Current Projects
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Our Group Focuses on: |
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Outcomes Research and Epidemiology
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As primary faculty of the Center for Outcomes Research and Epidemiology (CORE website), I collaborate with companies by providing expertise in statistical analysis of observational and experimental research data, as well as teaching and training of veterinary and nutritional technical services professionals on principles for population data and other statistical and epidemiological concepts.
In collaboration with the Department of Agriculture, Arthropod-borne Animal Diseases Research Unit, we are working on a study that aims to define risk profiles that quantify the distribution of JEV risk in pig, bird, mosquito and human populations and to explore the impact of changes in risk factors or of implementing mitigation strategies in the risk of introduction of JEV in USA. Specific objectives include: 1) perform a systematic review and meta-analysis (SR-MA) to appraise available scientific literature on risk factors and mitigation strategies for JEV control, and 2) utilize a quantitative risk assessment tool to explore risk profiles, costs and feasibility of implementation of interventions and their impact on risk factors, as well as to identify data gaps to generate further research questions |
Effect of administration of direct-fed microbials on Salmonella lymph node harborage and E. coli O157 shedding in cattle |
Direct-fed microbials (DFM) are probiotics that act by excluding harmful bacteria like E. coli and preventing its colonization in the digestive tract. The objective of this study is to determine whether the administration of a high-dose of DFM (Lactobacillus acidophilus NP51 and Propionibacterium freudenreichii NP24) is associated with E. coli O157 shedding in feces of cattle in feedlot operations. Twenty commercial feedlots in Nebraska, 10 that administer DFM and 10 that do not, were sampled three times from June to September 2017. Twenty-two pen-floor fecal samples weree collected from three pens in each feedlot, per visit. Samples were subjected to cultural and molecular procedures for detection (immunomagnetic separation, plating on selective media, followed by PCR confirmation) and spiral plating for quantification. The results of this study showed that Bovamine Defend was effective at reducing E. coli fecal shedding in feedlot cattle, however this association differed by sampling visit. Therefore DFMs can be used as an effective control measure, especially during periods of high risk of transmission, to reduce the pathogen load of cattle entering the slaughter plant and subsequently reduce the burden of E. coli O157 illnesses in humans. Currently, we are evaluating the effect of the whole administration of a Saccharomyces cerevisiae fermentation product on the prevalence and concentration of Salmonella in lymph nodes of cull dairy cattle. |
Epidemiology of Shiga toxin-producing Escherichia coli in pre- and peri-harvest cattle |
Dr. Cernicchiaro in collaboration with Drs. David Renter, Michael Sanderson, T.G. Nagaraja and Rodney Moxley, among others, graduate students and interns have identified several data gaps in the literature pertaining to prevalence and concentration of non-O157 and O157 Shiga toxin-producing E. coli (STEC) in feces, hides and carcasses of commercial cattle using knowledge synthesis and translation methods (Systematic Reviews and Meta-analyses of published literature). In order to fill some of these data gaps we designed and implemented studies to determine the prevalence and concentration of STEC-7 in commercial feedlot cattle as well as we determined the applicability of culture- and PCR-based methods, used for isolation and identification of STEC in feces, on hide and carcass samples and validated these diagnostic tests for detection of STEC-7 using field samples. Furthermore, we have assessed seasonality and geographic region as potential drivers of STEC-7 fecal prevalence in commercial feedlot cattle in three studies conducted during summer 2013, winter and summer 2014. Moreover, we determined the prevalence and concentration of STEC-7 serogroups on hides-on samples and of indicator organisms on hides and carcass surface samples of commercial feedlot beef cattle in large commercial processing plants during summer 2015.
These studies were funded by USDA- STEC CAP grant. For more information about the STEC CAP grant, visit www.stecbeefsafety.org/ |
Investigation of association between antimicrobial use and emergence of antimicrobial resistance in indicator and pathogenic bacteria in feedlot cattle |
There is evidence that the use of antibiotics for treatment, prophylaxis, and growth promotion increases the prevalence of antimicrobial resistance (AMR) in food animals. Because people and animals share bacterial flora, AMR is a significant public health issue. This study focusses on understanding the effects of administration of antimicrobials on the possible emergence and spread of antimicrobial resistance in gut commensals (Enterococcus spp. and Escherichia coli) and foodborne pathogens (Salmonella spp. and Campylobacter spp.) shed in feces of beef cattle.
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Epidemiology of Bovine Respiratory Disease Complex in feedlot cattle |
We have applied a variety of analytic tools to quantify the effects of risks factors associated with BRDC health, production, and economics impacts. Currently, I collaborate on a BRDC grant led by Dr. David Renter that seeks to define unique health risk profiles that quantify the distribution of BRDC risks for defined subpopulations of at-risk feeder cattle by using risk analysis and economic models. We expect that our results will have immediate and sustainable impacts on the U.S. beef industry by improving BRDC health and economic risk management as well as disease control strategies.
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Invasive Mosquito Project |
I collaborate with Dr. Lee Cohnstaedt, Ashley Thackrah and Nolan Blankenau in the invasive mosquito project in the design and implementation of data collection tools. The Invasive Mosquito Project (IMP) was launched recently as an initiative that pairs high school teachers and students with mosquito control and public health professionals. This partnered citizen science classroom project helps high school teachers meet national education requirements (next generation science standards), and students learn about mosquitoes, public health, and safety. One of the main goals of the project is to transform teachers and students (non-professionals) into citizen scientists. The IMP provides educational materials in the form of lesson plans, PowerPoint® presentations, and protocols for teachers and students, which can be downloaded from the IMP website (www.citizenscience.us).
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Other Projects/Consulting |
I collaborate with several faculty in different departments within the College and the University, as well as with researchers in other Institutions on areas pertaining to study design and implementation, and statistical analyses of observational and experimental data.
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