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The use of chromogenic bacteria as coloured substitutes for pathogens: A simple strategy during design and development of a new method for sample pretreatment
Author(s) -
Rossmanith P.,
Frühwirth K.,
Süß B.,
Schopf E.,
Wagner M.
Publication year - 2010
Publication title -
letters in applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.698
H-Index - 110
eISSN - 1472-765X
pISSN - 0266-8254
DOI - 10.1111/j.1472-765x.2009.02751.x
Subject(s) - bacteria , listeria monocytogenes , chromogenic , salmonella enterica , isolation (microbiology) , salmonella , biology , microbiology and biotechnology , serratia marcescens , food science , escherichia coli , chemistry , chromatography , biochemistry , genetics , gene
Aims: In the present study, chromogenic (red) bacteria were used to simulate actual target bacteria during set‐up and optimization of an isolation process of bacteria, designed for food samples. Isolation of bacteria from food in the context of molecular biological detection of food pathogens is a multistep process. Development of such a separation method requires continuous monitoring of the location of the presumable targets in the sample tubes. Therefore, red‐coloured pigmented bacteria were used as substitutes for the actual target bacteria, during the establishment of a new sample preparation technique. Methods and Results: The chromogenic bacteria Micrococcus roseus and Serratia marcescens were confirmed to withstand the physical (e.g. centrifugal forces) and chemical (e.g. lysis buffer composition) conditions required during establishment of the new technique. Furthermore, the suitability of these model bacteria to substitute for the actual target pathogens ( Salmonella enterica subsp . enterica serovar Typhimurium and Listeria monocytogenes ) was assured by testing the physical properties of the model bacteria with respect to the proposed separation methods . Conclusion: Visibility of the pigmented bacteria within the complex sample matrices served to allocate bacterial content during the various steps necessary for finalization of the method protocol. The presumptive bacterial targets can be allocated simply by visualization of their bright red colour silhouetted against the background sample matrix. Significance and Impact of Study: The use of pigmented bacteria as substitutes for actual colourless target bacteria during design and development of a bacterial isolation method is a simple and inexpensive application. It saves a huge amount of time and resources, as the proof of principle of new methods is possible in rapid succession.