+publisher:"Texas A&M University" +contributor:("Fajt, Virginia")

You searched for +publisher:"Texas A&M University" +contributor:("Fajt, Virginia"). Showing records 1 – 7 of 7 total matches.

▼ Search Limiters

Texas A&M University

1. Christian, Kristi Lynn. The relationship between the level of antibiotic use and resistance among enteric bacteria in a multi-site integrated human and swine population.

Degree: MS, Epidemiology, 2009, Texas A&M University

URL: http://hdl.handle.net/1969.1/ETD-TAMU-2738

► The objective of this longitudinal study was to study the relationship between changes in prevalence of resistant enteric bacteria associated with mean monthly doses (MMD)… (more)

▼ The objective of this longitudinal study was to study the relationship between changes in prevalence of resistant enteric bacteria associated with mean monthly doses (MMD) of various antibiotics used in each of two host species. From January 2004 – January 2007, monthly composite swine fecal samples and human wastewater samples representing various production and occupational cohorts, respectively, were collected from 19 geographically unique locations in east- and south-central Texas. Bacterial isolates cultivated on CHROMagar-E.coliTM and DifcoTM mEnterococcus (ME) were tested for susceptibility to multiple antibiotics by microbroth dilution using the SensititreTM system. The relationship between the prevalence of resistant bacteria, sampling period, and antibiotic use within each host species was assessed in a generalized linear model adjusted for the dependence of responses within location using a binomial distribution and logit link function in STATA® ver. 9.2. For the swine E. coli isolates, the relationship between tetracycline resistance and level of chlortetracycline (CTC) use in swine illustrated a dose-response relationship, with odds ratios (OR) of 1.20 and 1.81 (P < 0.05) for second- and third-level categories of MMD relative to baseline (zero-use) respectively. When considered by swine production groups, intake boar isolates had an elevated relative odds of resistance to tetracycline (OR = 1.51, P < 0.05), and the nursery units had an elevated odds (OR = 2.61, P < 0.05) of exhibiting resistance to ceftiofur, relative to pigs housed in the farrowing barns. Regarding swine Enterococci isolates, those swine from locations that utilized tylosin had an elevated OR of 3.54 (P < 0.05) of exhibiting resistance to tylosin, relative to those locations that used no tylosin. At this juncture, an apparent occupational risk of harboring tetracycline-resistant E. coli, and the apparent sparing effect (Enterococcus spp.) associated with exposure to swine production, remain unexplained. This study demonstrated that the prevalences of tetracycline- and tylosin-resistant enteric bacteria swine were dependent on CTC and tylosin use in feed, respectively. Swine production group-effects on the prevalence of tetracycline, ceftiofur, and erythromycin resistance were also important. This study provides a better understanding of the relationships between antibiotic prescribing practices at the ecologic level and the relative odds of carriage of resistant bacteria within two host species in a vertically integrated agri-food system. Advisors/Committee Members: Scott, H. Morgan (advisor), Fajt, Virginia (committee member), Harvey, Roger B. (committee member), Lawhorn, Bruce (committee member).

Subjects/Keywords: antibiotic; resistance; swine; human; integrated system; multi-site

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Christian, K. L. (2009). The relationship between the level of antibiotic use and resistance among enteric bacteria in a multi-site integrated human and swine population. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2738

Chicago Manual of Style (16^th Edition):

Christian, Kristi Lynn. “The relationship between the level of antibiotic use and resistance among enteric bacteria in a multi-site integrated human and swine population.” 2009. Masters Thesis, Texas A&M University. Accessed January 22, 2021. http://hdl.handle.net/1969.1/ETD-TAMU-2738.

MLA Handbook (7^th Edition):

Christian, Kristi Lynn. “The relationship between the level of antibiotic use and resistance among enteric bacteria in a multi-site integrated human and swine population.” 2009. Web. 22 Jan 2021.

Vancouver:

Christian KL. The relationship between the level of antibiotic use and resistance among enteric bacteria in a multi-site integrated human and swine population. [Internet] [Masters thesis]. Texas A&M University; 2009. [cited 2021 Jan 22]. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2738.

