Department of Animal Science
B.S., 1991. Microbiology, Fudan University, P.R.China
M.S., 1994. Microbiology & Immunology, Fudan University, P.R.China
Ph.D., 1998. Animal Science, The Ohio State University
Postdoc 1999-2000. Bacterial Pathogenesis Pharmacology, Case Western
Postdoc 2000-2003. Animal Health/Food Safety, Veterinary Preventive Medicine, The Ohio State University
Response of intestinal microbiota to antibiotic growth promoter; Infectious diseases and food safety with emphasis on the molecular mechanisms of pathogenesis and antimicrobial resistance of zoonotic foodborne human pathogens.
Research in my laboratory focuses primarily on foodborne pathogens (e.g. Campylobacter jejuni) as well as normal intestinal microbiota important in feed digestion and nutrient assimilation. Long-term goal is to develop practical microbiota-based strategies to enhance growth and sustainability of food animals and to develop innovative intervention strategies and diagnostic tools to control infectious diseases in animal reservoirs, consequently improving both the quantity and the safety of our food supplies.
The research project relevant to UTORC mission is to determine theeffect of antibiotic growth promoter on intestinal microbiota using chicken model system.Antibiotic growth promoters (AGPs) have been used as feed additives to improve average daily weight gain and feed efficiency in food animals for more than five decades. However, use of AGPs is associated with the emergence of antibiotic-resistant human pathogens of animal origins and ending the use of AGPs is a worldwide trend to protect food safety and public health. Thus, effective alternatives to AGPs are urgently needed to maintain current animal production level without threatening public health. Understanding the mode of action of AGP is critical for developing such effective means. Although it is widely accepted that the growth promoting effect of AGPs is mediated through intestinal microbiota, little is known about microbial diversity and dynamics in the animal intestine in response to AGP treatment. We hypothesize that use of AGP change the diversity and structure of microbial communities in the animal intestine and ultimately results in an optimal and balanced microbiota for better growth performance of food animals. Using a well simulated chicken model system, we are investigating the effect of AGP on diversity and abundance of intestinal microbiota and identifying microorganisms that are potentially beneficial and detrimental to animal nutrition and productivity. Culture-independent assessment of microbiota diversity and dynamics will be accomplished by metagenomic, ribosomal RNA gene clone library, and quantitative real-time PCR analyses. It is anticipated that results of our research will provide basic information on the mode of action of AGPs and allow us to identify potential keystone microorganisms, which may ultimately lead to development of alternative microbiota-based strategies for promoting growth of food animals without use of AGPs.
Following are other major research projects focused on molecular mechanisms of bacterial pathogenesis and antibiotic resistance in Campylobacter jejuni, the leading bacterial cause of human enteritis in many industrialized countries:
- Develop CmeABC multidrug efflux pump-based intervention approaches to control Campylobacter infection. Funded by NIH.
- In vivo development, stability, and molecular mechanisms of macrolide resistance in Campylobacter jejuni. Funded by USDA.
Molecular basis and regulation of antimicrobial peptide resistance in Campylobacter jejuni.
Department of Animal Science
2505 River Drive
208B Brehm Animal Science
Knoxville, TN 37996-4574