Genetic investigation within Lactococcus garvieae revealed two genomic lineages

Authors

  • Chiara Ferrario,

    1. Dipartimento di Scienze e Tecnologie Alimentari e Microbiologiche, Sezione di Microbiologia Industriale, Università degli Studi di Milano, Milan, Italy
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  • Giovanni Ricci,

    1. Dipartimento di Scienze e Tecnologie Alimentari e Microbiologiche, Sezione di Microbiologia Industriale, Università degli Studi di Milano, Milan, Italy
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  • Francesca Borgo,

    1. Dipartimento di Scienze e Tecnologie Alimentari e Microbiologiche, Sezione di Microbiologia Industriale, Università degli Studi di Milano, Milan, Italy
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  • Alessandro Rollando,

    1. Dipartimento di Scienze e Tecnologie Alimentari e Microbiologiche, Sezione di Microbiologia Industriale, Università degli Studi di Milano, Milan, Italy
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  • Maria Grazia Fortina

    Corresponding author
    • Dipartimento di Scienze e Tecnologie Alimentari e Microbiologiche, Sezione di Microbiologia Industriale, Università degli Studi di Milano, Milan, Italy
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Correspondence: Maria Grazia Fortina, Dipartimento di Scienze e Tecnologie Alimentari e Microbiologiche, Sezione di Microbiologia Industriale, Università degli Studi di Milano, via Celoria 2, 20133 Milan, Italy. Tel: +39 02 50319131; fax: +39 02 50319191; e-mail: grazia.fortina@unimi.it

Abstract

The diversity of a collection of 49 Lactococcus garvieae strains, including isolates of dairy, fish, meat, vegetable and cereal origin, was explored using a molecular polyphasic approach comprising PCR-ribotyping, REP and RAPD-PCR analyses and a multilocus restriction typing (MLRT) carried out on six partial genes (atpA, tuf, dltA, als, gapC, and galP). This approach allowed high-resolution cluster analysis in which two major groups were distinguishable: one group included dairy isolates, the other group meat isolates. Unexpectedly, of the 12 strains coming from fish, four grouped with dairy isolates, whereas the others with meat isolates. Likewise, strains isolated from vegetables allocated between the two main groups. These findings revealed high variability within the species at both gene and genome levels. The observed genetic heterogeneity among L. garvieae strains was not entirely coherent with the ecological niche of origin of the strains, but rather supports the idea of an early separation of L. garvieae population into two independent genomic lineages.

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