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Texas A&M University
1.
Zriba, Slim.
Towards the Development of an Improved Vaccine for Swine Against Brucellosis.
Degree: MS, Biomedical Sciences, 2017, Texas A&M University
URL: http://hdl.handle.net/1969.1/161643 
► Swine brucellosis is a zoonotic disease with variable incidence rates in domestic and feral populations. It is a serious public health issue due to the…
(more)
▼ Swine brucellosis is a zoonotic disease with variable incidence rates in domestic and feral populations. It is a serious public health issue due to the potential for spillover not only between infected feral and domestic swine but also cattle and humans. Previous studies published by our laboratory has demonstrated the cross-protective immunity elicited by the S19ΔvjbR live attenuated vaccine in mice against challenge with B. abortus, B. melitensis or B. suis, suggesting its potential use as a vaccine against multiple Brucella species. To date there is no effective vaccine used to prevent brucellosis in swine. This prompted us to study the potential use of S19 ΔvjbR as a vaccine candidate in this natural host by evaluating its safety and humoral response in pregnant swine. Fifteen pregnant gilts at fifty days of gestation (midgestation) were divided into four groups and vaccinated subcutaneously with 1X10
10 CFU of either; 1) strain S19; 2) S19ΔvjbR encapsulated in alginate microspheres 3) unencapsulated S19ΔvjbR, or 4) empty capsules as a control. Interestingly, none of the animals vaccinated with either S19 or S19ΔvjbR aborted or demonstrated any adverse side effect associated with vaccination. No bacteria was recovered from any of the tissues examined supporting the lack of histopathological changes in major organs either in piglets or in gilts. Vaginal swab culture from vaccinated animals showed no bacterial growth on Farrell’s agar medium. RBT and IgG iELISA tests were found substantial at 2 week (k= 0.8) and 4 week (k=0.65) post-vaccination suggesting that RBT can be used during this interval as a good tool to confirm the immunization of animals with the different vaccine strains. Different responses of gilts sera against purified vjbR protein at pre-vaccination and two week post-vaccination raised the question of specificity of the vjbR as marker and its inability to validate DIVA capabilities of the ΔvjbR vaccine candidates.
Advisors/Committee Members: Arenas, Angela (advisor), Ficht, Thomas A. (committee member), Welsh, C. Jane (committee member).
Subjects/Keywords: Abortion; brucellosis; vaccination; iELISA; Western blot; Rose Bengal Test; DIVA; ΔvjbR
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APA (6th Edition):
Zriba, S. (2017). Towards the Development of an Improved Vaccine for Swine Against Brucellosis. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/161643
Chicago Manual of Style (16th Edition):
Zriba, Slim. “Towards the Development of an Improved Vaccine for Swine Against Brucellosis.” 2017. Masters Thesis, Texas A&M University. Accessed February 27, 2021.
http://hdl.handle.net/1969.1/161643.
MLA Handbook (7th Edition):
Zriba, Slim. “Towards the Development of an Improved Vaccine for Swine Against Brucellosis.” 2017. Web. 27 Feb 2021.
Vancouver:
Zriba S. Towards the Development of an Improved Vaccine for Swine Against Brucellosis. [Internet] [Masters thesis]. Texas A&M University; 2017. [cited 2021 Feb 27].
Available from: http://hdl.handle.net/1969.1/161643.
Council of Science Editors:
Zriba S. Towards the Development of an Improved Vaccine for Swine Against Brucellosis. [Masters Thesis]. Texas A&M University; 2017. Available from: http://hdl.handle.net/1969.1/161643
Texas A&M University
2.
Gomez, Gabriel.
Identification and Evaluation of Brucella Recombinant Outer Membrane Proteins as Subunit Vaccinogen Candidates in the Mouse Model of Brucellosis.
Degree: PhD, Veterinary Pathology, 2013, Texas A&M University
URL: http://hdl.handle.net/1969.1/149282
► Despite being amongst the most common zoonotic diseases in the world, brucellosis is a neglected disease for which an approved vaccine for human use does…
(more)
▼ Despite being amongst the most common zoonotic diseases in the world, brucellosis is a neglected disease for which an approved vaccine for human use does not exist. Thus far, the traditional approaches to Brucella antigen selection for subunit vaccine development have yielded unacceptable results. In this work, we evaluated the predictive ability of a multistep Brucella antigen selection process with in vitro immunological and invasion assays and in vivo protection experiments. Initial in silico screening for antigens was performed via genomic sequence analysis where 27 Brucella melitensis open reading frames (ORF) coding for outer membrane proteins bearing MHC epitopes, adhesin and conserved properties were identified. Evidence for a role in any aspect of Brucella virulence (i.e., invasion, co-regulation/expression with known Brucella virulence factors, intracellular adaptation) was then used to narrow the list of candidate antigens. To further increase confidence in the candidate ORF putative role in Brucella pathogenesis, differential expression of candidate ORF was evaluated using previously generated global transcriptomics data in in vitro HeLa and in vivo bovine models of acute Brucella infection.
