Brief Summary of Minutes of Annual Meeting

Dr. Mark Kuhlenschmidt called the meeting to order at 8:50 am and new members and guests were introduced. Dr. Kuhlenschmidt then introduced Dr. Bert Stromberg as the new Administrative Advisor for NC1007. Dr. Stromberg presented his opening remarks, stressing that the North Central Regional Association emphasizes collaboration among members. This needs to be demonstrated by multi-institutional publications. Dr. Mary Torrence presented the CREES report. She provided a recent CSREES Budget summary and announced currently available RFAs and deadlines for proposal submissions. She informed the group about new initiatives and new directives in NRI for this next year. There is a need to develop a consortium of top researchers to address these new initiatives and intervention and management strategies will be important issues as they will have more impact. She recommended that the NC1007 group organize a large, multi-state proposal. Dr. Stromberg suggested a food safety multi-state project, using the recent PRRS proposal that has an internal grant review process as an example. This would give the group the flexibility needed to move in different directions. He reminded the group that CSREES wants a minimum number of proposals with maximum expertise represented. From 9:15 am on participants from the various experiment stations presented and discussed progress reports and principle accomplishments concerning their work on the NC-1007 project. In addition to the agenda were presentations by Dr. Besser on the epidemiology of antibiotic resistance and by Dr. Rahdy on establishment of a primary bovine fetal intestinal epithelial cell culture. At 4:10 pm, after the presentation of progress reports, Dr. Torrence, CSREES representative, commented on the large pool of expertise and wide range of species of organisms represented by NC1007. She suggested potential collaborative proposals for submission for NRI or NIH funding. Also, she would like to see less time and energy focused on presentation of research and more discussion of collaborative projects. Ideas were presented and discussed for large collaborative research proposals, including a national clinical trial of E. coli intervention strategies, the affects of elimination of growth promotors on animal health and food safety, the interplay of viral plus bacterial pathogens in the intestine of animals on food safety and zoonosis/how pathogens cross species barriers. Dr. Torrence is willing to work with the NC1007 group to identify alternative sources of funding and/or matching funds. She suggested that the group put together a pre-proposal which she would present to funding agencies to assess the level of interest in the ideas presented. The meeting was adjourned at 5:00 pm. The breakfast business meeting began at 8:05 am, November 9, 2003. We discussed the need for a new chair and co-chair for the CRWAD Enteric Disease Section and a keynote speaker for 2004. Dr. Stromberg volunteered to set up a ListServe for communication among NC1007 members. The business meeting was officially called to order at 8:45 am by Dr. Kuhlenschmidt in the meeting room. Announcements were made. Two Enteric Disease session chairs will be needed next year. An Animal Health Symposium grant will be used to pay honoraria to keynote speakers. Dr. Joens provided an update on CRWAD Committee business. Dr. Saif announced that NRI is soliciting topics from NC groups and suggested we submit topics. We decided that excess dues would be deposited to a SDSU account for use for the Graduate Student Awards, that we needed to disseminate our NC1007 information in an outreach fashion, and that we needed to find a web administrator to set up and maintain a NC1007 web site. Further discussion was directed towards outreach possibilities and the topic of a Symposium on Food Safety and/or Zoonotic diseases in general was reintroduced. There was no further business and the business meeting was adjourned. At 9:30 am new officers were elected. Both Drs. Maes and Besser were nominated to serve as Secretary. Dr. Besser declined nomination due to time constraints; Dr. Maes was unanimously voted new secretary. Instead of individual state collaboration discussions, the group as a whole discussed some avenues for creative new collaboration at 9:45 am. We discussed the outreach objective from the grant and decided to investigate setting up an informative web page and/or a meeting targeted toward producers or veterinary groups, which would include enterics, food safety and maybe even bioterrorism topics. More novel means of cooperative research that may result in collaborative grants were then discussed. Topics were discussed that would merge the groups expertise in and diversity of research. After discussion, group settled on the following general objectives: 1) What happens to the prevalence of zoonotic organisms in the presence/absence of growth promoters in animals? 