Bacteriophage control of vancomycin-resistant enterococci in cattle compost

Authors

  • K. Otawa,

    1. Laboratory of Sustainable Environmental Biology, Graduate School of Agricultural Science, Tohoku University, Osaki, Miyagi, Japan
    Current affiliation:
    1. AKI Institute Co., Ltd, Yamanashi, Japan
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  • Y. Hirakata,

    1. Department of Infection Control and Laboratory Diagnostics, Graduate School of Medicine, Tohoku University, Aoba-ku, Sendai, Japan
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  • M. Kaku,

    1. Department of Infection Control and Laboratory Diagnostics, Graduate School of Medicine, Tohoku University, Aoba-ku, Sendai, Japan
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  • Y. Nakai

    Corresponding author
    • Laboratory of Sustainable Environmental Biology, Graduate School of Agricultural Science, Tohoku University, Osaki, Miyagi, Japan
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Correspondence

Yutaka Nakai, Laboratory of Sustainable Environmental Biology, Graduate School of Agricultural Science, 232-3 Yomogida, Naruko, Osaki, Miyagi 989-6711, Japan. E-mail: nakai@bios.tohoku.ac.jp

Abstract

Aims

To isolate bacteriophage that infects vancomycin-resistant enterococci (VRE) and to investigate the ability of this phage to diminish VRE number in vitro and in experimentally VRE-inoculated compost.

Methods and Results

We sampled 106 solid or water samples, including 101 bovine faecal samples; lytic phage named Vrep-5 was isolated from one bovine faecal sample by plaque assay using the clinical VRE isolate FN1 (Enterococcus faecium). Vrep-5 generated clear plaques 1 mm in diameter and exhibited characteristics of the family Myoviridae A1, with a spherical head (122 ± 16 nm) and a contractile tail (152 ± 17 nm long). Vrep-5 lysed other bacterial strains, including Enterococcus faecalis. Inoculation of vrep-5 into 0·5 g unsterilized compost experimentally inoculated with FN1 at the multiplicity of infection of 1500 (8·8 × 104 CFU g−1 VRE and 1·3 × 108 PFU g−1 vrep-5) led to a decrease of >3 log10 in VRE abundance compared with the untreated control after 24 h of incubation.

Conclusions

The data show that bacteriophage vrep-5 is effective in the rapid reduction in VRE colonization in compost.

Significance and Impact of the Study

The present study gives valuable new knowledge in the fight against VRE in the animal production.

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