Protein expression in the E. coli heterologous system resulted in the successful expression of OmpW, BtuB, Omp22, Hia, and FlgK. With regards to virulence, the two proteins with the highest predicted adhesin scores conferred an invasive phenotype to the non-invasive BL-21 E. coli strain in alveolar epithelial cells. From an immunogenicity standpoint, all proteins elicited IgG production in Brucella-exposed goats, mouse and humans. Antigen-specific recall responses in splenocytes from C57BL/6 mice immunized with a cocktail of the three proteins with highest MHC scores revealed a mixed Th1/Th2 response with a comparatively greater Th1 response. In protection studies, subcutaneous (SQ) immunization with BtuB, Hia and FlgK, individually, promoted bacterial clearance following a robust intraperitoneal challenge dose of Brucella melitensis 16M. In addition, single SQ inoculation of FlgK enhanced protective efficacy of the vaccine strain B. abortus S19. In contrast, immunization of mice with the three protective antigens in a cocktail formulation elicited immune responses but no protection against intraperitoneal challenge with Brucella melitensis 16M in the spleen and liver. In conclusion, our results indicate that our combinatorial in silico, in vitro and in vivo antigen selection and identification modeling approach provides strong evidence for prediction of Brucella protective antigens, and represent a novel strategy with broad application to other major pathogens.
Advisors/Committee Members: Ficht, Thomas A (advisor), Adams, Leslie G (advisor), Mwangi, Waithaka (committee member), Burghardt, Robert (committee member).
Subjects/Keywords: Brucella; outer membrane proteins; vaccine; antigens; reverse vaccinology; mouse
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APA (6th Edition):
Gomez, G. (2013). Identification and Evaluation of Brucella Recombinant Outer Membrane Proteins as Subunit Vaccinogen Candidates in the Mouse Model of Brucellosis. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/149282
Chicago Manual of Style (16th Edition):
Gomez, Gabriel. “Identification and Evaluation of Brucella Recombinant Outer Membrane Proteins as Subunit Vaccinogen Candidates in the Mouse Model of Brucellosis.” 2013. Doctoral Dissertation, Texas A&M University. Accessed February 27, 2021.
http://hdl.handle.net/1969.1/149282.
MLA Handbook (7th Edition):
Gomez, Gabriel. “Identification and Evaluation of Brucella Recombinant Outer Membrane Proteins as Subunit Vaccinogen Candidates in the Mouse Model of Brucellosis.” 2013. Web. 27 Feb 2021.
Vancouver:
Gomez G. Identification and Evaluation of Brucella Recombinant Outer Membrane Proteins as Subunit Vaccinogen Candidates in the Mouse Model of Brucellosis. [Internet] [Doctoral dissertation]. Texas A&M University; 2013. [cited 2021 Feb 27].
Available from: http://hdl.handle.net/1969.1/149282.
Council of Science Editors:
Gomez G. Identification and Evaluation of Brucella Recombinant Outer Membrane Proteins as Subunit Vaccinogen Candidates in the Mouse Model of Brucellosis. [Doctoral Dissertation]. Texas A&M University; 2013. Available from: http://hdl.handle.net/1969.1/149282
Texas A&M University
3.
Akoolo, Lavoisier.
Role of Brucella Toll/Interleukin-1 Receptor (TIR) Domain Containing Protein (∆TcpB) Deletion Mutant in Protective Immunity against Brucellosis.
Degree: PhD, Veterinary Microbiology, 2015, Texas A&M University
URL: http://hdl.handle.net/1969.1/155602
► Brucellosis is an important zoonotic disease affecting about 500,000 people annually. The development of safer and more efficacious Brucella Live attenuated vaccines addresses safety concerns…
(more)
▼ Brucellosis is an important zoonotic disease affecting about 500,000 people annually. The development of safer and more efficacious Brucella Live attenuated vaccines addresses safety concerns that include the identification of reproducible and reliable surrogates of protection and mechanisms to bolster longevity. Brucella encodes a toll interleukin receptor domain containing protein (TcpB/Btp-1). These proteins subvert host innate immunity by abrogating NF-κB mediated cytokine production, by binding to and/or causing the degradation of signaling molecules TIRAP (MAL) and MyD88. TcpB has also been shown to directly reduce the CTL killing activity of infected host cells. In the current study, we investigated the effect of deleting tcpB from Brucella on invitro and invivo immune responses. We also evaluated an in vitro murine Brucella growth inhibition co-culture assay to determine the capacity of immune splenocytes from mice exposed to the tcpB mutant or wild type to control the growth of Brucella melitensis in murine bone marrow derived macrophages. A tcpB knockout constructed by gene replacement in the Brucella abortus S19 genetic background was used to vaccinate C57BL/6 mice assessed for development of CD4+ memory T cells. Mice vaccinated with the mutant displayed an elevated Th1 response, compared to the parental S19 and non- vaccinated controls, as manifested by multiple factors. These include; elevated IFN-γ early post vaccination, and a significant elevation of memory CD4+CD44+CD62L+ within CD4+T cell population in splenocytes derived from mice vaccinated with the mutant. S19 and S19ΔtcpB strains induced a significant increase in the IgG2a levels post vaccination. Consistent with a shift to a Th1 response, S19ΔtcpB induced a higher response later in vaccination. Splenocytes obtained from mice vaccinated with the S19ΔtcpB mutant exhibited significantly higher levels of killing activity compared to cells derived from S19 vaccinated mice and PBS controls. Consistent with enhanced immune protection, fewer bacteria were recovered from the spleens of mice vaccinated with the S19ΔtcpB mutant, which had reduced inflammatory lesions consistent with reduced bacterial burden. These results provide strong evidence that tcpB deletion improves immunogenicity, longevity and protective efficacy of S19 and that ex vivo co- cultivation may be employed to predict potential vaccine efficacy.
