Development of a rapid identification system for Listeria at the species, and Listeria monocytogenes at the serovar level by artificial neural network analysis of Fourier transform infrared spectra [Elektronische Ressource] / Cecilia Alejandra Rebuffo-Scheer

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• Biologie

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• Publié par: technische_universitat_munchen
• Publié le: 01 janvier 2008
• Nombre de lectures: 40
• Langue: English
• Poids de l'ouvrage: 2 Mo

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Institut für Mikrobiologie
Zentralinstitut für Ernährungs-und Lebensmittelforschung Weihenstephan
Technische Universität München


Development of a rapid identification system for Listeria
at the species, and Listeria monocytogenes at the serovar level
by Artificial Neural Network analysis of Fourier Transform
Infrared Spectra


Cecilia A. Rebuffo-Scheer


Vollständiger Abdruck der von der Fakultät Wissenschaftszentrum Weihenstephan für
Ernährung, Landnutzung und Umwelt der Technischen Universität München zur
Erlangung des akademischen Grades eines Doktors der Naturwissenschaften
(Dr. rer. nat.)
genehmigten Dissertation.

Vorsitzender Univ.-Prof. Dr. Dirk Haller
Prüfer der Dissertation 1. Univ.-Prof. Dr. Siegfried Scherer
2. Univ.-Prof. Dr. Dieter Naumann


Die Dissertation wurde am 17.01.2008 bei der Technischen Universität München
eingereicht und durch die Fakultät Wissenschaftszentrum Weihenstephan für
Ernährung, Landnutzung und Umwelt am ……….. angenommen.
Acknowledgement
The PhD thesis presented here has been accomplished at the Institute of Microbiology, ZIEL
Weihenstephan, Technical University of Munich under supervision of Prof. Dr. Siegfried
Scherer.
My most profound thank you goes to Prof. Scherer who gave me the possibility to write my
PhD thesis at the institute he is heading. It was a pleasure for me to work in my project under
his excellent supervision. I also want to thank him for having dedicated so much of his time to
me, especially for discussions, which I really enjoyed and which encouraged me a lot during
my work. I have learnt so much from him.
I am very grateful to Prof. Dieter Naumann from the Robert Koch Institute, Berlin, and his co-
worker Maren Stämmler for introducing me to the FTIR spectroscopy method. I especially
thank Prof. Naumann for his helpful suggestions regarding my project and for accepting the
co-chair of the examination committee. This really honours me.
I would like to thank the “Vereinigung der Förderer und Freunde des Forschungszentrums für
Milch und Lebensmittel Weihenstephan e.V.” for their financial support throughout my work.
My project was supported, in part, by the FEI (Forschungskreis der Ernährungsindustrie e. V.,
Bonn), the AiF (Arbeitskreis für industrielle Forschung) and the German Ministry of
Economics and Technology.
TMI thank Dr. Jürgen Schmitt for kindly introducing me to the NeuroDeveloper software and
for assisting me in designing the ANN.
Special thanks goes to Gertrud Huit and Angela Felsl for supplying me with strains from the
Weihenstephan collection and to those who kindly provided me their
collections especially Prof. H. Hof from Mannheim.
The constructive critics of Dr. H. Seiler and the helpful assistance of Lisa Rieder were greatly
appreciated.
I would like to thank Dr. Mareike Wenning for our interesting scientific discussions and the
FTIR group for the pleasant atmosphere in the lab.
I thank all my colleagues at the institute for the nice working atmosphere and for the kind
moments during the time of my work at the institute.
Thanks goes to Dr. Alejandra Bosch and Prof. Dr. Osvaldo Yantorno for their support from
the other site of the ocean.
I would like to thank my husband Michael Scheer for his immense support and
encouragement all the time. I thank my parents for their constant encouragement throughout
my life.
II
The present thesis is based on the following reviewed and accepted for publication papers or
submitted manuscripts.
Rebuffo-Scheer, C. A., J. Dietrich, M. Wenning and S. Scherer. 2007. Identification of
five Listeria species based on infrared spectra (FTIR) using macro-samples is superior over a
micro-sample approach.
This paper represents chapter 2 of this thesis and has been submitted for publication. The
major part of the experimental work was perfomed or supervised by myself. Jochen Dietrich
carried out part of the experimental work. I wrote the major part of the publication.
Rebuffo, C. A., J. Schmitt, M. Wenning, F. von Stetten, and S. Scherer. 2006. Reliable
and Rapid Identification of Listeria monocytogenes and Listeria Species by Artificial Neural
Network-Based Fourier Transform Infrared Spectroscopy. Appl. Environ. Microbiol.
72:994-1000.
This paper represents chapter 3 of this thesis and constitutes the core of my research. It has
been published in Applied Environmental Microbiology, a Journal of the American Society
for Microbiology (ASM). The major part of the experimental work was performed and
supervised by myself while Felix von Stetten sequenciated the strains and Jürgen Schmitt
assisted me designing the ANN. I wrote the main part of the publication.
Rebuffo-Scheer, C. A., J. Schmitt, and S. Scherer. 2007. Differentiation of Listeria
monocytogenes Serovars by using Artificial Neural Network Analysis of Fourier-Transformed
Infrared Spectra. Appl. Environ. Microbiol. 73:1036-1040.
This paper represents chapter 4 of this thesis and has been published in Applied
Environmental Microbiology, a journal of the ASM. I carried out the experimental work and
wrote the major part of the publication.
III Table of contents
Table of contents
Acknowledgement ................................................................................................................... II
Table of contents.....................................................................................................................IV
Table of Tables..... VII
Table of Figures...................................................................................................................VIII
Symbols and abbreviations....................................................................................................IX
Preface .................................................................................................................................... X
Summary.................................................................................................................................XI
Zusammenfassung...............................................................................................................XIII
1 General Introduction..................................................................................................1
1.1 General characteristics of the genus Listeria................................................................ 1
1.2 Differentiation of Listeria at species level and detection of the human pathogen
L .monocytogenes....................................................................................................................... 1
1.3 Serovars of Listeria....................................................................................................... 4
1.4 Serovar differentiation of L. monocytogenes strains .................................................... 5
1.5 FTIR spectroscopy of microorganisms......................................................................... 6
1.6 Methods of analysis of the FTIR data of microorganisms............................................ 7
Aim and achievement of the work ........................................................................................ 10
2 Identification of five Listeria species based on infrared spectra (FTIR) using
macro-samples is superior over a micro-sample approach .................................. 12
2.1 Summary..................................................................................................................... 12
2.2 Introduction................................................................................................................. 12
2.3 Materials and methods................................................................................................14
2.3.1 Bacterial strains.......................................................................................................... 14
2.3.2 Sample preparation and growth conditions ................................................................ 15
IV Table of contents
2.3.3 Recording of spectra and data evaluation................................................................... 15
2.3.4 Heterogeneity of the microcolonies............................................................................ 16
2.3.5 Variation of the number of strains per species in the library...................................... 16
2.4 Results and discussion................................................................................................17
2.5 Conclusions................................................................................................................. 25
2.6 Acknowledgement......................................................................................................25
3 Reliable and Rapid Identification of Listeria monocytogenes and Listeria Species
by Artificial Neural Network-Based Fourier Transform Infrared Spectroscopy
.................................................................................................................................... 26
3.1 Summary..................................................................................................................... 26