Previous Article | Next Article ![]()
Applied and Environmental Microbiology, May 2001, p. 2156-2166, Vol. 67, No. 5
Dipartimento di Scienza degli Alimenti,
Università degli Studi di Napoli "Federico II," 80055 Portici,1 and Dipartimento di
Biologia, Difesa, e Biotecnologie Agro-Forestali, Università
degli Studi della Basilicata, 85100 Potenza,2 Italy
Received 29 September 2000/Accepted 18 February 2001
Thermophilic streptococci play an important role in the manufacture
of many European cheeses, and a rapid and reliable method for their
identification is needed. Randomly amplified polymorphic DNA (RAPD) PCR
(RAPD-PCR) with two different primers coupled to hierarchical cluster
analysis has proven to be a powerful tool for the classification and
typing of Streptococcus thermophilus, Enterococcus faecium, and Enterococcus
faecalis (G. Moschetti, G. Blaiotta, M. Aponte, P. Catzeddu, F. Villani, P. Deiana, and S. Coppola, J. Appl. Microbiol.
85:25-36, 1998). In order to develop a fast and
inexpensive method for the identification of thermophilic streptococci,
RAPD-PCR patterns were generated with a single primer (XD9), and the
results were analyzed using artificial neural networks (Multilayer
Perceptron, Radial Basis Function network, and Bayesian network) and
multivariate statistical techniques (cluster analysis, linear
discriminant analysis, and classification trees). Cluster analysis
allowed the identification of S. thermophilus but not of
enterococci. A Bayesian network proved to be more effective than a
Multilayer Perceptron or a Radial Basis Function network for the
identification of S. thermophilus, E. faecium, and E. faecalis using simplified RAPD-PCR
patterns (obtained by summing the bands in selected areas of the
patterns). The Bayesian network also significantly outperformed two
multivariate statistical techniques (linear discriminant analysis
and classification trees) and proved to be less
sensitive to the size of the training set and more robust in
the response to patterns belonging to unknown species.
0099-2240/01/$04.00+0 DOI: 10.1128/AEM.67.5.2156-2166.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.
Comparison of Statistical Methods for Identification of
Streptococcus thermophilus, Enterococcus
faecalis, and Enterococcus faecium from
Randomly Amplified Polymorphic DNA Patterns
*
Corresponding author. Mailing address: Dipartimento di
Biologia, Difesa, e Biotecnologie Agro-Forestali, Università
degli Studi della Basilicata, Campus di Macchia Romana, 85100 Potenza, Italy. Phone: 39-0971-205561. Fax: 39-0971-205561. E-mail:
parente{at}unibas.it.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»