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Organophosphate (OP) acaricide resistance in Boophilus microplus ticks compromises the efficacy of tick control programs. Mechanisms that may contribute to acaricide resistance were evaluated by partial characterization of three OP-resistant B. microplus tick cell lines (C34, C44, and C54) compared to nonresistant control cells. The resistant cells showed an increase in glutathione coupled with a decrease in glutathione S-transferase activity, decreased plasma and mitochondrial membrane potentials, increased intracellular calcium concentration, and increased esterase levels. These results are consistent with resistance mechanisms found in other cell systems and with in vivo observations of increased esterase activity in organophosphate-resistant ticks. No significant differences were found in intracellular pH, drug efflux, or reactive oxygen species. The use of organophosphate-resistant cell lines offers a convenient vehicle for studying mechanisms of acaricide resistance development in vitro. [Copyright &y& Elsevier]

Escherichia coli O157:H7, an emerging cause of food-borne disease with the occurrence of an estimated 20,000 illnesses and 250 deaths each year in the United States, has now been reported from several countries worldwide. Infections with this bacteria, which follows the ingestion of contaminated food by humans, causes bloody diarrhea, hemolytic uremic syndrome (HUS), and renal disease, that can have serious health implications. The source of food contamination is usually associated with animals, mainly cattle. Many cattle become infected early in life when they are exposed to an environment that is contaminated by other animals shedding the organisms in their feces. Detection of E. coli O157:H7 in feces or contaminated food samples requires tests with high sensitivity, which is increased by the use of monoclonal antibodies. However, the production of concentrated monoclonal antibodies in ascites raises animal welfare concerns, and can be expensive. In this study, single chain of variable fragment (scFv) molecules were developed from hybridoma clones that produce immunoglobulins specific for the LPS and flagella antigen of E. coli O157:H7 using phage display technology. The reactivity of the soluble scFv for their respective antigens was preserved in ELISA and by partial inhibition of bacterial agglutination with polyclonal antiserum. Furthermore, the scFv were able to capture E. coli O157:H7 bacteria demonstrating their potential use in diagnostic assays.

Suppose one of your clients from southern Florida starts talking about cattle egrets while you are vaccinating her cat. It seems she found a nearly dead egret near the cattle pen a few days ago, picked it up, and noticed a number of what looked like small ticks on the legs. Or, suppose you are called out to a small dairy in central Texas to look at some cows that are feverish and anemic. The first animal you examine has a few brown ticks attached just under the tail. Finally, perhaps you are looking at a lame tortoise for a reptile fancier, a new client, and find a large, colorful tick on a hind leg, well up under the shell. Ring any bells? Egrets are great hosts for the immature stages of Amblyomma ticks and have been captured and marked in the eastern Caribbean, then recaptured in the Florida Keys. Those cattle ticks in Texas might be acaricide-resistant Boophilus ticks that originated in Mexico. The Amblyomma tick on the tortoise could well have "hitch-hiked" all the way from South Africa. By now you remember that both Amblyomma and Boophilus ticks are efficient vectors of two tickborne diseases in this hemisphere, heartwater (in the case of Amblyomma) and babesiosis (transmitted by Boophilus ticks). Both of these diseases are exotic to the United States, and because our livestock are considered to be totally susceptible, an introduced infection could result in high initial death losses (approximately 70%); thus, both the ticks and the diseases pose immediate threats to the health and economic security of United States animal industries. Most importantly, you, whether as a small animal or large animal practitioner, are the first line of defense against such exotic diseases and their vectors.

The public needs no reminder that deadly infectious diseases such as FMD could emerge in any country at any moment, or that national food security could be compromised by Salmonella or Listeria infections. Protections against these risks include the knowledge that appropriate and equivalent veterinary education will enable detection and characterization of emerging disease agents, as well as an appropriate response, wherever they occur. Global veterinary leadership is needed to reduce the global threat of infectious diseases of major food animal and public health importance. We believe that the co-curriculum is an excellent way to prepare and train veterinarians and future leaders who understand and can deal with global issues. The key to the success of the program is the veterinarian's understanding that there is a cultural basis to the practice of veterinary medicine in any country. The result will be a cadre of veterinarians, faculty, and other professionals who are better able (language and culture) to understand the effects of change brought about by free trade and the importance of interdisciplinary and institutional relationships to deal effectively with national and regional issues of food safety and security. New global veterinary leadership programs will build on interests, experience, ideas, and ambitions. A college that wishes to take advantage of this diversity must offer opportunities that interest veterinarians throughout their careers and that preferably connect academic study with intensive experiential training in another country. At its best, the global veterinary leadership program would include a partnership between veterinarians and several international learning centers, a responsiveness to the identified international outreach needs of the profession, and attention to critical thinking and reflection. The global veterinary leadership program we have described is intended to be a set of ideas meant to promote collaboration, coalitions, and discussion among veterinarians and veterinary educators who may be intrigued by the concept. The impact of the program can be summarized as follows: Outreach Programs: The global veterinary leadership program will establish new partnerships between veterinarians and veterinary college faculty as they supervise the international internships and see a relationship between their goals and the value of food safety to this country. Strategic Opportunity: The program will build on the critical role that US veterinarians and veterinary colleges already play in strengthening the safety of free trade in this hemisphere. Diversity in an Age of Specialization: The program will combine a global orientation, language ability, and access to comprehensive, research- and economic-related work/study opportunities to expose veterinarians to the expanding world market for veterinary expertise. New Linkages Through Corporate Partners: Through the success and high visibility of current research and education programs, most veterinary colleges are well positioned to engage industry, government, and university leaders in ways to use the proposed program to increase the flow of new ideas and talent into the world food enterprise. International Funding: A new partnership among veterinarians, industry, government, and university leaders can coordinate strong multilateral requests for funding from national and international sources. An Interdisciplinary Strategy that Benefits Veterinary Medicine: The program will combine the diverse veterinary research and education system with our strong national and international network of collaborators to provide globally competent veterinarians who will be needed for the corporate and public opportunities of the future.