Samaranayake L P, Tobgi R S, MacFarlane T W
Department of Oral Sciences, Glasgow Dental Hospital and School.
J Med Microbiol. 1994 May;40(5):350-7. doi: 10.1099/00222615-40-5-350.
Respiratory secretions provide an efficient method for protecting the large surface area of the lower respiratory tract. To determine whether lung secretions contribute to antifungal defences, murine bronchoalveolar lavage fluid (BLF) was tested for anti-candidal activity against 49 oral and vaginal isolates belonging to six different Candida species. The yeasts were incubated in unconcentrated, cell-free lavage fluid from Sprague-Dawley rats and then cultured quantitatively to measure residual viability. Experiments with C. albicans indicated that sensitivity to BLF increased in a time- and dose-dependent manner. This activity was heat-stable (56 degrees C) and consistent, irrespective of whether the BLF was derived from rats inoculated (orally) with candida or the uninoculated controls. Of the Candida spp. examined, C. albicans was the most susceptible followed by C. parapsilosis and C. tropicalis, whereas C. krusei, C. guilliermondii and C. glabrata were highly resistant. However, there were differences in susceptibility to BLF among different isolates within a given species. These results indicate that a heat-stable, soluble factor(s) in murine lavage fluid may suppress candidal colonisation of the lower respiratory tract and contribute to the defence mechanisms of the lungs.
呼吸道分泌物为保护下呼吸道的大面积区域提供了一种有效的方法。为了确定肺分泌物是否有助于抗真菌防御，对小鼠支气管肺泡灌洗液（BLF）针对属于六种不同念珠菌属的49株口腔和阴道分离株的抗念珠菌活性进行了测试。将酵母在来自Sprague-Dawley大鼠的未浓缩、无细胞灌洗液中孵育，然后进行定量培养以测量残余活力。白色念珠菌的实验表明，对BLF的敏感性呈时间和剂量依赖性增加。这种活性是热稳定的（56摄氏度）且一致，无论BLF是来自经念珠菌（口服）接种的大鼠还是未接种的对照。在所检测的念珠菌属中，白色念珠菌最敏感，其次是近平滑念珠菌和热带念珠菌，而克柔念珠菌、季也蒙念珠菌和光滑念珠菌高度耐药。然而，在给定物种内的不同分离株之间，对BLF的敏感性存在差异。这些结果表明，小鼠灌洗液中的一种热稳定、可溶性因子可能抑制下呼吸道的念珠菌定植，并有助于肺部的防御机制。