Council of Science Editors:

Christian KL. The relationship between the level of antibiotic use and resistance among enteric bacteria in a multi-site integrated human and swine population. [Masters Thesis]. Texas A&M University; 2009. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2738

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

URL: http://hdl.handle.net/1969.1/155019

► 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… (more)

▼ 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 Details Similar Records Cite « Share

❌

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

APA (6^th 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 (16^th Edition):

Gold, Randi. “Carriage of Virulence Factors and Antimicrobial Resistance Genes in Staphylococcus pseudintermedius from Dogs.” 2015. Doctoral Dissertation, Texas A&M University. Accessed January 22, 2021. http://hdl.handle.net/1969.1/155019.

MLA Handbook (7^th Edition):

Gold, Randi. “Carriage of Virulence Factors and Antimicrobial Resistance Genes in Staphylococcus pseudintermedius from Dogs.” 2015. Web. 22 Jan 2021.

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 2021 Jan 22]. 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

Texas A&M University

3. Hairgrove, Thomas Bearl. Emerging and Reemerging Diseases of Texas Beef Cattle.

Degree: PhD, Animal Science, 2016, Texas A&M University

URL: http://hdl.handle.net/1969.1/187368

► This dissertation focused on three emerging/reemerging diseases posing economic impacts on Texas livestock producers. Bovine trichomoniasis is a regulated disease requiring diagnostic testing; however, current… (more)

▼ This dissertation focused on three emerging/reemerging diseases posing economic impacts on Texas livestock producers. Bovine trichomoniasis is a regulated disease requiring diagnostic testing; however, current diagnostic protocols are problematic. Major obstacles resulting from variable collection procedures and discrepancies in sample handling and laboratory test accuracy need further investigation. Epizootic hemorrhagic disease primarily affects white-tailed deer; however, it is unclear why clinical disease is rarely exhibited in cattle in the same region, requiring the investigation of seroprevalence in Texas cattle. Bovine viral diarrhea (BVD) causes significant reproductive loss and complicates other diseases through immunosuppression. Although vaccination is the primary method of mitigating fetal infection, a systematic review assessing fetal protection from vaccination is needed. Methods to examine the collection, shipment, and diagnostics associated with bovine trichomoniasis included (1) testing of infected bulls for sample quality and testing accuracy related to time, collectors, and individual bulls; (2) evaluation of samples with temperature sensors in a controlled environment when shipped by common carrier; and (3) evaluation of a patented polymerase chain reaction (PCR) technique for expedient sample handling and improved diagnostic sensitivity. Methods to evaluate prevalence of epizootic hemorrhagic disease in Texas cattle were based on random blood sera collections from 11 auction markets. Methods to assess safety and efficacy of BVD vaccines for fetal protection were based on a systematic review of the scientific literature. There was little variation in bovine trichomoniasis test results due to collector or bull, indicating proper and standardized sample collection protocol increased test accuracy. Shipping samples in temperature-controlled containers to arrive at the laboratory within 24 hours also improved diagnostic accuracy. The newly patented PCR test exhibited 100% diagnostic sensitivity and 99% specificity for field samples from 56 positive and 110 negative bulls for improved test accuracy. A high seroprevalence of epizootic hemorrhagic disease (70% to 97% depending on different threshold titer positive cutoff values) was seen in Texas auction cattle, but clinical disease is rare. Much of the scientific literature dealing with BVD supports vaccination for fetal protection but lacks transparency regarding experimental design, creating a potential for bias and making evaluation of these studies difficult. Advisors/Committee Members: Friend, Ted (advisor), Herring, Andy (committee member), Sawyer, Jason (committee member), Fajt, Virginia (committee member).

Subjects/Keywords: Emerging Diseases

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Hairgrove, T. B. (2016). Emerging and Reemerging Diseases of Texas Beef Cattle. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/187368

Chicago Manual of Style (16^th Edition):

Hairgrove, Thomas Bearl. “Emerging and Reemerging Diseases of Texas Beef Cattle.” 2016. Doctoral Dissertation, Texas A&M University. Accessed January 22, 2021. http://hdl.handle.net/1969.1/187368.

MLA Handbook (7^th Edition):

Hairgrove, Thomas Bearl. “Emerging and Reemerging Diseases of Texas Beef Cattle.” 2016. Web. 22 Jan 2021.

