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Sample records for mutant vaccine strain

  1. Draft Genome Sequence of the Intermediate Rough Vaccine Strain Brucella abortus S19Δper Mutant

    PubMed Central

    Chaudhuri, Pallab; Goswami T, Tapas K.; Lalsiamthara, Jonathan; Kaur, Gurpreet; Vishnu, Udayakumar S.; Sankarasubramanian, Jagadesan; Gunasekaran, Paramasamy

    2015-01-01

    Here, we report the genome sequence of the intermediate rough vaccine strain mutant, Brucella abortus S19Δper. The length of the draft genome was 3,271,238 bp, with 57.2% G+C content. A total of 3,204 protein-coding genes and 56 RNA genes were predicted. PMID:26564050

  2. Generation and Characterization of an Attenuated Mutant in a Response Regulator Gene of Francisella tularensis Live Vaccine Strain (LVS)

    PubMed Central

    Sammons-Jackson, Wendy L.; McClelland, Karen; Manch-Citron, Jean N.; Metzger, Dennis W.; Bakshi, Chandra Shekhar; Garcia, Emilio; Rasley, Amy

    2008-01-01

    Francisella tularensis is a zoonotic bacterium that must exist in diverse environments ranging from arthropod vectors to mammalian hosts. To better understand how virulence genes are regulated in these different environments, a transcriptional response regulator gene (genome locus FTL0552) was deleted in F. tularensis live vaccine strain (LVS). The FTL0552 deletion mutant exhibited slightly reduced rates of extracellular growth but was unable to replicate or survive in mouse macrophages and was avirulent in the mouse model using either BALB/c or C57BL/6 mice. Mice infected with the FTL0552 mutant produced reduced levels of inflammatory cytokines, exhibited reduced histopathology, and cleared the bacteria quicker than mice infected with LVS. Mice that survived infection with the FTL0552 mutant were afforded partial protection when challenged with a lethal dose of the virulent SchuS4 strain (4 of 10 survivors, day 21 postinfection) when compared to naive mice (0 of 10 survivors by day 7 postinfection). Microarray experiments indicate that 148 genes are regulated by FTL0552. Most of the genes are downregulated, indicating that FTL0552 controls transcription of genes in a positive manner. Genes regulated by FTL0552 include genes located within the Francisella pathogenicity island that are essential for intracellular survival and virulence of F. tularensis. Further, a mutant in FTL0552 or the comparable locus in SchuS4 (FTT1557c) may be an alternative candidate vaccine for tularemia. PMID:18613792

  3. 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

  4. The Brucella abortus Phosphoglycerate Kinase Mutant Is Highly Attenuated and Induces Protection Superior to That of Vaccine Strain 19 in Immunocompromised and Immunocompetent Mice ▿

    PubMed Central

    Trant, Cyntia G. M. C.; Lacerda, Thais L. S.; Carvalho, Natalia B.; Azevedo, Vasco; Rosinha, Gracia M. S.; Salcedo, Suzana P.; Gorvel, Jean-Pierre; Oliveira, Sergio C.

    2010-01-01

    Brucella abortus is a facultative intracellular bacterial pathogen that causes abortion in domestic animals and undulant fever in humans. The mechanism of virulence of Brucella spp. is not yet fully understood. Therefore, it is crucial to identify new molecules that can function as virulence factors to better understand the host-pathogen interplay. Herein, we identified the gene encoding the phosphoglycerate kinase (PGK) of B. abortus strain 2308. To test the role of PGK in Brucella pathogenesis, a pgk deletion mutant was constructed. Replacement of the wild-type pgk by recombination was demonstrated by Southern and Western blot analyses. The B. abortus Δpgk mutant strain exhibited extreme attenuation in bone marrow-derived macrophages and in vivo in BALB/c, C57BL/6, 129/Sv, and interferon regulatory factor-1 knockout (IRF-1 KO) mice. Additionally, at 24 h postinfection the Δpgk mutant was not found within the same endoplasmic reticulum-derived compartment as the wild-type bacteria, but, instead, over 60% of Brucella-containing vacuoles (BCVs) retained the late endosomal/lysosomal marker LAMP1. Furthermore, the B. abortus Δpgk deletion mutant was used as a live vaccine. Challenge experiments revealed that the Δpgk mutant strain induced protective immunity in 129/Sv or IRF-1 KO mice that was superior to the protection conferred by commercial strain 19 or RB51. Finally, the results shown here demonstrated that Brucella PGK is critical for full bacterial virulence and that a Δpgk mutant may serve as a potential vaccine candidate in future studies. PMID:20194591

  5. The Brucella abortus phosphoglycerate kinase mutant is highly attenuated and induces protection superior to that of vaccine strain 19 in immunocompromised and immunocompetent mice.

    PubMed

    Trant, Cyntia G M C; Lacerda, Thais L S; Carvalho, Natalia B; Azevedo, Vasco; Rosinha, Gracia M S; Salcedo, Suzana P; Gorvel, Jean-Pierre; Oliveira, Sergio C

    2010-05-01

    Brucella abortus is a facultative intracellular bacterial pathogen that causes abortion in domestic animals and undulant fever in humans. The mechanism of virulence of Brucella spp. is not yet fully understood. Therefore, it is crucial to identify new molecules that can function as virulence factors to better understand the host-pathogen interplay. Herein, we identified the gene encoding the phosphoglycerate kinase (PGK) of B. abortus strain 2308. To test the role of PGK in Brucella pathogenesis, a pgk deletion mutant was constructed. Replacement of the wild-type pgk by recombination was demonstrated by Southern and Western blot analyses. The B. abortus Delta pgk mutant strain exhibited extreme attenuation in bone marrow-derived macrophages and in vivo in BALB/c, C57BL/6, 129/Sv, and interferon regulatory factor-1 knockout (IRF-1 KO) mice. Additionally, at 24 h postinfection the Delta pgk mutant was not found within the same endoplasmic reticulum-derived compartment as the wild-type bacteria, but, instead, over 60% of Brucella-containing vacuoles (BCVs) retained the late endosomal/lysosomal marker LAMP1. Furthermore, the B. abortus Delta pgk deletion mutant was used as a live vaccine. Challenge experiments revealed that the Delta pgk mutant strain induced protective immunity in 129/Sv or IRF-1 KO mice that was superior to the protection conferred by commercial strain 19 or RB51. Finally, the results shown here demonstrated that Brucella PGK is critical for full bacterial virulence and that a Delta pgk mutant may serve as a potential vaccine candidate in future studies. PMID:20194591

  6. Use of a genetically defined double mutant strain of Bordetella bronchiseptica lacking adenylate cyclase and type III secretion as a live vaccine.

    PubMed

    Mann, Paul; Goebel, Elizabeth; Barbarich, James; Pilione, Mylisa; Kennett, Mary; Harvill, Eric

    2007-07-01

    While most vaccines consisting of killed bacteria induce high serum antibody titers, they do not always confer protection as effective as that induced by infection, particularly against mucosal pathogens. Bordetella bronchiseptica is a gram-negative respiratory pathogen that is endemic in many nonhuman mammalian populations and causes substantial disease in a variety of animals. At least 14 different live attenuated vaccines against this pathogen are available for use in a variety of livestock and companion animals. However, there are few published data on the makeup or efficacy of these vaccines. Here we report the use of a genetically engineered double mutant of B. bronchiseptica, which lacks adenylate cyclase and type III secretion, as a vaccine candidate. This strain is safe at high doses, even for highly immunocompromised animals, and induces immune responses that are protective against highly divergent B. bronchiseptica strains, preventing colonization in the lower respiratory tract and decreasing the bacterial burden in the upper respiratory tract. This novel B. bronchiseptica vaccine candidate induces strong local immunity while eliminating damage caused by the two predominant cytotoxic mechanisms. PMID:17452472

  7. Oral immunization with an attenuated Salmonella Gallinarum mutant as a fowl typhoid vaccine with a live adjuvant strain secreting the B subunit of Escherichia coli heat-labile enterotoxin

    PubMed Central

    2013-01-01

    Background The Salmonella Gallinarum (SG) lon/cpxR deletion mutant JOL916 was developed as a live vaccine candidate for fowl typhoid (FT), and a SG mutant secreting an Escherichia coli heat-labile enterotoxin B subunit (LTB), designated JOL1229, was recently constructed as an adjuvant strain for oral vaccination against FT. In this study, we evaluated the immunogenicity and protective properties of the SG mutant JOL916 and the LTB adjuvant strain JOL1229 in order to establish a prime and boost immunization strategy for each strain. In addition, we compared the increase in body weight, the immunogenicity, the egg production rates, and the bacteriological egg contamination of these strains with those of SG 9R, a widely used commercial vaccine. Results Plasma IgG, intestinal secretory IgA (sIgA), and cell-mediated responses were significantly induced after a boost inoculation with a mixture of JOL916 and JOL1229, and significant reductions in the mortality of chickens challenged with a wild-type SG strain were observed in the immunized groups. There were no significant differences in increases in body weight, cell-mediated immune responses, or systemic IgG responses between our vaccine mixture and the SG 9R vaccine groups. However, there was a significant elevation in intestinal sIgA in chickens immunized with our mixture at 3 weeks post-prime-immunization and at 3 weeks post-boost-immunization, while sIgA levels in SG 9R-immunized chickens were not significantly elevated compared to the control. In addition, the SG strain was not detected in the eggs of chickens immunized with our mixture. Conclusion Our results suggest that immunization with the LTB-adjuvant strain JOL1229 can significantly increase the immune response, and provide efficient protection against FT with no side effects on body weight, egg production, or egg contamination. PMID:23647814

  8. Attenuated Shigella flexneri 2a vaccine strain CVD 1204 expressing colonization factor antigen I and mutant heat-labile enterotoxin of enterotoxigenic Escherichia coli.

    PubMed

    Koprowski, H; Levine, M M; Anderson, R J; Losonsky, G; Pizza, M; Barry, E M

    2000-09-01

    A multivalent live oral vaccine against both Shigella spp. and enterotoxigenic Escherichia coli (ETEC) is being developed based on the hypothesis that protection can be achieved if attenuated shigellae express ETEC fimbrial colonization factors and genetically detoxified heat-labile toxin from a human ETEC isolate (LTh). Two detoxified derivatives of LTh, LThK63 and LThR72, were engineered by substitution-serine to lysine at residue 63, or lysine to arginine at residue 72. The genes encoding these two derivatives were cloned separately on expression plasmids downstream from the CFA/I operon. Following electroporation into S. flexneri 2a vaccine strain CVD 1204, coexpression of CFA/I and LThK63 or LThR72 was demonstrated by Western blot analysis, GM(1) binding assays, and agglutination with anti-CFA/I antiserum. Hemagglutination and electron microscopy confirmed surface expression of CFA/I. Guinea pigs immunized intranasally on days 0 and 15 with CVD 1204 expressing CFA/I and LThK63 or LThR72 exhibited high titers of both serum immunoglobulin G (IgG) and mucosal secretory IgA anti-CFA/I; 40% of the animals produced antibodies directed against LTh. All immunized guinea pigs also produced mucosal IgA (in tears) and serum IgG anti-S. flexneri 2a O antibodies. Furthermore, all immunized animals were protected from challenge with wild-type S. flexneri 2a. This prototype Shigella-ETEC hybrid vaccine demonstrates the feasibility of expressing multiple ETEC antigens on a single plasmid in an attenuated Shigella vaccine strain and engendering immune responses against both the heterologous antigens and vector strain. PMID:10948101

  9. Newly attenuated Mycobacterium bovis mutants as vaccines against bovine tuberculosis, particularly for possums.

    PubMed

    Collins, D M; Buddle, B M; Kawakami, R P; Hotter, G; Mildenhall, N; Mouat, P; Murney, R; Ataera, H; Price-Carter, M; Bruere, P; Wards, B J; de Lisle, G W

    2011-07-01

    Bovine tuberculosis costs New Zealand more than $80 million per year, mostly because extensive areas of the country are occupied by brushtail possums infected with Mycobacterium bovis. AgResearch has a major programme to produce new live tuberculosis vaccines that can be delivered to possums. Primary work involved development of molecular biological methods to enable genetic manipulation of M. bovis, including the production of random and specific mutants. Many avirulent mutants of M. bovis have been produced and their vaccine efficacy has been compared to BCG in guinea pigs. Selected mutants that perform at least as well as BCG are retested in guinea pigs using an extended vaccination protocol in which animals are pre-sensitized to environmental mycobacteria to mimic natural exposure. Ten candidate vaccines that have induced good protection in guinea pigs have been subsequently tested as vaccines in possums. While the protective efficacy of an M. bovis mutant inoculated into guinea pigs reliably indicated that some protection would be induced in possums, the most protective mutant in guinea pigs was different from that in possums. This illustrates the importance of testing in the target species as part of new vaccine development. An important outcome of this work was the identification of an operon in M. bovis whose inactivation produced an avirulent M. bovis vaccine candidate that was better than BCG in protecting possums from experimental tuberculosis. Allelic exchange methods are now being used to produce vaccine strains with multiple specific mutations to improve safety and immunological characteristics. PMID:21420259

  10. Immuogenicity and safety of a natural rough mutant of Brucella suis as a vaccine for swine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of the current study was to evaluate the safety, immunogenicity and clearance of the natural rough mutant of Brucella suis strain 353-1 (353-1) as a vaccine in domestic swine. In three studies encompassing 155 animals, pigs were inoculated with 353-1 by conjunctival (5 x 10**7 CFU), p...

  11. DeltaznuADeltapurE Brucella abortus 2308 mutant as a live vaccine candidate.

    PubMed

    Yang, Xinghong; Thornburg, Theresa; Walters, Nancy; Pascual, David W

    2010-01-22

    To create a new, safe brucellosis live vaccine, a double mutant strain was constructed from Brucella abortus 2308. Using the DeltaznuA B. abortus 2308 mutant, a second mutation was introduced by deleting purE gene. The DeltaznuA DeltapurE B. abortus 2308 strain was less capable of surviving in macrophages. When evaluated in vivo, it was cleared within 8 weeks (wks) from mice, causing significantly less inflammation than spleens obtained from wild-type B. abortus 2308-infected mice. Furthermore, two doses of DeltaznuA DeltapurE B. abortus 2308 conferred 0.79 log protection, similar to S19 as did a single dose of DeltaznuA B. abortus 2308. Thus, this study shows the DeltaznuA DeltapurE B. abortus 2308 strain to be a potential livestock vaccine candidate. PMID:19914192

  12. Live Attenuated Borrelia burgdorferi Targeted Mutants in an Infectious Strain Background Protect Mice from Challenge Infection.

    PubMed

    Hahn, Beth L; Padmore, Lavinia J; Ristow, Laura C; Curtis, Michael W; Coburn, Jenifer

    2016-08-01

    Borrelia burgdorferi, B. garinii, and B. afzelii are all agents of Lyme disease in different geographic locations. If left untreated, Lyme disease can cause significant and long-term morbidity, which may continue after appropriate antibiotic therapy has been administered and live bacteria are no longer detectable. The increasing incidence and geographic spread of Lyme disease are renewing interest in the vaccination of at-risk populations. We took the approach of vaccinating mice with two targeted mutant strains of B. burgdorferi that, unlike the parental strain, are avirulent in mice. Mice vaccinated with both strains were protected against a challenge with the parental strain and a heterologous B. burgdorferi strain by either needle inoculation or tick bite. In ticks, the homologous strain was eliminated but the heterologous strain was not, suggesting that the vaccines generated a response to antigens that are produced by the bacteria both early in mammalian infection and in the tick. Partial protection against B. garinii infection was also conferred. Protection was antibody mediated, and reactivity to a variety of proteins was observed. These experiments suggest that live attenuated B. burgdorferi strains may be informative regarding the identification of protective antigens produced by the bacteria and recognized by the mouse immune system in vivo Further work may illuminate new candidates that are effective and safe for the development of Lyme disease vaccines. PMID:27335385

  13. Conjunctival and intramuscular vaccination of pigs with a live avirulent strain of Salmonella cholerae-suis.

    PubMed

    Kramer, T T; Pardon, P; Marly, J; Bernard, S

    1987-07-01

    An avirulent mutant strain of Salmonella cholerae-suis was cloned for resistance to streptomycin and nalidixic acid. The mutant strain 33-13 also was used because of its avirulence and immunogenicity in mice. Weaned pigs were vaccinated with live strain 33-13; 5 pigs were vaccinated by conjunctivally administered 5.5 X 10(7) organisms (low dose), 5 were conjunctivally administered 5.5 X 10(9) organisms (high dose), and 5 pigs were administered 5.5 X 10(9) organisms (high dose) IM. Transient fever and transient fecal shedding of the vaccine strain developed in pigs vaccinated IM, but not in 2 groups of pigs vaccinated conjunctivally. After intratracheal administration of virulent strain 38-9, nonvaccinated control pigs (n = 9) developed persistent high fever, anorexia, bacteremia, diarrhea, and fecal shedding of strain 38-9, whereas vaccinated pigs remained afebrile and clinically normal. Nonvaccinated and uninfected sentinel pigs (n = 8) were kept in units of 2 pigs with each group of experimental pigs, and remained healthy throughout the experiment. Thirteen vaccinated and 7 nonvaccinated control pigs were killed 42 days after vaccination, and 2 vaccinated, 2 nonvaccinated, and 8 sentinel control pigs were killed 58 days after vaccination. Ten organs were evaluated by quantitative bacteriology on necropsy of all pigs for the presence of vaccine strain 33-13, and for virulent strain 38-9. Strain 33-13 was not found. Lung and liver, lesions were found in most of the nonvaccinated control pigs, with a high frequency of recovery of large numbers of strain 38-9 from the mesenteric lymph nodes, lungs, liver, and ileum.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3631689

  14. Inactivated pep27 mutant as an effective mucosal vaccine against a secondary lethal pneumococcal challenge in mice

    PubMed Central

    Choi, Sang-Yoon; Tran, Thao Dang-Hien; Briles, David E.

    2013-01-01

    Purpose A pep27 mutant may be able to elicit mucosal immunity against pneumococcal diseases, and could be employed as an inexpensive attenuated vaccine. However, this particular mutant contains an erythromycin-resistance marker. The purpose of the current study is to develop a markerless pep27 mutant and assess whether this inactivated mutant is able to induce mucosal immunity. Materials and Methods Mice were vaccinated intranasally with the inactivated markerless pep27 mutant every 2 weeks for a total of three times, after which time serum samples were analyzed for antibody titers. The mice were then challenged with a lethal D39 strain and their survival time was measured. The cross-reactivity of the antisera against pep27 was also compared to other mutant serotypes. Results Intranasal immunization of mice with the inactivated markerless pep27 mutant provides effective protection and rapidly cleared bacterial colonization in vivo. Moreover, antisera raised against the pep27 mutant may cross-react with several other serotype strains. Conclusion Intranasal immunization with the inactivated pep27 mutant may be able to provide mucosal immunity, and could represent an efficient mucosal vaccine. PMID:23596592

  15. Mutant Native Outer Membrane Vesicles Combined with a Serogroup A Polysaccharide Conjugate Vaccine for Prevention of Meningococcal Epidemics in Africa

    PubMed Central

    Pajon, Rolando; Fergus, Andrew M.; Granoff, Dan M.

    2013-01-01

    Background The meningococcal serogroup A (MenA) polysaccharide conjugate vaccine used in Sub-Saharan Africa does not prevent disease caused by MenW or MenX strains, which also cause epidemics in the region. We investigated the vaccine-potential of native outer membrane vesicles with over-expressed factor H-binding protein (NOMV-fHbp), which targeted antigens in African meningococcal strains, and was combined with a MenA polysaccharide conjugate vaccine. Methodology/Principal Findings The NOMV-fHbp vaccine was prepared from a mutant African MenW strain with PorA P1.5,2, attenuated endotoxin (ΔLpxL1), deleted capsular genes, and over-expressed fHbp in variant group 1. The NOMV-fHbp was adsorbed with Al(OH)3 and used to reconstitute a lyophilized MenA conjugate vaccine, which normally is reconstituted with liquid MenC, Y and W conjugates in a meningococcal quadrivalent conjugate vaccine (MCV4-CRM, Novartis). Mice immunized with the NOMV-fHbp vaccine alone developed serum bactericidal (human complement) activity against 13 of 15 African MenA strains tested; 10 of 10 African MenX strains, 7 of 7 African MenW strains, and 6 of 6 genetically diverse MenB strains with fHbp variant group 1 (including 1 strain from The Gambia). The combination NOMV-fHbp/MenA conjugate vaccine elicited high serum bactericidal titers against the two MenA strains tested that were resistant to bactericidal antibodies elicited by the NOMV-fHbp alone; the combination elicited higher titers against the MenA and MenW strains than those elicited by a control MCV4-CRM vaccine (P<0.05); and high titers against MenX and MenB strains. For most strains, the titers elicited by a control NOMV-fHbp knock out vaccine were <1∶10 except when the strain PorA matched the vaccine (titers >1∶000). Conclusion/Significance The NOMV-fHbp/MenA conjugate vaccine provided similar or higher coverage against MenA and MenW strains than a quadrivalent meningococcal conjugate vaccine, and extended protection against Men

  16. Combinatorial Synthetic Peptide Vaccine Strategy Protects against Hypervirulent CovR/S Mutant Streptococci.

    PubMed

    Pandey, Manisha; Mortensen, Rasmus; Calcutt, Ainslie; Powell, Jessica; Batzloff, Michael R; Dietrich, Jes; Good, Michael F

    2016-04-15

    Cluster of virulence responder/sensor (CovR/S) mutant group A streptococci (GAS) are serious human pathogens of multiple M protein strains that upregulate expression of virulence factors, including the IL-8 proteaseStreptococcus pyogenescell envelope proteinase (SpyCEP), thus blunting neutrophil-mediated killing and enabling ingress of bacteria from a superficial wound to deep tissue. We previously showed that a combination vaccine incorporating J8-DT (conserved peptide vaccine from the M protein) and a recombinant SpyCEP fragment protects against CovR/S mutants. To enhance the vaccine's safety profile, we identified a minimal epitope (S2) that was the target for anti-SpyCEP Abs that could protect IL-8 from SpyCEP-mediated proteolysis. Abs from healthy humans and from mice experimentally infected with GAS also recognized S2, albeit at low titers. Native SpyCEP may be poorly immunogenic (cryptic or subdominant), and it would be to the organism's advantage if the host did not induce a strong Ab response against it. However, S2 conjugated to diphtheria toxoid is highly immunogenic and induces Abs that recognize and neutralize SpyCEP. Hence, we describe a two-component peptide vaccine that induces Abs (anti-S2) that protect IL-8 from proteolysis and other Abs (anti-J8) that cause strain-independent killing in the presence of neutrophils. We show that either component alone is ineffectual in preventing skin infection and bacteremia due to CovR/S mutants but that the combination induces complete protection. This protection correlated with a significant influx of neutrophils to the infection site. The data strongly suggest that the lack of natural immunity to hypervirulent GAS strains in humans could be rectified by this combination vaccine. PMID:26969753

  17. Evaluation of Brucella abortus Phosphoglucomutase (pgm) Mutant as a New Live Rough-Phenotype Vaccine

    PubMed Central

    Ugalde, Juan Esteban; Comerci, Diego José; Leguizamón, M. Susana; Ugalde, Rodolfo Augusto

    2003-01-01

    Brucella abortus S19 is the vaccine most frequently used against bovine brucellosis. Although it induces good protection levels, it cannot be administered to pregnant cattle, revaccination is not advised due to interference in the discrimination between infected and vaccinated animals during immune-screening procedures, and the vaccine is virulent for humans. Due to these reasons, there is a continuous search for new bovine vaccine candidates that may confer protection levels comparable to those conferred by S19 but without its disadvantages. A previous study characterized the phenotype associated with the phosphoglucomutase (pgm) gene disruption in Brucella abortus S2308, as well as the possible role for the smooth lipopolysaccharide (LPS) in virulence and intracellular multiplication in HeLa cells (J. E. Ugalde, C. Czibener, M. F. Feldman, and R. A. Ugalde, Infect. Immun. 68:5716-5723, 2000). In this report, we analyze the protection, proliferative response, and cytokine production induced in BALB/c mice by a Δpgm deletion strain. We show that this strain synthesizes O antigen with a size of approximately 45 kDa but is rough. This is due to the fact that the Δpgm strain is unable to assemble the O side chain in the complete LPS. Vaccination with the Δpgm strain induced protection levels comparable to those induced by S19 and generated a proliferative splenocyte response and a cytokine profile typical of a Th1 response. On the other hand, we were unable to detect a specific anti-O-antigen antibody response by using the fluorescence polarization assay. In view of these results, the possibility that the Δpgm mutant could be used as a vaccination strain is discussed. PMID:14573645

  18. Avian pathogenic Escherichia coli ΔtonB mutants are safe and protective live-attenuated vaccine candidates.

    PubMed

    Holden, Karen M; Browning, Glenn F; Noormohammadi, Amir H; Markham, Philip; Marenda, Marc S

    2014-10-10

    Avian pathogenic Escherichia coli (APEC) cause colibacillosis, a serious respiratory disease in poultry. Most APEC strains possess TonB-dependent outer membrane transporters for the siderophores salmochelin and aerobactin, which both contribute to their capacity to cause disease. To assess the potential of iron transport deficient mutants as vaccine candidates, the tonB gene was deleted in the APEC wild type strain E956 and a Δfur (ferric uptake repressor) mutant of E956. The growth of the ΔtonB and ΔtonB/Δfur mutants was impaired in iron-restricted conditions, but not in iron-replete media. Day old chicks were exposed to aerosols of the mutants to assess their efficacy as live attenuated vaccines. At day 18, the birds were challenged with aerosols of the virulent parent strain E956. Both mutants conferred protection against colibacillosis; weight gains and lesion scores were significantly different between the vaccinated groups and an unvaccinated challenged control group. Thus mutation of iron uptake systems can be used as a platform technology to generate protective live attenuated vaccines against extraintestinal E. coli infections, and potentially a range of Gram negative pathogens of importance in veterinary medicine. PMID:25205199

  19. Novel BVDV-2 mutants as new candidates for modified-live vaccines.

    PubMed

    Zemke, Johanna; König, Patricia; Mischkale, Katrin; Reimann, Ilona; Beer, Martin

    2010-04-21

    Protection against Bovine viral diarrhea virus (BVDV) type 2 infection of commercially available vaccines is often limited due to marked genetic and antigenic differences between BVDV types 1 (BVDV-1) and 2 (BVDV-2). Therefore, the immunogenicity of selected BVDV-1 and BVDV-2 mutants derived from infectious full-length cDNA clones and their use as modified-live vaccine candidates against challenge infection with a virulent heterologous BVDV-2 field isolate were investigated. Deletion mutants of BVDV-1 and BVDV-2 lacking a part of the N(pro) gene (BVDV-1DeltaN(pro)/BVDV-2DeltaN(pro)) were used as well as a packaged replicon with a deletion in the structural core protein encoding region (BVDV-2DeltaC-pseudovirions). The 25 calves used in this vaccination/challenge trial were allocated in five groups (n=5/group). One group received BVDV-1DeltaN(pro) (1 shot), one group BVDV-2DeltaN(pro) (1 shot), one group received both, BVDV-1DeltaN(pro) and BVDV-2DeltaN(pro) (1 shot), and one group was immunised with the BVDV-2DeltaC-pseudovirions (2 shots). The fifth group served as non-vaccinated control group. All groups were challenged intranasally with the BVDV-2 strain HI916 and monitored for signs of clinical disease, virus shedding and viremia. All tested BVDV vaccine candidates markedly reduced the outcome of the heterologous virulent BVDV-2 challenge infection showing graduated protective effects. The BVDV-2DeltaN(pro) mutant was able to induce complete protection and a "sterile immunity" upon challenge. Thus it represents a promising candidate for an efficacious future live vaccine. PMID:19875253

  20. Staphylococcus aureus avirulent mutant vaccine induces humoral and cellular immune responses on pregnant heifers.

    PubMed

    Pellegrino, M; Rodriguez, N; Vivas, A; Giraudo, J; Bogni, C

    2016-06-17

    Bovine mastitis produces economic losses, attributable to the decrease in milk production, reduced milk quality, costs of treatment and replacement of animals. A successful prophylactic vaccine against Staphylococcus aureus should elicit both humoral and cellular immune responses. In a previous report we evaluated the effectiveness of a live vaccine to protect heifers against challenge with a virulent strain. In the present study the immunological response of heifers after combined immunization schedule was investigated. In a first experimental trial, heifers were vaccinated with 3 subcutaneous doses of avirulent mutant S. aureus RC122 before calving and one intramammary dose (IMD) after calving. Antibodies concentration in blood, bactericidal effect of serum from vaccinated animals and lymphocyte proliferation was determined. The levels of total IgG, IgG1 and IgG2 in colostrum and the lymphocyte proliferation index were significantly higher in vaccinated respect to non-vaccinated group throughout the experiment. The second trial, where animals were inoculated with different vaccination schedules, was carried out to determine the effect of the IMD on the level of antibodies in blood and milk, cytokines (IL-13 and IFN-γ) concentration and milk's SCC and bacteriology. The bacterial growth of the S. aureus strains was totally inhibited at 1-3×10(6) and 1-3×10(3)cfu/ml, when the strains were mixed with pooled serum diluted 1/40. The results shown that IMD has not a significant effect on the features determinate. In conclusion, a vaccination schedule involving three SC doses before calving would be enough to stimulate antibodies production in milk without an IMD. Furthermore, the results showed a bactericidal effect of serum from vaccinated animals and this provides further evidence about serum functionality. Immune responses, humoral (antigen-specific antibodies and Th2 type cytokines) and cellular (T-lymphocyte proliferation responses and Th1 type cytokines), were

  1. 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.

  2. Rescue of a vaccine strain of peste des petits ruminants virus: In vivo evaluation and comparison with standard vaccine.

    PubMed

    Muniraju, Murali; Mahapatra, Mana; Buczkowski, Hubert; Batten, Carrie; Banyard, Ashley C; Parida, Satya

    2015-01-01

    Across the developing world peste des petits ruminants virus places a huge disease burden on agriculture, primarily affecting the production of small ruminant. The disease is most effectively controlled by vaccinating sheep and goats with live attenuated vaccines that provide lifelong immunity. However, the current vaccines and serological tests are unable to enable Differentiation between naturally Infected and Vaccinated Animals (DIVA). This factor precludes meaningful assessment of vaccine coverage and epidemiological surveillance based on serology, in turn reducing the efficiency of control programmes. The availability of a recombinant PPRV vaccine with a proven functionality is a prerequisite for the development of novel vaccines that may enable the development of DIVA tools for PPRV diagnostics. In this study, we have established an efficient reverse genetics system for PPRV Nigeria 75/1 vaccine strain and, further rescued a version of PPRV Nigeria 75/1 vaccine strain that expresses eGFP as a novel transcription cassette and a version of PPRV Nigeria 75/1 vaccine strain with mutations in the haemagglutinin (H) gene to enable DIVA through disruption of binding to H by the C77 monoclonal antibody used in the competitive (c) H-ELISA. All three rescued viruses showed similar growth characteristics in vitro in comparison to parent vaccine strain and, following in vivo assessment the H mutant provided full protection in goats. Although the C77 monoclonal antibody used in the cH-ELISA was unable to bind to the mutated form of H in vitro, the mutation was not sufficient to enable DIVA in vivo. PMID:25444790

  3. Rescue of a vaccine strain of peste des petits ruminants virus: In vivo evaluation and comparison with standard vaccine

    PubMed Central

    Muniraju, Murali; Mahapatra, Mana; Buczkowski, Hubert; Batten, Carrie; Banyard, Ashley C.; Parida, Satya

    2015-01-01

    Across the developing world peste des petits ruminants virus places a huge disease burden on agriculture, primarily affecting the production of small ruminant. The disease is most effectively controlled by vaccinating sheep and goats with live attenuated vaccines that provide lifelong immunity. However, the current vaccines and serological tests are unable to enable Differentiation between naturally Infected and Vaccinated Animals (DIVA). This factor precludes meaningful assessment of vaccine coverage and epidemiological surveillance based on serology, in turn reducing the efficiency of control programmes. The availability of a recombinant PPRV vaccine with a proven functionality is a prerequisite for the development of novel vaccines that may enable the development of DIVA tools for PPRV diagnostics. In this study, we have established an efficient reverse genetics system for PPRV Nigeria 75/1 vaccine strain and, further rescued a version of PPRV Nigeria 75/1 vaccine strain that expresses eGFP as a novel transcription cassette and a version of PPRV Nigeria 75/1 vaccine strain with mutations in the haemagglutinin (H) gene to enable DIVA through disruption of binding to H by the C77 monoclonal antibody used in the competitive (c) H-ELISA. All three rescued viruses showed similar growth characteristics in vitro in comparison to parent vaccine strain and, following in vivo assessment the H mutant provided full protection in goats. Although the C77 monoclonal antibody used in the cH-ELISA was unable to bind to the mutated form of H in vitro, the mutation was not sufficient to enable DIVA in vivo. PMID:25444790

  4. Detection of Novel Rotavirus Strain by Vaccine Postlicensure Surveillance

    PubMed Central

    Teel, Elizabeth N.; Mijatovic-Rustempasic, Slavica; Payne, Daniel C.; Roy, Sunando; Foytich, Kimberly; Parashar, Umesh D.; Gentsch, Jon R.; Bowen, Michael D.

    2013-01-01

    Surveillance for rotavirus-associated diarrhea after implementation of rotavirus vaccination can assess vaccine effectiveness and identify disease-associated genotypes. During active vaccine postlicensure surveillance in the United States, we found a novel rotavirus genotype, G14P[24], in a stool sample from a child who had diarrhea. Unusual rotavirus strains may become more prevalent after vaccine implementation. PMID:23876297

  5. Ethanol production characteristics for a respiratory deficient mutant yeast strain

    SciTech Connect

    Garcia, A. III; Grilione, P.

    1982-01-01

    Barley was fermented with a defined strain of Saccharomyces cerevisiae and a chemical induced respiratory deficient mutant RD, specific gravity, pH, CO/sub 2/ production and ethanol production rates and yield were compared. RD fermentation were slower but yielded slightly more ethanol after a considerable time. Partial reversion to a respiratory capable strain occurred.

  6. Prevention of egg contamination by Salmonella Enteritidis after oral vaccination of laying hens with Salmonella Enteritidis ΔtolC and ΔacrABacrEFmdtABC mutants.

