resulted in protection in cattle. The basis for the use of zinc is discussed. A mutant based vaccine was effective following local administration, but was not when administered parenterally. Anti-prostaglandin was not effective either, despite its successful use in sheep when administered with BHV1. The vaccine presents a prospect for immunising dogs and cats, and the addition of zinc compounds to other drugs and inducers is discussed.

Poly(3-hydroxybutyrate) hyperproduction by a global nitrogen regulator NtrB mutant strain of Paracoccus denitrificans PD1222

PubMed Central

Olaya-Abril, Alfonso; Luque-Almagro, Víctor M; Manso, Isabel; Gates, Andrew J; Moreno-Vivián, Conrado; Richardson, David J

2017-01-01

Abstract Paracoccus denitrificans PD1222 accumulates short-length polyhydroxyalkanoates, poly(3-hydroxybutyrate), under nitrogen-deficient conditions. Polyhydroxybutyrate metabolism requires the 3-ketoacyl-CoA thiolase PhaA, the acetoacetyl-CoA dehydrogenase/reductase PhaB and the synthase PhaC for polymerization. Additionally, P. denitrificans PD1222 grows aerobically with nitrate as sole nitrogen source. Nitrate assimilation is controlled negatively by ammonium through the two-component NtrBC system. NtrB is a sensor kinase that autophosphorylates a histidine residue under low-nitrogen concentrations and, in turn, transfers a phosphoryl group to an aspartate residue of the response regulator NtrC protein, which acts as a transcriptional activator of the P. denitrificans PD1222 nasABGHC genes. The P. denitrificans PD1222 NtrB mutant was unable to use nitrate efficiently as nitrogen source when compared to the wild-type strain, and it also overproduced poly(3-hydroxybutyrate). Acetyl-CoA concentration in the P. denitrificans PD1222 NtrB mutant strain was higher than in the wild-type strain. The expression of the phaC gene was also increased in the NtrB mutant when compared to the wild-type strain. These results suggest that accumulation of poly(3-hydroxybutyrate) in the NtrB mutant strain of PD1222 responds to the high levels of acetyl-CoA that accumulate in the cytoplasm as consequence of its inability to efficiently use nitrate as nitrogen source. PMID:29228177

Quantitative mutant analysis of viral quasispecies by chip-based matrix-assisted laser desorption/ ionization time-of-flight mass spectrometry

PubMed Central

Amexis, Georgios; Oeth, Paul; Abel, Kenneth; Ivshina, Anna; Pelloquin, Francois; Cantor, Charles R.; Braun, Andreas; Chumakov, Konstantin

2001-01-01

RNA viruses exist as quasispecies, heterogeneous and dynamic mixtures of mutants having one or more consensus sequences. An adequate description of the genomic structure of such viral populations must include the consensus sequence(s) plus a quantitative assessment of sequence heterogeneities. For example, in quality control of live attenuated viral vaccines, the presence of even small quantities of mutants or revertants may indicate incomplete or unstable attenuation that may influence vaccine safety. Previously, we demonstrated the monitoring of oral poliovirus vaccine with the use of mutant analysis by PCR and restriction enzyme cleavage (MAPREC). In this report, we investigate genetic variation in live attenuated mumps virus vaccine by using both MAPREC and a platform (DNA MassArray) based on matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. Mumps vaccines prepared from the Jeryl Lynn strain typically contain at least two distinct viral substrains, JL1 and JL2, which have been characterized by full length sequencing. We report the development of assays for characterizing sequence variants in these substrains and demonstrate their use in quantitative analysis of substrains and sequence variations in mixed virus cultures and mumps vaccines. The results obtained from both the MAPREC and MALDI-TOF methods showed excellent correlation. This suggests the potential utility of MALDI-TOF for routine quality control of live viral vaccines and for assessment of genetic stability and quantitative monitoring of genetic changes in other RNA viruses of clinical interest. PMID:11593021

Electrical phenotypes of calcium transport mutant strains of a filamentous fungus, Neurospora crassa.

PubMed

Hamam, Ahmed; Lew, Roger R

2012-05-01

We characterized the electrical phenotypes of mutants with mutations in genes encoding calcium transporters-a mechanosensitive channel homolog (MscS), a Ca(2+)/H(+) exchange protein (cax), and Ca(2+)-ATPases (nca-1, nca-2, nca-3)-as well as those of double mutants (the nca-2 cax, nca-2 nca-3, and nca-3 cax mutants). The electrical characterization used dual impalements to obtain cable-corrected current-voltage measurements. Only two types of mutants (the MscS mutant; the nca-2 mutant and nca-2-containing double mutants) exhibited lower resting potentials. For the nca-2 mutant, on the basis of unchanged conductance and cyanide-induced depolarization of the potential, the cause is attenuated H(+)-ATPase activity. The growth of the nca-2 mutant-containing strains was inhibited by elevated extracellular Ca(2+) levels, indicative of lesions in Ca(2+) homeostasis. However, the net Ca(2+) effluxes of the nca-2 mutant, measured noninvasively with a self-referencing Ca(2+)-selective microelectrode, were similar to those of the wild type. All of the mutants exhibited osmosensitivity similar to that of the wild type (the turgor of the nca-2 mutant was also similar to that of the wild type), suggesting that Ca(2+) signaling does not play a role in osmoregulation. The hyphal tip morphology and tip-localized mitochondria of the nca-2 mutant were similar to those of the wild type, even when the external [Ca(2+)] was elevated. Thus, although Ca(2+) homeostasis is perturbed in the nca-2 mutant (B. J. Bowman et al., Eukaryot. Cell 10:654-661, 2011), the phenotype does not extend to tip growth or to osmoregulation but is revealed by lower H(+)-ATPase activity.

Electrical Phenotypes of Calcium Transport Mutant Strains of a Filamentous Fungus, Neurospora crassa

PubMed Central

Hamam, Ahmed

2012-01-01

We characterized the electrical phenotypes of mutants with mutations in genes encoding calcium transporters—a mechanosensitive channel homolog (MscS), a Ca2+/H+ exchange protein (cax), and Ca2+-ATPases (nca-1, nca-2, nca-3)—as well as those of double mutants (the nca-2 cax, nca-2 nca-3, and nca-3 cax mutants). The electrical characterization used dual impalements to obtain cable-corrected current-voltage measurements. Only two types of mutants (the MscS mutant; the nca-2 mutant and nca-2-containing double mutants) exhibited lower resting potentials. For the nca-2 mutant, on the basis of unchanged conductance and cyanide-induced depolarization of the potential, the cause is attenuated H+-ATPase activity. The growth of the nca-2 mutant-containing strains was inhibited by elevated extracellular Ca2+ levels, indicative of lesions in Ca2+ homeostasis. However, the net Ca2+ effluxes of the nca-2 mutant, measured noninvasively with a self-referencing Ca2+-selective microelectrode, were similar to those of the wild type. All of the mutants exhibited osmosensitivity similar to that of the wild type (the turgor of the nca-2 mutant was also similar to that of the wild type), suggesting that Ca2+ signaling does not play a role in osmoregulation. The hyphal tip morphology and tip-localized mitochondria of the nca-2 mutant were similar to those of the wild type, even when the external [Ca2+] was elevated. Thus, although Ca2+ homeostasis is perturbed in the nca-2 mutant (B. J. Bowman et al., Eukaryot. Cell 10:654–661, 2011), the phenotype does not extend to tip growth or to osmoregulation but is revealed by lower H+-ATPase activity. PMID:22408225

Cross-protective efficacy of engineering serotype A foot-and-mouth disease virus vaccine against the two pandemic strains in swine.

PubMed

Zheng, Haixue; Lian, Kaiqi; Yang, Fan; Jin, Ye; Zhu, Zixiang; Guo, Jianhong; Cao, Weijun; Liu, Huanan; He, Jijun; Zhang, Keshan; Li, Dan; Liu, Xiangtao

2015-10-26

Foot-and-mouth disease (FMD) is a highly contagious vesicular disease that affects domestic and wild cloven-hoofed animals worldwide. Recently, a series of outbreaks of type A FMDV occurred in Southeast Asian countries, China, the Russia Federation, Mongolia, Kazakhstan and South Korea. The FMD virus (A/GDMM/CHA/2013) from China's Guangdong province (2013) is representative of those responsible for the latest epidemic, and has low amino acid identity (93.9%) in VP1 protein with the epidemic strain A/WH/CHA/09 from Wuhan, China in 2009. Both of isolates belong to the Sea-97 genotype of ASIA topotype. Therefore, the application of a new vaccine strain with cross-protective efficacy is of fundamental importance to control the spread of the two described pandemic strains. A chimeric strain rA/P1-FMDV constructed by our lab previously through replacing the P1 gene in the vaccine strain O/CHA/99 with that from the epidemic stain A/WH/CHA/09, has been demonstrated to exhibit good growth characteristics in culture, and the rA/P1-FMDV inactivated vaccine can provide protection against epidemic strain A/WH/CHA/09 in cattle. However, it is still unclear whether the vaccine produces efficient protection against the new pandemic strain (A/GDMM/CHA/2013). Here, vaccine matching and pig 50% protective dose (PD50) tests were performed to assess the vaccine potency. The vaccine matching test showed cross-reactivity of sera from full dose vaccine vaccinated pigs with A/WH/CHA/09 and A/GDMM/CHA/2013 isolates, with average r1 values of 0.94±0.12 and 0.68±0.06 (r1≥0.3), which indicates that the rA/P1-FMDV vaccine is likely to confer good cross-protection against the two isolates. When challenged with two pandemic isolates A/WH/CHA/09 and A/GDMM/CHA/2013 strain, the vaccine achieved 12.51 PD50 and 10.05 PD50 per dose (2.8μg), respectively. The results indicated that the rA/P1-FMDV inactivated vaccine could protect pigs against both A/WH/CHA/09 and A/GDMM/CHA/2013 pandemic isolates

A PfRH5-Based Vaccine Is Efficacious against Heterologous Strain Blood-Stage Plasmodium falciparum Infection in Aotus Monkeys

PubMed Central

Douglas, Alexander D.; Baldeviano, G. Christian; Lucas, Carmen M.; Lugo-Roman, Luis A.; Crosnier, Cécile; Bartholdson, S. Josefin; Diouf, Ababacar; Miura, Kazutoyo; Lambert, Lynn E.; Ventocilla, Julio A.; Leiva, Karina P.; Milne, Kathryn H.; Illingworth, Joseph J.; Spencer, Alexandra J.; Hjerrild, Kathryn A.; Alanine, Daniel G.W.; Turner, Alison V.; Moorhead, Jeromy T.; Edgel, Kimberly A.; Wu, Yimin; Long, Carole A.; Wright, Gavin J.; Lescano, Andrés G.; Draper, Simon J.

2015-01-01

Summary Antigenic diversity has posed a critical barrier to vaccine development against the pathogenic blood-stage infection of the human malaria parasite Plasmodium falciparum. To date, only strain-specific protection has been reported by trials of such vaccines in nonhuman primates. We recently showed that P. falciparum reticulocyte binding protein homolog 5 (PfRH5), a merozoite adhesin required for erythrocyte invasion, is highly susceptible to vaccine-inducible strain-transcending parasite-neutralizing antibody. In vivo efficacy of PfRH5-based vaccines has not previously been evaluated. Here, we demonstrate that PfRH5-based vaccines can protect Aotus monkeys against a virulent vaccine-heterologous P. falciparum challenge and show that such protection can be achieved by a human-compatible vaccine formulation. Protection was associated with anti-PfRH5 antibody concentration and in vitro parasite-neutralizing activity, supporting the use of this in vitro assay to predict the in vivo efficacy of future vaccine candidates. These data suggest that PfRH5-based vaccines have potential to achieve strain-transcending efficacy in humans. PMID:25590760

Protection against Experimental Cryptococcosis following Vaccination with Glucan Particles Containing Cryptococcus Alkaline Extracts

PubMed Central

Lee, Chrono K.; Huang, Haibin; Shen, Zu T.; Lodge, Jennifer K.; Leszyk, John; Ostroff, Gary R.

2015-01-01

ABSTRACT A vaccine capable of protecting at-risk persons against infections due to Cryptococcus neoformans and Cryptococcus gattii could reduce the substantial global burden of human cryptococcosis. Vaccine development has been hampered though, by lack of knowledge as to which antigens are immunoprotective and the need for an effective vaccine delivery system. We made alkaline extracts from mutant cryptococcal strains that lacked capsule or chitosan. The extracts were then packaged into glucan particles (GPs), which are purified Saccharomyces cerevisiae cell walls composed primarily of β-1,3-glucans. Subcutaneous vaccination with the GP-based vaccines provided significant protection against subsequent pulmonary infection with highly virulent strains of C. neoformans and C. gattii. The alkaline extract derived from the acapsular strain was analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS), and the most abundant proteins were identified. Separation of the alkaline extract by size exclusion chromatography revealed fractions that conferred protection when loaded in GP-based vaccines. Robust Th1- and Th17-biased CD4+ T cell recall responses were observed in the lungs of vaccinated and infected mice. Thus, our preclinical studies have indicated promising cryptococcal vaccine candidates in alkaline extracts delivered in GPs. Ongoing studies are directed at identifying the individual components of the extracts that confer protection and thus would be promising candidates for a human vaccine. PMID:26695631

Molecular approaches to fish vaccines

USGS Publications Warehouse

Winton, J.R.

1998-01-01

For more than 50 years, researchers have tested a variety of killed, attenuated, and subunit preparations for control offish diseases. The earliest fish vaccines used killed preparations containing whole bacteria, viruses, or parasites and today, several bacterins have become commercially successful with more expected as improved delivery systems and adjuvants are realized. Live, attenuated vaccines have been developed by serial passage of a pathogen in culture or by using naturally occurring mutants and cross-reacting strains. These generally offer excellent protection and are cost-effective, but concerns about residual virulence or their effects on other aquatic species make them difficult candidates for licensing. In recent years, the tools of molecular biology have been applied to construction of a variety of recombinant, engineered, or subunit vaccines for fish. Among the approaches to be discussed are: attenuated strains of viruses and bacteria created by deletion of specific genes associated with virulence, in vitro synthesis of protective antigens from genes cloned into E. coli or baculovirus expression systems, chemical synthesis of peptides that represent protective epitopes, and direct immunization with DNA coding for protective antigens. Preparations representing each of these approaches have been tested in laboratory or field trials with various results and such vaccines promise to be safe and relatively inexpensive if they are able to provide protection when delivered by immersion. A significant advantage of genetically engineered vaccines is the ability to construct multivalent preparations that can protect fish against several pathogens or different strains of the same pathogen. While many of these novel vaccine strategies have been effective at stimulating specific immunity in the laboratory, more work is needed to develop better delivery systems and to overcome potential regulatory concerns.

Circulation of a type 1 recombinant vaccine-derived poliovirus strain in a limited area in Romania.

PubMed

Combiescu, M; Guillot, S; Persu, A; Baicus, A; Pitigoi, D; Balanant, J; Oprisan, G; Crainic, R; Delpeyroux, F; Aubert-Combiescu, A

2007-01-01

After intensive immunisation campaigns with the oral polio vaccine (OPV) as part of the Global Polio Eradication Initiative, poliomyelitis due to wild viruses has disappeared from most parts of the world, including Europe. Here, we report the characterization of a serotype 1 vaccine-derived poliovirus (VDPV) isolated from one acute flaccid paralysis (AFP) case with tetraplegia and eight healthy contacts belonging to the same small socio-cultural group having a low vaccine coverage living in a small town in Romania. The genomes of the isolated strains appeared to be tripartite type 1/type 2/type 1 vaccine intertypic recombinant genomes derived from a common ancestor strain. The presence of 1.2% nucleotide substitutions in the VP1 capsid protein coding region of most of the strains indicated a circulation time of about 14 months. These VDPVs were thermoresistant and, in transgenic mice expressing the human poliovirus receptor, appeared to have lost the attenuated phenotype. These results suggest that small populations with low vaccine coverage living in globally well-vaccinated countries can be the origin of VDPV emergence and circulation. These results reaffirm the importance of active surveillance for acute flaccid paralysis and poliovirus in both polio-free and polio-endemic countries.

Development and Characterization of an Infectious cDNA Clone of the Modified Live Virus Vaccine Strain of Equine Arteritis Virus

PubMed Central

Zhang, Jianqiang; Go, Yun Young; Huang, Chengjin M.; Meade, Barry J.; Lu, Zhengchun; Snijder, Eric J.; Timoney, Peter J.

2012-01-01

A stable full-length cDNA clone of the modified live virus (MLV) vaccine strain of equine arteritis virus (EAV) was developed. RNA transcripts generated from this plasmid (pEAVrMLV) were infectious upon transfection into mammalian cells, and the resultant recombinant virus (rMLV) had 100% nucleotide identity to the parental MLV vaccine strain of EAV. A single silent nucleotide substitution was introduced into the nucleocapsid gene (pEAVrMLVB), enabling the cloned vaccine virus (rMLVB) to be distinguished from parental MLV vaccine as well as other field and laboratory strains of EAV by using an allelic discrimination real-time reverse transcription (RT)-PCR assay. In vitro studies revealed that the cloned vaccine virus rMLVB and the parental MLV vaccine virus had identical growth kinetics and plaque morphologies in equine endothelial cells. In vivo studies confirmed that the cloned vaccine virus was very safe and induced high titers of neutralizing antibodies against EAV in experimentally immunized horses. When challenged with the heterologous EAV KY84 strain, the rMLVB vaccine virus protected immunized horses in regard to reducing the magnitude and duration of viremia and virus shedding but did not suppress the development of signs of EVA, although these were reduced in clinical severity. The vaccine clone pEAVrMLVB could be further manipulated to improve the vaccine efficacy as well as to develop a marker vaccine for serological differentiation of EAV naturally infected from vaccinated animals. PMID:22739697

Characterization of a cold-adapted esterase and mutants from a psychotolerant Pseudomonas sp. strain.

PubMed

Dong, Juan; Gasmalla, Mohammed A A; Zhao, Wei; Sun, Jingtao; Liu, Wenyu; Wang, Mingming; Han, Liang; Yang, Ruijin

2017-09-01

A cold-adapted esterase-producing strain named T1-39 was isolated from Glacier No. 1, Tianshan, People's Republic of China and identified as Pseudomonas sp. from 16S rRNA sequence analysis. The esterase (EstT1-39) secreted by this strain preferentially hydrolyzed esters of glycerol with short- and medium-chain fatty acids. Mutants of T1-39 were generated by the atmospheric and room temperature plasma method and screened for enhanced esterase activity. Among all the mutants, strain TB11 had 4.45-fold higher esterase productivity than T1-39, with high genetic stability over 10 generations of continuous cultivation. Maximum activity of EstT1-39 and EstTB11 was observed at 30 ℃, pH 9.0 and 25 ℃, pH 8.5, respectively. EstTB11 was thermally more stable (50 ℃ for 1 H) and active over a broader pH range than EstT1-39. EstTB11 also retained 38% of its maximal activity at 0 ℃ and was found to be able to hydrolyze milk fats into short- and medium-chain fatty acids at 4 ℃. The characteristics of EstT1-39 made it a cold-adapted enzyme and the EstTB11 from the mutant, with its higher activity at lower temperatures, may be suitable for the production of aromas and flavors in the dairy industry. © 2016 International Union of Biochemistry and Molecular Biology, Inc.

Gluco-oligosaccharides synthesized by glucosyltransferases from constitutive mutants of Leuconostoc mesenteroides strain Lm 28.

PubMed

Iliev, I; Vassileva, T; Ignatova, C; Ivanova, I; Haertlé, T; Monsan, P; Chobert, J-M

2008-01-01

To find different types of glucosyltransferases (GTFs) produced by Leuconostoc mesenteroides strain Lm 28 and its mutant forms, and to check the effectiveness of gluco-oligosaccharide synthesis using maltose as the acceptor. Constitutive mutants were obtained after chemical mutagenesis by ethyl methane sulfonate. Lm M281 produced more active GTFs than that obtained by the parental strain cultivated on sucrose. GTF from Lm M286 produced a resistant glucan, based on endo-dextranase and amyloglucosidase hydrolysis. The extracellular enzymes from Lm M286 catalyse acceptor reactions and transfer the glucose unit from sucrose to maltose to produce gluco-oligosaccharides (GOS). By increasing the sucrose/maltose ratio, it was possible to catalyse the synthesis of oligosaccharides of increasing degree of polymerization (DP). Different types of GTFs (dextransucrase, alternansucrase and levansucrase) were produced from new constitutive mutants of Leuc. mesenteroides. GTFs from Lm M286 can catalyse the acceptor reaction in the presence of maltose, leading to the synthesis of branched oligosaccharides. Conditions were optimized to synthesize GOS by using GTFs from Lm M286, with the aim of producing maximum quantities of branched-chain oligosaccharides with DP 3-5. This would allow the use of the latter as prebiotics.