2) What happens to the prevalence of animal pathogens in production animals grown in the presence and absence of growth promoters? 3) What happens to antimicrobial resistance profiles in zoonotic and animal pathogens in animals grown in the presence and absence of growth promoters? 4) What happens to therapeutic effect and disease rates with/without growth promoters, antibiotics, and on induced and native immunity? Dr. Torrence will approach funding agencies with the listed objectives and if there is a positive response from the funding agencies, NC1007 members will reconvene early 2004 to have further discussions and add specifics to the proposal. Drs. Isaacson and Besser volunteered to co-chair the organization of this interdisciplinary project. Dr. Saif announced that all station reports will need to be on CDs for preparation for the next project rewrite. The meeting was adjourned at approximately 12:00pm.

Objective 1: Define mechanisms of pathogen-host-environmental interactions in enteric and food borne diseases Brachyspira NE investigated a laboratory mouse model of B. pilosicoli-host interaction. An NADH oxidase gene (nox) PCR-based RFLP method has been developed for rapid identification of pathogenic and commensal Brachyspira present in a wide range of hosts. Three penicillin-binding proteins (PBPs) homologous to the PBPs 1, 3 and 5/6 of Escherichia coli have been identified in the membrane of B. pilosicoli. Campyobacter AZ assessed the pathogenicity of Camplobacter jejuni in broiler chickens. Broiler cecal samples were collected from processed biruds n processing plants located in Kansas, Iowa, and Washington. To date 315 samples have been collected and processed and 120 positive samples have been isolated. Az also assessed the presence and potential virulence of C. jejuni isolated from food and companion animals. Bovine, canine, feline, and avian feces or intestinal swabs from carcasses were cultured for C. jejuni and identity confirmed using broth enrichment and selective plating and PCR. A total of 437 fecal swabs were evaluated and 13,8% of dogs, 5% of goats, 94.7% of cattle, and 1.7% of avian species were positive for C. jejuni. All positive isolates were found be of comparable pathogenicity to C. jejuni M129, a human clinical strain. None of the isolates were resistant to either erythromycin or gentamicin and only 2% were resistant to ciprofloxacin although 25.5% were resistant to tetracycline. Az reported the isolation of potentially novel virulence genes from C. jejuni by cell sorting of a GFP promoter library. Coronavirus KS has isolated coronavirus from a horse with diarrhea. The virus hemagglutinates mouse erythrocytes and cross reacts with bovine coronavirus in ELISA assays. Cryptosporidium IL has isolated and partially characterized the intestinal lipid component that inhibits sporozoite binding to host cells and is currently identifying sporozoite genes transcribed in response to exposure to this lipid and binding to host cell membrane vesicles. Escherichia coli NE demonstrated EAST1 expression by a porcine strain of enterotoxigenic E. coli (ETEC). Genes for EAST1, LT and STb were located on large plasmids; genes for the latter two enterotoxins occurred on the same plasmid, whereas those for EAST1 occurred on a separate plasmid. Specific anti-capsular antibodies mediated bactericidal activity of porcine serum against a serum resistant ETEC strain, and killing activity occurred via the alternative complement pathway. Vaccination alone or in combination with direct-fed microbial product significantly reduced the prevalence of E. coli O157:H7 in feedlot cattle in clinical trials. SD demonstrated that E. coli expressing K88 fimbriae targeting glycoprotein receptors display greater virulence than those strains with K88 fimbriae targeting glycolipid receptors. Fimbriae alone cannot account for successful colonization of piglet intestines by E. coli and virulence of O157:H7 E. coli strains is highly correlated with the amount of Shiga toxin 2 produced by the strain in vitro. Lawsonia intracellularis MN has followed the progression of gross and histologic lesions associated with Lawsonia intracellularis(LI) infection in pigs and has evaluated the production of mucosal secretory IgA specific against the bacteria. MN has completed sequencing and annotation of the genome of LI. Overall the LI genome is 1,719,350 bp in size with one chromosome and three plasmids encoding a total of 1,346 ORFs. Sequencing and annotation also revealed, among others, a very large (26 kb) unique protein composed almost entirely of a-helices, located on the large plasmid and comprises ~2% of the entire genome. The