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The sensitivity of periprosthetic tissue culture is inadequate for the diagnosis of prosthetic joint infection (PJI). We investigated and compared the values of sonication fluid culture and periprosthetic tissue culture for diagnosing PJI.Included were patients whose joint prosthesis had been removed for any reason. The resulting sonication fluid and periprosthetic tissues were cultured for 14 days.Of 231 explanted prostheses, aseptic failure was diagnosed in 162 cases (70%) and PJI in 69 (30%). In PJI cases, sonication fluid culture detected 62 microorganisms and periprosthetic tissue culture detected 45. Tissue and sonication fluid cultures showed sensitivities of 61% and 81%, respectively (p0.01), with specificity of 100% and 99%, respectively. On day 1, tissue and sonication fluid cultures were positive in 13% and 28% (p = 0.013) of PJI cases respectively, and on day 2, in 26% and 48% (p = 0.002) of cases. Four anaerobes grew in sonication fluid culture after 7-13 days incubation, whereas tissue culture missed 3 of these. Prolonged incubation of sonication fluid did not detect any organisms in the cases of aseptic failure.Sonication fluid culture provides a more rapid diagnosis and detects about 30% more pathogens, although anaerobic organisms require up to 2 weeks of incubation.

To analyze the characteristics of infection, adequacy of empirical treatment and outcome of patients with community-onset healthcare-associated (HCA) urinary tract infections (UTI) and compare them with hospital (HA) and community-acquired (CA) UTI.Prospective observational cohort study performed at a university 600-bed hospital between July 2009 and February 2010. Patients with UTI requiring hospital admission were included. Epidemiological, clinical and outcome data were recorded.251 patients were included. Patients with community-onset HCA UTI were older, had more co-morbidities and had received previous antimicrobial treatment more frequently than CA UTI (p = 0.02, p = 0.01 and p0.01). ESBL-Escherichia coli and Pseudomonas aeruginosa infections were more frequent in HCA than in CA UTI (p = 0.03 and p0.01). Inadequate empirical treatment was not significantly different between community-onset HCA and CA. Factors related to mortality were P. aeruginosa infection (OR 6.51; 95%CI: 1.01-41.73), diabetes mellitus (OR 22.66; 95%CI: 3.61-142.21), solid neoplasia (OR 22.48; 95%CI: 3.38-149.49) and age (OR 1.15; 95%CI 1.03-1.28).Epidemiological, clinical and microbiological features suggest that community-onset HCA UTI is different from CA and similar to HA UTI. However, in our series inadequate empirical antimicrobial therapy and mortality were not significantly higher in community-onset HCA than in CA UTI.