Gallid herpesvirus 3 SB-1 strain as a recombinant viral vector for poultry vaccination.

PubMed

Sadigh, Yashar; Powers, Claire; Spiro, Simon; Pedrera, Miriam; Broadbent, Andrew; Nair, Venugopal

2018-01-01

Live herpesvirus-vectored vaccines are widely used in veterinary medicine to protect against many infectious diseases. In poultry, three strains of herpesvirus vaccines are used against Marek's disease (MD). However, of these, only the herpesvirus of turkeys (HVT) has been successfully developed and used as a recombinant vaccine vector to induce protection against other avian viral diseases such as infectious bursal disease (IBD), Newcastle disease (ND) or avian influenza (AI). Although effective when administered individually, recombinant HVT vectors have limitations when combined in multivalent vaccines. Thus there is a need for developing additional viral vectors that could be combined with HVT in inducing protection against multiple avian diseases in multivalent vaccines. Gallid herpesvirus 3 (GaHV3) strain SB-1 is widely used by the poultry industry as bivalent vaccine in combination with HVT to exploit synergistic effects against MD. Here, we report the development and application of SB-1 as a vaccine vector to express the VP2 capsid antigen of IBD virus. A VP2 expression cassette was introduced into the SB-1 genome at three intergenic locations (UL3/UL4, UL10/UL11 and UL21/UL22) using recombineering methods on the full-length pSB-1 infectious clone of the virus. We show that the recombinant SB-1 vectors expressing VP2 induced neutralising antibody responses at levels comparable to that of commercial HVT-based VAXXITEK HVT+IBD vaccine. Birds vaccinated with the experimental recombinant SB-1 vaccine were protected against clinical disease after challenge with the very virulent UK661 IBDV isolate, demonstrating its value as an efficient viral vector for developing multivalent vaccines against avian diseases.

Paradox of vaccination: is vaccination really effective against avian flu epidemics?

PubMed

Iwami, Shingo; Suzuki, Takafumi; Takeuchi, Yasuhiro

2009-01-01

Although vaccination can be a useful tool for control of avian influenza epidemics, it might engender emergence of a vaccine-resistant strain. Field and experimental studies show that some avian influenza strains acquire resistance ability against vaccination. We investigated, in the context of the emergence of a vaccine-resistant strain, whether a vaccination program can prevent the spread of infectious disease. We also investigated how losses from immunization by vaccination imposed by the resistant strain affect the spread of the disease. We designed and analyzed a deterministic compartment model illustrating transmission of vaccine-sensitive and vaccine-resistant strains during a vaccination program. We investigated how the loss of protection effectiveness impacts the program. Results show that a vaccination to prevent the spread of disease can instead spread the disease when the resistant strain is less virulent than the sensitive strain. If the loss is high, the program does not prevent the spread of the resistant strain despite a large prevalence rate of the program. The epidemic's final size can be larger than that before the vaccination program. We propose how to use poor vaccines, which have a large loss, to maximize program effects and describe various program risks, which can be estimated using available epidemiological data. We presented clear and simple concepts to elucidate vaccination program guidelines to avoid negative program effects. Using our theory, monitoring the virulence of the resistant strain and investigating the loss caused by the resistant strain better development of vaccination strategies is possible.

Choice of High-Efficacy Strains for the Annual Influenza Vaccine

NASA Astrophysics Data System (ADS)

Deem, Michael

2005-03-01

We introduce a model of protein evolution to explain limitations in the immune system response to vaccination and disease [1]. The phenomenon of original antigenic sin, wherein vaccination creates memory sequences that can increase susceptibility to future exposures to the same disease, is explained as stemming from localization of the immune system response in antibody sequence space. This localization is a result of the roughness in sequence space of the evolved antibody affinity constant for antigen and is observed for diseases with high year-to-year mutation rates, such as influenza. We show that the order parameter within this theory correlates well with efficacies of the H3N2 influenza A component of the annual vaccine between 1971 and 2004 [2,3]. This new measure of antigenic distance predicts vaccine efficacy significantly more accurately than do current state-of-the-art phylogenetic sequence analyses or ferret antisera inhibition assays. We discuss how this new measure of antigenic distance may be used in the context of annual influenza vaccine design and monitoring of vaccine efficacy. 1) M. W. Deem and H. Y. Lee, Phys. Rev. Lett. 91 (2003) 068101. 2) E. T. Munoz and M. W. Deem,q-bio.BM/0408016. 3) V. Gupta, D. J. Earl, and M. W. Deem, ``Choice of High-Efficacy Strains for the Annual Influenza Vaccine,'' submitted.

Increased efficacy of inactivated vaccine candidates prepared with Salmonella enterica serovar Typhimurium strains of predominant genotypes in ducks.

PubMed

Youn, S Y; Kwon, Y K; Song, C S; Lee, H J; Jeong, O M; Choi, B K; Jung, S C; Kang, M S

2016-08-01

Salmonella enterica serovar Typhimurium has been a major causative agent of food-borne human disease, mainly due to consumption of contaminated food animal products. In particular, ducks serve as a reservoir of serovar Typhimurium, and are one of the common sources of human infection. To prevent infection of ducks, and therefore minimize human infection, it is critical to control the persistent epidemic strains in ducks. Here, we analyzed the genetic diversity and virulence of serovar Typhimurium isolates from ducks in Korea to identify the predominant strains that might be used as efficient vaccine candidates for ducks. Among the isolates, 2 representative isolates (ST26 and ST76) of predominant genotypes were selected as vaccine strains on the basis of genotypic analysis by pulsed-field gel electrophoresis and DNA microarrays. Two-week-old ducks were then injected intramuscularly with inactivated vaccine candidates prepared using ST26 or ST76 (10(8) cfu/0.5 mL/duck or 10(9) cfu/0.5 mL/duck), and oral challenge with a highly virulent serovar Typhimurium strain (10(9) cfu/0.5 mL/duck) was carried out 2 wk later. Shedding of the challenge strain was significantly decreased in group 2 after vaccination. The antibody levels by enzyme-linked immunosorbent assay in all vaccinated groups were enhanced significantly (P < 0.05) compared to the unvaccinated control group. Overall, vaccination with ST26 or ST76 reduced bacterial shedding and colonization in internal organs, and induced elevated antibody response. In particular, serovar Typhimurium ST26 (10(8) cfu/0.5 mL/duck) was the most effective vaccine candidate, which can provide efficient protection against serovar Typhimurium in ducks with higher effectiveness compared to a commercial vaccine currently used worldwide. © 2016 Poultry Science Association Inc.

Mechanical properties of elytra from Tribolium castaneum wild-type and body color mutant strains

USDA-ARS?s Scientific Manuscript database

Cuticle tanning in insects involves simultaneous cuticular hardening and pigmentation. The dynamic mechanical properties of the highly modified and cuticle-rich forewings (elytra) from Tribolium castaneum (red flour beetle) body color mutant strains were investigated to determine the relationship b...

Efficacy evaluation of the C-strain-based vaccines against the subgenotype 2.1d classical swine fever virus emerging in China.

PubMed

Luo, Yuzi; Ji, Shengwei; Lei, Jian-Lin; Xiang, Guang-Tao; Liu, Yan; Gao, Yao; Meng, Xing-Yu; Zheng, Guanglai; Zhang, En-Yu; Wang, Yimin; Du, Ming-Liang; Li, Yongfeng; Li, Su; He, Xi-Jun; Sun, Yuan; Qiu, Hua-Ji

2017-03-01

Classical swine fever (CSF) is a devastating infectious disease of pigs caused by classical swine fever virus (CSFV). The disease has been controlled following extensive vaccination with the lapinized attenuated vaccine C-strain for decades in China. However, frequent CSF outbreaks occurred recently in a large number of C-strain-vaccinated pig farms in China and a new subgenotype 2.1d of CSFV has been reported to be responsible for the outbreaks. Here we analyzed the molecular variations and antigenic differences among the C-strain-based commercial vaccines of different origins from different manufacturers in China, and reevaluated the vaccines against the emerging subgenotype 2.1d strain of CSFV. The results showed that the C-strain adapted to the continuous ST cell line (C ST ) contain a unique M290K variation on the E2 protein, compared to those of primary BT cells (C BT ) or rabbit origin (C RT ) and the traditional C-strain sequences available in the GenBank database. Serum neutralization test revealed the antigenic differences between C ST and C BT or C RT . Notably, the neutralizing titers of porcine anti-C-strain sera against the CSFV isolate of subgenotype 2.1d were significantly lower than those against C-strain or Shimen strain. The C-strain-vaccinated, subgenotype 2.1d HLJZZ2014 strain-challenged pigs did not show any clinical signs and all survived. However, these pigs displayed mild pathological and histological lesions, and the CSFV viral RNA was detected in the various tissue and blood samples. Taken together, the C-strain-based vaccines of different origins showed molecular variations and antigenic differences, and could provide clinical but not pathological and virological protection against the subgenotype 2.1d CSFV emerging in China. Further investigation is needed to comprehensively assess the efficacy of C-strain of different doses against the subgenotype 2.1d CSFV. Copyright © 2017 Elsevier B.V. All rights reserved.

Immune responses of bison and efficacy after booster vaccination with Brucella abortus strain RB51.

PubMed

Olsen, S C; McGill, J L; Sacco, R E; Hennager, S G

2015-04-01

Thirty-one bison heifers were randomly assigned to receive saline or a single vaccination with 10(10) CFU of Brucella abortus strain RB51. Some vaccinated bison were randomly selected for booster vaccination with RB51 at 11 months after the initial vaccination. Mean antibody responses to RB51 were greater (P < 0.05) in vaccinated bison after initial and booster vaccination than in nonvaccinated bison. The proliferative responses by peripheral blood mononuclear cells (PBMC) from the vaccinated bison were greater (P < 0.05) than those in the nonvaccinated bison at 16 and 24 weeks after the initial vaccination but not after the booster vaccination. The relative gene expression of gamma interferon (IFN-γ) was increased (P < 0.05) in the RB51-vaccinated bison at 8, 16, and 24 weeks after the initial vaccination and at 8 weeks after the booster vaccination. The vaccinated bison had greater (P < 0.05) in vitro production of IFN-γ at all sampling times, greater interleukin-1β (IL-1β) production in various samplings after the initial and booster vaccinations, and greater IL-6 production at one sampling time after the booster vaccination. Between 170 and 180 days of gestation, the bison were intraconjunctivally challenged with approximately 1 × 10(7) CFU of B. abortus strain 2308. The incidences of abortion and infection were greater (P < 0.05) in the nonvaccinated bison after experimental challenge than in the bison receiving either vaccination treatment. Booster-vaccinated, but not single-vaccinated bison, had a reduced (P < 0.05) incidence of infection in fetal tissues and maternal tissues compared to that in the controls. Compared to the nonvaccinated bison, both vaccination treatments lowered the colonization (measured as the CFU/g of tissue) of Brucella organisms in all tissues, except in retropharyngeal and supramammary lymph nodes. Our study suggests that RB51 booster vaccination is an effective vaccination strategy for enhancing herd immunity against

Immune Responses of Bison and Efficacy after Booster Vaccination with Brucella abortus Strain RB51

PubMed Central

McGill, J. L.; Sacco, R. E.; Hennager, S. G.

2015-01-01

Thirty-one bison heifers were randomly assigned to receive saline or a single vaccination with 1010 CFU of Brucella abortus strain RB51. Some vaccinated bison were randomly selected for booster vaccination with RB51 at 11 months after the initial vaccination. Mean antibody responses to RB51 were greater (P < 0.05) in vaccinated bison after initial and booster vaccination than in nonvaccinated bison. The proliferative responses by peripheral blood mononuclear cells (PBMC) from the vaccinated bison were greater (P < 0.05) than those in the nonvaccinated bison at 16 and 24 weeks after the initial vaccination but not after the booster vaccination. The relative gene expression of gamma interferon (IFN-γ) was increased (P < 0.05) in the RB51-vaccinated bison at 8, 16, and 24 weeks after the initial vaccination and at 8 weeks after the booster vaccination. The vaccinated bison had greater (P < 0.05) in vitro production of IFN-γ at all sampling times, greater interleukin-1β (IL-1β) production in various samplings after the initial and booster vaccinations, and greater IL-6 production at one sampling time after the booster vaccination. Between 170 and 180 days of gestation, the bison were intraconjunctivally challenged with approximately 1 × 107 CFU of B. abortus strain 2308. The incidences of abortion and infection were greater (P < 0.05) in the nonvaccinated bison after experimental challenge than in the bison receiving either vaccination treatment. Booster-vaccinated, but not single-vaccinated bison, had a reduced (P < 0.05) incidence of infection in fetal tissues and maternal tissues compared to that in the controls. Compared to the nonvaccinated bison, both vaccination treatments lowered the colonization (measured as the CFU/g of tissue) of Brucella organisms in all tissues, except in retropharyngeal and supramammary lymph nodes. Our study suggests that RB51 booster vaccination is an effective vaccination strategy for enhancing herd immunity against brucellosis in

Phenotypic characterization of 10 methanol oxidation mutant classes in Methylobacterium sp. strain AM1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nunn, D.N.; Lidstrom, M.E.

Twenty-five methanol oxidation mutants of the facultative methylotroph Methylobacterium sp. strain AM1 have been characterized by complementation analysis and assigned to 10 complementation groups, Mox A1, A2, A3, and B through H. In this study we have characterized each of the mutants belonging to the 10 Mox complementation groups for the following criteria: (i) phenazine methosulfate-dichlorophenolindophenol dye-linked methanol dehydrogenase activity; (ii) methanol-dependent whole-cell oxygen consumption; (iii) the presence or absence of methanol dehydrogenase protein by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blotting; (iv) the absorption spectra of purified mutant methanol dehydrogenase proteins; and (v) the presence or absence ofmore » the soluble cytochrome c proteins of Methylobacterium sp. strain AM1, as determined by reduced-oxidized difference spectra and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. With this information, we have proposed functions for each of the genes deficient in the mutants of the 10 Mox complementation groups. These proposed gene functions include two linked genes that encode the methanol dehydrogenase structural protein and the soluble cytochrome c/sub L/, a gene encoding a secretion function essential for the synthesis and export of methanol dehydrogenase and cytochrome c/sub L/, three gene functions responsible for the proper association of the pyrrolo-quinoline quinone prosthetic group with the methanol dehydrogenase apoprotein, and four positive regulatory gene functions controlling the expression of the ability to oxidize methanol.« less

Replication of transformation-defective mutants of the Prague strain of Rous sarcoma virus and isolation of a td mutant from duck-adapted PR-RSV-C.

PubMed

Geryk, J; Mazo, A; Svoboda, J; Hlozánek, I

1980-01-01

The replication of transformation-defective mutants of the Prague strain of Rous sarcoma virus subgroup C was studied using roller cultures. Under such conditions, 10(5)--10(6) infectous units of virus per 0.2 ml were produced, as revealed in both the reverse transcriptase and 16Q complementation tests. A new td daPR-RSV-C mutant was isolated from duck-adapted PR-RSV-C. This mutant replicated in roller cultures with equal efficiency as the original td PR-RSV-C. It was verified that td daPR-RSV-C does not transform chicken fibroblasts, is not oncogenic for 3-week-old chickens and has subgroup C host-range specificity. Both td mutants replicate in duck cells and reach the same titres.

Longitudinal 2 years field study of conventional vaccination against highly pathogenic avian influenza H5N1 in layer hens.

PubMed

Rudolf, Miriam; Pöppel, Manfred; Fröhlich, Andreas; Breithaupt, Angele; Teifke, Jens; Blohm, Ulrike; Mettenleiter, Thomas; Beer, Martin; Harder, Timm

2010-10-04

A licensed, inactivated vaccine based on a low pathogenic avian influenza virus strain (H5N2) was evaluated in layer hens kept under field conditions during a 2-year period. Vaccine efficacy was investigated by specific antibodies and by challenge-contact experiments using highly pathogenic avian influenza viruses (HPAIV) H5N1. Basic immunization with two applications induced clinical protection. Virus excretion by vaccinated hens was significantly reduced compared to non-vaccinated controls; transmission to non-vaccinated and vaccinated contact birds was not fully interrupted. Vaccination efficacy is influenced by several factors including antigenic relatedness between vaccine and field strains, but also by species, age and type of commercial uses of the host. Limitations and risks of HPAIV vaccination as silent spread of HPAIV and emergence of escape mutants must be considered a priori and appropriate corrective measures have to be installed. Copyright © 2010 Elsevier Ltd. All rights reserved.

A Y527A mutation in the fusion protein of Newcastle disease virus strain LaSota leads to a hyperfusogenic virus with increased replication and immunogenicity.

PubMed

Manoharan, Vinoth K; Khattar, Sunil K; Paldurai, Anandan; Kim, Shin-Hee; Samal, Siba K

2016-02-01

Newcastle disease is a highly contagious and economically important disease of poultry. Low-virulence Newcastle disease virus (NDV) strains such as B1 and LaSota have been used as live vaccines, with a proven track record of safety and efficacy. However, these vaccines do not completely prevent infection or virus shedding. Therefore, there is a need to enhance the immunogenicity of these vaccine strains. In this study, the effect of mutations in the conserved tyrosine residues of the F protein of vaccine strain LaSota was investigated. Our results showed that substitution of tyrosine at position 527 by alanine resulted in a hyperfusogenic virus with increased replication and immunogenicity. Challenge study with highly virulent NDV strain Texas GB showed that immunization of chickens with Y527A mutant virus provided 100% protection and no shedding of the challenge virus. This study suggests that the strain LaSota harbouring the Y527A mutation may represent a more efficacious vaccine.

Deficiency of gustatory sensitivity to some deterrent compounds in "polyphagous" mutant strains of the silkworm, Bombyx mori.

PubMed

Asaoka, K

2000-11-01

Sawa-J, CSJ02 and N601 x C601 are selected mutant strains of Bombyx mori, which grow on various artificial diets or temporarily ingest various plant leaves. To examine the mechanisms mediating diet breadth of caterpillars, gustatory spike responses of the silkworms, called 'polyphagous" strains, were compared with normal strains, N137 x C146 and C02. There were notable differences in their feeding habits and in their sensitivity to salicin in deterrent cells in the maxillary medial styloconic sensilla and the epipharyngeal sensilla. By contrast, the deterrent cells of all strains responded similarly to strychnine nitrate in a dose-dependent manner. In additional comparisons of Sawa-J and N137 x C146, Sawa-J maxillary deterrent cells were significantly less sensitive to phloridzin, amygdalin and arbutin, but responded to some alkaloids and 20-hydroxyecdysone with similar or even higher firing rate. These results suggest that the deficiency of the sensitivity to some deterrent compounds on the deterrent cell of the polyphagous strains may be caused by mutant genes and affects the diet breadth of caterpillars.

Antibody induced by immunization with the Jeryl Lynn mumps vaccine strain effectively neutralizes a heterologous wild-type mumps virus associated with a large outbreak.

PubMed

Rubin, Steven A; Qi, Li; Audet, Susette A; Sullivan, Bradley; Carbone, Kathryn M; Bellini, William J; Rota, Paul A; Sirota, Lev; Beeler, Judy

2008-08-15

Recent mumps outbreaks in older vaccinated populations were caused primarily by genotype G viruses, which are phylogenetically distinct from the genotype A vaccine strains used in the countries affected by the outbreaks. This finding suggests that genotype A vaccine strains could have reduced efficacy against heterologous mumps viruses. The remote history of vaccination also suggests that waning immunity could have contributed to susceptibility. To examine these issues, we obtained consecutive serum samples from children at different intervals after vaccination and assayed the ability of these samples to neutralize the genotype A Jeryl Lynn mumps virus vaccine strain and a genotype G wild-type virus obtained during the mumps outbreak that occurred in the United States in 2006. Although the geometric mean neutralizing antibody titers against the genotype G virus were approximately one-half the titers measured against the vaccine strain, and although titers to both viruses decreased with time after vaccination, antibody induced by immunization with the Jeryl Lynn mumps vaccine strain effectively neutralized the outbreak-associated virus at all time points tested.