analyses also identified numerous genes involved in pathogenicity and toxin production, including a largely intact Type III secretion system and numerous flagellar genes. Newly Recognized Enteric Viruses and Caliciviruses MI determined that bovine noroviruses and toroviruses were very prevalent in diarrheic samples collected from Michigan and Wisconsin dairy farms. OH previously determined the effective factor in intestinal contents preparation (ICP) required for porcine enteric calicivirus (PEC) growth in cell culture is a protein (or peptide) of < 50 kDa and that replication of PEC may depend on a cAMP signaling pathway suggesting a novel pathway for replication of an intestinal virus. Capped RNA transcripts derived from a full-length cDNA of the tissue culture adapted (TC) Cowden PEC were infectious when transfected into LLC-PK cells but only in the presence of IC. The infectious clone had 4 amino acid point mutations throughout its genome compared to the parent TC-PEC. Futhermore, the infection of gnotobiotic pigs with TC or wild type PEC induced similar serum neutralizing and serum or intestinal IgM, IgA and IgG antibody responses and protection against diarrhea. Rotavirus IL has synthesized a neoglycolipid receptor mimetic and demonstrated its ability to protect newborn pigs from rotavirus disease when orally inoculated at the time of virus challenge. Il has also discovered a new asialoganglioside binding activity in the inner rotavirus capsid that may mediate binding to synthetic asialoneoglycolipid mimetics and inhibition of in vitro infectivity of sialic-acid independent rotaviruses. NE has determined that of five cross-reactive linear B-cell epitopes located within VP5* of bovine group A rotavirus, three had cross-neutralizing activity between bovine rotaviruses with P7[5] and P6[1] serotype [genotype]. Salmonella MN has studied the frequency of phase variation among different strains. Highly virulent isolates SL1344 and I4028 were able to phase vary from on to off at the same frequency. Phase variation from off to on, however, was 100-fold more frequent in the highly virulent strains SL1344 and I4028 as compared to strain 798. Thus, while 798 can be stably maintained in both phenotypic phases, SL1344 and I4028 tend to stay in the virulent on phase. Also, the degree of invasiveness is higher in 798 cells in the on phase compared to the off phase. Strain 798 in the on phase were more invasive than either SL1344 or I4028 and mutations in hilA knocked out invasiveness in all three strains. Transmissible Gastroenteritis Virus and Porcine Respiratory Coronavirus OH found 4 nucleotide changes between fecal and nasal PRCV strains, two of which result in amino acid changes. When the isolated strains were compared with reference strains, one amino acid change was found in all strains and would suggest that the loss of the respiratory tropism of the fecal isolate could be a consequence of the change in this amino acid. Torovirus OH determined the prevalence, fecal shedding patterns and association of Bovine Torovirus with diarrhea in veal calves in 2 0H farms. Calves seronegative or with low antibody titers to BoTV at arrival seroconverted to BoTV and were more likely to shed virus than those already seropositive at arrival. Objective 2. Develop and improve diagnostics, treatment, and preventative measures for enteric and food borne diseases Brachyspira NE has developed a new method for differentiation of Brachyspira species of intestinal spirochetes by cellular fatty acid analysis. NE has also assessed the specificity of the serum IgG response in the context of recovery from and persistent infection by Brachyspira. Coronavirus KS tested the ability of unique commercial decontamination formulations to inactivate bovine coronoviruses as a model system for SARS-like viruses. Cryptosporidium IL has demonstrated that vegetative buffer strips dramatically reduce surface runoff and near-surface flow of oocysts as compared to bare soil surfaces for all rainfall intensities and soil slope conditions. Escherichia coli NE has conducted a clinical trial to test the effectiveness of vaccinating feedlot cattle against enterohemorrhagic E. coli O157:H7 type III secreted proteins on the proportion of feedlot steers shedding the respective organism in the feces. NE also conducted a clinical trial to test the effectiveness of feeding a Lactobacillus acidophilus direct-fed microbial to prevent feedlot cattle from shedding Escherichia coli O157:H7 in the feces. SD has assessed the distribution and significance of EAST1 genes in enterotoxigenic E. coli. The results were very similar to the reported prevalence of EAST1 in Asia and Europe and suggested that EAST1 may not be a major contributor to virulence in ETEC infection in young pigs. SD studied antibody repertoire