Advanced search options

Advanced Search Options 🞨

Browse by author name (“Author name starts with…”).

Find ETDs with:

in
/  
in
/  
in
/  
in

Written in Published in Earliest date Latest date

Sorted by

Results per page:

Sorted by: relevance · author · university · dateNew search

You searched for +publisher:"Texas A&M University" +contributor:("Rodrigues, Aline"). Showing records 1 – 2 of 2 total matches.

Search Limiters

Last 2 Years | English Only

No search limiters apply to these results.

▼ Search Limiters


Texas A&M University

1. McKelvey, Jessica A. The Role of Antimicrobial Peptide Resistance Genes, virK and ybjX, during Salmonella enterica Serovar Enteritidis Infection in the Chicken Reproductive Tract.

Degree: MS, Biomedical Sciences, 2014, Texas A&M University

Salmonella enterica serovar Enteritidis (S. Enteritidis) is a major etiologic agent of non-typhoid salmonellosis, which causes 1.028 million cases with approximately 400 deaths in the United States. S. Enteritidis persistently and silently colonizes the intestinal and reproductive tract of laying hens, resulting in contaminated poultry products. The consumption of contaminated poultry products has been identified as a significant risk factor for human salmonellosis. To understand the mechanisms S. Enteritidis utilizes to colonize and persist in laying hens, we used selective capture of transcribed sequences to identify genes over-expressed in the chicken macrophage cell line (HD11) and in primary chicken oviduct epithelial cells. From the 15 genes found to be overexpressed in both cell types, we characterized the antimicrobial peptide resistance genes (AMPR), virK and ybjX, in vitro and in vivo. In vitro, AMPR genes were required for natural morphology, motility, secretion, defense against detergents such as EDTA and bile salts, and resistance to antimicrobial peptides polymyxin B and avian β-defensins. From this, we inferred the AMPR genes play a role in outer membrane stability and/or modulation. AMPR genes also played distinct roles in macrophage invasion and survival. In laying hens, both AMPR genes were involved in early intestinal colonization and fecal shedding. In the reproductive tract, virK was required in early colonization while a deletion of ybjX caused increased ovary colonization and egg deposition. In conclusion, data from the present study indicate that AMPR genes are differentially utilized in various host environments to defend against host immunity, with the possibility this is through mechanisms that modulate the outer membrane; this ultimately assists S. Enteritidis in persistent and silent hen colonization. Decoding the specific mechanisms employed by S. Enteritidis during colonization will aid in better control mechanisms to reduce this pathogen’s prevalence. Advisors/Committee Members: Zhang, Shuping (advisor), Berghman, Luc (committee member), Adams , Leslie G. (committee member), Lawhon, Sara (committee member), Rodrigues , Aline (committee member).

Subjects/Keywords: Salmonella enterica Serovar Enteritidis; Antimicrobial Peptide Resistance; Chicken Reproductive tract

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

McKelvey, J. A. (2014). The Role of Antimicrobial Peptide Resistance Genes, virK and ybjX, during Salmonella enterica Serovar Enteritidis Infection in the Chicken Reproductive Tract. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/153280

Chicago Manual of Style (16th Edition):

McKelvey, Jessica A. “The Role of Antimicrobial Peptide Resistance Genes, virK and ybjX, during Salmonella enterica Serovar Enteritidis Infection in the Chicken Reproductive Tract.” 2014. Masters Thesis, Texas A&M University. Accessed November 30, 2020. http://hdl.handle.net/1969.1/153280.

MLA Handbook (7th Edition):

McKelvey, Jessica A. “The Role of Antimicrobial Peptide Resistance Genes, virK and ybjX, during Salmonella enterica Serovar Enteritidis Infection in the Chicken Reproductive Tract.” 2014. Web. 30 Nov 2020.

Vancouver:

McKelvey JA. The Role of Antimicrobial Peptide Resistance Genes, virK and ybjX, during Salmonella enterica Serovar Enteritidis Infection in the Chicken Reproductive Tract. [Internet] [Masters thesis]. Texas A&M University; 2014. [cited 2020 Nov 30]. Available from: http://hdl.handle.net/1969.1/153280.