Evaluation of the use of various rat strains for immunogenic potency tests of Sabin-derived inactivated polio vaccines.

PubMed

Someya, Yuichi; Ami, Yasushi; Takai-Todaka, Reiko; Fujimoto, Akira; Haga, Kei; Murakami, Kosuke; Fujii, Yoshiki; Shirato, Haruko; Oka, Tomoichiro; Shimoike, Takashi; Katayama, Kazuhiko; Wakita, Takaji

2018-03-01

Slc:Wistar rats have been the only strain used in Japan for purpose of evaluating a national reference vaccine for the Sabin-derived inactivated polio vaccine (sIPV) and the immunogenicity of sIPV-containing products. However, following the discovery that the Slc:Wistar strain was genetically related to the Fischer 344 strain, other "real" Wistar strains, such as Crlj:WI, that are available worldwide were tested in terms of their usefulness in evaluating the immunogenicity of the past and current lots of a national reference vaccine. The response of the Crlj:WI rats against the serotype 1 of sIPV was comparable to that of the Slc:Wistar rats, while the Crlj:WI rats exhibited a higher level of response against the serotypes 2 and 3. The immunogenic potency units of a national reference vaccine determined using the Slc:Wistar rats were reproduced on tests using the Crlj:WI rats. These results indicate that a titer of the neutralizing antibody obtained in response to a given dose of sIPV cannot be directly compared between these two rat strains, but that, more importantly, the potency units are almost equivalent for the two rat strains. Copyright © 2018 International Alliance for Biological Standardization. Published by Elsevier Ltd. All rights reserved.

Increase in Genetic Diversity of Haemophilus influenzae Serotype b (Hib) Strains after Introduction of Hib Vaccination in The Netherlands

PubMed Central

Schouls, Leo M.; van der Ende, Arie; van de Pol, Ingrid; Schot, Corrie; Spanjaard, Lodewijk; Vauterin, Paul; Wilderbeek, Dorus; Witteveen, Sandra

2005-01-01

Recently, there has been an increase in The Netherlands in the number of cases of invasive disease caused by Haemophilus influenzae serotype b (Hib). To study a possible change in the Hib population that could explain the rise in incidence, a multiple-locus variable number tandem repeats analysis (MLVA) was developed to genotype H. influenzae isolates. The MLVA enabled the differentiation of H. influenzae serotype b strains with higher discriminatory power than multilocus sequence typing (MLST). MLVA profiles of noncapsulated H. influenzae and H. influenzae serotype f strains were more heterogeneous than serotype b strains and were distinct from Hib, although some overlap occurred. The MLVA was used to genotype a collection of 520 H. influenzae serotype b strains isolated from patients in The Netherlands with invasive disease. The strains were collected from 1983 from 2002, covering a time period of 10 years before and 9 years after the introduction of the Hib vaccine in the Dutch national vaccination program. MLVA revealed a sharp increase in genetic diversity of Hib strains isolated from neonates to 4-year-old patients after 1993, when the Hib vaccine was introduced. Hib strains isolated from patients older than 4 years in age were genetically diverse, and no significant change in diversity was seen after the introduction of the vaccine. These observations suggest that after the introduction of the Hib vaccine young children no longer constitute the reservoir for Hib and that they are infected by adults carrying genetically diverse Hib strains. PMID:15956392

Transmission of Hemagglutinin D222G Mutant Strain of Pandemic (H1N1) 2009 Virus

PubMed Central

Facchini, Marzia; Spagnolo, Domenico; De Marco, Maria A.; Calzoletti, Laura; Zanetti, Alessandro; Fumagalli, Roberto; Tanzi, Maria L.; Cassone, Antonio; Rezza, Giovanni; Donatelli, Isabella

2010-01-01

A pandemic (H1N1) 2009 virus strain carrying the D222G mutation was identified in a severely ill man and was transmitted to a household contact. Only mild illness developed in the contact, despite his obesity and diabetes. The isolated virus reacted fully with an antiserum against the pandemic vaccine strain. PMID:20409386

Monitoring of canine parvovirus (CPV) strains detected in vaccinated puppies in Brazil.

PubMed

Castro, T X; Costa, E M; Leite, J P; Labarthe, N V; Cubel Garcia, R C N

2011-04-01

The objective of this study was to investigate, by partial sequencing of VP2 protein, the variability of CPV detected in 37 fecal samples collected from vaccinated puppies with enteritis. Laboratorial diagnosis of CPV was confirmed by HA/HI and PCR and, for sequencing analyses, two different regions of the VP2 gene were amplified by PCR. From 1995 to 2004, all strains were characterized as CPV-2a. After that, both CPV-2a and CPV-2b were detected. All CPV-2a showed a non-synonymous mutation in the residue 297 (Ser→Ala). A synonymous substitution at the AA 574 was also observed in 15/37 samples. Our findings indicate that the cases of vaccine failure are most likely not associated to the mutations detected in the sequenced regions. However, the monitoring of genotyping mutations that led to new CPV strains is essential to determinate if current vaccines will keep providing protection against all new future variants. Copyright © 2010 Elsevier Ltd. All rights reserved.

A national reference for inactivated polio vaccine derived from Sabin strains in Japan.

PubMed

Shirato, Haruko; Someya, Yuichi; Ochiai, Masaki; Horiuchi, Yoshinobu; Takahashi, Motohide; Takeda, Naokazu; Wakabayashi, Kengo; Ouchi, Yasumitsu; Ota, Yoshihiro; Tano, Yoshio; Abe, Shinobu; Yamazaki, Shudo; Wakita, Takaji

2014-09-08

As one aspect of its campaign to eradicate poliomyelitis, the World Health Organization (WHO) has encouraged development of the inactivated polio vaccine (IPV) derived from the Sabin strains (sIPV) as an option for an affordable polio vaccine, especially in low-income countries. The Japan Poliomyelitis Research Institute (JPRI) inactivated three serotypes of the Sabin strains and made sIPV preparations, including serotypes 1, 2 and 3 D-antigens in the ratio of 3:100:100. The National Institute of Infectious Diseases, Japan, assessed the immunogenic stability of these sIPV preparations in a rat potency test, according to an evaluation method recommended by the WHO. The immunogenicity of the three serotypes was maintained for at least 4 years when properly stored under -70°C. Based on these data, the sIPV preparations made by JPRI have been approved as national reference vaccines by the Japanese national control authority and used for the quality control of the tetracomponent sIPV-containing diphtheria-tetanus-acellular pertussis combination vaccines that were licensed for a routine polio immunization in Japan. Copyright © 2014 Elsevier Ltd. All rights reserved.

Molecular characteristics of Polish field strains of Marek's disease herpesvirus isolated from vaccinated chickens

PubMed Central

2011-01-01

Background Twenty-nine Marek's disease virus (MDV) strains were isolated during a 3 year period (2007-2010) from vaccinated and infected chicken flocks in Poland. These strains had caused severe clinical symptoms and lesions. In spite of proper vaccination with mono- or bivalent vaccines against Marek's disease (MD), the chickens developed symptoms of MD with paralysis. Because of this we decided to investigate possible changes and mutations in the field strains that could potentially increase their virulence. We supposed that such mutations may have been caused by recombination with retroviruses of poultry - especially reticuloendotheliosis virus (REV). Methods In order to detect the possible reasons of recent changes in virulence of MDV strains, polymerase chain reaction (PCR) analyses for meq oncogene and for long-terminal repeat (LTR) region of REV were conducted. The obtained PCR products were sequenced and compared with other MDV and REV strains isolated worldwide and accessible in the GeneBank database. Results Sequencing of the meq oncogene showed a 68 basepair insertion and frame shift within 12 of 24 field strains. Interestingly, the analyses also showed 0.78, 0.8, 0.82, 1.6 kb and other random LTR-REV insertions into the MDV genome in 28 of 29 of strains. These genetic inserts were present after passage in chicken embryo kidney cells suggesting LTR integration into a non-functional region of the MDV genome. Conclusion The results indicate the presence of a recombination between MDV and REV under field conditions in Polish chicken farms. The genetic changes within the MDV genome may influence the virus replication and its features in vivo. However, there is no evidence that meq alteration and REV insertions are related to the strains' virulence. PMID:21320336

Evaluation of Recombinant Attenuated Salmonella Vaccine Strains for Broad Protection against Extraintestinal Pathogenic Escherichia coli.

PubMed

Maddux, Jacob T; Stromberg, Zachary R; Curtiss Iii, Roy; Mellata, Melha

2017-01-01

Antibiotic-resistant bacterial infections are difficult to treat, producing a burden on healthcare and the economy. Extraintestinal pathogenic Escherichia coli (ExPEC) strains frequently carry antibiotic resistance genes, cause infections outside of the intestine, and are causative agents of hospital-acquired infections. Developing a prevention strategy against this pathogen is challenging due to its antibiotic resistance and antigenic diversity. E. coli common pilus (ECP) is frequently found in ExPEC strains and may serve as a common antigen to induce protection against several ExPEC serotypes. In addition, live recombinant attenuated Salmonella vaccine (RASV) strains have been used to prevent Salmonella infection and can also be modified to deliver foreign antigens. Thus, the objective of this study was to design a RASV to produce ECP on its surface and assess its ability to provide protection against ExPEC infections. To constitutively display ECP in a RASV strain, we genetically engineered a vector (pYA4428) containing aspartate-β-semialdehyde dehydrogenase and E. coli ecp genes and introduced it into RASV χ9558. RASV χ9558 containing an empty vector (pYA3337) was used as a control to assess protection conferred by the RASV strain without ECP. We assessed vaccine efficacy in in vitro bacterial inhibition assays and mouse models of ExPEC-associated human infections. We found that RASV χ9558(pYA4428) synthesized the major pilin (EcpA) and tip pilus adhesin (EcpD) on the bacterial surface. Mice orally vaccinated with RASV χ9558(pYA3337) without ECP or χ9558(pYA4428) with ECP, produced anti- Salmonella LPS and anti- E. coli EcpA and EcpD IgG and IgA antibodies. RASV strains showed protective potential against some E. coli and Salmonella strains as assessed using in vitro assays. In mouse sepsis and urinary tract infection challenge models, both vaccines had significant protection in some internal organs. Overall, this work showed that RASVs can elicit an

Immune protection of chickens conferred by a vaccine consisting of attenuated strains of Salmonella Enteritidis, Typhimurium and Infantis.

PubMed

Varmuzova, Karolina; Faldynova, Marcela; Elsheimer-Matulova, Marta; Sebkova, Alena; Polansky, Ondrej; Havlickova, Hana; Sisak, Frantisek; Rychlik, Ivan

2016-10-15

The colonization of poultry with different Salmonella enterica serovars poses an issue throughout the world. In this study we therefore tested the efficacy of a vaccine consisting of attenuated strains of Salmonella enterica serovars Enteritidis, Typhimurium and Infantis against challenge with the same serovars and with S. Agona, Dublin and Hadar. We tested oral and aerosol administration of the vaccine, with or without co-administration of cecal microbiota from adult hens. The protective effect was determined by bacterial counts of the challenge strains up to week 18 of life and by characterizing the immune response using real-time PCR specific for 16 different genes. We have shown that a vaccine consisting of attenuated S. Enteritidis, S. Typhimurium and S. Infantis protected chickens against challenge with the wild type strains of the same serovars and partially protected chickens also against challenge with isolates belonging to serovars Dublin or Hadar. Aerosol vaccination was more effective at inducing systemic immunity whilst oral vaccination stimulated a local immune response in the gut. Co-administration of cecal microbiota increased the protectiveness in the intestinal tract but slightly decreased the systemic immune response. Adjusting the vaccine composition and changing the administration route therefore affects vaccine efficacy.

New Strains Intended for the Production of Inactivated Polio Vaccine at Low-Containment After Eradication

PubMed Central

Knowlson, Sarah; Burlison, John; Giles, Elaine; Fox, Helen; Macadam, Andrew J.; Minor, Philip D.

2015-01-01

Poliomyelitis has nearly been eradicated through the efforts of the World Health Organization’s Global Eradication Initiative raising questions on containment of the virus after it has been eliminated in the wild. Most manufacture of inactivated polio vaccines currently requires the growth of large amounts of highly virulent poliovirus, and release from a production facility after eradication could be disastrous; WHO have therefore recommended the use of the attenuated Sabin strains for production as a safer option although it is recognised that they can revert to a transmissible paralytic form. We have exploited the understanding of the molecular virology of the Sabin vaccine strains to design viruses that are extremely genetically stable and hyperattenuated. The viruses are based on the type 3 Sabin vaccine strain and have been genetically modified in domain V of the 5’ non-coding region by changing base pairs to produce a cassette into which capsid regions of other serotypes have been introduced. The viruses give satisfactory yields of antigenically and immunogenically correct viruses in culture, are without measurable neurovirulence and fail to infect non-human primates under conditions where the Sabin strains will do so. PMID:26720150

New Strains Intended for the Production of Inactivated Polio Vaccine at Low-Containment After Eradication.

PubMed

Knowlson, Sarah; Burlison, John; Giles, Elaine; Fox, Helen; Macadam, Andrew J; Minor, Philip D

2015-12-01

Poliomyelitis has nearly been eradicated through the efforts of the World Health Organization's Global Eradication Initiative raising questions on containment of the virus after it has been eliminated in the wild. Most manufacture of inactivated polio vaccines currently requires the growth of large amounts of highly virulent poliovirus, and release from a production facility after eradication could be disastrous; WHO have therefore recommended the use of the attenuated Sabin strains for production as a safer option although it is recognised that they can revert to a transmissible paralytic form. We have exploited the understanding of the molecular virology of the Sabin vaccine strains to design viruses that are extremely genetically stable and hyperattenuated. The viruses are based on the type 3 Sabin vaccine strain and have been genetically modified in domain V of the 5' non-coding region by changing base pairs to produce a cassette into which capsid regions of other serotypes have been introduced. The viruses give satisfactory yields of antigenically and immunogenically correct viruses in culture, are without measurable neurovirulence and fail to infect non-human primates under conditions where the Sabin strains will do so.

Secreted Expression of the Cap Gene of Porcine Circovirus Type 2 in Classical Swine Fever Virus C-Strain: Potential of C-Strain Used as a Vaccine Vector.

PubMed

Zhang, Lingkai; Li, Yongfeng; Xie, Libao; Wang, Xiao; Gao, Xulei; Sun, Yuan; Qiu, Hua-Ji

2017-10-16

Bivalent vaccines based on live attenuated viruses expressing a heterologous protein are an attractive strategy to address co-infections with various pathogens in the field. Considering the excellent efficacy and safety of the lapinized live attenuated vaccine C-strain (HCLV strain) of classical swine fever virus (CSFV), we proposed that C-strain has the potential as a viral vector for developing bivalent vaccines. To this end, we generated three recombinant viruses based on C-strain, one expressing the capsid ( Cap ) gene of porcine circovirus type 2 (PCV2) with the nuclear localization signal (NLS) (rHCLV-2ACap), and the other two expressing the PCV2 Cap gene without the NLS yet containing the signal peptide of the prolactin gene (rHCLV-pspCap) or that of the ubiquitin-specific peptidase gene (rHCLV-uspCap). All the recombinant viruses exhibited phenotypes similar to those of the parental virus and produced high-level anti-CSFV neutralizing antibodies (NAbs) in rabbits. Interestingly, rHCLV-uspCap and rHCLV-pspCap, but not rHCLV-2ACap, elicited detectable anti-Cap and -PCV2 NAbs in rabbits. Taken together, our data demonstrate that C-strain can be used as a viral vector to develop bivalent vaccines.

Secreted Expression of the Cap Gene of Porcine Circovirus Type 2 in Classical Swine Fever Virus C-Strain: Potential of C-Strain Used as a Vaccine Vector

PubMed Central

Zhang, Lingkai; Li, Yongfeng; Xie, Libao; Wang, Xiao; Gao, Xulei; Sun, Yuan; Qiu, Hua-Ji

2017-01-01

Bivalent vaccines based on live attenuated viruses expressing a heterologous protein are an attractive strategy to address co-infections with various pathogens in the field. Considering the excellent efficacy and safety of the lapinized live attenuated vaccine C-strain (HCLV strain) of classical swine fever virus (CSFV), we proposed that C-strain has the potential as a viral vector for developing bivalent vaccines. To this end, we generated three recombinant viruses based on C-strain, one expressing the capsid (Cap) gene of porcine circovirus type 2 (PCV2) with the nuclear localization signal (NLS) (rHCLV-2ACap), and the other two expressing the PCV2 Cap gene without the NLS yet containing the signal peptide of the prolactin gene (rHCLV-pspCap) or that of the ubiquitin-specific peptidase gene (rHCLV-uspCap). All the recombinant viruses exhibited phenotypes similar to those of the parental virus and produced high-level anti-CSFV neutralizing antibodies (NAbs) in rabbits. Interestingly, rHCLV-uspCap and rHCLV-pspCap, but not rHCLV-2ACap, elicited detectable anti-Cap and -PCV2 NAbs in rabbits. Taken together, our data demonstrate that C-strain can be used as a viral vector to develop bivalent vaccines. PMID:29035292

Construction of a quadruple auxotrophic mutant of an industrial polyploid saccharomyces cerevisiae strain by using RNA-guided Cas9 nuclease.

PubMed

Zhang, Guo-Chang; Kong, In Iok; Kim, Heejin; Liu, Jing-Jing; Cate, Jamie H D; Jin, Yong-Su

2014-12-01

Industrial polyploid yeast strains harbor numerous beneficial traits but suffer from a lack of available auxotrophic markers for genetic manipulation. Here we demonstrated a quick and efficient strategy to generate auxotrophic markers in industrial polyploid yeast strains with the RNA-guided Cas9 nuclease. We successfully constructed a quadruple auxotrophic mutant of a popular industrial polyploid yeast strain, Saccharomyces cerevisiae ATCC 4124, with ura3, trp1, leu2, and his3 auxotrophies through RNA-guided Cas9 nuclease. Even though multiple alleles of auxotrophic marker genes had to be disrupted simultaneously, we observed knockouts in up to 60% of the positive colonies after targeted gene disruption. In addition, growth-based spotting assays and fermentation experiments showed that the auxotrophic mutants inherited the beneficial traits of the parental strain, such as tolerance of major fermentation inhibitors and high temperature. Moreover, the auxotrophic mutants could be transformed with plasmids containing selection marker genes. These results indicate that precise gene disruptions based on the RNA-guided Cas9 nuclease now enable metabolic engineering of polyploid S. cerevisiae strains that have been widely used in the wine, beer, and fermentation industries. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Nanogram quantities of a DNA vaccine protect rainbow trout fry against heterologous strains of infectious hematopoietic necrosis virus

USGS Publications Warehouse

Corbeil, S.; LaPatra, S.E.; Anderson, E.D.; Kurath, G.

2000-01-01

The efficacy of a DNA vaccine containing the glycoprotein gene of infectious hematopoietic necrosis virus (IHNV), a rhabdovirus affecting trout and salmon, was investigated. The minimal dose of vaccine required, the protection against heterologous strains, and the titers of neutralizing antibodies produced were used to evaluate the potential of the vaccine as a control pharmaceutical. Results indicated that a single dose of as little as 1–10 ng of vaccine protected rainbow trout fry against waterborne challenge by IHNV. An optimal dose of 100 ng per fish was selected to assure strong protection under various conditions. Neutralizing antibody titers were detected in fish vaccinated with concentrations of DNA ranging from 5 to 0.01 μg. Furthermore, the DNA vaccine protected fish against a broad range of viral strains from different geographic locations, including isolates from France and Japan, suggesting that the vaccine could be used worldwide. A single dose of this DNA vaccine induced protection in fish at a lower dose than is usually reported in mammalian DNA vaccine studies.

[The primary structure of a vaccine strain of tobacco mosaic virus V-69].

PubMed

Shiian, A N; Mil'shina, N V; Snegireva, P B; Pukhal'skiĭ, V A

1994-12-01

A random set of cDNA fragments were synthesized on genomic RNA of TMV vaccine strain V-69, using random primers and reverse transcriptase. Following synthesis of double-stranded cDNA, they were cloned into the pUC-19 plasmid; and 28 clones were sequenced (insert size 100-500 bp). High nucleotide sequence homology of V-69 (more than 95%) was shown only with tomato strain TMV-L [1]. Sequenced clones represent 54% of the genome (50% of the replicase gene, 98% of the transport protein gene, and 60% of the coat protein gene). In this genome region, 24 base substitutions were revealed, as compared to the wild-type TMV-L sequence. Six base substitutions resulted in changes in corresponding amino acid codons. No substitutions coincided with those discovered in the related TMV vaccine strain L11A [2], while two substitutions in the replicase gene were identical to those found in TMV strain Lta1 [3], which is capable of overcoming protection in tomatoes with the resistance gene Tm-1.

