4株鹅源鸭疫里默氏杆菌生物学特性分析

BIOLOGICAL CHARACTERISTICS OF FOUR RIEMERELLA ANATIPESTIFER ISOLATES FROM GEESE

近几年来鹅群发生鸭疫里默氏杆菌(Riemerella anatipestifer,RA)感染的病例有增多的现象,为了分析其原因,本研究对4株四川鹅源鸭疫里默氏杆菌分离株的生物学特性进行了解析。血清型鉴定的结果表明,4株中SC-11和SC-12株是血清型1型,SC-13和SC-17株未能确定血清型;溶血实验结果表明,4株鹅源鸭疫里默氏杆菌均能溶血,其中SC-13和SC-17株在血平板上的溶血能力较强;生物被膜检测结果表明,4株中SC-12和SC-13株形成生物被膜的能力较强,另2株形成生物被膜的能力较弱;药敏实验结果表明,这4株鹅源鸭疫里默氏杆菌对头孢类抗菌药物敏感,对多粘菌素和诺氟沙星耐药;值得注意的是,SC-11和SC-17株对卡那霉素敏感,推测这两株鹅源RA与本实验室过去分离的鸭源RA(卡那霉素耐受菌株)不是同一来源;对雏鸭的致病性实验结果表明,4株鹅源鸭疫里默氏杆菌对雏鸭均有致病性。本研究结果为进一步分析鹅源和鸭源鸭疫里默氏杆菌的生物学特性异同奠定了基础。

Riemerella anatipestifer infection cases in goose flocks has increased in recent years.In order to investigate the causes,four R.anatipestifer strains isolated from sick geese in Sichuan province were analyzed in the present study.The results of slide agglutination test showed that SC-11 and SC-12 isolates belonged to serotype 1 and the serotypes of isolates SC-13 and SC-17 were not be determined.Hemolytic activity test showed that all the four R.anatipestifer isolates hemolyzed duck red blood cells on the duck blood agar,and isolates SC-13 and SC-17 had stronger hemolysis ability than that of SC-11 and SC-12.In addition,the capacity of these four R.anatipestifer isolates to form biofilms was examined by a crystal violet staining assay.The results showed that the isolates SC-12 and SC-13 had stronger ability to form biofilm,while that of the other 2 isolates was weak.The drug sensitivity test showed that these four isolates were susceptible to cephalosporins but resistant to polymyxins and norfloxacin.It was noteworthy that the isolates SC-11 and SC-17 were susceptible to kanamycin,suggesting that these two isolates were not the same as the kanamycin resistant duck isolates from our laboratory in the past 20 years.In addition,all four isolates from geese were pathogenic to ducklings.This study would be helpful to determine whether there were differences in biological characteristics between goose-derived and duck-derived RA isolates.