    PubMed

    Kilroy, Sofie; Raspoet, Ruth; Haesebrouck, Freddy; Ducatelle, Richard; Van Immerseel, Filip

    2016-01-01

    Vaccination of laying hens has been successfully used to reduce egg contamination by Salmonella Enteritidis, decreasing human salmonellosis cases worldwide. Currently used vaccines for layers are either inactivated vaccines or live attenuated strains produced by mutagenesis. Targeted gene deletion mutants hold promise for future vaccines, because specific bacterial functions can be removed that may improve safety and allow differentiation from field strains. In this study, the efficacy of Salmonella Enteritidis ΔtolC and ΔacrABacrEFmdtABC strains in laying hens as live vaccines was evaluated. The mutants are deficient in either the membrane channel TolC (ΔtolC) or the multi-drug efflux systems acrAB, acrEF and mdtABC (ΔacrABacrEFmdtABC). These strains have a decreased ability for gut and tissue colonization and are unable to survive in egg white, the latter preventing transmission of the vaccine strains to humans. Two groups of 30 laying hens were orally inoculated at day 1, 6 weeks and 16 weeks of age with 10(8) cfu of either vaccine strain, while a third group was left unvaccinated. At 24 weeks of age, the birds were intravenously challenged with 5 × 10(7) cfu Salmonella Enteritidis PT4 S1400/94. The vaccine strains were not shed or detected in the gut, internal organs or eggs, 2 weeks after the third vaccination. The strains significantly protected against gut and internal organ colonization, and completely prevented egg contamination by Salmonella Enteritidis under the conditions of this study. This indicates that Salmonella Enteritidis ΔtolC and ΔacrABacrEFmdtABC strains might be valuable strains for vaccination of layers against Salmonella Enteritidis. PMID:27519174

  7. Bovine herpesvirus-1: evaluation of genetic diversity of subtypes derived from field strains of varied clinical syndromes and their relationship to vaccine strains.

    PubMed

    Fulton, R W; d'Offay, J M; Eberle, R; Moeller, R B; Campen, H Van; O'Toole, D; Chase, C; Miller, M M; Sprowls, R; Nydam, D V

    2015-01-15

    Bovine herpesvirus-1 (BoHV-1) causes significant disease in cattle. Control programs in North America incorporate vaccination with modified live viral (MLV) or killed (KV) vaccine. BoHV-1 strains are isolated from diseased animals or fetuses after vaccination. There are markers for differentiating MLV from field strains using whole-genome sequencing and analysis identifying single nucleotide polymorphisms (SNPs). Using multiple primer sets and sequencing of products permits association of BoHV-1 isolates with vaccines. To determine association between vaccine virus and strains isolated from clinical cases following vaccination, we analyzed 12 BoHV-1 isolates from animals with various clinical syndromes; 9 corresponded to BoHV-1.1 respiratory group. The remaining three corresponded to BoHV-1.2b, typically found in genital tracts of cattle. Four BoHV-1 isolates were identical to a vaccine strain; three were from post-vaccination abortion episodes with typical herpetic lesions whose dams had received MLV vaccine during pregnancy, and one from a heifer given a related MLV vaccine; Sequences of two respiratory isolates perfectly matched mutations characterizing RLB106 strain, a temperature sensitive mutant used in intranasal and parenteral vaccines. The last three respiratory strains clearly appeared related to a group of MLV vaccines. Previously the MLV vaccines were grouped into four groups based on SNPs patterns. In contrast with above-mentioned isolates that closely matched SNP patterns of their respective MLV vaccine virus, these 3 strains both lacked some and possessed a number of additional mutations compared to a group of MLV vaccine viral genome. Finding BoHV-1.2b in respiratory cases indicates focus should be given BoHV-1.2b as an emerging virus or a virus not recognized nor fully characterized in BRD. PMID:25454086

  8. 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.

  9. Viable Newcastle Disease Vaccine Strains in a Pharmaceutical Dump

    PubMed Central

    Bianchi, Silvia; Canuti, Marta; Zappa, Alessandra; Zanoni, Giovanna; Koncan, Raffaella; Tanzi, Elisabetta; Cornaglia, Giuseppe; Zanetti, Alessandro Remo; Tridente, Giuseppe

    2007-01-01

    To assess the viability of discarded and buried vaccine strains, we examined vaccines that had been buried for >20 years in an industrial waste dump in the city of Milan, Italy. Viability results showed potential biological risk associated with uncontrolled burial of pharmaceutical industry waste, including some live vaccines. PMID:18258042

  10. Transmission of a live Eimeria acervulina vaccine strain and response to infection in vaccinated and contact-vaccinated broilers.

    PubMed

    Velkers, Francisca C; Bouma, Annemarie; Stegeman, J Arjan; de Jong, Mart C M

    2012-01-01

    Live vaccines for coccidiosis control are infrequently used in broilers, mainly due to variability in efficacy and relatively high costs. More insight in transmission of vaccine and wild-type strains can facilitate optimization of vaccination strategies and might increase its use as an alternative for anticoccidial drugs. The aim of this study was to quantify transmission of a live Eimeria acervulina vaccine strain and to determine the degree of protection against a subsequent infection with a wild-type E. acervulina strain. An experiment was carried out with 4 groups of 22 SPF broilers. At 2 days of age, 11 birds of groups 2 to 4 were vaccinated directly by oral application of E. acervulina oocysts of the Paracox™ vaccine and 11 birds were placed in contact with these birds (contact-vaccinated). Birds in group 1 remained unvaccinated (controls) and were not exposed to vaccinated birds. At day 28 of age, 6 groups of 10 birds were formed, with 2 groups (duplo) for each treatment group, i.e. vaccinated, contact-vaccinated or unvaccinated control birds. Five birds of each group were orally inoculated with wild-type E. acervulina oocysts and five were contact-exposed. Single droppings were examined daily from days 5 to 49 of age for oocyst output and to determine the time of infection. The transmission rate of the vaccine strain was estimated to be 1.6 per day and of the wild-type strain 2.3, 8.7 and 20.8 per day for vaccinated, contact-vaccinated and unvaccinated birds, respectively. Although transmission of wild-type coccidia was not significantly reduced in vaccinated or contact-vaccinated groups, both groups were equally protected against high oocyst output after infection compared to unvaccinated groups. These results suggest that factors influencing transmission of live vaccine strains in flocks may be important targets for improvement of vaccine efficacy and warrant further research. PMID:22075084

  11. Increases of efficacy as vaccine against Brucella abortus infection in mice by simultaneous inoculation with avirulent smooth bvrS/bvrR and rough wbkA mutants.

    PubMed

    Grilló, María Jesús; Manterola, Lorea; de Miguel, María Jesús; Muñoz, Pilar María; Blasco, José María; Moriyón, Ignacio; López-Goñi, Ignacio

    2006-04-01

    The Brucella abortus S19 and RB51 strains are the most widely used live vaccines against bovine brucellosis. However, both can induce abortion and milk excretion, S19 vaccination interferes in serological tests, and RB51 is less effective. We have shown previously that a rough wbkAB. abortus mutant is attenuated and a better vaccine than RB51 in BALB/c mice, and that mutants in the two-component regulatory system bvrS/bvrR are markedly attenuated while keeping a smooth lipopolysaccharide (S-LPS). In this work, we tested whether simultaneous inoculation with live bvrS increases wbkA vaccine efficacy in mice. Even at high doses, the bvrS mutant was cleared much faster from spleens than the wbkA mutant. The splenic persistence of the wbkA mutant increased when inoculated along with the bvrS mutant, but also with inactivated bvrS cells or with purified B. abortus S-LPS, strongly suggesting that S-LPS in the bvrS mutant played a determinant role in the wbkA persistence. When inoculated alone, both mutants protected against virulent B. abortus but less than when inoculated simultaneously, and the protection afforded by the combination was better than that obtained with B. abortus S19. Increased protection was also obtained after simultaneous inoculation of the wbkA mutant and inactivated bvrS cells or purified S-LPS, showing again the role played by the S-LPS in the bvrS cells. In mice, the bvrS-wbkA combination induced an antibody response reduced with respect to B. abortus S19 vaccination. Thus, the simultaneous use of live bvrS and wbkA B. abortus mutants seems a promising approach to overcome the problems of the S19 andRB51 vaccines. PMID:16439039

  12. Nonreplicating, Cyst-Defective Type II Toxoplasma gondii Vaccine Strains Stimulate Protective Immunity against Acute and Chronic Infection

    PubMed Central

    2015-01-01

    Live attenuated vaccine strains, such as type I nonreplicating uracil auxotroph mutants, are highly effective in eliciting lifelong immunity to virulent acute infection by Toxoplasma gondii. However, it is currently unknown whether vaccine-elicited immunity can provide protection against acute infection and also prevent chronic infection. To address this problem, we developed nonreverting, nonreplicating, live attenuated uracil auxotroph vaccine strains in the type II Δku80 genetic background by targeting the deletion of the orotidine 5′-monophosphate decarboxylase (OMPDC) and uridine phosphorylase (UP) genes. Deletion of OMPDC induced a severe uracil auxotrophy with loss of replication, loss of virulence in mice, and loss of the ability to develop cysts and chronic infection. Vaccination of mice using type II Δku80 Δompdc mutants stimulated a fully protective CD8+ T cell-dependent immunity that prevented acute infection by type I and type II strains of T. gondii, and this vaccination also severely reduced or prevented cyst formation after type II challenge infection. Nonreverting, nonreplicating, and non-cyst-forming Δompdc mutants provide new tools to examine protective immune responses elicited by vaccination with a live attenuated type II vaccine. PMID:25776745

  13. Nonreplicating, cyst-defective type II Toxoplasma gondii vaccine strains stimulate protective immunity against acute and chronic infection.

    PubMed

    Fox, Barbara A; Bzik, David J

    2015-05-01

    Live attenuated vaccine strains, such as type I nonreplicating uracil auxotroph mutants, are highly effective in eliciting lifelong immunity to virulent acute infection by Toxoplasma gondii. However, it is currently unknown whether vaccine-elicited immunity can provide protection against acute infection and also prevent chronic infection. To address this problem, we developed nonreverting, nonreplicating, live attenuated uracil auxotroph vaccine strains in the type II Δku80 genetic background by targeting the deletion of the orotidine 5'-monophosphate decarboxylase (OMPDC) and uridine phosphorylase (UP) genes. Deletion of OMPDC induced a severe uracil auxotrophy with loss of replication, loss of virulence in mice, and loss of the ability to develop cysts and chronic infection. Vaccination of mice using type II Δku80 Δompdc mutants stimulated a fully protective CD8(+) T cell-dependent immunity that prevented acute infection by type I and type II strains of T. gondii, and this vaccination also severely reduced or prevented cyst formation after type II challenge infection. Nonreverting, nonreplicating, and non-cyst-forming Δompdc mutants provide new tools to examine protective immune responses elicited by vaccination with a live attenuated type II vaccine. PMID:25776745

  14. Evaluation of aroA deletion mutant of Salmonella enterica subspecies enterica serovar Abortusequi for its vaccine candidate potential.

    PubMed

    Alam, Javad; Singh, B R; Hansda, D; Singh, V P; Verma, J C

    2009-11-01

    The present study on a defined deletion aroA mutant (B-26) of Salmonella enterica subspecies enterica serovar Abortusequi (S. Abortusequi) for residual virulence and safety in experimental model revealed that the virulence of the strain was at no difference in any of the cell assays (caprine alveolar macrophages, bovine alveolar macrophages, guinea pig blood mononuclear cells and horse blood mononuclear cells) than that of its parent virulence plasmid cured (S-787) and wild type (E-156) strains. The mutant did not cause any apparent illness in baby guinea pigs (15 days old), adult male and female guinea pigs and also not in pregnant (54-55 days of gestation) guinea pigs through oral (4.2 x 10(9) cfu/ animal) and intramuscular (im) routes (4.2 x 10(7) cfu/ animal). In pregnant females the mutant also induced abortion as its parent (E-156) though to lesser extent (33%) than the parent strain (100%) on inoculation through intravaginal (4.2 x 10(9) cfu/ animal) and intraperitoneal (4.2 x 10(7) cfu/ animal) routes. The babies born from mutant inoculated mothers survived better and were also resistant to intraperitoneal lethal challenge (7.82 x 10(9) cfu/ animal) with 100% protection. Female guinea pigs challenged after 135-165 days of inoculation with the mutant afforded 100% protection from abortion and mortality caused by lethal infection (7.82 x 10(9) cfu/ animal) of wild type S. enterica Abortusequi (E-156). The study revealed that aroA mutant (B-26) was safe through oral and im routes for immunization and afforded 100% protection against salmonellosis for more than 5.5 months in guinea pigs. Although immunization with aroA mutant in experimental model afforded good protection against abortion and mortality induced by S. Abortusequi, further studies are needed in horses to exploit the strain's vaccine potential in the natural host. PMID:20099460

  15. Meningococcal Factor H Binding Proteins in Epidemic Strains from Africa: Implications for Vaccine Development

    PubMed Central

    Pajon, Rolando; Fergus, Andrew M.; Koeberling, Oliver; Caugant, Dominique A.; Granoff, Dan M.

    2011-01-01

    Background Factor H binding protein (fHbp) is an important antigen for vaccines against meningococcal serogroup B disease. The protein binds human factor H (fH), which enables the bacteria to resist serum bactericidal activity. Little is known about the vaccine-potential of fHbp for control of meningococcal epidemics in Africa, which typically are caused by non-group B strains. Methodology/Principal Findings We investigated genes encoding fHbp in 106 serogroup A, W-135 and X case isolates from 17 African countries. We determined complement-mediated bactericidal activity of antisera from mice immunized with recombinant fHbp vaccines, or a prototype native outer membrane vesicle (NOMV) vaccine from a serogroup B mutant strain with over-expressed fHbp. Eighty-six of the isolates (81%) had one of four prevalent fHbp sequence variants, ID 4/5 (serogroup A isolates), 9 (W-135), or 74 (X) in variant group 1, or ID 22/23 (W-135) in variant group 2. More than one-third of serogroup A isolates and two-thirds of W-135 isolates tested had low fHbp expression while all X isolates tested had intermediate or high expression. Antisera to the recombinant fHbp vaccines were generally bactericidal only against isolates with fHbp sequence variants that closely matched the respective vaccine ID. Low fHbp expression also contributed to resistance to anti-fHbp bactericidal activity. In contrast to the recombinant vaccines, the NOMV fHbp ID 1 vaccine elicited broad anti-fHbp bactericidal activity, and the antibodies had greater ability to inhibit binding of fH to fHbp than antibodies elicited by the control recombinant fHbp ID 1 vaccine. Conclusion/Significance NOMV vaccines from mutants with increased fHbp expression elicit an antibody repertoire with greater bactericidal activity than recombinant fHbp vaccines. NOMV vaccines are promising for prevention of meningococcal disease in Africa and could be used to supplement coverage conferred by a serogroup A polysaccharide-protein conjugate

  16. 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

  17. Symptomatic Infection and Detection of Vaccine and Vaccine-Reassortant Rotavirus Strains in 5 Children: A Case Series

    PubMed Central

    Boom, Julie A.; Sahni, Leila C.; Payne, Daniel C.; Gautam, Rashi; Lyde, Freda; Mijatovic-Rustempasic, Slavica; Bowen, Michael D.; Tate, Jacqueline E.; Rench, Marcia A.; Gentsch, Jon R.; Parashar, Umesh D.; Baker, Carol J.

    2015-01-01

    Vaccine or vaccine-reassortant rotavirus strains were detected in fecal specimens from 5 of 106 (4.7%) immunocompetent children who required treatment for rotavirus gastroenteritis at a large pediatric hospital in Texas in 2009–2010. Four strains were related to pentavalent rotavirus vaccine, whereas one was related to monovalent rotavirus vaccine. The contribution of these strains to each patient’s illness was unclear given that 2 patients had prominent respiratory symptoms and 2 were concurrently infected with another pathogen (group F adenovirus and norovirus). Continued monitoring is necessary to assess the role of vaccine strains and vaccine-reassortant strains in pediatric rotavirus infections. PMID:22872730

  18. A Mutant Library Approach to Identify Improved Meningococcal Factor H Binding Protein Vaccine Antigens

    PubMed Central

    Konar, Monica; Rossi, Raffaella; Walter, Helen; Pajon, Rolando; Beernink, Peter T.

    2015-01-01

    Factor H binding protein (FHbp) is a virulence factor used by meningococci to evade the host complement system. FHbp elicits bactericidal antibodies in humans and is part of two recently licensed vaccines. Using human complement Factor H (FH) transgenic mice, we previously showed that binding of FH decreased the protective antibody responses to FHbp vaccination. Therefore, in the present study we devised a library-based method to identify mutant FHbp antigens with very low binding of FH. Using an FHbp sequence variant in one of the two licensed vaccines, we displayed an error-prone PCR mutant FHbp library on the surface of Escherichia coli. We used fluorescence-activated cell sorting to isolate FHbp mutants with very low binding of human FH and preserved binding of control anti-FHbp monoclonal antibodies. We sequenced the gene encoding FHbp from selected clones and introduced the mutations into a soluble FHbp construct. Using this approach, we identified several new mutant FHbp vaccine antigens that had very low binding of FH as measured by ELISA and surface plasmon resonance. The new mutant FHbp antigens elicited protective antibody responses in human FH transgenic mice that were up to 20-fold higher than those elicited by the wild-type FHbp antigen. This approach offers the potential to discover mutant antigens that might not be predictable even with protein structural information and potentially can be applied to other microbial vaccine antigens that bind host proteins. PMID:26057742

  19. A Mutant Library Approach to Identify Improved Meningococcal Factor H Binding Protein Vaccine Antigens.

    PubMed

    Konar, Monica; Rossi, Raffaella; Walter, Helen; Pajon, Rolando; Beernink, Peter T

    2015-01-01

    Factor H binding protein (FHbp) is a virulence factor used by meningococci to evade the host complement system. FHbp elicits bactericidal antibodies in humans and is part of two recently licensed vaccines. Using human complement Factor H (FH) transgenic mice, we previously showed that binding of FH decreased the protective antibody responses to FHbp vaccination. Therefore, in the present study we devised a library-based method to identify mutant FHbp antigens with very low binding of FH. Using an FHbp sequence variant in one of the two licensed vaccines, we displayed an error-prone PCR mutant FHbp library on the surface of Escherichia coli. We used fluorescence-activated cell sorting to isolate FHbp mutants with very low binding of human FH and preserved binding of control anti-FHbp monoclonal antibodies. We sequenced the gene encoding FHbp from selected clones and introduced the mutations into a soluble FHbp construct. Using this approach, we identified several new mutant FHbp vaccine antigens that had very low binding of FH as measured by ELISA and surface plasmon resonance. The new mutant FHbp antigens elicited protective antibody responses in human FH transgenic mice that were up to 20-fold higher than those elicited by the wild-type FHbp antigen. This approach offers the potential to discover mutant antigens that might not be predictable even with protein structural information and potentially can be applied to other microbial vaccine antigens that bind host proteins. PMID:26057742

  20. A Colanic Acid Operon Deletion Mutation Enhances Induction of Early Antibody Responses by Live Attenuated Salmonella Vaccine Strains

    PubMed Central

    Wang, Shifeng; Shi, Huoying; Li, Yuhua; Shi, Zhaoxing; Zhang, Xin; Baek, Chang-Ho; Mothershead, Tabor

    2013-01-01

    Colanic acid (CA) is a common exopolysaccharide produced by many genera in the Enterobacteriaceae. It is critical for biofilm formation on HEp-2 cells and on chicken intestinal tissue by Salmonella. In this study, we generated different CA synthesis gene mutants and evaluated the immune responses induced by these mutants. One of these mutations, Δ(wza-wcaM)8, which deleted the whole operon for CA synthesis, was introduced into two Salmonella vaccine strains attenuated by auxotrophic traits or by the regulated delayed attenuation strategy (RDAS). The mice immunized with the auxotrophic Salmonella vaccine strain with the deletion mutation Δ(wza-wcaM)8 developed higher vaginal IgA titers against the heterologous protective antigen and higher levels of antigen-specific IgA secretion cells in lungs. In Salmonella vaccine strains with RDAS, the strain with the Δ(wza-wcaM)8 mutation resulted in higher levels of protective antigen production during in vitro growth. Mice immunized with this strain developed higher serum IgG and mucosal IgA antibody responses at 2 weeks. This strain also resulted in better gamma interferon (IFN-γ) responses than the strain without this deletion at doses of 108 and 109 CFU. Thus, the mutation Δ(wza-wcaM)8 will be included in various recombinant attenuated Salmonella vaccine (RASV) strains with RDAS derived from Salmonella enterica serovar Paratyphi A and Salmonella enterica serovar Typhi to induce protective immunity against bacterial pathogens. PMID:23774599

  1. A colanic acid operon deletion mutation enhances induction of early antibody responses by live attenuated Salmonella vaccine strains.

    PubMed

    Wang, Shifeng; Shi, Huoying; Li, Yuhua; Shi, Zhaoxing; Zhang, Xin; Baek, Chang-Ho; Mothershead, Tabor; Curtiss, Roy

    2013-09-01

    Colanic acid (CA) is a common exopolysaccharide produced by many genera in the Enterobacteriaceae. It is critical for biofilm formation on HEp-2 cells and on chicken intestinal tissue by Salmonella. In this study, we generated different CA synthesis gene mutants and evaluated the immune responses induced by these mutants. One of these mutations, Δ(wza-wcaM)8, which deleted the whole operon for CA synthesis, was introduced into two Salmonella vaccine strains attenuated by auxotrophic traits or by the regulated delayed attenuation strategy (RDAS). The mice immunized with the auxotrophic Salmonella vaccine strain with the deletion mutation Δ(wza-wcaM)8 developed higher vaginal IgA titers against the heterologous protective antigen and higher levels of antigen-specific IgA secretion cells in lungs. In Salmonella vaccine strains with RDAS, the strain with the Δ(wza-wcaM)8 mutation resulted in higher levels of protective antigen production during in vitro growth. Mice immunized with this strain developed higher serum IgG and mucosal IgA antibody responses at 2 weeks. This strain also resulted in better gamma interferon (IFN-γ) responses than the strain without this deletion at doses of 10(8) and 10(9) CFU. Thus, the mutation Δ(wza-wcaM)8 will be included in various recombinant attenuated Salmonella vaccine (RASV) strains with RDAS derived from Salmonella enterica serovar Paratyphi A and Salmonella enterica serovar Typhi to induce protective immunity against bacterial pathogens. PMID:23774599

  2. The ERA strain of rabies vaccine.

    PubMed

    Lawson, K F; Crawley, J F

    1972-10-01

    An antigenic extinction trial in cats showed that the ERA rabies vaccine had superior antigenic properties over Flury H.E.P. C.E.O. and killed tissue culture rabies vaccine. Dogs and cats on a duration of immunity study of ERA rabies vaccine were challenged with fox salivary gland "street" rabies virus. The results of this challenge show a duration of immunity of five years in dogs and four years in cats. Vaccination of dams in late pregnancy with ERA rabies vaccine resulted in transference of maternal antibody to the newborn, in both cattle and dogs. This maternally derived antibody interfered with the successful active immunization of the young calf. Calves free of antibodies for rabies could be successfully vaccinated as early as 17 days of age and were able to withstand a challenge with virulent "street" rabies virus two years later. PMID:4263912

  3. The ERA Strain of Rabies Vaccine

    PubMed Central

    Lawson, K. F.; Crawley, J. F.

    1972-01-01

    An antigenic extinction trial in cats showed that the ERA rabies vaccine had superior antigenic properties over Flury H.E.P. C.E.O. and killed tissue culture rabies vaccine. Dogs and cats on a duration of immunity study of ERA rabies vaccine were challenged with fox salivary gland “street” rabies virus. The results of this challenge show a duration of immunity of five years in dogs and four years in cats. Vaccination of dams in late pregnancy with ERA rabies vaccine resulted in transference of maternal antibody to the newborn, in both cattle and dogs. This maternally derived antibody interfered with the successful active immunization of the young calf. Calves free of antibodies for rabies could be successfully vaccinated as early as 17 days of age and were able to withstand a challenge with virulent “street” rabies virus two years later. PMID:4263912

  4. Vaccination of rainbow trout against infectious hematopoietic necrosis (IHN) by using attenuated mutants selected by neutralizing monoclonal antibodies

    USGS Publications Warehouse

    Roberti, K.A.; Rohovec, J.S.; Winton, J.R.

    1998-01-01

    A neutralizing monoclonal antibody against infectious hematopoietic necrosis virus (IHNV) was used to select neutralization-resistant mutants from isolates of virus obtained from adult steelhead Oncorhynchus mykiss returning to the Round Butte Hatchery (RB mutants) on the Deschutes River in Oregon, USA, and from rainbow trout (nonanadromous O. mykiss) at a commercial hatchery in the Hagerman Valley of Idaho, USA (193-110 mutants). Two of the mutants, RB-1 and 193-110-4, were significantly (P 0.05) in protection among fish exposed to the RB-1 vaccine strain at a dose of 1 x 105 TCID50/mL for periods of either 1, 12, or 24 h, held for 14 d, and then challenged with the wild-type RB isolate, although the 1-h exposure seemed to be somewhat less effective. Fish were vaccinated with the RB-1 strain at 1 x 103-1 x 105 TCID50/mL for 24 h then challenged after 1, 7, 14, or 21 d with the wild-type RB isolate. No significant (P > 0.1) protection was observed at 1 d postvaccination, but the relative percent survival increased progressively at each subsequent challenge period, becoming statistically significant by day 7 (P < 0.001) and beyond. These results suggested that resistance to challenge with wild-type virus resulted from development of IHNV-specific immunity and not from viral interference or interferon induction, and they reinforce the potential of an attenuated vaccine to control this important disease.

  5. An invasive and low virulent Edwardsiella tarda esrB mutant promising as live attenuated vaccine in aquaculture.

    PubMed

    Yang, Weizheng; Wang, Lixia; Zhang, Lingzhi; Qu, Jiangbo; Wang, Qiyao; Zhang, Yuanxing

    2015-02-01

    Edwardsiella tarda is a leading fish pathogen haunting worldwide aquaculture industry. In E. tarda, two-component system EsrA-EsrB positively regulates type III and VI secretion systems (T3SS and T6SS) and negatively regulates hemolysin EthA, which has been demonstrated to be essential for the invasion processes in fish. In order to develop a live attenuated vaccine (LAV) with high invasiveness to be practically and economically used as immersion-administered vaccine in aquaculture, here, we generated a random mutation library of esrB sequences by error-prone PCR and introduced them into the E. tarda esrB deletion mutant. The mutant YWZ47 with significantly increased hemolytic activity and low T3SS and T6SS secretion was screened. Phenotypes including extracellular protein profiles, invasion in macrophages, lethality toward fish, and infection kinetics were investigated in the wild-type strain EIB202 and the mutants ΔesrB, ΔT3SS, ΔT6SS, ΔT3SS/ΔT6SS, and YWZ47. Compared to the documented LAV strain ΔesrB, YWZ47 showed higher invasive capability and low in vivo virulence toward fish. Significantly higher relative percent survival (RPS) could be generated in turbot (Scophthalmus maximus) against the challenge of the wild-type EIB202 when inoculated through immersion route, and the RPS was comparable with that of ΔesrB through intraperitoneal (i.p.) injection inoculation. Two mutated points, K167M and H197L, were found by sequence analysis of EsrBYWZ47 variant. These structural modifications underpin the variations in the regulatory functions of the mutant and wild-type EsrB. This study promoted understanding of virulence regulation by EsrB in E. tarda and presented a promising candidate of invasive attenuated vaccine used in aquaculture industries. PMID:25431010

  6. A carAB mutant of avian pathogenic Escherichia coli serogroup O2 is attenuated and effective as a live oral vaccine against colibacillosis in turkeys.

    PubMed Central

    Kwaga, J K; Allan, B J; van der Hurk, J V; Seida, H; Potter, A A

    1994-01-01

    Colibacillosis is a serious and economically important disease of the respiratory tract of chickens and turkeys. The serogroups of Escherichia coli commonly associated with colibacillosis in poultry are O1, O2, and O78. Although previous attempts to develop a vaccine have not been very successful, vaccination is still considered the most effective way of controlling the disease. Therefore, our laboratory has been involved in the development of an attenuated live vaccine that will be effective in the prevention of colibacillosis. The carAB operon coding for carbamoyl-phosphate synthetase, an essential enzyme in arginine and pyrimidine metabolism, was selected for study. Generalized transduction was used to transfer a Tn10-generated mutation from a laboratory strain to virulent avian field isolates of E. coli. Molecular techniques were used to determine the point of Tn10 insertion within the carAB operon. The insertion mutants were then cured of the tetracycline resistance gene of the transposon to select for antibiotic-sensitive and stable carAB mutants. The degree of attenuation obtained by the mutation was determined in day-old chickens. Typically, when 100-fold the 50% lethal dose (for the wild type) was given, no more than 50% mortality in the day-old chickens was observed. The deletion mutant of serotype O2 was also found to be avirulent in turkeys rendered susceptible to infection with hemorrhagic enteritis virus A. Turkey poults vaccinated orally at 4 weeks old with either the wild-type E. coli EC317 strain or its carAB mutant EC751 were completely protected from infection following challenge with the homologous wild-type strain. Our data indicate that carAB mutants of virulent avian strains of E. coli will be effective and safe as live oral vaccines for prevention of colibacillosis in poultry. Images PMID:8063392

  7. Mismatching between circulating strains and vaccine strains of influenza: Effect on Hajj pilgrims from both hemispheres.

    PubMed

    Alfelali, Mohammad; Khandaker, Gulam; Booy, Robert; Rashid, Harunor

    2016-03-01

    The trivalent seasonal influenza vaccine is expected to provide optimum protection if the vaccine strains match the circulating strains. The effect of worldwide mismatch between the vaccine strains and extant strains on travelers attending Hajj pilgrimage is not known. Annually 2-3 million Muslims coming from north and south hemispheres congregate at Hajj in Mecca, Saudi Arabia, where intense congestion amplifies the risk of respiratory infection up to eight fold. In order to estimate, to what extent mismatching increases the risk of vaccine failure in Hajj pilgrims, we have examined the global data on influenza epidemiology since 2003, in light of the available data from Hajj. These data demonstrate that globally mismatching between circulating and vaccine strains has occurred frequently over the last 12 years, and the mismatch seems to have affected the Hajj pilgrims, however, influenza virus characteristics were studied only in a limited number of Hajj seasons. When the vaccines are different, dual vaccination of travelers by vaccines for southern and northern hemispheres should be considered for Hajj pilgrims whenever logistically feasible. Consideration should also be given to the use of vaccines with broader coverage, i.e., quadrivalent, or higher immunogenicity. Continuous surveillance of influenza at Hajj is important. PMID:26317639

  8. 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

  9. Novel Attenuated Salmonella enterica Serovar Choleraesuis Strains as Live Vaccine Candidates Generated by Signature-Tagged Mutagenesis

    PubMed Central

    Ku, Yu-We; McDonough, Sean P.; Palaniappan, Raghavan U. M.; Chang, Chao-Fu; Chang, Yung-Fu

    2005-01-01

    Salmonella enterica serovar Choleraesuis is a host-adapted pathogen that causes swine paratyphoid. Signature-tagged mutagenesis (STM) was used to understand the pathogenicity of S. enterica serovar Choleraesuis in its natural host and also to develop novel attenuated live vaccine candidates against this disease. A library of 960 signature-tagged mutants of S. enterica serovar Choleraesuis was constructed and screened for attenuation in pigs. Thirty-three mutants were identified by the STM screening, and these mutants were further screened for attenuation by in vivo and in vitro competitive growth. Of these, 20 mutants targeting the outer membrane, type III secretion, transporter, lipopolysaccharide biosynthesis, and other unknown proteins were confirmed for attenuation. Five highly attenuated mutants (SC2D2 [ssaV], SC4A9 [gifsy-1], SC6F9 [dgoT], SC12B12 [ssaJ], and SC10B1[spiA]) were selected and evaluated for safety and protective efficacy in pigs by comparison with a commercially available vaccine strain. STM-attenuated live vaccine strains SC4A9 (gifsy-1) and SC2D2 (ssaV) were superior to commercially available live vaccine because they provided both safety and a protective immune response against challenge in pigs. PMID:16299315

  10. [CONSTRUCTION AND PROPERTIES OF THE FRANCISELLA TULARENSIS VACCINE STRAIN WITHOUT ONE COPY OF THE IGLC GENE AND WITHOUT RECA GENE].

    PubMed

    Mokrievich, A N; Vakhrameeva, G M; Titareva, G M; Bakhteeva, I V; Mironova, R I; Kombarova, T I; Kravchenko, T B; Dyatlov, I A; Pavlov, V M

    2015-01-01

    The live vaccine based on the Francisella tularensis subsp. holarctica vaccine strain 15 NIIEG line is used in Russia against tularemia. This vaccine is highly effective, but fairly unstable. Therefore, development of stable live tularemia vaccine with minimal side effect is rather urgent. The method of allel removal in the F. tularensis vaccine strain was used to remove one copy of the iglC gene, which is required to provide intracellular production of the vaccine strain, as well as removal of the recA gene. The latter is crucial for homological recombination. pGM5 suicide vector based on pHV33 bireplicon plasmid was constructed to provide replacement of intact F. tularensis chromosome segments by modified segments. Modified chromosome segments contain F. Tularensis DNA fragment without iglC structural gene segment 545 p. b. (in pGMΔiglC plasmid), as well as DNA fragment containing no recA structural gene segment 1060 p.b. (pGMΔrecA plasmid). The constructed 15/23-1ΔrecA mutant, in contrast to the vaccine strain 15, was capable of reproducing in the macrophage-like cells J774A.1 line, whereas the efficiency of the reproduction was 8-10 times less. BALB/c mouse responded to immunization by the 15/23-1ΔrecA strain by smaller weight decrease (-2%) as compared to the strain 15 (-14%). Bacteria of the 15/23-1ΔrecA strain were virtually incapable of germinating from the BALB/c murine spleen 14 days after invasion, whereas bacteria of the strain 15 were found in the murine organs even after 21 days. The F. tularensis 15/23-1ΔrecA strain having smaller reaction ability can be used as a basis for construction of stable live safe tularemia vaccine. PMID:26665740

  11. Mutants of Paracoccidioides brasiliensis strain IVIC Pb9 affected in dimorphism.

    PubMed

    San-Blas, F; San-Blas, G

    1992-01-01

    Morphological mutants were isolated after nitrosoguanidine treatment of Paracoccidioides brasiliensis strain IVIC Pb9. Two of these mutants, Pb257 and Pb258, developed a typical mycelia at 23 degrees C, however, the yeast cells which developed at 37 degrees C were indistinguishable from those of the parental strain. A third mutant, strain Pb267, was thermosensitive, grew as yeast-like cells at 23 degrees C, but was unable to survive at 37 degrees C. Morphological observations as well as serological and segregation tests confirmed that the mutant strains originated from P. brasiliensis. Cell wall chemical analyses of the mutant strains grown at 23 degrees C indicated the presence of alkali-soluble, acid-insoluble polysaccharides absent in the parental wild-type strain Pb9 grown under the same conditions. The phenotypes shown by the mutant strains may be related to deficiencies in the proper synthesis of cell wall components of the mycelial phase of this fungus. PMID:1573521

  12. 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

  13. Biofilm formation by exopolysaccharide mutants of Leuconostoc mesenteroides strain NRRL B-1355

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Leuconostoc mesenteroides strain NRRL B-1355 produces the soluble exopolysaccharides alternan and dextran in planktonic cultures. A set of mutants of this strain are available that are deficient in the production of alternan, dextran, or both. Another mutant of NRRL B-1355, strain R1510, produces ...