Phylogenetic Analysis of Theileria annulata Infected Cell Line S15 Iran Vaccine Strain.

PubMed

Habibi, Gh

2012-01-01

Bovine theileriosis results from infection with obligate intracellular protozoa of the genus Theileria. The phylogenetic relationships between two isolates of Theileria annulata, and 36 Theileria spp., as well as 6 outgroup including Babesia spp. and coccidian protozoa were analyzed using the 18S rRNA gene sequence. The target DNA segment was amplified by PCR. The PCR product was used for direct sequencing. The length of the 18S rRNA gene of all Theileria spp. involved in this study was around 1,400 bp. A phylogenetic tree was inferred based on the 18S rRNA gene sequence of the Iran and Iraq isolates, and other species of Theileria available in GenBank. In the constructed tree, Theileria annulata (Iran vaccine strain) was closely related to other T. annulata from Europe, Asia, as well as T. lestoquardi, T. parva and T. taurotragi all in one clade. Phylogenetic analyses based on small subunit ribosomal RNA gene suggested that the percent identity of the sequence of Iran vaccine strain was completely the same as Iraq sequence (100% identical), but the similarity of Iran vaccine strain with other T. annulata reported from China, Spain and Italy determined the 97.9 to 99.9% identity.

Immunogenicity and safety of a novel MMR vaccine (live, freeze-dried) containing the Edmonston-Zagreb measles strain, the Hoshino mumps strain, and the RA 27/3 rubella strain: Results of a randomized, comparative, active controlled phase III clinical trial.

PubMed

Sood, Ashwani; Mitra, Monjori; Joshi, Himanshu Arvind; Nayak, Uma Siddhartha; Siddaiah, Prashanth; Babu, T Ramesh; Mahapatro, Samarendra; Sanmukhani, Jayesh; Gupta, Gaurav; Mittal, Ravindra; Glueck, Reinhard

2017-07-03

This phase III clinical trial was conducted to evaluate the immunogenicity and safety of the single-dose and multi-dose formulations of a novel MMR vaccine (live, freeze-dried) developed by M/s Cadila Healthcare Limited, India (Cadila MMR vaccine), containing the Hoshino mumps strain, compared to that of an existing MMR vaccine (live, freeze-dried) developed by M/s Serum Institute of India Limited, India (Serum MMR vaccine). These two vaccines have similar measles and rubella strains, but different mumps strains (Hoshino in Cadila MMR vaccine, and L-Zagreb in Serum MMR vaccine). Three hundred and twenty-eight subjects of either sex, aged 15-18 months, were randomized in a 2:1 ratio to receive either the Cadila or Serum MMR vaccine. Immunogenicity assessments (IgG antibodies against measles, mumps, and rubella viruses) were done at baseline and 42 d after vaccination. Solicited (local and systemic) and unsolicited adverse events were recorded for up to 42 d following vaccination. The Cadila MMR vaccine was found to be non-inferior to the Serum MMR vaccine in terms of end-of-study proportion of subjects seropositive for anti-measles antibodies (100.0% in both groups), anti-mumps antibodies (94.5% vs. 94.0%), and anti-rubella antibodies (95.5% vs. 91.0%). Both vaccines were well tolerated by all study participants; the most common adverse event reported in both groups was fever, followed by rash. The results of this phase III clinical trial show that the novel Cadila MMR vaccine is non-inferior to the Serum MMR vaccine.

Marker vaccine strategies and candidate CSFV marker vaccines.

PubMed

Dong, Xiao-Nan; Chen, Ying-Hua

2007-01-04

Classical swine fever (CSF) is an economically important highly contagious disease of swine worldwide. Classical swine fever virus (CSFV) is its etiological agent, and the only natural hosts are domestic pigs and wild boars. Although field CSFV strains vary in the virulence, they all result in serious losses in pig industry. Highly virulent field strains generally cause acute disease and high mortality; moderately virulent field strains raise subacute or chronic infections; postnatal infection by low virulent field strains produces subclinical infection and mortality in the new-born piglets. CSFV can cross the placental barrier, and this transplacental transmission usually results in mortality of fetuses and birth of congenitally infected pigs with a late-onset disease and death. Two main strategies to control CSF epidemic are systematic prophylactic vaccination with live attenuated vaccines (such as C-strain) and non-vaccination stamping-out policy. But neither of them is satisfying enough. Marker vaccine and companion serological diagnostic test is thought to be a promising strategy for future control and eradication of CSF. During the past 15 years, various candidate marker vaccines were constructed and evaluated in the animal experiments, including recombinant chimeric vaccines, recombinant deletion vaccines, DNA vaccines, subunit vaccines and peptide vaccines. Among them, two subunit vaccines entered the large scale marker vaccine trial of EU in 1999. Although they failed to fulfil all the demands of the Scientific Veterinary Committee, they successfully induced solid immunity against CSFV in the vaccinated pigs. It can be expected that new potent marker vaccines might be commercially available and used in systematic prophylactic vaccination campaign or emergency vaccination in the next 15 years. Here, we summarized current strategies and candidate CSFV marker vaccines. These strategies and methods are also helpful for the development of new

Physiology, pathogenicity and immunogenicity of live, attenuated Salmonella enterica serovar Enteritidis mutants in chicks.

PubMed

Si, Wei; Wang, Xiumei; Liu, Huifang; Yu, Shenye; Li, Zhaoli; Chen, Liping; Zhang, Wanjiang; Liu, Siguo

2015-01-01

To construct a novel live, attenuated Salmonella vaccine, the lon, cpxR and cpdB genes were deleted from a wild-type Salmonella enterica serovar Enteritidis-6 (SM-6) strain using the phage λ Red homologous recombination system, resulting in SM-△CpxR, SM-△C/Lon and SM-△C/L/CpdB. The growth curves of strain SM-△C/Lon grew more rapidly than the other strains and had OD 600 values higher than the other strains starting at the 4 h time point. The growth curves of strain SM-△C/L/CpdB were relatively flat. The colonization time of SM-△C/L/CpdB is about 8-10 days. Deleting the lon/cpxR/cpdB (SM-6) genes resulted in an approximate 10(3)-fold attenuation in virulence assessed by the analysis of the LD50 of specific pathogen-free (SPF) chicks. This result indicated that the deletion of the lon, cpxR and cpdB genes induced significant virulence attenuation. The protective effects of SM-△C/L/CpdB vaccination in SPF chicks against 5 × 10(9) colony forming units (CFU) of S. Enteritidis were resulted from the induction of an effective immune response. These findings demonstrate the potential of mutant SM-△C/L/CpdB to be used as an effective vaccine. Copyright © 2015 Elsevier Ltd. All rights reserved.

Modification of glucose import capacity in Escherichia coli: physiologic consequences and utility for improving DNA vaccine production

PubMed Central

2013-01-01

Background The bacterium Escherichia coli can be grown employing various carbohydrates as sole carbon and energy source. Among them, glucose affords the highest growth rate. This sugar is nowadays widely employed as raw material in industrial fermentations. When E. coli grows in a medium containing non-limiting concentrations of glucose, a metabolic imbalance occurs whose main consequence is acetate secretion. The production of this toxic organic acid reduces strain productivity and viability. Solutions to this problem include reducing glucose concentration by substrate feeding strategies or the generation of mutant strains with impaired glucose import capacity. In this work, a collection of E. coli strains with inactive genes encoding proteins involved in glucose transport where generated to determine the effects of reduced glucose import capacity on growth rate, biomass yield, acetate and production of an experimental plasmid DNA vaccine (pHN). Results A group of 15 isogenic derivatives of E. coli W3110 were generated with single and multiple deletions of genes encoding glucose, mannose, beta-glucoside, maltose and N-acetylglucosamine components of the phosphoenolpyruvate:sugar phosphotransferase system (PTS), as well as the galactose symporter and the Mgl galactose/glucose ABC transporter. These strains were characterized by growing them in mineral salts medium supplemented with 2.5 g/L glucose. Maximum specific rates of glucose consumption (qs) spanning from 1.33 to 0.32 g/g h were displayed by the group of mutants and W3110, which resulted in specific growth rates ranging from 0.65-0.18 h-1. Acetate accumulation was reduced or abolished in cultures with all mutant strains. W3110 and five selected mutant derivatives were transformed with pHN. A 3.2-fold increase in pHN yield on biomass was observed in cultures of a mutant strain with deletion of genes encoding the glucose and mannose PTS components, as well as Mgl. Conclusions The group of E. coli mutants

Evaluation of European tick-borne encephalitis virus vaccine against recent Siberian and far-eastern subtype strains.

PubMed

Hayasaka, D; Goto, A; Yoshii, K; Mizutani, T; Kariwa, H; Takashima, I

2001-09-14

To evaluate the efficacy of the European TBE vaccine in east-Siberian and far-eastern regions of Russia, we examined the immune responses of the vaccine against recent TBE virus Siberian (Irkutsk) and far-eastern (Khabarovsk and Vladivostok) isolates. The sera of vaccinated humans showed efficient neutralizing antibody titers (> or =20) against Siberian and far-eastern strains. To evaluate the efficacy of the vaccine in vivo, mice were vaccinated and challenged with lethal doses of the viruses. All vaccinated mice survived each virus challenge. These results suggest that the European vaccine can prevent the TBE virus infection in east-Siberian and far-eastern regions of Russia.

A vaccine strain of pseudorabies virus with deletions in the thymidine kinase and glycoprotein X genes.

PubMed

Marchioli, C C; Yancey, R J; Wardley, R C; Thomsen, D R; Post, L E

1987-11-01

A pseudorabies virus (PRV) mutant with deletions in genes for glycoprotein X (gX) and thymidine kinase, designated delta GX delta TK, was constructed and evaluated as a vaccine for protecting swine against PRV-induced mortality. Doses greater than or equal to 10(3) plaque-forming units (PFU) of this strain given to mice provided protection from challenge exposure with virulent PRV. Sera tested from mice inoculated with delta GX delta TK had high titers of neutralizing antibody to PRV, but reactivity in the same sera was not significantly different from that in sera from noninoculated mice (controls) when sera from both groups were evaluated by use of an ELISA with gX antigen produced in Escherichia coli. Compared with noninoculated pigs (controls), those given delta GX delta TK (greater than or equal to 10(2) PFU) were protected completely from lethal challenge exposure, without experiencing adverse effects on weight gain and with reduction of shedding of virulent challenge virus. Serotest results indicated that, although inoculated pigs responded with strong neutralizing antibody titers, the response of delta GX delta TK-inoculated pigs to gX, as determined by ELISA before challenge exposure, was not significantly greater than the ELISA values obtained from control pigs. The ELISA values from a group of pigs inoculated with a commercially available vaccine were significantly (P less than 0.05) higher than those of control pigs. The experimental vaccine, delta GX delta TK, was avirulent for mice, swine, and sheep, but was mildly virulent for calves (mortality, 1 of 12) and more virulent for dogs (mortality, 3 of 6) and cats (mortality, 2 of 6).(ABSTRACT TRUNCATED AT 250 WORDS)

Diagnostic tools based on minor groove binder probe technology for rapid identification of vaccinal and field strains of canine parvovirus type 2b.

PubMed

Decaro, Nicola; Martella, Vito; Elia, Gabriella; Desario, Costantina; Campolo, Marco; Buonavoglia, Domenico; Bellacicco, Anna Lucia; Tempesta, Maria; Buonavoglia, Canio

2006-12-01

TaqMan-based diagnostic tests have been developed for the identification of canine parvovirus type 2 (CPV-2) strains in the faeces of dogs with diarrhoea, including a minor groove binder (MGB) probe assay for identification of type 2-based vaccines and field strains (types 2a, 2b and 2c). Since type 2b vaccines have been licensed recently in Europe, two novel MGB assays were developed for discrimination between type 2b vaccines and field strains of CPV. Such assays have been found to be highly sensitive, specific and reproducible, allowing for simultaneous detection of type 2b vaccinal and field strains present in the same specimens. These new assays will help resolution of the diagnostic problems related to the detection of a type 2b strain in the faeces of dogs shortly after the administration of a type 2b vaccine.

How direct competition shapes coexistence and vaccine effects in multi-strain pathogen systems.

PubMed

Gjini, Erida; Valente, Carina; Sá-Leão, Raquel; Gomes, M Gabriela M

2016-01-07

We describe an integrated modeling framework for understanding strain coexistence in polymorphic pathogen systems. Previous studies have debated the utility of neutral formulations and focused on cross-immunity between strains as a major stabilizing mechanism. Here we convey that direct competition for colonization mediates stable coexistence only when competitive abilities amongst pathogen clones satisfy certain pairwise asymmetries. We illustrate our ideas with nested SIS models of single and dual colonization, applied to polymorphic pneumococcal bacteria. By fitting the models to cross-sectional prevalence data from Portugal (before and after the introduction of a seven-valent pneumococcal conjugate vaccine), we are able to not only statistically compare neutral and non-neutral epidemiological formulations, but also estimate vaccine efficacy, transmission and competition parameters simultaneously. Our study highlights that the response of polymorphic pathogen populations to interventions holds crucial information about strain interactions, which can be extracted by suitable nested modeling. Copyright © 2015 Elsevier Ltd. All rights reserved.

Bovine herpesvirus-1: Genetic diversity of field strains from cattle with respiratory disease, genital, fetal disease and systemic neonatal disease and their relationship to vaccine strains.

PubMed

Fulton, R W; d'Offay, J M; Dubovi, E J; Eberle, R

2016-09-02

Bovine herpesvirus-1 (BoHV-1) causes disease in cattle with varied clinical forms. In the U.S. there are two BoHV1 subtypes, BoHV-1.1 and BoHV-1.2b. Control programs in North America incorporate modified live (MLV) or killed (KV) viral vaccines. However, BoHV-1 strains continue to be isolated from diseased animals or fetuses after vaccination. It is possible to differentiate BoHV-1 wild-type from MLV vaccine strains by determining their single nucleotide polymorphism (SNP) patterns through either whole-genome sequencing or PCR sequencing of genomic regions containing vaccine-defining SNPs. To determine the BoHV-1 subtype in clinical isolates and their relationship to MLV strains, 8 isolates from varied clinical disease at three different laboratories in the U.S. were sequenced and phylogenetically analyzed. Five samples were isolated within the past 5 years from New York and 3 were archived samples recovered 35 years prior from Oklahoma and Louisiana. Based on phylogenetic analysis, four of the cases appeared to be due to an MLV vaccine: 3 cases of aborted fetuses and one neonate with systemic BoHV-1 disease. One aborted fetus was from a herd with no reported history of MLV vaccination in two years. The remaining four isolates did not group with any MLV vaccines: two were associated with bovine respiratory disease, one with vulvovaginitis, and a fourth was determined to be a BoHV-1.2b respiratory isolate. Recovery of BoHV-1.1 that is very closely related to an MLV vaccine virus from a herd not receiving vaccines in an extended period prior to its isolation suggests that MLV viruses may remain latent or circulate within herds for long periods. Copyright © 2016 Elsevier B.V. All rights reserved.

Phage-Encoded Colanic Acid-Degrading Enzyme Permits Lytic Phage Infection of a Capsule-Forming Resistant Mutant Escherichia coli Strain

PubMed Central

Kim, Min Soo; Kim, Young Deuk; Hong, Sung Sik; Park, Kwangseo; Ko, Kwan Soo

2014-01-01

In this study, we isolated a bacteriophage T7-resistant mutant strain of Escherichia coli (named S3) and then proceeded to characterize it. The mutant bacterial colonies appeared to be mucoid. Microarray analysis revealed that genes related to colanic acid production were upregulated in the mutant. Increases in colanic acid production by the mutant bacteria were observed when l-fucose was measured biochemically, and protective capsule formation was observed under an electron microscope. We found a point mutation in the lon gene promoter in S3, the mutant bacterium. Overproduction of colanic acid was observed in some phage-resistant mutant bacteria after infection with other bacteriophages, T4 and lambda. Colanic acid overproduction was also observed in clinical isolates of E. coli upon phage infection. The overproduction of colanic acid resulted in the inhibition of bacteriophage adsorption to the host. Biofilm formation initially decreased shortly after infection but eventually increased after 48 h of incubation due to the emergence of the mutant bacteria. Bacteriophage PBECO4 was shown to infect the colanic acid-overproducing mutant strains of E. coli. We confirmed that the gene product of open reading frame 547 (ORF547) of PBECO4 harbored colanic acid-degrading enzymatic (CAE) activity. Treatment of the T7-resistant bacteria with both T7 and PBECO4 or its purified enzyme (CAE) led to successful T7 infection. Biofilm formation decreased with the mixed infection, too. This procedure, using a phage cocktail different from those exploiting solely receptor differences, represents a novel strategy for overcoming phage resistance in mutant bacteria. PMID:25416767

Isolation and complementation analysis of 10 methanol oxidation mutant classes and identification of the methanol dehydrogenase structural gene of Methylobacterium sp. strain AM1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nunn, D.N.; Lidstrom, M.E.

A method has been developed for the direct selection of methanol oxidation mutants of the facultative methylotroph Methylobacterium sp. strain AM1 (formerly Pseudomonas sp. strain AM1). Using this direct selection technique, we have isolated mutants of Methylobacterium sp. strain AM1 that are no longer capable of growth on methanol but retain the ability to grow on methylamine. These methanol oxidation (Mox) mutants were complemented with a genomic clone bank of this organism constructed in the broad-host-range cosmid pVK100, and subcloning and Tn5 mutagenesis experiments have assigned the Mox mutants to 10 distinct complementation groups. Using an open reading frame beta-galactosidasemore » fusion vector and antibodies specific for Methylobacterium sp. strain AM1 methanol dehydrogenase, we have identified the methanol dehydrogenase structural gene and determined the direction of transcription. The results suggest that the synthesis and utilization of an active methanol dehydrogenase in this organism requires at least 10 different gene functions.« less

Phylogenetic relationships of the HA and NA genes between vaccine and seasonal influenza A(H3N2) strains in Korea

PubMed Central

Park, Sehee; Bae, Joon-Yong; Yoo, Kirim; Cheong, Hee Jin; Noh, Ji Yun; Hong, Kyung Wook; Lemey, Philippe; Vrancken, Bram; Kim, Juwon; Nam, Misun; Yun, Soo-Hyeon; Cho, Woo In; Song, Joon Young; Kim, Woo Joo; Park, Mee Sook; Song, Jin-Won; Kee, Sun-Ho; Song, Ki-Joon; Park, Man-Seong

2017-01-01

Seasonal influenza is caused by two influenza A subtype (H1N1 and H3N2) and two influenza B lineage (Victoria and Yamagata) viruses. Of these antigenically distinct viruses, the H3N2 virus was consistently detected in substantial proportions in Korea during the 2010/11-2013/14 seasons when compared to the other viruses and appeared responsible for the influenza-like illness rate peak during the first half of the 2011/12 season. To further scrutinize possible causes for this, we investigated the evolutionary and serological relationships between the vaccine and Korean H3N2 strains during the 2011/12 season for the main antigenic determinants of influenza viruses, the hemagglutinin (HA) and neuraminidase (NA) genes. In the 2011/12 season, when the number of H3N2 cases peaked, the majority of the Korean strains did not belong to the HA clade of A/Perth/16/2009 vaccine, and no Korean strains were of this lineage in the NA segment. In a serological assay, post-vaccinated human sera exhibited much reduced hemagglutination inhibition antibody titers against the non-vaccine clade Korean H3N2 strains. Moreover, Korean strains harbored several amino acid differences in the HA antigenic sites and in the NA with respect to vaccine lineages during this season. Of these, the HA antigenic site C residues 45 and 261 and the NA residue 81 appeared to be the signatures of positive selection. In subsequent seasons, when H3N2 cases were lower, the HA and NA genes of vaccine and Korean strains were more phylogenetically related to each other. Combined, our results provide indirect support for using phylogenetic clustering patterns of the HA and possibly also the NA genes in the selection of vaccine viruses and the assessment of vaccine effectiveness. PMID:28257427

Hyperproduction of sebaceous cis-6-hexadecenoic acid by esterase-reduced mutant of Rhodococcus sp. strain.

