Virulence Genes and Antimicrobial Resistance Profiles ofPasteurella multocidaStrains Isolated from Rabbits in Brazil

Abstract

Pasteurella multocidais responsible for a wide range of diseases in domestic animals. In rabbits, the agent is related to nasal discharge, pneumonia, otitis media, pyometra, orchitis, abscess, and septicemia. One hundred and forty rabbits with respiratory diseases from four rabbitries in São Paulo State, Brazil were evaluated for the detection ofP. multocidain their nasal cavities. A total of twenty-nine animals were positive toP. multocidaisolation, and 46 strains were selected and characterized by means of biochemical tests and PCR.P. multocidastrains were tested for capsular type, virulence genes, and resistance profile. A total of 45.6% (21/46) of isolates belonged to capsular type A, and 54.34% (25/46) of the isolates were untypeable. None of the strains harbouredtoxAorpfhAgenes. The frequency of the other twenty genes tested was variable, and the data generated was used to build a dendrogram, showing the relatedness of strains, which were clustered according to origin. Resistance revealed to be more common against sulfonamides and cotrimoxazole, followed by erythromycin, penicillin, and amoxicillin.