Systemic Subcutaneous Panniculitis Associated with Actinobacillus Pleuropneumoniae Serotype 2 Infection in a Pig during Meat Inspection

Abstract

During meat inspection, a six-month-old pig had systemic multifocal, coalescing suppurative panniculitis in subcutaneous adipose tissues. Actinobacillus pleuropneumoniae was isolated from the subcutaneous lesions and identified as A. pleuropneumoniae serotype 2 by Multiplex PCR assay. Histologically, there were multifocal panniculitis consisting of various degrees of neutrophil and macrophage infiltrations. A large number of Gram-negative bacilli were visible in the center. Occasional Splendore-Hoeppli phenomenon was also observed. Immunohistochemically, the organisms in the lesions showed a positive reaction to antibodies against A. pleuropneumoniae serotype 2. These results indicate that the present subcutaneous suppurative panniculitis was closely associated with A. pleuropneumoniae serotype 2 infection.