Serotype distribution of Actinobacillus pleuropneumoniae isolated from porcine pleuropneumonia in the Czech Republicduring period 2003-2004

A total of 245 isolates of Actinobacillus pleuropneumoniae included in this study were isolated from lung tissues of pigs which died of porcine pleuropneumonia. The isolates were obtained from 52 swine herds in the Czech Republic over the period 2003-2004. All the serotypes were serotyped by the coagglutination test. All isolates with cross-reactivity between serotypes 9 and 11 or 1, 9, and 11 in the coagglutination test were further serotyped by the quantitative coagglutination test. The results of serotyping showed that serotype 9 was dominant (46.5%) followed by serotypes 2 (18.5%), and 11 (14.2%). Two-way cross-reaction between serotypes 9 and 11 was found for 7.5% of the isolates. The serotypes 4, 5, 7, and 12 were found infrequently (2.4%). The isolates that could not be serotyped (11%) were classified by PCR typing system based on the apx and omlA genes into the serotype groups 1, 9, 11 (7.5%); 2, 8 (2.3%), and 7, 13 (1.1%).