PubMed

Araki, Hiroyuki; Hagihara, Hiroshi; Takigawa, Hirofumi; Kotani, Nobuharu; Tsujino, Yukiharu; Koike, Kenzo; Kawai, Shuji; Ozaki, Katsuya; Ito, Susumu

2007-10-01

cis-6-Hexadecenoic acid is a major component of human sebaceous lipids that is involved in skin self-sterilization and atopic dermatitis amelioration. It can be prepared by hydrolysis of isopropyl cis-6-hexadecenoate produced by resting cells of Rhodococcus sp. strain KSM-MT66. To devise an economical industrial-scale process for the production of this rare fatty acid, we optimized the conditions for growing rhodococcal cells. Mg(2+) and Fe(2+) ions are essential for the efficient production of isopropyl cis-6-hexadecenoate. To further increase the production of isopropyl cis-6-hexadecenoate, we created a mutant strain (T64) with reduced esterase activity by random mutagenesis using UV irradiation of MT66. Under an optimized condition, the mutant T64 produced more than 60 g l(-1) isopropyl cis-6-hexadecenoate in a 4-d cultivation, corresponding to about 52 g l(-1)cis-6-hexadecenoate.

Evaluation of a thermostable Newcastle disease virus strain TS09-C as an in-ovo vaccine for chickens

USDA-ARS?s Scientific Manuscript database

In-ovo vaccination is an attractive immunization approach for poultry industry. However, most of the Newcastle disease virus (NDV) vaccine strains used after hatch are unsafe, as in-ovo vaccines, due to their high pathogenicity for chicken embryos. In this study, we evaluated the safety and immunoge...

Efficacy of dart or booster vaccination with strain RB51 in protecting bison against experimental Brucella abortus challenge

USDA-ARS?s Scientific Manuscript database

Vaccination is an effective tool for reducing the prevalence of brucellosis in natural hosts. In this study, we characterized the efficacy of the Brucella abortus strain RB51 (RB51) vaccine in bison when delivered by single intramuscular vaccination (Hand RB51), single pneumatic dart delivery (Dart ...

Efficacy, Safety, and Interactions of a Live Infectious Bursal Disease Virus Vaccine for Chickens Based on Strain IBD V877.

PubMed

Geerligs, Harm J; Ons, Ellen; Boelm, Gert Jan; Vancraeynest, Dieter

2015-03-01

Infectious bursal disease (IBD) is a highly contagious disease in young chickens which can result in high morbidity and mortality and also in great economic losses. The main target for the virus is the lymphoid tissue with a special predilection for the bursa of Fabricius. Several vaccines are available to control the disease. Intermediate plus vaccines are used in chickens with high maternal antibody titers which face high infection pressure. An example of an intermediate plus vaccine is a live vaccine based on IBD strain V877. The results of an efficacy study in commercial broilers with different levels of maternally derived antibodies (MDA) showed that the V877-based IBD vaccine can break through maternal antibody titers of higher than 1100 as determined by an IBD ELISA. The safety of the vaccine was demonstrated in a study in which specific-pathogen-free (SPF) chickens were vaccinated with a tenfold dose of the vaccine strain and a tenfold dose of the vaccine strain after five back passages in SPF chickens. The vaccine virus caused lesions, as could be expected for an intermediate plus vaccine, but the scores were not much higher than the maximal scores allowed for mild IBD vaccines in the European Pharmacopoeia, and reversion to virulence was absent. In studies in SPF chickens, there were no negative impacts by the IBD V877 vaccine on the efficacy of a live QX-like IB vaccine and a live Newcastle disease La Sota vaccine in vaccination challenge studies, although the IBD vaccine had a negative effect on the antibody response generated by the QX-like IB vaccine. It is concluded that the IBD V877 vaccine has the capacity to break through high levels of MDA, has a satisfactory safety profile, and interactions with other live vaccines are limited. In order to limit bursal lesions after vaccination it is recommended to confirm the presence of MDA before vaccinating with the V877 vaccine.

Immunogenicity, reactogenicity, and safety of a P1.7b,4 strain-specific serogroup B meningococcal vaccine given to preteens.

PubMed

Hosking, Jamie; Rasanathan, Kumanan; Mow, Florina Chan; Jackson, Catherine; Martin, Diana; O'Hallahan, Jane; Oster, Philipp; Ypma, Ellen; Reid, Stewart; Aaberge, Ingeborg; Crengle, Sue; Stewart, Joanna; Lennon, Diana

2007-11-01

New Zealand (NZ) has experienced a Neisseria meningitidis serogroup B epidemic since 1991. MeNZB, a strain-specific outer membrane vesicle vaccine made using an NZ epidemic strain isolate, NZ98/254 (B:4:P1.7b,4), from two manufacturing sites, the Norwegian Institute of Public Health (NIPH) and Chiron Vaccines (CV; now Novartis), was evaluated for safety, immunogenicity, and reactogenicity in this observer-blind trial with 8- to 12-year-old children. In year 1, cohort A (n = 302) was randomized 4:1 for receipt of NIPH-MeNZB or MenBvac (Norwegian parent vaccine strain 44/76; B:15:P1.7,16). In year 2, cohort B (n = 313) was randomized 4:1 for receipt of CV-MeNZB or NIPH-MeNZB. Participants all received three vaccinations 6 weeks apart. Local and systemic reactions were monitored for 7 days. Seroresponse was defined as a fourfold or greater rise in the serum bactericidal antibody titer from the baseline titer as measured by a serum bactericidal assay. Those with baseline titers of <1:4 required titers of >/=1:8 to serorespond. Intention-to-treat (ITT) and per protocol (PP) analyses are presented. In cohort A, 74% (ITT) and 73% (PP) of NIPH-MeNZB recipients demonstrated seroresponses against NZ98/254 after three doses, versus 32% (ITT and PP) of MenBvac recipients. In cohort B, seroresponses against NZ98/254 after three doses occurred in 79% (ITT and PP) of CV-MeNZB versus 75% (ITT) and 76% (PP) of NIPH-MeNZB recipients. Vaccines were tolerable, with no vaccine-related serious adverse events. In conclusion, the NZ strain meningococcal B vaccine (MeNZB) from either manufacturing site was immunogenic against New Zealand epidemic vaccine strain meningococci with no safety concerns when given in three doses to these 8- to 12-year-old children.

Efficacy of lyophilised C-strain vaccine after oral immunisation of domestic pigs and wild boar against classical swine fever: first results.

PubMed

Faust, A; Lange, E; Kaden, V

2007-11-01

The aim of this study was to evaluate the efficacy of lyophilised C-strain vaccine in domestic pigs and wild boar after oral application. A new spherical bait form (diameter 3 cm) containing lyophilised vaccine virus and the recent vaccine baits were used for animal experiments. Four vaccination groups were established in experiment 1 (group 1: recent liquid bait vaccine; group 2: spherical baits containing one dose of the lyophilised vaccine; groups 3 (domestic pigs) and 4 (wild boar): spherical baits containing two doses of the lyophilised vaccine) and two groups in experiment 2 (group 1: recent liquid bait vaccine; group 2: spherical baits with two doses of the lyophilised vaccine). Challenge was carried out with the highly virulent virus strain "Alfort 187" (using 100 TCID50 in the first and 1.000 TCID50 in the second experiment). Our results showed that the animals vaccinated with lyophilised C-strain vaccine developed high neutralising antibody titres comparable to those obtained after vaccination with the recent bait vaccine. All pigs which picked up the baits remained healthy after challenge. Neither clinical symptoms nor viremia or virus shedding were observed after infection except in one pig (group 2, experiment 2) which had not consumed the vaccine bait. The surviving domestic pigs and wild boar were tested negative for CSFV and viral RNA at the end of the study. This result demonstrates that lyophilised vaccine may become an effective vaccine formulation for oral immunisation of wild boar against CSF in the near future.

A multiplex reverse transcription-nested polymerase chain reaction for detection and differentiation of wild-type and vaccine strains of canine distemper virus

PubMed Central

2010-01-01

A multiplex reverse transcription-nested polymerase chain reaction (RT-nPCR) method was developed for the detection and differentiation of wild-type and vaccine strains of canine distemper virus (CDV). A pair of primers (P1 and P4) specific for CDV corresponding to the highly conserved region of the CDV genome were used as a common primer pair in the first-round PCR of the nested PCR. Primers P2 specific for CDV wild-type strains, were used as the forward primer together with the common reverse primer P4 in the second round of nested PCR. Primers P3, P5 specific for CDV wild-type strain or vaccine strain, were used as the forward primer together with the common reverse primer P4+P6 in the second round of nested PCR. A fragment of 177 bp was amplified from vaccine strain genomic RNA, and a fragment of 247 bp from wild-type strain genomic RNA in the RT-nPCR, and two fragments of 247 bp and 177 bp were amplified from the mixed samples of vaccine and wild-type strains. No amplification was achieved for uninfected cells, or cells infected with Newcastle disease virus (NDV), canine parvovirus (CPV), canine coronavirus (CCV), rabies virus (RV), or canine adenovirus (CAV). The RT-nPCR method was used to detect 30 field samples suspected of canine distemper from Heilongjiang and Jilin Provinces, and 51 samples in Shandong province. As a result of 30 samples, were found to be wild-type-like, and 5 to be vaccine-strain-like. The RT-nPCR method can be used to effectively detect and differentiate wild-type CDV-infected dogs from dogs vaccinated with CDV vaccine, and thus can be used in clinical detection and epidemiological surveillance. PMID:20433759

Modelling Hepatitis B Virus Antiviral Therapy and Drug Resistant Mutant Strains

NASA Astrophysics Data System (ADS)

Bernal, Julie; Dix, Trevor; Allison, Lloyd; Bartholomeusz, Angeline; Yuen, Lilly

Despite the existence of vaccines, the Hepatitis B virus (HBV) is still a serious global health concern. HBV targets liver cells. It has an unusual replication process involving an RNA pre-genome that the reverse transcriptase domain of the viral polymerase protein translates into viral DNA. The reverse transcription process is error prone and together with the high replication rates of the virus, allows the virus to exist as a heterogeneous population of mutants, known as a quasispecies, that can adapt and become resistant to antiviral therapy. This study presents an individual-based model of HBV inside an artificial liver, and associated blood serum, undergoing antiviral therapy. This model aims to provide insights into the evolution of the HBV quasispecies and the individual contribution of HBV mutations in the outcome of therapy.

A live attenuated strain of Yersinia pestis ΔyscB provides protection against bubonic and pneumonic plagues in mouse model.

PubMed

Zhang, Xuecan; Qi, Zhizhen; Du, Zongmin; Bi, Yujing; Zhang, Qingwen; Tan, Yafang; Yang, Huiying; Xin, Youquan; Yang, Ruifu; Wang, Xiaoyi

2013-05-24

To develop a safe and effective live plague vaccine, the ΔyscB mutant was constructed based on Yersinia pestis biovar Microtus strain 201 that is avirulent to humans, but virulent to mice. The virulence, immunogenicity and protective efficacy of the ΔyscB mutant were evaluated in this study. The results showed that the ΔyscB mutant was severely attenuated, elicited a higher F1-specific antibody titer and provided protective efficacy against bubonic and pneumonic plague in mouse model. The ΔyscB mutant could induce the secretion of both Th1-associated cytokines (IFN-γ, IL-2 and TNF-α) and Th2-associated cytokines (IL-4 and IL-10). Taken together, the ΔyscB mutant represented a potential vaccine candidate based on its ability to generate strong humoral and cell-mediated immune responses and to provide good protection against both subcutaneous and intranasal Y. pestis challenge. Copyright © 2013 Elsevier Ltd. All rights reserved.

Anaplasma marginale Yucatan (Mexico) Strain. Assessment of low virulence and potential use as a live vaccine.

PubMed

Rodríguez Camarillo, Sergio D; García Ortiz, Miguel Angel; Rojas Ramírez, Edmundo E; Cantó Alarcón, Germinal J; Preciado de la Torre, Jesús F; Rosario Cruz, Rodrigo; Ramos Aragón, Juan A; Aboytes Torres, Ramón

2008-12-01

Anaplasma marginale Yucatan strain was found to have low virulence in cattle. We studied the virulence of this isolate by experimental inoculation of 113 susceptible cattle at increasing doses, after which only one animal required treatment for clinical disease. Subsequently, 104 cattle received a live vaccine of this strain by inoculation, which induced immunoprotection after heterologous challenged exposure with a different A. marginale isolate. In this study 14% of the immunized cattle required treatment as compared with the control nonimmunized cattle, in which 56% required treatment. The A. marginale vaccine strains used for the immunization studies had MSP1a variable regions that were different from those used for the challenge exposure.

Pigs immunized with Chinese highly pathogenic PRRS virus modified live vaccine are protected from challenge with North American PRRSV strain NADC-20.

PubMed

Galliher-Beckley, Amy; Li, Xiangdong; Bates, John T; Madera, Rachel; Waters, Andrew; Nietfeld, Jerome; Henningson, Jamie; He, Dongsheng; Feng, Wenhai; Chen, Ruiai; Shi, Jishu

2015-07-09

Modified live virus (MLV) vaccines developed to protect against PRRSV circulating in North America (NA) offer limited protection to highly pathogenic (HP) PRRSV strains that are emerging in Asia. MLV vaccines specific to HP-PRRSV strains commercially available in China provide protection to HP-PRRSV; however, the efficacy of these HP-PRRSV vaccines to current circulating NA PRRS viruses has not been reported. The aim of this study is to investigate whether pigs vaccinated with attenuated Chinese HP-PRRSV vaccine (JXA1-R) are protected from infection by NA PRRSV strain NADC-20. We found that pigs vaccinated with JXA1-R were protected from challenges with HV-PRRSV or NADC-20 as shown by fewer days of clinical fever, reduced lung pathology scores, and lower PRRS virus load in the blood. PRRSV-specific antibodies, as measured by IDEXX ELISA, appeared one week after vaccination and virus neutralizing antibodies were detected four weeks post vaccination. Pigs vaccinated with JXA1-R developed broadly neutralizing antibodies with high titers to NADC-20, JXA1-R, and HV-PRRSV. In addition, we also found that IFN-α and IFN-β occurred at higher levels in the lungs of pigs vaccinated with JXA1-R. Taken together, our studies provide the first evidence that JXA1-R can confer protection in pigs against the heterologous NA PRRSV strain NADC-20. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

A consensus-hemagglutinin-based vaccine delivered by an attenuated Salmonella mutant protects chickens against heterologous H7N1 influenza virus.

PubMed

Hyoung, Kim Je; Hajam, Irshad Ahmed; Lee, John Hwa

2017-06-13

H7N3 and H7N7 are highly pathogenic avian influenza (HPAI) viruses and have posed a great threat not only for the poultry industry but for the human health as well. H7N9, a low pathogenic avian influenza (LPAI) virus, is also highly pathogenic to humans, and there is a great concern that these H7 subtypes would acquire the ability to spread efficiently between humans, thereby becoming a pandemic threat. A vaccine candidate covering all the three subtypes must, therefore, be an integral part of any pandemic preparedness plan. To address this need, we constructed a consensus hemagglutinin (HA) sequence of H7N3, H7N7, and H7N9 based on the data available in the NCBI in early 2012-2015. This artificial sequence was then optimized for protein expression before being transformed into an attenuated auxotrophic mutant of Salmonella Typhimurium, JOL1863 strain. Immunizing chickens with JOL1863, delivered intramuscularly, nasally or orally, elicited efficient humoral and cell mediated immune responses, independently of the route of vaccination. Our results also showed that JOL1863 deliver efficient maturation signals to chicken monocyte derived dendritic cells (MoDCs) which were characterized by upregulation of costimulatory molecules and higher cytokine induction. Moreover, immunization with JOL1863 in chickens conferred a significant protection against the heterologous LPAI H7N1 virus challenge as indicated by reduced viral sheddings in the cloacal swabs. We conclude that this vaccine, based on a consensus HA, could induce broader spectrum of protection against divergent H7 influenza viruses and thus warrants further study.

Efficacy of an inactivated bivalent vaccine against the prevalent strains of Newcastle disease and H9N2 avian influenza.

PubMed

Zhao, Jing; Yang, Huiming; Xu, Hongjun; Ma, Zengbin; Zhang, Guozhong

2017-03-16

Newcastle disease (ND) and avian influenza subtype H9N2 (H9N2 AI) are two of the most important diseases of poultry, causing severe economic losses in the global poultry industry. Vaccination is an effective way to prevent and control the spread of ND virus (NDV) and H9N2 AI virus (AIV), but the antigenic differences between the current circulating strains and the vaccine strains might account for recent ND and H9N2 AI outbreaks in vaccinated poultry flocks. We developed an inactivated bivalent H9N2 and NDV vaccine based on the current prevalent strains of H9N2 AIV and NDV in China and evaluated its efficacy in chickens in this study. The results indicated that the inactivated bivalent vaccine could induce a fast antibody response in vaccinated chickens. The hemagglutination inhibition (HI) titer in the sera increased rapidly, and the highest HI titer was observed at 4 weeks post-vaccination (wpv) with a mean titre of 8.6 log 2 for NDV and 9.5 log 2 for H9N2. Up until 15 wpv, HI titers were still detectable at a high level of over 6 log 2 . The immunized chickens showed no signs of disease after challenge at 3 wpv with the prevalent strains of NDV and H9N2 AIV isolated in 2012-2014. Moreover, viral shedding was completely inhibited in vaccinated chickens after challenge with H9N2 AIV and inhibited by at least 90% with NDV compared to the controls at 5dpc. Our findings suggest that the inactivated NDV and H9N2 vaccine induces a fast and strong antibody response in vaccinated chickens and is efficacious in poultry against NDVs and H9N2 AIVs.

Genetic and antigenic relationship of foot-and-mouth disease virus serotype O isolates with the vaccine strain O1/BFS.

PubMed

Xu, Wanhong; Zhang, Zhidong; Nfon, Charles; Yang, Ming

2018-05-15

Foot-and-mouth disease serotype O viruses (FMDV/O) are responsible for the most outbreaks in FMD endemic countries. O1/BFS is one of the recommended FMD/O vaccine strains by World Reference Laboratory for FMD. In the current study, FMDV/O1 BFS vaccine strain and serotype O field isolates (45) were analyzed phylogenetically and antigenically to gain more insight into the genetic and antigenic characteristics of the vaccine strain and field isolates. O1/BFS showed similarity with 89% of the field isolates using a virus neutralization test (VNT). The P1 region encoding the FMDV capsid was sequenced and analysed for 46 strains of FMDV/O. Phylogenetic analysis showed these viruses originated from five continents and covered eight of 11 reported topotypes. Five isolates that demonstrated low antigenic similarities with O1/BFS were analyzed for their antigenic variation at the known neutralizing antigenic sites. Three of the five isolates demonstrated unique amino acid substitutions at various antigenic sites. No unique amino acid substitutions were observed for the other two unmatched isolates. Positively selected residues were identified on the surface of the FMD virus capsid supporting that it is important to continuously monitor field isolates for their antigenic and phenotypic changes. In conclusion, the vaccine strain O1/BFS is likely to confer protection against 89% of the 45 FMDV/O isolates based on VNT. Thus O1/BFS vaccine strain is still suitable for use in global FMD serotype O outbreak control. Combining data from phylogenetic, molecular and antigenic analysis can provide improvements in the process of vaccine selection. Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.

Development of inactivated poliovirus vaccine from Sabin strains: A progress report.

PubMed

Okayasu, Hiromasa; Sein, Carolyn; Hamidi, Ahd; Bakker, Wilfried A M; Sutter, Roland W

2016-11-01

The Global Polio Eradication Initiative (GPEI) has seen significant progress since it began in 1988, largely due to the worldwide use of oral poliovirus vaccine (OPV). In order to achieve polio eradication the global cessation of OPV is necessary because OPV contains live attenuated poliovirus, which in rare circumstances could re-gain wild poliovirus (WPV) characteristics with potential to establish transmission. The GPEI endgame strategy for the period 2013-2018 recommends the globally synchronised sequential cessation of the Sabin strains contained in the OPV, starting with type 2 Sabin. The withdrawal of Sabin type 2 took place in April 2016, with the introduction of at least one dose of inactivated poliovirus vaccine (IPV) as a risk mitigation strategy. The introduction of IPV into 126 countries since 2013 has required a rapid scale-up of IPV production by the two manufacturers supplying the global public sector market. This scale-up has been fraught with challenges, resulting in reductions of 40-50% of initial supply commitments. Consequently, 22 countries will not be supplied until 2018, and another 23 countries will experience serious stock-outs. In the last decade repeated calls-for-action were made to the global community to invigorate their vision and investment in developing "new poliovirus vaccines" including the development of IPV from less-virulent strains, such as Sabin-IPV (S-IPV). The conventional Salk-IPV production is limited to high-income industrialized-country manufacturers due to the containment requirements (i.e., high sanitation, low force-of-poliovirus-infection, and high population immunity). The use of Sabin strains in the production of S-IPV carries a lower biosafety risk, and was determined to be suitable for production in developing countries, expanding the manufacturing base and making IPV more affordable and accessible in the long term. Significant progress in the S-IPV has been made since 2006. S-IPV is now licensed as S-IPV in

The effects of strain heterology on the epidemiology of equine influenza in a vaccinated population.

