In vitro adherence and accumulation of Staphylococcus epidermidis RP 62 A and Staphylococcus epidermidis M7 on four different bone cements

Abstract

Bacterial resistance of Staphylococcus epidermidis, a serious pathogen of implant-related infections, to antibiotics is related to the production of a glycocalyx slime that impairs antibiotic access and the killing by host defense mechanisms. In vitro studies of different bone cements containing antibiotics, developed for the prevention of biomaterial-associated infection, could not always demonstrate complete eradication of biomaterial-adherent bacteria. We have investigated four different bone cements in regard to bacterial accumulation of a slime-producing strain RP 62 A and its isogenic mutant M7 lacking the ability to produce exopolysaccharide slime using a bacterial adhesion assay and modified Kirby-Bauer technique. A significant effect of exopolysaccharide production for the accumulation on bone cement could be demonstrated. The gentamicin/clindamycin bone cement was the only tested biomaterial that produced a large zone of bacterial inhibition in the inoculated area adjacent to the biomaterial. The bacterial adhesion was not reduced significantly and there was no correlation between zones of inhibition on blood agar plates and the quantitative adhesion assay. The clinical efficacy of the gentamicin/clindamycin bone cement must be proven in vivo.

Gentamicin‐loaded bone cement with clindamycin or fusidic acid added: Biofilm formation and antibiotic release

“…18 The combination of gentamicin and clindamycin in bone cement has recently been shown to be able to produce larger zones of inhibition against S. epidermidis than bone cements with only gentamicin. 9 Fusidic acid, with its steroid-like structure, is a lipophilic antibiotic that could be applied as a "slime buster." 9 It has good efficacy against staphylococci and bone penetration and has therefore been suggested as a promising agent against bone infections.…”

“…In contrast, the combination of gentamicin and clindamycin in bone cement inhibited growth of Staphylococcus epidermidis, but in an adhesion assay the combination was not significantly more effective than a monotherapy of gentamicin. 9 There are also conflicting studies concerning the amount of antibiotics released when using a combination of drugs. Some reports show a synergistic effect, 10 whereas others show an inhibitory effect.…”

Effectiveness of Combination Use of Antibiotic-Loaded PerOssal® with Spinal Surgery in Patients with Spondylodiscitis

“…The complete removal of all necrotic tissue is essential, as Gram-positive staphylococci especially colonize necrotic tissues, where they produce a biofilm that drastically reduces their susceptibility to antibiotics [12,13] . Local application of antibiotic-loaded carriers has been demonstrated to be a reliable concept for prevention and treatment of chronic osteomyelitis [9] .…”

Antimicrobial efficacy of gentamicin‐loaded acrylic bone cements with fusidic acid or clindamycin added

“…Therefore, we also tested the different bone cements in a simulated prosthesis-related interfacial gap. In previous reports, it was shown 32 that bacteria were able to grow and adhere on antibiotic-loaded bone cement samples with a large volume-to-area ratio. In a more clinically relevant situation, the volume-to-area ratio is very small, however, for which reason we developed our so-called ''interfacial gap'' model, in which the amount of fluid in between the surfaces to be colonized is small.…”