Development of an ex vivo model to study adherence of Mannheimia haemolytica serovar 1 to mucosal tissues of the respiratory tract of cattle
| Autor: | Rebecca J. Morton, Jeremiah T. Saliki, Cyril R. Clarke, Jean M. Clarke, Robert W. Fulton |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
Male
Respiratory Mucosa Pathology medicine.medical_specialty Respiratory Tract Diseases Biology Bacterial Adhesion Microbiology Nasopharynx medicine Animals Pasteurellosis Pneumonic Respiratory system Mannheimia haemolytica Colony-forming unit General Veterinary General Medicine medicine.disease Mucus Epithelium Microscopy Electron medicine.anatomical_structure Microscopy Electron Scanning Cattle Pasteurellosis Ex vivo Respiratory tract |
| Zdroj: | American Journal of Veterinary Research. 62:805-811 |
| ISSN: | 0002-9645 |
| DOI: | 10.2460/ajvr.2001.62.805 |
| Popis: | Objective—To develop and validate an ex vivo model for study of adherence ofMannheimia haemolytica(formerlyPasteurella haemolytica) to respiratory tract mucosa of cattle and to use this model to confirm adherence ofM haemolyticaserovar 1 (Mh1) to several relevant respiratory mucosal surfaces.Sample Population—Excised nasal, nasopharyngeal, turbinate, and tonsillar mucosal tissue from the bovine upper respiratory tract.Procedure—Mh1 was radiolabeled by use of tritiated leucine. Various concentrations of labeled bacteria were incubated with bovine upper respiratory tract tissues for various times. Tissue was washed to remove nonadherent bacteria, and percentage of bacteria adhered (percentage of adherence) was estimated using radioactivity. Using an optimal inoculum concentration and incubation time, percentage of Mh1 adherence was compared on nasal, nasopharyngeal, turbinate, and tonsillar mucosal tissue, and adherence to nasopharyngeal tissue was confirmed by scanning and transmission electron microscopy.Results—The optimal Mh1 inoculum concentration was 1 × 107colony forming units/ml and incubation time was 3 hours. Percentage of adherence of Mh1 to nasopharyngeal tissue was greater than adherence to other tissue types.Conclusions and Clinical Relevance—The ex vivo model maintained the functional and structural integrity of bovine upper respiratory tract mucosa, as confirmed by light and electron microscopy. Electron microscopy revealed participation of epithelial cell cilia and surface mucus in adherence of Mh1 to nasopharyngeal tissue. Adherence of Mh1 was confirmed in repeated assays, indicating that this organism adheres to upper respiratory tract mucosa of cattle. (Am J Vet Res2001;62:805–811) |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|