信息摘要：
2026年，中国科学院微生物研究所团队在mLife期刊发表研究论文《ISAba1-mediated crp-osmC amplification enhances host-associated fitness in Acinetobacter baumannii》(DOI: 10.1002/mlf2.70105)，研究中使用LUYOR-3421荧光成像系统对鲍曼不动杆菌菌落的mCherry红色荧光信号进行观察与成像，用于crp-osmC基因簇扩增菌株与mCherry标记对照菌株在体外竞争培养及小鼠呼吸道和肠道定植模型中的定量比较分析，为揭示ISAba1介导的crp-osmC基因扩增增强鲍曼不动杆菌宿主适应性的机制研究提供关键实验证据。
中国科学院微生物研究所将LUYOR-3421用于鲍曼不动杆菌菌落mCherry荧光观察实验
2026年，中国科学院微生物研究所团队在mLife期刊发表研究论文《ISAba1-mediated crp-osmC amplification enhances host-associated fitness in Acinetobacter baumannii》，研究中使用LUYOR-3421荧光成像系统用于鲍曼不动杆菌菌落mCherry荧光观察实验，对体外竞争培养及小鼠感染实验后回收的肺组织匀浆和粪便样本涂布平板上的菌落进行mCherry红色荧光成像，LUYOR-3421荧光成像系统通过分别在明场和荧光通道下计数菌落数量来计算竞争指数，用于评估crp-osmC基因簇扩增菌株在体外和小鼠体内的竞争适应性。LUYOR-3421荧光成像系统在基于mCherry荧光标记的细菌竞争感染实验中承担关键的菌落荧光定量环节，通过对平板菌落进行明场与红色荧光双通道成像，准确区分mCherry标记对照菌株与未标记的crp-osmC扩增菌株，确保后续竞争指数计算的准确性和可重复性，为crp-osmC扩增菌株宿主适应性增强的结论提供可靠的实验数据支撑。
中国科学院微生物研究所位于北京，是我国微生物学研究的综合性研究机构。该研究团队围绕鲍曼不动杆菌的耐药与宿主适应性机制开展研究，发现ISAba1插入序列介导的crp-osmC基因簇扩增在临床流行ST2型菌株中显著富集，通过实验模拟基因扩增证实其可显著增强细菌生长速率、竞争适应性、小鼠血清存活能力及体内定植能力。转录组分析揭示crp-osmC扩增通过促进苯丙氨酸代谢、铁载体生物合成和硫代谢等代谢灵活性与营养获取通路增强宿主适应性。同时，基因扩增伴随生物膜形成减弱和多种抗生素敏感性升高，揭示了宿主适应性与耐药性之间的权衡关系。LUYOR-3421荧光成像系统用于的菌落mCherry荧光观察实验作为定量评估细菌体内竞争适应性的关键手段，为上述分子机制的确认提供了重要实验证据。
本实验采用LUYOR-3421作为鲍曼不动杆菌菌落mCherry荧光观察实验的核心成像设备，用于对竞争培养和小鼠感染实验后回收样本涂布平板上的菌落进行明场与mCherry荧光双通道成像。实验将携带mCherry标记的对照菌株19606 (pKFAb:mCherry)与crp-osmC扩增菌株19606 (pKFAb:crp-osmC)按1:1比例混合，分别进行体外竞争培养和小鼠鼻腔接种(i.n.)及灌胃(i.g.)感染，在设定时间点回收培养物、肺组织和粪便样本，系列稀释后涂布于LB平板，37°C培养过夜后使用LUYOR-3421荧光成像系统进行菌落成像，分别在明场通道和红色荧光通道下计数菌落数量，计算竞争指数。LUYOR-3421荧光成像系统用于菌落mCherry荧光观察结果表明，crp-osmC扩增菌株在体外竞争培养中竞争指数达3.06±0.88（3 h）和3.45±0.67（6 h），在小鼠呼吸道定植模型中竞争指数为3.56±0.97，肠道定植模型中为2.12±0.79，小鼠血清中竞争指数达3.09±1.84（3 h）和9.00±5.69（6 h），为证实crp-osmC扩增显著增强鲍曼不动杆菌宿主相关适应性提供了直接实验证据。
该研究证实，LUYOR-3421荧光成像系统可用于细菌菌落mCherry红色荧光信号的高通量观察与定量分析，适用于基于荧光标记的细菌竞争感染实验、体内定植适应性评估、菌落表型筛选等微生物学应用场景。LUYOR-3421荧光成像系统在国内外高校和科研院所得到广泛好评，欢迎私信或留言联系上海路阳了解详情！
原文段落
鲍曼不动杆菌菌落mCherry荧光观察实验方法原文
To further evaluate the competitive fitness of the amplified strain in vitro and its colonization potential in vivo, we incorporated a red fluorescent protein marker (mCherry) into the empty vector as control strain 19606 (pKFAb) to enable direct differentiation during co-culture and infection assays. For in vitro competition assays, equal ratios of 19606 (pKFAb:crp-osmC) and 19606 (pKFAb:mCherry) strains were co-cultured in liquid medium, and bacterial counts were determined at 3 and 6 h by plating serial dilutions on LB agar with appropriate antibiotics. The competitive index was calculated as the ratio of crp-osmC amplified strain to mCherry-labeled control strain. For in vivo competition assays, mice were intranasally