Novel lnu(G) gene conferring resistance to lincomycin by nucleotidylation, located on Tn6260 from Enterococcus faecalis E531.
J Antimicrob Chemother
; 72(4): 993-997, 2017 04 01.
Article
em En
| MEDLINE
| ID: mdl-28039271
ABSTRACT
Objectives:
To identify a novel putative lincosamide resistance gene determinant in a swine Enterococcus faecalis E531 exhibiting a lincosamide resistance/macrolide susceptibility (L R M S ) phenotype and to determine its location and genetic environment.Methods:
The whole genomic DNA of E. faecalis E531, which tested negative for the known lincosamide nucleotidyltransferase genes, was sequenced. A putative lincosamide resistance gene determinant was cloned into an Escherichia coli - E. faecalis shuttle vector (pAM401) and transformed into E. faecalis JH2-2. The MICs were determined by the microbroth dilution method. Inactivity of lincomycin was examined by UPLC-MS/MS. Inverse PCR and primer walking were used to explore the genetic environment based on the assembled sequence.Results:
A novel resistance gene, designated lnu (G), which encodes a putative lincosamide nucleotidyltransferase, was found in E. faecalis E531. The deduced Lnu(G) amino acid sequence displayed 76.0% identity to Lnu(B) in Enterococcus faecium . Both E. faecalis E531 and E. faecalis JH2-2 harbouring pAM401- lnu (G) showed a 4-fold increase in the MICs of lincomycin, compared with E. faecalis JH2-2 or E. faecalis JH2-2 harbouring empty vector pAM401 only. UPLC-MS/MS demonstrated that the Lnu(G) enzyme catalysed adenylylation of lincomycin. The genetic environment analysis revealed that the lnu (G) gene was embedded into a novel putative transposon, designated Tn 6260 , which was active.Conclusions:
A novel lincosamide nucleotidyltransferase gene lnu (G) was identified in E. faecalis . The location of the lnu (G) gene on a mobile element Tn 6260 makes it easy to disseminate.
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Elementos de DNA Transponíveis
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Lincomicina
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Enterococcus faecalis
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Farmacorresistência Bacteriana
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Antibacterianos
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Nucleotidiltransferases
Limite:
Animals
Idioma:
En
Revista:
J Antimicrob Chemother
Ano de publicação:
2017
Tipo de documento:
Article