Advisors/Committee Members: Ficht, Thomas A (advisor), Adams, Garry L (committee member), McMurray, David N (committee member), Zhu, Guan (committee member).
Subjects/Keywords: Brucella; Toll interleukin-1 receptor domain containing protein; Immunity; vaccine
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APA (6th Edition):
Akoolo, L. (2015). Role of Brucella Toll/Interleukin-1 Receptor (TIR) Domain Containing Protein (∆TcpB) Deletion Mutant in Protective Immunity against Brucellosis. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/155602
Chicago Manual of Style (16th Edition):
Akoolo, Lavoisier. “Role of Brucella Toll/Interleukin-1 Receptor (TIR) Domain Containing Protein (∆TcpB) Deletion Mutant in Protective Immunity against Brucellosis.” 2015. Doctoral Dissertation, Texas A&M University. Accessed February 27, 2021.
http://hdl.handle.net/1969.1/155602.
MLA Handbook (7th Edition):
Akoolo, Lavoisier. “Role of Brucella Toll/Interleukin-1 Receptor (TIR) Domain Containing Protein (∆TcpB) Deletion Mutant in Protective Immunity against Brucellosis.” 2015. Web. 27 Feb 2021.
Vancouver:
Akoolo L. Role of Brucella Toll/Interleukin-1 Receptor (TIR) Domain Containing Protein (∆TcpB) Deletion Mutant in Protective Immunity against Brucellosis. [Internet] [Doctoral dissertation]. Texas A&M University; 2015. [cited 2021 Feb 27].
Available from: http://hdl.handle.net/1969.1/155602.
Council of Science Editors:
Akoolo L. Role of Brucella Toll/Interleukin-1 Receptor (TIR) Domain Containing Protein (∆TcpB) Deletion Mutant in Protective Immunity against Brucellosis. [Doctoral Dissertation]. Texas A&M University; 2015. Available from: http://hdl.handle.net/1969.1/155602
4.
Weeks, Jenni Nichole.
Identification of genetic loci and transcriptional networks that confer virulence and survival of Brucella melitensis.
Degree: PhD, Genetics, 2009, Texas A&M University
URL: http://hdl.handle.net/1969.1/ETD-TAMU-2970
► Brucella melitensis is the etiological agent of brucellosis, a zoonotic disease characterized by abortions in ruminant animals and a chronic debilitating disease in humans. Despite…
(more)
▼ Brucella melitensis is the etiological agent of brucellosis, a zoonotic
disease characterized by abortions in ruminant animals and a chronic
debilitating disease in humans. Despite genome sequencing, little is known
about the genetic elements behind Brucellas ability to survive and cause
disease. Regulatory networks provide the ability to adapt to changing
environments by initiating expression from specific regulons to provide
adjustments to metabolism and mechanisms that enhance survival. Little detail
is known about transcriptional networks that exist in Brucella, but are of great
interest because they could provide information about genetic loci that contribute
to virulence and intracellular survival.
Transposon mutagenesis identified gene loci that are indispensable for
the intracellular replication of B. melitensis, including virulence genes, metabolic
defects, and transcriptional regulators. Two transcriptional regulators of interest
were identified, MucR and VjbR. VjbR is a LuxR homologue and is associated with the regulation of virulence genes in a density dependent manner in a
number of bacterial pathogens, and is consistent with VjbR regulation of
virulence genes in B. melitensis. Microarray analysis of vjbR and a potential
activating signal C12-HSL revealed that both regulate numerous putative
virulence genes, including adhesins, proteases, protein secretion/translocation
components, potential effector proteins, lipoproteins, a hemolysin and stress
survival aids. This analysis also revealed that C12-HSL is not an activating signal
of VjbR, but instead acts to suppress VjbR activity.
MucR is a transcriptional regulator shown to regulate exopolysaccharide
synthesis in the closely related Rhizobiales. Microarray analysis of a mucR
mutant in B. melitensis suggested that MucR contributes to the regulation of
nitrogen metabolism and iron sequestering/storage. MucR was also found to
regulate genes involved in stress response, regulating several proteases that
may contribute to enhanced survival and virulence of the organism.
This work identified approximately 1,000 genetic loci that may be
important to the survival of B. melitensis, revealing potential virulence genes and
metabolic defects. Interruption of the VjbR regulon could be a potential
chemotherapeutic target for the treatment of brucellosis. Furthermore, this work
describes the functions of two gene deletions that are being evaluated as novel
attenuated vaccines.