  14. The efficacy of Mycoplasma gallisepticum K-strain live vaccine in broiler and layer chickens.

    PubMed

    Ferguson-Noel, N M; Williams, S M

    2015-01-01

    The efficacy of a live Mycoplasma gallisepticum (MG) vaccine candidate (K-strain) was compared to commercially available vaccines in broiler-type chickens (Trial 1) and layer-type chickens (Trial 2). In Trial 1, three-week-old broiler-type chickens were vaccinated via aerosol with K-strain or an F-strain vaccine. The vaccinated chickens and 10 non-vaccinated controls were subsequently challenged with virulent R-strain via aerosol at six weeks post vaccination; both K-strain and F-strain vaccination resulted in significant protection from air sac and tracheal lesions, as well as R-strain colonization (P ≤ 0.05). In Trial 2, commercial layer-type chickens were vaccinated with ts-11 (via eye drop) or K-strain (via aerosol) at 12 weeks of age. At 25 weeks of age these birds were challenged with R-strain via aerosol. The ts-11 and K-strain vaccinated groups both had significantly lower air sac lesion scores and a lower prevalence of ovarian regression after challenge as compared to non-vaccinated chickens (P ≤ 0.05). K-strain vaccination also prevented significant tracheal lesions and R-strain colonization (P ≤ 0.05). K-strain shows great potential as a highly efficacious live MG vaccine in broiler and layer-type chickens for protection of the respiratory and reproductive systems as well as prevention of infection with field strains. PMID:25571953

  15. Generation and Evaluation of High β-Glucan Producing Mutant Strains of Sparassis crispa

    PubMed Central

    Kim, Seung-Rak; Kang, Hyeon-Woo

    2013-01-01

    A chemical mutagenesis technique was employed for development of mutant strains of Sparassis crispa targeting the shortened cultivation time and the high β-glucan content. The homogenized mycelial fragments of S. crispa IUM4010 strain were treated with 0.2 vol% methyl methanesulfonate, an alkylating agent, yielding 199 mutant strains. Subsequent screening in terms of growth and β-glucan content yielded two mutant strains, B4 and S7. Both mutants exhibited a significant increase in β-glucan productivity by producing 0.254 and 0.236 mg soluble β-glucan/mg dry cell weight for the B4 and S7 strains, respectively, whereas the wild type strain produced 0.102 mg soluble β-glucan/mg dry cell weight. The results demonstrate the usefulness of chemical mutagenesis for generation of mutant mushroom strains. PMID:24198672

  16. Francisella tularensis type B ΔdsbA mutant protects against type A strain and induces strong inflammatory cytokine and Th1-like antibody response in vivo.

    PubMed

    Straskova, Adela; Spidlova, Petra; Mou, Sherry; Worsham, Patricia; Putzova, Daniela; Pavkova, Ivona; Stulik, Jiri

    2015-11-01

    Francisella tularensis subspecies tularensis is a highly virulent intracellular bacterial pathogen, causing the disease tularemia. However, a safe and effective vaccine for routine application against F. tularensis has not yet been developed. We have recently constructed the deletion mutants for the DsbA homolog protein (ΔdsbA/FSC200) and a hypothetical protein IglH (ΔiglH/FSC200) in the type B F. tularensis subsp. holarctica FSC200 strain, which exerted different protection capacity against parental virulent strain. In this study, we further investigated the immunological correlates for these different levels of protection provided by ΔdsbA/FSC200 and ΔiglH/FSC200 mutants. Our results show that ΔdsbA/FSC200 mutant, but not ΔiglH/FSC200 mutant, induces an early innate inflammatory response leading to strong Th1-like antibody response. Furthermore, vaccination with ΔdsbA/FSC200 mutant, but not with ΔiglH/FSC200, elicited protection against the subsequent challenge with type A SCHU S4 strain in mice. An immunoproteomic approach was used to map a spectrum of antigens targeted by Th1-like specific antibodies, and more than 80 bacterial antigens, including novel ones, were identified. Comparison of tularemic antigens recognized by the ΔdsbA/FSC200 post-vaccination and the SCHU S4 post-challenge sera then revealed the existence of 22 novel SCHU S4 specific antibody clones. PMID:26253078

  17. Isolation of a mutant strain of Pseudomonas sp ATCC 31461 exhibiting elevated polysaccharide production.

    PubMed

    West, T P

    2002-10-01

    A mutant strain of the bacterium Pseudomonas sp. ATCC 31461 that exhibited elevated production of the polysaccharide gellan on glucose or corn syrup as a carbon source was isolated. Gellan production by the mutant strain was about twofold higher than its parent strain on glucose or corn syrup after 48 h of growth, and about 1.4-fold higher after 72 h. An increase in biomass production was not correlated with enhanced gellan synthesis by the mutant strain. The increased gellan production by the mutant strain on either carbon source resulted in an increase in its culture medium viscosity and the viscosity of the isolated polysaccharide produced by glucose-grown cells. No differences in the glucuronic acid content of the polysaccharides produced by the mutant and parent strains were observed. PMID:12355317

  18. Vaccination with an Attenuated Ferritin Mutant Protects Mice against Virulent Mycobacterium tuberculosis

    PubMed Central

    Subbian, Selvakumar; Pandey, Ruchi; Soteropoulos, Patricia; Rodriguez, G. Marcela

    2015-01-01

    Mycobacterium tuberculosis the causative agent of tuberculosis affects millions of people worldwide. New tools for treatment and prevention of tuberculosis are urgently needed. We previously showed that a ferritin (bfrB) mutant of M. tuberculosis has altered iron homeostasis and increased sensitivity to antibiotics and to microbicidal effectors produced by activated macrophages. Most importantly, M. tuberculosis lacking BfrB is strongly attenuated in mice, especially, during the chronic phase of infection. In this study, we examined whether immunization with a bfrB mutant could confer protection against subsequent infection with virulent M. tuberculosis in a mouse model. The results show that the protection elicited by immunization with the bfrB mutant is comparable to BCG vaccination with respect to reduction of bacterial burden. However, significant distinctions in the disease pathology and host genome-wide lung transcriptome suggest improved containment of Mtb infection in animals vaccinated with the bfrB mutant, compared to BCG. We found that downmodulation of inflammatory response and enhanced fibrosis, compared to BCG vaccination, is associated with the protective response elicited by the bfrB mutant. PMID:26339659

  19. 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. PMID:27271739

  20. Efficacy of Brucella abortus vaccine strain RB51 compared to the reference vaccine Brucella abortus strain 19 in water buffalo.

    PubMed

    Caporale, Vincenzo; Bonfini, Barbara; Di Giannatale, Elisabetta; Di Provvido, Andrea; Forcella, Simona; Giovannini, Armando; Tittarelli, Manuela; Scacchia, Massimo

    2010-01-01

    Approximately 250,000 water buffalo (Bubalus bubalis) live in the Campania region of southern Italy where the breeding of this species is very popular. Of these animals, almost 150,000 are concentrated in the Caserta province where the prevalence of Brucella abortus in this species represents approximately 20% at herd level. The Italian brucellosis eradication programme provides a slaughter and vaccination strategy for this province. B. abortus strain RB51 (RB51) has become the official vaccine for the prevention of brucellosis in cattle in several countries. The aim of this study was to evaluate the efficacy of RB51 in water buffalo compared to the B. abortus S19 vaccine (S19). The study was performed in accordance with a protocol described in mice. Female buffalo aged five months were inoculated. Five received a RB51 dosage on two occasions that was three times greater than that approved for use in cattle and a booster after one month, five received B. abortus S19 vaccine at the standard dosage and three controls received a phosphate buffer solution. Buffalo were then challenged with a virulent B. abortus strain 544 thirty days post vaccination. Antibodies that developed in the five animals vaccinated with RB51 were not detected by the Rose Bengal test or complement fixation test (CFT) and were also tested by CFT prepared with RB51 antigen. After culling, B. abortus was cultured from the spleen, retropharyngeal and supra-mammary lymph nodes. A statistical evaluation was performed to assess the immunogenicity values obtained in buffalo vaccinated with S19, compared to those obtained in buffalo vaccinated with the RB51 vaccine and in the unvaccinated control group. PMID:20391363

  1. 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. PMID:20336512

  2. Identification of upregulated genes in a modified live vaccine strain of Edwardsiella ictaluri compared to a virulent parent strain and characterization of novel DNA vaccine candidates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Using PCR-select subtractive cDNA hybridization technique, 41 expressed sequence tags (EST's) were isolated from a modified live vaccine strain (AQUAVAC-ESC formerly RD-33) vs a virulent parent strain (EILO) of Edwardsiella ictaluri. Transcriptional levels of the 41 ESTs in the vaccine strain and th...

  3. 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. PMID:19716523

  4. Live Attenuated Rubella Vaccine (Cendehill Strain) in School Children

    PubMed Central

    Hutchison, Patricia A.; Izumi, Toshiaki; Davidson, W. George; Grocott, H. C.; Martin, Hulda M.

    1970-01-01

    The purpose of this study was to further determine the efficacy and safety in school children of the Cendehill strain of live attenuated rubella vaccine. Parental permission was requested for 255 children in Grades I, II and VI, attending two adjacent schools, to have blood taken for rubella hemagglutination-inhibition studies at the beginning and end of the study, and for each child seronegative on initial testing to participate as a vaccinee or a control. Vaccinees received either 0.5 ml. (full recommended dose) or 0.25 ml. of rubella virus vaccine, live attenuated, Cendehill strain (Smith Kline & French). Eighty-one per cent of the parents consented to have their child take part. Seventy-nine per cent of Grade I and II pupils and 41% of Grade VI pupils were found to be susceptible to rubella at the time of the initial test (HI titres [unk] 8). Eighty children received rubella vaccine and 98.7% showed at least a four-fold rise in antibody titre. One child who received 0.25 ml. showed only a two-fold rise. Clinical reactions to the vaccine were absent or minimal. Thirty-eight controls remained serologically negative during the study. The good response to half-doses of Cendehill vaccine is not significant because there were >3000 TCID50 in a full dose (three times the dose recommended). This information was unknown by the investigators until the termination of the study. PMID:5506107

  5. Vaccine potential of a nonflagellated, virulence-plasmid-cured (fliD-, pSEVΔ) mutant of Salmonella Enteritidis for chickens.

    PubMed

    Imre, Ariel; Szmolka, Ama; Olasz, Ferenc; Nagy, Béla

    2015-09-01

    The aim of these studies was to assess residual virulence and early protective capacity of a negatively markered live attenuated vaccine candidate Salmonella Enteritidis mutant against a highly virulent S. Enteritidis strain using a dayold chicken model. Nonflagellated FliD negative mutants of Salmonella Enteritidis 11 (SE11) with and without the virulence plasmid proved to be sufficiently attenuated (limited invasiveness in vitro/in vivo) without reduced ability to colonise chicken gut. The early protective activity of a nonflagellated, virulence-plasmidcured (fliD-, pSEVΔ) mutant against organ invasion, caecal colonisation and faecal shedding by the highly virulent challenge strain S. Enteritidis 147 Nal(R) proved to be effective and safe. The innate and adaptive immunity was demonstrable during the first four weeks of life, and the serological response was clearly distinguishable from the response induced by the wild parental strain. In conclusion, we provided data for the first time about a virulence-plasmid-cured, nonflagellated mutant of S. Enteritidis to serve as a basis for development of a negatively markered potential live oral vaccine against virulent S. Enteritidis in chicken. PMID:26551419

  6. Capripox disease in Ethiopia: Genetic differences between field isolates and vaccine strain, and implications for vaccination failure.

    PubMed

    Gelaye, Esayas; Belay, Alebachew; Ayelet, Gelagay; Jenberie, Shiferaw; Yami, Martha; Loitsch, Angelika; Tuppurainen, Eeva; Grabherr, Reingard; Diallo, Adama; Lamien, Charles Euloge

    2015-07-01

    Sheeppox virus (SPPV), goatpox virus (GTPV) and lumpy skin disease virus (LSDV) of the genus Capripoxvirus (CaPV) cause capripox disease in sheep, goats and cattle, respectively. These viruses are not strictly host-specific and their geographical distribution is complex. In Ethiopia, where sheep, goats and cattle are all affected, a live attenuated vaccine strain (KS1-O180) is used for immunization of both small ruminants and cattle. Although occurrences of the disease in vaccinated cattle are frequently reported, information on the circulating isolates and their relation to the vaccine strain in use are still missing. The present study addressed the parameters associated with vaccination failure in Ethiopia. Retrospective outbreak data were compiled and isolates collected from thirteen outbreaks in small ruminants and cattle at various geographical locations and years were analyzed and compared to the vaccine strain. Isolates of GTPV and LSDV genotypes were responsible for the capripox outbreaks in small ruminants and cattle, respectively, while SPPV was absent. Pathogenic isolates collected from vaccinated cattle were identical to those from the non-vaccinated ones. The vaccine strain, genetically distinct from the outbreak isolates, was not responsible for these outbreaks. This study shows capripox to be highly significant in Ethiopia due to low performance of the local vaccine and insufficient vaccination coverage. The development of new, more efficient vaccine strains, a GTPV strain for small ruminants and a LSDV for cattle, is needed to promote the acceptance by farmers, thus contribute to better control of CaPVs in Ethiopia. PMID:25907637

  7. Identification of over-expressed genes in modified live vaccine strain of Edwardsiella ictaluri compared to virulent strain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Using PCR-select subtractive cDNA hybridization technique, 41 expressed sequence tags (ESTs) were isolated from a modified live vaccine strain (AQUAVAC-ESC, formerly RE-33) vs a virulent parent strain (EILO) of Edwardsiella ictaluri. Transcriptional levels of the 41 ESTs in the vaccine strain and th...

  8. Stable Listeria monocytogenes live vaccine candidate strains with graded attenuation on the mouse model.

    PubMed

    Linde, K; Abraham, A A; Beer, J

    1991-02-01

    Metabolic drift (antibiotics resistance) mutations were used to construct stable two (and three) marker vaccine candidate strains of the predominant Listeria monocytogenes serotypes 1/2a and 4b by stepwise selection. Derived from wild-type strains, spontaneous chromosomal streptomycin-resistant clones with their i.p. LD50 elevated from less than or equal to 10(5.0) c.f.u. to approximately 10(6.1) c.f.u. were used in the second step to isolate the rifampicin-resistant mutants with i.p. LD50 values ranging from 10(6.6) to 10(7.4). On i.p. immunization with fully tolerated doses (less than or equal to 1% LD50), these potential vaccine strains were found to protect not less than 95% of the mice against a lethal (approximately 100 LD50) challenge with the homologous wild-type strain. Further elevation of the i.p. LD50 to greater than 10(8.3) c.f.u. by means of a third attenuating fosfomycin-resistance marker resulted in overattenuation and reduced protective capacity. PMID:1905446

  9. Characterization of attenuated Renibacterium salmoninarum strains and their use as live vaccines.

    PubMed

    Daly, J G; Griffiths, S G; Kew, A K; Moore, A R; Olivier, G

    2001-03-01

    Two nutritionally mutant strains of Renibacterium salmoninarum (Rs) were isolated that grew on tryticase soy agar (Rs TSA1) or brain heart infusion agar (Rs BHI1). These 2 strains could be continuously cultured on these media, whereas typical R. salmoninarum would only grow on KDM-2 agar. We determined no other phenotypic difference that could be used to distinguish them from wild-type R. salmoninarum. Both strains were found to be avirulent when 5 x 10(6) bacteria were intraperitoneally (i.p.) injected into Atlantic salmon. Rs TSA1, Rs BHI1, and Rs MT-239 (a R. salmoninarum strain previously shown to be attenuated) were tested as live vaccines in 2 separate trials. The best protection was seen with Rs TSA1. Vaccinated Atlantic salmon had relative percent survival (RPS) of 50 at 74 d post-challenge in Trial 1 and 76 at 60 d post-challenge in Trial 2. In both trials, 100% of the control salmon died from bacterial kidney disease (BKD) (within 40 d for Trial 1 and 50 d for Trial 2) after i.p. challenge with 5 x 10(6) live cells of the virulent isolate Rs Margaree. PMID:11324812

  10. Prevention of clinical coliform mastitis in dairy cows by a mutant Escherichia coli vaccine.

    PubMed Central

    González, R N; Cullor, J S; Jasper, D E; Farver, T B; Bushnell, R B; Oliver, M N

    1989-01-01

    A prospective cohort study was undertaken in two commercial California dairies. The treatment group, 246 cows, received three doses of a whole cell bacterin of J5 Escherichia coli (mutant of E. coli O111:B4) plus Freund's incomplete adjuvant vaccine (two in the dry period and one after calving) while 240 unvaccinated cows served as controls. Thirty-five cases of clinical coliform mastitis were diagnosed, six in vaccinated cows and 29 in unvaccinated cows. Bacteria isolated from the clinical cases included 15 E. coli five Klebsiella pneumoniae, three K. oxytoca, three K. ozaenae, five Enterobacter aerogenes, three Serratia marcescens and one Serratia spp. Four control cows were culled, three of them because of chronic coliform mastitis and one because of postcoliform infection agalactia. Incidence rate of clinical gram-negative mastitis was 2.57% in vaccinated cows and 12.77% in unvaccinated cows. The estimated risk ratio, the measure of risk of having clinical gram-negative mastitis for vaccinated cows to unvaccinated cows, was 0.20 (p less than 0.005), indicating a strong relationship between vaccination and lack of clinical gram-negative mastitis. The results of this trial indicate that the administration of the E. coli J5 vaccine is protective against natural challenge to gram-negative bacteria, and reduces the incidence of clinical gram-negative mastitis in dairy cows during the first three months of lactation. PMID:2670166

  11. Use of quadrivalent human papillomavirus vaccine and the prevalence of antibodies to vaccine-targeted strains among female service members before and after vaccination.

    PubMed

    Hurt, Lee; Nsouli-Maktabi, Hala; Rohrbeck, Patricia; Clark, Leslie L

    2016-02-01

    The quadrivalent human papillomavirus vaccine (HPV4) has been shown to generate a robust immune response among fully vaccinated individuals; however, among U.S. service members, HPV vaccine completion rates are low. This study compared the immunogenicity of HPV4 vaccine among partially and fully vaccinated service members at 4-6 years post-vaccination. A random sample was obtained of 2,091 female service members, aged 17-26 years, who received 1-3 HPV4 doses during 2006-2012, stratified by number of doses (one, two, or three). Pre- and post-immunization sera from these service members were tested for antibodies to the HPV strains covered by the vaccine. Prior to immunization 42% were seropositive for HPV strain 6; 34% for strain 11; 29% for strain 16; and 16% for strain 18. Among those naive to all four strains prior to immunization, there was 100% seroconversion after one, two, or three doses. The results indicate that many service members had already been exposed to strains of HPV prior to receiving the vaccine; however, seropositivity prevalence was lower for the oncogenic HPV strains 16 and 18. The data demonstrate sustained immunogenicity after a single dose of vaccine, with modest improvement with successive doses for all strains except 18. PMID:26930146

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  13. 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. PMID:26051516

  14. Mutant strains of Tetrahymena thermophila defective in thymidine kinase activity: Biochemical and genetic characterization

    SciTech Connect

    Cornish, K.V.; Pearlman, R.E.

    1982-08-01

    Three mutant strains, one conditional, of Tetrahymena thermophila were defective in thymidine phosphorylating activity in vivo and in thymidine kinase activity in vitro. Nucleoside phosphotransferase activity in mutant cell extracts approached wild-type levels, suggesting that thymidine kinase is responsible for most, if not all, thymidine phosphorylation in vivo. Thymidine kinase activity in extracts of the conditional mutant strain was deficient when the cells were grown or assayed or both at the permissive temperature, implying a structural enzyme defect. Analysis of the reaction products from in vitro assays with partially purified enzymes showed that phosphorylation by thymidine kinase and nucleoside phosphotransferase occurred at the 5' position. Genetic analyses showed that the mutant phenotype was recessive and that mutations in each of the three mutant strains did not complement, suggesting allelism.

  15. A Wide Extent of Inter-Strain Diversity in Virulent and Vaccine Strains of Alphaherpesviruses

    PubMed Central

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

    2011-01-01

    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

  16. Induction, isolation, and characterization of aspergillus niger mutant strains producing elevated levels of beta-galactosidase.

    PubMed Central

    Nevalainen, K M

    1981-01-01

    An Aspergillus niger mutant strain, VTT-D-80144, with an improvement of three- to fourfold in the production of extracellular beta-galactosidase was isolated after mutagenesis. The production of beta-galactosidase by this mutant was unaffected by fermentor size, and the enzyme was also suitable for immobilization. PMID:6784672

  17. Use of antigenic cartography in vaccine seed strain selection.

    PubMed

    Fouchier, Ron A M; Smith, Derek J

    2010-03-01

    Human influenza A viruses are classic examples of antigenically variable pathogens that have a seemingly endless capacity to evade the host's immune response. The viral hemagglutinin (HA) and neuraminidase (NA) proteins are the main targets of our antibody response to combat infections. HA and NA continuously change to escape from humoral immunity, a process known as antigenic drift. As a result of antigenic drift, the human influenza vaccine is updated frequently. The World Health Organization (WHO) coordinates a global influenza surveillance network that, by the hemagglutination inhibition (HI) assay, routinely characterizes the antigenic properties of circulating strains in order to select new seed viruses for such vaccine updates. To facilitate a quantitative interpretation and easy visualization of HI data, a new computational technique called "antigenic cartography" was developed. Since its development, antigenic cartography has been applied routinely to assist the WHO with influenza surveillance activities. Until recently, antigenic variation was not considered a serious issue with influenza vaccines for poultry. However, because of the diversification of the Asian H5N1 lineage since 1996 into multiple genetic clades and subclades, and because of the long-term use of poultry vaccines against H5 in some parts of the world, this issue needs to be re-addressed. The antigenic properties of panels of avian H5N1 viruses were characterized by HI assay, using mammalian or avian antisera, and analyzed using antigenic cartography methods. These analyses revealed antigenic differences between circulating H5N1 viruses and the H5 viruses used in poultry vaccines. Considerable antigenic variation was also observed within and between H5N1 clades. These observations have important implications for the efficacy and long-term use of poultry vaccines. PMID:20521635

  18. Increased immunity to cottontail rabbit papillomavirus infection in EIII/JC inbred rabbits after vaccination with a mutant E6 that correlates with spontaneous regression.

    PubMed

    Hu, Jiafen; Cladel, Nancy M; Christensen, Neil D

    2007-01-01

    Our previous studies showed that a progressive cottontail rabbit papillomavirus (CRPV) strain containing a single amino acid change in E6 (E6G252E) induced papilloma regression in EIII/JC inbred rabbits. This finding implied that the point mutation might cause an increase in the antigenicity of the mutant versus the wild-type E6. To test this hypothesis, groups of four EIII/JC inbred rabbits were immunized with wild-type CRPVE6, CRPVE6G252E, CRPV E5, or with vector alone. A gene gun delivery system was used to deliver the DNA vaccines. Two of four rabbits from both E6G252E- and wild-type E6-vaccinated groups were free of papillomas at week 12 after viral challenge. Significantly smaller papillomas were found on E6G252E-vaccinated rabbits than on E6-, E5-, and control vector-vaccinated rabbits (p = 0.01, unpaired Student t test) and these small papillomas regressed at week 20 after viral challenge. E5 vaccination failed to provide protection against viral challenge, and the mean papilloma size was also comparable to that of the control vector-vaccinated rabbits (p > 0.05, unpaired Student t test). We conclude that a single amino acid change in the CRPV E6 protein (G252E) increased protection against wild-type infectious CRPV. PMID:17603848

  19. Safety and protective efficacy of a spiC and crp deletion mutant of Salmonella gallinarum as a live attenuated vaccine for fowl typhoid.

    PubMed

    Cheng, Zhao; Yin, Junlei; Kang, Xilong; Geng, Shizhong; Hu, Maozhi; Pan, Zhiming; Jiao, Xinan

    2016-08-01

    With an aim to develop a safe, immunogenic fowl typhoid (FT) vaccine, the safety and efficacy of 1009ΔspiCΔcrp, a spiC and crp deletion mutant of Salmonella gallinarum, were evaluated in chickens. Three-day-old chickens were intramuscularly immunized with 1009ΔspiCΔcrp (1×10(7)CFU) and boosted 7days later (at 10-days old) with the same dose and via the same route (vaccinated group). The vaccinated group showed no clinical symptoms and no differences in body weight compared to the unvaccinated control group. 1009ΔspiCΔcrp bacteria colonized and persisted in the liver and spleen of vaccinated chickens for >14days, and significant specific humoral and cellular immune responses were induced. Vaccinated chickens were challenged with S. gallinarum strain SG9 at 21days post-immunization (24-day-old chickens), and efficient protection was observed based on the mortality and clinical symptoms, as compared to those in the control group. These results demonstrate that 1009ΔspiCΔcrp can be used as a live attenuated vaccine. PMID:27473974

  20. Efficient production of ethanol from crude glycerol by a Klebsiella pneumoniae mutant strain.

    PubMed

    Oh, Baek-Rock; Seo, Jeong-Woo; Heo, Sun-Yeon; Hong, Won-Kyung; Luo, Lian Hua; Joe, Min-ho; Park, Don-Hee; Kim, Chul Ho

    2011-02-01

    A mutant strain of Klebsiella pneumoniae, termed GEM167, was obtained by γ irradiation, in which glycerol metabolism was dramatically affected on exposure to γ rays. Levels of metabolites of the glycerol reductive pathway, 1,3-propanediol (1,3-PD) and 3-hydroxypropionic acid (3-HP), were decreased in the GEM167 strain compared to a control strain, whereas the levels of metabolites derived from the oxidative pathway, 2,3-butanediol (2,3-BD), ethanol, lactate, and succinate, were increased. Notably, ethanol production from glycerol was greatly enhanced upon fermentation by the mutant strain, to a maximum production level of 21.5 g/l, with a productivity of 0.93 g/l/h. Ethanol production level was further improved to 25.0 g/l upon overexpression of Zymomonas mobilis pdc and adhII genes encoding pyruvate decarboxylase (Pdc) and aldehyde dehydrogenase (Adh), respectively in the mutant strain GEM167. PMID:21186120

  1. Mutant E. coli strain with increased succinic acid production

    DOEpatents

    Donnelly, Mark; Millard, Cynthia S.; Stols, Lucy

    2002-01-01

    A method for isolating succinic acid producing bacteria is provided comprising increasing the biomass of an organism which lacks the ability to catabolize pyruvate, and then subjecting the biomass to glucose-rich medium in an anaerobic environment to enable pyruvate-catabolizing mutants to grow. The invention also provides for a mutant that produces high amounts of succinic acid, which has been derived from a parent which lacked the genes for pyruvate formate lyase and lactate dehydrogenase, and which belongs to the E.coli Group of Bacteria.

  2. Mutant E. coli strain with increased succinic acid production

    DOEpatents

    Donnelly, M.; Millard, C.S.; Stols, L.

    1998-06-23

    A method for isolating succinic acid producing bacteria is provided comprising increasing the biomass of an organism which lacks the ability to catabolize pyruvate, and then subjecting the biomass to glucose-rich medium in an anaerobic environment to enable pyruvate-catabolizing mutants to grow. The invention also provides for a mutant that produces high amounts of succinic acid, which as been derived from a parent which lacked the genes for pyruvate formate lyase and lactate dehydrogenase, and which belongs to the E.coli Group of Bacteria. 2 figs.

  3. Mutant E. coli strain with increased succinic acid production

    DOEpatents

    Donnelly, Mark; Millard, Cynthia S.; Stols, Lucy

    1998-01-01

    A method for isolating succinic acid producing bacteria is provided comprising increasing the biomass of an organism which lacks the ability to catabolize pyruvate, and then subjecting the biomass to glucose-rich medium in an anaerobic environment to enable pyruvate-catabolizing mutants to grow. The invention also provides for a mutant that produces high amounts of succinic acid, which as been derived from a parent which lacked the genes for pyruvate formate lyase and lactate dehydrogenase, and which belongs to the E.coli Group of Bacteria.

  4. Mutant E. coli strain with increased succinic acid production

    DOEpatents

    Donnelly, Mark; Millard, Cynthia S.; Stols, Lucy

    2001-09-25

    A method for isolating succinic acid producing bacteria is provided comprising increasing the biomass of an organism which lacks the ability to catabolize pyruvate, and then subjecting the biomass to glucose-rich medium in an anaerobic environment to enable pyruvate-catabolizing mutants to grow. The invention also provides for a mutant that produces high amounts of succinic acid, which has been derived from a parent which lacked the genes for pyruvate formate lyase and lactate dehydrogenase, and which belongs to the E.coli Group of Bacteria.

  5. Evaluation in mice of Brucella ovis attenuated mutants for use as live vaccines against B. ovis infection.

    PubMed

    Sancho, Pilar; Tejedor, Carmen; Sidhu-Muñoz, Rebeca S; Fernández-Lago, Luis; Vizcaíno, Nieves

    2014-01-01

    Brucella ovis causes ram contagious epididymitis, a disease for which a specific vaccine is lacking. Attenuated Brucella melitensis Rev 1, used as vaccine against ovine and caprine brucellosis caused by B. melitensis, is also considered the best vaccine available for the prophylaxis of B. ovis infection, but its use for this purpose has serious drawbacks. In this work, two previously characterized B. ovis attenuated mutants (Δomp25d and Δomp22) were evaluated in mice, in comparison with B. melitensis Rev 1, as vaccines against B. ovis. Similarities, but also significant differences, were found regarding the immune response induced by the three vaccines. Mice vaccinated with the B. ovis mutants developed anti-B. ovis antibodies in serum of the IgG1, IgG2a and IgG2b subclasses and their levels were higher than those observed in Rev 1-vaccinated mice. After an antigen stimulus with B. ovis cells, splenocytes obtained from all vaccinated mice secreted similar levels of TNF-α and IL12(p40) and remarkably high amounts of IFN-γ, a crucial cytokine in protective immunity against other Brucella species. By contrast, IL-1α -an enhancer of T cell responses to antigen- was present at higher levels in mice vaccinated with the B. ovis mutants, while IL-10, an anti-inflammatory cytokine, was significantly more abundant in Rev 1-vaccinated mice. Additionally, the B. ovis mutants showed appropriate persistence, limited splenomegaly and protective efficacy against B. ovis similar to that observed with B. melitensis Rev 1. These characteristics encourage their evaluation in the natural host as homologous vaccines for the specific prophylaxis of B. ovis infection. PMID:24898325

  6. Evaluation in mice of Brucella ovis attenuated mutants for use as live vaccines against B. ovis infection

    PubMed Central

    2014-01-01

    Brucella ovis causes ram contagious epididymitis, a disease for which a specific vaccine is lacking. Attenuated Brucella melitensis Rev 1, used as vaccine against ovine and caprine brucellosis caused by B. melitensis, is also considered the best vaccine available for the prophylaxis of B. ovis infection, but its use for this purpose has serious drawbacks. In this work, two previously characterized B. ovis attenuated mutants (Δomp25d and Δomp22) were evaluated in mice, in comparison with B. melitensis Rev 1, as vaccines against B. ovis. Similarities, but also significant differences, were found regarding the immune response induced by the three vaccines. Mice vaccinated with the B. ovis mutants developed anti-B. ovis antibodies in serum of the IgG1, IgG2a and IgG2b subclasses and their levels were higher than those observed in Rev 1-vaccinated mice. After an antigen stimulus with B. ovis cells, splenocytes obtained from all vaccinated mice secreted similar levels of TNF-α and IL12(p40) and remarkably high amounts of IFN-γ, a crucial cytokine in protective immunity against other Brucella species. By contrast, IL-1α -an enhancer of T cell responses to antigen- was present at higher levels in mice vaccinated with the B. ovis mutants, while IL-10, an anti-inflammatory cytokine, was significantly more abundant in Rev 1-vaccinated mice. Additionally, the B. ovis mutants showed appropriate persistence, limited splenomegaly and protective efficacy against B. ovis similar to that observed with B. melitensis Rev 1. These characteristics encourage their evaluation in the natural host as homologous vaccines for the specific prophylaxis of B. ovis infection. PMID:24898325

  7. Evaluation of the Salmonella enterica Serovar Pullorum Pathogenicity Island 2 Mutant as a Candidate Live Attenuated Oral Vaccine

    PubMed Central

    Yin, Junlei; Cheng, Zhao; Wang, Xiaochun; Xu, Lijuan; Li, Qiuchun; Geng, Shizhong

    2015-01-01

    Salmonella enterica serovar Pullorum (S. Pullorum) is a highly adapted pathogen that causes pullorum disease (PD), an important systemic disease of poultry that causes severe economic losses in developing countries. In the interests of developing a safe and immunogenic oral vaccine, the efficacy of a Salmonella pathogenicity island 2 (SPI2)-deleted mutant of S. Pullorum (S06004ΔSPI2) was evaluated in chickens. S06004ΔSPI2 was severely less virulent than the parental wild-type strain S06004 as determined by the 50% lethal dose (LD50) for 3-day-old chickens when injected intramuscularly. Two-day-old chickens immunized with a single oral dose of S06004ΔSPI2 showed no differences in body weight or clinical symptoms compared with those in the negative-control group. S06004ΔSPI2 bacteria were not isolated from livers or spleens of immunized chickens after a short period of time, and specific humoral and cellular immune responses were significantly induced. Immunized chickens were challenged with S. Pullorum strain S06004 and Salmonella enterica serovar Gallinarum (S. Gallinarum) strain SG9 at 10 days postimmunization (dpi), and efficient protection against the challenges was observed. None of the immunized chickens died, the clinical symptoms were slight and temporary following challenge in immunized chickens compared with those in the control group, and these chickens recovered by 3 to 5 dpi. Overall, these results demonstrate that S06004ΔSPI2 can be used as a live attenuated oral vaccine. PMID:25924763

  8. Evaluation of the Salmonella enterica Serovar Pullorum Pathogenicity Island 2 Mutant as a Candidate Live Attenuated Oral Vaccine.

