| prevalence of actinobacillus pleuropneumoniae, actinobacillus suis, haemophilus parasuis, pasteurella multocida, and streptococcus suis in representative ontario swine herds. | tonsillar and nasal swabs were collected from weanling pigs in 50 representative ontario swine herds and tested for the presence of 5 important bacterial upper respiratory tract pathogens. all but 1 herd (2%) tested positive for streptococcus suis by polymerase chain reaction (pcr); 48% of herds were s. suis serovar 2, 1/2 positive. in all but 2 herds there was evidence of haemophilus parasuis infection. in contrast, toxigenic strains of pasteurella multocida were detected by a p. multocida--enz ... | 2008 | 18505187 |