Advisors/Committee Members: Ficht, Thomas A (advisor), McMurray, David N (committee member), Samuel, James E (committee member), Siegele, Deborah A (committee member).
Subjects/Keywords: Brucella melitensis; gene regulation
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APA (6th Edition):
Weeks, J. N. (2009). Identification of genetic loci and transcriptional networks that confer virulence and survival of Brucella melitensis. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2970
Chicago Manual of Style (16th Edition):
Weeks, Jenni Nichole. “Identification of genetic loci and transcriptional networks that confer virulence and survival of Brucella melitensis.” 2009. Doctoral Dissertation, Texas A&M University. Accessed February 27, 2021.
http://hdl.handle.net/1969.1/ETD-TAMU-2970.
MLA Handbook (7th Edition):
Weeks, Jenni Nichole. “Identification of genetic loci and transcriptional networks that confer virulence and survival of Brucella melitensis.” 2009. Web. 27 Feb 2021.
Vancouver:
Weeks JN. Identification of genetic loci and transcriptional networks that confer virulence and survival of Brucella melitensis. [Internet] [Doctoral dissertation]. Texas A&M University; 2009. [cited 2021 Feb 27].
Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2970.
Council of Science Editors:
Weeks JN. Identification of genetic loci and transcriptional networks that confer virulence and survival of Brucella melitensis. [Doctoral Dissertation]. Texas A&M University; 2009. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2970
Texas A&M University
5.
Turse, Joshua Edward.
Concerning Brucella LPS: genetic analysis and role in host- agent interaction.
Degree: PhD, Genetics, 2006, Texas A&M University
URL: http://hdl.handle.net/1969.1/4442
► B rucella lipopolysaccharide is an important component of virulence in brucellosis. Recent research in macrophage models has shown that Brucella LPS does not behave like…
(more)
▼ B rucella lipopolysaccharide is an important component of virulence in
brucellosis. Recent research in macrophage models has shown that Brucella
LPS does not behave like classical LPS by stimulating potent inflammatory
responses. The central hypothesis of this work is that O-antigen is dynamic
signaling molecular and participates in complex interactions with the host to
promote productive infection. A corollary to this is that the host environment is
dynamic, and Brucella has evolved mechanisms to cope with changing
environments. In an effort to understand the contribution of Brucella LPS to
virulence and pathogenesis, the function of a metabolic locus important in the
synthesis of LPS has been demonstrated and complemented. The spontaneous
loss of LPS expression has been characterized. Contribution of LPS to
acquisition of the host environment in tissue culture and mouse models has
been explored. This work demonstrated that genes outside the O-antigen
biosynthesis ( manBA) cluster contribute to LPS biosynthesis. Further high frequency mutation involving manBA is partly responsible for observed
dissociation of Brucella strains. Finally, work herein attempts to look at the role
of LPS in acquisition of the host environment and shows that LPS is important
for recruiting particular cell populations within a host model of brucellosis.
Advisors/Committee Members: Ficht, Thomas A. (advisor), Samuel, James (committee member), Skare, Jon (committee member), Tsolis, Ren (committee member).
Subjects/Keywords: Brucella; Lipopolysaccharide; Innate immunity; bacterial mutation; Luria-Delbr
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APA (6th Edition):
Turse, J. E. (2006). Concerning Brucella LPS: genetic analysis and role in host- agent interaction. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/4442
Chicago Manual of Style (16th Edition):
Turse, Joshua Edward. “Concerning Brucella LPS: genetic analysis and role in host- agent interaction.” 2006. Doctoral Dissertation, Texas A&M University. Accessed February 27, 2021.
http://hdl.handle.net/1969.1/4442.
MLA Handbook (7th Edition):
Turse, Joshua Edward. “Concerning Brucella LPS: genetic analysis and role in host- agent interaction.” 2006. Web. 27 Feb 2021.
Vancouver:
Turse JE. Concerning Brucella LPS: genetic analysis and role in host- agent interaction. [Internet] [Doctoral dissertation]. Texas A&M University; 2006. [cited 2021 Feb 27].
Available from: http://hdl.handle.net/1969.1/4442.
Council of Science Editors:
Turse JE. Concerning Brucella LPS: genetic analysis and role in host- agent interaction. [Doctoral Dissertation]. Texas A&M University; 2006. Available from: http://hdl.handle.net/1969.1/4442
Texas A&M University
6.
Arenas Gamboa, Angela Maria.
Evaluation of microencapsulation as an improved vaccination strategy against brucellosis.
Degree: PhD, Veterinary Microbiology, 2009, Texas A&M University
URL: http://hdl.handle.net/1969.1/ETD-TAMU-1384
► Brucellosis is an important zoonotic disease of nearly worldwide distribution. Despite the availability of live vaccine strains for bovine (S19, RB51) and small ruminants (Rev…
(more)
▼ Brucellosis is an important zoonotic disease of nearly worldwide distribution.
