Veterinary session

Actinobacillus pleuropneumoniae is a Gram-negative, facultative anaerobic, fastidious bacterium which causes respiratory disease in swine throughout the world. Haemorrhagic-necrotic pneumonia and fibrinous pleuritis can be seen in growing pigs. The bacterium is facultative pathogenic, it is present on the mucous membrane of the respiratory tract of swine and can cause disease in case of different predisposing factors.

On the basis of NAD requirement for growth A. pleuropneumoniae biotype 1 (NAD-dependent) and biotype 2 (NAD-independent) can be distinguished. After combining the previous typing systems 15 serotypes can be differentiated.

The aim of the study was to collect data on the frequency of the different serotypes and their antibiotic susceptibility

Thirty pneumonic samples were collected in two slaughterhouses representing ten counties. Primary and secondary cultural, morphological and biochemical features of the bacterial isolates were tested. According to the cultural and biochemical characteristics twenty biotype 1 (NAD-dependent) A. pleuropneumoniae strains were identified.

The isolated strains were serotyped on the basis of surface antigens with indirect haemagglutination test. As a result of serotyping 12 strains proved to be of serotype 2, 2-2 strains were serotypes 8 and 9, 1 strain was serotype 12 and 3 strains could not be serotyped by hyperimmun sera.

Antibiotic susceptibility of the isolated A. pleuropneumoniae strains were tested using the disc diffusion method and broth dilution method (MIC). The most widely used antibiotics were chosen for the examination with the following results:

The strains were susceptible to penicillin-G, ceftiofur, enrofloxacin and tiamulin, but resistante for oxytetracycline.