A sheep model for the study of biofilms in rhinosinusitis
A sheep model for the study of biofilms in rhinosinusitis
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DOI：
10.2500/ajr.2007.21.3032
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发表时间：
2007-05-01
期刊：
影响因子：
--
通讯作者：
Wormald, Peter-John
中科院分区：
文献类型：
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作者：
Ha, Kien R.;Psaltis, Alkis J.;Wormald, Peter-John
背景：细菌生物膜存在于囊性纤维化、胆脂瘤和渗出性中耳炎等慢性疾病中。最近，对鼻窦炎患者粘膜组织中它们的检测表明，它们与这种情况的发病机制有关。我们利用绵羊实验性感染金黄色葡萄球菌的动物模型来研究生物被膜与鼻窦炎之间的可能联系。方法：24只绵羊接受了双侧鼻内窥镜手术，以确定其额部开口。根据术前随机化处理额窦：(1)口左侧通畅，(2)口左侧通畅并细菌灌输，(3)口闭塞，(4)口闭塞，细菌灌输。第7天取额黏膜，用激光共聚焦显微镜(CSLM)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)观察生物膜的存在情况。结果：3种方法对生物膜的检出率不同。扫描电子显微镜观察到86%(n=36)的鼻窦存在可被解释为生物膜的三维结构。这些结构在所有四个研究组中都可以看到。其他两种方法的检出率在CSLM中要低得多，在所分析的鼻窦中，48%(n=20)有生物膜，而只有29%(n=12)的鼻窦有透射电子显微镜。与扫描电子显微镜不同，这两种模式只检测到随机滴入细菌的鼻窦中的细菌生物膜。结论：在该鼻窦炎动物模型中细菌生物膜的证明进一步支持了生物膜可能在该疾病的发病机制中发挥作用的假说。上述三种方法检测生物膜的灵敏度和特异度有明显差异。CSLM似乎是最客观的技术。扫描电子显微镜和透射电子显微镜固有的缺陷、采样误差和主观性使得它们在记录生物膜存在时不太可靠。
Background: Bacterial biofilms have been shown in chronic diseases such as cystic fibrosis, cholesteatoma, and otitis media with effusion. Recently, their detection on the mucosal tissue of sinusitis patients has implicated them in the pathogenesis of this condition. We present an animal model using sheep experimentally infected with Staphylococcus aureus to study the possible association between biofilm and sinusitis.Methods: Twenty-four sheep underwent bilateral endoscopic sinus surgery to identify their frontal ostia. The frontal sinuses were treated in one of the following ways according to preoperative randomization: (1) ostium left patent, (2) ostium left patent and bacteria instilled, (3) ostium occluded, or (4) ostium occluded and bacteria instilled. The frontal mucosa was harvested at day 7 and examined for biofilm presence using confocal scanning laser microscopy (CSLM) as well as scanning electron microscopy (SEM) and transmission electron microscopy (TEM).Results: All three modalities showed different rates of biofilm detection. Three-dimensional structures that could be interpreted as biofilms were documented in 86% (n = 36) of the sinuses analyzed using SEM. These structures were seen in all four study groups. The detection rate using the other two modalities was much lower with CSLM, showing biofilms in 48% (n = 20) and TEM in only 29% (n = 12) of the sinuses analyzed. Unlike SEM, these two modalities only detected bacterial biofilms in sinuses randomized to bacterial instillation.Conclusion: The demonstration of bacterial biofilms in this animal model of sinusitis further supports the hypotheses that biofilms may play a role in the pathogenesis of this condition. There is an obvious discrepancy in the sensitivity and specificity of biofilm detection using the three modalities mentioned. CSLM appears to be the most objective technique. The inherent flaws, sampling error, and subjectivity involved in SEM and TEM make these less reliable in documenting biofilm existence.