title: Metabolic activity of Staphylococcus epidermidis is high during initial and low during late experimental foreign-body infection.
abstract: Foreign-body infection (FBI) is notoriously resistant to eradication by antibiotic treatment. It is hypothesized that reduced bacterial metabolic activity contributes to this resistance. We examined the metabolic activity of Staphylococcus epidermidis in 204 samples recovered during in vitro foreign-body colonization and in 424 samples recovered during in vivo FBI in a rat model. Metabolic activity was measured by determining the amount of 16S rRNA per genome by quantitative PCR. The initial foreign-body-associated growth proved to be a metabolically active process, both in vitro and in vivo. The initial 16S rRNA content was similar to that observed during in vitro exponential-growth phase. However, during late in vivo FBI, a 114-fold (P << 0.0001) decrease in the 16S rRNA content was observed, indicating that there was markedly decreased metabolic activity. This decreased metabolic activity during late FBI can explain at least in part why such infections are so difficult to eradicate with conventional antibiotic treatment.
authors.affiliation: Infectious Diseases Research Group, Department of Microbiology and Immunology, Rega Institute for Medical Research and Internal Medicine and Infectious Diseases, University Hospital Leuven, Leuven, Belgium. stefaan.vandecasteele@uz.kuleuven.ac.be
authors.forename: Stefaan Johan
authors.initials: SJ
authors.lastname: Vandecasteele
authors.forename: Willy Eduard
authors.initials: WE
authors.lastname: Peetermans
authors.forename: An
authors.initials: A
authors.lastname: Carbonez
authors.forename: Johan
authors.initials: J
authors.lastname: Van Eldere
mesh_terms: D000818:Animals; D002408:Catheters, Indwelling / Q000382:microbiology*; D004195:Disease Models, Animal; D005549:Foreign-Body Reaction / Q000382:microbiology*; D005856:Germ-Free Life; D016133:Polymerase Chain Reaction; D011140:Polyurethanes; D012329:RNA, Bacterial / Q000032:analysis; D012336:RNA, Ribosomal, 16S / Q000032:analysis; D051381:Rats; D011916:Rats, Inbred F344; D013203:Staphylococcal Infections / Q000382:microbiology*; D013212:Staphylococcus epidermidis / Q000235:genetics / Q000378:metabolism*; D013997:Time Factors
chemical_list: D011140:Polyurethanes; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S