The ubiquitous nature of Listeria monocytogenes clones: a large-scale Multilocus Sequence Typing study

• Published in: Environmental microbiology 2014-02, Vol.16 (2), p.405-416
• Main Authors: Haase, Jana K., Didelot, Xavier, Lecuit, Marc, Korkeala, Hannu, Achtman, Mark
• Format: Article
• Language: English
• Subjects: Animal, plant and microbial ecology; Animals; Bacterial Typing Techniques; Bacteriology; Biological and medical sciences; Environmental Microbiology; Evolution; Food Contamination; Fundamental and applied biological sciences. Psychology; General aspects; Genetic Variation; Genotype; Humans; Listeria; Listeria monocytogenes; Listeria monocytogenes - classification; Listeria monocytogenes - genetics; Listeriosis; Microbial ecology; Microbiology; Miscellaneous; Multilocus Sequence Typing; Phylogeny
• ISSN: 1462-2912; 1462-2920
• DOI: 10.1111/1462-2920.12342

Summary Listeria monocytogenes is ubiquitously prevalent in natural environments and is transmitted via the food chain to animals and humans, in whom it can cause life‐threatening diseases. We used Multilocus Sequence Typing (MLST) of ∼2000 isolates of L. monocytogenes to investigate whether specific associations existed between clonal complexes (CCs) and the environment versus diseased hosts. Most CCs (72%) were not specific for any single source, and many have been isolated from the environment, food products, animals as well as from humans. Our results confirm that the population structure of L. monocytogenes is largely clonal and consists of four lineages (I–IV), three of which contain multiple CCs. Most CCs have remained stable for decades, but one epidemic clone (CC101) was common in the mid‐1950s and very rare until recently when it may have begun to re‐emerge. The historical perspective used here indicates that the central sequence types of CCs were not ancestral founders but have rather simply increased in frequency over decades.