    PubMed

    Yin, Junlei; Cheng, Zhao; Wang, Xiaochun; Xu, Lijuan; Li, Qiuchun; Geng, Shizhong; Jiao, Xinan

    2015-07-01

    Salmonella enterica serovar Pullorum (S. Pullorum) is a highly adapted pathogen that causes pullorum disease (PD), an important systemic disease of poultry that causes severe economic losses in developing countries. In the interests of developing a safe and immunogenic oral vaccine, the efficacy of a Salmonella pathogenicity island 2 (SPI2)-deleted mutant of S. Pullorum (S06004ΔSPI2) was evaluated in chickens. S06004ΔSPI2 was severely less virulent than the parental wild-type strain S06004 as determined by the 50% lethal dose (LD50) for 3-day-old chickens when injected intramuscularly. Two-day-old chickens immunized with a single oral dose of S06004ΔSPI2 showed no differences in body weight or clinical symptoms compared with those in the negative-control group. S06004ΔSPI2 bacteria were not isolated from livers or spleens of immunized chickens after a short period of time, and specific humoral and cellular immune responses were significantly induced. Immunized chickens were challenged with S. Pullorum strain S06004 and Salmonella enterica serovar Gallinarum (S. Gallinarum) strain SG9 at 10 days postimmunization (dpi), and efficient protection against the challenges was observed. None of the immunized chickens died, the clinical symptoms were slight and temporary following challenge in immunized chickens compared with those in the control group, and these chickens recovered by 3 to 5 dpi. Overall, these results demonstrate that S06004ΔSPI2 can be used as a live attenuated oral vaccine. PMID:25924763

  9. The role of rpoS, hmp, and ssrAB in Salmonella enterica Gallinarum and evaluation of a triple-deletion mutant as a live vaccine candidate in Lohmann layer chickens

    PubMed Central

    Cho, Youngjae; Park, Yoon Mee; Barate, Abhijit Kashinath; Park, So-Yeon; Park, Hee Jeong; Lee, Mi Rae; Truong, Quang Lam; Yoon, Jang Won

    2015-01-01

    Salmonella enterica Gallinarum (SG) causes fowl typhoid (FT), a septicemic disease in avian species. We constructed deletion mutants lacking the stress sigma factor RpoS, the nitric oxide (NO)-detoxifying flavohemoglobin Hmp, and the SsrA/SsrB regulator to confirm the functions of these factors in SG. All gene products were fully functional in wild-type (WT) SG whereas mutants harboring single mutations or a combination of rpoS, hmp, and ssrAB mutations showed hypersusceptibility to H2O2, loss of NO metabolism, and absence of Salmonella pathogenicity island (SPI)-2 expression, respectively. A triple-deletion mutant, SGΔ3 (SGΔrpoSΔhmpΔssrAB), was evaluated for attenuated virulence and protection efficacy in two-week-old Lohmann layer chickens. The SGΔ3 mutant did not cause any mortality after inoculation with either 1 × 106 or 1 × 108 colony-forming units (CFUs) of bacteria. Significantly lower numbers of salmonellae were recovered from the liver and spleen of chickens inoculated with the SGΔ3 mutant compared to chickens inoculated with WT SG. Vaccination with the SGΔ3 mutant conferred complete protection against challenge with virulent SG on the chickens comparable to the group vaccinated with a conventional vaccine strain, SG9R. Overall, these results indicate that SGΔ3 could be a promising candidate for a live Salmonella vaccine against FT. PMID:25549217

  10. Borrelia burgdorferi Escape Mutants That Survive in the Presence of Antiserum to the OspA Vaccine Are Killed When Complement Is Also Present

    PubMed Central

    Solé, Mónica; Bantar, Carlos; Indest, Karl; Gu, Yan; Ramamoorthy, Ramesh; Coughlin, Richard; Philipp, Mario T.

    1998-01-01

    As an initial attempt to investigate the possible role of outer surface protein A (OspA) escape mutants of Borrelia burgdorferi in decreasing the efficacy of the OspA vaccine, mutants of the HB19 strain of B. burgdorferi sensu stricto were selected in vitro from an uncloned, low-passage-number isolate. The antiserum used for selection was obtained from rhesus monkeys that had been given a vaccine of the same formulation and dose, and by the same route of administration, as that given to humans in several trials. All of the mutants selected in liquid medium and subsequently cloned twice in solid medium expressed a single abundant protein of 28 to 34 kDa instead of both OspA and OspB. Depending on the mutant, this protein reacted strongly, weakly, or not detectably with the anti-OspA antibody used for selection. Analysis of the ospAB locus of each of four representatives from these three groups of mutants by PCR with oligonucleotide primers that hybridize to flanking regions of the ospAB operon, and of the corresponding phenotype with monoclonal antibodies that bind to the amino or carboxyl terminus of the OspA or OspB polypeptide, indicated that in all cases a deletion within the operon had occurred. Spirochetes from the four mutant strains chosen for further analysis could be killed in antibody-dependent, complement-mediated killing assays with the selecting anti-OspA antibody, despite their resistance to killing with this antibody in the absence of complement. Complement-mediated killing occurred at an antibody concentration higher than that required to kill wild-type spirochetes. If anti-OspA antibody acts only within the tick, where complement is probably ineffective due to tick-derived decomplementing factors, then OspA escape mutants, if infectious, could seriously diminish the efficacy of OspA vaccines. On the other hand, if the killing of B. burgdorferi with anti-OspA antibody also takes place within the human host, then our results indicate that chimeric

  11. Experimental study of a further attenuated live measles vaccine of the Sugiyama strain in Iran

    PubMed Central

    Mirchamsy, H.; Shafyi, A.; Rafyi, M. R.; Bahrami, S.; Nazari, P.; Fatemie, S.

    1974-01-01

    After encouraging results of the mass vaccination programme in Iran, in which 5 million children in rural areas were vaccinated with the Japanese Sugiyama strain at its 82nd passage in baby calf kidney, and a progressive decrease in the incidence of measles as well as a reduction of excessive infant mortality, a further attenuated vaccine, produced with the same strain, cloned in Japan, was compared in a field trial with the parent vaccine. The new strain caused fewer reactions than the original strain. Seroconversion with a geometric mean antibody titre of 6·1 was observed in 95% of susceptible children. PMID:4522721

  12. A Web-Based Platform for Designing Vaccines against Existing and Emerging Strains of Mycobacterium tuberculosis

    PubMed Central

    Dhanda, Sandeep Kumar; Vir, Pooja; Singla, Deepak; Gupta, Sudheer; Kumar, Shailesh

    2016-01-01

    Development of an effective vaccine against drug-resistant Mycobacterium tuberculosis (Mtb) is crucial for saving millions of premature deaths every year due to tuberculosis. This paper describes a web portal developed for assisting researchers in designing vaccines against emerging Mtb strains using traditional and modern approaches. Firstly, we annotated 59 genomes of Mycobacterium species to understand similarity/dissimilarity between tuberculoid, non-tuberculoid and vaccine strains at genome level. Secondly, antigen-based vaccine candidates have been predicted in each Mtb strain. Thirdly, epitopes-based vaccine candidates were predicted/discovered in above antigen-based vaccine candidates that can stimulate all arms of immune system. Finally, a database of predicted vaccine candidates at epitopes as well at antigen level has been developed for above strains. In order to design vaccine against a newly sequenced genome of Mtb strain, server integrates three modules for identification of strain-, antigen-, epitope-specific vaccine candidates. We observed that 103522 unique peptides (9mers) had the potential to induce an antibody response and/or promiscuous binder to MHC alleles and/or have the capability to stimulate T lymphocytes. In summary, this web-portal will be useful for researchers working on designing vaccines against Mtb including drug-resistant strains. Availability: The database is available freely at http://crdd.osdd.net/raghava/mtbveb/. PMID:27096425

  13. Complete Genome Sequences of Five Bluetongue Virus (BTV) Vaccine Strains from a Commercial Live Attenuated Vaccine, a BTV-4 Field Strain from South Africa, and a Reassortant Strain Isolated from Experimentally Vaccinated Cattle

    PubMed Central

    Coetzee, Peter; le Grange, Misha; Venter, Estelle H.

    2016-01-01

    This is a report of the complete genome sequences of plaque-selected isolates of each of the five virus strains included in a South African commercial trivalent bluetongue virus (BTV) attenuated live virus vaccine, a BTV-4 field strain isolated from Rustenburg, South Africa, in 2011, and a bluetongue reassortant (bluetongue virus 4 strain 4/O. aries-tc/ZAF/11/OBP-115) isolated from experimentally vaccinated cattle. Full-genome sequencing and phylogenetic analyses show that the bluetongue virus 9 strain 9/B. taurus-tc/ZAF/15/Onderstepoort_B02b is a reassortant virus containing segments from both BTV-9 and BTV-8. PMID:27340051

  14. Characterization of a non-pigment producing Monascus purpureus mutant strain.

    PubMed

    Rasheva, Tanya V; Nedeva, Trayana S; Hallet, Jean-Noel; Kujumdzieva, Anna V

    2003-01-01

    A characterization of a non-pigment producing mutant Monascus purpureus M12 compared with its parental strain Monascus purpureus Went CBS 109.07 has been performed aiming to investigate the relation between pigment biosynthesis and other characteristics of these fungi. A comparison has been made of morphological features, some physiological properties and biochemical activities of both strains. The albino mutant exhibits an anamorph life cycle, high conidia forming capability, slower radial growth rate and temperature sensitivity. The assimilation capacity of both strains for mono-, disaccharides and some alcohols is in the same range (Yx/c 0.2 - 0.35), while the red strain has a higher fermentation capacity. In a selected albino mutant, the growth rate, metabolic activity and capacity for production of typical for Monascus fungi secondary metabolites were reduced considerably. Hydrolytic activity towards natural substrates expressed through glucoamylase and protease was approximately 10 fold lower in the non pigment producing strain (0.05 - 0.08 U/mg protein and 0.01 - 0.07 U/mg protein respectively) compared with the red one. Important qualitative differences between both strains was found in fatty acid composition and in the production of citrinin and monacolin. The mutant strain possessed C17, C20 and C22 fatty acids and did not produce citrinin. PMID:12777069

  15. Transcriptional profiling of recall responses to Francisella live vaccine strain.

    PubMed

    Paranavitana, Chrysanthi; DaSilva, Luis; Vladimirova, Antoaneta; Pittman, Phillip R; Velauthapillai, Mahendran; Nikolich, Mikeljon

    2014-03-01

    Global gene expression profile changes were monitored in human peripheral blood mononuclear cells (PBMCs) after challenge with the live vaccine strain (LVS) of Francisella tularensis. Because these PBMCs were from individuals previously immunized with LVS, stimulating these cells with LVS should activate memory responses. The Ingenuity Pathway Analysis tool identified pathways, functions, and networks associated with this in vitro recall response, including novel pathways triggered by the memory response. Dendritic cell (DC) maturation was the most significant among the more than 25 relevant pathways discovered. Interleukin 15, granulocyte-macrophage colony-stimulating factor, and triggering receptor expressed on myeloid cells 1 signaling pathways were also significant. Pathway analysis indicated that Class 1 antigen presentation may not be optimal with LVS vaccination. The top three biological functions were antigen presentation, cell-mediated and humoral immune responses. Network analysis revealed that the top network associated with these functions had IFNγ and TNFα in central interactive positions. Our results suggest that DC maturation is a key factor in the recall responses and that more effective antigen processing and presentation is needed for cytotoxic T lymphocyte responses. Taken together, these considerations are critical for future tularemia vaccine development studies. PMID:24453125

  16. Biological methods for archiving and maintaining mutant laboratory mice. Part I: conserving mutant strains.

    PubMed

    Fray, Martin D

    2009-01-01

    The mouse is now firmly established as the model organism of choice for scientists studying mammalian biology and human disease. Consequently, a plethora of novel, genetically altered (GA) mouse lines have been created. In addition, the output from the large scale mutagenesis programmes currently under way around the world will increase the collection of GA mouse strains still further. Because of the implications for animal welfare and the constraints on resources, it would be unreasonable to expect anything other than those strains essential for ongoing research programmes to be maintained as breeding colonies. Unfortunately, unless the redundant strains are preserved using robust procedures, which guarantee their recovery, they will be lost to future generations of researchers.This chapter describes some of the preservation methods currently used in laboratories around the world to archive novel mouse strains. PMID:19504080

  17. 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. PMID:24712158

  18. Isolation of rifampicin resistant Flavobacterium psychrophilum strains and their potential as live attenuated vaccine candidates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous studies have demonstrated that passage of pathogenic bacteria on increasing concentrations of the antibiotic rifampicin leads to the attenuation of virulence and these resistant strains may serve as live attenuated vaccines. Two rifampicin resistant strains of Flavobacterium psychrophilum,...

  19. Effects of a Mutant Strain and a Wild Type Strain of Verticillium lecanii on Heterodera glycines Populations in the Greenhouse

    PubMed Central

    Meyer, Susan L. F.; Meyer, Robert J.

    1995-01-01

    A wild type strain ofVerticillium lecanii and a mutant strain with increased tolerance to the fungicide benomyl were evaluated in greenhouse experiments for effects on Heterodera glycines populations. Nematodes were applied at 300 eggs and juveniles per 4,550-cm³ pot (two soybean plants in 4,990 g loamy sand per pot) and at both 300 and 10,000 eggs and juveniles per 1,720-cm³ pot (one soybean plant in 2,060 g sand per pot). With 300 nematodes added per pot, both V. lecanii strains significantly reduced nematode populations in loamy sand (fungus applied at 0.02% dry weight per dry weight loamy sand) and sand (0.006% and 0.06% fungus application rates). The mutant strain applied at 0.002% to sand also significantly reduced cyst numbers. When 10,000 nematodes were added per pot, only the mutant strain at 0.06% significantly decreased population. Various media were tested for isolation of the fungus strains from prills, loamy sand, and sand, but the fungi were recovered from few of the greenhouse pots. PMID:19277306

  20. Permissive growth of human adenovirus type 4 vaccine strain-based vector in porcine cell lines.

    PubMed

    Gao, Dong-Sheng; Li, Xiao-Jing; Wan, Wen-Yan; Li, Hong-Jie; Wang, Xiao-Xue; Yang, Xia; Li, Yong-Tao; Chang, Hong-Tao; Chen, Lu; Wang, Chuan-Qing; Zhao, Jun

    2016-02-01

    In recent years, there has been considerable interest in using adenoviruses as live vectors to develop recombinant vaccines. Previous studies have demonstrated the safety and effectiveness of HIV/SIV and influenza vaccine candidates based on human adenovirus type 4 (Ad4) replication-competent vectors in rhesus macaque and human model. To explore the possibility of human Ad4 vaccine strain used as a vector in developing porcine vaccines, the growth properties of replication-competent human Ad4 vaccine strain recombinant encoding EGFP in different porcine cell lines were investigated. All tested cell lines are permissive for Ad4 vaccine strain vector with varied replication efficiency. Thus, human Ad4 based vectors would be promising supplement to adenovirus vectors as a delivery vehicle for recombinant vaccines in swine industry. PMID:26850542

  1. [Generation of nalidixic acid-resistant strains and signature-tagged mutants of Actinobacillus pleuropneumoniae].

    PubMed

    Shang, Lin; Li, Wei; Li, Liangjun; Li, Lu; Zhang, Sihua; Li, Tingting; Li, Yaokun; Liu, Lei; Guo, Zhiwei; Zhou, Rui; Chen, Huanchun

    2008-01-01

    Actinobacillus pleuropneumoniae is a very important respiratory pathogen for swine and causes great economic losses in pig industry worldwide. Signature-tagged mutagenesis (STM) is an effective method to identify virulence genes in bacteria. In this study, we selected nalidixic acid-resistant strains of APP serotypes 1 and 3 by in vitro cultivation, and used as receipt strains for constructing transposon mutants by mating with E. coli CC 118 lambdapir or S17-1 lambdapir containing mini-Tn10 tag plasmids pLOF/TAG1-48, with or without the help of E. coli DH5alpha (pRK2073). We screened mutant strains by antibiotics selection, PCR and Southern blot identification. Our data revealed that nalidixic acid-resistance of APP strains could easily be induced in vitro and the resistance was due to the mutation in the DNA gyrase A subunit gene gyrA. In the mating experiments, the bi-parental mating was more effective and easier than tri-parental mating. Different APP strains showed a different mating and transposon efficiency in the bi-parental mating, with the strains of serotype 1 much higher than serotype 3 and the reference strain of serotype 3 higher than the field strains. These data were helpful for the construction of STM mutants and pickup of virulence genes of APP. PMID:18338580

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

    PubMed Central

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

    2015-01-01

    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. PMID:26440913

  3. Salmonella abortusovis, strain Rv6, a new vaccinal vehicle for small ruminants.

    PubMed

    Bourgogne, A; Sanchis, R; Clément, J M; Pépin, M

    1998-03-31

    Salmonella abortusovis strain Rv6 (Sao Rv6) is a live attenuated vaccine used for a few years to protect ewes against abortive salmonellosis. As Salmonellae, particularly Salmonella aro mutants, have considerable potential as vehicles for the presentation of heterologous vaccine antigens, Sao Rv6 was tested in order to develop a vaccinal vehicle for small ruminants. Five vector plasmids were tested in Sao Rv6; these plasmids, which carry Maltose Binding Protein (MBP) expressed as protein, but differ in their promotors, had been previously tested in S. typhimurium strain SL3261, and were transferred into Sao Rv6. The five plasmids were stable in vitro, and the recombinant Sao Rv6 expressed MBP at various levels. Intraperitoneal infection of OF1 mice with the recombinant bacteria did not modify the characteristics of Sao Rv6; dissemination and infection levels were similar in all groups and all mice developed antibodies to Salmonella antigens as measured by ELISA. In contrast, only animals immunized with Sao Rv6 carrying the pNTE plasmid developed a serum antibody response to MBP. This plasmid was then tested in sheep; following subcutaneous immunization with Sao Rv6-pNTE, dissemination and infection levels were not modified in comparison with sheep immunized with Sao Rv6 lacking plasmid. Antibodies specific to MBP were detected in sera of sheep immunized with Sao Rv6-pNTE, purified MBP, and with S. typhimurium SL3261-pNTE as positive controls. These results demonstrate that Sao Rv6 can be used as a vehicle for heterologous antigens in sheep with pNTE as plasmid vector. PMID:9631532

  4. Classical swine fever virus Strain 'C'. How long is it detectable after oral vaccination?

    PubMed

    Kaden, V; Lange, E; Riebe, R; Lange, B

    2004-08-01

    To determine the persistence period of C-strain vaccine virus in immunized animals, domestic pigs and wild boars were vaccinated orally and killed on different days post vaccinationem (dpv). Tissue samples were taken at necropsy from both species for detection of C-strain virus. From domestic pigs nasal swabs and faeces were also collected. During the investigation period (2-12 dpv) vaccine virus could never be detected in nasal secretions and in faeces of vaccinated domestic pigs. In contrast, C-strain virus was found in organs until day 8 pv in domestic pigs and until day 9 pv in wild boars. Whereas in domestic pigs virus was detected in tonsils, Ln. mandibularis or in spleen, in wild boar it only was found in tonsils. We conclude that C-strain vaccine virus is not detectable in wild boars longer than 10-12 days after intake of the vaccine baits. PMID:15458487

  5. 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

  6. 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. PMID:24396177

  7. Assessment of inactivated human rabies vaccines: biochemical characterization and genetic identification of virus strains.

    PubMed

    Finke, Stefan; Karger, Axel; Freuling, Conrad; Müller, Thomas

    2012-05-21

    The World Health Organization (WHO) recommends the periodic evaluation of the purity of the cell lines used in the production of rabies vaccines, as well as the antigenic identity of the virus strains. Here, we analyzed seventeen marketed inactivated human rabies virus vaccines for viral and non-viral proteins by SDS-PAGE and Coomassie/silver staining. Mass spectrometric analysis of an abundant 60-70 kDa signal indicated that in most vaccines serum albumin of human origin (HSA) was the major component. Quantification of HSA in the vaccines revealed a mean concentration of 22 mg HSA/dose in all tested PVRV (purified vero cell rabies vaccine), HDCV (human diploid cell rabies vaccine) and PHK (primary hamster kidney) vaccines. In contrast, 1000-fold lower HSA levels and no HSA were detected in PCECV (purified chick embryo cell-culture vaccine) and PDEV (duck embryo rabies vaccine), respectively. Western blot analyses further confirmed a high bias in the HSA content, whereas the virus protein levels were rather similar in all tested vaccines. In addition, the vaccine viruses were sequenced within the N- and G-genes to identify the strain. In the majority of sequenced vaccines, the declared vaccine strain was confirmed. However, some discrepancies in the genetic identification were observed, supporting WHO's recommendation for the molecular characterization of vaccine seed strains. This research highlights the variation in purity found between different human rabies virus vaccines, and suggests that further research is needed to establish the impact non-active components have on the potency of such vaccines. PMID:22469862

  8. Comparative Full Length Sequence Analysis of Oncogenic and Vaccine (Rispens) Strains of Marek's Disease Virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The complete DNA sequence of the Marek’s disease virus serotype 1 vaccine strain CVI988 was determined and consists of 178,311 bp with an overall gene organization identical to that of the oncogenic strains. In examining open reading frames (ORFs), nine ORFs differ between vaccine and oncogenic stra...

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

    PubMed

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

    2016-02-01

    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

  10. 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

  11. Effect of polymyxin B and environmental conditions on isolation of Brucella species and the vaccine strain RB51.

    PubMed

    Jensen, Allen E; Halling, Shirley M

    2010-03-01

    Brucella are resistant to polymyxin B (PB), but their relative susceptibility to PB and its derivative, colistin (COL) has not been rigorously or systematically studied. Comparative susceptibility of Brucella reference strains, vaccine strain RB51, and Brucella isolates from marine mammals to these two cationic peptides were determined by Etest. Vast differences among Brucella species were found in susceptibility to both PB and COL. Brucella demonstrated similar pattern of relative susceptibility to PB as that of COL, but they were less susceptible to COL. Both B. melitensis and B. suis were the least susceptible to polymyxins and rough strains were more susceptible to both PB and COL than the smooth except for the BvrR mutant. Strains were generally less susceptible to PB when cultured in CO(2) rather than ambient air; some became more susceptible in acidified medium. Results show that environment cultural conditions must be considered when selecting for CO(2)-independent strains of Brucella especially the vaccine strain RB51 on selective media containing PB. Our observations extend basic knowledge of the differential resistance of Brucella to polymyxins. PMID:18814911

  12. Genetic stability of vaccine strain Salmonella Typhi Ty21a over 25 years.

    PubMed

    Kopecko, Dennis J; Sieber, Heike; Ures, Jose A; Fürer, Andreas; Schlup, Jacqueline; Knof, Ulrich; Collioud, Andre; Xu, Deqi; Colburn, Kevin; Dietrich, Guido

    2009-04-01

    The attenuated live bacterial vaccine strain Salmonella enterica Serovar Typhi Ty21a is the main constituent of Vivotif, the only licensed oral vaccine against typhoid fever. The strain was developed in the 1970s by chemical mutagenesis. In the course of this mutagenesis, a number of mutations were introduced into the vaccine strain. Characterisation of the vaccine strain during development as well as release of master- and working seed lots (MSL and WSL) and commercial batches is based on phenotypic assays assessing microbiological and biochemical characteristics of Ty21a. In the current study, we have analysed by DNA sequencing the specific mutations originally correlated with the attenuation of strain Ty21a. These data demonstrate the stability of these mutations for MSLs and WSLs of Ty21a produced between 1980 and 2005. Finally, we have confirmed the correlation of these genetic mutations with the expected phenotypic attenuations for the seed lots used in vaccine manufacture over 25 years. PMID:19121604

  13. The serological response of young dogs to the Flury LEP strain of rabies virus vaccine.

    PubMed

    Aghomo, H O; Oduye, O O; Rupprecht, C E

    1990-01-01

    The serological response of puppies from Nigeria to live Flury low egg passage (LEP) rabies vaccine was determined. Two sets of puppies were used: one set from rabies-vaccinated bitches and another set from non-vaccinated bitches. Puppies were vaccinated intramuscularly with Flury LEP strain rabies vaccine and serially bled from the 4th week to the 30th week. Serum rabies virus neutralizing antibodies (VNA) were measured by a modified rapid fluorescent focus inhibition test (RFFIT). Puppies from non-vaccinated bitches responded well to vaccination after the 4th week and through to the 10th week of age, showing a progressive increase in VNA. In contrast, puppies from vaccinated bitches responded well to rabies vaccination only at 10 weeks of age, although detectable maternal rabies VNA and rabies anti-ribonucleoprotein (RNP) antibodies had decreased by 6 weeks post partum. PMID:2247948

  14. Global carbon utilization profiles of wild-type, mutant, and transformant strains of Hypocrea jecorina.

    PubMed

    Druzhinina, Irina S; Schmoll, Monika; Seiboth, Bernhard; Kubicek, Christian P

    2006-03-01

    The ascomycete Hypocrea jecorina (Trichoderma reesei), an industrial producer of cellulases and hemicellulases, can efficiently degrade plant polysaccharides. However, the catabolic pathways for the resulting monomers and their relationship to enzyme induction are not well known. Here we used the Biolog Phenotype MicroArrays technique to evaluate the growth of H. jecorina on 95 carbon sources. For this purpose, we compared several wild-type isolates, mutants producing different amounts of cellulases, and strains transformed with a heterologous antibiotic resistance marker gene. The wild-type isolates and transformed strains had the highest variation in growth patterns on individual carbon sources. The cellulase mutants were relatively similar to their parental strains. Both in the mutant and in the transformed strains, the most significant changes occurred in utilization of xylitol, erythritol, D-sorbitol, D-ribose, D-galactose, L-arabinose, N-acetyl-D-glucosamine, maltotriose, and beta-methyl-glucoside. Increased production of cellulases was negatively correlated with the ability to grow on gamma-aminobutyrate, adonitol, and 2-ketogluconate; and positively correlated with that on d-sorbitol and saccharic acid. The reproducibility, relative simplicity, and high resolution (+/-10% of increase in mycelial density) of the phenotypic microarrays make them a useful tool for the characterization of mutant and transformed strains and for a global analysis of gene function. PMID:16517662

  15. Bovine herpesvirus-1: comparison and differentiation of vaccine and field strains based on genomic sequence variation.

    PubMed

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

    2013-03-01

    Bovine herpesvirus-1 (BoHV-1) causes significant disease in cattle including respiratory, fetal diseases, and reproductive tract infections. Control programs usually include vaccination with a modified live viral (MLV) vaccine. On occasion BoHV-1 strains are isolated from diseased animals or fetuses postvaccination. Currently there are no markers for differentiating MLV strains from field strains of BoHV-1. In this study several BoHV-1 strains were sequenced using whole-genome sequencing technologies and the data analyzed to identify single nucleotide polymorphisms (SNPs). Strains sequenced included the reference BoHV-1 Cooper strain (GenBank Accession JX898220), eight commercial MLV vaccine strains, and 14 field strains from cases presented for diagnosis. Based on SNP analyses, the viruses could be classified into groups having similar SNP patterns. The eight MLV strains could be differentiated from one another although some were closely related to each other. A number of field strains isolated from animals with a history of prior vaccination had SNP patterns similar to specific MLV viruses, while other field isolates were very distinct from all vaccine strains. The results indicate that some BoHV-1 isolates from clinically ill cattle/fetuses can be associated with a prior MLV vaccination history, but more information is needed on the rate of BoHV-1 genome sequence change before irrefutable associations can be drawn. PMID:23333211

  16. Construction of an attenuated Salmonella enterica serovar Paratyphi A vaccine strain harboring defined mutations in htrA and yncD.

    PubMed

    Zhu, Chunyue; Xiong, Kun; Chen, Zhijin; Hu, Xiaomei; Li, Jianhua; Wang, Yiran; Rao, Xiancai; Cong, Yanguang

    2015-08-01

    The global epidemic features of enteric fever have changed greatly in recent years. The incidence of enteric fever caused by Salmonella enterica serovar Paratyphi A has progressively increased. In some areas of Asia, infections with S. Paratyphi A have exceeded those with S. Typhi, resulting in S. Paratyphi A becoming the main causative agent of enteric fever. However, two currently licensed typhoid vaccines do not confer adequate cross-protection against S. Paratyphi A infection. Therefore, development of specific vaccines against enteric fever caused by S. Paratyphi A is urgently needed. In the present study, an attenuated strain was constructed by double deletion of the htrA and yncD genes in a wild-type strain of S. Paratyphi A and its safety and immunogenicity assessed. In a mouse model, the 50% lethal dose of the double deletion mutant and the wild-type strain were 3.0 × 10(8) CFU and 1.9 × 10(3) CFU, respectively, suggesting that the double deletion resulted in remarkably decreased bacterial virulence. Bacterial colonization of the double deletion mutant in the livers and spleens of infected mice was strikingly less than that of the wild-type strain. A single nasal administration of the attenuated vaccine candidate elicited high concentrations of anti-LPS and anti-flagellin IgG in a mouse model and protected immunized mice against lethal challenge with the wild-type strain. Thus, our findings suggest that the attenuated vaccine strain is a promising candidate worthy of further evaluation both as a human enteric fever vaccine and as a vaccine delivery vector for heterologous antigens. PMID:26084199

  17. Selection and Characterization of Phage-Resistant Mutant Strains of Listeria monocytogenes Reveal Host Genes Linked to Phage Adsorption

    PubMed Central

    Denes, Thomas; den Bakker, Henk C.; Tokman, Jeffrey I.; Guldimann, Claudia

    2015-01-01

    Listeria-infecting phages are readily isolated from Listeria-containing environments, yet little is known about the selective forces they exert on their host. Here, we identified that two virulent phages, LP-048 and LP-125, adsorb to the surface of Listeria monocytogenes strain 10403S through different mechanisms. We isolated and sequenced, using whole-genome sequencing, 69 spontaneous mutant strains of 10403S that were resistant to either one or both phages. Mutations from 56 phage-resistant mutant strains with only a single mutation mapped to 10 genes representing five loci on the 10403S chromosome. An additional 12 mutant strains showed two mutations, and one mutant strain showed three mutations. Two of the loci, containing seven of the genes, accumulated the majority (n = 64) of the mutations. A representative mutant strain for each of the 10 genes was shown to resist phage infection through mechanisms of adsorption inhibition. Complementation of mutant strains with the associated wild-type allele was able to rescue phage susceptibility for 6 out of the 10 representative mutant strains. Wheat germ agglutinin, which specifically binds to N-acetylglucosamine, bound to 10403S and mutant strains resistant to LP-048 but did not bind to mutant strains resistant to only LP-125. We conclude that mutant strains resistant to only LP-125 lack terminal N-acetylglucosamine in their wall teichoic acid (WTA), whereas mutant strains resistant to both phages have disruptive mutations in their rhamnose biosynthesis operon but still possess N-acetylglucosamine in their WTA. PMID:25888172

  18. Selection and Characterization of Phage-Resistant Mutant Strains of Listeria monocytogenes Reveal Host Genes Linked to Phage Adsorption.

    PubMed

    Denes, Thomas; den Bakker, Henk C; Tokman, Jeffrey I; Guldimann, Claudia; Wiedmann, Martin

    2015-07-01

    Listeria-infecting phages are readily isolated from Listeria-containing environments, yet little is known about the selective forces they exert on their host. Here, we identified that two virulent phages, LP-048 and LP-125, adsorb to the surface of Listeria monocytogenes strain 10403S through different mechanisms. We isolated and sequenced, using whole-genome sequencing, 69 spontaneous mutant strains of 10403S that were resistant to either one or both phages. Mutations from 56 phage-resistant mutant strains with only a single mutation mapped to 10 genes representing five loci on the 10403S chromosome. An additional 12 mutant strains showed two mutations, and one mutant strain showed three mutations. Two of the loci, containing seven of the genes, accumulated the majority (n = 64) of the mutations. A representative mutant strain for each of the 10 genes was shown to resist phage infection through mechanisms of adsorption inhibition. Complementation of mutant strains with the associated wild-type allele was able to rescue phage susceptibility for 6 out of the 10 representative mutant strains. Wheat germ agglutinin, which specifically binds to N-acetylglucosamine, bound to 10403S and mutant strains resistant to LP-048 but did not bind to mutant strains resistant to only LP-125. We conclude that mutant strains resistant to only LP-125 lack terminal N-acetylglucosamine in their wall teichoic acid (WTA), whereas mutant strains resistant to both phages have disruptive mutations in their rhamnose biosynthesis operon but still possess N-acetylglucosamine in their WTA. PMID:25888172

  19. Genetics of Peripheral Vestibular Dysfunction: Lessons from Mutant Mouse Strains

    PubMed Central

    Jones, Sherri M.; Jones, Timothy A.

