Article

Removal of Antibiotic Resistance Gene-Carrying Plasmids from Lactobacillus reuteri ATCC 55730 and Characterization of the Resulting Daughter Strain, L. reuteri DSM 17938

Department of Microbiology, Swedish University of Agricultural Sciences, PO Box 7025, SE-750 07 Uppsala, Sweden.
Applied and Environmental Microbiology (Impact Factor: 3.67). 09/2008; 74(19):6032-40. DOI: 10.1128/AEM.00991-08
Source: PubMed

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 β-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 β-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 β-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.

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Available from: Stefan Roos, Sep 02, 2015
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    • "L. reuteri ATCC 55730 is a commercially available probiotic strain which has been found to carry potentially transferable resistance traits for tetracycline and lincomycin. Therefore, it has been replaced by L. reuteri DSM 17938, a strain where the two resistance plasmids have been removed without losing any probiotic characteristics[42]. Probiotic strains must be able to resist any adverse conditions encountered during industrial production in order to survive[43]. "

    Full-text · Dataset · Jan 2016
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    • "Three different L. reuteri strains (DSM 20016, ATCC 53608 and SD 2112) were chosen and bioinformatic tools were used (i.e. Kegg pathways, Artemis, Clustal W) to compare them at a genomic level based on the sequencing and annotation data (Rosander et al., 2008; Frese et al., 2011). The aim was to compare the selected strains from the genomic and phenotypic points of view in order to try to explain the differences in metabolic behavior, particularly glucose metabolism through EMP and PKP. "
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    ABSTRACT: The aims of this study is to compare the growth and glucose metabolism of three Lactobacillus reuteri strains (i.e. DSM 20016, DSM 17938, and ATCC 53608) which are lactic acid bacteria of interest used for diverse applications such as probiotics implying the production of biomass, or for the production of valuable chemicals (3-hydroxypropionaldehyde, 3-hydroxypropionic acid, 1,3-propanediol). However, the physiological diversity inside the species, even for basic metabolisms, like its capacity of acidification or glucose metabolism, has not been studied yet. In the present work, the growth and metabolism of three strains representative of the species diversity have been studied in batch mode. The strains were compared through characterization of growth kinetics and evaluation of acidification kinetics, substrate consumption and product formation. The results showed significant differences between the three strains which may be explained, at least in part, by variations in the distribution of carbon source between two glycolytic pathways during the bacterial growth: the phosphoketolase or heterolactic pathway (PKP) and the Embden-Meyerhof pathway (EMP). It was also shown that, in the context of obtaining a large amount of biomass, DSM 20016 and DSM 17938 strains were the most effective in terms of growth kinetics. The DSM 17938 strain, which shows the more significant metabolic shift from EMP to PKP when the pH decreases, is more effective for lactate production.
    Full-text · Article · Oct 2015 · The Journal of Microbiology
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    • "For instance, L. reuteri ATCC 55730, a commercially available probiotic strain, was demonstrated to carry potentially transferable resistance traits for tetracycline and lincomycin. However it has been replaced by L. reuteri DSM 17938, in which the two resistance plasmids have been removed without losing any probiotic characteristics[70]. At the same time, the taxonomy of several LAB has been reconstructed during the last decade, and the use of modern polyphasic taxonomy has reclassified several probiotic strains[6,49,71]. "
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    ABSTRACT: As the resistance of pathogens to antibiotics and the possibility of antibiotic residues in animal products attract increasing attention, the interest in the use of alternatives to in-feed antibiotics has been growing. Recent research with Lactic acid bacteria (LAB) in pigs suggests that LAB provide a potential alternative to antibiotic strategies. LAB include Lactobacillus species, Bifidobacterium spp, Bacillus spp, and some other microbes. LAB can adjust the intestinal environment, inhibit or kill pathogens in the gastrointestinal tract and improve the microbial balance in the intestine, as well as regulate intestinal mucosal immunity and maintain intestinal barrier function, thereby benefiting the health of pigs. The related mechanisms for these effects of LAB may include producing microbicidal substances with effects against gastrointestinal pathogens and other harmful microbes, competing with pathogens for binding sites on the intestinal epithelial cell surface and mucin as well as stimulating the immune system. In this review, the characteristics of LAB and their probiotic effects in newborn piglets, weaned piglets, growing pigs and sows are documented.
    Full-text · Article · Mar 2015 · Pathogens
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