Animal & Veterinary
FDA Commissioner Visits CVM’s Office of Research
FDA Veterinarian Newsletter September/October 2003 Volume XVIII, No 5
On September 5, 2005, FDA Commissioner, Dr. Mark McClellan visited CVM’s Office of Research in Laurel, Maryland for a firsthand view of CVM’s state-of-the-art facility. Dr. Linda Youngman, Director of the Office of Research (OR), provided a brief introduction of ongoing research efforts, and accompanied Dr. McClellan on the tour.
CVM scientists showed Dr. McClellan an adult steer prepared for a laparoscopic (minimally invasive) surgical approach, similar to so-called “keyhole surgery” in humans, to obtain a small biopsy sample of an internal organ under local anesthesia. The biopsy sample is used to develop an estimate of the drug residue level in edible animal tissue as part of the CVM food safety program. The laparoscopic surgery is performed by veterinarian Dr. Alberto Chiesa, visiting scientist from Spain, who has been trained in this minimally invasive approach to surgery at the University of California and the Ohio State University. He is assisted in the surgery by Dr. Richard Cullison, and Dr. Keesla Moulton, OR staff fellow from Mississippi State University and director of the current research effort to determine tissue-fluid correlations as related to drug residue concentration in meat animals.
Dr. McClellan was given a tour of CVM’s Office of Research state-of-the-art aquaculture facility by Dr. Renate Reimschuessel. The facility is approximately 5,000 sq ft. and has specialized facilities for conducting infectious studies, radioactive drug exposures and comprehensive fish surgeries. Species currently being studied include tilapia, rainbow trout, Atlantic salmon, channel catfish, and large mouth bass. In addition, goldfish are being used as models for ornamental species to study fish diseases and their treatments.
Research at the facility focuses on both regulatory priorities and the needs of the burgeoning aquaculture industry. The U.S. consumption of aquaculture-reared seafoods continues to grow as wild-caught stocks of fish continue to decrease – thus, the growing need for safe and effective therapies for aquaculture use is evident. CVM’s Office of Research’s studies include utilizing aquatic animal disease models to facilitate new animal drug efficacy trials and conducting residue depletion studies in multiple fish species to facilitate grouping of species (species grouping) on the basis of their metabolism of various drug classes. Dr. Shaikh is the study director for OR’s species grouping studies.
Dr. McClellan visited the Center for Devices and Radiological Health’s Office of Science and Technology (OST), Division of Life Sciences, Laboratory of Preclinical Studies. The Director of the Office, Dr. Larry Kessler, introduced Dr. Marilyn Lightfoote (Director, Division of Life Sciences) and Dr. Melvin Stratmeyer (Director, Health Sciences Branch) and briefly discussed the Office’s laboratory-based program and its role in supporting the Center’s regulatory work. Dr. Stephen Hilbert presented the regulatory and research components of the heart valve program. Dr. McClellan then proceeded to the OST interventional radiology/cardiology suite where an animal study was in progress. This study is part of a preclinical animal trial designed to address specific regulatory issues associated with emerging medical device technology. It was explained that one spedific aim of the current preclinical animal trial is to evaluate the effect of gender on stent versus angioplasty performance in a swine model of coronary atherosclerosis.
The study team was introduced (Dr. William Pritchard, Dr. John Karanian, Dr. Diane Wray-Cahen, Dr. Stephen Hilbert, Autumn Ashby and Dr. Abii Polycarp) as the Commissioner scrubbed-in to participate in the sterile procedure. Dr. McClellan was directed by Dr. Pritchard to perform a diagnostic angiogram of the swine coronaries and then proceeded to successfully deliver and deploy a coronary stent. The animal was subsequently recovered for future studies.
Following the tours, Dr. Youngman provided a talk for Commissioner McClellan highlighting a few of CVM’s ongoing research programs:
- Microbial Source Tracking (MST) Studies – used to identify methods by which to determine the animal source of the foodborne pathogens: Salmonella and Campylobacter.
- Standardization of Antimicrobial Susceptibility Testing Methods – necessary to allow comparability of data between testing laboratories, and to provide a means for quality control of testing components and procedures to ensure reliable and repeatable data.
- Development of Multiresidue Methods for Veterinary Drug Residues – OR scientists have long recognized the need for radical improvements in the time- and cost-effectiveness of measuring for veterinary drug residues in imported foods. Thus, they developed a two-phase extraction scheme that permits rapid extraction of both organic and aqueous phase drugs. They then developed, and are now optimizing, analytical methods that will permit resolution of 18 different drugs (of 6 different classes) in one analytical run. Use of these methods in ORA laboratories should result in dramatic improvements in the numbers of samples that can ultimately be analyzed.
- Antibiotic Resistance Patterns of Foodborne Bacterial Pathogens Isolated from Retail Meats – The project objectives are to gain a better understanding of the contribution our food supply contributes to the dissemination of antimicrobial resistant foodborne bacterial pathogens, especially Salmonella, Campylobacter, and E. coli in meat and poultry.
- Development and Validation of Methods to Help Enforce FDA’s Feed Ban – A validated PCR method to detect bovine material has been transferred to ORA. This method is easier to perform than feed microscopy, and the method will increase the number of samples that can be analyzed to help protect the U.S. from possible emergence of BSE.
Dr. McClellan asked if there were new, emerging issues for CVM that were relevant to OR’s research programs. Dr. Youngman replied that “the safety of food products from genetically-altered animals is a critical, emerging issue for CVM, and OR scientists are receiving training in this area.”