Vancouver:

Hairgrove TB. Emerging and Reemerging Diseases of Texas Beef Cattle. [Internet] [Doctoral dissertation]. Texas A&M University; 2016. [cited 2021 Jan 22]. Available from: http://hdl.handle.net/1969.1/187368.

Council of Science Editors:

Hairgrove TB. Emerging and Reemerging Diseases of Texas Beef Cattle. [Doctoral Dissertation]. Texas A&M University; 2016. Available from: http://hdl.handle.net/1969.1/187368

4. Mays, Travis Parker. Establishing Decision Limits for Therapeutic Drugs Detected in Animals Exhibited at Livestock Shows.

Degree: PhD, Biomedical Sciences, 2019, Texas A&M University

URL: http://hdl.handle.net/1969.1/186156

► Food animal species, such as cattle, sheep, goats, and pigs, are widely exhibited at stock shows and fairs across the United States. Animals are judged… (more)

▼ Food animal species, such as cattle, sheep, goats, and pigs, are widely exhibited at stock shows and fairs across the United States. Animals are judged on phenotypical traits such as muscling, structural correctness, and frame-size. The level of competition is high, increasing the potential for illegal or unethical acts to gain a competitive advantage, such as doping. Antidoping regulation in the livestock show industry often involves drug testing. Detection of therapeutic drugs at very low concentrations in approved animal species raises questions about current anti-doping regulations in exhibition animals. Therefore, the purpose of this research was to identify and address data gaps in the current understanding of drug testing and drug disposition, and to integrate those data with published data to propose an approach to standardizing anti-doping policies, particularly those related to therapeutic drug use. To determine which drugs are most commonly identified in drug testing at livestock shows, a review of historical drug test results from a laboratory in Texas from 1999 to 2017 was performed. A total of 32,027 samples were tested during this period, of which 1,674 (5.2%) tested positive. Positive samples included a total of 42 different drugs and metabolites. Flunixin was the second most commonly identified drug. Currently no nonsteroidal anti-inflammatory drugs (NSAIDs) are approved by the Food and Drug Administration (FDA) for small ruminants, but drugs such as flunixin and meloxicam are used in small ruminants. Additionally, urine is the sample of choice when drug testing exhibition animals but there is a gap in the scientific literature describing drug concentrations in urine of small ruminants. Therefore, pharmacokinetic studies were performed describing plasma and urine concentrations of flunixin meglumine and meloxicam in goats. Drug levels in urine reached peak concentrations between 8 and 12 hours after dosing for both drugs. Urine concentrations for both flunixin and meloxicam fell below the limit of detection (LOD) of 0.5 ng/mL and 1 ng/mL, respectively, by 240 hours. Last, observed and published data, PK/PD modeling results, and measurement uncertainty were integrated to propose a method for establishing decision limits for therapeutic drugs detected in urine from animals exhibited at livestock shows. Advisors/Committee Members: Fajt, Virginia (advisor), Cohen, Noah (committee member), Stewart, Randolph (committee member), Jones, Meredyth (committee member).

Subjects/Keywords: Drug; Pharmacology; Analytical Chemistry; Doping; Livestock; Exhibition

1 more image…

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Mays, T. P. (2019). Establishing Decision Limits for Therapeutic Drugs Detected in Animals Exhibited at Livestock Shows. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/186156

Chicago Manual of Style (16^th Edition):

Mays, Travis Parker. “Establishing Decision Limits for Therapeutic Drugs Detected in Animals Exhibited at Livestock Shows.” 2019. Doctoral Dissertation, Texas A&M University. Accessed January 22, 2021. http://hdl.handle.net/1969.1/186156.

MLA Handbook (7^th Edition):

Mays, Travis Parker. “Establishing Decision Limits for Therapeutic Drugs Detected in Animals Exhibited at Livestock Shows.” 2019. Web. 22 Jan 2021.

Vancouver:

Mays TP. Establishing Decision Limits for Therapeutic Drugs Detected in Animals Exhibited at Livestock Shows. [Internet] [Doctoral dissertation]. Texas A&M University; 2019. [cited 2021 Jan 22]. Available from: http://hdl.handle.net/1969.1/186156.

