A multiresistance megaplasmid pLG1 bearing a hylEfm genomic island in hospital Enterococcus faecium isolates.
Enterococcus faecium is considered to be a nosocomial pathogen with increasing medical importance. The putative virulence factor, hyl(Efm), encoding a putative hyaluronidase, is enriched among the hospital-associated polyclonal subpopulation of E. faecium.. The hyl(Efm) gene is described to be part of a genomic island and was recently identified to be plasmid-located. Here, we present a description of the structure, localization, and distribution of the putative pathogenicity factor hyl(Efm) and its putative island among 39 clinical isolates and elucidate the composition and host range of pLG1, a hyl(Efm) multiresistance plasmid of approximately 281.02kb. The hyl(Efm) gene was located within a 17,824-bp element highly similar to the putative genomic island (GI) structure that had been previously described. This genomic region was conserved among 39 hyl(Efm)-positive strains with variation in a specific region downstream of hyl(Efm) in 18 strains. The putative hyl(Efm) was located on large plasmids (150-350kb) in 37 strains. pLG1 could be horizontally transferred into four different E. faecium recipient strains (n=4) but not into E. faecalis (n=3). Sequencing of pLG1 resolved putative plasmid replication, conjugation, and maintenance determinants as well as a pilin gene cluster, carbon uptake and utilization genes, heavy metal and antibiotic resistance clusters. The hyl(Efm) transferable plasmid pLG1 bears additional putative pathogenicity factors and antibiotic resistance genes. These findings suggest horizontal gene transfer of virulence factors and antibiotic resistance gene clusters by a single genetic event (conjugative transfer) which might be triggered by heavy antibiotic use common in health care units where E. faecium is increasingly prevalent.
Robert Koch Institute, Infectious Diseases, Wernigerode Branch, Burgstraße 37, D-38855 Wernigerode, Germany.
Jenny A
JA
Laverde Gomez
Willem
W
van Schaik
Ana R
AR
Freitas
Teresa M
TM
Coque
Keith E
KE
Weaver
Maria Victoria
MV
Francia
Wolfgang
W
Witte
Guido
G
Werner
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics; D003227:Conjugation, Genetic; D017124:Conserved Sequence; D003428:Cross Infection / Q000382:microbiology*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D024901:Drug Resistance, Multiple, Bacterial; D013293:Enterococcus faecalis / Q000235:genetics; D016984:Enterococcus faecium / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity*; D022761:Gene Transfer, Horizontal; D044404:Genomic Islands; D016908:Gram-Positive Bacterial Infections / Q000382:microbiology*; D006801:Humans; D008969:Molecular Sequence Data; D010957:Plasmids / Q000032:analysis*; D017422:Sequence Analysis, DNA; D037521:Virulence Factors / Q000235:genetics*
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D037521:Virulence Factors