The frequency of Haemophilus parasuis serovars in Brazil

摘要

The polyserositis and anthiritis caused by Haemophilus parasuis (HPS) present a syndrome known as Glasser's disease. It is an infectious and contagious disease with primary lesions characterised as arthritis, peritonitis, pleuritis, fibrinous pericarditis and meningitis. The importance of H. parasuis was recognized after the classification of seven serovars 1 to 7. Later, seven new ones were found and designated Jena 6 to Jena 12. The analysis of 243 HPS isolated from USA, Canada, Australia and Brazil revealed the presence of 5 new serovars, ND1 to ND5, and also the prevalence of 4,5, 13 and 14 serovars. Based on the comparison of the described and identified HPS serovars a classification of 1 to 15 serovars was proposed. It was observed that serovars 4 and 5 were prevalent in 290 samples isolated from 20 herds in West-Germany. Recently by testing 31 HPS samples isolated from Australia it was observed that serovars 5 and 13 were the mosl frequent followed by the non-serotyped samples. In Brazil,the disease was not known until an outbreak was reported in a farm with 15 sows. In this study, 17 samples of HPS were isolated and 10 were from animals with clinical signs and 5 samples were classified as belonging to 2, 4, 7 and 13 serovars and one asnon-serotyped. Recently 197 (22,1 percent) HPS isolators were made from 890 laboratory examinations that were positive for bacterial respiratory pathogens of swines. The role of HPS in swine pathology is not well defined, and the frequency of several serovars needs to be determined. The objective of the present work was the classification of the serovars of HPS isolations and determination of their frequencies in swine in Brazil.