%0 Journal Article
%T Ultrastructural Comparison of the Nasal Epithelia of Healthy and Naturally Affected Rabbits with Pasteurella multocida A
%A Paula Esquinas
%A Luc¨ªa Botero
%A Mar¨ªa del Pilar Pati£¿o
%A Carolina Gallego
%A Carlos Iregui
%J Veterinary Medicine International
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/321390
%X An ultrastructural comparison between the nasal cavities of healthy rabbits and those suffering from two forms of spontaneous infection with Pasteurella multocida was undertaken. Twelve commercially produced rabbits of different ages and respiratory health status were divided into four groups: healthy from 0 to 21 days (G1, ); healthy from 23 to 49 days (G2, ); healthy from 51 to 69 days (G3, ); diseased rabbits with septicemia and the rhinitic form of P. multocida infection (G4, ). The main ultrastructural changes observed were a widening of the interepithelial spaces, increased activity and number of goblet cells, the formation of two types of vacuoles in epithelial cells, the degranulation and migration of heterophils between the epithelial cells, and the association of this migration with some of the other changes. No bacteria were observed adhering to the epithelium, and very few were observed free in the mucus. Scant inter-epithelial spaces were found in healthy rabbits, but they were not as large and numerous as those found in diseased animals. We discuss the origin and meaning of these changes but, we focus on the significance of the inter-epithelial spaces and goblet cells for the defense of the upper respiratory airways against the bacterium and its lipopolysaccharide. 1. Introduction P. multocida is commonly associated with different entities of rabbits [1¨C7]. Clinical signs in rabbits may include rhinitis (snuffles) with purulent nasal discharge, septicemia, pneumonia, otitis media, pyometra, meningitis, and localized abscesses [7¨C9]. The nasal cavity is considered the natural habitat of P. multocida in different species, including the rabbit [10]; however, neither the normal ultrastructure of this region nor the pathologic changes during natural infection with P. multocida have been described in rabbits. Al-Haddawi et al. [11¨C13] described the gross, histological, and ultrastructural lesions in this anatomical region of rabbits subjected to different experimental infection protocols with P. multocida A3, P. multocida A3 plus hydrocortisone, and P. multocida serotype D1. The experimental animals were killed 14 and 21 days after inoculation. In general, the gross findings in all three studies were congestion of the nasal mucosa, hemorrhages, and/or mucopurulent exudates. Histologically, these authors observed mild to chronic catarrhal and suppurative rhinitis, with few rabbits displaying ulceration of the mucosal surface. Ultrastructurally, they found severely degenerated epithelial cells that were swollen and had vacuolated cytoplasm; these
%U http://www.hindawi.com/journals/vmi/2013/321390/