    2015-01-01

    Background A considerable amount of research has been published about genetic hearing impairment. Fifty to sixty percent of hearing loss is thought to have a genetic cause. Genes may also play a significant role in acquired hearing loss due to aging, noise exposure, or ototoxic medications. Between 1995 and 2012, over 100 causative genes have been identified for syndromic and nonsyndromic forms of hereditary hearing loss (see Hereditary Hearing Loss Homepage http://hereditaryhearingloss.org). Mouse models have been extremely valuable in facilitating the discovery of hearing loss genes, and in understanding inner ear pathology due to genetic mutations or elucidating fundamental mechanisms of inner ear development. Purpose Whereas much is being learned about hereditary hearing loss and the genetics of cochlear disorders, relatively little is known about the role genes may play in peripheral vestibular impairment. Here we review the literature with regard to genetics of vestibular dysfunction and discuss what we have learned from studies using mutant mouse models and direct measures of peripheral vestibular neural function. Results Several genes are considered that when mutated lead to varying degrees of inner ear vestibular dysfunction due to deficits in otoconia, stereocilia, hair cells, or neurons. Behavior often does not reveal the inner ear deficit. Many of the examples presented are also known to cause human disorders. Conclusions Knowledge regarding the roles of particular genes in the operation of the vestibular sensory apparatus is growing and it is clear that gene products co-expressed in the cochlea and vestibule may play different roles in the respective end organs. The discovery of new genes mediating critical inner ear vestibular function carries the promise of new strategies in diagnosing, treating and managing patients as well as predicting the course and level of morbidity in human vestibular disease. PMID:25032973

  20. Frequency-dependent viability in mutant strains of Drosophila melanogaster.

    PubMed

    Curtsinger, J W; Sheen, F M

    1991-01-01

    We investigated the effects of genotypic frequencies on egg-to-adult viabilities in pairwise combinations of four strains of Drosophila melanogaster. The experiments involved mixture of a total of 42,000 eggs in varying proportions under controlled densities and observation of surviving adults. Viabilities were found to depend on frequencies in several genotypic combinations. In the most extreme case, the absolute viability of cn;bw females increased monotonically from 54% when common to 70% when rare. The results illustrate several statistical and methodological problems that might explain why some experiments have failed to detect frequency-dependent viabilities. These problems include heterogeneity between replications, sex differences in susceptibility to competition, and strong dependence of the experimental outcome on the choice of competitor genotypes. PMID:1901577

  1. Selecting vaccine strains for H3N2 human influenza A virus

    PubMed Central

    Suzuki, Yoshiyuki

    2015-01-01

    H3N2 human influenza A virus causes epidemics of influenza mainly in the winter season in temperate regions. Since the antigenicity of this virus evolves rapidly, several attempts have been made to predict the major amino acid sequence of hemagglutinin 1 (HA1) in the target season of vaccination. However, the usefulness of predicted sequence was unclear because its relationship to the antigenicity was unknown. Here the antigenic model for estimating the degree of antigenic difference (antigenic distance) between amino acid sequences of HA1 was integrated into the process of selecting vaccine strains for H3N2 human influenza A virus. When the effectiveness of a potential vaccine strain for a target season was evaluated retrospectively using the average antigenic distance between the strain and the epidemic viruses sampled in the target season, the most effective vaccine strain was identified mostly in the season one year before the target season (pre-target season). Effectiveness of actual vaccines appeared to be lower than that of the strains randomly chosen in the pre-target season on average. It was recommended to replace the vaccine strain for every target season with the strain having the smallest average antigenic distance to the others in the pre-target season. The procedure of selecting vaccine strains for future epidemic seasons described in the present study was implemented in the influenza virus forecasting system (INFLUCAST) (http://www.nsc.nagoya-cu.ac.jp/~yossuzuk/influcast.html). PMID:25893173

  2. Genome sequence of Bacillus anthracis attenuated vaccine strain A16R used for human in China.

    PubMed

    Liu, Xiankai; Qi, Xinpeng; Zhu, Li; Wang, Dongshu; Gao, Zhiqi; Deng, Haijun; Wu, Weili; Hu, Tao; Chen, Chen; Chen, Weijun; Wang, Hengliang

    2015-09-20

    An attenuated Bacillus anthracis vaccine strain for human use, A16R, was obtained in China after ultraviolet radiation treatment and continuous subculture of the wild-type strain A16. A16R can synthesize the exotoxin, but without a capsule. We sequenced and annotated the A16R genome to encourage the use of this strain. The genome sequencing of the wild-type strain A16 is underway and the genomic comparison between the two strains will help to illustrate the attenuating mechanism of the A16R vaccine strain. PMID:26116813

  3. Derepression of colicin E1 synthesis in the constitutive tif mutant strain (spr tif sfi) and in a tif sfi mutant strain of Escherichia coli K-12.

    PubMed Central

    Tessman, E S; Gritzmacher, C A; Peterson, P K

    1978-01-01

    We show here that expression of the colicin gene of the ColE1 plasmid is greatly derepressed in Escherichia coli K-12 strain DM1187 spr tif sfi, which is a constitutive tif mutant, altered in the lexA gene, and which shows constitutive expression of various pathways of the recA-dependent, lexA-blocked (SOS) repair system. In this strain colicin E1 synthesis is at least 100-fold greater than that observed in uninduced control strains (spr+ tif sfi and spr+ tif+ sfi). This result confirms the regulatory role of the lexA product in colicin E1 synthesis. Colicin yields by the uninduced strain DM1187 are as high as the maximum yields from mitomycin-induced control strains and often are several-fold higher. When the nonconstitutive tif sfi strain GC467 is raised to 43 degrees C to induce the SOS system, a low level of colicin synthesis is observed which is less than one-tenth of the yield obtained by induction with mitomycin C. Addition of adenine at the time of shift-up can increase the colicin yield of tif sfi to about one-third of the yield obtained with mitomycin C. We have also found that colicin overproduction can be detected by altered colony appearance in an overlay assay with colicin-sensitive bacteria. In addition, the lethality of the process of colicin synthesis is observed here without the use of bacteriostatic inducing agents. Images PMID:353034

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  5. Large scale parallel pyrosequencing technology: PRRSV strain VR-2332 nsp2 deletion mutant stability in swine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  6. Effects of vaccination with F-strain Mycoplasma gallisepticum on egg production and quality parameters of commercial layer hens previously vaccinated with 6/85-strain Mycoplasma gallisepticum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An experiment was conducted to determine the effect of overlaying (revaccinating) F strain Mycoplasma gallisepticum (MG) at 22 or 45 weeks of age on commercial leghorn hens previously vaccinated with 6/85 strain MG at 10 weeks of age. The treatment groups include unvaccinated hens (group 1), hens r...

  7. Predicted Strain Coverage of a New Meningococcal Multicomponent Vaccine (4CMenB) in Spain: Analysis of the Differences with Other European Countries

    PubMed Central

    Abad, Raquel; Medina, Verónica; Stella, Maria; Boccadifuoco, Giuseppe; Comanducci, Maurizio; Bambini, Stefania; Muzzi, Alessandro; Vázquez, Julio A.

    2016-01-01

    where the multicomponent vaccine is introduced. This is really important in countries like Spain where most of the strains are predicted to be covered by only one vaccine antigen and the chance for escape mutants to emerge with vaccine use is higher. Based on the observed data, cc213 should receive special attention as it is associated with low predicted strain coverage, and has recently emerged in Spain. PMID:26950303

  8. Vaccination with an Attenuated Mutant of Ehrlichia chaffeensis Induces Pathogen-Specific CD4+ T Cell Immunity and Protection from Tick-Transmitted Wild-Type Challenge in the Canine Host

    PubMed Central

    McGill, Jodi L.; Nair, Arathy D. S.; Cheng, Chuanmin; Rusk, Rachel A.; Jaworski, Deborah C.; Ganta, Roman R.

    2016-01-01

    Ehrlichia chaffeensis is a tick-borne rickettsial pathogen and the causative agent of human monocytic ehrlichiosis. Transmitted by the Amblyomma americanum tick, E. chaffeensis also causes disease in several other vertebrate species including white-tailed deer and dogs. We have recently described the generation of an attenuated mutant strain of E. chaffeensis, with a mutation in the Ech_0660 gene, which is able to confer protection from secondary, intravenous-administered, wild-type E. chaffeensis infection in dogs. Here, we extend our previous results, demonstrating that vaccination with the Ech_0660 mutant protects dogs from physiologic, tick-transmitted, secondary challenge with wild-type E. chaffeensis; and describing, for the first time, the cellular and humoral immune responses induced by Ech_0660 mutant vaccination and wild-type E. chaffeensis infection in the canine host. Both vaccination and infection induced a rise in E. chaffeensis-specific antibody titers and a significant Th1 response in peripheral blood as measured by E. chaffeensis antigen-dependent CD4+ T cell proliferation and IFNγ production. Further, we describe for the first time significant IL-17 production by peripheral blood leukocytes from both Ech_0660 mutant vaccinated animals and control animals infected with wild-type E. chaffeensis, suggesting a previously unrecognized role for IL-17 and Th17 cells in the immune response to rickettsial pathogens. Our results are a critical first step towards defining the role of the immune system in vaccine-induced protection from E. chaffeensis infection in an incidental host; and confirm the potential of the attenuated mutant clone, Ech_0660, to be used as a vaccine candidate for protection against tick-transmitted E. chaffeensis infection. PMID:26841025

  9. [Saccharomyces cerevisiae: porphobilinogenase activity in a wild-type strain and its heme-deficient mutant].

    PubMed

    Araujo, L S; Lombardo, M E; Rossetti, M V; Batlle, A M

    1987-01-01

    Properties of Porphobilinogenase (PBGase), the enzyme complex converting porphobilinogen (PBG) into uroporphyrinogens, were comparatively studied in a wild strain D273-10B and its mutant B231 of Saccharomyces cerevisiae, Figure 1 shows the growth curves for both strains. The basic pattern of growth was observed but, although S. cerevisiae is a facultative aerobe and was grown on dextrose, a diauxic growth curve was not observed. The beginning of the exponential phase was slightly delayed for the mutant, so, its generation time (G = 3.20 h) was greater than that for the wild strain (G = 1.26 h). Optimum conditions for extracting the enzyme from both strains were found to be sonication at 10 mu for 3 min (Table 1). Table 2 shows the effect of centrifugation at 24,000 xg for 30 min on activity. For both strains the amount of porphyrins formed was the same either in the absence or presence of air. It was found (Figure 2) that urogen formation was linear with protein over a wide range of concentrations and with incubation time up to 2h in agreement with previous results for the enzyme of different sources. Figure 3 shows the effect of pH on PBGase activity. An optimum pH of 7.4 was found for both strains employing sodium phosphate buffer pH 8.0. The shape of the pH curve as well as optimum pH were the same in both Tris-HCl and phosphate buffer, however PBGase was 15% less active in the former. When plots of velocity against PBG concentration were analyzed for PBGase, it was found that measuring the rate of the reaction on the basis of total urogen formation, saturation curves for wild and mutant strains harvested at the exponential phase, followed classical Michaelis-Menten kinetics. Saturation was reached at PBG concentration of about 70-90 microM. Therefore, double reciprocal plots (Figure 4) were linear and from these plots apparent Km's values of 20 and 14 microM were obtained for the wild and mutant strain respectively. It is known that in some organisms, the

  10. Mutant strains of Pichia pastoris with enhanced secretion of recombinant proteins.

    PubMed

    Larsen, Sasha; Weaver, Jun; de Sa Campos, Katherine; Bulahan, Rhobe; Nguyen, Jackson; Grove, Heather; Huang, Amy; Low, Lauren; Tran, Namphuong; Gomez, Seth; Yau, Jennifer; Ilustrisimo, Thomas; Kawilarang, Jessica; Lau, Jonathan; Tranphung, Maivi; Chen, Irene; Tran, Christina; Fox, Marcia; Lin-Cereghino, Joan; Lin-Cereghino, Geoff P

    2013-11-01

    Although Pichia pastoris is a popular protein expression system, it exhibits limitations in its ability to secrete heterologous proteins. Therefore, a REMI (restriction enzyme mediated insertion) strategy was utilized to select mutant beta-g alactosidase s upersecretion (bgs) strains that secreted increased levels of a β-galactosidase reporter. Many of the twelve BGS genes may have functions in intracellular signaling or vesicle transport. Several of these strains also appeared to contain a more permeable cell wall. Preliminary characterization of four bgs mutants showed that they differed in the ability to enhance the export of other reporter proteins. bgs13, which has a disruption in a gene homologous to Saccharomyces cerevisiae protein kinase C (PKC1), gave enhanced secretion of most recombinant proteins that were tested, raising the possibility that it has the universal super-secreter phenotype needed in an industrial production strain of P. pastoris. PMID:23881328

  11. Genetic characterisation of attenuated SAD rabies virus strains used for oral vaccination of wildlife.

    PubMed

    Geue, Lutz; Schares, Susann; Schnick, Christina; Kliemt, Jeannette; Beckert, Aline; Freuling, Conrad; Conraths, Franz J; Hoffmann, Bernd; Zanoni, Reto; Marston, Denise; McElhinney, Lorraine; Johnson, Nicholas; Fooks, Anthony R; Tordo, Noel; Müller, Thomas

    2008-06-19

    The elimination of rabies from the red fox (Vulpes vulpes) in Western Europe has been achieved by the oral rabies vaccination (ORV) of wildlife with a range of attenuated rabies virus strains. With the exception of the vaccinia rabies glycoprotein recombinant vaccine (VRG), all strains were originally derived from a common ancestor; the Street Alabama Dufferin (SAD) field strain. However, after more than 30 years of ORV it is still not possible to distinguish these vaccine strains and there is little information on the genetic basis for their attenuation. We therefore sequenced and compared the full-length genome of five commercially available SAD vaccine viruses (SAD B19, SAD P5/88, SAG2, SAD VA1 and SAD Bern) and four other SAD strains (the original SAD Bern, SAD VA1, ERA and SAD 1-3670 Wistar). Nucleotide sequencing allowed identifying each vaccine strain unambiguously. Phylogenetic analysis revealed that the majority of the currently used commercial attenuated rabies virus vaccines appear to be derived from SAD B19 rather than from SAD Bern. One commercially available vaccine virus did not contain the SAD strain mentioned in the product information of the producer. Two SAD vaccine strains appeared to consist of mixed genomic sequences. Furthermore, in-del events targeting A-rich sequences (in positive strand) within the 3' non-coding regions of M and G genes were observed in SAD-derivates developed in Europe. Our data also supports the idea of a possible recombination that had occurred during the derivation of the European branch of SAD viruses. If confirmed, this recombination event would be the first one reported among RABV vaccine strains. PMID:18485548

  12. Optimization and Characterization of Candidate Strain for Coxsackievirus A16 Inactivated Vaccine.

    PubMed

    Li, Jingliang; Liu, Guanchen; Liu, Xin; Yang, Jiaxin; Chang, Junliang; Zhang, Wenyan; Yu, Xiao-Fang

    2015-07-01

    Coxsackievirus A16 (CA16) and enterovirus 71 (EV71), both of which can cause hand, foot and mouth disease (HFMD), are responsible for large epidemics in Asian and Pacific areas. Although inactivated EV71 vaccines have completed testing in phase III clinical trials in Mainland China, CA16 vaccines are still under development. A Vero cell-based inactivated CA16 vaccine was developed by our group. Screening identified a CA16 vaccine strain (CC024) isolated from HFMD patients, which had broad cross-protective abilities and satisfied all requirements for vaccine production. Identification of the biological characteristics showed that the CA16CC024 strain had the highest titer (107.5 CCID50/mL) in Vero cells, which would benefit the development of an EV71/CA16 divalent vaccine. A potential vaccine manufacturing process was established, including the selection of optimal time for virus harvesting, membrane for diafiltration and concentration, gel-filtration chromatography for the down-stream virus purification and virus inactivation method. Altogether, the analyses suggested that the CC-16, a limiting dilution clone of the CC024 strain, with good genetic stability, high titer and broad-spectrum immunogenicity, would be the best candidate strain for a CA16 inactivated vaccine. Therefore, our study provides valuable information for the development of a Vero cell-based CA16 or EV71-CA16 divalent inactivated vaccine. PMID:26193302

  13. Optimization and Characterization of Candidate Strain for Coxsackievirus A16 Inactivated Vaccine

    PubMed Central

    Li, Jingliang; Liu, Guanchen; Liu, Xin; Yang, Jiaxin; Chang, Junliang; Zhang, Wenyan; Yu, Xiao-Fang

    2015-01-01

    Coxsackievirus A16 (CA16) and enterovirus 71 (EV71), both of which can cause hand, foot and mouth disease (HFMD), are responsible for large epidemics in Asian and Pacific areas. Although inactivated EV71 vaccines have completed testing in phase III clinical trials in Mainland China, CA16 vaccines are still under development. A Vero cell-based inactivated CA16 vaccine was developed by our group. Screening identified a CA16 vaccine strain (CC024) isolated from HFMD patients, which had broad cross-protective abilities and satisfied all requirements for vaccine production. Identification of the biological characteristics showed that the CA16CC024 strain had the highest titer (107.5 CCID50/mL) in Vero cells, which would benefit the development of an EV71/CA16 divalent vaccine. A potential vaccine manufacturing process was established, including the selection of optimal time for virus harvesting, membrane for diafiltration and concentration, gel-filtration chromatography for the down-stream virus purification and virus inactivation method. Altogether, the analyses suggested that the CC-16, a limiting dilution clone of the CC024 strain, with good genetic stability, high titer and broad-spectrum immunogenicity, would be the best candidate strain for a CA16 inactivated vaccine. Therefore, our study provides valuable information for the development of a Vero cell-based CA16 or EV71-CA16 divalent inactivated vaccine. PMID:26193302

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

    SciTech Connect

    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. . E-mail: dongj@genphar.com

    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{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.

  15. Characterization of genetically inactivated pertussis toxin mutants: candidates for a new vaccine against whooping cough.

    PubMed Central

    Nencioni, L; Pizza, M; Bugnoli, M; De Magistris, T; Di Tommaso, A; Giovannoni, F; Manetti, R; Marsili, I; Matteucci, G; Nucci, D

    1990-01-01

    the introduction of two amino acid substitutions within the enzymatically active subunit S1 of pertussis toxin (PT) abolishes its ADP-ribosyltransferase activity and toxicity on CHO cells (Pizza et al., Science 246:497-500, 1989). These genetically inactivated molecules are also devoid of other in vivo adverse reactions typical of PT, such as induction of leukocytosis, potentiation of anaphylaxis, stimulation of insulin secretion, and histamine sensitivity. However, the mutant PT molecules are indistinguishable from wild-type PT in sodium dodecyl sulfate-polyacrylamide gel electrophoresis and maintain all the physical and chemical properties of PT, including affinity for toxin-neutralizing poly- and monoclonal antibodies. Either alone or stabilized with formaldehyde, PT mutants are able to induce high levels of neutralizing antibodies and to protect mice in a dose-dependent fashion against intracerebral challenge with virulent B. pertussis. These results clearly show that these genetically inactivated PT molecules are nontoxic but still immunogenic and justify their development as a component of a new, safer acellular vaccine against whooping cough. Images PMID:2323818

  16. Genetic stability of vaccine strains by multilocus sequence typing and pulsed-field gel electrophoresis analysis: Implications for quality control of the leptospiral vaccine

    PubMed Central

    Xu, Yinghua; Zhang, Jinlong; Cui, Shenghui; Li, Min; Zhang, Ying; Xue, Honggang; Xin, Xiaofang; Wang, Junzhi

    2015-01-01

    Quality control of vaccine strains is directly associated with the safety and efficacy of inactivated whole bacterial vaccines. The assessment of genetic stability is one of the essential elements to guarantee the quality of vaccine strains. The multiple-valence inactivated leptospiral vaccine, comprising the main circulating serogroups, has played an important role in the control of Leptospira infection in China. In the present study, to assess the genetic stability of vaccine strains and develop novel quality control tests that enhance and extend the existing procedures, 7 Chinese leptospiral vaccine strains were characterized during in vivo and in vitro passages by multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE) analysis. The seven vaccine strains were found to have distinct sequence types (STs) and PFGE profiles. Further analysis showed that the ST and PFGE pattern of each vaccine strain, after in vivo or serial in vitro passages (up to 20 passages), were identical to those of the initial strain, demonstrating that these strains were genetically stable and homogeneous. Taken together, PFGE and MLST provide a reproducible and reliable means for confirming the identity and genetic stability of vaccine seeds, suggesting that these approaches can be used to evaluate the quality of leptospiral vaccine strains. PMID:25806658

  17. 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. PMID:27013433

  18. Molecular characterization of a novobiocin-resistant Aeromonas hydrophila catfish vaccine strain compared to its virulent parent strain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A total of 10 and 13 missense mutations were found in the deduced gyrB and rpoB proteins, respectively, between avirulent AH11NOVO vaccine strain and its virulent parent strain AH11P. SDS-PAGE revealed that six proteins bands were significantly over-expressed in AH11NOVO whereas five bands were sign...

  19. Molecular characterization of a novobiocin-resistant Aeromonas hydrophila catfish vaccine strain compared to its virulent parent strain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A total of 10 and 13 missense mutations were found in the deduced GyrB and RpoB proteins, respectively, between avirulent AH11NOVO vaccine strain and its virulent parent strain AH11P. SDS-PAGE revealed that six proteins bands were significantly over-expressed in AH11NOVO whereas five bands were sign...

  20. Cell-mediated and humoral immune responses after vaccination of human volunteers with the live vaccine strain of Francisella tularensis.

    PubMed

    Waag, D M; McKee, K T; Sandstrom, G; Pratt, L L; Bolt, C R; England, M J; Nelson, G O; Williams, J C

    1995-03-01

    The specific humoral and cell-mediated immune responses of human volunteers vaccinated with the Francisella tularensis live vaccine strain (LVS) were evaluated. In the search for an optimal antigen to measure the immunogenicity of the vaccine in an enzyme-linked immunosorbent assay, we tested irradiation-killed LVS, an aqueous ether extract of the LVS (EEx), lipopolysaccharide (LPS) from LVS, and a virulent strain (SCHU4). Volunteers were immunized with LVS by scarification. Immunoglobulin G (IgG) responses to LVS and LPS gave the highest background titers when tested with sera from unimmunized volunteers, whereas IgA, IgG, and IgM background titers to EEx and SCHU4 were low. Vaccination caused a significant rise (P < 0.01) in IgA, IgG, and IgM titers to all antigens tested, except for the IgG response to LPS. Eighty percent of vaccinated volunteers developed a positive IgG response to EEx 14 days postvaccination, while 50% were positive to LVS. By day 14 after vaccination, 70% of immunized volunteers exhibited a positive response to EEx in an in vitro peripheral blood lymphocyte proliferation assay. EEx, a specific and sensitive antigen for evaluating immune responses of vaccinated volunteers, may be a superior antigen for the diagnosis of tularemia. PMID:7697521

  1. Biotransformation of ethanol to acetaldehyde by wild and mutant strains of methylotrophic yeast

    SciTech Connect

    Moroz, O.M.; Sibirnyi, A.A.; Ksheminskaya, G.P. |

    1995-05-01

    The conversion of ethanol to acetaldehyde by intact cells of wild and mutant strains of methylotrophic yeast Hansenula polymorpha was studied. It was established that mutations that lower the activity of aldehyde reductase and acetaldehyde dehydrogenase stimulate acetaldehyde accumulation. The highest accumulation of acetaldehyde was found in a mutant that possessed increased alcohol oxidase activity in growth on a medium with glucose. A decrease in formaldehyde dehydrogenase did not stimulate acetaldehyde accumulation. Bioconversion of ethanol to acetaldehyde was most effective at lowered temperatures due to marked suppression of catabolic alcohol oxidase inactivation, but not to the activity of this enzyme under indicated conditions. 27 refs., 4 figs., 3 tabs.

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

    PubMed

    Shimizu, Hiroyuki

    2016-04-01

    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. PMID:25448090

  3. 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

  4. Genotype Characterization of Commonly Used Newcastle Disease Virus Vaccine Strains of India

    PubMed Central

    Gaikwad, Satish; Kataria, Jag Mohan; Vakharia, Vikram N.

    2014-01-01

    Newcastle disease is an avian pathogen causing severe economic losses to the Indian poultry industry due to recurring outbreaks in vaccinated and unvaccinated flocks. India being an endemic country, advocates vaccination against the virus using lentogenic and mesogenic strains. Two virus strains which are commonly used for vaccination are strain F (a lentogenic virus) and strain R2B (a mesogenic virus). Strain F is given to 0–7 days old chicks and R2B is given to older birds which are around 6–8 weeks old. To understand the genetic makeup of these two strains, a complete genome study and phylogenetic analysis of the F, HN genes of these vaccine strains were carried out. Both the viral strains had a genome length of 15,186 nucleotides and consisted of six genes with conserved complimentary 3' leader and 5' trailer regions. The fusion protein cleavage site of strain F is GGRQGRL and strain R2B is RRQKRF. Although both the viral strains had different virulence attributes, the length of the HN protein was similar with 577 amino acids. Phylogenetic analysis of F, HN and complete genome sequences grouped these two strains in genotype II category which are considered as early genotypes and corroborated with their years of isolation. PMID:24897503

  5. Mutant selection and phenotypic and genetic characterization of ethanol-tolerant strains of Clostridium thermocellum.

    PubMed

    Shao, Xiongjun; Raman, Babu; Zhu, Mingjun; Mielenz, Jonathan R; Brown, Steven D; Guss, Adam M; Lynd, Lee R

    2011-11-01

    Clostridium thermocellum is a model microorganism for converting cellulosic biomass into fuels and chemicals via consolidated bioprocessing. One of the challenges for industrial application of this organism is its low ethanol tolerance, typically 1-2% (w/v) in wild-type strains. In this study, we report the development and characterization of mutant C. thermocellum strains that can grow in the presence of high ethanol concentrations. Starting from a single colony, wild-type C. thermocellum ATCC 27405 was sub-cultured and adapted for growth in up to 50 g/L ethanol using either cellobiose or crystalline cellulose as the growth substrate. Both the adapted strains retained their ability to grow on either substrate and displayed a higher growth rate and biomass yield than the wild-type strain in the absence of ethanol. With added ethanol in the media, the mutant strains displayed an inverse correlation between ethanol concentration and growth rate or biomass yield. Genome sequencing revealed six common mutations in the two ethanol-tolerant strains including an alcohol dehydrogenase gene and genes involved in arginine/pyrimidine biosynthetic pathway. The potential role of these mutations in ethanol tolerance phenotype is discussed. PMID:21874277

  6. Mutant selection and phenotypic and genetic characterization of ethanol-tolerant strains of Clostridium thermocellum

    SciTech Connect

    Shao, Xiongjun; Raman, Babu; Zhu, Mingjun; Mielenz, Jonathan R; Brown, Steven D; Guss, Adam M; Lynd, Lee R

    2011-01-01

    Clostridium thermocellum is a model microorganism for converting cellulosic biomass into fuels and chemicals via consolidated bioprocessing. One of the challenges for industrial application of this organism is its low ethanol tolerance, typically 1-2% (w/v) in wild-type strains. In this study, we report the development and characterization of mutant C. thermocellum strains that can grow in the presence of high ethanol concentrations. Starting from a single colony, wild-type C. thermocellum ATCC 27405 was sub-cultured and adapted for growth in up to 50 g/L ethanol using either cellobiose or crystalline cellulose as the growth substrate. Both the adapted strains retained their ability to grow on either substrate and displayed a higher growth rate and biomass yield than the wild-type strain in the absence of ethanol. With added ethanol in the media, the mutant strains displayed an inverse correlation between ethanol concentration and growth rate or biomass yield. Genome sequencing revealed six common mutations in the two ethanol-tolerant strains including an alcohol dehydrogenase gene and genes involved in arginine/pyrimidine biosynthetic pathway. The potential role of these mutations in ethanol tolerance phenotype is discussed.

  7. Mutant selection and phenotypic and genetic characterization of ethanol-tolerant strains of Clostridium thermocellum

    SciTech Connect

    Lynd, Lee R; Shao, Xiongjun; Raman, Babu; Mielenz, Jonathan R; Brown, Steven D; Guss, Adam M; Zhu, Mingjun

    2011-01-01

    Clostridium thermocellum is a model microorganism for converting cellulosic biomass into fuels and chemicals via consolidated bioprocessing. One of the challenges for industrial application of this organism is its low ethanol tolerance, typically 1 2% (w/v) in wild-type strains. In this study, we report the development and characterization of mutant C. thermocellum strains that can grow in the presence of high ethanol concentrations. Starting from a single colony, wild-type C. thermocellum ATCC 27405 was sub-cultured and adapted for growth in up to 50 g/L ethanol using either cellobiose or crystalline cellulose as the growth substrate. Both the adapted strains retained their ability to grow on either substrate and displayed a higher growth rate and biomass yield than the wild-type strain in the absence of ethanol. With added ethanol in the media, the mutant strains displayed an inverse correlation between ethanol concentration and growth rate or biomass yield. Genome sequencing revealed six common mutations in the two ethanol-tolerant strains including an alcohol dehydrogenase gene and genes involved in arginine/pyrimidine biosynthetic pathway. The potential role of these mutations in ethanol tolerance phenotype is discussed.

  8. TLP01, an mshA mutant of Vibrio cholerae O139 as vaccine candidate against cholera.

    PubMed

    Ledón, Talena; Ferrán, Beatriz; Pérez, Celso; Suzarte, Edith; Vichi, Joivier; Marrero, Karen; Oliva, Reinaldo; Fando, Rafael

    2012-09-01

    No commercially live vaccine against cholera caused by Vibrio cholerae O139 serogroup is available and it is currently needed. Virulent O139 strain CRC266 was genetically modified by firstly deleting multiple copies of the filamentous phage CTXφ, further tagging by insertion of the endoglucanase A coding gene from Clostridium thermocellum into the hemagglutinin/protease gene and finally deleting the mshA gene, just to improve the vaccine biosafety. One of the derived strains designated as TLP01 showed full attenuation and good colonizing capacity in the infant mouse cholera model, as well as highly immunogenic properties in the adult rabbit and rat models. Since TLP01 lacks MSHA fimbriae, it is refractory to infection with another filamentous phage VGJφ and therefore protected of acquiring CTXφ from a recombinant hybrid VGJφ/CTXφ. This strategy could reduce the possibilities of stable reversion to virulence out of the human gut. Furthermore, this vaccine strain was impaired to produce biofilms under certain culture conditions, which might have implications for the strain survival in natural settings contributing to vaccine biosafety as well. The above results has encouraged us to consider TLP01 as a live attenuated vaccine strain having an adequate performance in animal models, in terms of attenuation and immunogenicity, so that it fulfills the requirements to be evaluated in human volunteers. PMID:22546527

  9. Effects of challenge with a virulent genotype II strain of porcine reproductive and respiratory syndrome virus on piglets vaccinated with an attenuated genotype I strain vaccine.

    PubMed

    Roca, M; Gimeno, M; Bruguera, S; Segalés, J; Díaz, I; Galindo-Cardiel, I J; Martínez, E; Darwich, L; Fang, Y; Maldonado, J; March, R; Mateu, E

    2012-07-01

    Porcine reproductive and respiratory syndrome virus (PRRSV) is endemic in most parts of Asia, where genotype I and II strains of diverse virulence may coexist. This study evaluated the outcome of infection with a highly virulent Asian genotype II PRRSV isolate in piglets vaccinated with a genotype I vaccine. Twenty-one 3-week-old piglets were divided in three groups: Pigs in group V (n=8) were vaccinated with an attenuated genotype I commercial PRRSV vaccine, while pigs in group U (n=8) and a control group (group C; n=5) were unvaccinated; 6 weeks later, pigs in groups V and U were challenged intranasally with a highly virulent strain of genotype II PRRSV (1×10(5) 50% tissue culture infectious doses/mL), while pigs in group C received a placebo. Over a period of 21 days after challenge, vaccinated pigs had significantly lower mortality (0/8 versus 2/8), fewer days of fever, a lower frequency of catarrhal bronchopneumonia, higher weight gains (13.4 versus 6.6 kg) and lower levels of viraemia compared to unvaccinated challenged pigs. Immunisation with a genotype I attenuated PRRSV vaccine provided partial protection against challenge with a highly virulent genotype II strain. PMID:22264642

  10. 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

  11. Experimental studies with homologous subtype vaccines produced with multiple antigenically different seed strains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Due to the high antigenic variability of avian influenza virus, vaccines need to be continually updated to maintain adequate protection to evolving field strains. One possible approach, to mitigating the effects of antigenic change, is to use vaccines containing more than one isolate of the same su...

  12. Improved Newcastle disease vaccine approaches using virus strains selected on antigenic composition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Virulent Newcastle disease viruses (NDV) from the 1971 to 2002 U.S. outbreaks, are the same serotype but a different genotype than current vaccine strains. It is widely recognized that an efficacious Newcastle disease (ND) vaccine made with any NDV does induce protection against morbidity and morta...

  13. Genome sequence of SG33 strain and recombination between wild-type and vaccine myxoma viruses.

    PubMed

    Camus-Bouclainville, Christelle; Gretillat, Magalie; Py, Robert; Gelfi, Jacqueline; Guérin, Jean Luc; Bertagnoli, Stéphane

    2011-04-01

    Myxomatosis in Europe is the result of the release of a South America strain of myxoma virus in 1952. Several attenuated strains with origins in South America or California have since been used as vaccines in the rabbit industry. We sequenced the genome of the SG33 myxoma virus vaccine strain and compared it with those of other myxoma virus strains. We show that SG33 genome carries a large deletion in its right end. Furthermore, our data strongly suggest that the virus isolate from which SG33 is derived results from an in vivo recombination between a wild-type South America (Lausanne) strain and a California MSD-derived strain. These findings raise questions about the use of insufficiently attenuated virus in vaccination. PMID:21470452

  14. Live Attenuated Mutants of Francisella tularensis Protect Rabbits against Aerosol Challenge with a Virulent Type A Strain

    PubMed Central

    Smith, Le'Kneitah P.; Cole, Kelly Stefano; Santiago, Araceli E.; Mann, Barbara J.; Barry, Eileen M.

