Bendouah Zohra, Barbeau Jean, Hamad Walid Abou, Desrosiers Martin
Department of Otolaryngology-Head and Neck Surgery, University of Montreal, Canada.
Am J Rhinol. 2006 Sep-Oct;20(5):434-8. doi: 10.2500/ajr.2006.20.2930.
Bacterial biofilms are increasingly implicated in the pathogenesis of chronic disease and have been established in several chronic ear, nose, and throat conditions, including chronic sinusitis (CRS). However, this relies on specialized imaging methods not widely available. We wished to assess the capacity of an easily performed, inexpensive in vitro test to assess biofilm production by bacteria recovered from individuals with CRS with or without nasal polyposis.
Bacterial isolates were recovered from patients consulting an academic tertiary rhinology practice. Biofilm formation was determined with an in vitro staining method using crystal violet. Ten isolates of Pseudomonas aeruginosa, Staphylococcus aureus, and 11 of coagulase-negative staphylococcus from patients with CRS having previously undergone endoscopic sinus surgery for >1 year were assessed. Samples were cultured 24 hours at 37 degrees C on 96-well plates in tryptic soy broth 0.5% glucose medium. After staining with crystal violet, optical density at 570 nm was measured to quantify biofilm production. Biofilm-forming capacity was compared with positive and negative controls for each species obtained from commercial sources.
Positive controls all grew biofilms, with a tendency of lesser biofilm formation at higher dilutions. Twenty-two of 31 clinical samples produced a biofilm greater or equal to the positive control. Biofilm was recovered consistently for all three species studied.
This in vitro assessment method is capable of detecting biofilm-forming capacity in bacteria recovered from individuals with CRS. This simple assay may be a useful complement to existing techniques for clinical research.
细菌生物膜越来越多地被认为与慢性病的发病机制有关，并且已在包括慢性鼻窦炎（CRS）在内的多种慢性耳、鼻、喉疾病中得到证实。然而，这依赖于尚未广泛应用的专业成像方法。我们希望评估一种易于操作且成本低廉的体外试验，以评估从患有或未患有鼻息肉的CRS患者中分离出的细菌产生生物膜的能力。
从一家学术性三级鼻科学诊所就诊的患者中分离细菌菌株。使用结晶紫通过体外染色法测定生物膜形成。对10株铜绿假单胞菌、金黄色葡萄球菌菌株以及11株来自CRS患者且此前已接受内镜鼻窦手术超过1年的凝固酶阴性葡萄球菌菌株进行评估。样本在含有0.5%葡萄糖的胰蛋白胨大豆肉汤中，于96孔板中在37℃培养24小时。用结晶紫染色后，测量570nm处的光密度以量化生物膜的产生。将每种细菌的生物膜形成能力与从商业来源获得的阳性和阴性对照进行比较。
阳性对照均形成了生物膜，在较高稀释度下生物膜形成有减少的趋势。31份临床样本中有22份产生的生物膜大于或等于阳性对照。在所研究的所有三种细菌中均一致检测到生物膜。
这种体外评估方法能够检测从CRS患者中分离出的细菌的生物膜形成能力。这种简单的检测方法可能是临床研究现有技术的有益补充。
