工程菌雾化吸入使猪气管导管耐药菌生物膜变薄约40%：《电子生物医学》研究厚度由6.08微米降至3.67微米
西班牙巴塞罗那报道 — 一项刊于《电子生物医学》（eBioMedicine）的研究显示，一种经基因改造的「活药」细菌经雾化吸入后，使猪肺部呼吸导管内壁上耐药铜绿假单胞菌（Pseudomonas aeruginosa）生物膜变薄：生物膜厚度由6.08微米降至3.67微米，减少约40%。本稿只报道研究事实，不作个体诊疗建议。
研究团队表示，这是该实验疗法首次在猪身上显示效果，此前仅在小鼠身上验证；猪的肺在大小、结构与免疫反应上与人肺相近。这也是该疗法首次显示可经雾化器给药，雾化器正是人类患者会使用的同类设备。所用细菌为肺炎支原体（Mycoplasma pneumoniae），通常引起轻度肺感染，经基因工程改造后对人无害，并装载了溶解维系生物膜的糖类以及专门针对铜绿假单胞菌的毒素基因。研究人员检查后称，未发现改造菌对猪肺造成损伤的迹象，且未测得其对动物自身气道细菌有可测量的影响。
研究背景是，医院中无法自主呼吸的患者通常靠气管导管维持呼吸，数日内细菌会在导管内定植并形成黏滑的保护层即生物膜，静脉滴注的抗生素难以穿透这层屏障，造成反复感染；在插管患者中，这是呼吸机相关肺炎的已知成因，约四分之一的病例由铜绿假单胞菌引起，该菌常对多种抗生素耐药。
该研究由巴塞罗那基因组调控中心（CRG）与巴塞罗那临床医院 IDIBAPS 研究所合作，动物实验在巴塞罗那大学进行。作者称，研究结果支持未来开展首次人体安全试验。
Inhaled Engineered Bacterium Thins Drug-Resistant Biofilms on Breathing Tubes in Pigs by About 40 Percent: eBioMedicine Study Measures a Fall From 6.08 to 3.67 Micrometers
BARCELONA, Spain — A study published in the journal eBioMedicine found that a genetically modified living medicine, inhaled through a nebulizer, thinned biofilms of antibiotic-resistant Pseudomonas aeruginosa inside breathing tubes in pigs, reducing biofilm thickness from 6.08 to 3.67 micrometers, a reduction of around 40 percent. This item reports the study's facts only and offers no individual medical advice.
The team said it is the first time the experimental treatment, previously shown only in mice, has also worked in pigs, a large animal with lungs similar in size, structure and immune response to human lungs, and the first time it has been shown to be administrable through a nebulizer, the same type of device human patients would use. The treatment uses Mycoplasma pneumoniae, a bacterium that normally causes a mild lung infection, reprogrammed through genetic engineering to be harmless and loaded with genes that dissolve sugars holding a biofilm together, as well as toxins that specifically target Pseudomonas aeruginosa. The researchers said they found no signs of damage caused by the engineered bacterium in the pigs' lungs, and no measurable effect on the animals' own airway bacteria.
In hospital patients who cannot breathe for themselves, a tube is passed into the windpipe, and within days bacteria colonize the inside of that tube and form a protective layer called a biofilm, which intravenous antibiotics struggle to penetrate, causing recurring infections. In intubated patients this is a known cause of ventilator-associated pneumonia, and around one in four cases are caused by Pseudomonas aeruginosa, which is frequently resistant to several types of antibiotics. The study is a collaboration between the Center for Genomic Regulation (CRG) and Hospital Clínic-IDIBAPS, both in Barcelona, with animal studies at the University of Barcelona. The authors say the findings support a future first-in-human safety trial.
来源：《电子生物医学》
发布：GSM·美国（发布链接）
图片来源：图：医院建筑（资料图）。经Wikimedia Commons。 / Photo: a hospital building (file photo). Via Wikimedia Commons.
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