Council of Science Editors:

Mays TP. Establishing Decision Limits for Therapeutic Drugs Detected in Animals Exhibited at Livestock Shows. [Doctoral Dissertation]. Texas A&M University; 2019. Available from: http://hdl.handle.net/1969.1/186156

Texas A&M University

5. Nunez, Chase Michael. The Use of Drugs in Captive White-Tailed Deer (Odocoileus virginianus): An Evaluation of Two Common Extra-Label Drug Uses in the Deer Breeding Industry.

Degree: MS, Biomedical Sciences, 2019, Texas A&M University

URL: http://hdl.handle.net/1969.1/188786

► The white-tailed deer (WTD) breeding and hunting industry is a large and growing industry with an economic impact of over a billion dollars in Texas… (more)

▼ The white-tailed deer (WTD) breeding and hunting industry is a large and growing industry with an economic impact of over a billion dollars in Texas alone. The increasing number of deer in captive breeding facilities results in increased veterinary drug use on deer. However, drugs can act differently even among similar species so further information on drug use in deer would help managers and veterinarians make more sound decisions when using drugs in deer. Two examples of novel extra-label drug use in WTD are studied, evaluated, and explained. Tulathromycin is a macrolide antibiotic used commonly to treat livestock, including deer, with bacterial respiratory infections, often delivered subcutaneous (SQ) or intramuscular (IM). Since it is logistically difficult to put hands on a WTD, even in most captive breeding situations, a study was conducted to evaluated tulathromycin as a candidate for remote-delivery dart (RDD) in WTD. Twelve WTD were darted with CO2 powered RDD projectors to administer 2.5 mg/kg of tulathromycin IM. Blood was then collected nine times over 30 days and the serum concentration for each sample was quantified in order to determine the pharmacokinetics of tulathromycin in each deer. Overall tulathromycin was poorly absorbed, reached low mean peak concentrations, had a high bioavailability, and an extremely long elimination half-life. The results indicated that darting with tulathromycin is an unpredictable means of administration and may not reach therapeutic concentrations. Flunixin meglumine (FM), a non-steroidal anti-inflammatory drug (NSAID), was also evaluated for extra-label use in WTD in a case study with 72 WTD in South Texas. Texas Parks and Wildlife has seen anecdotal evidence of FM effectively reducing the body temperature of hyperthermic animals during game captures. Three of the deer in the case study became severely hyperthermic and the FM was tested in conjunction with cold water enemas. With over half of the 72 deer being hyperthermic, and three severely hyperthermic, a 100% post 30-day survival is strong evidence of the effect of FM. Advisors/Committee Members: Cook, Walter E (advisor), Fajt, Virginia (committee member), Blue-McLendon, Alice (committee member).

Subjects/Keywords: White-tailed deer; Odocoileus virginianus; captive deer breeding; tulathromycin; Draxxin; flunixin meglumine; Banamine; darting

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Nunez, C. M. (2019). The Use of Drugs in Captive White-Tailed Deer (Odocoileus virginianus): An Evaluation of Two Common Extra-Label Drug Uses in the Deer Breeding Industry. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/188786

Chicago Manual of Style (16^th Edition):

Nunez, Chase Michael. “The Use of Drugs in Captive White-Tailed Deer (Odocoileus virginianus): An Evaluation of Two Common Extra-Label Drug Uses in the Deer Breeding Industry.” 2019. Masters Thesis, Texas A&M University. Accessed January 22, 2021. http://hdl.handle.net/1969.1/188786.

MLA Handbook (7^th Edition):

Vancouver:

Nunez CM. The Use of Drugs in Captive White-Tailed Deer (Odocoileus virginianus): An Evaluation of Two Common Extra-Label Drug Uses in the Deer Breeding Industry. [Internet] [Masters thesis]. Texas A&M University; 2019. [cited 2021 Jan 22]. Available from: http://hdl.handle.net/1969.1/188786.

Council of Science Editors:

Nunez CM. The Use of Drugs in Captive White-Tailed Deer (Odocoileus virginianus): An Evaluation of Two Common Extra-Label Drug Uses in the Deer Breeding Industry. [Masters Thesis]. Texas A&M University; 2019. Available from: http://hdl.handle.net/1969.1/188786

Texas A&M University

6. Padgett, Ashley Loren. Comparison of Transdermal Fentanyl and Intramuscularly Administered Buprenorphine for Postoperative Pain in Pregnant Sheep.

