76
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      High-throughput genome sequencing of two Listeria monocytogenes clinical isolates during a large foodborne outbreak

      research-article

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Background

          A large, multi-province outbreak of listeriosis associated with ready-to-eat meat products contaminated with Listeria monocytogenes serotype 1/2a occurred in Canada in 2008. Subtyping of outbreak-associated isolates using pulsed-field gel electrophoresis (PFGE) revealed two similar but distinct AscI PFGE patterns. High-throughput pyrosequencing of two L. monocytogenes isolates was used to rapidly provide the genome sequence of the primary outbreak strain and to investigate the extent of genetic diversity associated with a change of a single restriction enzyme fragment during PFGE.

          Results

          The chromosomes were collinear, but differences included 28 single nucleotide polymorphisms (SNPs) and three indels, including a 33 kbp prophage that accounted for the observed difference in AscI PFGE patterns. The distribution of these traits was assessed within further clinical, environmental and food isolates associated with the outbreak, and this comparison indicated that three distinct, but highly related strains may have been involved in this nationwide outbreak. Notably, these two isolates were found to harbor a 50 kbp putative mobile genomic island encoding translocation and efflux functions that has not been observed in other Listeria genomes.

          Conclusions

          High-throughput genome sequencing provided a more detailed real-time assessment of genetic traits characteristic of the outbreak strains than could be achieved with routine subtyping methods. This study confirms that the latest generation of DNA sequencing technologies can be applied during high priority public health events, and laboratories need to prepare for this inevitability and assess how to properly analyze and interpret whole genome sequences in the context of molecular epidemiology.

          Related collections

          Most cited references53

          • Record: found
          • Abstract: not found
          • Article: not found

          Artemis: sequence visualization and annotation

            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            The epidemiology of human listeriosis.

            Listeriosis is a serious invasive disease that primarily afflicts pregnant women, neonates and immunocompromised adults. The causative organism, Listeria monocytogenes, is primarily transmitted to humans through contaminated foods. Outbreaks of listeriosis have been reported in North America, Europe and Japan. Soft cheeses made from raw milk and ready-to-eat meats are high risk foods for susceptible individuals. Efforts by food processors and food regulatory agencies to aggressively control L. monocytogenes in the high risk foods have resulted in significant decreases in the incidence of sporadic listeriosis.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Comparative genomics of Listeria species.

              Listeria monocytogenes is a food-borne pathogen with a high mortality rate that has also emerged as a paradigm for intracellular parasitism. We present and compare the genome sequences of L. monocytogenes (2,944,528 base pairs) and a nonpathogenic species, L. innocua (3,011,209 base pairs). We found a large number of predicted genes encoding surface and secreted proteins, transporters, and transcriptional regulators, consistent with the ability of both species to adapt to diverse environments. The presence of 270 L. monocytogenes and 149 L. innocua strain-specific genes (clustered in 100 and 63 islets, respectively) suggests that virulence in Listeria results from multiple gene acquisition and deletion events.
                Bookmark

                Author and article information

                Journal
                BMC Genomics
                BMC Genomics
                BioMed Central
                1471-2164
                2010
                18 February 2010
                : 11
                : 120
                Affiliations
                [1 ]National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB, Canada
                [2 ]Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB, Canada
                [3 ]Public Health Laboratories, Ontario Agency for Health Protection and Promotion, Toronto, ON, Canada
                [4 ]Canadian Food Inspection Agency, Ottawa, ON, Canada
                Article
                1471-2164-11-120
                10.1186/1471-2164-11-120
                2834635
                20167121
                3c3eec9c-14ca-4a48-b92d-22bef86eacb9
                Copyright ©2010 Gilmour et al; licensee BioMed Central Ltd.

                This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

                History
                : 30 June 2009
                : 18 February 2010
                Categories
                Research Article

                Genetics
                Genetics

                Comments

                Comment on this article