Despite the availability of live vaccine strains for bovine (S19, RB51) and small
ruminants (Rev 1), these vaccines have several drawbacks including residual virulence
for animals and humans. Safe and efficacious immunization systems are therefore
needed to overcome these disadvantages. Brucella melitensis and Brucella abortus
mutants in the luxR gene were generated and investigated for theri potential use as
improve vaccine candidates. Immunization with a sustained release vehicle to enhance
vaccination efficacy was evaluated utilizing the live mutants in encapsulated alginate
microspheres containing a non-immunogenic eggshell precursor protein of the parasite
Fasciola hepatica (Vitelline protein B, VpB). BALB/c mice were immunized with either
encapsulated or nonencapsulated vaccine candidates to evaluate immunogenicity,
safety and protective efficacy. The results suggest that luxR mutants, are attenuated in
the mouse and macrophage model and appear good and safe vaccine candidates when
the immunogen is given in a microencapsulated format. We were also able to
demonstrate the utility of microencapsulation in oral delivery by increasing vaccine
performance of current licensed vaccine strains in a natural host, the Red Deer. Together, these results suggest that microencapsulation of live Brucella
produces an enhanced delivery vaccine system against brucellosis increasing the
efficacy of poorly-performing nonencapsulated vaccine candidates.
Advisors/Committee Members: Rice Ficht, Allison (advisor), Ficht, Thomas A (advisor), Mwangi, Waithaka (committee member), Welsh, C Jane (committee member).
Subjects/Keywords: Brucella; Microencapsulation
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APA (6th Edition):
Arenas Gamboa, A. M. (2009). Evaluation of microencapsulation as an improved vaccination strategy against brucellosis. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-1384
Chicago Manual of Style (16th Edition):
Arenas Gamboa, Angela Maria. “Evaluation of microencapsulation as an improved vaccination strategy against brucellosis.” 2009. Doctoral Dissertation, Texas A&M University. Accessed February 27, 2021.
http://hdl.handle.net/1969.1/ETD-TAMU-1384.
MLA Handbook (7th Edition):
Arenas Gamboa, Angela Maria. “Evaluation of microencapsulation as an improved vaccination strategy against brucellosis.” 2009. Web. 27 Feb 2021.
Vancouver:
Arenas Gamboa AM. Evaluation of microencapsulation as an improved vaccination strategy against brucellosis. [Internet] [Doctoral dissertation]. Texas A&M University; 2009. [cited 2021 Feb 27].
Available from: http://hdl.handle.net/1969.1/ETD-TAMU-1384.
Council of Science Editors:
Arenas Gamboa AM. Evaluation of microencapsulation as an improved vaccination strategy against brucellosis. [Doctoral Dissertation]. Texas A&M University; 2009. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-1384
Texas A&M University
7.
Bain, Sherrie Valarie.
An unknown regulator affects cell division and the timing of entry into stationary phase in Escherichia coli.
Degree: MS, Microbiology, 2005, Texas A&M University
URL: http://hdl.handle.net/1969.1/2356
► When an essential nutrient is depleted from the medium, cultures of wildtype E. coli cells enter a period called stationary phase. The transition into stationary…
(more)
▼ When an essential nutrient is depleted from the medium, cultures of wildtype
E. coli cells enter a period called stationary phase. The transition into
stationary phase is marked by distinct changes in cell physiology, gene
expression, and morphology. Pr???? and Matsumura (18) found a mutant strain of
E. coli that was able to continue growing exponentially at a time when wild-type
cells had stopped growing and entered stationary phase. They concluded that
FlhD, a transcriptional activator of flagellar genes, was responsible for this
growth phenotype and that it is a regulator of cell division (17, 18). Contrary to
the findings of Pr???? and Matsumura, research in our lab has shown that the
mutant growth phenotype observed in the strain used by Matsumura and Pr???? is
flhD independent. This study sought to identify the second mutation, which we
call cdr (cell division regulator) in the strain used by Matsumura and Pr????. We
used Hfr mapping and P1 transduction to localize the mutation to a specific
region of the chromosome. We also sought to determine if this growth
phenotype was due to loss of function or gain of function and whether the
mutation in the cdr gene was sufficient to cause the observed growth phenotype
in other strain backgrounds. In addition the growth phenotype of these two
strains was compared to that of other wild-type and standard laboratory E. coli
strains. Our results indicate that the cdr mutation is located in the 88.5. region of
the chromosome and is due to loss of Cdr function. We also discovered that the
growth phenotype assigned to the mutant strain more closely reflects that of
other wild-type laboratory strains as did the morphology of cells in stationary
phase. This evidence suggests that the actual mutant strain might be the one
that was designated as the wild-type strain by Matsumura and Pr???? and both
strains may contain mutations that actually cause a decrease in cell number
instead of an increase as previously reported.
Advisors/Committee Members: Siegele, Deborah A. (advisor), Ficht, Thomas A. (committee member), Garcia, Rene L. (committee member), Sweet, Merrill (committee member).
Subjects/Keywords: Unknown; regulator
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APA (6th Edition):
Bain, S. V. (2005). An unknown regulator affects cell division and the timing of entry into stationary phase in Escherichia coli. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/2356
Chicago Manual of Style (16th Edition):
Bain, Sherrie Valarie. “An unknown regulator affects cell division and the timing of entry into stationary phase in Escherichia coli.” 2005. Masters Thesis, Texas A&M University. Accessed February 27, 2021.
http://hdl.handle.net/1969.1/2356.