Degree: MS, Biomedical Sciences, 2018, Texas A&M University

URL: http://hdl.handle.net/1969.1/174041

► Designing perioperative analgesic regimen for ruminants is problematic as pain assessment is difficult and pregnancy adds additional considerations. The aim of this study was to… (more)

▼ Designing perioperative analgesic regimen for ruminants is problematic as pain assessment is difficult and pregnancy adds additional considerations. The aim of this study was to assess the nociceptive properties of intramuscularly administered buprenorphine and transdermally administered fentanyl utilizing a composite pain score system. To better confirm that the observed abnormal behavior was related to pain, the current study attempted to characterize the nociceptive properties of the analgesic agents at a given plasma drug concentration, which has not previously been done. Additionally, the study characterized transplacental movement of analgesic agents via fetal plasma drug concentrations. In this study, we compared intramuscularly administered buprenorphine at a dose of 0.01 mg/kg every 8 hours for 48 hours starting at induction for surgery (n=6) to transdermal fentanyl patches (n=6) applied in the dorsal thorax region 24 hours before surgery at a dose of 2μg/kg/hr for postoperative pain. Ewe blood samples were collected and signs of pain and sedation were measured 24 hours before surgery (time -24), induction to surgery (time 0), and 2, 4, 6, 8, 12, 24, 36, 48 hours after. Using an indwelling fetal arterial catheter that was placed during the surgery, fetal blood pressure was recorded and blood samples were collected. Drug concentrations were measured in maternal and fetal plasma and amniotic fluid. The buprenorphine treated ewes exhibited more pain consistent behaviors than those treated with fentanyl, and their postoperative pain scores were significantly higher than the preoperative value. There were also significant differences in cardiovascular variables from the anesthesia records between the two groups. Overall, transdermal administration of fentanyl provided adequate analgesia with little adverse effects, making it a candidate for optimal postoperative pain management in sheep. Advisors/Committee Members: Washburn, Shannon E (advisor), Lepiz, Mauricio L (committee member), Fajt, Virginia R (committee member), Patterson, Carly (committee member).

Subjects/Keywords: transdermal fentanyl; opioids; pregnant sheep; buprenorphine; analgesia; anesthesia

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Padgett, A. L. (2018). Comparison of Transdermal Fentanyl and Intramuscularly Administered Buprenorphine for Postoperative Pain in Pregnant Sheep. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/174041

Chicago Manual of Style (16^th Edition):

Padgett, Ashley Loren. “Comparison of Transdermal Fentanyl and Intramuscularly Administered Buprenorphine for Postoperative Pain in Pregnant Sheep.” 2018. Masters Thesis, Texas A&M University. Accessed January 22, 2021. http://hdl.handle.net/1969.1/174041.

MLA Handbook (7^th Edition):

Padgett, Ashley Loren. “Comparison of Transdermal Fentanyl and Intramuscularly Administered Buprenorphine for Postoperative Pain in Pregnant Sheep.” 2018. Web. 22 Jan 2021.

Vancouver:

Padgett AL. Comparison of Transdermal Fentanyl and Intramuscularly Administered Buprenorphine for Postoperative Pain in Pregnant Sheep. [Internet] [Masters thesis]. Texas A&M University; 2018. [cited 2021 Jan 22]. Available from: http://hdl.handle.net/1969.1/174041.

Council of Science Editors:

Padgett AL. Comparison of Transdermal Fentanyl and Intramuscularly Administered Buprenorphine for Postoperative Pain in Pregnant Sheep. [Masters Thesis]. Texas A&M University; 2018. Available from: http://hdl.handle.net/1969.1/174041

7. Rollo, Susan Noble. Herd-level Risk Factors Associated with Antimicrobial Susceptibility Patterns and Distributions in Fecal Bacteria of Porcine Origin.

