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 Ͻ Ͻ 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.

No need for broad-spectrum empirical antibiotic coverage after surgical drainage of orthopaedic implant infections

“…One theoretical concern of our study relates to retained implants, especially retained arthroplasties. Biofilm formation starts within a very short period of time [7]. If an implant is removed (and therefore the biofilm is removed with the implant), it is conceivable that potentially incorrect antibiotic therapy has no influence on the outcome.…”

“…Many colleagues think that it would be beneficial if empirical antibiotic administration could cover all possible pathogens for arthroplasty [2] and other orthopaedic infections [4], with usual recurrence rates oscillating between 15 and 28 % [2,5,6], and especially in cases of implant retention. Experimentally speaking, biofilms are established within a few hours or days [7], and infections with resistant micro-organisms may harbour more treatment failures than infections due to susceptible bacteria [5]. Therefore it is not surprising that many authors routinely administer vancomycin, alone [3] or in combination with meropenem [2,3], or aminoglycosides [4] or other antipseudomonal drugs [4], until the pathogen is identified.…”

Staphylococcus aureus Infections in Hemodialysis

“…Biofilm formation determines the persistent character of S. aureus foreign body-related infections, endocarditis, and osteoarticular infections. Whereas the metabolism of planktonic staphylococci in sepsis is mainly oriented on rapid dissemination, sessile staphylococci in biofilms behave as organized communities of bacteria with a markedly reduced metabolic activity that are mainly oriented on long-term survival (8,(11)(12)(13)(14)(15). The most notable clinical characteristic of this biofilm-associated sessile growth mode is the persistent nature of the subsequent infection (9,16).…”

Inhibition of Staphylococcus epidermidis Biofilm Formation by Rabbit Polyclonal Antibodies against the SesC Protein

“…Biofilm-associated bacteria have been shown to have low metabolic activity and altered gene expression patterns (28,30). To confirm expression of sesC in sessile and planktonic bacteria, we analyzed gene and protein expression levels.…”

“…Sevenmillimeter fragments of a commercial polyurethane intravenous catheter (Arrow International, Reading, PA) were added, and the mixture was incubated at 37°C. After various incubation periods, RNA and DNA were extracted as described previously (12,28,29,31). Nucleic acid was isolated from bacteria adhering to the catheter fragments and from planktonic bacteria at zero time (n ϭ 8) (just before the bacteria were suspended in 0.9% NaCl) and after 10 min (n ϭ 16), 35 min (n ϭ 16), 60 min (n ϭ 16), 120 min (n ϭ 16), and 180 min (n ϭ 16).…”