MLA Handbook (7th Edition):
Bain, Sherrie Valarie. “An unknown regulator affects cell division and the timing of entry into stationary phase in Escherichia coli.” 2005. Web. 27 Feb 2021.
Vancouver:
Bain SV. An unknown regulator affects cell division and the timing of entry into stationary phase in Escherichia coli. [Internet] [Masters thesis]. Texas A&M University; 2005. [cited 2021 Feb 27].
Available from: http://hdl.handle.net/1969.1/2356.
Council of Science Editors:
Bain SV. An unknown regulator affects cell division and the timing of entry into stationary phase in Escherichia coli. [Masters Thesis]. Texas A&M University; 2005. Available from: http://hdl.handle.net/1969.1/2356
Texas A&M University
8.
Kahl, Melissa Marie.
Evaluation of unmarked deletion mutants as improved Brucella vaccine strains in the mouse and goat models.
Degree: PhD, Veterinary Microbiology, 2006, Texas A&M University
URL: http://hdl.handle.net/1969.1/4197
► Historical data suggests that prolonged survival of Brucella vaccine organisms in the target host enhances immune protection. Recent research has focused upon the development of…
(more)
▼ Historical data suggests that prolonged survival of Brucella vaccine organisms in
the target host enhances immune protection. Recent research has focused upon the
development of rough vaccine strains to avoid interference with standard diagnostic
tests. Rough organisms are rapidly cleared from the host, however. In an effort to
develop improved vaccine strains, we have screened signature tagged mutagenesis banks
to identify mutants with varying survival characteristics. We hypothesize that in order
for a vaccine to be efficacious, it must survive in the host. In order to test this, we
constructed marked and unmarked deletion mutants of B. abortus and B. melitensis in
genes previously demonstrated by transposon mutagenesis to attenuate in vivo and in
vitro virulence. Survival and efficacy of these novel deletion mutants were then
evaluated in the mouse model. The asp24 mutants, which persist for extended periods in
vivo, appear superior as a vaccine candidate compared to approved vaccine strains S19
and Rev1 in the mouse model against either homologous or heterologous challenges.
Once enhanced protection against infection was demonstrated in the mouse, components
of immune function that appeared to be most important were identified to correlate the
immune response with the observed protection. We demonstrated that the most persistent mutant, delta-asp24, affords the greatest protection in mice against virulent
challenge. In order to evaluate safety of the novel vaccine strains as well as protection
against infection and abortion, we tested selected B. melitensis unmarked deletion
mutants in a natural host, the goat. The delta-asp24 mutant was shown to be safe in pregnant
goats while providing significant protection against infection and abortion.
Advisors/Committee Members: Ficht, Thomas A. (advisor), Adams, L. Garry (committee member), Davis, Donald S. (committee member), Tsolis, Renee M. (committee member).
Subjects/Keywords: Brucella; vaccine
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APA (6th Edition):
Kahl, M. M. (2006). Evaluation of unmarked deletion mutants as improved Brucella vaccine strains in the mouse and goat models. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/4197
Chicago Manual of Style (16th Edition):
Kahl, Melissa Marie. “Evaluation of unmarked deletion mutants as improved Brucella vaccine strains in the mouse and goat models.” 2006. Doctoral Dissertation, Texas A&M University. Accessed February 27, 2021.
http://hdl.handle.net/1969.1/4197.
MLA Handbook (7th Edition):
Kahl, Melissa Marie. “Evaluation of unmarked deletion mutants as improved Brucella vaccine strains in the mouse and goat models.” 2006. Web. 27 Feb 2021.
Vancouver:
Kahl MM. Evaluation of unmarked deletion mutants as improved Brucella vaccine strains in the mouse and goat models. [Internet] [Doctoral dissertation]. Texas A&M University; 2006. [cited 2021 Feb 27].
Available from: http://hdl.handle.net/1969.1/4197.
Council of Science Editors:
Kahl MM. Evaluation of unmarked deletion mutants as improved Brucella vaccine strains in the mouse and goat models. [Doctoral Dissertation]. Texas A&M University; 2006. Available from: http://hdl.handle.net/1969.1/4197
Texas A&M University
9.
Gull, Tamara Brownsey.
In vivo infection biology of contagious bovine pleuropneumonia.