PubMed Central

Park, A. W.; Wood, J. L. N.; Daly, J. M.; Newton, J. R.; Glass, K.; Henley, W.; Mumford, J. A.; Grenfell, B. T.

2004-01-01

We assess the effects of strain heterology (strains that are immunologically similar but not identical) on equine influenza in a vaccinated population. Using data relating to individual animals, for both homologous and heterologous vaccinees, we estimate distributions for the latent and infectious periods, quantify the risk of becoming infected in terms of the quantity of cross-reactive antibodies to a key surface protein of the virus (haemagglutinin) and estimate the probability of excreting virus (i.e. becoming infectious) given that infection has occurred. The data suggest that the infectious period, the risk of becoming infected (for a given vaccine-induced level of cross-reactive antibodies) and the probability of excreting virus are increased for heterologously vaccinated animals when compared with homologously vaccinated animals. The data are used to parameterize a modified susceptible, exposed, infectious and recovered/resistant (SEIR) model, which shows that these relatively small differences combine to have a large effect at the population level, where populations of heterologous vaccinees face a significantly increased risk of an epidemic occurring. PMID:15306299

[History of development of the live poliomyelitis vaccine from Sabin attenuated strains in 1959 and idea of poliomyelitis eradication].

PubMed

Lashkevich, V A

2013-01-01

In 1958 Poliomyelitis Institute in Moscow and Institute of Experimental Medicine in St. Petersburg received from A. Sabin the attenuated strains of poliomyelitis virus. The characteristics of the strains were thoroughly studied by A. A. Smorodintsev and coworkers. They found that the virulence of the strains fluctuated slightly in 10 consecutive passages through the intestine of the non-immune children. A part of the Sabin material was used by A. A. Smorodintsev and M. P. Chumakov in the beginning of 1959 for immunizing approximately 40000 children in Estonia, Lithuania, and Latvia. Epidemic poliomyelitis rate in these republics decreased from approximately 1000 cases yearly before vaccination to less than 20 in the third quarter of 1959. This was a convincing proof of the efficacy and safety of the vaccine from the attenuated Sabin strains. In 1959, according to A. Sabin's recommendation, a technology of live vaccine production was developed at the Poliomyelitis Institute, and several experimental lots of vaccine were prepared. In the second part of 1959, 13.5 million children in USSR were immunized. The epidemic poliomyelitis rate decreased 3-5 times in different regions without paralytic cases, which could be attributed to the vaccination. These results were the final proof of high efficiency and safety of live poliomyelitis vaccine from the attenuated Sabin strains. Based on these results, A. Sabin and M. P. Chumakov suggested in 1960 the idea of poliomyelitis eradication using mass immunization of children with live vaccine. 72 million persons up to 20 years old were vaccinated in USSR in 1960 with a 5 times drop in the paralytic rate. 50-year-long use of live vaccine results in poliomyelitis eradication in almost all countries worldwide. More than 10 million children were rescued from the death and palsy. Poliomyelitis eradication in a few countries where it still exists depends not on medical services but is defined by the attitude of their leaders to fight

A Mutant Strain of a Surfactant-Producing Bacterium with Increased Emulsification Activity

NASA Astrophysics Data System (ADS)

Liu, Qingmei; Yao, Jianming; Pan, Renrui; Yu, Zengliang

2005-06-01

As reported in this paper, a strain of oil-degrading bacterium Sp-5-3 was determined to belong to Enterobacteriaceae, which would be useful for microbial enhanced oil recovery (MEOR). The aim of our study was to generate a mutant using low energy N+ beam implantation. With 10 keV of energy and 5.2 × 1014 N+/cm2 of dose - the optimum condition, a mutant, S-34, was obtained, which had nearly a 5-fold higher surface and a 13-fold higher of emulsification activity than the wild type. The surface activity was measured by two methods, namely, a surface tension measuring instrument and a recording of the repulsive circle of the oil film; the emulsification activity was scaled through measuring the separating time of the oil-fermentation mixture. The metabolic acid was determined as methane by means of gas chromatography.

Utility of a stressed-SNP real-time PCR assay for the rapid identification of measles vaccine strain in patient samples.

PubMed

Tran, Thomas; Kostecki, Renata; Catton, Michael; Druce, Julian

2018-05-09

Rapid differentiation of wild-type measles virus from measles vaccine strains is crucial during a measles outbreak and in a measles elimination setting. A real-time RT-PCR for the rapid detection of measles vaccine strains was developed with high specificity and greater sensitivity than when compared to traditional measles genotyping methods. The "stressed" minor grove binder TaqMan probe design approach achieves specificity to vaccine strains only, without compromising sensitivity. This assay has proven to be extremely useful in outbreak settings, without requiring sequence genotyping, for over 4 years at the Regional Measles Reference Laboratory for the Western Pacific Region. Copyright © 2018 Tran et al.

Construction and Characterization of a Nonproliferative El Tor Cholera Vaccine Candidate Derived from Strain 638

PubMed Central

Valle, Edgar; Ledón, Talena; Cedré, Bárbara; Campos, Javier; Valmaseda, Tania; Rodríguez, Boris; García, Luis; Marrero, Karen; Benítez, Jorge; Rodríguez, Sandra; Fando, Rafael

2000-01-01

In recent clinical assays, our cholera vaccine candidate strain, Vibrio cholerae 638 El Tor Ogawa, was well tolerated and immunogenic in Cuban volunteers. In this work we describe the construction of 638T, a thymidine auxotrophic version of improved environmental biosafety. In so doing, the thyA gene from V. cholerae was cloned, sequenced, mutated in vitro, and used to replace the wild-type allele. Except for its dependence on thymidine for growth in minimal medium, 638T is essentially indistinguishable from 638 in the rate of growth and morphology in complete medium. The two strains showed equivalent phenotypes with regard to motility, expression of the celA marker, colonization capacity in the infant mouse cholera model, and immunogenicity in the adult rabbit cholera model. However, the ability of this new strain to survive environmental starvation was limited with respect to that of 638. Taken together, these results suggest that this live, attenuated, but nonproliferative strain is a new, promising cholera vaccine candidate. PMID:11035753

The Vaccine Candidate Vibrio cholerae 638 Is Protective against Cholera in Healthy Volunteers

PubMed Central

García, Luis; Jidy, Manuel Díaz; García, Hilda; Rodríguez, Boris L.; Fernández, Roberto; Año, Gemma; Cedré, Bárbara; Valmaseda, Tania; Suzarte, Edith; Ramírez, Margarita; Pino, Yadira; Campos, Javier; Menéndez, Jorge; Valera, Rodrigo; González, Daniel; González, Irma; Pérez, Oliver; Serrano, Teresita; Lastre, Miriam; Miralles, Fernando; del Campo, Judith; Maestre, Jorge Luis; Pérez, José Luis; Talavera, Arturo; Pérez, Antonio; Marrero, Karen; Ledón, Talena; Fando, Rafael

2005-01-01

Vibrio cholerae 638 is a living candidate cholera vaccine strain attenuated by deletion of the CTXΦ prophage from C7258 (O1, El Tor Ogawa) and by insertion of the Clostridium thermocellum endoglucanase A gene into the hemagglutinin/protease coding sequence. This vaccine candidate was previously found to be well tolerated and immunogenic in volunteers. This article reports a randomized, double-blind, placebo-controlled trial conducted to test short-term protection conferred by 638 against subsequent V. cholerae infection and disease in volunteers in Cuba. A total of 45 subjects were enrolled and assigned to receive vaccine or placebo. The vaccine contained 109 CFU of freshly harvested 638 buffered with 1.3% NaHCO3, while the placebo was buffer alone. After vaccine but not after placebo intake, 96% of volunteers had at least a fourfold increase in vibriocidal antibody titers, and 50% showed a doubling of at least the lipopolysaccharide-specific immunoglobulin A titers in serum. At 1 month after vaccination, five volunteers from the vaccine group and five from the placebo group underwent an exploratory challenge study with 109 CFU of ΔCTXΦ attenuated mutant strain V. cholerae 81. Only two volunteers from the vaccine group shed strain 81 in their feces, but none of them experienced diarrhea; in the placebo group, all volunteers excreted the challenge strain, and three had reactogenic diarrhea. An additional 12 vaccinees and 9 placebo recipients underwent challenge with 7 × 105 CFU of virulent strain V. cholerae 3008 freshly harvested from a brain heart infusion agar plate and buffered with 1.3% NaHCO3. Three volunteers (25%) from the vaccine group and all from the placebo group shed the challenge agent in their feces. None of the 12 vaccinees but 7 volunteers from the placebo group had diarrhea, and 2 of the latter exhibited severe cholera (>5,000 g of diarrheal stool). These results indicate that at 1 month after ingestion of a single oral dose (109 CFU) of strain

The vaccine candidate Vibrio cholerae 638 is protective against cholera in healthy volunteers.

PubMed

García, Luis; Jidy, Manuel Díaz; García, Hilda; Rodríguez, Boris L; Fernández, Roberto; Año, Gemma; Cedré, Bárbara; Valmaseda, Tania; Suzarte, Edith; Ramírez, Margarita; Pino, Yadira; Campos, Javier; Menéndez, Jorge; Valera, Rodrigo; González, Daniel; González, Irma; Pérez, Oliver; Serrano, Teresita; Lastre, Miriam; Miralles, Fernando; Del Campo, Judith; Maestre, Jorge Luis; Pérez, José Luis; Talavera, Arturo; Pérez, Antonio; Marrero, Karen; Ledón, Talena; Fando, Rafael

2005-05-01

Vibrio cholerae 638 is a living candidate cholera vaccine strain attenuated by deletion of the CTXPhi prophage from C7258 (O1, El Tor Ogawa) and by insertion of the Clostridium thermocellum endoglucanase A gene into the hemagglutinin/protease coding sequence. This vaccine candidate was previously found to be well tolerated and immunogenic in volunteers. This article reports a randomized, double-blind, placebo-controlled trial conducted to test short-term protection conferred by 638 against subsequent V. cholerae infection and disease in volunteers in Cuba. A total of 45 subjects were enrolled and assigned to receive vaccine or placebo. The vaccine contained 10(9) CFU of freshly harvested 638 buffered with 1.3% NaHCO(3), while the placebo was buffer alone. After vaccine but not after placebo intake, 96% of volunteers had at least a fourfold increase in vibriocidal antibody titers, and 50% showed a doubling of at least the lipopolysaccharide-specific immunoglobulin A titers in serum. At 1 month after vaccination, five volunteers from the vaccine group and five from the placebo group underwent an exploratory challenge study with 10(9) CFU of DeltaCTXPhi attenuated mutant strain V. cholerae 81. Only two volunteers from the vaccine group shed strain 81 in their feces, but none of them experienced diarrhea; in the placebo group, all volunteers excreted the challenge strain, and three had reactogenic diarrhea. An additional 12 vaccinees and 9 placebo recipients underwent challenge with 7 x 10(5) CFU of virulent strain V. cholerae 3008 freshly harvested from a brain heart infusion agar plate and buffered with 1.3% NaHCO(3). Three volunteers (25%) from the vaccine group and all from the placebo group shed the challenge agent in their feces. None of the 12 vaccinees but 7 volunteers from the placebo group had diarrhea, and 2 of the latter exhibited severe cholera (>5,000 g of diarrheal stool). These results indicate that at 1 month after ingestion of a single oral dose (10

Antigen sparing with adjuvanted inactivated polio vaccine based on Sabin strains

PubMed Central

Westdijk, Janny; Koedam, Patrick; Barro, Mario; Steil, Benjamin P.; Collin, Nicolas; Vedvick, Thomas S.; Bakker, Wilfried A.M.; van der Ley, Peter; Kersten, Gideon

2013-01-01

Six different adjuvants, each in combination with inactivated polio vaccine (IPV) produced with attenuated Sabin strains (sIPV), were evaluated for their ability to enhance virus neutralizing antibody titers (VNTs) in the rat potency model. The increase of VNTs was on average 3-, 15-, 24-fold with adjuvants after one immunization (serotype 1, 2, and 3, respectively). Also after a boost immunization the VNTs of adjuvanted sIPV were on average another 7- 20- 27 times higher than after two inoculations of sIPV without adjuvant. The results indicate that it is feasible to increase the potency of inactivated polio vaccines by using adjuvants. PMID:23313617

Different levels of immunogenicity of two strains of Fowlpox virus as recombinant vaccine vectors eliciting T-cell responses in heterologous prime-boost vaccination strategies.

PubMed

Cottingham, Matthew G; van Maurik, Andre; Zago, Manola; Newton, Angela T; Anderson, Richard J; Howard, M Keith; Schneider, Jörg; Skinner, Michael A

2006-07-01

The FP9 strain of F has been described as a more immunogenic recombinant vaccine vector than the Webster FPV-M (FPW) strain (R. J. Anderson et al., J. Immunol. 172:3094-3100, 2004). This study expands the comparison to include two separate recombinant antigens and multiple, rather than single, independent viral clones derived from the two strains. Dual-poxvirus heterologous prime-boost vaccination regimens using individual clones of recombinant FP9 or FPW in combination with recombinant modified V Ankara expressing the same antigen were evaluated for their ability to elicit T-cell responses against recombinant antigens from Plasmodium berghei (circumsporozoite protein) or human immunodeficiency virus type 1 (a Gag-Pol-Nef fusion protein). Gamma interferon enzyme-linked immunospot assay and fluorescence-activated cell sorting assays of the responses to specific epitopes confirmed the approximately twofold-greater cellular immunogenicity of FP9 compared to FPW, when given as the priming or boosting immunization. Equality of transgene expression in mouse cells infected with the two strains in vitro was verified by Western blotting. Directed partial sequence analysis and PCR analysis of FPW and comparison to available whole-genome sequences revealed that many loci that are mutated in the highly attenuated and culture-adapted FP9 strain are wild type in FPW, including the seven multikilobase deletions. These "passage-specific" alterations are hypothesized to be involved in determining the immunogenicity of fowlpox virus as a recombinant vaccine vector.

Molecular typing of canine parvovirus strains circulating from 2008 to 2012 in an organized kennel in India reveals the possibility of vaccination failure.

PubMed

Mittal, Mitesh; Chakravarti, Soumendu; Mohapatra, J K; Chug, P K; Dubey, Rahul; Upmanuyu, Vikramaditya; Narwal, P S; Kumar, Anil; Churamani, C P; Kanwar, N S

2014-04-01

Canine parvovirus-2 (CPV-2), which emerged in 1978, is considered as the major viral enteric pathogen of the canine population. With the emergence of new antigenic variants and incidences of vaccine failure, CPV has become one of the dreaded diseases of the canines worldwide. The present study was undertaken in an organized kennel from North India to ascertain the molecular basis of the CPV outbreaks in the vaccinated dogs. 415 samples were collected over a 5year period (2008-2012). The outbreak of the disease was more severe in 2012 with high incidence of mortality in pups with pronounced clinical symptoms. Molecular typing based on the VP2 gene was carried out with the 11 isolates from different years and compared with the CPV prototype and the vaccine strains. All the isolates in the study were either new CPV-2a (2012 isolates) or new CPV-2b (2008 and 2011 isolates). There were amino acid mutations at the Tyr324Ile and at the Thr440Ala position in five isolates from 2012 indicating new CPV mutants spreading in India. The CPV vaccines used in the present study failed to generate protective antibody titer against heterogeneous CPV antigenic types. The findings were confirmed when the affected pups were treated with hyper-immune heterogeneous purified immunoglobulin's against CPV in dogs of different antigenic types. Copyright © 2014 Elsevier B.V. All rights reserved.

An interferon inducing porcine reproductive and respiratory syndrome virus vaccine candidate elicits protection against challenge with the heterologous virulent type 2 strain VR-2385 in pigs.

PubMed

Fontanella, Eve; Ma, Zexu; Zhang, Yanjin; de Castro, Alessandra M M G; Shen, Huigang; Halbur, Patrick G; Opriessnig, Tanja

2017-01-03

Achieving consistent protection by vaccinating pigs against porcine reproductive and respiratory syndrome virus (PRRSV) remains difficult. Recently, an interferon-inducing PRRSV vaccine candidate strain A2MC2 was demonstrated to be attenuated and induced neutralizing antibodies. The objective of this study was to determine the efficacy of passage 90 of A2MC2 (A2P90) to protect pigs against challenge with moderately virulent PRRSV strain VR-2385 (92.3% nucleic acid identity with A2MC2) and highly virulent atypical PRRSV MN184 (84.5% nucleic acid identity with A2MC2). Forty 3-week old pigs were randomly assigned to five groups including a NEG-CONTROL group (non-vaccinated, non-challenged), VAC-VR2385 (vaccinated, challenged with strain VR-2385), VR2385 (challenged with strain VR-2385), VAC-MN184 (vaccinated, challenged with strain MN184) and a MN184 group (challenged with MN184 virus). Vaccination was done at 3weeks of age followed by challenge at 8weeks of age. No viremia was detectable in any of the vaccinated pigs; however, by the time of challenge, 15/16 vaccinated pigs had seroconverted based on ELISA and had neutralizing antibodies against a homologous strain with titers ranging from 8 to 128. Infection with VR-2385 resulted in mild-to-moderate clinical disease and lesions. For VR-2385 infected pigs, vaccination significantly lowered PRRSV viremia and nasal shedding by 9days post challenge (dpc), significantly reduced macroscopic lung lesions, and significantly increased the average daily weight gain compared to the non-vaccinated pigs. Infection with MN184 resulted in moderate-to-severe clinical disease and lesions regardless of vaccination status; however, vaccinated pigs had significantly less nasal shedding by dpc 5 compared to non-vaccinated pigs. Under the study conditions, the A2P90 vaccine strain was attenuated without detectable shedding, improved weight gain, and offered protection to the pigs challenged with VR-2385 by reduction of virus load and

Prediction of dynamic behavior of mutant strains from limited wild-type data.

PubMed

Song, Hyun-Seob; Ramkrishna, Doraiswami

2012-03-01

Metabolic engineering is the field of introducing genetic changes in organisms so as to modify their function towards synthesizing new products of high impact to society. However, engineered cells frequently have impaired growth rates thus seriously limiting the rate at which such products are made. The problem is attributable to inadequate understanding of how a metabolic network functions in a dynamic sense. Predictions of mutant strain behavior in the past have been based on steady state theories such as flux balance analysis (FBA), minimization of metabolic adjustment (MOMA), and regulatory on/off minimization (ROOM). Such predictions are restricted to product yields and cannot address productivity, which is of focal interest to applications. We demonstrate that our framework ( [Song and Ramkrishna, 2010] and [Song and Ramkrishna, 2011]), based on a “cybernetic” view of metabolic systems, makes predictions of the dynamic behavior of mutant strains of Escherichia coli from a limited amount of data obtained from the wild-type. Dynamic frameworks must necessarily address the issue of metabolic regulation, which the cybernetic approach does by postulating that metabolism is an optimal dynamic response of the organism to the environment in driving reactions towards ensuring survival. The predictions made in this paper are without parallel in the literature and lay the foundation for rational metabolic engineering. Copyright © 2012 Elsevier Inc. All rights reserved.

A novel rapid direct haemagglutination-inhibition assay for measurements of humoral immune response against non-haemagglutinating Fowlpox virus strains in vaccinated chickens.

