2016年7月11日 讯 /生物谷BIOON/ --甲型链球菌可以引发危及生命的坏死性筋膜炎，随后其会快速扩散并且破坏机体的软组织，通常治疗甲型链球菌引发的坏死性软组织感染的疗法需要强化治疗，同时进行手术干预；该疾病通常会导致受影响的肢体被截肢。
近日一项刊登于国际杂志JCI Insight上的研究论文中，来自瑞典卡罗琳学院的研究人员通过研究发现证据表明，细菌生物被膜的形成或许是甲型链球菌引发坏死性软组织感染的复杂特性，而生物被膜就是吸附在组织表面上的一大堆细菌聚集体。
文章中，研究者Anna Norrby-Teglund表示，我们发现了一名甲型链球菌引发坏死性软组织感染的患者似乎对抗生素和手术清除伤口的疗法会产生反应，尽管目前并没有甲型链球菌引发相关的疾病症状，但对患者伤口的再次检查或许就可以发现细菌所形成的较厚的生物被膜。随后在三分之一的研究中，研究者这对坏死性软组织感染的患者进行分析都发现了患者机体伤口处生物被膜的存在。
研究者指出，生物被膜和高度的细菌载量、密集型的炎症发生直接相关，而且相比没有生物被膜的伤口组织样本而言，生物被膜的存在往往会导致伤口出现炎症的组织损伤，本文研究结果就表明，生物被膜或许应当被认为是引发链球菌坏死性软组织感染的复杂因子。
生物被膜的形成往往会改善病原体对抗生素的耐受性和反应性，研究者表示，后期他们还将通过更为深入的研究来评估在感染位点中清除甲型链球菌生物被膜的过程或方法对于减缓感染进展的作用。
Biofilm in group A streptococcal necrotizing soft tissue infections
Nikolai Siemens,1 Bhavya Chakrakodi,1 Srikanth Mairpady Shambat,1 Marina Morgan,2 Helena Bergsten,1 Ole Hyldegaard,3 Steinar Skrede,4 Per Arnell,5 Martin B. Madsen,6 Linda Johansson,1 INFECT Study Group,7 Julius Juarez,1 Lidija Bosnjak,1 Matthias Mörgelin,8 Mattias Svensson,1 and Anna Norrby-Teglund1
Necrotizing fasciitis caused by group A streptococcus (GAS) is a life-threatening, rapidly progressing infection. At present, biofilm is not recognized as a potential problem in GAS necrotizing soft tissue infections (NSTI), as it is typically linked to chronic infections or associated with foreign devices. Here, we present a case of a previously healthy male presenting with NSTI caused by GAS. The infection persisted over 24 days, and the surgeon documented the presence of a “thick layer biofilm” in the fascia. Subsequent analysis of NSTI patient tissue biopsies prospectively included in a multicenter study revealed multiple areas of biofilm in 32% of the patients studied. Biopsies associated with biofilm formation were characterized by massive bacterial load, a pronounced inflammatory response, and clinical signs of more severe tissue involvement. In vitro infections of a human skin tissue model with GAS NSTI isolates also revealed multilayered fibrous biofilm structures, which were found to be under the control of the global Nra gene regulator. The finding of GAS biofilm formation in NSTIs emphasizes the urgent need for biofilm to be considered as a potential complicating microbiological feature of GAS NSTI and, consequently, emphasizes reconsideration of antibiotic treatment protocols.