Integration of Raman microscopy, differential interference contrast microscopy, and attenuated total reflection Fourier transform infrared spectroscopy to investigate chlorhexidine spatial and temporal distribution in Candida albicans biofilms
Integration of Raman microscopy, differential interference contrast microscopy, and attenuated total reflection Fourier transform infrared spectroscopy to investigate chlorhexidine spatial and temporal distribution in Candida albicans biofilms
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DOI：
10.1016/s0167-7012(01)00268-8
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发表时间：
2001-09-01
影响因子：
2.2
通讯作者：
Tyler, BJ
中科院分区：
文献类型：
--
作者：
Suci, PA;Geesey, GG;Tyler, BJ
采用衰减全反射傅里叶变换红外光谱（ATR-FTIR）和拉曼显微镜（RM）两种光谱技术，研究了二光酸氯己定（CHG）在白色念珠菌（CA）生物膜中的转运。利用这两种振动光谱对生物膜的不同（体积）区域进行采样，使其成为互补技术，建立了简单的数学模型来分析ATR-FTIR和RM数据，以获得描述通过CA生物膜的有效扩散系数，CA生物膜主要由酵母和菌丝形式组成，还有一些假菌丝。已经融合的生物膜上部区域(即…完全覆盖锗（Ge）基质的生物膜主要由缠绕在一起的菌丝团组成，菌丝在胚管之间有大约10到50微米的开口。ATR-FTIR动力学数据曲线的定量分析表明，与CHG在水中的扩散系数相比，CHG通过200-mum厚的汇合生物膜的有效扩散系数降低了0.1 ~ 0.3倍。从RM数据分析得到的有效扩散系数始终高于ATR-FTIR数据显示的有效扩散系数，这表明生物膜底部附近的区域比外层的传输更受阻。从较厚的膜上获得的ATR-FTIR和RM数据分析表明，CHG对生物膜组分的吸附是生物膜施加的运输限制的很大一部分原因。两种生物膜的ATR-FTIR和RM数据的比较表明，CHG的吸附位点更集中在界面区域，而不是在整体生物膜中。ATR-FTIR和RM测量结果的比较表明，为了预测运输，这些相对较厚的CA生物膜可以近似地建模为均匀的薄平面。因此，这些生物膜为抗菌转运和抗菌作用动力学之间的关系的初步研究提供了一个相对易于处理的模型系统。(C) 2001年Elsevier Science B.V.出版
Two spectroscopic techniques, attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and Raman microscopy (RM), were used to characterize transport of chlorhexidine digluconate (CHG) in Candida albicans (CA) biofilms. Different (volumetric) regions of the biofilm are sampled by these two vibrational spectroscopies making them complementary techniques, Simple mathematical models were developed to analyze ATR-FTIR and RM data to obtain an effective diffusion coefficient describing transport through CA biofilms, CA biofilms were composed primarily of yeast and hyphal forms, with some pseudohyphae. Upper regions of biofilms that had become confluent, (i.e.. biofilms that completely covered the germanium (Ge) substratum) were composed primarily of a tangled mass of hyphae with openings between germtubes about 10 to 50 mum across. Quantitative analysis of ATR-FTIR kinetic data curves indicated that the effective diffusion coefficient for transport of CHG through confluent biofilms about 200-mum thick was: reduced 0.1 to 0.3 times compared to the diffusion coefficient for CHG in water. Effective diffusion coefficients obtained from analysis of RM data were consistently higher than those indicated by ATR-FTIR data suggesting that transport is more hindered in regions near the base of the biofilm than in the outer layers. Analysis of both ATR-FTIR and RM data obtained from thicker films indicated that adsorption of CHG to biofilm components was responsible for a substantial portion of the transport limitation imposed by the biofilm. Comparison of ATR-FTIR and RM data for both types of biofilms indicated that sites of CHG adsorption were more concentrated in the interfacial region than in the bulk biofilm. Comparison of results for ATR-FTIR and RM measurements suggests that these relatively thick CA biofilms can be modeled, for purposes of predicting transport, approximately as a homogeneous thin planar sheet. Thus, these biofilms offer a relatively tractable model system for initial investigations of the relation between antimicrobial transport and kinetics of antimicrobial action. (C) 2001 Published by Elsevier Science B.V.