A. Morrie Craig, PhD
Professor
e-mail:A.Morrie.Craig@oregonstate.edu
Sigma Xi
American Association of Veterinary Laboratory Diagnosticians (AAVLD)
International Society of Animal Clinical Biochemistry (ISACB)
American Society for Microbiology (ASM)
Society of Toxicology (SOT)
1996 OAS Scientist of the Year
PhD 1970 Oregon State University
Dr. Craig's primary research focus involves degradation of plant toxins that cause disease in livestock. Early in his career he discovered that pyrrolizidine alkaloids from tansy ragwort were degraded by sheep ruminal microbes. Based on the observation that sheep are less susceptible to tansy ragwort poisoning than cattle, it was proposed that the resistance of sheep is due to novel ruminal organisms or a population of organisms that can degrade pyrrolizidine alkaloids to non-toxic metabolites prior to systemic absorption by the host.
More recently, his laboratory has been studying endophytic fungi which infect several varieties of tall fescue and perennial ryegrass. These fungi confer benefits to the plant such as stress tolerance and pest resistance, while the plant provides energy and a sustainable environment for the fungus. Endophyte infection also results in the production of ergot alkaloids, however, which are responsible for a variety of insect and mammalian toxicoses. Preliminary results indicate that ruminal microbes have the capacity to degrade ergopeptine alkaloids in much the same way as pyrrolizidine alkaloids.
The plant alkaloids described above are nitroaromatic structures, which are also present in munitions (TNT, RDX and HMX). Recent studies have shown that ruminal microorganisms have the ability to degrade these energetic compounds. Ruminants are nutritionally rate-limited in nitrogen and amines and possess enzymes to assimilate nitrogen-containing compounds into amino acids. Therefore, a 'green solution' to munitions clean-up has been hypothesized: cool-season grasses will uptake TNT from contaminated soil and translocate it to plant tissue. The grass will then be ingested by sheep, where ruminal microbes will transform the nitroaromatic compound to non-toxic metabolites.
Lehner AF, Fannin N, Bush L, Craig AM, Tobin T. Fragmentation patterns of selected ergot alkaloids by electrospray tandem quadrupole mass spectrometry. Journal of Mass Spectrometry. In Press
Diernfeld ES, Atkinson S, Craig AM, Walker KC, Clauss M. Mineral concentrations in blood and liver tissue of captive and free-ranging rhinoceros species. Journal of Zoo and Wildlife Medicine. In Press
Lehner AF, Craig AM, Fannin N, Bush L, Tobin T. Ergot alkaloids screened by HPLC-electrospray[+] tandem quadrupole mass spectrometry.Journal of Mass Spectrometry. In Press
Duringer JM. Buhler DR, Craig AM. Comparison of hepatic in vitro metabolism of the pyrrolizidine alkaloid senecione in sheep and cattle. American Journal of Vererinary Research. In Press
Fisher MJ, Bohnert DW, Ackerman CJ, Schauer CS, DelCurto T, Craig AM, Vanzant ES, Harmon DL, Schrick FN. Evaluation of Perennial Ryegrass Straw as a Forage Source for Ruminants. Journal of Animal Science.In Press
Fleischmann TJ, Walker KC, Spain JC, Hughes JB, Craig AM. Anaerobic transformation of 2,4,6-TNT by bovine ruminal microbes. Biochemical and Biophysical Research Communications. 2004; 314(4):957-963.
Craig AM. Book Review:A Guide to Plant Poisoning of Animals in North America. Journal of the American Veterinary Medical Association. 2003; 223(10):800 and American Journal of Veterinary Research. 2003; 64(10):1204.
Aldrich-Markham S, Pirelli G, Craig AM. Endophyte Toxins in Grass Seed Fields and Straw Effects on Livestock. Extension Communication EM 8598. Oregon State University Extension Service. August 2003.
Hovermale JT, Craig AM. Metabolism of pyrrolizidine alkaloids by Peptostreptococcus Heliotrinreducens and a mixed culture derived from ovine ruminal fluid. Biophysical Chemistry. 2002; 101-102(12):387-399.
Lauridsen C, Engel H, Jensen SK, Craig AM, Taber MG. Lactating sows and suckling piglets preferentially incorporate RRR- over all-rac-alpha-tocopherol into milk, plasma and tissues. Journal of Nutrition. 2002; 132(6):1258-1264.
Lauridsen C, Engel H, Craig AM, Traber MG. Relative bioactivity of dietary RRR- and all-rac-alpha-tocopherol acetate in swine assessed using deuterium-labeled vitamin E. Journal of Animal Science. 2002; 80(3):702-707.
Kaneps A, Craig AM, Walker K, True J. Iontophoretic administration of dexamethasone into the tarsocrural joint in horses. American Journal of Veterinary Research. 2002; 63(1):11-14.
Hovermale JT, Craig AM. Correlation of ergovaline and lolitrem B levels in endophyte infected perennial ryegrass (lolium perenne). Journal of Veterinary Diagnostic Investigation. 2001; 13(4):323-327.
Tor-Agbidye J, Blythe LL, Craig AM. Correlation of endophyte toxins (ergovaline and lolitrem B) with clinical disease: Fescue Foot and Perennial Ryegrass Staggers. Veterinary and Human Toxicology. 2001; 43(3):140-146.
Schnitzius J, Hill ND, Thompson CS, Craig AM. Semi-quantitative determination of ergot alkaloids in seed, straw and digesta samples using a competitive ELISA assay. Journal of Veterinary Diagnostic Investigation. 2001; 13(3):230-237.
Piercy RJ, Hinchcliff KW, Morley PS, DiSilvestro RA, Reinhart GA, Nelson S, Schmidt KE, Craig AM. Vitamin E and exertional rhabdomyolysis during endurance sled dog racing. Journal of Neuromuscular Disorders. 2001; 11(3):278-286.
Johnston WH, Karchesy JJ, Constantine GH, Craig AM. Antimicrobial activity of some Pacific Northwest woods against anaerobic bacteria and yeast. Phytotherapy Research. 2001; 15(7):586-588.
Piercy RJ, Hinchcliff KW, Morley PS, DiSilvestro RA, Reinhart GA, Nelson S, Schmidt KE, Craig AM. Association between vitamin E and enhanced performance in sled dogs. Medicine and Science in Sports and Exercise. 2001; 33(5):826-833.
Books
Blythe LL, Gannon JR, Craig AM. Care of the Racing Greyhound: A Guide for Trainers, Breeders, and Veterinarians. American Greyhound Council, Abilene, KS, 1994.