title: Defining and using microbial spectral databases.
abstract: This work shows how fingerprints of mass spectral patterns from microbial isolates are affected by variations in instrumental condition, by sample environment, and by sample handling factors. It describes a novel method by which pattern distortions can be mathematically corrected for variations in factors not amenable to experimental control. One uncontrollable variable is "between-batch" differences in culture media. Another, relevant for determination of noncultured extracts, is differences between the cells' environmental experience (e.g., starved environmental extracts versus cultured standards). The method suggests that, after a single growth cycle on a solid medium (perhaps, a selective one), pyrolysis MS spectra of microbial isolates can be algorithmically compensated and an unknown isolate identified using a spectral database defined by culture on a different (perhaps, nonselective) medium. This reduces identification time to as few as 24 h from sample collection. The concept also proposes a possible way to compensate certain noncultured, nonisolated samples (e.g., cells concentrated from urine or impacted from aerosol or semi-selectively extracted by immunoaffinity methods from heavily contaminated matrices) for identification within half an hour. Using the method, microbial mass spectra from different labs can be assembled into coherent databases similar to those routinely used to identify pure compounds. This type of data treatment is applicable for rapid detection in biowarfare and bioterror events as well as in forensic, research, and clinical laboratory contexts.
authors.affiliation: National Center for Toxicological Research, USFDA, Jefferson, Arkansas 72079, USA. jwilkes@nctr.fda.gov
authors.forename: Jon G
authors.initials: JG
authors.lastname: Wilkes
authors.forename: Katherine L
authors.initials: KL
authors.lastname: Glover
authors.forename: Manuel
authors.initials: M
authors.lastname: Holcomb
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Rafii
authors.forename: Xiaoxi
authors.initials: X
authors.lastname: Cao
authors.forename: John B
authors.initials: JB
authors.lastname: Sutherland
authors.forename: Susan A
authors.initials: SA
authors.lastname: McCarthy
authors.forename: Simon
authors.initials: S
authors.lastname: Letarte
authors.forename: Michel J
authors.initials: MJ
authors.lastname: Bertrand
mesh_terms: D000465:Algorithms; D001419:Bacteria / Q000737:chemistry* / Q000254:growth & development; D003470:Culture Media; D016208:Databases, Factual; D004926:Escherichia coli / Q000737:chemistry / Q000254:growth & development; D013058:Mass Spectrometry
chemical_list: D003470:Culture Media