Glycopeptide-resistance transferability from vancomycin-resistant enterococci of human and animal source to Listeria spp.
OBJECTIVE
The glycopeptide-resistance transferability from vancomycin-resistant enterococci (VRE) of clinical and animal origin to different species of Listeria was investigated.


RESULTS
Of 36 matings, performed on membrane filter, the glycopeptide resistance was successfully transferred in six attempts, five with donors of animal origin and only one with donors from clinical source. The acquired glycopeptide resistance in Listeria transconjugants was confirmed by the presence of the conjugative plasmid band and by the amplification of the 732-bp fragment of vanA gene in transferred plasmids.


CONCLUSIONS
Despite the lower number of bacteria used in this study, the source of enterococci influenced the outcome of mating. Moreover transferred VanA plasmid induced a different expression in Listeria transconjugants, suggesting that gene expression might be influenced by species affiliation of recipients.


CONCLUSIONS
Our data strengthen the opinion that enterococci are an important source of resistance genes for Listeria via the transfer of movable genetic elements. As these strains are commonly found in the same habitats, a horizontal spread of glycopeptide resistance in Listeria spp. could be possible.
de Niederhäusern
S
S
Department of Biomedical Sciences, University of Modena and Reggio E., Modena, Italy.
Sabia
C
C
Messi
P
P
Guerrieri
E
E
Manicardi
G
G
Bondi
M
M
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics; D019729:Carbon-Oxygen Ligases / Q000235:genetics; D003227:Conjugation, Genetic; D004269:DNA, Bacterial / Q000032:analysis; D016983:Enterococcus / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D015964:Gene Expression Regulation, Bacterial; D022761:Gene Transfer, Horizontal; D016908:Gram-Positive Bacterial Infections / Q000382:microbiology; D006801:Humans; D008087:Listeria / Q000187:drug effects / Q000235:genetics*; D008826:Microbial Sensitivity Tests; D010957:Plasmids; D017334:Teicoplanin / Q000494:pharmacology; D014640:Vancomycin / Q000494:pharmacology; D020713:Vancomycin Resistance / Q000235:genetics*
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004269:DNA, Bacterial; C071437:VanA ligase, Bacteria; D017334:Teicoplanin; D014640:Vancomycin; D019729:Carbon-Oxygen Ligases