Characterization of a Novel Conjugative Plasmid in Edwardsiella piscicida Strain MS-18-199
Characterization of a Novel Conjugative Plasmid in Edwardsiella piscicida Strain MS-18-199
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DOI：
10.3389/fcimb.2019.00404
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发表时间：
2019-11-27
影响因子：
5.7
通讯作者：
Lawrence, Mark L.
中科院分区：
文献类型：
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作者：
Abdelhamed, Hossam;Ramachandran, Reshma;Lawrence, Mark L.
鱼爱德华氏菌是一种重要的野生和养殖鱼类损失的病原菌。从来自密西西比州东部的一条患病杂交鱼中分离到的鱼腥藻MS-18-199菌株对氟苯尼考、氯霉素、土霉素、多西环素、红霉素、四环素、阿奇霉素、壮观霉素、磺胺和杆菌素表现出抗性。为了探讨鱼腥藻MS-18-199的抗性机制，提取基因组DNA，采用长(牛津纳米孔)和短(Illumina)相结合的方法进行全基因组测序。菌株MS-18-199的基因组中含有一个新的质粒，命名为pEPMS-18199。该基因含多个抗菌素耐药(AMR)元件/基因，包括氟苯尼考外排泵(Flor)、四环素外排泵(TetA)、四环素抑制蛋白(TetR)、磺胺抗性(Sul2)、氨基糖苷类O-磷酸转移酶aph(6)-ID(STRb)和氨基糖苷类O-磷酸转移酶aph(3)-Ib(StrA)。在pEPMS-18199中还发现了两个编码与砷转运/抗性相关的蛋白质组分的基因arsa和arsd。此外，pEPMS-18199还携带12个接合转移基因(TrA)、8个转座酶和插入元件、2个质粒稳定蛋白、2个复制蛋白和3个分配蛋白(PAR系统)。动员和稳定性实验结果表明，pEPMS-18199在宿主细胞中高度稳定，可以通过接合的方式转移到大肠杆菌和爱德华氏菌中。据我们所知，这是在美国首次在鱼腥藻中检测到多药耐药(MDR)结合质粒。在水产养殖系统中仔细跟踪该质粒是有必要的。了解AMR在水产养殖中的分子机制对于抗菌管理很重要。
Edwardsiella piscicida is a pathogenic bacterium responsible for significant losses in important wild and cultured fish species. E. piscicida strain MS-18-199 recovered from a diseased hybrid catfish from East Mississippi and showed resistance to florfenicol, chloramphenicol, oxytetracycline, doxycycline, erythromycin, tetracycline, azitromycin, spectinomycin, sulfonamide, and bacitracin. To explore the mechanisms of resistance in E. piscicida strain MS-18-199, genomic DNA was extracted and subjected to whole genome sequencing (WGS) using a combination of long (Oxford Nanopore) and short (Illumina) reads. The genome of strain MS-18-199 revealed a novel plasmid named pEPMS-18199. The 117,448 bp plasmid contains several antimicrobial resistance (AMR) elements/genes, including florfenicol efflux pump (floR), tetracycline efflux pump (tetA), tetracycline repressor protein (tetR), sulfonamide resistance (sul2), aminoglycoside O-phosphotransferase aph(6)-Id (strB), and aminoglycoside O-phosphotransferase aph(3)-Ib (strA). Two genes, arsA and arsD, that encode protein components related to transport/resistance to arsenic were also found in pEPMS-18199. In addition, pEPMS-18199 carried twelve conjugative transfer genes (tra), eight transposases and insertion elements, two plasmid stability proteins, two replication proteins, and three partitioning proteins (par system). Results from mobilization and stability experiments revealed that pEPMS-18199 is highly stable in the host cell and could be transferred to Escherichia coli and Edwardsiella ictaluri by conjugation. To our knowledge, this is the first detection of a multidrug resistance (MDR) conjugative plasmid in E. piscicida in the United States. Careful tracking of this plasmid in the aquaculture system is warranted. Knowledge regarding the molecular mechanisms of AMR in aquaculture is important for antimicrobial stewardship.