development in fetal and neonatal piglets. Lawsonia intracellularis MN has evaluated the efficacy of hyper-immunized chicken eggs for the passive immunization protection of hamsters against LI challenge. MN also comparatively evaluated the efficacies of on-label, in-feed antimicrobials for control of PE. All three medications (BMD plus Aureomycin, Tylan, Lincomix) gave significant numerical reductions in the incidence and severity of ileal/jejunal lesions compared to the nonmedicated controls. None of the medications significantly affected seroconversion or the incidence of immuohistochemical-positive pigs. All treatments prevented any PE-related mortality, while 15% of the nonmedicated pigs died. In further studies, MN showed that carbadox inhibited the development of long-term immunity in pigs while protecting them from disease during initial inoculation. Newly Recognized Enteric Viruses and Caliciviruses OH generated recombinant baculoviruses expressing the capsid gene of a bovine norovirus and confirmed that the expressed protein self-assembled into VLPs. The ELISA developed detected BEC antibodies from BEC infected calves. Real-time PCR assays were developed by MI for rapid and sensitive diagnosis of the NB-BEC. Genetic characterization of MI and WI bovine noroviruses by MI based upon sequence analysis of a variable portion of the capsid gene showed that five were Jena-like and seven were NA-2-like. Rotavirus IL has demonstrated that a synthetic receptor mimec of the natural porcine rotavirus receptor, GM3 ganglioside, was able to protect pigs from diarrheal disease when given orally. NE, in collaboration with SDSU, characterized the specificity of hybridoma supernatants containing monoclonal antibodies directed against each of the five VP5* epitopes of bovine RV identified in previous studies. Brachyspira NE further developed a NADH oxidase gene PCR-based RFLP method for identification of Brachyspira from different hosts. NE also determined penicillin binding proteins (PBPs) are present in B. pilosicoli using ampicillin conjugated to digoxigenin and immunoblot chemiluminescent assays. Objective 3. Provide training and continuing education opportunities and dissemination of information MN has given presentations and updates on PE at various scientific, veterinary, and diagnostic meetings in the previous year. In addition, they have presented two international workshops, including theoretical lectures and practical laborabories, on the diagnosis and control of PE. The L. intracellularis  specific polyclonal and monoclonal antibodies have been made available to diagnostic laboratories and educational institutions for use in diagnosing PE. Students associated with the OH project are receiving training in the various research areas and with the pathogens specified. The techniques and primers for the RT-PCR assays for differentiation of PRCV and TGEV and detection of BoTV are being transferred to our state diagnostic veterinary laboratory for routine use. A talk on coronaviruses was presented to update veterinarians on bovine coronavirus and bovine torovirus enteric and respiratory disease problems in cattle in the field.

Publications jointly authored with other stations. Sargeant, J., and D. R. Smith. 2002. Chapter 15. The epidemiology of Escherichia coli O157:H7. In, Torrence, M.E. and R.E. Isaacson (eds.), Microbial Food Safety in Animal Agriculture: Current Topics. Iowa State University Press, pp. 131-141. Publications Berberov, E.M., Y. Zhou, D.H. Francis, M.A. Scott, S.D. Kachman, and R.A. Moxley. 2003. Relative importance of heat-labile enterotoxin in the causation of severe diarrheal disease in the gnotobiotic piglet model by a strain of Escherichia coli that produces multiple enterotoxins. Infection and Immunity (submitted) Bergner, D., TB Kuhlenschmidt and MS Kuhlenschmidt . Characterization of a Synthetic Receptor Mimetic for Group A Porcine Rotavirus (submitted). Burkey TE, Dritz SS, Nietfeld JC, Minton JE. Effect of dietary mannanoligosaccharide and sodium chlorate on the growth performance, acute phase response and bacterial shedding of weaned pigs challenged with Salmonella enterica Serotype Typhimurium. J Anim Sci (submitted). Butler, J.E., P. Weber, M. Sinkora, D. Baker, A. Schoenherr, B. Mayer and D. Francis. 2002. Antibody repertoire development in fetal and neonatal piglets. VIII. Colonization is required for newborn piglets to make serum antibodies to T-independent and type 2 T-independent antigens. J. Immunology. 169: 6822-6830. Chang, K.O., Y. Kim, K.Y. Green and L.J. Saif. 2002. Cell culture propagation of porcine enteric calicivirus mediated by intestinal contents is dependent on the cyclic AMP signaling pathway. Virology 304:302-310. Duhamel, G.E., C.J. Stryker, G. Lu, V.J. Wong, and R.P. Tarara. 