title: Effect of parenteral antibiotic administration on the establishment of colonization with vancomycin-resistant Enterococcus faecium in the mouse gastrointestinal tract.
abstract: A mouse model of intestinal colonization with vancomycin-resistant enterococci (VRE) was used to study the effect of different beta-lactam antibiotics on establishment of VRE colonization. A clinical VanB VRE isolate, Enterococcus faecium C68 (102 or 104 cfu), was inoculated by gastric gavage in conjunction with subcutaneous administration of antibiotics. The MIC of ceftriaxone and ticarcillin against VRE strain C68 is >10,000 microg/mL, and the MIC of piperacillin is 1250 microg/mL. Ceftriaxone and ticarcillin-clavulanate treatment groups developed persistently high levels of stool VRE compared with both the saline and the piperacillin-tazobactam (Pip-Taz) groups (P<.008). The level of stool VRE in the Pip-Taz group did not differ from that for the saline group. Thus, in this mouse model, beta-lactam antibiotics with minimal anti-enterococcal activity promoted establishment of high-level VRE colonization, but Pip-Taz (a beta-lactam antibiotic with more potent activity against VRE) did not.
authors.affiliation: Division of Infectious Diseases, Louis Stokes Dept. of Veterans Affairs Medical Center, Cleveland, OH 44106. curtisd123@yahoo.com.
authors.forename: C J
authors.initials: CJ
authors.lastname: Donskey
authors.forename: J A
authors.initials: JA
authors.lastname: Hanrahan
authors.forename: R A
authors.initials: RA
authors.lastname: Hutton
authors.forename: L B
authors.initials: LB
authors.lastname: Rice
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D002443:Ceftriaxone / Q000627:therapeutic use; D019818:Clavulanic Acid / Q000627:therapeutic use; D016984:Enterococcus faecium / Q000187:drug effects* / Q000472:pathogenicity / Q000502:physiology*; D005243:Feces / Q000382:microbiology; D005260:Female; D016908:Gram-Positive Bacterial Infections / Q000188:drug therapy*; D006801:Humans; D007263:Infusions, Parenteral; D007413:Intestinal Mucosa / Q000382:microbiology*; D051379:Mice; D008826:Microbial Sensitivity Tests; D013982:Ticarcillin / Q000627:therapeutic use; D020713:Vancomycin Resistance
chemical_list: D000900:Anti-Bacterial Agents; D019818:Clavulanic Acid; D002443:Ceftriaxone; D013982:Ticarcillin