Improved aero-anaerobe recovery from infected prosthetic joint samples taken from 72 patients and collected intraoperatively in Rosenow's broth.

INTRODUCTION: Recovery of the bacteria responsible for prosthetic joint infections is a major problem, which is due in part to the alteration of their ability to grow by storage during transportation to the laboratory.
METHODS: In this prospective study, we assessed the benefit of inoculating an enriched liquid medium (Rosenow's broth) with intraoperative samples from 72 patients with prosthetic joint revision due to infection. We compared the results of culture of specimens collected in a standard receptacle with the results for specimens collected in Rosenow's broth. RESULTS AND
INTERPRETATION: 144 samples were taken by each of the 2 collection methods for subsequent culture. Concordance between standard and Rosenow samples was observed for 52 of the 58 strains cultured on agar and for 42 of the 97 strains (p < 0.001) which grew only in liquid medium. Infection would not have been diagnosed in 26 patients (almost one-third of all patients) without combining sample collection in Rosenow's broth with standard collection. The bacteria that were not recovered from standard samples but which were recovered from those collected in Rosenow's broth included not only strict anaerobes, in particular Propionibacterium acnes, but also coagulase-negative staphylococci and streptococci.