Résumé
Haemophilus parasuis infection, known as Glãsser's disease, is characterized by fibrinous polyserositis, arthritis and meningitis in piglets. Although traditional diagnosis is based on herd history, clinical signs, bacterial isolation and serotyping, the molecular-based methods are alternatives for species-specific tests and epidemiologic study. The aim of this study was to characterize H. parasuis strains isolated from different states of Brazil by serotyping, PCR and ERIC-PCR. Serotyping revealed serovar 4 as the most prevalent (24 percent), followed by serovars 14 (14 percent), 5 (12 percent), 13 (8 percent) and 2 (2 percent), whereas 40 percent of the strains were considered as non-typeable. From 50 strains tested 43 (86 percent) were positive to Group 1 vtaA gene that have been related to virulent strains of H.parasuis. ERIC-PCR was able to type isolates tested among 23 different patterns, including non-typeable strains. ERIC-PCR patterns were very heterogeneous and presented high similarity between strains of the same animal or farm origin. The results indicated ERIC-PCR as a valuable tool for typing H. parasuis isolates collected in Brazil.
Sujets)
Animaux , Infections à Haemophilus , Haemophilus parasuis/isolement et purification , Haemophilus parasuis/pathogénicité , Techniques in vitro , Réaction de polymérisation en chaîne , Analyse de séquence d'ADN , Tests sérologiques , Génotype , Méthodes , Suidae , Méthodes , VirulenceRésumé
A distribuição dos genes de virulência sefC, pefA e spvC foi investigada em 110 amostras de Salmonella Enteritidis pertencentes ao fagotipo 4 através da reação em cadeia da polimerase. A influência destes genes na colonização do ceco e invasão do fígado e baço em pintinhos de um dia de idade foi avaliada. Oito amostras foram negativas para o gene spvC, três para o gene pefA e uma amostra para o gene sefC. Estes resultados permitiram a classificação das amostras em quatro genótipos. A presença destes genes não influenciou a invasão da bactéria no fígado e baço das aves dez dias após a infecção, entretanto, a presença de mais de um gene fimbrial pode ter relação com a colonização cecal.