对从江苏省某鸽场病死鸽脏器中分离的细菌进行分离鉴定.通过细菌培养、革兰染色镜检及生化特性测定等对分离株进行初步鉴定；扩增分离株的16S rDNA片段并测序,Blast搜索比对确定细菌的种属；通过动物致病性试验和药敏试验来检测分离株的致病力及耐药性.结果:3株细菌的16S rDNA序列测定和Blast分析表明与奇异变形杆菌参考株的同源性达99.4％ ～99.8％,确定为奇异变形杆菌；致病性试验显示奇异变形杆菌对鸽子和小鼠均有致病力；药敏试验表明奇异变形杆菌对头孢菌素类抗生素和氟苯尼考敏感,对青霉素类和磺胺类抗生素等有耐药性.结果表明,从鸽子脏器中所分离的细菌为奇异变形杆菌,具有较强的致病力和多重耐药性.

OBJECTIVE:To investigate the role of ompR gene from Salmonella enteritidis in biofilm formation and virulence.METHODS:We constructed an ompR mutant of Salmonella enteritidis by suicide plasmid pGMB151. Biofilm forming ability of the mutant was detected by crystal violet assay and scanning electron micrography. Virulence of the mutant was determined by assay of adherence to and invasion of epithelial cells, and mouse challenge experiments.RESULTS:The ompR mutant was confirmed by RT-PCR and the pattern of outer membrane protein. The mutant did not produce cellulose, curli, and biofilm, and showed similar adherence percentage to and invasion percentage of epithelial cells as wild type strain. In addition, intraperitoneal challenge of bacteria in BALB/c mice revealed that LD50 of the mutant strain was 10(6.67) CFU, while that of the wild type strain was less than 2 CFU.CONCLUSION:These data indicate that the ompR gene is involved in both biofilm formation and virulence in Salmonella enteritidis.

鸡白痢沙门菌在世界范围内引起养殖业的严重经济损失,虽然其病原体血清型一致,但不同菌株的生物学特性存在很大差异.沙门菌可形成生物膜,而处于生物膜状态的细菌可增强对外界的抵抗力,造成持续感染和重复感染 [1].因此,有必要在鸡白痢沙门菌分离鉴定的同时进行生物膜形成能力研究.我们从1例疑似鸡白痢的病鸡中分离出1株鸡白痢沙门菌,测定其生物膜形成能力,为进一步了解鸡白痢沙门菌生物膜的作用奠定了基础.