    2014-01-01

    Francisella tularensis, a Gram-negative bacterium, is the causative agent of tularemia. No licensed vaccine is currently available for protection against tularemia, although an attenuated strain, dubbed the live vaccine strain (LVS), is given to at-risk laboratory personnel as an investigational new drug (IND). In an effort to develop a vaccine that offers better protection, recombinant attenuated derivatives of a virulent type A strain, SCHU S4, were evaluated in New Zealand White (NZW) rabbits. Rabbits vaccinated via scarification with the three attenuated derivatives (SCHU S4 ΔguaBA, ΔaroD, and ΔfipB strains) or with LVS developed a mild fever, but no weight loss was detected. Twenty-one days after vaccination, all vaccinated rabbits were seropositive for IgG to F. tularensis lipopolysaccharide (LPS). Thirty days after vaccination, all rabbits were challenged with aerosolized SCHU S4 at doses ranging from 50 to 500 50% lethal doses (LD50). All rabbits developed fevers and weight loss after challenge, but the severity was greater for mock-vaccinated rabbits. The ΔguaBA and ΔaroD SCHU S4 derivatives provided partial protection against death (27 to 36%) and a prolonged time to death compared to results for the mock-vaccinated group. In contrast, LVS and the ΔfipB strain both prolonged the time to death, but there were no survivors from the challenge. This is the first demonstration of vaccine efficacy against aerosol challenge with virulent type A F. tularensis in a species other than a rodent since the original work with LVS in the 1960s. The ΔguaBA and ΔaroD SCHU S4 derivatives warrant further evaluation and consideration as potential vaccines for tularemia and for identification of immunological correlates of protection. PMID:24614653

  15. Vaccination with non-toxic mutant toxic shock syndrome toxin-1 induces IL-17-dependent protection against Staphylococcus aureus infection.

    PubMed

    Narita, Kouji; Hu, Dong-Liang; Asano, Krisana; Nakane, Akio

    2015-06-01

    Toxic shock syndrome toxin-1 (TSST-1) is one of superantigens produced by Staphylococcus aureus. We have previously demonstrated that vaccination with non-toxic mutant TSST-1 (mTSST-1) develops host protection to lethal S. aureus infection in mice. However, the detailed mechanism underlying this protection is necessary to elucidate because the passive transfer of antibodies against TSST-1 fails to provide complete protection against S. aureus infection. In this study, the results showed that interleukin-17A (IL-17A)-producing cells were increased in the spleen cells of mTSST-1-vaccinated mice. The main source of IL-17A in mTSST-1-vaccinated mice was T-helper 17 (Th17) cells. The protective effect of vaccination was induced when the vaccinated wild type but not IL-17A-deficient mice were challenged with S. aureus. Gene expression of chemokines, CCL2 and CXCL1, and infiltration of neutrophils and macrophages were increased in spleens and livers of vaccinated mice after infection. The IL-17A-dependent immune response was TSST-1 specific because TSST-1-deficient S. aureus failed to induce the response. The present study suggests that mTSST-1 vaccination is able to provide the IL-17A-dependent host defense against S. aureus infection which promotes chemokine-mediated infiltration of phagocytes into the infectious foci. PMID:25857736

  16. Efficacy of Brucella suis strain 2 vaccine against Brucella ovis in rams.

    PubMed

    Blasco, J M; Marín, C; Jiménez de Bagüés, M P; Barberán, M

    1993-10-01

    The protective efficacy against Brucella ovis of live vaccine Brucella suis strain 2 (S2) and Brucella melitensis strain Rev 1 has been evaluated in rams. Fourteen 4-month-old Brucella-free Aragonesa rams were vaccinated conjunctivally with 2 x 10(9) c.f.u. S2. Sixteen rams of the same breed, condition and age were conjunctivally vaccinated the same day with 1.6 x 10(9) Rev 1. Thirteen rams were unvaccinated controls. Eight months after vaccination all rams were challenged with 6 x 10(9) c.f.u. B. ovis and slaughtered 2 months thereafter for bacteriological and pathological studies. The percentage of infection in the group vaccinated with Rev 1 (43.7%) was significantly lower (p < 0.05) than that of the S2-vaccinated animals (78.6%) and unvaccinated controls (84.6%). No significant differences were found when comparing the percentages of infection corresponding to S2-vaccinated and control groups. The degree of infection (percentage of necropsy samples infected) was significantly lower in Rev 1-vaccinated (13%) than in S2-vaccinated (36.9%) or control groups (47.4%) (p < 0.001). However, no significant differences were found when comparing S2-vaccinated and control groups. PMID:8296481

  17. Genomic variations associated with attenuation in Mycobacterium avium subsp. paratuberculosis vaccine strains

    PubMed Central

    2013-01-01

    Background Mycobacterium avium subspecies paratuberculosis (MAP) whole cell vaccines have been widely used tools in the control of Johne’s disease in animals despite being unable to provide complete protection. Current vaccine strains derive from stocks created many decades ago; however their genotypes, underlying mechanisms and relative degree of their attenuation are largely unknown. Results Using mouse virulence studies we confirm that MAP vaccine strains 316 F, II and 2e have diverse but clearly attenuated survival and persistence characteristics compared with wild type strains. Using a pan genomic microarray we characterise the genomic variations in a panel of vaccine strains sourced from stocks spanning over 40 years of maintenance. We describe multiple genomic variations specific for individual vaccine stocks in both deletion (26–32 Kbp) and tandem duplicated (11–40 Kbp) large variable genomic islands and insertion sequence copy numbers. We show individual differences suitable for diagnostic differentiation between vaccine and wild type genotypes and provide evidence for functionality of some of the deleted MAP-specific genes and their possible relation to attenuation. Conclusions This study shows how culture environments have influenced MAP genome diversity resulting in large tandem genomic duplications, deletions and transposable element activity. In combination with classical selective systematic subculture this has led to fixation of specific MAP genomic alterations in some vaccine strain lineages which link the resulting attenuated phenotypes with deficiencies in high reactive oxygen species handling. PMID:23339684

  18. Impact of variation in acute virulence of BVDV1 strains on design of better vaccine efficacy challenge models

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Due to antigenic differences between BVDV1 and BVDV2 strains both pestivirus species are included in U.S. vaccines. The efficacy of these vaccines in preventing acute infections is evaluated based on reduction of clinical disease. While high virulence BVDV2 strains are used in U.S. vaccine efficac...

  19. Long-term follow-up of patients with resected pancreatic cancer following vaccination against mutant K-ras.

    PubMed

    Wedén, Synne; Klemp, Marianne; Gladhaug, Ivar P; Møller, Mona; Eriksen, Jon Amund; Gaudernack, Gustav; Buanes, Trond

    2011-03-01

    K-ras mutations are frequently found in adenocarcinomas of the pancreas and can elicit mutation-specific immune responses. Targeting the immune system against mutant Ras may thus influence the clinical course of the disease. Twenty-three patients who were vaccinated after surgical resection for pancreatic adenocarcinoma (22 pancreaticoduodenectomies, one distal resection), in two previous Phase I/II clinical trials, were followed for more than 10 years with respect to long-term immunological T-cell reactivity and survival. The vaccine was composed of long synthetic mutant ras peptides designed mainly to elicit T-helper responses. Seventeen of 20 evaluable patients (85%) responded immunologically to the vaccine. Median survival for all patients was 27.5 months and 28 months for immune responders. The 5-year survival was 22% and 29%, respectively. Strikingly, 10-year survival was 20% (four patients out of 20 evaluable) versus zero (0/87) in a cohort of nonvaccinated patient treated in the same period. Three patients mounted a memory response up to 9 years after vaccination. The present observation of long-term immune response together with 10-year survival following surgical resection indicates that K-ras vaccination may consolidate the effect of surgery and represent an adjuvant treatment option for the future. PMID:20473937

  20. Development of a mutant strain of Bacillus polymyxa showing enhanced production of 2,3-butanediol

    SciTech Connect

    Mallonee, D.H.; Speckman, R.A.

    1988-01-01

    2,3-Butanediol is a feedstock chemical of potential industrial importance. It can serve as a monomer for many polymers of consumer interest that are currently supplied by the fossil fuel industry. Bacillus polymyxa can grow on inexpensive waste products of the food-processing industry and produce this glycol. This paper describes a mutant strain of B. polymyxa which displays constitutive production of catabolic ..cap alpha..-acetolactate synthase, an enzyme in the 2,3-butanediol pathway which is normally produced only in the late log or stationary phase of growth. The mutant was obtained by treating the wild type with nitrosoguanidine and subjecting it to a penicillin counterselection procedure. One of the selected mutant strains produced four times as much of the glycol as the wild type and utilized approximately 25% of the energy source, compared with essentially complete utilization of the energy source by the wild type. Studies are under way to optimize the production of the glycol by the mutant.

  1. Identification of in vitro upregulated genes in a modified live vaccine strain of Edwardsiella ictaluri compared to a virulent parent strain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Using PCR-select subtractive cDNA hybridization technique, 41 expressed sequence tags (ESTs) were isolated from a modified live vaccine strain (AQUAVAC-ESC©, formerly RE-33) vs a virulent parent strain (EILO) of Edwardsiella ictaluri. Transcriptional levels of the 41 ESTs in the vaccine strain and t...

  2. Molecular characterization of the Israeli B. bigemina vaccine strain and field isolates.

    PubMed

    Molad, T; Erster, O; Fleiderovitz, L; Roth, A; Leibovitz, B; Wolkomirsky, R; Mazuz, M L; Behar, A; Markovics, A

    2015-09-15

    The present study demonstrated the genetic character of the Israeli Babesia bigemina vaccine strain and field isolates, based on rap-1a and rap-1c gene sequences. The RAP-1a of blood-derived Israeli B. bigemina field isolates shared 100% amino acid sequence identity. However, comparison of RAP-1c from various Israeli B. bigemina field isolates revealed that the total sequence identity among the field isolates ranged from 98.2 to 100%. High identity was observed when RAP-1a sequences from the Israeli vaccine strain and field isolates were compared with RAP-1a from Egypt, Syria, Mexico and South Africa, while, the Israeli RAP-1c sequences showed the highest identity to the Mexican isolate JG-29 and to the PR isolate from Puerto-Rico. Based on sequence variations between the rap-1a of the vaccine strain and that of the field isolate, and between the rap-1c of the vaccine strain and that of the field isolates, nPCR-RFLP procedures were developed that enable, for the first time differentiation between the Israeli B. bigemina vaccine strain and field-infection isolates. These assays could serve as fast and sensitive methods for detection and differentiation between Israeli B. bigemina vaccine strains and field isolates, as well as for epidemiological investigations. PMID:26154404

  3. Draft Genome Sequences for Clostridium thermocellum Wild-Type Strain YS and Derived Cellulose Adhesion-Defective Mutant Strain AD2

    SciTech Connect

    Brown, Steven D; Lamed, Raphael; Morag, Ely; Borovok, Ilya; Shoham, Yuval; Klingeman, Dawn Marie; Johnson, Courtney M; Yang, Zamin; Land, Miriam L; Utturkar, Sagar M; Keller, Martin; Bayer, Edward A

    2012-01-01

    Clostridium thermocellum wild-type strain YS is an anaerobic, thermophilic, cellulolytic bacterium capable of directly converting cellulosic substrates into ethanol. Strain YS and a derived cellulose adhesion-defective mutant strain AD2 played pivotal roles in describing the original cellulosome concept. We present their draft genome sequences.

  4. 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. PMID:26292544

  5. Mathematical model of tuberculosis transmission in a two-strain with vaccination

    NASA Astrophysics Data System (ADS)

    Nainggolan, J.; Supian, S.; Supriatna, A. K.; Anggriani, N.

    2014-02-01

    This paper deals with the mathematical analysis of the spread of tuberculosis with vaccination in a two-strain model. The vaccination reproduction ratio (Rrs) and equilibria quantities for the models are determined and stability of the solution is analyzed. We prove that if the vaccination reproduction ratio Rrs < 1 the disease free equilibrium is locally and asymptotically stable on the nonnegative orthant and if Rrs > 1 of the other equilibria is locally and asymptotically stable. At the end of this study, the numerical computation presented and it shows that vaccination and treatment capable to reduce the number of exposed and infected compartments.

  6. Isolation and characterization of symbiotic mutants of bradyrhizobium sp. (Arachis) strain NC92: mutants with host-specific defects in nodulation and nitrogen fixation.

    PubMed Central

    Wilson, K J; Anjaiah, V; Nambiar, P T; Ausubel, F M

    1987-01-01

    Random transposon Tn5 mutagenesis of Bradyrhizobium sp. (Arachis) strain NC92, a member of the cowpea cross-inoculation group, was carried out, and kanamycin-resistant transconjugants were tested for their symbiotic phenotype on three host plants: groundnut, siratro, and pigeonpea. Two nodulation (Nod- phenotype) mutants were isolated. One is unable to nodulate all three hosts and appears to contain an insertion in one of the common nodulation genes (nodABCD); the other is a host-specific nodulation mutant that fails to nodulate pigeonpea, elicits uninvaded nodules on siratro, and elicits normal, nitrogen-fixing nodules on groundnut. In addition, nine mutants defective in nitrogen fixation (Fix- phenotype) were isolated. Three fail to supply symbiotically fixed nitrogen to all three host plants. Surprisingly, nodules elicited by one of these mutants exhibit high levels of acetylene reduction activity, demonstrating the presence of the enzyme nitrogenase. Three more mutants have partially effective phenotypes (Fix +/-) in symbiosis with all three host plants. The remaining three mutants fail to supply fixed nitrogen to one of the host plants tested while remaining partially or fully effective on the other two hosts; two of these mutants are Fix- in pigeonpea and Fix +/- on groundnut and on siratro, whereas the other one is Fix- on groundnut but Fix+ on siratro and on pigeonpea. These latter mutants also retain significant nodule acetylene reduction activity, even in the ineffective symbioses. Such bacterial host-specific fixation (Hsf) mutants have not previously been reported. Images PMID:3032910

  7. Vaccination against Anthrax with Attenuated Recombinant Strains of Bacillus anthracis That Produce Protective Antigen

    PubMed Central

    Barnard, John P.; Friedlander, Arthur M.

    1999-01-01

    The protective efficacy of several live, recombinant anthrax vaccines given in a single-dose regimen was assessed with Hartley guinea pigs. These live vaccines were created by transforming ΔANR and ΔSterne, two nonencapsulated, nontoxinogenic strains of Bacillus anthracis, with four different recombinant plasmids that express the anthrax protective antigen (PA) protein to various degrees. This enabled us to assess the effect of the chromosomal background of the strain, as well as the amount of PA produced, on protective efficacy. There were no significant strain-related effects on PA production in vitro, plasmid stability in vivo, survival of the immunizing strain in the host, or protective efficacy of the immunizing infection. The protective efficacy of the live, recombinant anthrax vaccine strains correlated with the anti-PA antibody titers they elicited in vivo and the level of PA they produced in vitro. PMID:9916059

  8. An outbreak of mumps in a population partially vaccinated with the Rubini strain.

    PubMed

    Germann, D; Ströhle, A; Eggenberger, K; Steiner, C A; Matter, L

    1996-01-01

    Since 1991, 6 years after the recommendation of universal childhood triple vaccination against measles, mumps and rubella (M + M + R), Switzerland has been confronted with an increasing number of mumps cases affecting both vaccinated and unvaccinated children. The M + M + R vaccine mainly used in the Swiss population after 1986 contains the highly attenuated Rubini strain of mumps virus. We analysed an outbreak of 102 suspected mumps cases by virus isolation, determination of IgM antibodies to mumps virus in 27 acute phase sera, and verification of vaccination histories. Mumps was confirmed by virus isolation in 88 patients, of whom 72 had previously received the Rubini vaccine strain. IgM antibodies to mumps virus were detected in 24/27 acute phase serum samples. A group of 92 subjects from the same geographic area without signs of mumps virus infection served as controls. IgG antibodies to mumps virus and vaccination status were assessed in these children. The vaccination rate in these controls was 61%, with equal seropositivity for unvaccinated and Rubini-vaccinated subjects. These data support other recent reports which indicate an insufficient protective efficacy of current mumps vaccines. PMID:8863352

  9. Sequencing analysis of Mycoplasma gallisepticum wild strains in vaccinated chicken breeder flocks.

    PubMed

    Khalifa, Rabab; Eissa, Sabry; El-Hariri, Mahmoud; Refai, Mohamed

    2014-01-01

    Mycoplasma gallisepticum (MG) infection is still of continuing economic concern in commercial broiler breeder chicken flocks in Egypt. MG infection continues to emerge despite the application of vaccination programs in breeder flocks. This prompted flock surveillance including MG isolation and molecular characterization of the circulating MG strains. The present study was concerned with 15 broiler breeder flocks of different ages (5-51 weeks). Three flocks were apparently healthy and 12 flocks were diseased. The aim of the study was to characterize the MG strains recovered from tracheal swabs. Four positive MG DNA extracts identified by rt-PCR and confirmed by isolation were subjected to sequencing of the mgc2 gene and intergenic spacer region (IGSR). The current molecular study demonstrated the presence of 3 different wild-type MG strains (RabE1-08, RabE2-09 and RabE3-09) in vaccinated diseased flocks, while the fourth strain (RabE4-08), which was isolated from a nonvaccinated apparently healthy breeder flock, scored 100% of homology and similarity to the F-strain vaccine by the sequence analysis of mgc2 and IGSR. It can be assumed that the vaccine F strain, which is supposed to replace field strains not only failed to do that, but also infected nonvaccinated flocks. Accordingly, there is a need to revise the control program including vaccine strategy in parallel with biosecurity measures. PMID:24525899

  10. Mutants of Rhizobium tropici strain CIAT899 that do not induce chlorosis in plants.

    PubMed

    O'Connell, K P; Raffel, S J; Saville, B J; Handelsman, J

    1998-09-01

    Type B strains of Rhizobium tropici induce severe foliar chlorosis when applied at planting to seeds of symbiotic host and non-host dicotyledonous plants. A Tn5-induced mutant, designated CT4812, or R. tropici strain CIAT899 that was unable to induce chlorosis was isolated. Cloning and sequencing of the DNA flanking the transposon in CT4812 revealed that the Tn5 insertion is located in a gene similar to glnD, which encodes uridylyltransferase/uridylyl-removing enzyme in enteric bacteria. Two marker-exchange mutants with insertions in glnD also failed to induce chlorosis in bean (Phaseolus vulgaris) plants. The 5'-most insertion in glnD (in mutant strain ME330) abolished the ability of R. tropici to utilize nitrate as a sole carbon source, whereas a mutation in glnD further downstream (in mutant strain ME245) did not have an obvious effect on nitrate utilization. A gene similar to the Salmonella typhimurium virulence gene mviN overlaps the 3' end of the R. tropici glnD homologue. A mutation in mviN had no effect on the ability of CIAT899 to induce chlorosis in bean plants. Therefore the glnD homologue, but not mviN, appears to be required for induction of chlorosis in plants by R. tropici strain CIAT899. A high nitrogen: carbon ratio in the rhizosphere of bean plants also prevented R. tropici from inducing chlorosis in bean plants. Mutations in either the glnD homologue or mviN had no significant effect on root nodule formation or acetylene reduction activity. A mutation in mviN eliminated motility in R. tropici. The sequence data, the inability of the glnD mutant to utilize nitrate, and the role of the R. tropici glnD gene in chlorosis induction in plants, a process that is nitrogen regulated, suggest that glnD plays a role in nitrogen sensing in R. tropici as its homologues do in other organisms. PMID:9782510

  11. 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

  12. Association between Interferon Response and Protective Efficacy of NS1-Truncated Mutants as Influenza Vaccine Candidates in Chickens.

    PubMed

    Jang, Hyesun; Ngunjiri, John M; Lee, Chang-Won

    2016-01-01

    Influenza virus mutants that encode C-terminally truncated NS1 proteins (NS1-truncated mutants) are attractive candidates for avian live attenuated influenza vaccine (LAIV) development because they are both attenuated and immunogenic in chickens. We previously showed that a high protective efficacy of NS1-truncated LAIV in chickens corresponds with induction of high levels of type I interferon (IFN) responses in chicken embryonic fibroblast cells. In this study, we investigated the relationship between induction of IFN and IFN-stimulated gene responses in vivo and the immunogenicity and protective efficacy of NS1-truncated LAIV. Our data demonstrates that accelerated antibody induction and protective efficacy of NS1-truncated LAIV correlates well with upregulation of IFN-stimulated genes. Further, through oral administration of recombinant chicken IFN alpha in drinking water, we provide direct evidence that type I IFN can promote rapid induction of adaptive immune responses and protective efficacy of influenza vaccine in chickens. PMID:27257989

  13. Association between Interferon Response and Protective Efficacy of NS1-Truncated Mutants as Influenza Vaccine Candidates in Chickens

    PubMed Central

    Jang, Hyesun; Ngunjiri, John M.; Lee, Chang-Won

    2016-01-01

    Influenza virus mutants that encode C-terminally truncated NS1 proteins (NS1-truncated mutants) are attractive candidates for avian live attenuated influenza vaccine (LAIV) development because they are both attenuated and immunogenic in chickens. We previously showed that a high protective efficacy of NS1-truncated LAIV in chickens corresponds with induction of high levels of type I interferon (IFN) responses in chicken embryonic fibroblast cells. In this study, we investigated the relationship between induction of IFN and IFN-stimulated gene responses in vivo and the immunogenicity and protective efficacy of NS1-truncated LAIV. Our data demonstrates that accelerated antibody induction and protective efficacy of NS1-truncated LAIV correlates well with upregulation of IFN-stimulated genes. Further, through oral administration of recombinant chicken IFN alpha in drinking water, we provide direct evidence that type I IFN can promote rapid induction of adaptive immune responses and protective efficacy of influenza vaccine in chickens. PMID:27257989

  14. Evaluation of an attenuated strain of Ehrlichia canis as a vaccine for canine monocytic ehrlichiosis.

    PubMed

    Rudoler, Nir; Baneth, Gad; Eyal, Osnat; van Straten, Michael; Harrus, Shimon

    2012-12-17

    Canine monocytic ehrlichiosis is an important tick-borne disease worldwide. No commercial vaccine for the disease is currently available and tick control is the main preventive measure against the disease. The aim of this study was to evaluate the potential of a multi-passaged attenuated strain of Ehrlichia canis to serve as a vaccine for canine monocytic ehrlichiosis, and to assess the use of azithromycin in the treatment of acute ehrlichiosis. Twelve beagle dogs were divided into 3 groups of 4 dogs. Groups 1 and 2 were inoculated (vaccinated) with an attenuated strain of E. canis (#611A) twice or once, respectively. The third group consisted of naïve dogs which served as controls. All 3 groups were challenged with a wild virulent strain of E. canis by administering infected dog-blood intravenously. Transient thrombocytopenia was the only hematological abnormality observed following inoculation of dogs with the attenuated strain. Challenge with the virulent strain resulted in severe disease in all 4 control dogs while only 3 of 8 vaccinated dogs presented mild transient fever. Furthermore, the mean blood rickettsial load was significantly higher in the control group (27-92-folds higher during days 14-19 post challenge with the wild the strain) as compared to the vaccinated dogs. The use of azithromycin was assessed as a therapeutic agent for the acute disease. Four days treatment resulted in further deterioration of the clinical condition of the dogs. Molecular comparison of 4 genes known to express immunoreactive proteins and virulence factors (p30, gp19, VirB4 and VirB9) between the attenuated strain and the challenge wild strain revealed no genetic differences between the strains. The results of this study indicate that the attenuated E. canis strain may serve as an effective and secure future vaccine for canine ehrlichiosis. PMID:23072894

  15. Safety and immunogenicity of a vaccine bait containing ERA strain of attenuated rabies virus.

    PubMed

    Lawson, K F; Black, J G; Charlton, K M; Johnston, D H; Rhodes, A J

    1987-10-01

    Ninety percent of foxes fed commercial ERA vaccine in a specially designed bait developed rabies serum neutralizing antibodies. The vaccine bait did not cause clinical signs of rabies when consumed by foxes, raccoons, skunks, dogs, cats, cattle and monkeys. When presented, in the laboratory, to wild rodents of the species Microtus, Mus musculus and Peromyscus, the vaccine baits caused vaccine-induced rabies only in Mus musculus. Laboratory mice of the CD-1 and CLL strain were susceptible to vaccine-induced rabies; however, studies showed that transmission of virus to other animals did not occur. These studies suggest that the vaccine bait described could be useful in a rabies control program in areas where foxes and wild dogs are the principal vectors. PMID:3330965

  16. Genome Sequence of Brucella abortus Vaccine Strain S19 Compared to Virulent Strains Yields Candidate Virulence Genes

    PubMed Central

    Crasta, Oswald R.; Folkerts, Otto; Fei, Zhangjun; Mane, Shrinivasrao P.; Evans, Clive; Martino-Catt, Susan; Bricker, Betsy; Yu, GongXin; Du, Lei; Sobral, Bruno W.

    2008-01-01

    The Brucella abortus strain S19, a spontaneously attenuated strain, has been used as a vaccine strain in vaccination of cattle against brucellosis for six decades. Despite many studies, the physiological and molecular mechanisms causing the attenuation are not known. We have applied pyrosequencing technology together with conventional sequencing to rapidly and comprehensively determine the complete genome sequence of the attenuated Brucella abortus vaccine strain S19. The main goal of this study is to identify candidate virulence genes by systematic comparative analysis of the attenuated strain with the published genome sequences of two virulent and closely related strains of B. abortus, 9–941 and 2308. The two S19 chromosomes are 2,122,487 and 1,161,449 bp in length. A total of 3062 genes were identified and annotated. Pairwise and reciprocal genome comparisons resulted in a total of 263 genes that were non-identical between the S19 genome and any of the two virulent strains. Amongst these, 45 genes were consistently different between the attenuated strain and the two virulent strains but were identical amongst the virulent strains, which included only two of the 236 genes that have been implicated as virulence factors in literature. The functional analyses of the differences have revealed a total of 24 genes that may be associated with the loss of virulence in S19. Of particular relevance are four genes with more than 60bp consistent difference in S19 compared to both the virulent strains, which, in the virulent strains, encode an outer membrane protein and three proteins involved in erythritol uptake or metabolism. PMID:18478107

  17. Genome sequence of Brucella abortus vaccine strain S19 compared to virulent strains yields candidate virulence genes.

    PubMed

    Crasta, Oswald R; Folkerts, Otto; Fei, Zhangjun; Mane, Shrinivasrao P; Evans, Clive; Martino-Catt, Susan; Bricker, Betsy; Yu, GongXin; Du, Lei; Sobral, Bruno W

    2008-01-01

    The Brucella abortus strain S19, a spontaneously attenuated strain, has been used as a vaccine strain in vaccination of cattle against brucellosis for six decades. Despite many studies, the physiological and molecular mechanisms causing the attenuation are not known. We have applied pyrosequencing technology together with conventional sequencing to rapidly and comprehensively determine the complete genome sequence of the attenuated Brucella abortus vaccine strain S19. The main goal of this study is to identify candidate virulence genes by systematic comparative analysis of the attenuated strain with the published genome sequences of two virulent and closely related strains of B. abortus, 9-941 and 2308. The two S19 chromosomes are 2,122,487 and 1,161,449 bp in length. A total of 3062 genes were identified and annotated. Pairwise and reciprocal genome comparisons resulted in a total of 263 genes that were non-identical between the S19 genome and any of the two virulent strains. Amongst these, 45 genes were consistently different between the attenuated strain and the two virulent strains but were identical amongst the virulent strains, which included only two of the 236 genes that have been implicated as virulence factors in literature. The functional analyses of the differences have revealed a total of 24 genes that may be associated with the loss of virulence in S19. Of particular relevance are four genes with more than 60 bp consistent difference in S19 compared to both the virulent strains, which, in the virulent strains, encode an outer membrane protein and three proteins involved in erythritol uptake or metabolism. PMID:18478107

  18. 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.

  19. 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. PMID:24798148

  20. Sequence Variation and Immunologic Cross-Reactivity among Babesia bovis Merozoite Surface Antigen 1 Proteins from Vaccine Strains and Vaccine Breakthrough Isolates

    PubMed Central

    LeRoith, Tanya; Brayton, Kelly A.; Molloy, John B.; Bock, Russell E.; Hines, Stephen A.; Lew, Ala E.; McElwain, Terry F.

    2005-01-01

    The Babesia bovis merozoite surface antigen 1 (MSA-1) is an immunodominant membrane glycoprotein that is the target of invasion-blocking antibodies. While antigenic variation has been demonstrated in MSA-1 among strains from distinct geographical areas, the extent of sequence variation within a region where it is endemic and the effect of variation on immunologic cross-reactivity have not been assessed. In this study, sequencing of MSA-1 from two Australian B. bovis vaccine strains and 14 breakthrough isolates from vaccinated animals demonstrated low sequence identity in the extracellular region of the molecule, ranging from 19.8 to 46.7% between the T vaccine strain and eight T vaccine breakthrough isolates, and from 18.7 to 99% between the K vaccine strain and six K vaccine breakthrough isolates. Although MSA-1 amino acid sequence varied substantially among strains, overall predicted regions of hydrophilicity and hydrophobicity in the extracellular domain were conserved in all strains examined, suggesting a conserved functional role for MSA-1 despite sequence polymorphism. Importantly, the antigenic variation created by sequence differences resulted in a lack of immunologic cross-reactivity among outbreak strains using sera from animals infected with the B. bovis vaccine strains. Additionally, sera from cattle hyperinfected with the Mexico strain of B. bovis and shown to be clinically immune did not cross-react with MSA-1 from any other isolate tested. The results indicate that isolates of B. bovis capable of evading vaccine-induced immunity contain an msa-1 gene that is significantly different from the msa-1 of the vaccine strain, and that the difference can result in a complete lack of cross-reactivity between MSA-1 from vaccine and breakthrough strains in immunized animals. PMID:16113254

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  2. Genome Sequence of Salmonella enterica Serovar Typhi Oral Vaccine Strain Ty21a.

    PubMed

    Xu, Deqi; Cisar, John O; Poly, Frédéric; Yang, Jinghua; Albanese, Jason; Dharmasena, Madushini; Wai, Tint; Guerry, Patricia; Kopecko, Dennis J

    2013-01-01

    Attenuated Salmonella enterica serovar Typhi strain Ty21a is an important vaccine for controlling typhoid fever and serves as an oral vector for delivering heterologous antigens. The key attenuating features of this randomly mutated strain remain in question. Genome sequencing has revealed 679 single nucleotide polymorphisms (SNPs), and will help define alterations contributing to Ty21a safety and immunogenicity. PMID:23969054

  3. Comparative metabolic profiling of mce1 operon mutant vs wild-type Mycobacterium tuberculosis strains.

    PubMed

    Queiroz, Adriano; Medina-Cleghorn, Daniel; Marjanovic, Olivera; Nomura, Daniel K; Riley, Lee W

    2015-11-01

    Mycobacterium tuberculosis disrupted in a 13-gene operon (mce1) accumulates free mycolic acids (FM) in its cell wall and causes accelerated death in mice. Here, to more comprehensively analyze differences in their cell wall lipid composition, we used an untargeted metabolomics approach to compare the lipid profiles of wild-type and mce1 operon mutant strains. By liquid chromatography-mass spectrometry, we identified >400 distinct lipids significantly altered in the mce1 mutant compared to wild type. These lipids included decreased levels of saccharolipids and glycerophospholipids, and increased levels of alpha-, methoxy- and keto mycolic acids (MA), and hydroxyphthioceranic acid. The mutant showed reduced expression of mmpL8, mmpL10, stf0, pks2 and papA2 genes involved in transport and metabolism of lipids recognized to induce proinflammatory response; these lipids were found to be decreased in the mutant. In contrast, the transcripts of mmpL3, fasI, kasA, kasB, acpM and RV3451 involved in MA transport and metabolism increased; MA inhibits inflammatory response in macrophages. Since the mce1 operon is known to be regulated in intracellular M. tuberculosis, we speculate that the differences we observed in cell wall lipid metabolism and composition may affect host response to M. tuberculosis infection and determine the clinical outcome of such an infection. PMID:26319139

  4. Response of layer and broiler strain chickens to parenteral administration of a live Salmonella Typhimurium vaccine.

    PubMed

    Groves, Peter J; Sharpe, Sue M; Cox, Julian M

    2015-07-01

    Responses to the parenteral administration of a live aroA deletion Salmonella serovar Typhimurium vaccine given to three brown egg layer strains and two broiler strains were studied. Twenty-five birds of each strain were reared together in floor pens to 6 weeks of age and then moved as individual strains to new floor pens and injected with 10(8) colony forming units (CFU) per bird of the vaccine bacteria intramuscularly or subcutaneously, 10(6) CFU per bird subcutaneously, or phosphate buffered saline (PBS) subcutaneously as a vaccination control. Three birds of one layer strain were injected intramuscularly with 0.5mg/ bird S. Typhimurium lipopolysaccharide (LPS) to evaluate whether response was similar for vaccine and endotoxin. Birds were weighed, and rectal temperatures recorded at the time of injection, then observed over 24 hours. Rectal temperatures were measured and blood samples collected for serum IL-6 assay at 3 hours post injection (PI). At 12 hours PI blood samples were drawn for analyses for plasma phosphorus (P), glucose (Glu), cholesterol (Cho), aspartate transaminase (AST), total protein (Ptn) and creatinine kinase (CK). Blood was sampled 14 days PI and tested for serum antibody to S. Typhimurium. Vaccination resulted in significant seroconversion by 14 days PI in all strains compared to the controls. The three layer strains exhibited a clinical malaise, evident within 90 minutes of injection, lasting for 12 hours, with complete recovery by 24 hours PI. Only the 10(8) CFU dose given subcutaneously produced an increase in rectal temperature 3 hours PI. Vaccination had no effect on IL-6 or Ptn. All vaccine doses increased P and the higher dose by either route decreased Cho in all bird strains. The 10(8) vaccine dose increased Glu and intramuscular injection markedly elevated CK only in the layer strains. The response was not completely congruous with that to LPS alone. The results highlight the need for consideration of differences in response of

  5. 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.

  6. Production and downstream processing of (1→3)-β-D-glucan from mutant strain of Agrobacterium sp. ATCC 31750

    PubMed Central

    2012-01-01

    We isolated a mutant that produced higher levels of curdlan than the wild strain Agrobacterium sp. ATCC 31750 by chemical mutagenesis using N-methyl-N-nitro-nitrosoguanidine. The mutant strain produced 66 g/L of curdlan in 120 h with a yield of (0.88) while, the wild strain produced 41 g/L in 120 h with a yield of (0.62) in a stirred bioreactor. The mutant could not produce curdlan when the pH was shifted from 7.0 to 5.5 after nitrogen depletion as followed for wild strain. In contrast, pH optimum for cell growth and curdlan production for mutant was found to be 7.0. We optimized the downstream processing of curdlan by varying different volumes of NaOH and HCl for extraction and precipitation of curdlan. The molecular weight of the purified curdlan from the wild and mutant strain was 6.6 × 105 Da and 5.8 × 105 Da respectively. The monosaccharide analyses confirm that curdlan from both wild and mutant strain contains only glucose units. From the NMR and FTIR data, it has been confirmed that curdlan was exclusively composed of β (1 → 3)-D-glucan residues. PMID:22681895

  7. 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.

