近日，来自加拿大阿尔伯塔大学的研究者在致病菌鲍氏不动杆菌的分子保护层中发现了其“裂缝”，这将为新型抗生素的开发提供一些线索，鲍氏不动杆菌是20世纪70年代首次发现，在上个世纪，该菌已经产生了极强的耐药性。
研究者Feldman识别出了一种新的机制，即鲍氏不动杆菌可以以糖蛋白类来保护其菌体表面免受伤害。这就引导这研究者去拉开另一个发现，如果鲍氏不动杆菌不能产生糖蛋白类，则细菌将变得低毒而且会产生较少的生物被膜（生物被膜可以保护细菌免于抗生素伤害）。
鲍氏不动杆菌是一种狡猾的接触传染性病菌，可以在医院内广泛传染。这种细菌仅仅通过身体接触就可以在人群中进行传染，而且在坚硬表面可以生存数日，并且可以以导尿管和呼吸器为寄居地。不动杆菌感染也可以通过咳嗽和打喷嚏来传播。
免疫力低下的病人通常对鲍氏不动杆菌有较强的敏感性，而且细菌感染伤口后可以扩散至肺部、血液中以及脑部。研究者表示需要更为深入的工作来理解细菌是如何产生多糖类物质的，研究者希望他们当前的研究可以为研发抵御或阻止多糖类产生的药物提供思路，并且研究者希望通过深入研究最终找到彻底杀灭鲍氏不动杆菌的方法。
这项研究已于6月7日刊登在了国际著名杂志PLoS Pathogens上。（生物谷Bioon.com）
编译自：Killer Hospital Bacteria: Cracking a Superbug's Armour
编译者：天使托
doi:10.1371/journal.ppat.1002758
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Identification of a General O-linked Protein Glycosylation System in Acinetobacter baumannii and Its Role in Virulence and Biofilm Formation
Jeremy A. Iwashkiw1, Andrea Seper2, Brent S. Weber1, Nichollas E. Scott1,3, Evgeny Vinogradov4, Chad Stratilo5, Bela Reiz6, Stuart J. Cordwell3, Randy Whittal6, Stefan Schild2, Mario F. Feldman1*
Acinetobacter baumannii is an emerging cause of nosocomial infections. The isolation of strains resistant to multiple antibiotics is increasing at alarming rates. Although A. baumannii is considered as one of the more threatening “superbugs” for our healthcare system, little is known about the factors contributing to its pathogenesis. In this work we show that A. baumannii ATCC 17978 possesses an O-glycosylation system responsible for the glycosylation of multiple proteins. 2D-DIGE and mass spectrometry methods identified seven A. baumannii glycoproteins, of yet unknown function. The glycan structure was determined using a combination of MS and NMR techniques and consists of a branched pentasaccharide containing N-acetylgalactosamine, glucose, galactose, N-acetylglucosamine, and a derivative of glucuronic acid. A glycosylation deficient strain was generated by homologous recombination. This strain did not show any growth defects, but exhibited a severely diminished capacity to generate biofilms. Disruption of the glycosylation machinery also resulted in reduced virulence in two infection models, the amoebae Dictyostelium discoideum and the larvae of the insect Galleria mellonella, and reduced in vivo fitness in a mouse model of peritoneal sepsis. Despite A. baumannii genome plasticity, the O-glycosylation machinery appears to be present in all clinical isolates tested as well as in all of the genomes sequenced. This suggests the existence of a strong evolutionary pressure to retain this system. These results together indicate that O-glycosylation in A. baumannii is required for full virulence and therefore represents a novel target for the development of new antibiotics.
