TDK conference 2015

Actinobacillus pleuropneumoniae, the causative agent of haemorrhagic necrotic pneumonia and fibrinous pleuritis of swine, can occur worldwide, including Hungary. Antibiotic susceptibility of 20 A. pleuropneumoniae strains isolated from pathologic cases in Hungary between 2012 and 2015 was examined in the disk diffusion and broth microdilution method with 10 antibiotics used in the practice. The strains showed susceptibility to a wide range of antibiotics.

In the disk diffusion test all of strains proved to be susceptible to tiamulin, the majority of the strains were susceptible to florfenicol, ampicillin, ceftiofur and tilmicosin, some strains were moderately susceptible to spektinomycin, gentamycin, enrofloxacin and to penicillin. Several strains showed resistance against gentamycin, oxitetracyclin and spectinomycin.

The antibiotics had wide ranges of minimum inhibitory concentrations. All 20 strains showed susceptibility to tilmicosin, 19 (95%) strains to tiamulin and florfenicol, 18 (90%) strains to enrofloxacin and 17 (85%) strains to ampicillin. Ten (50%) strains were moderately susceptible to spectinomycin and 8 (40%) strains to gentamycin. High percentage of the strains showed resistance against oxatetracyclin and spectinomycin (40-40%) and 35% were resistant to gentamycin.

Examination of the antibiotic susceptibility of A. pleuropneumoniae with the two methods shoved difference, and the disc diffusion method proved to be less sensitive, so the results of the disk diffusion test have to be interpreted carefully.