Outbreak of Nontuberculous Mycobacteria Joint Prosthesis Infections, Oregon, USA, 2010-2016.

We investigated a cluster of Mycobacterium fortuitum and M. goodii prosthetic joint surgical site infections occurring during 2010-2014. Cases were defined as culture-positive nontuberculous mycobacteria surgical site infections that had occurred within 1 year of joint replacement surgery performed on or after October 1, 2010. We identified 9 cases by case finding, chart review, interviews, surgical observations, matched case-control study, pulsed-field gel electrophoresis of isolates, and environmental investigation; 6 cases were diagnosed >90 days after surgery. Cases were associated with a surgical instrument vendor representative being in the operating room during surgery; other potential sources were ruled out. A tenth case occurred during 2016. This cluster of infections associated with a vendor reinforces that all personnel entering the operating suite should follow infection control guidelines; samples for mycobacterial culture should be collected early; and postoperative surveillance for <90 days can miss surgical site infections caused by slow-growing organisms requiring specialized cultures, like mycobacteria.

Time trends in the aetiology of prosthetic joint infections: a multicentre cohort study.

It is important to know the spectrum of the microbial aetiology of prosthetic joint infections (PJIs) to guide empiric treatment and establish antimicrobial prophylaxis in joint replacements. There are no available data based on large contemporary patient cohorts. We sought to characterize the causative pathogens of PJIs and to evaluate trends in the microbial aetiology. We hypothesized that the frequency of antimicrobial-resistant organisms in PJIs has increased in the recent years. We performed a cohort study in 19 hospitals in Spain, from 2003 to 2012. For each 2-year period (2003-2004 to 2011-2012), the incidence of microorganisms causing PJIs and multidrug-resistant bacteria was assessed. Temporal trends over the study period were evaluated. We included 2524 consecutive adult patients with a diagnosis of PJI. A microbiological diagnosis was obtained for 2288 cases (90.6%). Staphylococci were the most common cause of infection (1492, 65.2%). However, a statistically significant rising linear trend was observed for the proportion of infections caused by Gram-negative bacilli, mainly due to the increase in the last 2-year period (25% in 2003-2004, 33.3% in 2011-2012; p 0.024 for trend). No particular species contributed disproportionally to this overall increase. The percentage of multidrug-resistant bacteria PJIs increased from 9.3% in 2003-2004 to 15.8% in 2011-2012 (p 0.008), mainly because of the significant rise in multidrug-resistant Gram-negative bacilli (from 5.3% in 2003-2004 to 8.2% in 2011-2012; p 0.032). The observed trends have important implications for the management of PJIs and prophylaxis in joint replacements.

A historical perspective of pacemaker infections: 40-years single-centre experience.

AIMS: The approach to infected cardiac devices has changed during recent decades. Optimal treatment is still a matter of debate, especially in pacemaker-dependent patients. Therefore, we investigated the management and outcome of patients with pacemaker infections in a single centre over four decades. METHODS AND RESULTS: We conducted a retrospective analysis of 4212 patients and extracted those with pacemaker infections admitted to Rostock Heart Center between 1973 and 2012. One hundred and thirty-one consecutive patients (median age 69.6 ± 14.9 years) were admitted for device infections. Two-stage exchange was performed in 42 patients (32.8%). In 72 patients (55%), explantation and implantation on the contralateral side was performed simultaneously. In 17 cases the device was not replaced. Mean follow-up was 63 ± 81 months. Reinfection rate was 12.2%, which declined from 24% (1980s) to 2.6% (after 2000). Complete device removal (in 57.3%) reduced the risk for reinfection by 75% (P = 0.02), as well as increasing age (0.049% per year, P = 0.001). One-stage exchange increased the risk of reinfection six-fold (P = 0.021). Cultured bacteria after initiation of antibiotic therapy predicted a four-fold increase in risk of a recurrent infection (P = 0.01). CONCLUSION: Continuous assimilation of guidelines for pacemaker infection improved the outcome over time: complete extraction of the infected device seems to be highly desirable. A one-stage exchange increased the risk of recurrent device infection and should probably be avoided, but complete extraction seems to be more important than timing.

From Koch's postulates to biofilm theory. The lesson of Bill Costerton.

The clinical diagnoses of implant infections pose insurmountable difficulties for cultural methods because of their frequent failure when bacteria are growing in biofilms. In 1978 Bill Costerton warned that chronic infections in patients with indwelling medical devices were caused by bacteria growing in well-developed glycocalyx-enclosed biofilms and that bacteria within biofilms resist antibiotic therapies and immune host defenses. Costerton's "biofilm theory" opened two lines of scientific endeavor: the study of the biochemistry and genetics of biofilm formation and function; and, on the other side, the search for new methods for medical diagnosis and treatment of biofilm-centered implant infections. This Editorial and the entire 2012 issue "Focus on Implant Infections" are dedicated to the memory of Bill Costerton, recognized worldwide as the Father of Biofilms for his innovation and body of work on infections caused by sessile bacteria. Bill Costerton was a great scientist, heedful both to the biological aspects of biofilms and to the medical challenges of new diagnostic methods and modern therapeutic approaches to implant infections. But, most of all, he was a charming Maestro for the large number of colleagues and students whose enthusiasm for the science he was able to nourish. Bill passed away on May 12th, 2012 and the entire science community mourns the death of a friend and a leader.