Degree: PhD, Veterinary Microbiology, 2009, Texas A&M University
URL: http://hdl.handle.net/1969.1/ETD-TAMU-2611
► Contagious Bovine Pleuropneumonia (CBPP), caused by Mycoplasma mycoides mycoides small colony (MmmSC), is a devastating respiratory disease of cattle in Africa, Asia and the Middle…
(more)
▼ Contagious Bovine Pleuropneumonia (CBPP), caused by Mycoplasma mycoides
mycoides small colony (MmmSC), is a devastating respiratory disease of cattle in Africa,
Asia and the Middle East. Little investigation has been done on molecular disease
pathogenesis and host response beyond soluble cytokine detection. This study developed
and characterized models for three strains of MmmSC of varying severity. Strains used
were Gladysdale, Ondangwa and Shawawa. Samples of bronchoalveolar lavage fluid,
bronchial biopsy, nasal epithelial cells and blood were obtained prior to and at weekly
time points post-infection. Microarray analysis of RNA extracted from samples revealed
host cellular pathways and genes important in the pathogenesis of CBPP, including
multiple immune system and inflammatory response pathways. A number of pathways
whose influence on disease pathogenesis was not immediately clear were also activated,
including pathways involved in amino acid synthesis, fat metabolism, and endocrine
hormone responses. Microarray results were confirmed with real-time polymerase chain
reaction (RT-PCR) of selected genes. Comparative RT-PCR analysis of selected genes between the three strains of MmmSC revealed genes possibly responsible for differential
strain virulence, including interleukins 1B, 6, 8, and 18 and the gene nuclear factor of
kappa light polypeptide gene enhancer in B cells inhibitor, alpha (NFKBIA). A similar
analysis of selected genes between survivors and nonsurvivors of the virulent Gladysdale
strain of MmmSC suggested genes involved in survival, including interleukin 8,
calmodulin 2 (CALM2), and NFKBIA. Avenues of additional study were identified.
Advisors/Committee Members: Adams, L. Garry (advisor), Ficht, Thomas A. (committee member), Geary, Steven J. (committee member), Welsh, C. Jane (committee member), Womack, James (committee member).
Subjects/Keywords: Contagious Bovine Pleuropneumonia; Mycoplasma mycoides mycoides small colony; cattle; infectious disease; foreign animal disease
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APA ·
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MLA ·
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CSE |
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to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Gull, T. B. (2009). In vivo infection biology of contagious bovine pleuropneumonia. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2611
Chicago Manual of Style (16th Edition):
Gull, Tamara Brownsey. “In vivo infection biology of contagious bovine pleuropneumonia.” 2009. Doctoral Dissertation, Texas A&M University. Accessed February 27, 2021.
http://hdl.handle.net/1969.1/ETD-TAMU-2611.
MLA Handbook (7th Edition):
Gull, Tamara Brownsey. “In vivo infection biology of contagious bovine pleuropneumonia.” 2009. Web. 27 Feb 2021.
Vancouver:
Gull TB. In vivo infection biology of contagious bovine pleuropneumonia. [Internet] [Doctoral dissertation]. Texas A&M University; 2009. [cited 2021 Feb 27].
Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2611.
Council of Science Editors:
Gull TB. In vivo infection biology of contagious bovine pleuropneumonia. [Doctoral Dissertation]. Texas A&M University; 2009. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2611
Texas A&M University
10.
Hong, Priscilla Christine.
Utilization of the persistent nature of Brucella in the development of live vaccines.
Degree: PhD, Microbiology, 2006, Texas A&M University
URL: http://hdl.handle.net/1969.1/4163
► The roles of genes responsible for the survival and persistence of Brucella in the host and the relationship between these genes and the disease were…
(more)
▼ The roles of genes responsible for the survival and persistence of Brucella in the
host and the relationship between these genes and the disease were investigated via
signature-tagged transposon mutagenesis. As much as 8% of the Brucella genome is
important for survival of this organism in the host. This is an unusually high number
and may help to explain the chronic or persistent nature of Brucella infections. Mutants
attenuated in the mouse model were divided into two groups. The early mutants failed
to establish infection or colonize the host. The late mutants colonized the host but failed
to maintain infection. The vaccine potential of two mutants (virB10 and gcvH) that were
unable to sustain infection was compared to that of a vaccine strain, S19. Survival of
strain S19 in vivo was up to 12 weeks while virB10 and gcvH mutants were cleared from
spleen at 8, and 24 weeks post-inoculation, respectively. Mice were vaccinated with
individual mutants and then challenged with virulent S2308 at 8, 16, and 24 weeks postvaccination.
As a result, protective immunity correlated with persistence of the mutant
strain [gcvH>virB10]. These results suggest that survival is one of several factors that may influence
protective immunity making it difficult to compare strains. For example, examination of
host immune response revealed a similar pattern of host immune function (TH1 over
TH2) in all mice except those vaccinated with virB10 mutant. Since gcvH mutant
provided the best immunity, experiments were designed to explore its contribution of
persistence to protection. In an effort to reduce non-specific activation induced by
prolonged survival of gcvH mutant, protection was monitored after different periods of
vaccination exposure followed with doxycycline treatment. In these studies, persistence
of gcvH mutant enhanced protection against challenge. Overall, defined mutations in
genes affecting survival may render mutants as vaccine candidates capable of
stimulating protective immunity equal to or better than fortuitously isolated attenuated
strains. Future studies should focus on characterization of these and other genes
responsible for the persistence of Brucella to improve the safety and efficacy of live
vaccines.
Advisors/Committee Members: Ficht, Thomas A., Samuel, James E., Skare, Jon T., (advisor), Samuel, James E. (committee member), Skare, Jon T. (committee member), Welsh, Jane C. (committee member).
