Weak effect of metal type and ica genes on staphylococcal infection of titanium and stainless steel implants

Abstract

Currently, ica is considered to be the major operon responsible for staphylococcal biofilm. The effect of biofilm on susceptibility to staphylococcal infection of different implant materials in vivo is unclear. The interaction of ica-positive (wild-type (WT)) and ica-negative (ica(-)) Staphylococcus aureus and Staphylococcus epidermidis strains with titanium and both smooth and rough stainless steel surfaces was studied by scanning electron microscopy in vitro and in a mouse tissue cage model during 2 weeks following perioperative or postoperative inoculation in vivo. In vitro, WT S. epidermidis adhered equally and more strongly than did WT S. aureus to all materials. Both WT strains, but not ica(-) strains, showed multilayered biofilm. In vivo, 300 CFUs of WT and ica(-)S. aureus led, in all metal cages, to an infection with a high level of planktonic CFUs and only 0.89% adherent CFUs after 8 days. In contrast, 10(6) CFUs of the WT and ica(-) strains were required for postoperative infection with S. epidermidis. In all metal types, planktonic numbers of S. epidermidis dropped to <100 WT, and adherent CFUs were low in WT-infected cages and absent in ica(-)-infected cages after 14 days. Perioperative S. epidermidis inoculation resulted in slower clearance than postoperative inoculation, and in titanium cages adherent WT bacteria survived in higher numbers than ica(-) bacteria. In conclusion, the metal played a minor role in susceptibility to and persistence of staphylococcal infection; the presence of ica genes had a strong effect on biofilm in vitro and a weak effect in vivo; and S. epidermidis was more pathogenic when introduced during implantation than after implantation.

Silver Coordination Polymers for Prevention of Implant Infection: Thiol Interaction, Impact on Respiratory Chain Enzymes, and Hydroxyl Radical Induction

“…Therefore, we selected compound 1 to study deposition on implant materials. Rough and smooth titanium (19), as well as steel, which are both utilized in implants, were used as substrates for the deposition of compound 1. In addition, compound 1 was deposited on oriented gold monolayer Au(III) on glass as a smoother model surface.…”

“…epidermidis biofilm-associated infection has been studied using multiple models, most frequently by subcutaneous inser- (19). The bacteria consist of a floating population in the tissue cage fluid and an adherent population in the biofilm, the former being fed by the turnover of the latter.…”

Titanium and steel fracture fixation plates with different surface topographies: Influence on infection rate in a rabbit fracture model

“…In vitro studies show that increasing surface roughness can increase bacterial adhesion, with polished TAN surfaces displaying lower adhesion than standard microrough TAN [6]. Hudetz et al have shown that titanium offers at most a minor improvement in infection risk in an in vivo model, although the subcutaneous implant does not bear close consideration for fracture care implants [22]. Few clinical studies have compared titanium and EPSS implants in humans.…”

Comparison of various surgical methods in the treatment of implant-related infection

“…S. aureus is known to secrete a number of surfaceassociated proteins that are potent stimulators of bone resorption [4]. S. aureus is also capable of producing a protective exopolysaccharide biofilm which plays a major role in infection especially with respect to treatment, even though its role in the development of infection is weak [5]. The use of local antibiotic delivery systems, especially antibiotic-loaded bone cement, is a well established procedure in the treatment of musculoskeletal infections [6][7][8][9][10][11].…”