Phosphorylcholine decreases early inflammation and promotes the establishment of stable biofilm communities of nontypeable Haemophilus influenzae strain 86-028NP in a chinchilla model of otitis media
Phosphorylcholine decreases early inflammation and promotes the establishment of stable biofilm communities of nontypeable Haemophilus influenzae strain 86-028NP in a chinchilla model of otitis media
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DOI：
10.1128/iai.01691-06
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发表时间：
2007-02-01
影响因子：
3.1
通讯作者：
Swords, W. Edward
中科院分区：
文献类型：
--
作者：
Hong, Wenzhou;Mason, Kevin;Swords, W. Edward
不可分型流感嗜血杆菌（NTHi）是中耳炎的主要病原体。NTHi疾病期间发生的许多炎症是由细菌表面的低脂糖（LOS）引起的。磷酰胆碱（PCho）以相位可变的方式添加到一些LOS形式中，这些PCho（+）变体在体内占主导地位。因此，我们想知道这种修饰是否在感染期间具有一些优势。用栗鼠（chinchilla lanigera）中耳炎模型比较了中耳炎分离株（NTHi菌株86-028NP）与等基因PCho转移酶（licD）突变株的毒力。与感染NTHi 86-028NP的动物相比，感染NTHi 86-028NP的动物表现出早期炎症增加和细菌计数延迟增加。与接种物纯化的LOS相比，从龙猫传代的NTHi 86-028NP纯化的LOS的PCho含量增加。感染后长达14天，两株毒株均从中耳液中恢复。感染NTHi 86-028NP后7天和14天，在安乐死动物的中耳可见宏观生物膜。相反，感染NTHi 86-028NP licD的动物在感染后7天观察到较少的生物膜，感染NTHi 86-028NP licD的动物在感染后14天没有可见的生物膜。荧光抗体染色显示生物膜内PCho（+）变异，与我们之前体外组织培养细胞的结果相似（S. L. West-Barnette， A. Rockel, and W. E. Swords，《感染》）。免疫学。74:1828-1836,2006)。同时感染两种毒株比例相等的动物，每一种毒株的持久性相等，疾病的严重程度略高。因此，我们得出结论，PCho通过减少宿主炎症反应和促进稳定生物膜群落的形成来促进NTHi感染和持久性。
Nontypeable Haemophilus influenzae (NTHi) is a leading causative agent of otitis media. Much of the inflammation occurring during NTHi disease is initiated by lipooligosaccharides (LOS) on the bacterial surface. Phosphorylcholine (PCho) is added to some LOS forms in a phase-variable manner, and these PCho(+) variants predominate in vivo. Thus, we asked whether this modification confers some advantage during infection. Virulence of an otitis media isolate (NTHi strain 86-028NP) was compared with that of an isogenic PCho transferase (licD) mutant using a chinchilla (Chinchilla lanigera) model of otitis media. Animals infected with NTHi 86-028NP licD demonstrated increased early inflammation and a delayed increase in bacterial counts compared to animals infected with NTHi 86-028NP. LOS purified from chinchilla-passed NTHi 86-028NP had increased PCho content compared to LOS purified from the inoculum. Both strains were recovered from middle ear fluids as long as 14 days postinfection. Biofilms were macroscopically visible in the middle ears of euthanized animals infected with NTHi 86-028NP 7 days and 14 days postchallenge. Conversely, less dense biofilms were observed in animals infected with NTHi 86-028NP licD 7 days postinfection, and none of the animals infected with NTHi 86-028NP licD had a visible biofilm by 14 days. Fluorescent antibody staining revealed PCho(+) variants within biofilms, similar to our prior results with tissue culture cells in vitro (S. L. West-Barnette, A. Rockel, and W. E. Swords, Infect. Immun. 74:1828-1836, 2006). Animals coinfected with equal proportions of both strains had equal persistence of each strain and somewhat greater severity of disease. We thus conclude that PCho promotes NTHi infection and persistence by reducing the host inflammatory response and by promoting formation of stable biofilm communities.