2003. Colonic spirochetosis of colony-raised rhesus macaques associated with Brachyspira and Helicobacter. Anaerobe 9:45-55. Guedes, RM.C. and GebhaIt, C.J. 2003. Preparation and characterization of polyclonal and monoclonal antibodies against Lawsonia intracellularis. J. Vet. Diag. Investi. 15:438 446. Guedes, RM.C. and Gebhart, C.J. 2003. Comparison of pure culture of Lawsonia intracellularis and intestinal mucosa homogenate as challenge models for porcine proliferative enteropathy. Vet. Microbiol. 93:159 166 Guedes, RM.C. and Gebhart, C.J. 2003. Onset and duration of fecal shedding, cell mediated and humoral immune responses after challenge with a pathogenic isolate or a commercial vaccine of Lawsonia intracellularis. Vet. Microbiol. 91:135 145. Guedes, R.M.C., Winkelman, N L., and Gebhart, C.J. 2003. Relationship between the severity of porcme proFferative enteropathy and the infectious dose of Lawsonia intracellualaris. Vet. Rec. 153:432 433. Guo, M. and L.J. Saif. 2002. Pathogenesis of enteric calicivirus infections. In Viral Gastroenteritis, (U. Desselberg and J. Gray, eds.) Elsevier Science, Amsterdam, The Netherlands, pp. 489-504. Guo, M., J. Vinje and L.J. Saif. 2002. Caliciviruses and other potential foodborne viruses. In Current Topics in Food Safety in Animal Agriculture, (R. Isaacson and M.E. Torrence, eds.), Iowa State Univ. Press, Ames, Iowa, pp. 333-350. Johnson, JK, Schmidt, J,Gelberg, HB and Kuhlenschmidt MS. (2004) Microbial Adhesion of Cryptosporidium parvum sporozoites: Purification of an Inhibitory Lipid from Bovine Mucosa. J. Parasitol. (in press) Khaitsa, M.L, D.R. Smith, J.A. Stoner, A.M. Parkhurst, S. Hinkley, T.J. Klopfenstein, and R.A. Moxley. 2003. Incidence, duration and prevalence of Escherichia coli O157:H7 fecal shedding by feedlot cattle during the feeding period. Journal of Food Protection 66:1972-1977 Maes, R. K., D.L. Grooms, A.G. Wise, C. Han, V. Ciesicki, L.Hanson, M.L. Vickers and R. Holland. 2003. Evaluation of a Group A Rotavirus Assay for On-Site Detection of Bovine Rotavirus. J. Clin. Micro. 41; 290-294 Marsteller T.A., Annbruster, G., Bane, D.P., Gebhart, C.J., et al. 2003. Monitoring the prevalence of Lawsonia intracelluiaris IgG antibodies using serial sampling in grow~mg and breeding swine herds. J. Swine Health and Prod. 11:127 130. Moreno B, Bailey BN, Luo S, Martin MB, Kuhlenschmidt M, Moreno SN, Docampo R, Oldfield E. (2001) (31)P NMR of apicomplexans and the effects of risedronate on Cryptosporidium parvum growth. Biochem Biophys Res Commun. 284:632-7 Potter, A.A., S. Klashinsky, Y. Li, E. Frey, H. Townsend, D. Rogan, G. Erickson, S. Hinkley, T. Klopfenstein, R.A. Moxley, D.R. Smith, and B.B. Finlay. 2004. Decreased shedding of Escherichia coli O157:H7 by cattle following vaccination with type III secreted proteins. Vaccine Vol. 22, issues 3-4 (In press) Raphael, B.H. and L.A. Joens, 2004. Ferrous lron Uptake if Independent of FeoB in Campylobacter jejuni. Can. J. of Micro. In press. Ristevski, B., Young, A.J., Dudler, L., Cahill, R.N.P., Kimpton, W., Washington, E., Hay, J.B. (2003) Instantaneous labeling of the total blood leukocyte pool to track the development and migration of rare cell types in vivo. International Immunol. 15(2):159-165. Secomb, T.W., Konderding, M.A., West, C.A., Su, M., Young, A.J., Mentzer, S.J. (2003) Microangiectasias: Structural regulators of lymphocyte transmigration in inflammatory skin. Proc. Nat. Acad. Sci. 100(12):7231-7234. Smith, D.R., J. Gray, R. Moxley, S. Younts, M. Blackford, S. Hinkley, L. Hungerford, T. Milton, T. Klopfenstein. 2004. A novel diagnostic strategy to classify feedlot pens by the percentage of cattle shedding Escherichia coli O157:H7. Epidemiology and Infection (in press) Su, M., West, C.A., Young, A.J., He, C., Konerding, M.A., Mentzer, S.J. (2003) Dynamic deformation of migratory efferent lymph-derived cells "trapped" in the inflammatory microcirculation. J. of Cell. Physiol. 194(1):54-62. Trask, JR, Kalita, PK, Kuhlenschmidt, MS, Smith, RD and TL Funk. Overland and Near-surface Transport of Cryptosporidium parvum. 2004. Environ. Qual. (in press) Wise, A.G., S.S. Monroe, L.E. Hanson, D.L. Grooms, D. Sockett and R.K. Maes. 2003. Molecular characterization of noroviruses detected in diarrheic stools of Michigan and Wisconsin dairy calves: Circulation of two distinct subgroups. (submitted). Young, A.J., Holzgreve, W., Dudler, L., Schoeberlein, A., Surbek, D. (2003) Engraftment of human cord blood-derived stem cells in preimmune ovine fetuses after ultrasound-guided in- utero transplantation. .Am. J. Gynecol. Obstet. (In Press) Theses Burkey TE. Effect of dietary mannanoligosaccharide and sodium chlorate on the growth performance, acute phase response and bacterial shedding of weaned pigs challenged with Salmonella enterica Serotype Typhimurium. Thesis for Master of