Vena M M, Blanchard B, Thomas D, Kobisch M
Centre National d'Etudes Vétérinaire et Alimentaires, Laboratoire Central de Recherches Avicoles et Porcines, Ploufragan, France.
Ann Rech Vet. 1991;22(2):211-8.
Pasteurella multocida can often be isolated from pneumonic lungs in pigs. There is little information about the pathogenesis of this infection. Attachment of microorganisms to eucaryotic cells is considered to be a prerequisite for colonization of the host in the pathogenesis of bacterial infections. Forty-seven P multocida strains isolated from pigs in France, and belonging to capsular type A or D were tested for their ability to agglutinate human erythrocytes, and to adhere to tracheal and lung cells. Each isolate was tested for dermonecrotic toxin production. Adherent strains were further observed by electron microscopy to look for attachment structure. Only type A strains agglutinated human O erythrocytes, but no relationship was observed between hemagglutination and dermonecrotic toxin production. The results of the adherence tests showed a greater affinity (P less than 0.05) of type A strains for lung cells (50% were adherent, whereas only 20% of type D strains were adherent) but did not reveal any correlation between adherence and the presence of dermonecrotic toxin. Microscope observations showed that these P multocida strains did not possess any pili-like structures. In conclusion, by means of the adherence test we were able to demonstrate a stronger adherence of type A strains and this adherence did not seem to be related to pili-like structures.
多杀性巴氏杆菌常可从患肺炎的猪肺中分离得到。关于这种感染的发病机制，目前所知甚少。在细菌感染的发病过程中，微生物附着于真核细胞被认为是其在宿主体内定植的一个先决条件。对从法国猪群中分离得到的47株多杀性巴氏杆菌菌株（属于A或D荚膜型）进行了检测，以评估它们凝集人红细胞以及黏附气管和肺细胞的能力。对每一株分离菌进行了皮肤坏死毒素产生情况的检测。对黏附菌株进一步通过电子显微镜观察，以寻找附着结构。只有A 型菌株能凝集人O型红细胞，但未观察到血凝作用与皮肤坏死毒素产生之间存在关联。黏附试验结果显示，A 型菌株对肺细胞具有更高的亲和力（P<0.05）（50%的菌株黏附，而D型菌株只有20%黏附），但未揭示黏附与皮肤坏死毒素的存在之间有任何相关性。显微镜观察表明，这些多杀性巴氏杆菌菌株不具有任何菌毛样结构。总之，通过黏附试验，我们能够证明A 型菌株的黏附性更强，且这种黏附似乎与菌毛样结构无关。
