Abstract

Pleuropneumonia caused by Actinobacillus pleuropneumoniae is one of the most devastating diseases in the scenario of swine global production, in which Brazil occupies a prominent place. A. pleuropneumoniae have been shown to be difficult to type by the existing methods given its existence in 15 different serotypes. The goals of this study were to establish an identification experimental strategy of A. pleuropneumoniae serotypes by multiplex PCR with apx genes and PCR-REA-apxIVA gene and evaluate the potential of ERIC, BOX and (GTG)₅-PCR as tools for molecular typing of A. pleuropneumoniaeisolates obtained from swine with clinical signs of pleuropneumonia in southeastern Brazil. Multiplex PCR and PCR-REA allowed the characterization of 95% of the isolates, with prevalence of band patterns equal to serotype reference strains 2, 7 and 8. Although, serotype 8 was not the most abundant, it was certainly the most widespread. The absence of predominant genotypes groups as observed by the rep fingerprinting and the emergence of different isolates throughout the years suggest molecular events that led to the great genetic variability observed. Our results display an effective strategy in the study of different serotypes of A. pleuropneumoniae and reveal an updated vision of the distribution and genomic fingerprinting of clinical isolates in southeastern Brazil.

Key words: Actinobacillus pleuropneumoniae, PCR-REA, ERIC-PCR, BOX-PCR, (GTG)₅-PCR.