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Research article2008Peer reviewedOpen access

Removal of antibiotic resistance gene-carrying plasmids from Lactobacillus reuteri ATCC 55730 and characterization of the resulting daughter strain, L. reuteri DSM 17938

Rosander, Anna; Connolly, Eamonn; Roos, Stefan

Abstract

The spread of antibiotic resistance in pathogens is primarily a consequence of the indiscriminate use of antibiotics, but there is concern that food-borne lactic acid bacteria may act as reservoirs of antibiotic resistance genes when distributed in large doses to the gastrointestinal tract. Lactobacillus reuteri ATCC 55730 is a commercially available probiotic strain which has been found to harbor potentially transferable resistance genes. The aims of this study were to define the location and nature of beta-lactam, tetracycline, and lincosamide resistance determinants and, if they were found to be acquired, attempt to remove them from the strain by methods that do not genetically modify the organism before subsequently testing whether the probiotic characteristics were retained. No known beta-lactam resistance genes was found, but penicillin-binding proteins from ATCC 55730, two additional resistant strains, and three sensitive strains of L. reuteri were sequenced and comparatively analyzed. The beta-lactam resistance in ATCC 55730 is probably caused by a number of alterations in the corresponding genes and can be regarded as not transferable. The strain was found to harbor two plasmids carrying tet(W) tetracycline and lnu(A) lincosamide resistance genes, respectively. A new daughter strain, L. reuteri DSM 17938, was derived from ATCC 55730 by removal of the two plasmids, and it was shown to have lost the resistances associated with them. Direct comparison of the parent and daughter strains for a series of in vitro properties and in a human clinical trial confirmed the retained probiotic properties of the daughter strain.

Published in

Applied and Environmental Microbiology
2008, Volume: 74, number: 19, pages: 6032-6040

      SLU Authors

      • Sustainable Development Goals

      Ensure healthy lives and promote well-being for all at all ages
      End hunger, achieve food security and improved nutrition and promote sustainable agriculture

      UKÄ Subject classification

      Animal and Dairy Science
      Veterinary Science
      Food Science

      Publication identifier

      DOI: https://doi.org/10.1128/AEM.00991-08

      Permanent link to this page (URI)

      https://res.slu.se/id/publ/18986