一株致多器官功能衰竭非O1/O139群霍乱弧菌的鉴定

Identification of non-O1/non-O139 Vibrio cholerae causing multiple organ dysfunction syndrome

目的对1例不洁饮食致多器官衰竭患者血液中霍乱弧菌进行鉴定。方法取患者静脉血进行细菌的分离培养,观察细菌的形态特征,并进行生化试验、质谱鉴定、血清学检测、16SrRNA分析、毒力基因检测。结果分离菌初步鉴定为非O1/O139群霍乱弧菌。MALDI-TOF MS鉴定该菌为霍乱弧菌,置信度99.9%。16SrRNA扩增产物测序后经blast分析,与数据库中霍乱弧菌相似性为99%。该菌无毒力基因ctx、Tcp,毒力基因lolB、toxR、rtxC、hlyA、Hap、PrtV、ompU均阳性。结论该致病菌为非O1/O139群霍乱弧菌,患者发生急骤性多器官功能衰竭死亡可能与该菌携带lolB、toxR、rtxC、hlyA、Hap、PrtV、ompU等毒力基因密切相关。

Objectives To identify a strain of Vibrio cholerae from the blood of a patient with multiple organ dysfunction syndrome caused by unclean food and water. Methods A strain was isolated from the venous blood of a patient and cultured,and its morphological characteristics were observed.The strain was subjected to biochemical testing,its characteristics were determined using matrix-assisted laser desorption/ionization mass spectrometry,serology was performed,and the 16 SrRNA sequences and virulence genes of the isolate were analyzed. Results This clinical isolate was confirmed to be non-O1/non-O139 V.cholerae.MALDI-TOF MS identified this strain as V.cholerae with a reliability of99.9%.16 SrRNA was amplified,and sequencing blast analysis indicated that the strain had 99% similarity to strains in the NCBI database.The virulence genes lolB,toxR,rtxC,hlyA,Hap,PrtV,and ompU were found in the strain while the virulence genes ctx and Tcp were not. Conclusion The pathogen was identified as non-O1/non-O139 V.cholerae,and the development of multiple organ dysfunction syndrome and death may be associated with virulence genes such as lolB,toxR,rtxC,hlyA,Hap,PrtV,and ompU.