University of Guelph

About: University of Guelph is a education organization based out in Guelph, Ontario, Canada. It is known for research contribution in the topics: Population & Gene. The organization has 26542 authors who have published 50553 publications receiving 1715255 citations. The organization is also known as: U of G & Guelph University.

Antimicrobial resistance in Escherichia coli isolates from swine and wild small mammals in the proximity of swine farms and in natural environments in Ontario, Canada.

Abstract: Wild animals not normally exposed to antimicrobial agents can acquire antimicrobial agent-resistant bacteria through contact with humans and domestic animals and through the environment. In this study we assessed the frequency of antimicrobial resistance in generic Escherichia coli isolates from wild small mammals (mice, voles, and shrews) and the effect of their habitat (farm or natural area) on antimicrobial resistance. Additionally, we compared the types and frequency of antimicrobial resistance in E. coli isolates from swine on the same farms from which wild small mammals were collected. Animals residing in the vicinity of farms were five times more likely to carry E. coli isolates with tetracycline resistance determinants than animals living in natural areas; resistance to tetracycline was also the most frequently observed resistance in isolates recovered from swine (83%). Our results suggest that E. coli isolates from wild small mammals living on farms have higher rates of resistance and are more frequently multiresistant than E. coli isolates from environments, such as natural areas, that are less impacted by human and agricultural activities. No Salmonella isolates were recovered from any of the wild small mammal feces. This study suggests that close proximity to food animal agriculture increases the likelihood that E. coli isolates from wild animals are resistant to some antimicrobials, possibly due to exposure to resistant E. coli isolates from livestock, to the resistance genes of these isolates, or to antimicrobials through contact with animal feed.

Severe acute bovine viral diarrhea in Ontario, 1993-1995

Abstract: In 1993, noncytopathic bovine viral diarrhea virus (BVDV) strains with enhanced virulence caused unprecedented outbreaks of severe acute bovine viral diarrhea (BVD) in dairy, beef, and veal herds in Ontario (Canada). Fever, pneumonia, diarrhea, and sudden death occurred in all age groups of cattle. Abortions often occurred in pregnant animals. Gross lesions in the alimentary tract were similar to those associated with mucosal disease, especially in animals .6 months of age. Cattle of all age groups had microscopic lesions in the alimentary tract similar to those seen with mucosal disease. The epidemic peaked in the summer of 1993, with 15% of all bovine accessions from diseased cattle presented to the diagnostic laboratory being associated with BVDV. The virus strains involved in the outbreak were analyzed using monoclonal and polyclonal anti- bodies and the polymerase chain reaction. The virus isolates from these outbreaks of severe disease were determined to be type 2 BVDV. Type 2 BVDV has been present in Ontario at least since 1981 without causing widespread outbreaks of severe acute BVD, which suggests that type 2 designation in itself does not imply enhanced virulence. Cattle properly vaccinated with type 1 BVDV vaccines appear to be protected from clinical disease. Bovine viral diarrhea (BVD) was originally de- scribed in 1946 16 in New York State as an acute, rarely fatal, highly contagious disease with fever, diarrhea, mucosal lesions, and leukopenia. Although initial re- ports described a clinically severe disease, acute BVD has since been considered a mild or subclinical disease of a few days duration, with negligible mortality at any age. 11,22 Occasionally, scattered outbreaks of se-

‘Proactive fast-tracking’ diffusion of supermarkets in developing countries: implications for market institutions and trade

Abstract: Supermarkets have spread extremely rapidly in developing countries after the ‘take-off’ in the early to mid-1990s. Former analyses of supermarket diffusion have not adequately explained the sudden burst and then exponential diffusion of supermarkets in the late 1990s and early 2000s. We argue that rather than taking demand and market institutional and organizational conditions as ‘exogenous’, as former analyses have tended to do, modern food retailers instead have treated local conditions as substantially ‘endogenous’. To enable their rapid growth, supermarkets undertake ‘proactive fast-tracking strategies’ to alter the ‘enabling conditions’ of entry and growth. Beside the retail investments that have been extensively treated in recent literature, these proactive strategies focus on improving the ‘enabling conditions’ via (i) procurement system modernization and (ii) local supply chain development. One important strategy retailers have used to facilitate (i) and (ii) is to form symbiotic relationships with modern wholesale, logistics and processing firms. An example we address is ‘follow sourcing’, where a transnational retailer encourages transnational logistics and wholesale firms with whom the retailer is working in home markets, to locate to the developing country. This is a spur to globalization of services in support of retail. Follow-sourcing has been treated for example in the automobile manufactures sector (follow-sourcing from spare parts manufacturers)—but not in the food sector. A second important strategy is that of multi-network-sourcing, in which supermarkets source from national, regional and global networks. We analyze that strategy here, adding to the literature which to date has touched on this theme only scantly, and for the first time identify typical paths, present preliminary evidence (from Central America and Indonesia) concerning this multi-sourcing-network strategy and discuss trade implications. One of these is the move to primacy of South–South trade in supermarket sourcing—a new dimension of globalization. By introducing this link of retailer transformation and trade into the literature, we hope to spur a new line of research that is timely in light of the trade, development and globalization debates in developing countries.

An Eimeriid origin of isosporoid coccidia with Stieda bodies as shown by phylogenetic analysis of small subunit ribosomal RNA gene sequences.

Abstract: Morphological and life cycle features of the tissue cyst-forming coccidia have been difficult to interpret in devising taxonomic classifications for the various genera. In this study, we amplified the full small subunit rRNA gene sequence of Isospora robini McQuistion and Holmes, 1988, and the partial sequence of Isospora gryphoni Olsen, Gissing, Barta, and Middleton, 1998 by PCR. Both of these species vary from Isospora species of mammals in having Stieda bodies on the sporocysts. The sequences were cloned and sequenced and were incorporated into an alignment with other Isospora species lacking Stieda bodies as well as with other coccidia. Maximum parsimony analysis of these sequences produced a single most parsimonious tree that placed I. robini and I. gryphoni in a clade containing various other eimeriid species. The Isospora species lacking Stieda bodies were in the sarcocystid clade. Similar results were found by maximum likelihood analysis. These findings indicate that the genus Isospora as defined by several authors is polyphyletic. Taxonomic changes to the genus Isospora would have to incorporate the 2 major clades found by molecular phylogenetic analysis. Isospora species with Stieda bodies should be classified in the family Eimeriidae, whereas those without Stieda bodies should remain in the family Sarcocystidae.