PubMed

Wambura, Philemon N; Mzula, Alexanda

2017-10-01

Fowlpox (FP) is a serious disease in chickens caused by Fowlpox virus (FPV). One method currently used to control FPV is vaccination followed by confirmation that antibody titres are protective using the indirect haemagglutination assay (IHA). The direct haemagglutination inhibition (HI) assay is not done because most FPV strains do not agglutinate chicken red blood cells (RBCs). A novel FPV strain TPV-1 which agglutinates chicken RBCs was discovered recently and enabled a direct HI assay to be conducted using homologous sera. This study is therefore aimed at assessing the direct HI assay using a recently discovered novel haemagglutinating FPV strain TPV-1 in chickens vaccinated with a commercial vaccine containing a non-haemagglutinating FPV.Chicks vaccinated with FPV at 1 day-old had antibody geometric mean titres (GMT) of log 2 3.7 at 7 days after vaccination and log 2 8.0 at 28 days after vaccination when tested in the direct HI. Chickens vaccinated at 6 weeks-old had antibody geometric mean titres (GMT) of log 2 5.0 at 7 days after vaccination and log 2 8.4 at 28 days after vaccination when tested in the direct HI. The GMT recorded 28 days after vaccination was slightly higher in chickens vaccinated at 6-week-old than in chicks vaccinated at one-day-old. However, this difference was not significant (P > 0.05). All vaccinated chickens showed "takes". No antibody response to FPV and "takes" were detected in unvaccinated chickens (GMT < 1). There was a slightly higher GMT in chickens of all ages throughout the observation period when the standard assay, the passive (indirect) haemagglutination was used (Overall GMT reached log 2 9.3 ±.0.3 on day 28). However, the difference between the two assays was not significant (P > 0.05). These findings indicate that a simple and rapid direct HI assay using the FPV TPV-1 strain as antigen may be used to measure antibody levels in chickens vaccinated with non-haemagglutinating strains of FPV, and that the titres are

aroA-Deficient Salmonella enterica Serovar Typhimurium Is More Than a Metabolically Attenuated Mutant

PubMed Central

Frahm, Michael; Kocijancic, Dino; Rohde, Manfred; Eckweiler, Denitsa; Bielecka, Agata; Bueno, Emilio; Cava, Felipe; Abraham, Wolf-Rainer; Curtiss, Roy; Häussler, Susanne; Erhardt, Marc; Weiss, Siegfried

2016-01-01

ABSTRACT Recombinant attenuated Salmonella enterica serovar Typhimurium strains are believed to act as powerful live vaccine carriers that are able to elicit protection against various pathogens. Auxotrophic mutations, such as a deletion of aroA, are commonly introduced into such bacteria for attenuation without incapacitating immunostimulation. In this study, we describe the surprising finding that deletion of aroA dramatically increased the virulence of attenuated Salmonella in mouse models. Mutant bacteria lacking aroA elicited increased levels of the proinflammatory cytokine tumor necrosis factor alpha (TNF-α) after systemic application. A detailed genetic and phenotypic characterization in combination with transcriptomic and metabolic profiling demonstrated that ΔaroA mutants display pleiotropic alterations in cellular physiology and lipid and amino acid metabolism, as well as increased sensitivity to penicillin, complement, and phagocytic uptake. In concert with other immunomodulating mutations, deletion of aroA affected flagellin phase variation and gene expression of the virulence-associated genes arnT and ansB. Finally, ΔaroA strains displayed significantly improved tumor therapeutic activity. These results highlight the importance of a functional shikimate pathway to control homeostatic bacterial physiology. They further highlight the great potential of ΔaroA-attenuated Salmonella for the development of vaccines and cancer therapies with important implications for host-pathogen interactions and translational medicine. PMID:27601574

Clinical development of a novel inactivated poliomyelitis vaccine based on attenuated Sabin poliovirus strains.

PubMed

Verdijk, Pauline; Rots, Nynke Y; Bakker, Wilfried A M

2011-05-01

Following achievement of polio eradication, the routine use of all live-attenuated oral poliovirus vaccines should be discontinued. However, the costs per vaccine dose for the alternative inactivated poliovirus vaccine (IPV) are significantly higher and the current production capacity is not sufficient for worldwide distribution of the vaccine. In order to achieve cost-prize reduction and improve affordability, IPV production processes and dose-sparing strategies should be developed to facilitate local manufacture at a relatively lower cost. The use of attenuated Sabin instead of wild-type polio strains will provide additional safety during vaccine production and permits production in low-cost settings. Sabin-IPV is under development by several manufacturers. This article gives an overview of results from clinical trials with Sabin-IPV and discusses the requirements and challenges in the clinical development of this novel IPV.

Fulminant encephalitis associated with a vaccine strain of rubella virus.

PubMed

Gualberto, Felipe Augusto Souza; de Oliveira, Maria Isabel; Alves, Venancio A F; Kanamura, Cristina T; Rosemberg, Sérgio; Sato, Helena Keico; Arantes, Benedito A F; Curti, Suely Pires; Figueiredo, Cristina Adelaide

2013-12-01

Involvement of the central nervous system is common in measles, but rare in rubella. However, rubella virus (RV) can cause a variety of central nervous system syndromes, including meningitis, encephalitis, Guillain-Barré syndrome and sub acute sclerosing panencephalitis. We report the occurrence of one fatal case of the encephalitis associated with measles-rubella (MR) vaccine during an immunization campaign in São Paulo, Brazil. A 31 year-old-man, previously in good health, was admitted at emergency room, with confusion, agitation, inability to stand and hold his head up. Ten days prior to admission, he was vaccinated with combined MR vaccine (Serum Institute of India) and three days later he developed 'flu-like' illness with fever, myalgia and headache. Results of clinical and laboratory exams were consistent with a pattern of viral encephalitis. During hospitalization, his condition deteriorated rapidly with tetraplegia and progression to coma. On the 3rd day of hospitalization he died. Histopathology confirmed encephalitis and immunohistochemistry was positive for RV on brain tissue. RV was also detected by qPCR and virus isolation in cerebrospinal fluid, brain and other clinical samples. The sequence obtained from the isolated virus was identical to that of the RA 27/3 vaccine strain. Copyright © 2013 Elsevier B.V. All rights reserved.

[Beta-lactamase synthesis and excretion in a non-leaky wild strain and a leaky mutant of Escherichia coli K-12].

PubMed

Fognini-Lefebvre, N; Portalier, R

1983-01-17

After transformation of Escherichia coli strains with plasmid pBR 322 and growth in rich L medium, the total amount of beta-lactamase produced, strongly decreased when the temperature was raised from 30 to 42 degrees C, but increased after addition of ampicillin or tetracycline to the medium. beta-lactamase was synthesized and exported into the periplasmic space of wild-type strain, but was not significantly released into the extracellular medium, after growth at low temperature. We have identified an E. coli mutant which excreted up to 90% of total amount of beta-lactamase activity, any temperature. This mutant has been used as an indicator strain, for the development of an in situ test allowing the detection of beta-lactamase excretion.

Large scale parallel pyrosequencing technology: PRRSV strain VR-2332 nsp2 deletion mutant stability in swine

USDA-ARS?s Scientific Manuscript database

Genomes from fifteen porcine reproductive and respiratory syndrome virus (PRRSV) isolates were derived simultaneously using 454 pyrosequencing technology. The viral isolates sequenced were from a recent swine study, in which engineered Type 2 prototype PRRSV strain VR-2332 mutants, with 87, 184, 200...

Characterization of Chicken Splenic-Derived Dendritic Cells Following Vaccine and Very Virulent Strains of Infectious Bursal Disease Virus Infection.

PubMed

Yasmin, A R; Yeap, S K; Hair-Bejo, M; Omar, A R

2016-12-01

Studies have shown that infectious bursal disease virus (IBDV) infects lymphoid cells, mainly B cells and macrophages. This study was aimed to examine the involvement of chicken splenic-derived dendritic cells (ch-sDCs) in specific-pathogen-free chickens following inoculation with IBDV vaccine strain (D78) and a very virulent (vv) strain (UPM0081). Following IBDV infection, enriched activated ch-sDCs were collected by using the negative selection method and were examined based on morphology and immunophenotyping to confirm the isolation method for dendritic cells (DCs). The presence of IBDV on enriched activated ch-sDCs was analyzed based on the immunofluorescence antibody test (IFAT), flow cytometry, and quantitative real-time PCR (RT-qPCR) while the mRNAs of several cytokines were detected using RT-qPCR. The isolated ch-sDCs resembled typical DC morphologies found in mammals by having a veiled shape and they grew in clusters. Meanwhile, the expression of DC maturation markers, namely CD86 and MHCII, were increased at day 2 and day 3 following vvIBDV and vaccine strain inoculation, respectively, ranging from 10% to 40% compared to the control at 2.55% (P < 0.05). At day 3 postinfection, IBDV VP3 proteins colocalized with CD86 were readily detected via IFAT and flow cytometry in both vaccine and vvIBDV strains. In addition, enriched activated ch-sDCs were also detected as positive based on the VP4 gene by RT-qPCR; however, a higher viral load was detected on vvIBDV compared to the vaccine group. Infection with vaccine and vvIBDV strains induced the enriched activated ch-sDCs to produce proinflammatory cytokines and Th1-like cytokines from day 3 onward; however, the expressions were higher in the vvIBDV group (P < 0.05). These data collectively suggest that enriched activated ch-sDCs were permissive to IBDV infection and produced a strong inflammatory and Th1-like cytokine response following vvIBDV infection as compared to the vaccine strain.

A Vero-cell-adapted vaccine donor strain of influenza A virus generated by serial passages.

PubMed

Hu, Weibin; Zhang, Hong; Han, Qinglin; Li, Li; Chen, Yixin; Xia, Ningshao; Chen, Ze; Shu, Yuelong; Xu, Ke; Sun, Bing

2015-01-03

A cell culture-based vaccine production system is preferred for the large-scale production of influenza vaccines and has advantages for generating vaccines against highly pathogenic influenza A viruses. Vero cells have been widely used in human vaccine manufacturing, and the safety of these cells has been well demonstrated. However, the most commonly used influenza-vaccine donor virus, A/Puerto Rico/8/1934 (PR8) virus, does not grow efficiently in Vero cells. Therefore, we adapted the PR8 virus to Vero cells by continuous passaging, and a high-growth strain was obtained after 20 passages. Sequence analysis and virological assays of the adapted strain revealed that mutations in four viral internal genes (NP, PB1, PA and NS1) were sufficient for adaptation. The recombinant virus harboring these mutations (PR8-4mut) displayed accelerated viral transport into the nucleus and increased RNP activity. Importantly, the PR8-4mut could serve as a backbone donor virus to support the growth of the H7N1, H9N2 and H5N1 avian viruses and the H1N1 and H3N2 human viruses in Vero cells without changing its pathogenicity in either chicken embryos or mice. Thus, our work describes the generation of a Vero-adapted, high-yield PR8-4mut virus that may serve as a promising candidate for an influenza-vaccine donor virus. Copyright © 2014 Elsevier Ltd. All rights reserved.

Methods of producing protoporphyrin IX and bacterial mutants therefor

DOEpatents

Zhou, Jizhong; Qiu, Dongru; He, Zhili; Xie, Ming

2016-03-01

The presently disclosed inventive concepts are directed in certain embodiments to a method of producing protoporphyrin IX by (1) cultivating a strain of Shewanella bacteria in a culture medium under conditions suitable for growth thereof, and (2) recovering the protoporphyrin IX from the culture medium. The strain of Shewanella bacteria comprises at least one mutant hemH gene which is incapable of normal expression, thereby causing an accumulation of protoporphyrin IX. In certain embodiments of the method, the strain of Shewanella bacteria is a strain of S. loihica, and more specifically may be S. loihica PV-4. In certain embodiments, the mutant hemH gene of the strain of Shewanella bacteria may be a mutant of shew_2229 and/or of shew_1140. In other embodiments, the presently disclosed inventive concepts are directed to mutant strains of Shewanella bacteria having at least one mutant hemH gene which is incapable of normal expression, thereby causing an accumulation of protoporphyrin IX during cultivation of the bacteria. In certain embodiments the strain of Shewanella bacteria is a strain of S. loihica, and more specifically may be S. loihica PV-4. In certain embodiments, the mutant hemH gene of the strain of Shewanella bacteria may be a mutant of shew_2229 and/or shew_1140.

Immunogenicity, Reactogenicity, and Safety of a P1.7b,4 Strain-Specific Serogroup B Meningococcal Vaccine Given to Preteens▿

PubMed Central

Hosking, Jamie; Rasanathan, Kumanan; Mow, Florina Chan; Jackson, Catherine; Martin, Diana; O'Hallahan, Jane; Oster, Philipp; Ypma, Ellen; Reid, Stewart; Aaberge, Ingeborg; Crengle, Sue; Stewart, Joanna; Lennon, Diana

2007-01-01

New Zealand (NZ) has experienced a Neisseria meningitidis serogroup B epidemic since 1991. MeNZB, a strain-specific outer membrane vesicle vaccine made using an NZ epidemic strain isolate, NZ98/254 (B:4:P1.7b,4), from two manufacturing sites, the Norwegian Institute of Public Health (NIPH) and Chiron Vaccines (CV; now Novartis), was evaluated for safety, immunogenicity, and reactogenicity in this observer-blind trial with 8- to 12-year-old children. In year 1, cohort A (n = 302) was randomized 4:1 for receipt of NIPH-MeNZB or MenBvac (Norwegian parent vaccine strain 44/76; B:15:P1.7,16). In year 2, cohort B (n = 313) was randomized 4:1 for receipt of CV-MeNZB or NIPH-MeNZB. Participants all received three vaccinations 6 weeks apart. Local and systemic reactions were monitored for 7 days. Seroresponse was defined as a fourfold or greater rise in the serum bactericidal antibody titer from the baseline titer as measured by a serum bactericidal assay. Those with baseline titers of <1:4 required titers of ≥1:8 to serorespond. Intention-to-treat (ITT) and per protocol (PP) analyses are presented. In cohort A, 74% (ITT) and 73% (PP) of NIPH-MeNZB recipients demonstrated seroresponses against NZ98/254 after three doses, versus 32% (ITT and PP) of MenBvac recipients. In cohort B, seroresponses against NZ98/254 after three doses occurred in 79% (ITT and PP) of CV-MeNZB versus 75% (ITT) and 76% (PP) of NIPH-MeNZB recipients. Vaccines were tolerable, with no vaccine-related serious adverse events. In conclusion, the NZ strain meningococcal B vaccine (MeNZB) from either manufacturing site was immunogenic against New Zealand epidemic vaccine strain meningococci with no safety concerns when given in three doses to these 8- to 12-year-old children. PMID:17898183

Efficacy of a trivalent influenza vaccine against seasonal strains and against 2009 pandemic H1N1: A randomized, placebo-controlled trial.

PubMed

Mcbride, William J H; Abhayaratna, Walter P; Barr, Ian; Booy, Robert; Carapetis, Jonathan; Carson, Simon; De Looze, Ferdinandus; Ellis-Pegler, Rod; Heron, Leon; Karrasch, Jeff; Marshall, Helen; Mcvernon, Jodie; Nolan, Terry; Rawlinson, William; Reid, Jim; Richmond, Peter; Shakib, Sepehr; Basser, Russell L; Hartel, Gunter F; Lai, Michael H; Rockman, Steven; Greenberg, Michael E

2016-09-22

Before pandemic H1N1 vaccines were available, the potential benefit of existing seasonal trivalent inactivated influenza vaccines (IIV3s) against influenza due to the 2009 pandemic H1N1 influenza strain was investigated, with conflicting results. This study assessed the efficacy of seasonal IIV3s against influenza due to 2008 and 2009 seasonal influenza strains and against the 2009 pandemic H1N1 strain. This observer-blind, randomized, placebo-controlled study enrolled adults aged 18-64years during 2008 and 2009 in Australia and New Zealand. Participants were randomized 2:1 to receive IIV3 or placebo. The primary objective was to demonstrate the efficacy of IIV3 against laboratory-confirmed influenza. Participants reporting an influenza-like illness during the period from 14days after vaccination until 30 November of each study year were tested for influenza by real-time reverse transcription polymerase chain reaction. Over a study period of 2years, 15,044 participants were enrolled (mean age±standard deviation: 35.5±14.7years; 54.4% female). Vaccine efficacy of the 2008 and 2009 IIV3s against influenza due to any strain was 42% (95% confidence interval [CI]: 30%, 52%), whereas vaccine efficacy against influenza due to the vaccine-matched strains was 60% (95% CI: 44%, 72%). Vaccine efficacy of the 2009 IIV3 against influenza due to the 2009 pandemic H1N1 strain was 38% (95% CI: 19%, 53%). No vaccine-related deaths or serious adverse events were reported. Solicited local and systemic adverse events were more frequent in IIV3 recipients than placebo recipients (local: IIV3 74.6% vs placebo 20.4%, p<0.001; systemic: IIV3 46.6% vs placebo 39.1%, p<0.001). The 2008 and 2009 IIV3s were efficacious against influenza due to seasonal influenza strains and the 2009 IIV3 demonstrated moderate efficacy against influenza due to the 2009 pandemic H1N1 strain. Funded by CSL Limited, ClinicalTrials.gov identifier NCT00562484. Copyright © 2016 The Authors. Published by Elsevier

Egg-Independent Influenza Vaccines and Vaccine Candidates

PubMed Central

Manini, Ilaria; Pozzi, Teresa; Rossi, Stefania; Montomoli, Emanuele

2017-01-01

Vaccination remains the principal way to control seasonal infections and is the most effective method of reducing influenza-associated morbidity and mortality. Since the 1940s, the main method of producing influenza vaccines has been an egg-based production process. However, in the event of a pandemic, this method has a significant limitation, as the time lag from strain isolation to final dose formulation and validation is six months. Indeed, production in eggs is a relatively slow process and production yields are both unpredictable and highly variable from strain to strain. In particular, if the next influenza pandemic were to arise from an avian influenza virus, and thus reduce the egg-laying hen population, there would be a shortage of embryonated eggs available for vaccine manufacturing. Although the production of egg-derived vaccines will continue, new technological developments have generated a cell-culture-based influenza vaccine and other more recent platforms, such as synthetic influenza vaccines. PMID:28718786

Vaccination with Recombinant Cryptococcus Proteins in Glucan Particles Protects Mice against Cryptococcosis in a Manner Dependent upon Mouse Strain and Cryptococcal Species.

PubMed

Specht, Charles A; Lee, Chrono K; Huang, Haibin; Hester, Maureen M; Liu, Jianhua; Luckie, Bridget A; Torres Santana, Melanie A; Mirza, Zeynep; Khoshkenar, Payam; Abraham, Ambily; Shen, Zu T; Lodge, Jennifer K; Akalin, Ali; Homan, Jane; Ostroff, Gary R; Levitz, Stuart M

2017-11-28

Development of a vaccine to protect against cryptococcosis is a priority given the enormous global burden of disease in at-risk individuals. Using glucan particles (GPs) as a delivery system, we previously demonstrated that mice vaccinated with crude Cryptococcus -derived alkaline extracts were protected against lethal challenge with Cryptococcus neoformans and Cryptococcus gattii The goal of the present study was to identify protective protein antigens that could be used in a subunit vaccine. Using biased and unbiased approaches, six candidate antigens (Cda1, Cda2, Cda3, Fpd1, MP88, and Sod1) were selected, recombinantly expressed in Escherichia coli , purified, and loaded into GPs. Three mouse strains (C57BL/6, BALB/c, and DR4) were then vaccinated with the antigen-laden GPs, following which they received a pulmonary challenge with virulent C. neoformans and C. gattii strains. Four candidate vaccines (GP-Cda1, GP-Cda2, GP-Cda3, and GP-Sod1) afforded a significant survival advantage in at least one mouse model; some vaccine combinations provided added protection over that seen with either antigen alone. Vaccine-mediated protection against C. neoformans did not necessarily predict protection against C. gattii Vaccinated mice developed pulmonary inflammatory responses that effectively contained the infection; many surviving mice developed sterilizing immunity. Predicted T helper cell epitopes differed between mouse strains and in the degree to which they matched epitopes predicted in humans. Thus, we have discovered cryptococcal proteins that make promising candidate vaccine antigens. Protection varied depending on the mouse strain and cryptococcal species, suggesting that a successful human subunit vaccine will need to contain multiple antigens, including ones that are species specific. IMPORTANCE The encapsulated fungi Cryptococcus neoformans and Cryptococcus gattii are responsible for nearly 200,000 deaths annually, mostly in immunocompromised individuals. An

[Construction and pathogenic identification of aes-31 gene mutant of avian pathogenic Escherichia coli strain E058].

