Use of the automated ribotyping for epidemiological investigations

In order to understand the epidemiology of food related pathogenic bacteria, such as Salmonella spp. and Listeria monocytogenes, reproducible typing methods, which can distinguish individual strains, different in virulence and host range, are necessary. In comparison with the phenotypic techniques, many molecular typing methods offer the advantages of high discriminating ability and typeability; however a lack of standardisation and the use of different codes, within different laboratories, to identify specific genetic types, restrict their large diffusion. Both these limitations can be easily overcome using an automated technique, such as the RiboPrinter® Microbial Characterisation System (Qualicon, Inc.), which automates and standardises all process steps, from cell lysis to image analysis. In this paper examples of application of the RiboPrinter® to characterise Salmonella enteritidis and Salmonella typhimurium, as well as L. monocytogenes strains, are described. The automated ribotyping analysis seems to provide a useful tool to address the identification of the sources and the transmission routes of these foods related pathogenic bacteria.