Elektronenmikroskopische Untersuchungen an Schleimhautexstirpaten von Kaninchen nach in vitro‐Kontakt mit Pasteurella multocida subsp. multocida‐Stämmen

Abstract

Summary Electron microscopic investigations of mucosal exstirpates after in vitro contact with Pasteurella multocida subsp. multocida strains In vitro experiments of adhesion and colonisation of mucosal surface fragments (nose, trachea) from freshly killed rabbits with four strains of Pasteurella multocida subsp. multocida with different types of capsule antigen (A, D, without capsule) showed the following results: Above all the capsule serovar A strain, producing a capsule of hyaluronic acid and fimbria, were able to adhere and to form microcolonies on the mucosal surface. Microvilli of epithelial cells and mucus producing cells were recognized as the place of adhesion. The formation of microcolonies occurred with a destruction of the kinocilia, which was caused by a bacteriafree culture filtrate as well. Zusammenfassung In vitro‐Adhärenz‐ und Kolonisationsversuche mit 4 Pasteurella multocida subsp. multocida‐Stämmen verschiedener Kapseltypen (A, D, kapsellos) an Schleimhautexstirpaten (Nase, Trachea) frisch getöteter Kaninchen führten zu folgenden Resultaten: Vor allem der eine Hyaluronsäure‐Kapsel ausbildende Stamm des Kapseltyps A, bei dem Fimbrien nachzuweisen sind, ließ eine eindeutige Fähigkeit zur Anheftung und zur Ausbildung von Mikrokolonien erkennen. Als Ort der Anheftung waren Mikrovilli und schleimproduzierende Zellen zu erkennen. Die Mikrokoloniebildung ging mit einer Zerstörung der Kinocilien einher, die auch durch bakterienfreies Kulturfiltrat hervorgerufen wurde.

In vitro Binding of Pasteurella multocida Cell Wall Preparations to Tracheal Mucus of Cattle and Swine and to a Tracheal Epithel Cell Wall Preparation of Cattle

“…The mechanisms of attachment of P. multocida to mucosal surfaces of the respiratory tract has not been clarified. Some authors (1,6,8,14) have demonstrated an adhesion of P. multocida capsule Serovar A strains to epithelial cells of the respiratory tract (rabbit pharyngeal cells [6], porcine tracheal epithelial cells [8], nasal epithelial cells of calves [8], B~T C H E K , LUBKE and HELLMANN rabbit tracheal mucosa [ 11) and to tissue culture cell lines (HeLa-cells [6], primary kidney cells from calf and swine [14], and Vero cells [I, 61). Capsule Serovar D-strains did not ( 5 ) , or only at a low degree, attach to swine nasal epithelial cells (15).…”

“…Little is known regarding the attachment of bacteria to mucosal surfaces of the respiratory tract. Strains of P. multocida, possessing the capsular antigen A, were shown to bind to mucosal cells of different species and cell cultures, whereas capsular antigen D strains hardly showed any adhesion (1,5,6,8,14,15). Nacetylglucosamine reduced the binding of capsular antigen A strains to rabbit pharyngeal cells (6).…”