Efficacy of antibiotic treatment of implant-associated Staphylococcus aureus infections with moxifloxacin, flucloxacillin, rifampin, and combination therapy: an animal study.

The efficacy of antibiotic monotherapy and combination therapy in the treatment of implant-associated infection by Staphylococcus aureus was evaluated in an animal study. The femoral medullary cavity of 66 male Wistar rats was contaminated with S. aureus (ATCC 29213) and a metal device was implanted, of which 61 could be evaluated. Six treatment groups were studied: flucloxacillin, flucloxacillin in combination with rifampin, moxifloxacin, moxifloxacin in combination with rifampin, rifampin, and a control group with aqua. The treatment was applied for 14 days. After euthanasia, the bacterial counts in the periprosthetic bone, the soft tissue, and the implant-associated biofilm were measured. Both antibiotic combination treatments (moxifloxacin plus rifampin and flucloxacillin plus rifampin) achieved a highly significant decrease in microbial counts in the bone and soft tissue and in the biofilm. Mono-antibiotic treatments with either moxifloxacin or flucloxacillin were unable to achieve a significant decrease in microbial counts in bone and soft tissue or the biofilm, whilst rifampin was able to reduce the counts significantly only in the biofilm. Antibiotic resistance was measured in 1/3 of the cases in the rifampin group, whereas no resistance was measured in all other groups. The results show that combinations of both moxifloxacin and flucloxacillin plus rifampin are adequate for the treatment of periprosthetic infections due to infections with S. aureus, whereas monotherapies are not effective or not applicable due to the rapid development of antibiotic resistance. Therefore, moxifloxacin is an effective alternative in combination with rifampin for the treatment of implant-associated infections.

A pilot study to evaluate 3'-deoxy-3'-18F-fluorothymidine pet for initial and early response imaging in mantle cell lymphoma.

UNLABELLED: Mantle cell lymphoma (MCL) is a B-cell non-Hodgkin lymphoma. Proliferation activity is considered an important prognostic marker. Immunohistochemical analysis from core biopsy or lymph node may not represent the proliferation rate. We investigated the in vivo proliferation marker 3'-deoxy-3'-(18)F-fluorothymidine ((18)F-FLT) to characterize MCL. METHODS: Eight untreated MCL patients were recruited prospectively. (18)F-FLT PET/CT was performed 45 min after injection of (18)F-FLT. (18)F-FDG PET/CT served as reference. Mean (18)F-FLT standardized uptake values were assessed per lesion and compared with respective (18)F-FDG uptake. Correlation of mean (18)F-FLT and (18)F-FDG uptake in the hottest lesion to Ki67 immunostaining was performed. Five patients underwent repetitive early (18)F-FLT PET. RESULTS: All lymphoma lesions identified by (18)F-FDG PET/CT showed increased (18)F-FLT uptake. Semiquantitative analysis revealed a high mean (18)F-FLT standardized uptake value of 9.9 (range, 5.5-15.9). Mean (18)F-FLT uptake and Ki67 expressions showed a strong positive correlation. CONCLUSION: PET using (18)F-FLT as a biomarker for proliferative activity showed a high sensitivity for MCL. (18)F-FLT uptake shows a correlation with proliferation. Our results warrant further analysis of (18)F-FLT PET in MCL.