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Pathogenesis of chronic gastritis in an animal model of helicobacter infection
270
ESVP/ECVP Proceedings 2009
141:4, 2009
3
4
COMPARISON OF THE PATHOLOGY OBSERVED IN LAMBS AND ADULT SHEEP EXPERIMENTALLY INFECTED WITH MYCOBACTERIUM AVIUM SUBSP. PARATUBERCULOSIS L. Delgado, M. Mun˜oz, C. Garcı´a-Pariente, M. Fuertes, J. Benavides, J. Gonza´lez, M. Ferreras, V. Pe´rez and J.F. Garcı´a Marı´n IGM-CSIC-ULE, Department of Animal Health, University of Leo´n, Spain Introduction: The objective of this study was to evaluate the susceptibility of adult sheep to Mycobacterium avium subsp. paratuberculosis (Map) infection using different doses of Map. Materials and Methods: 24 lambs and 22 adult sheep were orally infected with two doses of Map (1010 and 103 CFU). Fourteen animals remained as uninfected controls. The animals were necropsied at 120 and 210 days post-infection. Numbers of granulomas were counted and the severity of lesions was evaluated in samples of intestine and associated lymphoid tissue. Peripheral cellular immune response was assessed fortnightly. Results: No gross lesions were observed in any of the animals. Microscopical lesions of paratuberculosis were detected only in the high dose-infected groups. Adult sheep showed small, demarcated focal granulomas restricted to areas of lymphoid tissue. Lesions were larger, more numerous and extended to the lamina propria in the lambs. The peripheral IFN-g response appeared earlier in the adult sheep than in the lambs. Conclusions: These results indicate the possibility of infection and development of characteristic lesions of paratuberculosis in adult sheep. Adult sheep seem better able to control the progression of the disease than lambs.
PATHOGENESIS OF CHRONIC GASTRITIS IN AN ANIMAL MODEL OF HELICOBACTER INFECTION B. Flahou, S. Kumar, K. Van Deun, M. Vermoote, K. Chiers, F. Pasmans, F. Haesebrouck and R. Ducatelle Faculty of Veterinary Medicine, Ghent University, Belgium Introduction: The role of Helicobacter spp. other than H. pylori in the development of gastric pathology in domestic animals is unclear. Recently, we isolated and characterized Helicobacter suis from the gastric mucosa of pigs. Materials and Methods: Mongolian gerbils were experimentally infected with the newly described species H. suis. The development of gastric pathology was studied microscopically at different time intervals after infection. Results: From 3 weeks after infection onwards, bacterial colonization of the antrum was associated with gradually increasing infiltrations of T and B lymphocytes in the propria mucosae, extending into the submucosa and the tunica muscularis at later stages. The germinal centres of the lymphoid follicle-like structures were expanded. Simultaneously, there was a mild loss of parietal cells at the transition zone between fundus and antrum and an expansion of the dividing epithelial cell population. Ultrastructurally, the helically shaped bacteria were found in close association with parietal cells and in debris of necrotic parietal cells. Conclusions: H. suis induces necrosis of parietal cells. We previously found a similar phenomenon with Helicobacter felis. This has prompted ongoing in-vitro studies of necrosis-inducing virulence factors.
5 A COMPARISON OF STUDENT LEARNING USING MICROSCOPES AND GLASS SLIDES OR DIGITIZED IMAGES P.J. Brown *, D. Fews y and N.J. Belly *University of Nottingham, School of Veterinary Medicine and Science and y University of Bristol School of Clinical Veterinary Science, UK Introduction: Histopathology has traditionally been taught using microscopes and histology slides, but the use of computers to view digitized images is becoming more common. The student experience of using both methods was assessed both objectively and subjectively. Materials and Methods: Students, at either Bristol, where histopathology has traditionally been taught using glass slides, or at Nottingham, that makes use of digitized images (Digital Slidebox [ÓSlidepath, Dublin]) completed a simple formative test before and after taking part in a practical class using either microscopes and histology slides or digitized images of the same slides. Results: In general, the performance of the students in the tests improved after participation in the practical classes; there was little difference between students using glass slides or Digital Slidebox. Use of Digital Slidebox improved performance in questions that required more depth of knowledge beyond simple recognition of tissues or histopathological changes; use of microscopes improved performance in some questions relating to tissue recognition. A subjective assessment showed no consistent student preference for digitized images or microscopes; the importance of the teacher/instructor during practical classes was emphasized. Conclusions: Digitized images are useful in teaching veterinary histopathology, but they are not more effective than teaching using microscopes and histology slides.
