1株鸽源鸡杆菌复合群3的分离和鉴定

Isolation and identification of one pigeon-origin Gallibacterium genomo sp.3

报道我国鸽场中鸡杆菌的感染情况.四川某种鸽场的种鸽出现以消瘦、呼吸困难、气管和肺出血、腹膜炎、输卵管炎等为主要特征的疾病.选取代表性病例,进行细菌分离和病毒检测,并对分离菌进行形态学观察、生化鉴定、动物试验、药敏试验和16S rRNA 基因序列分析.结果显示,部分病鸽只检测到新城疫病毒；从肝、肺中分离到1株革兰阴性短杆菌,命名为 SC01,该菌株为致病菌,小鼠半数致死量（LD50）为1.26＆#215;109 CFU/mL,能发酵多数糖和醇类,对头孢类药物较敏感.将 SC01与 GenBank 中同源性较近的15株细菌的16S rRNA 基因序列进行同源性分析,发现 SC01株与4株鸡杆菌复合群3（Gallibacterium genomo sp.3）的同源性为98.5%~99.5%,其中与EU423996的同源性最高,为99.5%,证实该菌株为鸡杆菌复合群3.试验结果为鸡杆菌复合群3感染的流行病学调查、诊断与治疗提供了新的参考.

Summary Gallibacterium infection was a new infectious disease observed in some areas of China,which was mainly harmful for laying hen,resulting in salpingitis,oophoritis,peritonitis,septicemia,hepatitis,enteritis, respiratory tract diseases,and so on.So far,most of the G.anatis were isolated from poultry,including chickens, ducks,pigeons,geese,parrots,quail and guinea fowl,etc.Isolation of Gallibacterium from pigeons was not reported in China. A contagious disease occurred in one breeding farm of pigeon in Sichuan Province in January of 2013,with the characteristic signs of depressed wasting,dyspnea,diarrhea,and so on.The morbidity was about 43%,and the mortality was about 18%.The disease was mainly found in female pigeons,and female pigeons of different ages could be infected,especially pigeons of 1 to 1.5 years old.Mild bleeding and mucus could be observed in diseased pigeons,and other gross lesions could also be observed including hemorrhage of lung,peritonitis,salpingitis,mild＆amp;nbsp;bleeding of duodenum,and so on.This disease had caused great economic losses to the pigeon farm.In order to propose a proper treatment program for this disease,representative samples were collected from disease pigeons for bacteria isolation and virus detection. The bacteria were isolated by blood agar and were identified by following test：morphological observation, biochemical identification,animal experiment,antibiotic sensitive experiment,1 6S rRNA gene sequence analysis. Animal experiments were conducted by infecting mice and pigeons to observe its pathogenicity.For the virus detection,the nucleotide sequences of infectious bronchitis virus （IBV）,avian influenza virus subtype （H 9 N2） and Newcastle disease virus （NDV） were detected by RT-PCR. The results showed that NDV was detected from the lung and trachea of some sick pigeons,and one bacterial strain was isolated from the livers and lungs of sick pigeons and named as SC01.The SC01 strain was gram-negative （G-）,short rod-shaped bacteria.It was pathogenic to mice,and the median lethal dose to mice was 1.26 ＆#215; 10 9 CFU/mL.Biochemical test showed that it can ferment most sugars and alcohols.Sensitive drug screen revealed that the SC01 strain was sensitive to ceftriaxone sodium,cefoperazone sodium,florfenicol,cephalexin,cefazolin,and resistant to neomycin,streptomycin,erythromycin,sulfafurazole,etc.The 1 6S rRNA gene sequence of the SC01 strain was blasted in GenBank,and the results showed that the nucleotide sequence homologies of SC01 and Gallibacterium ,Pasteurella , Haemophilus ,Actinobacillus were relatively high. The 1 6S rRNA nucleotide sequence homologies of SC01 and four G.genomo sp.3 strains were 98.5% 99.5%,and the highest homology （99.5%） came from the comparison between the sequences of SC01 and EU423996.Phylogenetic analysis showed that SC01 strain and nine Gallibacterium strains formed an independent big branch in phylogenetic tree.The SC01 strain and G. genomo sp. 3 fell into the same small branch. Meanwhile, Pasteurella , Haemophilus and Actinobacillus formed another big branch in phylogenetic tree. 〈br〉 In conclusion, a G. genomo sp. 3 was isolated from diseased pigeons, and its biological character, pathogenicity,drug sensitivity and 1 6S rRNA sequence were also analyzed.The results provide an important reference for the epidemiological investigation,diagnosis and therapy of G.genomo sp.3 infection in China.In addition,the appearance of G.genomo sp.3 infection in pigeons may provide a new challenge for the prevention and therapy of pigeon disease in China.