Degree: PhD, Biomedical Sciences, 2012, Texas A&M University

URL: http://hdl.handle.net/1969.1/ETD-TAMU-2011-08-9755

► The purpose of this dissertation is threefold: to determine the differences in apparent prevalence and the antimicrobial susceptibility of Campylobacter spp. between antimicrobial-free and conventional… (more)

▼ The purpose of this dissertation is threefold: to determine the differences in apparent prevalence and the antimicrobial susceptibility of Campylobacter spp. between antimicrobial-free and conventional swine farms; secondly, to introduce an appropriate statistical model to compare the minimum inhibitory concentration distributions of Escherichia coli and Campylobacter spp. isolated from both farm types; and thirdly, to examine the potential herd level risk factors that may be associated with antimicrobial resistance of Campylobacter spp. and E. coli isolates from finishers on antimicrobial-free and conventional farming systems. In addition, a critical review of studies that have compared the levels and patterns of antimicrobial resistance among animals from antimicrobial-free and conventional farming practices was performed. Fecal samples from 15 pigs were collected from each of 35 antimicrobial-free and 60 conventional farms in the Midwestern U.S. Campylobacter spp. was isolated from 464 of 1,422 fecal samples, and each isolate was tested for susceptibility to 6 antimicrobials. The apparent prevalence of Campylobacter spp. isolates was approximately 33 percent on both conventional and antimicrobial-free farms. The proportion of antimicrobial resistance among Campylobacter was higher for three antimicrobials within conventional compared to antimicrobial-free farms. The susceptibilities of populations of bacteria to antimicrobial drugs were summarized as minimum inhibitory concentration (MIC) frequency distributions. The use of MIC values removed the subjectivity associated with the choice of breakpoints which define an isolate as susceptible or resistant. A discrete-time survival analysis model was introduced as the recommended statistical model when MICs are the outcome. A questionnaire was completed by each farm manager on biosecurity, preventive medication, vaccines, disease history, and production management. Multivariable population-averaged statistical models were used to determine the relationships among antimicrobial susceptibility patterns and potential herd-level risk factors. Controlling for herd type (antimicrobial-free versus conventional), each antimicrobial-bacterial species combination yielded unique combinations of risk factors; however, housing type, history of rhinitis, farm ventilation, and history of swine flu were significant in more than one model. A variety of herd-level practices were associated with the prevalence of antimicrobial resistance on swine farms. Further studies are encouraged when considering interventions for antimicrobial resistance on both antimicrobial-free and conventional farms. Advisors/Committee Members: Norby, Bo (advisor), Scott, H M. (committee member), Fajt, Virginia R. (committee member), Huber, John C. (committee member), Libal, Melissa (committee member).

Subjects/Keywords: antimicrobial resistance; minimum inhibitory concentration; discrete time survival analysis; antimicrobial-free farms; Escherichia coli; Campylobacter; risk factors; swine

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Rollo, S. N. (2012). Herd-level Risk Factors Associated with Antimicrobial Susceptibility Patterns and Distributions in Fecal Bacteria of Porcine Origin. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2011-08-9755

Chicago Manual of Style (16^th Edition):

Rollo, Susan Noble. “Herd-level Risk Factors Associated with Antimicrobial Susceptibility Patterns and Distributions in Fecal Bacteria of Porcine Origin.” 2012. Doctoral Dissertation, Texas A&M University. Accessed January 22, 2021. http://hdl.handle.net/1969.1/ETD-TAMU-2011-08-9755.

MLA Handbook (7^th Edition):

Rollo, Susan Noble. “Herd-level Risk Factors Associated with Antimicrobial Susceptibility Patterns and Distributions in Fecal Bacteria of Porcine Origin.” 2012. Web. 22 Jan 2021.

Vancouver:

Rollo SN. Herd-level Risk Factors Associated with Antimicrobial Susceptibility Patterns and Distributions in Fecal Bacteria of Porcine Origin. [Internet] [Doctoral dissertation]. Texas A&M University; 2012. [cited 2021 Jan 22]. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2011-08-9755.

Council of Science Editors:

Rollo SN. Herd-level Risk Factors Associated with Antimicrobial Susceptibility Patterns and Distributions in Fecal Bacteria of Porcine Origin. [Doctoral Dissertation]. Texas A&M University; 2012. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2011-08-9755

		in
And / Or
		in
And / Or
		in
And / Or
		in

Open Access Theses and Dissertations