Increased rate of enteric bacteria as cause of periprosthetic joint infections in patients with liver cirrhosis.

INTRODUCTION: Periprosthetic joint infections (PJI) are a major complication in joint-arthroplasty. Rifampicin is often used as an additional agent to treat PJI, because it penetrates bacterial biofilms. However, rifaximin, belonging to the same antibiotic class as rifampicin, is frequently used to prevent episodes of hepatic encephalopathy in patients with cirrhosis and may induce resistance to rifampicin. The aim of this study was to examine the microbial pattern of periprosthetic joint infections in cirrhotic patients and to test the hypothesis that intake of rifaximin increases the rate of resistance to rifampicin in periprosthetic joint infections. METHODS: A cohort of cirrhotic patients and PJI (n = 25) was analysed on the characteristics of bacterial isolates from sonication and tissue analysis. In a second step a subgroup analysis on the development of rifampicin resistant bacterial specimens, depending on the intake of rifaximin (8 rifaximin intake patients vs. 13 non rifaximin intake patients) was performed. RESULTS: Intestinal bacteria were found in 50% of the specimens, which was significantly more frequent than in a control cohort. By comparison of the single bacterial isolates, rifampicin resistance was detected in 69.2% (9/13) of the rifaximin-intake samples. In contrast, the non-rifaximin-intake isolates only were resistant to rifampicin in 22.2% (4/18) of the cases (p = 0.01). The odds ratio for developing a rifampicin-resistance through rifaximin intake was calculated as OR = 13.5. CONCLUSION: Periprosthetic joint infections have a high incidence of being caused by enteric bacteria in cirrhotic patients. Due to this change in microbial pattern and the innate resistance to rifampicin of most of gram-negative bacteria, the therapy with rifampicin should be carefully considered. The association between the use of rifaximin and developed resistance to rifampicin has a major impact on the treatment of PJI.

Suppression of CMV Infection with Letermovir in a Kidney Transplant Patient.

Infection with cytomegalovirus (CMV) with resistance to ganciclovir (GCV) is a therapeutic challenge in kidney transplant patients, because standard treatment options are nephrotoxic. We report the case of a kidney transplant recipient with GCV-resistant CMV disease, in whom letermovir, a novel inhibitor of CMV packaging, was administered off-label and prevented a relapse of disease once the CMV load was decreased by cidofovir. Furthermore, we observed significant drug interactions between letermovir and tacrolimus. LEARNING POINTS: Cytomegalovirus (CMV) disease with resistance to ganciclovir (GCV) is difficult to manage in transplant patients.Letermovir may become a new option for treatment and prophylaxis of GCV-resistant CMV infection, but assessment of treatment response is difficult.Letermovir may lead to drug interactions via CYP3A4.