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GFP tagging of Brucella melitensis Rev1 allows the identification of vaccinated sheep
Author(s) -
ZabalzaBaranguá Ana,
SanRomán Beatriz,
ChacónDíaz Carlos,
Miguel MaríaJesús,
Muñoz PilarMaría,
Iriarte Maite,
Blasco JoséMaría,
Grilló MaríaJesús
Publication year - 2019
Publication title -
transboundary and emerging diseases
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.392
H-Index - 63
eISSN - 1865-1682
pISSN - 1865-1674
DOI - 10.1111/tbed.13053
Subject(s) - green fluorescent protein , brucella melitensis , virology , biology , virulence , microbiology and biotechnology , vaccination , brucella , brucellosis , gene , genetics
Brucellosis is a worldwide zoonosis causing important economic loss and a public health problem. Small ruminants are the preferred hosts of Brucella melitensis and thus the main source of human infections. Effective control of sheep and goat brucellosis has been achieved in several countries through vaccination with the live‐attenuated B. melitensis Rev1 vaccine. However, Rev1 induces a long‐lasting serological response that hinders the differentiation between infected and vaccinated animals. A Rev1:: gfp strain expressing constitutively the Green Fluorescent Protein ( GFP ) was built by stable insertion of a mini‐Tn 7 ‐ gfp in the glmS‐recG non‐codifying chromosomal region. An associated indirect ELISA ‐ GFP was developed to identify anti‐ GFP antibodies in vaccinated animals. The resulting Rev1:: gfp kept the biological properties of the Rev1 reference strain, including residual virulence and efficacy in mice, and was readily distinguished from Rev1 and other Brucella field strains by direct visualization under ultraviolet illumination, fluorescence microscopy and a multiplex PCR ‐ GFP . The Rev1:: gfp strain did not elicit anti‐ GFP antibodies itself in lambs but when applied in combination with recombinant GFP induced an intense and long‐lasting (>9 months) anti‐ GFP serological response readily detectable by the ELISA ‐ GFP . Overall, our results confirm that Rev1 GFP ‐tagging can be a suitable alternative for identifying vaccinated sheep in infected contexts.