Two types of genetic carriers, the IncP genomic island and the novel IncP-1β plasmid, for the aac(2′)-IIa gene that confers kasugamycin resistance in Acidovorax avenae subsp. Avenae
Two types of genetic carriers, the IncP genomic island and the novel IncP-1β plasmid, for the aac(2′)-IIa gene that confers kasugamycin resistance in Acidovorax avenae subsp. Avenae
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两种类型的遗传载体，IncP 基因组岛和新型 IncP-1β 质粒，用于赋予 Avenae 燕麦亚种春雷霉素抗性的 aac(2)-IIa 基因。
DOI：
10.1111/mpp.12182
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发表时间：
2015
影响因子：
4.9
通讯作者：
Moriyama H and Fukuhara T.
中科院分区：
文献类型：
--
作者：
Yoshii A;Omatsu T;Katayama Y;Koyama S;Mizutani T;Moriyama H and Fukuhara T.
卡苏甘霉素（KSM）是一种独特的氨基糖苷类抗生素，已在一些国家用于控制许多植物细菌和真菌疾病。抗KSM -酸霉的出现。分别引起水稻细菌性褐条病和水稻细菌性谷粒腐病和水稻细菌性谷苗腐病的阿氏杆菌（avenaea）和谷草伯克氏菌（burkholderia glumae）是有效防治这些病害的严重威胁。先前，我们已经从两种KSM抗性病原体中鉴定出编码KSM 2′- N‐乙酰转移酶的aac（2′）‐IIagene。虽然这两个物种的所有KSM耐药菌株都具有aac（2’）‐基因，但只有a。avenaestrain 83表现出较强的耐药性。在本研究中，动力学分析表明菌株83中AAC（2’）‐IIa的146位氨基酸从丝氨酸替换为苏氨酸与抗性增加无关。a的全草图基因组分析。avenae83表明，aac（2’）‐IIagene由新的IncP‐1β质粒pAAA83携带，而其他菌株的遗传载体IncP基因组岛则插入到它们的染色体中。菌株83与其他菌株之间的aac（2’）‐IIain启动子区域核苷酸的差异表明有额外的转录起始位点，导致菌株83的aac（2’）‐IIain转录增加。此外，pAAA83的生物学特性表明它可以通过偶联转移并在宿主细胞中维持。这些结果表明，aac（2’）‐iiagen至少通过两种途径获得，并且包括aac（2’）‐iiagen和下游基因在内的基因模块可能是抗生素耐药性传播的重要单位。
A unique aminoglycoside antibiotic, kasugamycin (KSM), has been used to control many plant bacterial and fungal diseases in several countries. The emergence of KSM‐resistantAcidovorax avenaessp.avenaeandBurkholderia glumae, which cause rice bacterial brown stripe and rice bacterial grain and seedling rot, respectively, is a serious threat for the effective control of these diseases. Previously, we have identified theaac(2′)‐IIagene, encoding a KSM 2′‐N‐acetyltransferase, from both KSM‐resistant pathogens. Although all KSM‐resistant isolates from both species possess theaac(2′)‐IIagene, onlyA. avenaestrain 83 showed higher resistance than other strains. In this research, kinetic analysis indicates that an amino acid substitution from serine to threonine at position 146 of AAC(2′)‐IIa in strain 83 is not involved in this increased resistance. Whole draft genome analysis ofA. avenae83 shows that theaac(2′)‐IIagene is carried by the novel IncP‐1β plasmid pAAA83, whereas the genetic carrier of other strains, the IncP genomic island, is inserted into their chromosomes. The difference in the nucleotides of the promoter region ofaac(2′)‐IIabetween strain 83 and other strains indicates an additional transcription start site and results in the increased transcription ofaac(2′)‐IIain strain 83. Moreover, biological characterization of pAAA83 demonstrates that it can be transferred by conjugation and maintained in the host cells. These results demonstrate that acquisition of theaac(2′)‐IIagene takes place in at least two ways and that the gene module, which includesaac(2′)‐IIaand the downstream gene, may be an important unit for the dissemination of antibiotic resistance.