The swine pleuropneumonia is a major respiratory disease that causes great economic losses in pig farming. The Actinobacillus pleuropneumoniae (APP) is the etiologic agent of this disease and are classified into 15 serotypes. These secrete different combinations of exotoxins ApxI, ApxII, APX and ApxIV III have been used in the differentiation of serotypes by multiplex PCR (mPCR). The reported technique does not allow the differentiation of serotypes 2, 8 and 15 (exhibit same pattern of amplification) as well as serotypes 12 and 13. In order to improve the discriminatory capacity of this procedure, this paper describes the combination of a second mPCR based on amplification of genes of capsular antigens. The combined test was tested with reference strains belonging to 15 serotypes and also 10 field isolates. The proposed technique was capable of differentiating all 15 serotypes tested (reference strains), and was able to identify field isolates from clinical cases, demonstrating that the molecular technique is a quick and efficient identification of this important pathogen that affects the swine production. The proposed technique assisted in differentiating the 15 serotypes tested (reference strains), but also provided identification of field isolates from clinical cases, demonstrating that the molecular technique is a quick and efficient identification of this important pathogen that affects pig farming, even taking into account the limitations of the technique.
APP; swine; molecular differentiation; exotoxins; pleuropneumonia
