Dalbavancin treatment of prosthetic knee infection due to oxacillin-resistant Staphylococcus epidermidis

Infections associated with prosthetic joints are a serious health problem which require multi-disciplinary surgical and medical management. The situation may be complex in the case of allergy, resistance or contraindications to commonly used antibiotics if there are no alternatives. Dalbavancin may be an option but up until now no cases of prosthetic infection treated with this antibiotic have been published, according to the PubMed (years 2000–2017) database with key search words of: dalbavancin and prosthesis. A late reported case of prosthetic infection caused by Staphylococcus epidermidis and treated with dalbavancin is described.

We report the case of a woman aged 55 with a history of chronic kidney disease, short bowel syndrome, the carrier of a central venous catheter for total parenteral long-term nutrition and who had a knee arthroplasty in 2009. After 7 years she presented with signs of prosthetic knee infection. Complete removal of the prosthetic knee and the implantation of a spacer impregnated with vancomycin and gentamicin was carried out. In the samples obtained during the procedure S. epidermidis was isolated, with the minimum inhibitory concentration (MIC) for each antibiotic as described below: vancomycin sensitive (MIC ≤ 1), daptomycin (MIC ≤ 0.5) and linezolid (MIC ≤ 1); resistant to cotrimoxazol (MIC > 2/38), clindamycin (MIC > 2), oxacillin (MIC > 4) and levofloxacin (MIC > 4). Due to the chronic kidney disease, we believed it correct not to use vancomycin, and a treatment with daptomycin in monotherapy was selected for 10 days. When the moment for sequential therapy was reached, the oral alternative with elevated bioavailability was linezolid, which was not used as its complete absorption could not be ensured due to the short bowel syndrome. In order to protect the catheter required for parenteral nutrition and avoid a prolonged hospital stay, outpatient treatment with dalbavancin was administered when its sensitivity by ETEST^® (MIC ≤ 0.047) was made known and in accordance with the recommendations from the Spanish Medicine Agency.¹ A first dose of 1000 mg iv was administered followed by a weekly dose of 500 mg iv for 3 weeks. Two months after becoming asymptomatic and with no signs of infection or organ failure, reimplantation was carried out with continuation of empirical antibiotic treatment until negative obtainment of a total of 5 intraoperative cultures was made from the bone-prosthesis interphase, spacer and synovial fluid. Nine months after follow-up the patient continues in complete remission.

Infection associated with prostheses is one of the most serious complications of arthroplasty. The estimated rate of infection for knee arthoplasties in our environment is between 2% and 3%, with the staphylococcus bacteria being responsible for around 65% of cases.^2,3 Combined therapy based on the extraction of prosthetic material, together with antimicrobial treatment obtains healing rates of around 80%.⁴ Dalbavancin is a parenteral antibiotic of the lipoglycopeptide group, with good action and penetrability in tissue compartments and demonstrates good bacterial activity compared with the majority of gram positive organisms.⁵ The susceptibility of dalbavancin compared with negative coagulase staphylococcus is around 100%.⁶ Dalbavancin has been assessed in vitro, with acceptable results in biofilms generated by staphylococcal infections, although there not enough evidence with regard to prosthetic joint material.^7,8

In our case, with regard to dosing, the recognised recommendations used for treatment of acute skin and soft tissue infection in adult patients were used. This is the only indication which has been approved up until now.⁹ Unlike other antimicrobials where association with rifampicin has proven to be effective, its use in combined therapy does not appear to have been confirmed by the available scientific data which has supported it up until now, and for this reason monotherapy was chosen as therapy.⁷

To conclude, and as a result of this experience, dalbavancin could be used as an alternative in the treatment of oseoarticular infections caused by gram positive bacteria in the event of no other efficacious antimicrobial alternatives existing.