一株雷氏普罗维登斯菌的分离鉴定、生物学特性及其基因组学研究

ISOLATION,IDENTIFICATION,BIOLOGICAL CHARACTERISTICS,AND WHOLE-GENOME SEQUENCING OF A PROVIDENCIA RETTGERI STRAIN

为确定2020年6月浙江杭州一发病黄缘闭壳龟的病原体及病原特征,研究从患病龟肝脏中分离到一株优势菌HZ202006,对该菌进行形态学观察、16S rRNA序列分析、全基因组测序、人工感染实验及药敏试验。结果确认该菌株为雷氏普罗维登斯菌(Providencia rettgeri),短杆状,革兰氏阴性菌。全基因组测序显示该菌株完整基因组序列是由一条4.8 Mb的双链DNA和2个质粒组成。利用耐药基因数据库(CARD)和毒力因子数据库(VFDB)对测序基因进行注释,发现该菌有20个耐药基因和4个毒力因子。药敏试验结果显示,HZ202006只对阿米卡星表现为中度敏感,对青霉素类、头孢类、氨基糖苷类等16种常见的抗生素耐药。研究分离并鉴定了一株使黄缘闭壳龟患病的雷氏普罗维登斯菌,为水产养殖动物防控该菌引起的相关疾病提供参考。

In order to identify the pathogen and its characteristics in diseased Cuora flavomarginata in Hangzhou,Zhejiang,in June 2020,a dominant strain HZ202006 was isolated from the liver of the diseased turtles.Morphological observations,16S rRNA sequence analysis,whole-genome sequencing,artificial infection experiments,and antimicrobial sensitivity test were performed on this strain.The results confirmed that the strain is Providencia rettgeri,a short rod-shaped,Gram-negative bacterium.Whole-genome sequencing revealed that the complete genome sequence of this strain consists of a 4.8 Mbp double-stranded DNA and two plasmids.Annotation of the sequenced genes using the Comprehensive Antibiotic Resistance Database(CARD)and the Virulence Factors Database(VFDB)identified 20 resistance genes and four virulence factors in the bacterium.Antimicrobial sensitivity test demonstrated that HZ202006 was moderately sensitive only to amikacin,and resistant to 16 common antibiotics,including penicillin,cephalosporins,and aminoglycosides.This study isolated and identified a strain of P.rettgeri causing disease in C.flavomarginata,providing insights for disease control in aquaculture animals affected by this bacterium.