Sensitive Detection of Bacillus anthracis Spores by Immunocapture and Liquid Chromatography鈥揟andem Mass Spectrometry

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• 作者：J茅r么me Chenau ; Fran莽ois Fenaille ; Eric Ezan ; Nathalie Morel ; Patricia Lamourette ; Pierre L. Goossens ; Fran莽ois Becher
• 刊名：Analytical Chemistry
• 出版年：2011
• 出版时间：November 15, 2011
• 年：2011
• 卷：83
• 期：22
• 页码：8675-8682
• 全文大小：845K
• 年卷期：v.83,no.22(November 15, 2011)
• ISSN：1520-6882

文摘

Bacillus anthracis is one of the most dangerous agents of the bioterrorism threat. We present here a sensitive immuno鈥搇iquid chromatography鈥搕andem mass spectrometry (immuno鈥揕C鈥揗S/MS) approach to spore detection in complex environmental samples. It is based on the combined specificity and sensitivity of two techniques: immunocapture and targeted mass spectrometry. The immunocapture step, realized directly on the intact spores, is essential for their selective isolation and concentration from complex environmental samples. After parallel trypsin and Glu-C digestions, proteotypic peptides corresponding to small acid-soluble spore protein-B (SASP-B) are specifically monitored in the multiple reaction monitoring (MRM) mass spectrometry mode. Peptide ratio is carefully monitored and provides an additional level of specificity, which is shown to be highly useful for distinguishing closely related samples and avoiding false-positive/negative results. Sensitivity at the level of the infectious dose is demonstrated, with limits of detection of 7 脳 10³ spores/mL of milk or 10 mg of soil. This mass spectrometry approach is thus complementary to polymerase chain reaction (PCR) techniques.