  8. 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. PMID:26947495

  9. 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. PMID:25011712

  10. Vaccination With a UV-Irradiated Genetically Attenuated Mutant of Staphylococcus aureus Provides Protection Against Subsequent Systemic Infection

    PubMed Central

    Burnside, Kellie; Lembo, Annalisa; Harrell, Maria Isabel; Klein, Jessica Abbey; Lopez-Guisa, Jesus; Siegesmund, Amy M.; Torgerson, Troy R.; Oukka, Mohamed; Molina, Douglas M.; Rajagopal, Lakshmi

    2012-01-01

    Staphylococcus aureus are gram-positive bacteria that cause clinically significant infections in humans. Severe S. aureus infections are particularly problematic in hospitalized patients and reoccur despite therapeutic measures. The absence of natural protective immune responses and the lack of high-throughput approaches to identify S. aureus antigens have imposed constraints in the development of effective vaccines. Here, we showed that vaccination with the genetically attenuated S. aureus mutant, inactivated using UV irradiation rather than heat, significantly increased survival and diminished bacterial burden and kidney abscesses when mice were challenged with virulent methicillin-sensitive or methicillin-resistant S. aureus. Protection conferred by immunization could be transferred to the naive host and was not observed in B-cell–deficient mice. Using a novel S. aureus whole-proteome microarray, we show that immunoglobulin G antibody responses to 83 proteins were observed in the immunized mice. These results suggest that protection against S. aureus infections requires antibody responses to the wide repertoire of antigens/virulence factors. Vaccination using UV-irradiated genetically attenuated S. aureus induces humoral immunity and provides a vaccine strategy for pathogens that fail to induce protective immunity. We also describe a novel, high-throughput technology to easily identify S. aureus antigens for vaccine development. PMID:22966130

  11. Development of a highly immunogenic Newcastle disease virus chicken vaccine strain of duck origin.

    PubMed

    Kim, J Y; Kye, S J; Lee, H J; Gaikwad, S; Lee, H S; Jung, S C; Choi, K S

    2016-04-01

    Newcastle disease virus (NDV) strain NDRL0901 was developed as a live vaccine candidate for control of Newcastle disease. NDV isolate KR/duck/13/07 (DK1307) of duck origin was used as the selected vaccine strain. DK1307 was passaged 6 times in chickens. Then a single clone from the chicken-adapted virus (DK1307C) was finally selected, and the vaccine strain was named NDRL0901. DK1307C and the clone NDRL0901 viruses showed enhanced immunogenicity compared to the DK1307 virus. Principal component analysis based on fusion and hemagglutinin-neuraminidase genes revealed the codon usage pattern in the dataset is distinct separating duck viral sequences and avian sequences, and passage of the duck origin virus into the chicken host causes deviation in the codon usage pattern. The NDRL0901 virus was avirulent and did not acquire viral virulence even after 7 back passages in chickens. When day-old chicks were vaccinated with the NDRL0901 virus via spray, eye drops, and drinking water, the vaccinated birds showed no clinical signs and had significant protection efficacy (>80%) against very virulent NDV (Kr005 strain) infection regardless of the administration route employed. The results indicate that the NDRL0901 strain is safe in chickens and can offer protective immunity. PMID:26769266

  12. 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. PMID:19635607

  13. A diagnostic protocol to identify water buffaloes (Bubalus bubalis) vaccinated with Brucella abortus strain RB51 vaccine.

    PubMed

    Tittarelli, Manuela; Atzeni, Marcello; Calistri, Paolo; Di Giannatale, Elisabetta; Ferri, Nicola; Marchi, Enrico; Martucciello, Alessandra; De Massis, Fabrizio

    2015-01-01

    The use of live vaccine strain RB51 for vaccination of domestic water buffaloes (Bubalus bubalis) at risk of infection with Brucella abortus is permitted notwithstanding the plans for the eradication and only under strict veterinary control. The antibodies induced by RB51 vaccination are not detectable using conventional diagnostic techniques; therefore, it is necessary to have a specific diagnostic tool able to discriminate vaccinated from unvaccinated animals. The combination of a complement fixation test (CFT) with specific RB51 antigen (RB51-CFT) and a brucellin skin test has been demonstrated to be a reliable diagnostic system to identify single cattle (Bos taurus) vaccinated with RB51. So far, no data are available in the international scientific literature regarding the use of this test association in water buffalo. For this reason the suitability of this test combination has been evaluated in a water buffalo herd. One hundred twenty-seven animals farmed in a herd of Salerno province (Campania, Southern Italy), in the context of a presumptive unauthorized use of RB51 vaccine were chosen for this study. All tested animals resulted negative to Rose Bengal test (RBT) and complement fixation test (CFT) used for the detection of specific antibodies against Brucella field strains. Seventy-one animals (56%) developed RB51 antigen-specific CFT (RB51-CFT) antibodies against RB51 vaccine in a first sampling, while 104 animals (82%) gave positive result to a second serum sampling conducted 11 days after the intradermal inoculation of the RB51 brucellin. One hundred and seven animals (84%) showed a positive reaction to the RB51-CFT in at least 1 sampling, while 111 animals (87%) resulted positive to the RB51 brucellin skin test. Thus, analysing the results of the 3 testing in parallel, 119 animals (94%) were positive to at least 1 of the performed tests. The results suggest that the use in parallel of the RB51 brucellin skin test with RB51-CFT may represent a reliable

  14. The ultrastructure of a Chlamydomonas reinhardtii mutant strain lacking phytoene synthase resembles that of a colorless alga.

    PubMed

    Inwood, William; Yoshihara, Corinne; Zalpuri, Reena; Kim, Kwang-Seo; Kustu, Sydney

    2008-11-01

    Chlamydomonas reinhardtii strains lacking phytoene synthase, the first enzyme of carotenoid biosynthesis, are white. They lack carotenoid pigments, have very low levels of chlorophyll, and can grow only heterotrophically in the dark. Our electron and fluorescence microscopic studies showed that such a mutant strain (lts1-204) had a proliferated plastid envelope membrane but no stacks of thylakoid membranes within the plastid. It accumulated cytoplasmic compartments that appeared to be autophagous vacuoles filled with membranous material. The lts1 mutants apparently lacked pyrenoid bodies, which normally house ribulose bisphosphate carboxylase-oxygenase (Rubisco), and accumulated many starch granules. Although these mutant strains cannot synthesize the carotenoid and carotenoid-derived pigments present in the phototactic organelle (eyespot), the mutant we examined made a vestigial eyespot that was disorganized and often mislocalized to the posterior end of the cell. The absence of a pyrenoid body, the accumulation of starch, and the disorganization of the eyespot may all result from the absence of thylakoids. The ultrastructure of lts1 mutant strains is similar to but distinct from that of previously described white and yellow mutant strains of C. reinhardtii and is similar to that of naturally colorless algae of the Polytoma group. PMID:19825593

  15. Symbiotic effectiveness of antibiotic-resistant mutants of fast- and slow-growing strains of Rhizobium nodulating Lotus species.

    PubMed

    Pankhurst, C E

    1977-08-01

    Mutants resistant ot 16 individual antibiotics were isolated from two fast-growing and two slow-growing strains of Lotus rhizobia and their symbiotic effectiveness on Lotus pedunculatus evaluated. Resistance to streptomycin, spectinomycin, chloramphenicol, and tetracycline (inhibitors of protein synthesis) was associated with little or no loss of effectiveness with all four strains but resistance to nalidixic acid and rifampicin (inhibitors of nucleic acid synthesis), and to D-cycloserine, novobiocin, and penicillin (inhibitors of cell wall-cell membrane synthesis) was associated with significant loss of effectiveness in 20-100% of the mutants. Resistance to viomycin, neomycin, kanamycin, and vibramycin was associated with loss of effectiveness with mutants of the two fast-growing strains but not with mutants of the two slow-growing strains. When tested on four alternate host legumes individual mutants of a slow-growing strain showed significantly different levels of effectiveness. The results suggest that both the inherent characteristics of the bacterium and of the host plant will influence the symbiotic effectiveness of antibiotic-resistant mutants of Rhizobium. PMID:890601

  16. Determination of H5N1 vaccine potency using reference antisera from heterologous strains of influenza

    PubMed Central

    Vodeiko, Galina M.; Weir, Jerry P.

    2011-01-01

    Please cite this paper as: Vodeiko and Weir (2011). Determination of H5N1 vaccine potency using reference antisera from heterologous strains of influenza. Influenza and Other Respiratory Viruses 6(3), 176–187. Background  Standardization of inactivated influenza vaccines by hemagglutinin (HA) content is performed by the single radial immunodiffusion (SRID) method. Regulatory agencies prepare, calibrate, and distribute SRID reagent standards necessary for testing of seasonal influenza vaccines, and a similar process is used to produce potency reagents for candidate pandemic influenza vaccines that are manufactured for emergency stockpiles. Objectives  Because of the concerns in generating a timely strain‐specific potency antiserum for an emerging pandemic virus, we evaluated the feasibility of using heterologous potency reference antiserum as a replacement for a strain‐specific (homologous) antiserum in the SRID potency assay for stockpiled H5N1 vaccines. Results  The results indicate that a heterologous H5N1 antiserum can be used to determine the accurate potency of inactivated H5N1 influenza vaccines. Additionally, when H5N1 vaccine was subjected to an accelerated stability protocol, both homologous and heterologous antisera provided similar measurements of vaccine potency decline. Limitations to the heterologous antiserum approach to potency determination were shown by the inability of antiserum to recent seasonal H1N1 viruses to work in an SRID assay with the 2009 pandemic H1N1 A/California/07/2009 antigen. Conclusions  The data demonstrate the feasibility of using heterologous antiserum for potency determination of at least some candidate vaccines in case of a shortage or delay of homologous antiserum. Further, the results suggest the prudence of stockpiling a broad library of potency reagents including many strains of influenza viruses with pandemic potential to provide an added measure of assurance that reagent production would not be a

  17. 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

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

    PubMed

    Lanzilao, Luisa; Stefanetti, Giuseppe; 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

  19. Exploitation of Mycobacterium tuberculosis Reporter Strains to Probe the Impact of Vaccination at Sites of Infection

    PubMed Central

    Aldridge, Bree B.; Russell, David G.

    2014-01-01

    Mycobacterium tuberculosis (Mtb) remains a major public health problem, with an effective vaccine continuing to prove elusive. Progress in vaccination strategies has been hampered by a lack of appreciation of the bacterium's response to dynamic changes in the host immune environment. Here, we utilize reporter Mtb strains that respond to specific host immune stresses such as hypoxia and nitric oxide (hspX′::GFP), and phagosomal maturation (rv2390c′::GFP), to investigate vaccine-induced alterations in the environmental niche during experimental murine infections. While vaccination undoubtedly decreased bacterial burden, we found that it also appeared to accelerate Mtb's adoption of a phenotype better equipped to survive in its host. We subsequently utilized a novel replication reporter strain of Mtb to demonstrate that, in addition to these alterations in host stress response, there is a decreased percentage of actively replicating Mtb in vaccinated hosts. This observation was supported by the differential sensitivity of recovered bacteria to the front-line drug isoniazid. Our study documents the natural history of the impact that vaccination has on Mtb's physiology and replication and highlights the value of reporter Mtb strains for probing heterogeneous Mtb populations in the context of a complex, whole animal model. PMID:25233380

  20. FMD virus isolates: the candidate strains for polyvalent vaccine development in Ethiopia.

    PubMed

    Ayelet, G; Soressa, M; Sisay, T; Belay, A; Gelaye, E; Jembere, S; Skjerve, E; Asmare, K

    2013-06-01

    The study was conducted on foot-and-mouth disease (FMD) viruses with the aim of selecting appropriate vaccinal strain to control of FMD in Ethiopia. The study was conducted in two-dimensional virus neutralization assay to determine the antigenic relationship 'r' value between the candidate vaccine strains and field isolates. A total of 21 serotype O, 7 serotype A, and 8 serotype SAT 2 FMD viruses, which were isolated from cattle and swine. A couple of isolates from each serotype were identified as vaccine candidates in the trial (O-ETH/38/2005, O-ETH/58/2008, A-ETH/7/2008, A-ETH/6/2000, SAT2-ETH/76/2009 and SAT2-ETH/64/2009). The finding revealed all the vaccine candidate depicted high antigenic similarity, above the mean "r" value, to their own serotypes in the studied serotype population except for one serotype A field isolate, A-ETH/13/1981, with "r" value=0.14 and 0.25) which is significantly lower than the minimum requirement. In general, the result indicated that these candidate vaccinal strains can be used for polyvalent vaccine production in the country. PMID:23416124

  1. 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. PMID:26643797

  2. Protection of gruntlings against classical swine fever virus-infection after oral vaccination of sows with C-strain vaccine.

    PubMed

    Kaden, V; Lange, E; Müller, T; Teuffert, J; Teifke, J P; Riebe, R

    2006-12-01

    The objective of this study was to investigate the maternal protection of gruntlings derived from wild sows vaccinated orally against classical swine fever (CSF) using C-strain vaccine. Three vaccinated sows and one unvaccinated control sow were included. Challenge infection of the progeny was carried out either intranasally or by contact at the beginning of the third month of life (61-65 days post-natum). Whereas, two of three litters had maternal antibodies, the progeny of one vaccinated sow was seronegative at challenge. The progeny of the control sow, which was challenged by contact infection, developed moderate clinical signs except for one animal which became ill and died. Two gruntlings derived from the vaccinated sows also died of CSF, although one of them had a relatively high maternal antibody titre (128 ND(50)). The transient infection and partial virus shedding observed in a small number of gruntlings with maternal antibodies and the fact that one animal with maternal antibodies became ill and died confirm the incomplete maternal protection at this age. The reason for this incomplete protection is discussed. As none of the surviving gruntlings could be shown to carry CSFV or viral RNA at the end of the experiment (36 or 70 d.p.i.), it may be concluded that these animals do not represent a potential CSFV reservoir. PMID:17123422

  3. Differentiation of field isolates and vaccine strains of infectious laryngotracheitis virus by DNA sequencing.

    PubMed

    Chacón, Jorge Luis; Ferreira, Antonio J Piantino

    2009-11-12

    Two different regions of the infected cell protein 4 (ICP4) gene of infectious laryngotracheitis virus (ILTV) were amplified and sequenced for characterization of field isolates and tissue culture-origin (TCO) and chicken embryo-origin (CEO) vaccine strains. Phylogenetic analysis of the two regions showed differences in nucleotide and amino acid sequences between field isolates and attenuated vaccines. The PCR-RFLP results were identical to those obtained by DNA sequencing and validated their use to differentiate ILTV strains. The approach using the sequencing of the two fragments of the ICP4 gene showed to be an efficient and practical procedure to differentiate between field isolates and vaccine strains of ILTV. PMID:19747995

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  5. Production of a thermal stress resistant mutant Euglena gracilis strain using Fe-ion beam irradiation.

    PubMed

    Yamada, Koji; Kazama, Yusuke; Mitra, Sharbanee; Marukawa, Yuka; Arashida, Ryo; Abe, Tomoko; Ishikawa, Takahiro; Suzuki, Kengo

    2016-08-01

    Euglena gracilis is a common phytoplankton species, which also has motile flagellate characteristics. Recent research and development has enabled the industrial use of E. gracilis and selective breeding of this species is expected to further expand its application. However, the production of E. gracilis nuclear mutants is difficult because of the robustness of its genome. To establish an efficient mutation induction procedure for E. gracilis, we employed Fe-ion beam irradiation in the RIKEN RI beam factory. A decrease in the survival rate was observed with the increase in irradiation dose, and the upper limit used for E. gracilis selective breeding was around 50 Gy. For a practical trial of Fe-ion irradiation, we conducted a screening to isolate high-temperature-tolerant mutants. The screening yielded mutants that proliferated faster than the wild-type strain at 32 °C. Our results demonstrate the effectiveness of heavy-ion irradiation on E. gracilis selective breeding. PMID:27075598

  6. [Production of a vaccine against enterotoxemia from Clostridium perfringens strains isolated in the field].

    PubMed

    Cherfaoui, S; Kadra, B

    1992-01-01

    We have isolated eight strains of C. perfringens from cases of enterotoxaemia. Five of these strains have revealed themselves toxic with respective types (type "A":2, type "C":2, type "D":1). In order to produce anti-enterotoxaemia vaccine, we have proceeded at the cultivation in fermenter of isolated strains and reference strains CWA 35, CWC and CWD AF. At the end of fermentation, we have evaluated the two following parameters: obtained biomass, and toxin titers. With the two classes of strains we reached an important biomass but toxins titers relatively weak comparatively to that which is usually required. It will be necessary then, to demonstrate the immunogen value of the produced vaccines by testing their efficacity. PMID:1309137

  7. Oral vaccination with microencapsuled strain 19 vaccine confers enhanced protection against Brucella abortus strain 2308 challenge in red deer (Cervus elaphus elaphus).

    PubMed

    Arenas-Gamboa, Angela M; Ficht, Thomas A; Davis, Donald S; Elzer, Philip H; Kahl-McDonagh, Melissa; Wong-Gonzalez, Alfredo; Rice-Ficht, Allison C

    2009-10-01

    Bison (Bison bison) and elk (Cervus elaphus nelsoni) in the Greater Yellowstone Area (GYA), USA, are infected with Brucella abortus, the causative agent of bovine brucellosis, and they serve as a wildlife reservoir for the disease. Bovine brucellosis recently has been transmitted from infected elk to cattle in Montana, Wyoming, and Idaho and has resulted in their loss of brucellosis-free status. An efficacious Brucella vaccine with a delivery system suitable for wildlife would be a valuable tool in a disease prevention and control program. We evaluated Strain 19 (S19) in a sustained release vehicle consisting of alginate microspheres containing live vaccine. In a challenge study using red deer (Cervus elaphus elaphus) as a model for elk, alginate, a naturally occurring polymer combined with a protein of Fasciola hepatica vitelline protein B was used to microencapsulate S19. Red deer were orally or subcutaneously immunized with 1.5 x 10(10) colony-forming units (CFUs) using microencapsulated S19. Humoral and cellular profiles were analyzed bimonthly throughout the study. The vaccinated red deer and nonvaccinated controls were challenged 1 yr postimmunization conjunctivally with 1 x 10(9) CFUs of B. abortus strain 2308. Red deer vaccinated with oral microencapsulated S19 had a statistically significant lower bacterial tissue load compared with controls. These data indicate for the first time that protection against Brucella-challenge can be achieved by combining a commonly used vaccine with a novel oral delivery system such as alginate-vitelline protein B microencapsulation. This system is a potential improvement for efficacious Brucella-vaccine delivery to wildlife in the GYA. PMID:19901378

  8. Development and Characterization of Rifampicin Resistant Flavobacterium Psychrophilum Strains and Their Potential as Live Attenuated Vaccine Candidates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous studies have demonstrated that passage of pathogenic bacteria on increasing concentrations of the antibiotic rifampicin leads to the attenuation of virulence and these resistant strains may serve as live attenuated vaccines. Two rifampicin resistant strains of Flavobacterium psychrophilum,...

  9. Mutants of the Escherichia coli heat-labile enterotoxin as safe and strong adjuvants for intranasal delivery of vaccines.

    PubMed

    Peppoloni, Samuele; Ruggiero, Paolo; Contorni, Mario; Morandi, Maurizio; Pizza, Mariagrazia; Rappuoli, Rino; Podda, Audino; Del Giudice, Giuseppe

    2003-04-01

    Cholera toxin and Escherichia coli heat-labile enterotoxin are powerful mucosal adjuvants but their high toxicity hampers their use in humans. Site-directed mutagenesis has allowed the generation of several cholera toxin and E. coli heat-labile enterotoxin mutants with abolished or strongly reduced toxicity that still retain strong mucosal adjuvanticity. Among them, LTK63 (Ser to Lys substitution at position 63 in the A subunit) is completely nontoxic and LTR72 (Ala to Arg at position 72) retains a very low residual enzymatic activity. Both of them have been shown to be safe and effective in enhancing the immunogenicity of intranasally coadministered vaccines, also resulting in protective responses in several animal models. Clinical grade preparations of these mutants have now been produced, tested in animals and proven to be totally safe. Indeed, they did not induce any inflammatory event in the respiratory tract nor, more importantly, in the olfactory bulbs and in the meninges. The fully nontoxic LTK63 mutant has now been successfully tested in human volunteers with a trivalent subunit influenza vaccine. PMID:12899578

  10. Identification of the pXO1 plasmid in attenuated Bacillus anthracis vaccine strains.

    PubMed

    Liang, Xudong; Zhang, Huijuan; Zhang, Enmin; Wei, Jianchun; Li, Wei; Wang, Bingxiang; Dong, Shulin; Zhu, Jin

    2016-07-01

    Anthrax toxins and capsule are the major virulence factors of Bacillus anthracis. They are encoded by genes located on the plasmids pXO1 and pXO2, respectively. The vaccine strain Pasteur II was produced from high temperature subcultures of B. anthracis, which resulted in virulence attenuation through the loss of the plasmid pXO1. However, it is unclear whether the high temperature culture completely abolishes the plasmid DNA or affects the replication of the plasmid pXO1. In this study, we tested 3 B. anthracis vaccine strains, including Pasteur II from France, Qiankefusiji II from Russia, and Rentian II from Japan, which were all generated from subcultures at high temperatures. Surprisingly, we detected the presence of pXO1 plasmid DNA using overlap PCR in all these vaccine strains. DNA sequencing analysis of overlap PCR products further confirmed the presence of pXO1. Moreover, the expression of the protective antigen (PA) encoded on pXO1 was determined by using SDS-PAGE and western blotting. In addition, we mimicked Pasteur's method and exposed the A16R vaccine strain, which lacks the pXO2 plasmid, to high temperature, and identified the pXO1 plasmid in the subcultures at high temperatures. This indicated that the high temperature treatment at 42.5°C was unable to eliminate pXO1 plasmid DNA from B. anthracis. Our results suggest that the attenuation of the Pasteur II vaccine strain is likely due to the impact of high temperature stress on plasmid replication, which in turn limits the copy number of pXO1. Our data provide new insights into the mechanisms of the remaining immunogenicity and toxicity of the vaccine strains. PMID:27029580

  11. Protection against Helicobacter pylori infection in mice by intragastric vaccination with H. pylori antigens is achieved using a non-toxic mutant of E. coli heat-labile enterotoxin (LT) as adjuvant.

    PubMed

    Marchetti, M; Rossi, M; Giannelli, V; Giuliani, M M; Pizza, M; Censini, S; Covacci, A; Massari, P; Pagliaccia, C; Manetti, R; Telford, J L; Douce, G; Dougan, G; Rappuoli, R; Ghiara, P

    1998-01-01

    We have previously shown that infection of mice with H. pylori can be prevented by oral immunization with H. pylori antigens given together with E. coli heat-labile enterotoxin (LT) as adjuvant. Since LT cannot be used in humans because of its unacceptable toxicity, we investigated whether protection of mice could be achieved by co-administration of antigens with non-toxic LT mutants. Here we show that CD1/SPF mice are protected against infection after oral vaccination with either purified H. pylori antigens (native and recombinant VacA, urease and CagA), or whole-cell vaccine formulations, given together with the non-toxic mutant LTK63 as a mucosal adjuvant. Furthermore we show that such protection is antigen-specific since immunization with recombinant or native VacA plus LTK63 conferred protection against infection by an H. pylori Type I strain, which expresses VacA, but not against challenge with a Type II strain which is not able to express this antigen. These results show that: (1) protection against H. pylori can be achieved in the mouse model of infection using subunit recombinant constructs plus non-toxic mucosal adjuvants; and (2) this mouse model is an useful tool in testing H. pylori vaccine formulations for eventual use in humans. PMID:9607006

  12. Brucella suis strain 2 vaccine is safe and protective against heterologous Brucella spp. infections.

    PubMed

    Zhu, Liangquan; Feng, Yu; Zhang, Ge; Jiang, Hui; Zhang, Zhen; Wang, Nan; Ding, Jiabo; Suo, Xun

    2016-01-12

    Brucellosis is a wide spread zoonotic disease that causes abortion and infertility in mammals and leads to debilitating, febrile illness in humans. Brucella abortus, Brucella melitensis and Brucella suis are the major pathogenic species to humans. Vaccination with live attenuated B. suis strain 2 (S2) vaccine is an essential and critical component in the control of brucellosis in China. The S2 vaccine is very effective in preventing brucellosis in goats, sheep, cattle and swine. However, there are still debates outside of China whether the S2 vaccine is able to provide protection against heterologous virulent Brucella species. We investigated the residual virulence, immunogenicity and protective efficacy of the S2 vaccine in BALB/c mice by determining bacteria persistence in spleen, serum antibody response, cellular immune response and protection against a heterologous virulent challenge. The S2 vaccine was of low virulence as there were no bacteria recovered in spleen four weeks post vaccination. The vaccinated mice developed Brucella-specific IgG in 2-3 weeks, and a burst production of IFN-γ at one week as well as a two-fold increase in TNF-α production. The S2 vaccine protected mice from a virulent challenge by B. melitensis M28, B. abortus 2308 and B. suis S1330, and the S2 vaccinated mice did not develop any clinical signs or tissue damage. Our study demonstrated that the S2 vaccine is of low virulence, stimulates good humoral and cellular immunity and protects animals against infection by heterologous, virulent Brucella species. PMID:26626213

  13. Genetic characterisation of the rabies virus vaccine strains used for oral immunization of foxes in Poland to estimate the effectiveness of vaccination.

    PubMed

    Orłowska, Anna; Żmudziński, Jan Franciszek

    2015-02-01

    The main reservoir of rabies virus in Poland has been the red fox. To control rabies in wildlife, oral immunization of foxes was introduced in 1993. The vaccine is effective when it confers immunity against the virus circulating in the environment. To assess the above issue, a study of the molecular characteristics of 570-bp fragments of the N and G genes of vaccine strains SAD B19 and SAD Bern against street virus strains was performed. The results confirmed the similarity of the vaccine strains and rabies virus strains circulating in the environment and also demonstrate the genetic stability of vaccine strains that have been distributed in Poland for 20 years. PMID:25408374

  14. Assembling flagella in Salmonella mutant strains producing a type III export apparatus without FliO.

    PubMed

    Barker, Clive S; Meshcheryakova, Irina V; Inoue, Tomoharu; Samatey, Fadel A

    2014-12-01

    The type III export apparatus of the Salmonella flagellum consists of six transmembrane proteins (FlhA, FlhB, FliO, FliP, FliQ, and FliR) and three soluble proteins (FliH, FliI, and FliJ). Deletion of the fliO gene creates a mutant strain that is poorly motile; however, suppressor mutations in the fliP gene can partially rescue motility. To further understand the mechanism of suppression of a fliO deletion mutation, we isolated new suppressor mutant strains with partially rescued motility. Whole-genome sequence analysis of these strains found a missense mutation that localized to the clpP gene [clpP(V20F)], which encodes the ClpP subunit of the ClpXP protease, and a synonymous mutation that localized to the fliA gene [fliA(+36T→C)], which encodes the flagellar sigma factor, σ(28). Combining these suppressor mutations with mutations in the fliP gene additively rescued motility and biosynthesis of the flagella in fliO deletion mutant strains. Motility was also rescued by an flgM deletion mutation or by plasmids carrying either the flhDC or fliA gene. The fliA(+36T→C) mutation increased mRNA translation of a fliA'-lacZ gene fusion, and immunoblot analysis revealed that the mutation increased levels of σ(28). Quantitative real-time reverse transcriptase PCR showed that either the clpP(V20F) or fliA(+36T→C) mutation rescued expression of class 3 flagellar and chemotaxis genes; still, the suppressor mutations in the fliP gene had a greater effect on bypassing the loss of fliO function. This suggests that the function of FliO is closely associated with regulation of FliP during assembly of the flagellum. PMID:25201947

  15. A phenotype survey of 36 mutant mouse strains with gene-targeted defects in glycosyltransferases or glycan-binding proteins

    PubMed Central

    Orr, Sally L; Le, Dzung; Long, Jeffrey M; Sobieszczuk, Peter; Ma, Bo; Tian, Hua; Fang, Xiaoqun; Paulson, James C; Marth, Jamey D; Varki, Nissi

    2013-01-01

    The consortium for functional glycomics (CFG) was a large research initiative providing networking and resources for investigators studying the role of glycans and glycan-binding proteins in health and disease. Starting in 2001, six scientific cores were established to generate data, materials and new technologies. By the end of funding in 2011, the mouse phenotype core (MPC) submitted data to a website from the phenotype screen of 36 mutant mouse strains deficient in a gene for either a glycan-binding protein (GBP) or glycosyltransferase (GT). Each mutant strain was allotted three months for analysis and screened by standard phenotype assays used in the fields of immunology, histology, hematology, coagulation, serum chemistry, metabolism and behavior. Twenty of the deficient mouse strains had been studied in other laboratories, and additional tests were performed on these strains to confirm previous observations and discover new data. The CFG constructed 16 new homozygous mutant mouse strains and completed the initial phenotype screen of the majority of these new mutant strains. In total, >300 phenotype changes were observed, but considering the over 100 assays performed on each strain, most of the phenotypes were unchanged. Phenotype differences include abnormal testis morphology in GlcNAcT9- and Siglec-H-deficient mice and lethality in Pomgnt1-deficient mice. The numerous altered phenotypes discovered, along with the consideration of the significant findings of normality, will provide a platform for future characterization to understand the important roles of glycans and GBPs in the mechanisms of health and disease. PMID:23118208

  16. Single-cycle replicable Rift Valley fever virus mutants as safe vaccine candidates.

    PubMed

    Terasaki, Kaori; Tercero, Breanna R; Makino, Shinji

    2016-05-01

    Rift Valley fever virus (RVFV) is an arbovirus circulating between ruminants and mosquitoes to maintain its enzootic cycle. Humans are infected with RVFV through mosquito bites or direct contact with materials of infected animals. The virus causes Rift Valley fever (RVF), which was first recognized in the Great Rift Valley of Kenya in 1931. RVF is characterized by a febrile illness resulting in a high rate of abortions in ruminants and an acute febrile illness, followed by fatal hemorrhagic fever and encephalitis in humans. Initially, the virus was restricted to the eastern region of Africa, but the disease has now spread to southern and western Africa, as well as outside of the African continent, e.g., Madagascar, Saudi Arabia and Yemen. There is a serious concern that the virus may spread to other areas, such as North America and Europe. As vaccination is an effective tool to control RVFV epidemics, formalin-inactivated vaccines and live-attenuated RVFV vaccines have been used in endemic areas. The formalin-inactivated vaccines require boosters for effective protection, whereas the live-attenuated vaccines enable the induction of protective immunity by a single vaccination. However, the use of live-attenuated RVFV vaccines for large human populations having a varied health status is of concern, because of these vaccines' residual neuro-invasiveness and neurovirulence. Recently, novel vaccine candidates have been developed using replication-defective RVFV that can undergo only a single round of replication in infected cells. The single-cycle replicable RVFV does not cause systemic infection in immunized hosts, but enables the conferring of protective immunity. This review summarizes the properties of various RVFV vaccines and recent progress on the development of the single-cycle replicable RVFV vaccines. PMID:26022573

  17. Evaluation of the safety, immunogenicity and efficacy of three capripoxvirus vaccine strains against lumpy skin disease virus.

    PubMed

    Gari, Getachew; Abie, Getnet; Gizaw, Daniel; Wubete, Alehegn; Kidane, Membere; Asgedom, Hagos; Bayissa, Berecha; Ayelet, Gelagay; Oura, Christopher A L; Roger, Francois; Tuppurainen, Eeva S M

    2015-06-22

    The safety, immunogenicity and efficacy of three commercially available vaccines against lumpy skin disease (LSD) in cattle have been evaluated using a combination of vaccine challenge experiments and the monitoring of immune responses in vaccinated animals in the field. The three vaccines evaluated in the study included two locally produced (Ethiopian) vaccines (lumpy skin disease virus (LSDV) Neethling and Kenyan sheep and goat pox (KSGP) O-180 strain vaccines) and a Gorgan goat pox (GTP) vaccine manufactured by Jordan Bio-Industries Centre (JOVAC). The latter vaccine was evaluated for the first time in cattle against LSDV. The Ethiopian Neethling and KSGPO-180 vaccines failed to provide protection in cattle against LSDV, whereas the Gorgan GTP vaccine protected all the vaccinated calves from clinical signs of LSD. There was no significant difference in protective efficacy detected between two dosage levels (P=0.2, P=0.25, and P=0.1 for KSGP, Neethling and Gorgan vaccines, respectively). Additionally, the Gorgan GTP vaccinated cattle showed stronger levels of cellular immune responses measured using Delayed-Type Hypersensitivity (DTH) reactions at the vaccination site indicating higher levels of immunogenicity produced by the GTPV vaccine in cattle, as opposed to the other two vaccines. This study indicated, for the first time, that the Gorgan GTP vaccine can effectively protect cattle against LSDV and that the Neethling and KSGP O-180 vaccine were not protective. The results emphasise the need for molecular characterization of the Neethling and KSGP O-180 vaccine seed viruses used for vaccine production in Ethiopia. In addition, the potency and efficacy testing process of the Ethiopian LSD Neethling and KSGP O-180 vaccines should be re-evaluated. PMID:26056063

  18. Cytokine responses in camels (Camelus bactrianus) vaccinated with Brucella abortus strain 19 vaccine.

    PubMed

    Odbileg, Raadan; Purevtseren, Byambaa; Gantsetseg, Dorj; Boldbaatar, Bazartseren; Buyannemekh, Tumurjav; Galmandakh, Zagd; Erdenebaatar, Janchivdorj; Konnai, Satoru; Onuma, Misao; Ohashi, Kazuhiko

    2008-02-01

    In the present study, we determined the levels of cytokines produced by camel (Camelus bactrianus) peripheral blood mononuclear cells (PBMCs) in response to live attenuated Brucella abortus (B. abortus) S19 vaccine. Seven camels were vaccinated with commercial B. abortus S19 vaccine, and their cytokine responses were determined using a real-time PCR assay. Cytokine responses to B. abortus S19 were examined at 6 hr, 48 hr and 1, 2 and 3 weeks post-vaccination. Serological tests were performed to further confirm these immune responses. The results revealed that IFN-gamma and IL-6 were upregulated during the first week post-vaccination. Low level expressions of IL-1alpha, IL-1beta, TNFalpha and IL-10 and no expression of IL-2 and IL-4 were observed compared with the control camels. The findings showed that B. abortus stimulates cell-mediated immunity by directly activating camel Th1 cells to secrete IFN-gamma. This quantification of cytokine expression in camels is essential for understanding of Camelidae disease development and protective immune responses. This is the first report of in vivo camel cytokine quantification after vaccination. PMID:18319583

  19. Development and Characterization of attenuated Mutant Candidate Vaccines for Control of Paratuberculosis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mycobacterium avium subsp. paratuberculosis (Map) is the causative pathogen of Johne’s disease, a chronic inflammatory wasting disease in ruminants. The disease has been difficult to control because of the lack of an effective vaccine. To develop a live attenuated vaccine for Map, as well as for the...

