title: Antibiotic resistant enterococci-tales of a drug resistance gene trafficker.
abstract: Enterococci have been recognized as important hospital-acquired pathogens in recent years, and isolates of E. faecalis and E. faecium are the third- to fourth-most prevalent nosocomial pathogen worldwide. Acquired resistances, especially against penicilin/ampicillin, aminoglycosides (high-level) and glycopeptides are therapeutically important and reported in increasing numbers. On the other hand, isolates of E. faecalis and E. faecium are commensals of the intestines of humans, many vertebrate and invertebrate animals and may also constitute an active part of the plant flora. Certain enterococcal isolates are used as starter cultures or supplements in food fermentation and food preservation. Due to their preferred intestinal habitat, their wide occurrence, robustness and ease of cultivation, enterococci are used as indicators for fecal pollution assessing hygiene standards for fresh- and bathing water and they serve as important key indicator bacteria for various veterinary and human resistance surveillance systems. Enterococci are widely prevalent and genetically capable of acquiring, conserving and disseminating genetic traits including resistance determinants among enterococci and related Gram-positive bacteria. In the present review we aimed at summarizing recent advances in the current understanding of the population biology of enterococci, the role mobile genetic elements including plasmids play in shaping the population structure and spreading resistance. We explain how these elements could be classified and discuss mechanisms of plasmid transfer and regulation and the role and cross-talk of enterococcal isolates from food and food animals to humans.
authors.affiliation: National Reference Centre for Stapyhlococci and Enterococci, Division of Nosocomial Pathogens and Antibiotic Resistances, Robert Koch Institute, Wernigerode Branch, Burgstr. 37, 38855 Wernigerode, Germany. wernerg@rki.de
authors.forename: Guido
authors.initials: G
authors.lastname: Werner
authors.forename: Teresa M
authors.initials: TM
authors.lastname: Coque
authors.forename: Charles M A P
authors.initials: CM
authors.lastname: Franz
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Grohmann
authors.forename: Kristin
authors.initials: K
authors.lastname: Hegstad
authors.forename: Lars
authors.initials: L
authors.lastname: Jensen
authors.forename: Willem
authors.initials: W
authors.lastname: van Schaik
authors.forename: Keith
authors.initials: K
authors.lastname: Weaver
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology; D024881:Drug Resistance, Bacterial; D013293:Enterococcus faecalis / Q000187:drug effects* / Q000235:genetics*; D016984:Enterococcus faecium / Q000187:drug effects* / Q000235:genetics*; D019143:Evolution, Molecular; D041981:Gastrointestinal Tract / Q000382:microbiology; D005798:Genes, Bacterial; D014644:Genetic Variation; D016908:Gram-Positive Bacterial Infections / Q000453:epidemiology / Q000382:microbiology; D006801:Humans; D020071:Interspersed Repetitive Sequences; D010957:Plasmids
chemical_list: D000900:Anti-Bacterial Agents
keywords: Antibiotic resistance; Enterococci; Mobile genetic elements; Population biology