PubMed

Huan, Haixia; Zhang, Ke; Chen, Xiang; Gao, Song; Liu, Xiufan

2010-12-01

To find the primary function of aes-31 fragment through construction of defined mutation of Avian Pathogenic Escherichia coli strain E058 and animal experiments. The fragment of aes-31 was generated by PCR and cloned into pGEM-T-easy vector. A resultant suicide vector containing the aes-31 fragment named pMEG375-aes-31 was constructed and transformed to a receptor strain SM10. Then recombinant strain SM10 was hybridized with E058 strain in solid state. Mutant derivatives of strain E058 were generated by homologous recombination and were named E058 (delta aes-31). The 50% lethal dose (LD50) of E058 and E058 (delta aes-31) in commercial day-old chickens experimentally inoculated via intratrachea were 10(4.3) CFU and 10(3.5) CFU, respectively. The same way was used to inoculate with 10(8) CFU to obtain the pathogenic ability of E058 and E058 (delta aes-31) in 35-days-old SPF chickens. In the chicken challenge model,the mutant was tested to determine the individual function for virulence and persistence in 2-week-old SPF chicks. The pathogenicity test for E058 strain and E058 (delta aes-31) strain showed that the mutant had a higher mortality (75%) to 35-day-old specific pathogen-free (SPF) chicks than that of E058 (62.5%). In the chicken challenge model,there was no obviously CFUs difference in blood and lung in chicks of E058 group and E058 (delta aes-31) group 6 hours after inoculation. After 24 hours there was obvious CFUs difference in heart, liver, spleen, lung and blood in chicks of E058 group and E058 (delta aes-31) group. After 48 hours, there was also obvious CFUs difference in heart, liver and spleen in chicks of E058 group and E058 (delta aes-31) group E058 (delta aes-31) had a trend of increasing virulence in chicks. Aes-31 might be associated with negative regulatory gene for E058 virulence and its actual function needed further study.

A genome-scale Escherichia coli kinetic metabolic model k-ecoli457 satisfying flux data for multiple mutant strains

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khodayari, Ali; Maranas, Costas D.

Kinetic models of metabolism at a genome scale that faithfully recapitulate the effect of multiple genetic interventions would be transformative in our ability to reliably design novel overproducing microbial strains. Here, we introduce k-ecoli457, a genome-scale kinetic model of Escherichia coli metabolism that satisfies fluxomic data for wild-type and 25 mutant strains under different substrates and growth conditions. The k-ecoli457 model contains 457 model reactions, 337 metabolites and 295 substrate-level regulatory interactions. Parameterization is carried out using a genetic algorithm by simultaneously imposing all available fluxomic data (about 30 measured fluxes per mutant). Furthermore, the Pearson correlation coefficient between experimentalmore » data and predicted product yields for 320 engineered strains spanning 24 product metabolites is 0.84. This is substantially higher than that using flux balance analysis, minimization of metabolic adjustment or maximization of product yield exhibiting systematic errors with correlation coefficients of, respectively, 0.18, 0.37 and 0.47.« less

A genome-scale Escherichia coli kinetic metabolic model k-ecoli457 satisfying flux data for multiple mutant strains

DOE PAGES

Khodayari, Ali; Maranas, Costas D.

2016-12-20

Kinetic models of metabolism at a genome scale that faithfully recapitulate the effect of multiple genetic interventions would be transformative in our ability to reliably design novel overproducing microbial strains. Here, we introduce k-ecoli457, a genome-scale kinetic model of Escherichia coli metabolism that satisfies fluxomic data for wild-type and 25 mutant strains under different substrates and growth conditions. The k-ecoli457 model contains 457 model reactions, 337 metabolites and 295 substrate-level regulatory interactions. Parameterization is carried out using a genetic algorithm by simultaneously imposing all available fluxomic data (about 30 measured fluxes per mutant). Furthermore, the Pearson correlation coefficient between experimentalmore » data and predicted product yields for 320 engineered strains spanning 24 product metabolites is 0.84. This is substantially higher than that using flux balance analysis, minimization of metabolic adjustment or maximization of product yield exhibiting systematic errors with correlation coefficients of, respectively, 0.18, 0.37 and 0.47.« less

Antigen sparing with adjuvanted inactivated polio vaccine based on Sabin strains.

PubMed

Westdijk, Janny; Koedam, Patrick; Barro, Mario; Steil, Benjamin P; Collin, Nicolas; Vedvick, Thomas S; Bakker, Wilfried A M; van der Ley, Peter; Kersten, Gideon

2013-02-18

Six different adjuvants, each in combination with inactivated polio vaccine (IPV) produced with attenuated Sabin strains (sIPV), were evaluated for their ability to enhance virus neutralizing antibody titres (VNTs) in the rat potency model. The increase of VNTs was on average 3-, 15-, 24-fold with adjuvants after one immunization (serotypes 1, 2, and 3, respectively). Also after a boost immunization the VNTs of adjuvanted sIPV were on average another 7-20-27 times higher than after two inoculations of sIPV without adjuvant. The results indicate that it is feasible to increase the potency of inactivated polio vaccines by using adjuvants. Copyright © 2013 Elsevier Ltd. All rights reserved.

Immunogenicity and safety of a quadrivalent inactivated influenza vaccine compared with two trivalent inactivated influenza vaccines containing alternate B strains in adults: A phase 3, randomized noninferiority study.

PubMed

Treanor, John T; Albano, Frank R; Sawlwin, Daphne C; Graves Jones, Alison; Airey, Jolanta; Formica, Neil; Matassa, Vince; Leong, Jane

2017-04-04

Vaccination is the most effective means of influenza prevention. Efficacy of trivalent vaccines may be enhanced by including both B strain lineages. This phase 3, double-blind study assessed the immunogenicity and safety/tolerability of a quadrivalent inactivated influenza vaccine (IIV4) versus the United States (US)-licensed 2014-2015 trivalent inactivated influenza vaccine (IIV3-Yamagata [IIV3-YAM]; Afluria) and IIV3 containing the alternate Victoria B strain (IIV3-VIC) in adults ≥18years. Participants (n=3484) were randomized 2:1:1 and stratified by age to receive IIV4 (n=1741), IIV3-YAM (n=871), or IIV3-VIC (n=872). The primary objective was to demonstrate noninferiority of the immunological response to IIV4 versus IIV3-YAM and IIV3-VIC. Noninferiority was assessed by hemagglutination inhibition geometric mean titer (GMT) ratio (IIV3/IIV4; upper bound of two-sided 95% confidence interval [CI]≤1.5) and seroconversion rate (SCR) difference (IIV3 - IIV4; upper bound of two-sided 95% CI≤10%) for vaccine strains. Solicited local and systemic adverse events (AEs) were assessed for 7days postvaccination, AEs recorded for 28days postvaccination, and serious AEs for 6months postvaccination. IIV4 elicited a noninferior immune response for matched strains, and superior response for unmatched B strains not contained in IIV3 comparators. Adjusted GMT ratios (95% CI) for A/H1N1, A/H3N2, B/YAM, and B/VIC strains were 0.93 (0.88, 0.99), 0.93 (0.88, 0.98), 0.87 (IIV3-YAM; 0.82, 0.93), and 0.95 (IIV3-VIC; 0.88, 1.03), respectively. Corresponding values for SCR differences (95% CI) were -1.1 (-4.5, 2.3), -1.7 (-5.0, 1.7), -3.2 (IIV3-YAM; -7.4, 0.9), and -1.6 (IIV3-VIC; -5.8, 2.5). AEs were generally mild and experienced by 52.9% of participants. Serious AEs were reported with a slightly higher frequency with IIV4 (2.3%) versus IIV3-YAM (1.6%) and IIV3-VIC (1.5%). IIV4 demonstrated immunological noninferiority to the US-licensed IIV3, and superiority for unmatched B strains

Serological profile of buffalo (Bubalus bubalis) female calves vaccinated with standard Brucella abortus strain 19 vaccine using rose bengal, 2-mercaptoethanol and complement fixation tests.

PubMed

Nardi, G Júnior; Ribeiro, M G; Jorge, A M; Megid, J; Silva, L M P

2012-03-01

The serological profiles of 21 female buffaloes vaccinated between 3 and 8 months of age using Brucella abortus strain 19 (S19) were evaluated by rose bengal (RBT), 2-mercaptoethanol (2ME) and complement fixation (CFT) tests. The serum strains were collected in day zero, 15, 30, 45, 60th days and subsequently to each 30 months, until 720th day after vaccination. No animal showed reaction in day zero. In 15th day above 95% of animals revealed reaction in all tests. All the animals presented absence of reactions in CFT, RBT and 2ME tests at 270, 300 and 360 days after vaccination, respectively. Our finding highlighted early response in CFT compared than other conventional agglutination tests. None of animals presented oscillation of titers or reactions in any test after 360 day of study, which enables the use of these tests after this period without interference of antibodies from S19 vaccine origin between 3 and 8 months in buffalo heifers. Copyright © 2011 The International Alliance for Biological Standardization. Published by Elsevier Ltd. All rights reserved.

Unique Safety Issues Associated with Virus Vectored Vaccines: Potential for and Theoretical Consequences of Recombination with Wild Type Virus Strains

PubMed Central

Condit, Richard C.; Williamson, Anna-Lise; Sheets, Rebecca; Seligman, Stephen J.; Monath, Thomas P.; Excler, Jean-Louis; Gurwith, Marc; Bok, Karin; Robertson, James S.; Kim, Denny; Hendry, Michael; Singh, Vidisha; Mac, Lisa M.; Chen, Robert T.

2016-01-01

In 2003 and 2013, the World Health Organization convened informal consultations on characterization and quality aspects of vaccines based on live virus vectors. In the resulting reports, one of several issues raised for future study was the potential for recombination of virus-vectored vaccines with wild type pathogenic virus strains. This paper presents an assessment of this issue formulated by the Brighton Collaboration. To provide an appropriate context for understanding the potential for recombination of virus-vectored vaccines, we review briefly the current status of virus vectored vaccines, mechanisms of recombination between viruses, experience with recombination involving live attenuated vaccines in the field, and concerns raised previously in the literature regarding recombination of virus-vectored vaccines with wild type virus strains. We then present a discussion of the major variables that could influence recombination between a virus-vectored vaccine and circulating wild type virus and the consequences of such recombination, including intrinsic recombination properties of the parent virus used as a vector; sequence relatedness of vector and wild virus; virus host range, pathogenesis and transmission; replication competency of vector in target host; mechanism of vector attenuation; additional factors potentially affecting virulence; and circulation of multiple recombinant vectors in the same target population. Finally, we present some guiding principles for vector design and testing intended to anticipate and mitigate the potential for and consequences of recombination of virus-vectored vaccines with wild type pathogenic virus strains. PMID:27346303

One-step multiplex real-time RT-PCR assay for detecting and genotyping wild-type group A rotavirus strains and vaccine strains (Rotarix® and RotaTeq®) in stool samples.

PubMed

Gautam, Rashi; Mijatovic-Rustempasic, Slavica; Esona, Mathew D; Tam, Ka Ian; Quaye, Osbourne; Bowen, Michael D

2016-01-01

Background. Group A rotavirus (RVA) infection is the major cause of acute gastroenteritis (AGE) in young children worldwide. Introduction of two live-attenuated rotavirus vaccines, RotaTeq® and Rotarix®, has dramatically reduced RVA associated AGE and mortality in developed as well as in many developing countries. High-throughput methods are needed to genotype rotavirus wild-type strains and to identify vaccine strains in stool samples. Quantitative RT-PCR assays (qRT-PCR) offer several advantages including increased sensitivity, higher throughput, and faster turnaround time. Methods. In this study, a one-step multiplex qRT-PCR assay was developed to detect and genotype wild-type strains and vaccine (Rotarix® and RotaTeq®) rotavirus strains along with an internal processing control (Xeno or MS2 RNA). Real-time RT-PCR assays were designed for VP7 (G1, G2, G3, G4, G9, G12) and VP4 (P[4], P[6] and P[8]) genotypes. The multiplex qRT-PCR assay also included previously published NSP3 qRT-PCR for rotavirus detection and Rotarix® NSP2 and RotaTeq® VP6 qRT-PCRs for detection of Rotarix® and RotaTeq® vaccine strains respectively. The multiplex qRT-PCR assay was validated using 853 sequence confirmed stool samples and 24 lab cultured strains of different rotavirus genotypes. By using thermostable rTth polymerase enzyme, dsRNA denaturation, reverse transcription (RT) and amplification (PCR) steps were performed in single tube by uninterrupted thermocycling profile to reduce chances of sample cross contamination and for rapid generation of results. For quantification, standard curves were generated using dsRNA transcripts derived from RVA gene segments. Results. The VP7 qRT-PCRs exhibited 98.8-100% sensitivity, 99.7-100% specificity, 85-95% efficiency and a limit of detection of 4-60 copies per singleplex reaction. The VP7 qRT-PCRs exhibited 81-92% efficiency and limit of detection of 150-600 copies in multiplex reactions. The VP4 qRT-PCRs exhibited 98

One-step multiplex real-time RT-PCR assay for detecting and genotyping wild-type group A rotavirus strains and vaccine strains (Rotarix® and RotaTeq®) in stool samples

PubMed Central

Mijatovic-Rustempasic, Slavica; Esona, Mathew D.; Tam, Ka Ian; Quaye, Osbourne; Bowen, Michael D.

2016-01-01

Background. Group A rotavirus (RVA) infection is the major cause of acute gastroenteritis (AGE) in young children worldwide. Introduction of two live-attenuated rotavirus vaccines, RotaTeq® and Rotarix®, has dramatically reduced RVA associated AGE and mortality in developed as well as in many developing countries. High-throughput methods are needed to genotype rotavirus wild-type strains and to identify vaccine strains in stool samples. Quantitative RT-PCR assays (qRT-PCR) offer several advantages including increased sensitivity, higher throughput, and faster turnaround time. Methods. In this study, a one-step multiplex qRT-PCR assay was developed to detect and genotype wild-type strains and vaccine (Rotarix® and RotaTeq®) rotavirus strains along with an internal processing control (Xeno or MS2 RNA). Real-time RT-PCR assays were designed for VP7 (G1, G2, G3, G4, G9, G12) and VP4 (P[4], P[6] and P[8]) genotypes. The multiplex qRT-PCR assay also included previously published NSP3 qRT-PCR for rotavirus detection and Rotarix® NSP2 and RotaTeq® VP6 qRT-PCRs for detection of Rotarix® and RotaTeq® vaccine strains respectively. The multiplex qRT-PCR assay was validated using 853 sequence confirmed stool samples and 24 lab cultured strains of different rotavirus genotypes. By using thermostable rTth polymerase enzyme, dsRNA denaturation, reverse transcription (RT) and amplification (PCR) steps were performed in single tube by uninterrupted thermocycling profile to reduce chances of sample cross contamination and for rapid generation of results. For quantification, standard curves were generated using dsRNA transcripts derived from RVA gene segments. Results. The VP7 qRT-PCRs exhibited 98.8–100% sensitivity, 99.7–100% specificity, 85–95% efficiency and a limit of detection of 4–60 copies per singleplex reaction. The VP7 qRT-PCRs exhibited 81–92% efficiency and limit of detection of 150–600 copies in multiplex reactions. The VP4 qRT-PCRs exhibited 98.8�

No demonstrable association between the Leningrad-Zagreb mumps vaccine strain and aseptic meningitis in a large clinical trial in Egypt.

PubMed

Sharma, H J; Oun, S Aly; Bakr, S S Abou; Kapre, S V; Jadhav, S S; Dhere, R M; Bhardwaj, S

2010-04-01

To address the claim that the Leningrad-Zagreb (L-Z) mumps vaccine strain is causally associated with aseptic meningitis, a prospective, post-marketing safety study was conducted with a measles-mumps-rubella vaccine (MMR) (TRESIVAC(R); Serum Institute of India Ltd., Pune, India), which uses the L-Z strain as its mumps component in Egypt. In all, 453 119 children (65 423 children aged 16-24 months and 329 211 children aged 5-7 years) received MMR. The control groups which, as a result of local health regulations, were slightly younger than vaccinees, comprised 12 253 and 46 232 children, respectively. Using questionnaires, the parents recorded solicited local, systemic and neurological adverse events for up to 42 days post-vaccination. All data were analysed externally on an intention-to-treat basis by individuals not participating in the study. Local and/or systemic reactions were reported in a small percentage of participants, with pain, fever and parotitis being the most common signs among vaccinees in both age groups. No case of aseptic meningitis, encephalitis, anaphylaxis or convulsions was observed in any participant. Thus, in this series of more than 450 000 Egyptian children, the L-Z mumps vaccine strain in this vaccine did not cause aseptic meningitis. The vaccine is considerably cheaper than Western competitors and a valid alternative to other MMR vaccines.

Binding of purified and radioiodinated capsular polysaccharides from Cryptococcus neoformans serotype A strains to capsule-free mutants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Small, J.M.; Mitchell, T.G.

Strains 6, 15, 98, 110, and 145 of Cryptococcus neoformans serotype A vary in capsule size, animal virulence, and susceptibility to in vitro phagocytosis. The isolated capsular polysaccharides (CPSs) differ in monosaccharide composition ratios and molecular size, as determined by gel filtration. The purpose of this investigation was to characterize the binding of CPSs to capsule-free mutants of C. neoformans and to examine CPSs from these strains for differences in their ability to bind, to determine whether such differences might explain the variation in the pathobiology of these strains. CPSs were partially periodate oxidized, tyraminated, iodinated with /sup 125/I, andmore » used in binding studies with two capsule-free mutants of C. neoformans, strain 602 and Cap59. Binding was specific for yeast species and for polysaccharide and was saturable, which is consistent with a receptor-mediated mechanism of attachment. Binding occurred rapidly and was only slowly reversible. Binding was also independent of pH from pH 5.5 to 8, of cation concentrations, and of competition by sugars up to 1.0 M concentrations. Only a portion of CPS was capable of binding, and strains varied in the extent to which their CPS bound. CPS-15-IV (peak IV was the major polysaccharide peak on DEAE-cellulose chromatography of CPS from strain 15) had the highest proportion of binding (40%), followed by CPS from strains 98, 6, 145, 110, and 15-III (peak III was an earlier eluting fraction of CPS from strain 15). The CPSs differed similarly in their ability to competitively inhibit binding. Treatment of CPS, but not yeast cells, with proteinase XIV abolished binding without altering the CPS gross structure. Treatment of yeast cells with proteases, heat, or formaldehyde did not alter binding, and both strain 602 and Cap59 bound CPS similarly. Binding to encapsulated yeast cells was minimal.« less

Binding of purified and radioiodinated capsular polysaccharides from Cryptococcus neoformans serotype A strains to capsule-free mutants.

PubMed Central

Small, J M; Mitchell, T G

1986-01-01

Strains 6, 15, 98, 110, and 145 of Cryptococcus neoformans serotype A vary in capsule size, animal virulence, and susceptibility to in vitro phagocytosis. The isolated capsular polysaccharides (CPSs) differ in monosaccharide composition ratios and molecular size, as determined by gel filtration. The purpose of this investigation was to characterize the binding of CPSs to capsule-free mutants of C. neoformans and to examine CPSs from these strains for differences in their ability to bind, to determine whether such differences might explain the variation in the pathobiology of these strains. CPSs were partially periodate oxidized, tyraminated, iodinated with 125I, and used in binding studies with two capsule-free mutants of C. neoformans, strain 602 and Cap59. Binding was specific for yeast species and for polysaccharide and was saturable, which is consistent with a receptor-mediated mechanism of attachment. Binding occurred rapidly and was only slowly reversible. Binding was also independent of pH from pH 5.5 to 8, of cation concentrations, and of competition by sugars up to 1.0 M concentrations. Only a portion of CPS was capable of binding, and strains varied in the extent to which their CPS bound. CPS-15-IV (peak IV was the major polysaccharide peak on DEAE-cellulose chromatography of CPS from strain 15) had the highest proportion of binding (40%), followed by CPS from strains 98, 6, 145, 110, and 15-III (peak III was an earlier eluting fraction of CPS from strain 15). The CPSs differed similarly in their ability to competitively inhibit binding. Treatment of CPS, but not yeast cells, with proteinase XIV abolished binding without altering the CPS gross structure. Treatment of yeast cells with proteases, heat, or formaldehyde did not alter binding, and both strain 602 and Cap59 bound CPS similarly. Binding to encapsulated yeast cells was minimal. PMID:3536747