Science. Department of Animal Sciences and Industry, Kansas State University, Manhattan, KS 2003. Brands, D.A. 2003. Thesis. The prevalence and molecular characterization of Salmonella spp. in oysters. University of Arizona, Tucson. Lee, M.K. 2003. Thesis. Presence, potential virulence and antibiotic susceptibility of Campylobacter jejuni isolated from food and companion animals. University of Arizona, Tucson. Pitts, T.M. 2001. Thesis. Intra-macrophage survival of Carn~ylobacter jejuni and maturation of C. jejuni containing phagosomes. University of Arizona, Tucson. Raphael, B.H.. 2002 Thesis. Iron uptake systems of Campylobacter jejuni. University of Arizona, Tucson. Zhang, R., MS Thesis, 2003, University of Nebraska-Lincoln, Comparative analysis of membrane proteins of human and animal Brachyspira species. Book Chapters: Moxley, R.A. 2003. Detection and diagnosis of Escherichia coli O157:H7 in food-producing animals. In, Torrence, M.E. and R.E. Isaacson (eds.), Microbial Food Safety in Animal Agriculture: Current Topics. Iowa State University Press, pp. 143-154. Abstracts/Proceedings: Al Ghamdi, G.M., R.M.C. Guedes, T.R Ames, and C.J. Gebhart. 2002. Reproduction of proliferative enteropathy in foals after challenge with Lawsonia intracellularis infected porcine mtestinal mucosa homogenate. Proc. 83rd Conf. Res. Workers An. Dis., St. Louis, MO, November 10 12 Alsop, J., J. Harding, V. Costantini, P. Lewis and L.J. Saif. A trial to determine true TGE status in a multiplier herd. Int. Pig Vet. Symposium, Ames, IA, June 2-5, 2002. Baker, D.R., R.A. Moxley and D.H. Francis. 2003. Amount of Shiga toxin type 2 (Stx2) expressed by Escherichia coli O157:H7 strains in vitro is correlated with virulence in the gnotobiotic piglet model. Proceedings, 84 Annual Meeting of the Conference of Research Workers in Animal Diseases. Chicago, IL. Beckler, D.C., C. Mahlum Wees, RM.C. Guedes, and C.J. Gebhart. 2003. Development and comparison of tests for detecting fecal shedding of Lawsonia intracellularis. 34th Annual Mtg. Am. Assoc. Swine Veterinarians, March 8 11, Orlando, FL. Carvajal, A., M.L. De Arriba, H. Rodriguez, A.B. Vidal, G.E. Duhamel, and P. Rubio. 2003. Prevalence of Brachyspira hyodysenteriae and B. pilosicoli infections among spanish swine herds with diarrhoea. 2nd International Conference on Colonic Spirochaetal Infections in Animals and Humans, Edinburgh, United Kingdom, April 2-4, p. 43. Chang, K-O., S. Sosnovtsev, G. Belliot, L.J. Saif, and K.Y. Green. 2003. Generation and characterization of infectious RNA transcripts of porcine enteric calicivirus in cell culture. 22nd Annual Meeting of the Conference of American Society for Virology, Davis, CA, Abst. July 12-16, 2003. Costantini, B., F. Loisy, J. Joens, F. LeGuyader and L.J. Saif. Calicivirus survey in U.S. Market oysters: preliminary findings. 22nd Annual Meeting of the Conference of American Society for Virology, Davis, CA, Abst. July 12-16, 2003. Dassanayake, R.P., N.E. Caceres, G. Sarath, and G.E. Duhamel. 2003. Biochemical properties of membrane-associated proteases of Brachyspira pilosicoli isolated from humans with intestinal disorders. 2nd International Conference on Colonic Spirochaetal Infections in Animals and Humans, Edinburgh, United Kingdom, April 2-4, p. 37. Dassanayake, R.P., G. Sarath, and G.E. Duhamel. 2003. Identification of penicillin-binding proteins (PBPs) in membrane extracts of Brachyspira pilosicoli. 84th Annual Meeting Conference Research Workers in Animal Diseases, St. Louis, Missouri, November 9-11, P (Poster). Duhamel, G.E. 2003. Diagnostic procedures for colonic spirochaetal infections, where have we been and where are we going? 2nd International Conference on Colonic Spirochaetal Infections in Animals and Humans, Edinburgh, United Kingdom, April 2-4, p.13. Duhamel, G.E., and K. Tarasiuk. 2003. Phenotypic and genotypic characterization of Brachyspira pilosicoli isolated from humans with intestinal disorders. 2nd International Conference on Colonic Spirochaetal Infections in Animals and Humans, Edinburgh, United Kingdom, April 2-4, p. 27. Duhamel, G.E., T.K. Jensen, M. Boye, and K. Møller. 2003. Comparative pattern of spirochetal colonization in naturally-occurring swine dysentery and porcine colonic spirochetosis. 2nd International Conference on Colonic Spirochaetal Infections in Animals and Humans, Edinburgh, United Kingdom, April 2-4, p. 48. Duhamel, G.E., K. Sestak, C.J. Stryker, G. Lu, and A.A. Lackner. 2003. Colonic spirochetosis of colony-raised rhesus macaques is a polymicrobial disease associated with multiple species of Brachyspira and Helicobacter. 84th Annual Meeting Conference Research Workers in Animal Diseases, St. Louis, Missouri, November 9-11, O (Oral). Duhamel, G.E., C. Fellström, C.J. Stryker, M. Alexander, A. Gunnarsson, and G. Osterhout. 