Subjects/Keywords: Brucella; Brucella abortus; chronic; persistence; mouse; macrophage
Record Details
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APA ·
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APA (6th Edition):
Hong, P. C. (2006). Utilization of the persistent nature of Brucella in the development of live vaccines. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/4163
Chicago Manual of Style (16th Edition):
Hong, Priscilla Christine. “Utilization of the persistent nature of Brucella in the development of live vaccines.” 2006. Doctoral Dissertation, Texas A&M University. Accessed February 27, 2021.
http://hdl.handle.net/1969.1/4163.
MLA Handbook (7th Edition):
Hong, Priscilla Christine. “Utilization of the persistent nature of Brucella in the development of live vaccines.” 2006. Web. 27 Feb 2021.
Vancouver:
Hong PC. Utilization of the persistent nature of Brucella in the development of live vaccines. [Internet] [Doctoral dissertation]. Texas A&M University; 2006. [cited 2021 Feb 27].
Available from: http://hdl.handle.net/1969.1/4163.
Council of Science Editors:
Hong PC. Utilization of the persistent nature of Brucella in the development of live vaccines. [Doctoral Dissertation]. Texas A&M University; 2006. Available from: http://hdl.handle.net/1969.1/4163
Texas A&M University
11.
Suchodolski, Jan S.
Assessment of the canine intestinal microflora using molecular methods and serum markers.
Degree: PhD, Veterinary Microbiology, 2007, Texas A&M University
URL: http://hdl.handle.net/1969.1/4696
► Previous studies examining the canine intestinal microflora have focused on cultivation of bacteria from intestinal content. Recently, it has been recognized that the majority of…
(more)
▼ Previous studies examining the canine intestinal microflora have focused on
cultivation of bacteria from intestinal content. Recently, it has been recognized that the
majority of bacteria cannot be identified using standard culture techniques. The aim of
this study was to describe the composition and dynamics of the canine intestinal
microflora using molecular methods based on identification of the 16S ribosomal DNA
(16S rDNA) and to evaluate the clinical use of a 13C-glycocholic acid blood test (13CGCBT)
as a serum marker for small intestinal bacterial biomass. Intestinal content was
obtained from healthy dogs and the microflora was characterized in different
compartments of each dog by denaturing gradient gel electrophoresis (DGGE) and
comparative 16S rDNA analysis. A 13C-glycocholic acid blood test (13C-GCBT) was
developed as a marker for small intestinal bacterial biomass and the influence of tylosin
administration on the 13C-GCBT, serum concentrations of cobalamin, folate, and
unconjugated cholic acid (SUCA) was evaluated. There was marked variation in DGGE
profiles between individual dogs and also between different intestinal compartments
within dogs. DGGE profiles from duodenal juice samples collected endoscopically at
different time-points varied within individuals, possibly due to variations over time or a
slight variation in sampling location. Direct sequencing revealed 106 individual 16S
rDNA sequences. Forty-two sequences showed less than 98% similarity to described
sequences in public databases and may constitute previously uncharacterized bacterial species. Serum folate concentrations, SUCA, and the cumulative percent dose/min of 13C
administered as 13C-glycocholic acid (CUMPCD) increased significantly following
tylosin administration (p<0.01). The results indicate that dogs have a complex intestinal
microflora with marked differences between individual dogs. Different intestinal
compartments appear to host a unique microflora and the assessment of a fecal sample
does not yield accurate information about the composition of the microflora in proximal
compartments of the gut. The intestine harbors many previously uncharacterized
bacterial species. The clinical significance of these uncharacterized intestinal bacterial
species needs to be further investigated in dogs with gastrointestinal disease. Increased
serum folate, SUCA, and CUMPCD in the 13C-GCBT suggest that, in the dogs described
here, tylosin administration increased the biomass of organisms carrying out these
metabolic functions.
Advisors/Committee Members: Wagner, Gale G. (advisor), Williams, David A. (advisor), Buddington, Randal K. (committee member), Ficht, Thomas A. (committee member), Steiner, J (committee member).
Subjects/Keywords: canine; gastrointestinal tract; microflora; DNA fingerprinting
Record Details
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APA ·
Chicago ·
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CSE |
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Manager
APA (6th Edition):
Suchodolski, J. S. (2007). Assessment of the canine intestinal microflora using molecular methods and serum markers. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/4696
Chicago Manual of Style (16th Edition):
Suchodolski, Jan S. “Assessment of the canine intestinal microflora using molecular methods and serum markers.” 2007. Doctoral Dissertation, Texas A&M University. Accessed February 27, 2021.
http://hdl.handle.net/1969.1/4696.
MLA Handbook (7th Edition):
Suchodolski, Jan S. “Assessment of the canine intestinal microflora using molecular methods and serum markers.” 2007. Web. 27 Feb 2021.
Vancouver:
Suchodolski JS. Assessment of the canine intestinal microflora using molecular methods and serum markers. [Internet] [Doctoral dissertation]. Texas A&M University; 2007. [cited 2021 Feb 27].
Available from: http://hdl.handle.net/1969.1/4696.
Council of Science Editors:
Suchodolski JS. Assessment of the canine intestinal microflora using molecular methods and serum markers. [Doctoral Dissertation]. Texas A&M University; 2007. Available from: http://hdl.handle.net/1969.1/4696
. 
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