Rapid characterization of Salmonella strains with direct chemical ionization pyrolysis

Taş, A. Cüneyt; Waart, J. de; Bouwman, Jordy; Brauw, M.C. ten Noever de; Greef, J. van der

doi:10.1016/0165-2370(87)85039-8

Cited by 33 publications

(5 citation statements)

References 12 publications

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“…Other instrumental detection systems which are or have been evaluated for the identification of bacteria including E. coli are the recognition of total cell protein profiles (Kersters & DeLey 1980) and mass spectrometry (Tas et al 1987). Recognition of radioactively-labelled total cell proteins by a /3-scanner has now been developed to a commercially available system for the rapid identification of bacteria (Ambis, San Diego, USA).…”

Section: N S T R U M E N T a L Methodsmentioning

confidence: 99%

Methods for the detection and isolation of Escherichia coli including pathogenic strains

Hofstra¹,

Veld²

1988

J Appl Microbiol

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Section: N S T R U M E N T a L Methodsmentioning

confidence: 99%

Methods for the detection and isolation of Escherichia coli including pathogenic strains

Hofstra¹,

Veld²

1988

J Appl Microbiol

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“…The system, commercialized by Hewlett-Packard (Palo Alto, CA), includes a computer-aided analysis of the profiles obtained and a comparison with over 500 specific profiles. The third identification system discussed here is the use of pyrolysis mass spectrometry (py-MS) for bacterial identification (242). This method implies direct chemical ionization pyrolysis of bacteria and mass spectrometric analysis of the degradation products.…”

Section: Rapid Instrumental Identificationsmentioning

confidence: 99%

“…This method implies direct chemical ionization pyrolysis of bacteria and mass spectrometric analysis of the degradation products. Diglycerides, the degradation products of phospholipids, are the most important molecules for bacterial identification (242). Py-MS has been applied to Salmonella strains and to other Enterobacteriaceae (243,244).…”

Section: Rapid Instrumental Identificationsmentioning

confidence: 99%

Changing perspectives in food microbiology: Implementation of rapid microbiological analyses in modern food processing

Veld

Hartog

Hofstra

1988

Food Reviews International

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This review article summarizes the perspective for the introduction of novel microbiological techniques into modern food manufacturing and processing. Changes are discussed that have occurred recently in the microbiological control of food operations (process microbiology)-for example, the "hazard analysis critical control point" (HACCP) concept, which can be elaborated to a longitudinal integrated chain assessment by monitoring critical control points. In addition, we describe the recent developments in rapid analytical methodology that can be implemented under these concepts. These techniques are based on two major approaches; that is, they are either aimed at estimating the total microbial load as a hygiene parameter, or at detecting and enumerating specific pathogenic or toxigenic microorganisms and their metabolites. We conclude that, at this moment, several of these methods are significant improvements compared with the conventional techniques. However their use in preventive quality assurance by integrated chain assessment, as well as in routine food (end product) control, has been limited to certain areas of the food industries as yet.

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“…A problem with this approach is the loss of high-mass information caused by the pyrolysis and thermal degradation of molecules into low-molecular-weight species and the extensive fragmentation associated with EI. Several reports have appeared in the literature for chemical ionization (CI) of microorganisms. − In the direct chemical ionization (DCI) approach, pyrolysis is carried out within the vacuum chamber. Pyrolysis and DCI in the ion source has the advantage of enhanced sample-transfer characteristics, but a disadvantage is the potential for increased source contamination.…”

mentioning

confidence: 99%

Differentiation of Microorganisms Based on Pyrolysis-Ion Trap Mass Spectrometry Using Chemical Ionization

Wolf

1998

Anal. Chem.

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The ability to differentiate microorganisms using pyrolysision trap mass spectrometry was demonstrated for five Gram-negative disease-causing organisms: Brucella melitensis, Brucella suis, Vibrio cholera, Yersinia pestis, and Francisella tularensis. Bacterial profiles were generated for gamma-irradiated bacterial samples using pyrolytic methylation and compared for electron ionization and chemical ionization using several liquid reagents with increasing proton affinities. Electron ionization combined with pyrolysis caused extensive fragmentation, resulting in a high abundance of lower mass ions and diminishing the diagnostic value of the technique for compound identification and bacterial profiling. Chemical ionization reduced the amount of fragmentation due to ionization while enhancing the molecular ion region of the fatty acids. As the proton affinity of the reagent increased, the protonated molecular ions of the fatty acids became the predominant ions observed in the mass spectrum. As a result, chemical ionization was shown to be more effective than electron ionization in bacterial profiling. Whereas the bacteria could be distinguished at the Genera level using electron ionization, further differentiation to the subspecies level was possible using chemical ionization. The greatest separation among the five test organisms, in terms of Euclidean distances, was obtained using ethanol as the chemical ionization reagent and using pooled masses representing specific fatty acid biomarkers rather than total ion profiles.

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Rapid characterization of Salmonella strains with direct chemical ionization pyrolysis

Cited by 33 publications

References 12 publications

Methods for the detection and isolation of Escherichia coli including pathogenic strains

Methods for the detection and isolation of Escherichia coli including pathogenic strains

Changing perspectives in food microbiology: Implementation of rapid microbiological analyses in modern food processing

Differentiation of Microorganisms Based on Pyrolysis-Ion Trap Mass Spectrometry Using Chemical Ionization

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