  20. Recovery of Nonpathogenic Mutant Bacteria from Tumors Caused by Several Agrobacterium tumefaciens Strains: a Frequent Event?▿

    PubMed Central

    Llop, Pablo; Murillo, Jesús; Lastra, Beatriz; López, María M.

    2009-01-01

    We have evaluated the interaction that bacterial genotypes and plant hosts have with the loss of pathogenicity in tumors, using seven Agrobacterium tumefaciens strains inoculated on 12 herbaceous and woody hosts. We performed a screening of the agrobacteria present inside the tumors, looking for nonpathogenic strains, and found a high variability of those strains in this niche. To verify the origin of the putative nonpathogenic mutant bacteria, we applied an efficient, reproducible, and specific randomly amplified polymorphic DNA analysis method. In contrast with previous studies, we recovered a very small percentage (0.01%) of nonpathogenic strains that can be considered true mutants. Of 5,419 agrobacterial isolates examined, 662 were nonpathogenic in tomato, although only 7 (from pepper and tomato tumors induced by two A. tumefaciens strains) could be considered to derive from the inoculated strain. Six mutants were affected in the transferred DNA (T-DNA) region; one of them contained IS426 inserted into the iaaM gene, whereas the whole T-DNA region was apparently deleted in three other mutants, and the virulence of the remaining two mutants was fully restored with the T-DNA genes as well. The plasmid profile was altered in six of the mutants, with changes in the size of the Ti plasmid or other plasmids and/or the acquisition of new plasmids. Our results also suggest that the frequent occurrence of nonpathogenic clones in the tumors is probably due to the preferential growth of nonpathogenic agrobacteria, of either endophytic or environmental origin, but different from the bacterial strain inducing the tumor. PMID:19700547

  1. Genetic Vaccination against Experimental Infection with Myotropic Parasite Strains of Trypanosoma cruzi

    PubMed Central

    Araújo, Adriano Fernando; de Oliveira, Gabriel; Vasconcelos, Juliana Fraga; Ersching, Jonatan; Dominguez, Mariana Ribeiro; Vasconcelos, José Ronnie; Machado, Alexandre Vieira; Gazzinelli, Ricardo Tostes; Bruna-Romero, Oscar; Soares, Milena Botelho; Rodrigues, Mauricio Martins

    2014-01-01

    In earlier studies, we reported that a heterologous prime-boost regimen using recombinant plasmid DNA followed by replication-defective adenovirus vector, both containing Trypanosoma cruzi genes encoding trans-sialidase (TS) and amastigote surface protein (ASP) 2, provided protective immunity against experimental infection with a reticulotropic strain of this human protozoan parasite. Herein, we tested the outcome of genetic vaccination of F1 (CB10XBALB/c) mice challenged with myotropic parasite strains (Brazil and Colombian). Initially, we determined that the coadministration during priming of a DNA plasmid containing the murine IL-12 gene improved the immune response and was essential for protective immunity elicited by the heterologous prime-boost regimen in susceptible male mice against acute lethal infections with these parasites. The prophylactic or therapeutic vaccination of resistant female mice led to a drastic reduction in the number of inflammatory infiltrates in cardiac and skeletal muscles during the chronic phase of infection with either strain. Analysis of the electrocardiographic parameters showed that prophylactic vaccination reduced the frequencies of sinus arrhythmia and atrioventricular block. Our results confirmed that prophylactic vaccination using the TS and ASP-2 genes benefits the host against acute and chronic pathologies caused by T. cruzi and should be further evaluated for the development of a veterinary or human vaccine against Chagas disease. PMID:25061263

  2. [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. PMID:7541494

  3. Whole genome analyses of G1P[8] rotavirus strains from vaccinated and non-vaccinated South African children presenting with diarrhea.

    PubMed

    Magagula, Nonkululeko B; Esona, Mathew D; Nyaga, Martin M; Stucker, Karla M; Halpin, Rebecca A; Stockwell, Timothy B; Seheri, Mapaseka L; Steele, A Duncan; Wentworth, David E; Mphahlele, M Jeffrey

    2015-01-01

    Group A rotaviruses (RVAs) are the leading cause of severe gastroenteritis and eventually death among infants and young children worldwide, and disease prevention and management through vaccination is a public health priority. In August 2009, Rotarix™ was introduced in the South African Expanded Programme on Immunisation. As a result, substantial reductions in RVA disease burden have been reported among children younger than 5 years old. Rotavirus strain surveillance post-vaccination is crucial to, inter alia, monitor and study the evolution of vaccine escape strains. Here, full-genome sequence data for the 11 gene segments from 11 South African G1P[8] rotavirus strains were generated, including 5 strains collected from non-vaccinated children during the 2004-2009 rotavirus seasons and 6 strains collected from vaccinated children during the 2010 rotavirus season. These data were analyzed to gain insights into the overall genetic makeup and evolution of South African G1P[8] rotavirus strains and to compare their genetic backbones with those of common human Wa-like RVAs from other countries, as well as with the Rotarix™ and RotaTeq™ G1P[8] vaccine components. All 11 South African G1P[8] strains revealed a complete Wa-like genotype constellation of G1-P[8]-I1-R1-C1-M1-A1-N1-T1-E1-H1. On the basis of sequence similarities, the South African G1P[8] strains (with the exception of strain RVA/Human-wt/ZAF/1262/2004/G1P[8]) were closely related to each other (96-100% identity in all gene segments). Comparison to the Rotarix™ and RotaTeq™ G1P[8] vaccine components revealed a moderate nucleotide identity of 89-96% and 93-95%, respectively. The results indicated that none of the gene segments of these 11 South African G1P[8] strains were vaccine-derived. This study illustrates that large-scale next generation sequencing will provide crucial information on the influence of the vaccination program on evolution of rotavirus strains. This is the first report to describe

  4. Intact immune defenses are required for mice to resist the ts-4 vaccine strain of Toxoplasma gondii.

    PubMed Central

    Sayles, P C; Johnson, L L

    1996-01-01

    The ts-4 strain of Toxoplasma gondii is a temperature-sensitive mutant that fails to grow at 40 degrees C in vitro. Unlike mildly virulent cyst-forming strains, which can cause fatal chronic infections in certain mouse strains, ts-4 has been widely used to vaccinate mice against virulent T. gondii and is a valuable tool with which to investigate mechanisms of acquired resistance to this parasite. In this report, the basis for the avirulence of ts-4 is analyzed. It is shown that ts-4 is able to persist long-term in vivo in mildly immunocompromised mice, which rules out an intrinsic growth defect as a reason for avirulence. ts-4 does not induce body temperatures in mice as high as that needed to kill it in vitro. Moreover, the mild fevers elicited in resistant B6 mice are also seen in susceptible C57BL/6 scid/scid mice. However, ts-4 elicits strong preimmune defenses, dependent on gamma interferon, which are needed by mice to survive acute infection. Furthermore, CD4+ and CD8+ T-cell-dependent acquired immunity is essential for long-term survival of ts-4-infected mice. PMID:8757838

  5. 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.

  6. [Evaluation of the vaccine potentiality of 2 strains from Leptospira interrogans serogroup Ballum].

    PubMed

    Rodríguez, Andrés González; Jiménez, Yoandra Rodríguez; Santiesteban, Niurka Batista; Abreu, Yolanda Valdés; Osenes, Juan Francisco Núñez; González, Marta González

    2005-01-01

    Two vacine candidate strains from Ballum serogroup were characterized and their immunogenicity and protective power were studied in hamster. The monovalent vaccine formulations obtained showed a high immunogenicity and capacity of homologous protection and, in a lesser degree, of cross protection. PMID:17966485

  7. Some guidelines for determining foot-and-mouth disease vaccine strain matching by serology.

    PubMed

    Mattion, Nora; Goris, Nesya; Willems, Tom; Robiolo, Blanca; Maradei, Eduardo; Beascoechea, Claudia Perez; Perez, Alejandro; Smitsaart, Eliana; Fondevila, Norberto; Palma, Eduardo; De Clercq, Kris; La Torre, José

    2009-01-29

    The selection of matching strains for use in outbreaks of foot-and-mouth disease (FMD) virus can be assessed in vivo or by serological r-value determination. Sera from animals involved in vaccine potency and cross-protection trials performed using the "Protection against Podal Generalization" (PPG) test for two serotype A strains were collected and analyzed by the virus neutralization test (VNT) and liquid-phase ELISA (lpELISA) in three laboratories. The average VNT r-values for medium and high serum titer classes from the A(24) Cruzeiro vaccinated animals were in line with the A/Arg/01 heterologous PPG outcome for all testing laboratories, suggesting that the vaccine strain A(24) Cruzeiro is unlikely to protect against the field isolate A/Arg/01. The corresponding lpELISA r-values were slightly higher and indicate a closer relationship between both strains. Pooling of serum samples significantly reduced the inter-animal and inter-trial variation. The results suggest that a suitable reference serum for vaccine matching r-value experiments might be a pool or a medium to high VNT or lpELISA titer serum. Furthermore, the VNT seems to produce the most reproducible inter-laboratory results. More work is, however, needed in order to substantiate these claims. PMID:19041355

  8. Draft Genome Sequence of the Vaccination Strain Mycobacterium bovis BCG S4-Jena.

    PubMed

    Wibberg, Daniel; Winkler, Anika; Straube, Eberhard; Karrasch, Matthias; Keller, Peter M; Kalinowski, Jörn

    2016-01-01

    Here, we present the draft genome sequence of ITALIC! Mycobacterium bovisBCG S4-Jena, a tuberculosis vaccine strain. The genome of S4-Jena is represented by 48 scaffolds, consisting of 132 scaffolded contigs and amounting to a size of about 4.2 Mb. New genes potentially encoding a phage fragment were identified in the genome. PMID:27103721

  9. Draft Genome Sequence of the Vaccination Strain Mycobacterium bovis BCG S4-Jena

    PubMed Central

    Wibberg, Daniel; Winkler, Anika; Straube, Eberhard; Karrasch, Matthias; Keller, Peter M.

    2016-01-01

    Here, we present the draft genome sequence of Mycobacterium bovis BCG S4-Jena, a tuberculosis vaccine strain. The genome of S4-Jena is represented by 48 scaffolds, consisting of 132 scaffolded contigs and amounting to a size of about 4.2 Mb. New genes potentially encoding a phage fragment were identified in the genome. PMID:27103721

  10. Rapid generation of pandemic influenza virus vaccine candidate strains using synthetic DNA

    PubMed Central

    Verity, Erin E.; Camuglia, Sarina; Agius, Catherine T.; Ong, Chi; Shaw, Robert; Barr, Ian; Middleton, Deborah; Rockman, Steven

    2011-01-01

    Please cite this paper as: Verity et al. (2011) Rapid generation of pandemic influenza virus vaccine candidate strains using synthetic DNA. Influenza and Other Respiratory Viruses DOI:10.1111/j.1750‐2659.2011.00273.x. Background  Vaccination is considered the most effective means of reducing influenza burden. The emergence of H5N1 and pandemic spread of novel H1N1/2009 viruses reinforces the need to have strategies in place to rapidly develop seed viruses for vaccine manufacture. Methods  Candidate pandemic vaccine strains consisting of the circulating strain haemagglutinin (HA) and neuraminidase (NA) in an A/PR/8/34 backbone were generated using alternative synthetic DNA approaches, including site‐directed mutagenesis of DNA encoding related virus strains, and rapid generation of virus using synthetic DNA cloned into plasmid vectors. Results  Firstly, synthetic A/Bar Headed Goose/Qinghai/1A/2005 (H5N1) virus was generated from an A/Vietnam/1194/2004 template using site‐directed mutagenesis. Secondly, A/Whooper Swan/Mongolia/244/2005 (H5N1) and A/California/04/09 (H1N1) viruses were generated using synthetic DNA encoding the viral HA and NA genes. Replication and antigenicity of the synthetic viruses were comparable to that of the corresponding non‐synthetic viruses. Conclusions  In the event of an influenza pandemic, the use of these approaches may significantly reduce the time required to generate and distribute the vaccine seed virus and vaccine manufacture. These approaches also offer the advantage of not needing to handle wild‐type virus, potentially diminishing biocontainment requirements. PMID:21771285

  11. Isolation, characterization and biological activities of verotetrone from a mutant strain of Streptomyces aureofaciens.

    PubMed

    Prikrylová, V; Podojil, M; Hilgert, I; Fuska, J; Vokoun, J; Vanĕk, Z

    1980-01-01

    A new metabolite denoted as verotetrone was isolated from the mycelium of the mutant strain Streptomyces aureofaciens NMG-2. Interpretations of physical data concerning verotetrone and its triacetate and, the determination of its degradation product indicate that verotetrone belongs to pretetramide-type metabolites. Verotetrone exhibits neither antibacterial nor antifungal activity. In vitro it inhibits the synthesis of nucleic acids as well as proteins in Ehrlich ascites carcinoma cells. Both verotetrone and its triacetate interfere in vivo with the metabolism of tumour and lymphoid cells, exhibiting antitumour or immunosuppressive activity. This activity, which is more intense with verotetrone than with its triacetate, is detectable in a dose which is already toxic in some animals. PMID:6774935

  12. 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. PMID:24195347

  13. Degradation of p-chlorotoluene by a mutant of Pseudomonas sp. strain JS6

    SciTech Connect

    Haigler, B.E.; Spain, J.C. )

    1989-02-01

    Pseudomonas sp. strain JS6 grows on chlorobenzene, p-dichlorobenzene, or toluene as a sole source of carbon and energy. It does not grow on p-chlorotoluene (p-CT). Growth on glucose in the presence of p-CT resulted in the accumulation of 4-chloro-2,3- dihydroxy-1-methyl benzene (3-chloro-6- methylcatechol), 4-chloro- 2,3-dihydroxy-1-methyl cyclohexa- 4,6-diene (p-CT dihydrodoil), and 2-methyl-4-carboxy methylenebut-2-en-4-olide (2-methyl dienelactone). Strain JS21, a spontaneous mutant capable of growth on p-CT, was isolated from cultures of strain JS6 after extended exposure to p-CT. In addition to growing on p-CT, JS21 grew on all of the substrates that supported growth of the parent strain, including p-dichlorobenzene, chlorobenzene, benzene, toluene, benzoate, p-hydroxybenzoate, phenol, and ethylbenzene. The pathway for degradation of p-CT by JS21 was investigated by respirometry, isolation of intermediates, and assay of enzymes in cell extracts. p-CT was converted to 3-chloro-6-methylcatechol by dioxygenase and dihydrodiol dehydrogenase enzymes. 3-Chloro-6-methylcatechol underwent ortho ring cleavage catalyzed by a catechol 1,2-dioxygenase to form 2-chloro-5-methyl-cis,cis-muconate, which was converted to 2-methyl dienelactone. A dienelactone hydrolase converted 2-methyl dienelactone to 2-methylmaleylacetic acid. Preliminary results indicate that a change in wild-type induction patterns allows JS21 to grow on p-CT.

  14. Clostridium perfringens epsilon toxin mutant Y30A-Y196A as a recombinant vaccine candidate against enterotoxemia.

    PubMed

    Bokori-Brown, Monika; Hall, Charlotte A; Vance, Charlotte; Fernandes da Costa, Sérgio P; Savva, Christos G; Naylor, Claire E; Cole, Ambrose R; Basak, Ajit K; Moss, David S; Titball, Richard W

    2014-05-13

    Epsilon toxin (Etx) is a β-pore-forming toxin produced by Clostridium perfringens toxinotypes B and D and plays a key role in the pathogenesis of enterotoxemia, a severe, often fatal disease of ruminants that causes significant economic losses to the farming industry worldwide. This study aimed to determine the potential of a site-directed mutant of Etx (Y30A-Y196A) to be exploited as a recombinant vaccine against enterotoxemia. Replacement of Y30 and Y196 with alanine generated a stable variant of Etx with significantly reduced cell binding and cytotoxic activities in MDCK.2 cells relative to wild type toxin (>430-fold increase in CT50) and Y30A-Y196A was inactive in mice after intraperitoneal administration of trypsin activated toxin at 1000× the expected LD50 dose of trypsin activated wild type toxin. Moreover, polyclonal antibody raised in rabbits against Y30A-Y196A provided protection against wild type toxin in an in vitro neutralisation assay. These data suggest that Y30A-Y196A mutant could form the basis of an improved recombinant vaccine against enterotoxemia. PMID:24709588

  15. Clostridium perfringens epsilon toxin mutant Y30A-Y196A as a recombinant vaccine candidate against enterotoxemia

    PubMed Central

    Bokori-Brown, Monika; Hall, Charlotte A.; Vance, Charlotte; Fernandes da Costa, Sérgio P.; Savva, Christos G.; Naylor, Claire E.; Cole, Ambrose R.; Basak, Ajit K.; Moss, David S.; Titball, Richard W.

    2014-01-01

    Epsilon toxin (Etx) is a β-pore-forming toxin produced by Clostridium perfringens toxinotypes B and D and plays a key role in the pathogenesis of enterotoxemia, a severe, often fatal disease of ruminants that causes significant economic losses to the farming industry worldwide. This study aimed to determine the potential of a site-directed mutant of Etx (Y30A-Y196A) to be exploited as a recombinant vaccine against enterotoxemia. Replacement of Y30 and Y196 with alanine generated a stable variant of Etx with significantly reduced cell binding and cytotoxic activities in MDCK.2 cells relative to wild type toxin (>430-fold increase in CT50) and Y30A-Y196A was inactive in mice after intraperitoneal administration of trypsin activated toxin at 1000× the expected LD50 dose of trypsin activated wild type toxin. Moreover, polyclonal antibody raised in rabbits against Y30A-Y196A provided protection against wild type toxin in an in vitro neutralisation assay. These data suggest that Y30A-Y196A mutant could form the basis of an improved recombinant vaccine against enterotoxemia. PMID:24709588

  16. 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. PMID:26460745

  17. 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

  18. 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. PMID:27068833

  19. Induced drought tolerance through wild and mutant bacterial strain Pseudomonas simiae in mung bean (Vigna radiata L.).

    PubMed

    Kumari, Sarita; Vaishnav, Anukool; Jain, Shekhar; Varma, Ajit; Choudhary, Devendra Kumar

    2016-01-01

    The present study focused on the overproducing mutant of a plant growth promoting rhizobacterium (PGPR) Pseudomonas simiae strain AU (MTCC-12057) for significant drought tolerance in mung bean plants. Five mutants namely AU-M1, AU-M2, AU-M3, AU-M4 and AU-M5 were made after treatment of wild type strain with N-methyl-N-nitro-N-nitrosoguanidine. Mutant strain AU-M4 was recorded for enhanced ACC deaminase (ACC-D) activity, indole acetic acid (IAA) production and inorganic phosphate (Pi) solubilization compared to wild strain and other four mutant strains under drought condition. AU-M4 showed higher phosphate solubilization index (8.17) together with higher ACC-D activity (98 nmol/mg/h) and IAA concentration (69.35 µg/ml) compared with the wild type P. simiae strain AU ACC-D activity (79 nmol/mg/h) and IAA concentration (38.98 µg/ml) respectively. In this report, we investigated the effect of both wild and mutant type bacterial strain on mung bean plants under drought stress. Results showed that mutant AU-M4 and wild type strain AU inoculated plants exhibited superior tolerance against drought stress, as shown by their enhanced plant biomass (fresh weight), higher water content, higher proline accumulation and lower osmotic stress injury. Mutant AU-M4 and wild strain AU inoculated plants reduced the ethylene level by 59 and 45% respectively, compared to the control under stress condition. Furthermore, bacterial inoculated plants showed enhanced induced systemic drought tolerance by reducing stomata size and net photosynthesis resulting higher water content in mung bean plants that may help in survival of plants during drought condition. To mitigate the effects of drought stress, use of PGPR will be needed to ensure sufficient production of food from crop plants. Taking current leads available, concerted future research is needed in this area, particularly on field evaluation with application of potential microorganisms. PMID:26712619

  20. Production in Vero cells of an inactivated rabies vaccine from strain FRV/K for animal and human use.

    PubMed

    el-Karamany, R M

    1987-08-01

    A new concentrated and purified rabies vaccine was produced in Vero cells. Two rabies virus strains, the fixed rabies virus Pasteur (FRV) and Pittman Moore (PM) were adapted to Vero cells by 20 cycles of alternating passages in the brain of weaning mice. Intracerebral (i.c.) inoculation of weaning mice was followed then by 17 and 20 serial passages in Vero cells of RFV and PM strains, respectively. The adapted strains designated as FRV/K and PM/K gave titres of 10(6) +/- 1.5 log (LD50/ml for i.c. inoculated mice) in several harvests taken from one infected cell culture. Pooled harvests were concentrated 20-fold by ultrafiltration and were tested as animal vaccine after inactivation with beta-propiolactone (BPL). Another vaccine preparation destined for human use, in addition to concentration and inactivation, was also purified by gel filtration. Control tests revealed that the antigenic content of different strain FRV/K harvests was very high in comparison with that of strain PM/K and the reference tissue culture vaccine (RIV, Netherland). In sheep the antibody response induced by the FRV/K strain was very high; serum neutralizing index (NI) higher than 4 was reached 40 days after the second vaccine dose, whereas the vaccine preparation from strain PM/K gave NI of 2.3 and the reference vaccine NI of 3.8, respectively. Safety tests in rabbits and guinea pigs showed neither pyrogenicity nor toxicity. PMID:2892381

  1. Propagation of the Israeli vaccine strain of Anaplasma centrale in tick cell lines

    PubMed Central

    Bell-Sakyi, Lesley; Palomar, Ana M.; Bradford, Emma L.; Shkap, Varda

    2015-01-01

    Anaplasma centrale has been used in cattle as a live blood vaccine against the more pathogenic Anaplasma marginale for over 100 years. While A. marginale can be propagated in vitro in tick cell lines, facilitating studies on antigen production, immunisation and vector-pathogen interaction, to date there has been no in vitro culture system for A. centrale. In the present study, 25 cell lines derived from 13 ixodid tick species were inoculated with the Israeli vaccine strain of A. centrale and monitored for at least 12 weeks by microscopic examination of Giemsa-stained cytocentrifuge smears. Infection of 19 tick cell lines was subsequently attempted by transfer of cell-free supernate from vaccine-inoculated tick cells. In two separate experiments, rickettsial inclusions were detected in cultures of the Rhipicephalus appendiculatus cell line RAE25 28–32 days following inoculation with the vaccine. Presence of A. centrale in the RAE25 cells was confirmed by PCR assays targeting the 16S rRNA, groEL and msp4 genes; sequenced PCR products were 100% identical to published sequences of the respective genes in the Israeli vaccine strain of A. centrale. A. centrale was taken through three subcultures in RAE25 cells over a 30 week period. In a single experiment, the Dermacentor variabilis cell line DVE1 was also detectably infected with A. centrale 11 weeks after inoculation with the vaccine. Availability of an in vitro culture system for A. centrale in tick cells opens up the possibility of generating a safer and more ethical vaccine for bovine anaplasmosis. PMID:26210950

  2. Propagation of the Israeli vaccine strain of Anaplasma centrale in tick cell lines.

    PubMed

    Bell-Sakyi, Lesley; Palomar, Ana M; Bradford, Emma L; Shkap, Varda

    2015-09-30

    Anaplasma centrale has been used in cattle as a live blood vaccine against the more pathogenic Anaplasma marginale for over 100 years. While A. marginale can be propagated in vitro in tick cell lines, facilitating studies on antigen production, immunisation and vector-pathogen interaction, to date there has been no in vitro culture system for A. centrale. In the present study, 25 cell lines derived from 13 ixodid tick species were inoculated with the Israeli vaccine strain of A. centrale and monitored for at least 12 weeks by microscopic examination of Giemsa-stained cytocentrifuge smears. Infection of 19 tick cell lines was subsequently attempted by transfer of cell-free supernate from vaccine-inoculated tick cells. In two separate experiments, rickettsial inclusions were detected in cultures of the Rhipicephalus appendiculatus cell line RAE25 28-32 days following inoculation with the vaccine. Presence of A. centrale in the RAE25 cells was confirmed by PCR assays targeting the 16S rRNA, groEL and msp4 genes; sequenced PCR products were 100% identical to published sequences of the respective genes in the Israeli vaccine strain of A. centrale. A. centrale was taken through three subcultures in RAE25 cells over a 30 week period. In a single experiment, the Dermacentor variabilis cell line DVE1 was also detectably infected with A. centrale 11 weeks after inoculation with the vaccine. Availability of an in vitro culture system for A. centrale in tick cells opens up the possibility of generating a safer and more ethical vaccine for bovine anaplasmosis. PMID:26210950

  3. 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. PMID:25904510

  4. Phage-resistant mutants of Lactobacillus delbrueckii may have functional properties that differ from those of parent strains.

    PubMed

    Vinderola, Gabriel; Marcó, Mariángeles Briggiler; Guglielmotti, Daniela M; Perdigón, Gabriela; Giraffa, Giorgio; Reinheimer, Jorge; Quiberoni, Andrea

    2007-05-01

    Three commercial phage sensitive Lactobacillus delbrueckii strains (identified as Ab(1), YSD V and Ib(3)), and four spontaneous phage-resistant mutants isolated from them were tested for their capacity to activate the gut mucosal immune response in mice, as indicated by the numbers of IgA-producing cells. Random Amplified Polymorphic DNA (RAPD) analysis revealed a strong genetic homology between the sensitive strains and their respective derivatives. The phage-resistant mutants exhibited high levels of phage resistance, elevated stability of this phenotype and technological properties comparable to those of their respective parent strains. The tolerance to acidic conditions, bile salts and lysozyme was strain dependent and total cell viability losses as a result of exposure to all three stresses ranged from 2.0 to 3.7 log units. All the strains were highly resistant to a simulated gastric solution of pH 3, while significant additional losses in cell viability were observed when acid treated cells were exposed to bile salts and lysozyme. BALB/c mice received pure cultures of Lb. delbrueckii sensitive and phage-resistant strains for 2, 5 or 7 consecutive days. The ability of the parent strains to activate the small intestine immune response was preserved or enhanced in phage-resistant mutants. The maximal proliferation of IgA(+) cells was observed at day 5 or 7, depending on the strain. Mutants isolated in this study using natural selection strategies had improved phage resistance, adequate technological properties and satisfactory gut mucosal immunostimulation ability, and so would be good candidates for industrial applications in functional foods. PMID:17307269

  5. Enhancing cellulase production by overexpression of xylanase regulator protein gene, xlnR, in Talaromyces cellulolyticus cellulase hyperproducing mutant strain.

    PubMed

    Okuda, Naoyuki; Fujii, Tatsuya; Inoue, Hiroyuki; Ishikawa, Kazuhiko; Hoshino, Tamotsu

    2016-10-01

    We obtained strains with the xylanase regulator gene, xlnR, overexpressed (HXlnR) and disrupted (DXlnR) derived from Talaromyces cellulolyticus strain C-1, which is a cellulase hyperproducing mutant. Filter paper degrading enzyme activity and cellobiohydrolase I gene expression was the highest in HXlnR, followed by C-1 and DXlnR. These results indicate that the enhancement of cellulase productivity was succeeded by xlnR overexpression. PMID:27309759

  6. Differential Immune Responses and Protective Effects in Avirulent Mycobacterial Strains Vaccinated BALB/c Mice.

    PubMed

    Liu, Laicheng; Fu, Ruiling; Yuan, Xuefeng; Shi, Chunwei; Wang, Shuling; Lu, Xianyu; Ma, Zhao; Zhang, Xiaoming; Qin, Weiyan; Fan, Xionglin

    2015-07-01

    Screening live mycobacterial vaccine candidates is the important strategy to develop new vaccines against adult tuberculosis (TB). In this study, the immunogenicity and protective efficacy of several avirulent mycobacterial strains including Mycobacterium smegmatis, M. vaccae, M. terrae, M. phlei, M. trivial, and M. tuberculosis H37Ra were compared with M. bovis BCG in BALB/c mice. Our results demonstrated that differential immune responses were induced in different mycobacterial species vaccinated mice. As BCG-vaccinated mice did, M. terrae immunization resulted in Th1-type responses in the lung, as well as splenocytes secreting IFN-γ against a highly conserved mycobacterial antigen Ag85A. M. smegmatis also induced the same splenocytes secreting IFN-γ as BCG and M. terrae did. In addition, M. terrae and M. smegmatis-immunized mice predominantly increased expression of IL-10 and TGF-β in the lung. Most importantly, mice vaccinated with H37Ra and M. vaccae could provide the same protection in the lung against virulent M. tuberculosis challenge as BCG. The result may have important implications in developing adult TB vaccine. PMID:25995039

  7. A short-filament mutant of Anabaena sp. strain PCC 7120 that fragments in nitrogen-deficient medium.

    PubMed Central

    Bauer, C C; Buikema, W J; Black, K; Haselkorn, R

    1995-01-01

    Strain 129 is a fragmentation mutant of the filamentous cyanobacterium Anabaena sp. strain PCC 7120. Growing with fixed nitrogen, this mutant forms filaments that are much shorter than wild-type filaments. Following starvation for fixed nitrogen, strain 129 becomes nearly unicellular and forms few heterocysts, although electron microscopy suggests that proheterocysts form while fragmentation occurs. Starvation for sulfate, phosphate, iron, and calcium does not cause this fragmentation. The affected gene in strain 129, fraC, was cloned by complementation and characterized. It encodes a unique 179-amino-acid protein rich in phenylalanine. Insertional inactivation of the chromosomal copy of fraC results in a phenotype identical to that of strain 129, while complementation using a truncated version of FraC results in only partial complementation of the original mutant. Heterocysts could be induced to form in N-replete cultures of strain 129, as in wild-type cells, by supplying extra copies of the hetR gene on a plasmid. Thus, FraC is required for the integrity of cell junctions in general but is apparently not directly involved in normal differentiation and nitrogen fixation. PMID:7883709

  8. [Selected research problems of anthrax vaccine development].

    PubMed

    Zakowska, Dorota; Kocik, Janusz; Bartoszcze, Michał

    2009-01-01

    The threat of bioterrorism with B. anthracis against civilian population is one of major concern. After successful bioterroristic attack in 2001 in US renewed research interest has prompted in the development of new and more effective vaccine against anthrax. There are two licensed vaccines against anthrax--AVA-Bio-Thrax US and UK--sterile culture filtrate prepared by alum precipitation. Both vaccines are based on PA antigen. There are several concerns regarding PA based vaccines. They require six sc injections and yearly booster, high rates of local reaction after vaccination is observed, the immunity is not long lasting, vaccination do not protect animals against different strains of B. anthracis. New strategies in the development of anthrax vaccines have been presented (recombinant PA, subunits vaccine, mutants, conjugated). Using proteomic approaches new antigens have been also identified as candidates for future vaccines. More effective and easy to perform methods of vaccination have been reviewed. PMID:20120948

  9. Altered calmodulin activity in fluphenazine-resistant mutant strains. Pleiotropic effect on development and cellular organization in Volvox carteri.

    PubMed

    Kurn, N; Sela, B A

    1981-12-01

    Genetically altered calmodulin activity in spontaneously derived mutant strains, which were selected for resistance to the toxic effect of a specific inhibitor, the phenothiazine drug fluphenazine, is demonstrated. Partially purified calmodulin preparations from wild-type and fluphenazine-resistant strains of the multicellular alga Volvox carteri, were tested for the ability to activate Ca2+-ATPase of the erythrocyte membranes, and the inhibition of this stimulatory activity by fluphenazine. Unlike the preparation obtained from wild-type cells, mutant calmodulin is shown to be insensitive to fluphenazine inhibition, in one case, and calmodulin from another strain was found to be inactive in vitro, i.e. it did not activate Ca2+-ATPase. The pleiotropic phenotype of the spontaneously derived mutant strains involved aberrant multicellular organization and hormone-independent commitment of the multipotent asexual reproductive cells, gonodia, to sexual development. These results clearly implicate calmodulin in the control of development and morphogenesis in this simple multicellular eukaryote. In addition, intracellular inhibition of calmodulin in wild-type cells is shown to block the morphogenic process of embryo inversion and to arrest motility. The availability of mutant calmodulin will facilitate further investigation of the role of this ubiquitous regulatory protein in the control of development and differentiation in multicellular eukarytes, as well as the fine structure/function relationship with regard to calmodulin modulation of a wide variety of cellular processes. PMID:6459931

  10. In vivo and in vitro genetic recombination between conventional and gene-deleted vaccine strains of pseudorabies virus.

    PubMed

    Henderson, L M; Katz, J B; Erickson, G A; Mayfield, J E

    1990-10-01

    Pseudorabies virus (PRV), an alpha-herpesvirus, causes substantial economic losses in the swine industry and is currently the focus of eradication and control programs. Some of these programs rely on the ability of veterinarians to differentiate animals exposed to virulent strains of PRV from animals exposed to avirulent vaccine strains of PRV on the basis of a serologic response to nonessential glycoproteins that are deleted in some vaccine strains of PRV. Genetic recombination resulting in the creation of virulent strains of PRV with the same negative immunologic markers as vaccine strains could disrupt these programs. Two strains of PRV were coinoculated either into tissue culture or into sheep to facilitate recombination. Progeny viruses were selected to detect a specific recombinant phenotype. We were able to detect genetic recombination between vaccine strains of PRV following in vitro or in vivo coinoculation of 2 strains of PRV. The selected recombinants had marker-deleted phenotypes in strains with restored virulence genes. Increased virulence was observed in sheep after coinoculation of 2 avirulent vaccine strains of PRV. PMID:2173449