2003. Characterization of canine Brachyspira by cellular fatty acid analysis and pulse-field gel electrophoresis. 2nd International Conference on Colonic Spirochaetal Infections in Animals and Humans, Edinburgh, United Kingdom, April 2-4, p. 34. Duhamel, G.E., C.J. Stryker, and Y.J. Zhou. 2003. Demonstration of Brachyspira pilosicoli association with canine colonic spirochetosis and B. canis as a non-pathogenic commensal. 2nd International Conference on Colonic Spirochaetal Infections in Animals and Humans, Edinburgh, United Kingdom, April 2-4, p. 20. Duhamel, G.E., L. Ganley, B.C. Barr, J.P. Whipple, R.W. Nordhausen, R.L. Walker, and H.J. Van Kruiningen. 2003. Colonic spirochetosis of North American opossums (Didelphis virginiana): A potential reservoir of infection for humans and animals. 2nd International Conference on Colonic Spirochaetal Infections in Animals and Humans, Edinburgh, United Kingdom, April 2-4, p. 42. Fegan N, Higgs GM, Vanderlinde P, Desmarchelier P, Smith DR. 2003. Pen test devices for detection of E. coli O157 and Salmonella in cattle. VTEC 2003. Edinburgh, Scotland, UK. June 8-11, 2003. Poster Folmer, J., C. Macken, R. Moxley, D. Smith, M. Brashears, S. Hinkley, G. Erickson, and T. Klopfenstein. 2003. Intervention strategies for reduction of E. coli O157:H7 in feedlot steers. 2003 Nebraska Beef Report. Agricultural Research Division, University of Nebraska Cooperative Extension, Institute of Agriculture and Natural Resources, University of Nebraska-Lincoln, pp. 22-23, http://animalscience.unl.edu/beef/beef.htm. Gebhart, C J., Winkolmm, N, Deen, J , and Gramm~ B. 2003. Development of mmmity to Lawsonia intracellulans in pigs fed carbadox. 34th Aunual Mtg. Am. Assoc. Swine Veterinarians, March 8 11, Orlando, FL. Gebhart, C.J., L.L. Li, Q. Zhang, L.L. Heron, and V. Kapur. 2002. A genomic sequence survey of Lawsonia intracellularis identifies numerous genes of relevance to diagnosis, virulence, and immunoprophylaxis. Proc. 83rd Conf. Res. Workers An. Dis., St. Louis, MO, November 10 12. Graybill, M.D., Elmubaruk, G., DeRycke, M.S., Young, A.J. 2003. Role of soluble CD14 in the regulation of neonatal ovine B cell differentiation and expression. Proceedings, Autumn Immunology Conference. Chicago, IL Guedes, RM.C. and C.J. Gebhart. 2003. Progression of Lawsonia intracellularis infection and mucosa immune response in pigs. 34th Annual Mtg. Am. Assoc. Swine Veterinarians, March 8 11, Orlando, FL. Guedes, R.M.C., C. J. Gebhart, and G.A. Armbruster. 2002. Progression of Lawsonia intracellularis infection in experimentally infected pigs. Proc. 83rd Conf. Res. Workers An. Dis., St. Louis, MO, November 10 12. Guedes, R.M.C. and C.J. Gebhart. 2002. Production and characterization of new polyclonal and monoclonal antibodies for Lawsonia intracellularis. 29th Allen D. Leman Swine Conference, Minneapolis, MN, September 15 17. Gwyn, C.B., and G.E. Duhamel. 2003. Porcine colonic spirochetosis caused by Brachyspira pilosicoli. Swine Health Symposium, Stratford, Ontario, Canada, May 16-18, p. 5-12. Han, M.G., Q. Wang, J.R. Smiley and L.J. Saif. 2003. Self-assembly of recombinant capsid proteins of a bovine norovirus into virus-like particle (VLP). 22nd Annual Meeting of the Conference of American Society for Virology, Davis, CA, Abst. July 12-16, 2003 Hoet, A.E., S. Sreevatsan and L.J. Saif. Molecular analysis of the 5' end of the spike gene of bovine torovirus (breda virus) field strains. Am. Soc. Virol., Lexington, KY, July 20-24, 2002. Johansson, K.E., G.E. Duhamel, B. Bergsjö, E.E. Olsson, M. Persson, B. Pettersson, and C. Fellström. 2003. Phylogeny of canine intestinal spirochetes based on 16S rDNA analysis. 2nd International Conference on Colonic Spirochaetal Infections in Animals and Humans, Edinburgh, United Kingdom, April 2-4, p. 33. Kinsley, K., C. J. Gebhart, N. WinkeEnan, and R.M.C. Guedes. 2003. Passive immunization of hamsters using hyperimmunized chicken eggs to control Lawsonia intracellularis infection: a model for growing swine. 34th Aonual Mtg. Am. Assoc. Swine Veterinarians, March 8 11, Orlando, FL. Kolappaswamy, K., Y.J. Zhou, and G.E. Duhamel. 2003. Attachment of Brachyspira pilosicoli to cultured intestinal epithelial cell lines. 34th Midwest Student Biomedical Research Forum, Omaha, Nebraska, February 21-22, P-14 (Poster). Moxley1, R.A., D. R. Smith1, T. J. Klopfenstein2, J. D. Folmer2, C. N. Macken2, G. E. Erickson2, S. Hinkley1, A. A. Potter3, and B. B. Finlay4. 2003. Vaccination and direct-fed microbials as intervention strategies to reduce the prevalence of Escherichia coli O157:H7 in feedlot cattle. 1Dept. of Vet. & Biomed. Sci., 2Dept. of Animal Sci., U. of Nebraska, Lincoln, NE. 3Vaccine & Infectious Disease Org., U. of Saskatchewan, Saskatoon, Saskatchewan, Canada. 4Biotechnology Laboratory, U. of British Columbia, Vancouver, BC, Canada. 