Biochemical characteristics and serotypes of Actinobacillus pleuropneumoniae isolated from pneumonic lungs of pigs

돼지 폐렴병소에서 분리한 Actinobacillus pleuropneumoniae의 특성에 관한 연구

The present study was conducted to investigate the biochemical and serologic characteristic of Actinobacillus pleuropneumoniae isolated from pneumonic lungs of pigs during the period from January 1992 to April 1993. A pleuropneumoniae was isolated from 17(27.0%) of 63 growing pigs with respiratory signs and 21(6.4%) of 330 pneumonic lungs of slaughtered pigs. The seasonal isolation frequency of A pleuropneumoniae was higher in winter and spring than that in summer or fall. The biochemical and cultural properties of A pleluropneumoniae isolated from the pneumonic lungs of pigs were identical to those of the reference strains used. The isolates were highly susceptible to ampicillin, cephalothin, ceftiofur, ciprofloxacin(MIC : ${\leq}0.39{\mu}g/ml$) and moderately susceptible to amikacin, chloramphenicol, erythromycin, kanamycin, methicillin, penicillin-G, streptomycin(MIC : 0.78~25IU or ${\mu}g/ml$), respectively. Sulfadimethoxine, sulfamerazine, tylosine showed no response to the isolates(MIC : ${\geq}100{\mu}g/ml$). Among the 38 isolates, 21(55.3%) and 13(34.2%) were resistant to oxytetracycline aid lincomydn, respectively(MIC : ${\geq}50IU$ or ${\mu}g/ml$). The majority of 38 A pleuropneumoniae isolates were turned out as serotype 2(47.4%) or serotype 5(54.7%) and the remaining 3 isolates were evenly classified to serotype 7, 10 or 12. It was noted A pleuropneumonine serotype 5 isolates were more resistant to oxytetracycline than serotype 2 isolates.