在Acinetobacter nosocomialis中以等离子体为媒介的blaGES-24:遗传背景和耐药性概况
Raita Yano1, Shizuo Kayama2, Masato Suzuki3
1Project Research Center for Nosocomial Infectious Diseases, Hiroshima University, Hiroshima City, Hiroshima, Japan; Department of Antimicrobial Resistance, Hiroshima University Graduate School of Biomedical & Health Sciences, Hiroshima City, Hiroshima, Japan; Department of Surgery, Graduate School of Biomedical & Health Sciences, Hiroshima University, Hiroshima City, Hiroshima, Japan.
Journal of global antimicrobial resistance
|October 15, 2025
概括
在Acinetobacter spp.中发现了一种新的GES型β-乳酸酶,GES-24. 这种酶表现出卡巴酶活性,但对某些β-乳酸具有较弱的水解功能,这表明它是混合等离子体的起源.
科学领域:
- 微生物学 微生物学
- 遗传学 是一个遗传学.
- 生物化学 生化学
背景情况:
- 这种细菌是Acinetobacter spp. 是重要的机会性病原体.
- 产生β-乳糖酶的菌株的出现构成了全球健康威胁.
- GES型β-乳糖酶是一种赋予对β-乳糖抗生素耐药性的酶类.
研究的目的:
- 描述新型GES-24β-乳酸酶的遗传和表型特性.
- 为了研究GES-24活动和耐药性配置文件的分子基础.
- 为了了解blaGES-24基因的进化起源.
主要方法:
- 使用Illumina MiSeq和牛津纳米孔对Acinetobacter nosocomialis MS5394的全基因组测序.
- 对抗性基因含量和序列的pAC-GES-24的等离子体分析.
- 位点定向突变发生,以评估氨基酸替代的功能影响.
- 对表达GES变异的大肠杆菌进行抗微生物敏感性测试.
主要成果:
- 该blaGES-24基因位于一个153kb的等离子体上,pAC-GES-24.
- 质粒pAC-GES-24表现出混合骨干,可能来自携带blaNDM和blaOXA.的质粒.
- 与其他GES变体相比,GES-24具有碳烯酶活性,但对CTX,CAZ,AZT和CFPM的水解活性较低.
- 在GES-24和同类GES酶之间,在62,104和170位的氨基酸差异被确定.
结论:
- GES-24是一种GES型β-乳酸酶,具有卡巴酶活性和对特定β-乳酸酶的有限水解能力.
- 携带blaGES-24的等离子体很可能是不同等离子体元素的重组的结果.
- 需要进一步的研究来了解GES-24的临床影响.
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