Linezolid alone and in combination with rifampicin prevents experimental vascular graft infection due to methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis.
ABSTRACT In this report we describe the in vivo antibacterial activity of linezolid in an experimental graft infection model in rats and compare it with teicoplanin. The objective of this study was also to determine the effects of the interaction of linezolid when it was combined with rifampicin and test this effect against strains of methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis.
Graft infections were established in the subcutaneous tissue of 130 Wistar rats by implantation of Dacron grafts followed by a topical inoculation with 2 x 10(7) CFU of clinical isolates of MRSA and MRSE. The study included a control group and six groups for each of the staphylococcal strains: an inoculated group that did not receive any antibiotic prophylaxis, two inoculated groups that received intraperitoneal prophylaxis with teicoplanin or linezolid alone, an inoculated group that received rifampicin-soaked grafts, and two inoculated groups that received a combination prophylaxis consisting of intraperitoneal teicoplanin or linezolid and rifampicin-soaked grafts.
There was a reduction in the quantitative bacterial graft cultures in all prophylaxis groups when compared with inoculated control groups. There was not a statistically significant difference between linezolid and teicoplanin prophylaxis groups. The best results were obtained by a combination of rifampicin-soaked grafts with linezolid or teicoplanin.
We found no evidence to suggest that linezolid differs from teicoplanin regarding effectiveness in the prevention of prosthetic vascular graft infection. Linezolid plus rifampicin and teicoplanin plus rifampicin are demonstrated to be valuable prophylactic regimens.
Conference Paper: A unified approach to adaptive nonlinear control of stepper motors[Show abstract] [Hide abstract]
ABSTRACT: In this paper, a robust adaptive nonlinear controller for various types of stepper motors is presented. The control design is applicable to both variable reluctance and permanent magnet stepper motors. It is also shown that the methodology is applicable to other peculiar configurations of stepper motors (e.g. Sawyer motors). Furthermore, the motors may be either rotary or linear. To this end, a general electromechanical model of stepper motors is utilized. The model is comprised of the mechanical dynamics and electrical dynamics of the motor including the effects of cogging, viscous friction, winding resistance or other uncertainties. The robust adaptive design is based on our earlier work (1997) and does utilizes backstepping in the case that voltage level control is used rather than current controls. Simulation studies are presented to show the efficacy of the control design approachDecision and Control, 1997., Proceedings of the 36th IEEE Conference on; 01/1998
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ABSTRACT: Rifampin monotherapy was compared to the combination of linezolid or vancomycin with rifampin in an experimental rat model of methicillin-resistant Staphylococcus aureus (MRSA) chronic foreign body osteomyelitis. MRSA was inoculated into the proximal tibia, and a titanium wire was implanted. Four weeks after infection, rats were treated intraperitoneally for 21 days with rifampin alone (n = 16), linezolid plus rifampin (n = 14), or vancomycin plus rifampin (n = 13). Thirteen animals received no treatment. At completion of treatment, qualitative cultures of the wire and quantitative cultures of the bone (reported as median values) were performed. Quantitative cultures from the control, rifampin monotherapy, linezolid-plus-rifampin, and vancomycin-plus-rifampin groups revealed 4.54, 0.71, 0.10, and 0.50 log₁₀ CFU/gram of bone, respectively. The bacterial load was significantly reduced in all treatment groups compared to that in the control group. Rifampin resistance was detected in isolates from 10, 2, and 1 animal in the rifampin, linezolid-plus-rifampin, and vancomycin-plus-rifampin groups, respectively. Cultures of the removed wire revealed bacterial growth in 1 and 2 animals in the rifampin and linezolid-plus-rifampin groups, respectively, with no growth in the vancomycin-plus-rifampin group and growth from all wires in the untreated group. In conclusion, we demonstrated that combination treatment with linezolid plus rifampin or vancomycin plus rifampin is effective in an animal model of MRSA foreign body osteomyelitis in the context of retention of the infected foreign body.Antimicrobial Agents and Chemotherapy 12/2010; 55(3):1182-6. · 4.57 Impact Factor
Article: Infektionen von Gefäßprothesen[Show abstract] [Hide abstract]
ABSTRACT: Infektionen von Gefäßprothesen sind schwerwiegende Komplikationen von rekonstruktiven gefäßchirurgischen Eingriffen mit hoher konsekutiver Amputationsrate und Letalität. Ihre Pathogenese ist multifaktoriell, und dementsprechend existieren verschiedenste prophylaktische Ansätze. Neben den Grundsätzen der chirurgischen Asepsis werden zusätzliche Maßnahmen zur Verbesserung der hygienischen Bedingungen in der perioperativen Phase angewandt. Die perioperative Antibiotikaprophylaxe ist in diesem Zusammenhang das einzige Mittel, das einen gewissen Evidenzgrad in Bezug auf die Senkung der Rate von Protheseninfekten erreicht hat. Modifikationen von Prothesen zur Steigerung ihrer Infektresistenz z. B. durch Rifampicin- oder Silberbindung sind seit Langem in Gebrauch, die Datenlage hierfür ist allerdings nicht eindeutig und Gegenstand weiterer Untersuchungen. Ähnliches gilt für die lokale Antibiotikaapplikation z. B. in Form von Gentamicin-Kollagen-Schwämmen. Neue Technologien und antimikrobielle Substanzen werden hier in Zukunft möglicherweise einmal die komplett infektresistente Prothese schaffen.Gefässchirurgie 17(1). · 0.24 Impact Factor