Council of Science Editors:

McKelvey JA. The Role of Antimicrobial Peptide Resistance Genes, virK and ybjX, during Salmonella enterica Serovar Enteritidis Infection in the Chicken Reproductive Tract. [Masters Thesis]. Texas A&M University; 2014. Available from: http://hdl.handle.net/1969.1/153280


Texas A&M University

2. Gold, Randi. Carriage of Virulence Factors and Antimicrobial Resistance Genes in Staphylococcus pseudintermedius from Dogs.

Degree: PhD, Veterinary Microbiology, 2015, Texas A&M University

Staphylococcus pseudintermedius is the most common microorganism isolated from canine pyoderma and opportunistic infections. Prevalence of methicillin-resistant S. pseudintermedius (MRSP) has increased and multi-drug resistance has become common. A total of 734 S. pseudintermedius isolates collected from dogs presented to the Veterinary Medical Teaching Hospital from 2007 to 2012 were studied. Isolates were analyzed for antimicrobial resistance and virulence gene carriage. With the emergence of methicillin resistance, veterinarians have begun to use antimicrobials such as amikacin, to treat life-threatening MRSP infections. The most widespread mechanism of amikacin resistance is drug inactivation by aminoglycoside modifying enzymes (AMEs). The most prevalent gene detected here was aph(3′)- IIIa found in 75% (24/32) of isolates followed by aac(6′)/aph(2′′) and ant(4′)-Ia in 12% (4/32) and 3% (1/32), respectively. There was a significant association between amikacin and methicillin resistance. Since AMEs can be transferred from one bacteria to another, amikacin resistance may represent a new nosocomial and zoonotic threat. Clindamycin is an alternative to β-lactam antimicrobial therapy for canine pyoderma. Inducible and constitutive resistance to clindamycin can occur. Approximately forty erm genes encoding methylases involved in clindamycin resistance have been reported, with ermB most commonly found among S. pseudintermedius. We found eight of 608 isolates tested, positive for inducible clindamycin resistance by D-test and PCR detection of ermB. A vaccine against staphylococcal pyoderma would reduce the reliance on antimicrobial drugs. Staphylococcal cell-wall associated proteins (CWAPs) involved in colonization of the host are attractive potential vaccine targets. Eighteen CWAPs encoded by sps genes have been described in S. pseudintermedius; however, four vary in occurrence. Isolates were analyzed by polymerase chain reaction (PCR) for the presence of mecA, SCCmec type I-VI, and spsF, spsO, spsP, and spsQ. There was a significant association between methicillin resistance and carriage of spsP and spsQ. spsP and spsQ may be viable vaccine targets. Advisors/Committee Members: Lawhon, Sara (advisor), Cohen, Noah (committee member), Rodrigues, Aline (committee member), Fajt, Virginia (committee member), Patterson, Adam (committee member).

Subjects/Keywords: staphylococcus pseudintermedius; pyoderma; methicillin-resistant; amikacin resistance; inducible clindamycin resistance

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Gold, R. (2015). Carriage of Virulence Factors and Antimicrobial Resistance Genes in Staphylococcus pseudintermedius from Dogs. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/155019

Chicago Manual of Style (16th Edition):

Gold, Randi. “Carriage of Virulence Factors and Antimicrobial Resistance Genes in Staphylococcus pseudintermedius from Dogs.” 2015. Doctoral Dissertation, Texas A&M University. Accessed November 30, 2020. http://hdl.handle.net/1969.1/155019.

MLA Handbook (7th Edition):

Gold, Randi. “Carriage of Virulence Factors and Antimicrobial Resistance Genes in Staphylococcus pseudintermedius from Dogs.” 2015. Web. 30 Nov 2020.

Vancouver:

Gold R. Carriage of Virulence Factors and Antimicrobial Resistance Genes in Staphylococcus pseudintermedius from Dogs. [Internet] [Doctoral dissertation]. Texas A&M University; 2015. [cited 2020 Nov 30]. Available from: http://hdl.handle.net/1969.1/155019.

Council of Science Editors:

Gold R. Carriage of Virulence Factors and Antimicrobial Resistance Genes in Staphylococcus pseudintermedius from Dogs. [Doctoral Dissertation]. Texas A&M University; 2015. Available from: http://hdl.handle.net/1969.1/155019

.