or orally inoculated with a 1:1 mixture of the two strains. At 24 h post inoculation (hpi), mice were euthanized, and lung tissues or faecal samples were collected, homogenized, and serially diluted for plating. Colonies were counted under both bright field and fluorescence channels using a LUYOR-3421 imaging system to distinguish mCherry-expressing control colonies from non-fluorescent crp-osmC amplified colonies.
鲍曼不动杆菌菌落mCherry荧光观察结果原文
Elevated crp-osmC copy number enhances in vivo colonization and promotes serum resistance. To further evaluate the competitive fitness of the amplified strain in vitro and its colonization potential in vivo, we incorporated a red fluorescent protein marker (mCherry) into the empty vector as control strain 19606 (pKFAb) to enable direct differentiation during co-culture and infection assays. For in vitro competition assays, equal ratios of 19606 (pKFAb:crp-osmC) and 19606 (pKFAb:mCherry) strains were co-cultured in liquid medium. Relative to the 19606 (pKFAb:mCherry) strain, 19606 (pKFAb:crp-osmC) displayed a competitive advantage, with competitive index values of 3.06 ± 0.88 and 3.45 ± 0.67 at 3 and 6 h, respectively. We next evaluated whether the observed advantages extend to a living host. Using murine lung infection and intestinal colonization models, mice were intranasally or orally inoculated with a 1:1 mixture of the two strains. Strain 19606 (pKFAb:crp-osmC) consistently outcompeted 19606 (pKFAb:mCherry) in both pulmonary (competitive index of 3.56 ± 0.97) and intestinal (competitive index of 2.12 ± 0.79) niches, demonstrating a clear competitive advantage at 24 hpi. Moreover, the amplified strain displayed increased survival in mouse serum, with a 3.49 ± 1.34- and 7.05 ± 2.75-fold increase over the control at 3 and 6 h, respectively. When the two strains were co-incubated in mouse serum at a 1:1 ratio, competition assays yielded competitive index values of 3.09 ± 1.84 and 9.00 ± 5.69 at 3 and 6 h, respectively.
研究结论原文
These findings uncover a link between insertion sequence-driven gene amplification and host adaptation, revealing that ISAba1-mediated amplification of the crp-osmC locus enhances host-associated fitness in the globally prevalent ST2 lineage of Acinetobacter baumannii by promoting bacterial growth competitiveness, serum resistance, and host colonization. The accompanying reduction in biofilm formation and increase in antibiotic sensitivity reveal a trade-off between host adaptation and resistance, providing insights into the genetic basis of A. baumannii evolution and its clinical predominance.
DOI:doi.org/10.1002/mlf2.70105