84th Annual Meeting Conference Research Workers in Animal Diseases, Chicago, Illinois, Nov. 9-11. Abstract 82 (Oral). Moxley, R.A. 2003. Escherichia coli O157:H7: an update on intestinal colonization and virulence mechanisms. Dept. of Vet. & Biomed. Sci., U. of Nebraska, Lincoln, NE. 84th Annual Meeting Conference Research Workers in Animal Diseases, Chicago, Illinois, Nov. 9-11. Abstract 92 (Oral, keynote). Nielsen, P.R., Y. Kim, K.O. Chang and L.J. Saif. Passive protection of neonatal calves against challenge with bovine rotavirus by colostrum supplements from cows vaccinated with a combination of bovine rotavirus-like particles against one or both prevalent U.S. serotypes. Conference for Research Workers in Animal Disease. St. Louis, MO, November 10-12, 2002. Rice MA, Fang Y, Ambagala APW, Ambagala TC, Srikumaran S, Nelson EA, Duhamel GE. 2003.Characterization of monoclonal antibodies specific for linear B-cell epitopes located within bovine group A rotavirus VP5* . 84th Annual Meeting Conference Research Workers in Animal Diseases, St. Louis, Missouri, November 9-11, P (Poster). Rohlik, A., DeRycke, M., Young, Alan J. 2003. Identification and Characterization Of Leukocyte Populations In Hoofstock; A tool for the study of Chronic Wasting Disease (CWD) Proceedings, Autumn Immunology Conference. Chicago, IL Ruesch, L.L., R.L. VanderVeen and D.H. Francis. 2003. Enteroaggregative Escherichia coli heat-stable enterotoxin 1 (EAST1) and its occurrence in enterotoxigenic E. coli strains causing diarrheal disease. Proceedings, 84 Annual Meeting of the Conference of Research Workers in Animal Diseases. Chicago, IL. Saif, L.J., M. Guo and J. Smiley. Enteric caliciviruses in pigs and calves and their relationship to human caliciviruses. Brazil Soc. 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Association of bovine torovirus with veal calf diarrhea. Conference for Research Workers in Animal Disease. St. Louis, MO, November 10-12, 2002. Trask, JR, Kalita, PK, Kuhlenschmidt, MS, Smith, RD and TL Funk. Overland and Near-surface Transport of Cryptosporidium parvum. 2001. Annual American Society For Agricultural Engineering, Paper Number 01-2104. Wang, Q.H., M.G. Han, A.E. Hoet, and L.J. Saif. Hemagglutination by Cowden porcine enteric calicivirus and development of hemagglutination-inhibition test. Conference for Research Workers in Animal Disease. St. Louis, MO, November 10-12, 2002. Wang Q.H., M. Guo and L. J. Saif. 2003. Serum neutralizing and isotype antibody responses in gnotobiotic (Gn) pigs inoculated orally with tissue culture-adapted (TC) or wild type (WT) porcine enteric calicivirus (PEC). 22nd Annual Meeting of the Conference of American Society for Virology, Davis, CA, Abst. July 12-16, 2003. Ward, J.J., RD. Smith, MS Kuhlenschmidt. 2002. Evaluation of Factors Contributing to Environmental Contamination with Cryptosporidium parvum from a Dairy Herd. International Conference on Emerging Infectious Diseases, March 2002, Atlanta, Ga. Whitney, M.H., G.C. Shurson, R.M.C. Guedes, and C.J. Gebhart. 2002. The relationship between distiller's dried grains with solubles (DDGS) and ileitis. Min. Nutrition Conf ~ Pre Conf Symposium: Rendering a foundation for food security. Eagan, MN, p.244 256. Winkelman, N., Gebhart, C.J., Wolff, T., and Skinner, J. 2003. An evaluation of BMD plus Aureomycm chlortetracycline (CTC), Tylan or Lmcomix for control of challenge induced PPE m swine. 34th Annual Mtg. Am. Assoc. Swme Veterioarians, March 8 11, Orlando, FL. Winkehman, N., Gebhart, C.J., Deen, J., and Gramm, B. 2003. Correlation of clinical signs and diagnostic indicators of ileitis in pigs fed carbadox. 34th Aunual Mtg. Am. Assoc. Swine Veterinarians, March 8 11, Orlando, FL Wise, A. G., L. Hanson, D. Grooms and R. Maes. 2002. Detection and molecular characterization of bovine Norwalk-like viruses in diarrheie stools collected from Michigan and Wisconsin dairy calves. Proc. of the American Association of Veterinary Laboratory Diagnosticians 45th Annual Meeting, St. Louis, MO 2002. p. 9. Young, A.J., Richt, J., Hamir, A. 2003. A potential role for B cell subsets in the pathogenesis of Prion Disease. Proceedings, 84 Annual Meeting of the Conference of Research Workers in Animal Diseases. Chicago, IL. Zhang, W., J. Freeling, E. Berberov, R. Moxley and D. Francis. 2003. Development of a model for the assessment of the contributions of E.coli enterotoxins to the pathogenesis of porcine colibacillosis. Proceedings, 84 Annual Meeting of the Conference of Research Workers in Animal Diseases. Chicago, IL. Zhang, R., and G.E. Duhamel. 2003. Comparative analysis of pathogenic and commensal porcine Brachyspira species membrane proteins. 2nd International Conference on Colonic Spirochaetal Infections in Animals and Humans, Edinburgh, United Kingdom, April 2-4, p. 46.