ESVP/ECVP Proceedings 2009
141:4, 2009
3
4
COMPARISON OF THE PATHOLOGY OBSERVED IN LAMBS AND ADULT SHEEP EXPERIMENTALLY INFECTED WITH MYCOBACTERIUM AVIUM SUBSP. PARATUBERCULOSIS L. Delgado, M. Mun˜oz, C. Garcı´a-Pariente, M. Fuertes, J. Benavides, J. Gonza´lez, M. Ferreras, V. Pe´rez and J.F. Garcı´a Marı´n IGM-CSIC-ULE, Department of Animal Health, University of Leo´n, Spain Introduction: The objective of this study was to evaluate the susceptibility of adult sheep to Mycobacterium avium subsp. paratuberculosis (Map) infection using different doses of Map. Materials and Methods: 24 lambs and 22 adult sheep were orally infected with two doses of Map (1010 and 103 CFU). Fourteen animals remained as uninfected controls. The animals were necropsied at 120 and 210 days post-infection. Numbers of granulomas were counted and the severity of lesions was evaluated in samples of intestine and associated lymphoid tissue. Peripheral cellular immune response was assessed fortnightly. Results: No gross lesions were observed in any of the animals. Microscopical lesions of paratuberculosis were detected only in the high dose-infected groups. Adult sheep showed small, demarcated focal granulomas restricted to areas of lymphoid tissue. Lesions were larger, more numerous and extended to the lamina propria in the lambs. The peripheral IFN-g response appeared earlier in the adult sheep than in the lambs. Conclusions: These results indicate the possibility of infection and development of characteristic lesions of paratuberculosis in adult sheep. Adult sheep seem better able to control the progression of the disease than lambs.
PATHOGENESIS OF CHRONIC GASTRITIS IN AN ANIMAL MODEL OF HELICOBACTER INFECTION B. Flahou, S. Kumar, K. Van Deun, M. Vermoote, K. Chiers, F. Pasmans, F. Haesebrouck and R. Ducatelle Faculty of Veterinary Medicine, Ghent University, Belgium Introduction: The role of Helicobacter spp. other than H. pylori in the development of gastric pathology in domestic animals is unclear. Recently, we isolated and characterized Helicobacter suis from the gastric mucosa of pigs. Materials and Methods: Mongolian gerbils were experimentally infected with the newly described species H. suis. The development of gastric pathology was studied microscopically at different time intervals after infection. Results: From 3 weeks after infection onwards, bacterial colonization of the antrum was associated with gradually increasing infiltrations of T and B lymphocytes in the propria mucosae, extending into the submucosa and the tunica muscularis at later stages. The germinal centres of the lymphoid follicle-like structures were expanded. Simultaneously, there was a mild loss of parietal cells at the transition zone between fundus and antrum and an expansion of the dividing epithelial cell population. Ultrastructurally, the helically shaped bacteria were found in close association with parietal cells and in debris of necrotic parietal cells. Conclusions: H. suis induces necrosis of parietal cells. We previously found a similar phenomenon with Helicobacter felis. This has prompted ongoing in-vitro studies of necrosis-inducing virulence factors.
5 A COMPARISON OF STUDENT LEARNING USING MICROSCOPES AND GLASS SLIDES OR DIGITIZED IMAGES P.J. Brown *, D. Fews y and N.J. Belly *University of Nottingham, School of Veterinary Medicine and Science and y University of Bristol School of Clinical Veterinary Science, UK Introduction: Histopathology has traditionally been taught using microscopes and histology slides, but the use of computers to view digitized images is becoming more common. The student experience of using both methods was assessed both objectively and subjectively. Materials and Methods: Students, at either Bristol, where histopathology has traditionally been taught using glass slides, or at Nottingham, that makes use of digitized images (Digital Slidebox [ÓSlidepath, Dublin]) completed a simple formative test before and after taking part in a practical class using either microscopes and histology slides or digitized images of the same slides. Results: In general, the performance of the students in the tests improved after participation in the practical classes; there was little difference between students using glass slides or Digital Slidebox. Use of Digital Slidebox improved performance in questions that required more depth of knowledge beyond simple recognition of tissues or histopathological changes; use of microscopes improved performance in some questions relating to tissue recognition. A subjective assessment showed no consistent student preference for digitized images or microscopes; the importance of the teacher/instructor during practical classes was emphasized. Conclusions: Digitized images are useful in teaching veterinary histopathology, but they are not more effective than teaching using microscopes and histology slides.