Prognosis of unexpected positive intraoperative cultures in arthroplasty revision: A large multicenter cohort

BACKGROUND

The positive-intraoperative-cultures-type prosthetic joint infection (PIOC-PJI) is considered when surgical cultures yield microorganisms in presumed aseptic arthroplasty revisions. Herein we assess the risk factors for failure in the largest cohort of PIOC-PJI patients reported to date.

METHODS

A retrospective, observational, multicenter study was performed during 2007-2017. Surgeries leading to diagnose PIOC-PJI included only one-stage procedures with either complete or partial prosthesis revision. Failure was defined as recurrence caused by the same microorganism.

RESULTS

203 cases were included (age 72 years, 52% females). Coagulase-negative staphylococci (n = 125, 62%) was the main etiology, but some episodes were caused by virulent bacteria (n = 51, 25%). Prosthesis complete and partial revision was performed in 93 (46%) and 110 (54%) cases, respectively. After a median of 3.4 years, failure occurred in 17 episodes (8.4%, 95%CI 5.3-13.1). Partial revision was an independent predictor of failure (HR 3.63; 95%CI 1.03-12.8), adjusted for gram-negative bacilli (GNB) infection (HR 2.68; 95%CI 0.91-7.89) and chronic renal impairment (HR 2.40; 95%CI 0.90-6.44). Treatment with biofilm-active antibiotics (rifampin/fluoroquinolones) had a favorable impact on infections caused by staphylococci and GNB.

CONCLUSION

Overall prognosis of PIOC-PJI is good, but close follow-up is required in cases of partial revision and in infections caused by GNB.

Role of asymptomatic bacteriuria on early periprosthetic joint infection after hip hemiarthroplasty. BARIFER randomized clinical trial

PURPOSE

To evaluate preoperative asymptomatic bacteriuria (ASB) treatment to reduce early-periprosthetic joint infections (early-PJIs) after hip hemiarthroplasty (HHA) for fracture.

METHODS

Open-label, multicenter RCT comparing fosfomycin-trometamol versus no intervention with a parallel follow-up cohort without ASB.

PRIMARY OUTCOME

early-PJI after HHA.

RESULTS

Five hundred ninety-four patients enrolled (mean age 84.3); 152(25%) with ASB (77 treated with fosfomycin-trometamol/75 controls) and 442(75%) without. Despite the study closed without the intended sample size, ASB was not predictive of early-PJI (OR: 1.06 [95%CI: 0.33-3.38]), and its treatment did not modify early-PJI incidence (OR: 1.03 [95%CI: 0.15-7.10]).

CONCLUSIONS

Neither preoperative ASB nor its treatment appears to be risk factors of early-PJI after HHA. ClinicalTrials.gov Identifier: Eudra CT 2016-001108-47.

The Different Microbial Etiology of Prosthetic Joint Infections according to Route of Acquisition and Time after Prosthesis Implantation, Including the Role of Multidrug-Resistant Organisms

The aim of our study was to characterize the etiology of prosthetic joint infections (PJIs)-including multidrug-resistant organisms (MDRO)-by category of infection. A multicenter study of 2544 patients with PJIs was performed. We analyzed the causative microorganisms according to the Tsukayama's scheme (early postoperative, late chronic, and acute hematogenous infections (EPI, LCI, AHI) and "positive intraoperative cultures" (PIC)). Non-hematogenous PJIs were also evaluated according to time since surgery: <1 month, 2-3 months, 4-12 months, >12 months. AHIs were mostly caused by Staphylococcus aureus (39.2%) and streptococci (30.2%). EPIs were characterized by a preponderance of virulent microorganisms (S. aureus, Gram-negative bacilli (GNB), enterococci), MDROs (24%) and polymicrobial infections (27.4%). Conversely, coagulase-negative staphylococci (CoNS) and Cutibacterium species were predominant in LCIs (54.5% and 6.1%, respectively) and PICs (57.1% and 15.1%). The percentage of MDROs isolated in EPIs was more than three times the percentage isolated in LCIs (7.8%) and more than twice the proportion found in AHI (10.9%). There was a significant decreasing linear trend over the four time intervals post-surgery for virulent microorganisms, MDROs, and polymicrobial infections, and a rising trend for CoNS, streptococci and Cutibacterium spp. The observed differences have important implications for the empirical antimicrobial treatment of PJIs.

Unprecedented rains decimate surface microbial communities in the hyperarid core of the Atacama Desert

The hyperarid core of the Atacama Desert, the driest and oldest desert on Earth, has experienced a number of highly unusual rain events over the past three years, resulting in the formation of previously unrecorded hypersaline lagoons, which have lasted several months. We have systematically analyzed the evolution of the lagoons to provide quantitative field constraints of large-scale impacts of the rains on the local microbial communities. Here we show that the sudden and massive input of water in regions that have remained hyperarid for millions of years is harmful for most of the surface soil microbial species, which are exquisitely adapted to survive with meager amounts of liquid water, and quickly perish from osmotic shock when water becomes suddenly abundant. We found that only a handful of bacteria, remarkably a newly identified species of Halomonas, remain metabolically active and are still able to reproduce in the lagoons, while no archaea or eukaryotes were identified. Our results show that the already low microbial biodiversity of extreme arid regions greatly diminishes when water is supplied quickly and in great volumes. We conclude placing our findings in the context of the astrobiological exploration of Mars, a hyperarid planet that experienced catastrophic floodings in ancient times.

Fusobacterium nucleatum prosthetic hip infection: Case report and review of the literature of unusual anaerobic prosthetic joint infection

The anaerobic Gram-negative rod Fusobacterium nucleatum is an oral commensal and periodontal pathogen that has been associated with a wide variety of infections, yet it is extremely rare to be associated with prosthetic joint infection. After an exhaustive literature review, only two cases of prosthetic joint infection by F. nucleatum have been previously reported. To our knowledge, the case we report on here is the first combined with periprosthetic abscess and related with hemochromatosis. We therefore sought to provide a comprehensive literature review of case reports or series of less commonly encountered anaerobic microorganisms isolated from prosthetic joint infections.

Accuracy of different diagnostic tests for early, delayed and late prosthetic joint infection

Background

A combination of laboratory, histopathological and microbiological tests for diagnosis of prosthetic joint infection (PJI) have been strongly recommended. This study aims to characterize the accuracy of individual or group tests, such as culture of sonicate fluid, synovial fluid and peri-implant tissue, C-reactive protein (CRP) and histopathology for detection of early, delayed and late PJI.

Methods

A prospective study of patients undergoing hip or knee arthroplasty from February 2009 to February 2014 was performed in a Spanish tertiary health care hospital. The diagnostic accuracy of the different methods was evaluated constructing receiver-operating-characteristic (ROC) curve areas.

Results

One hundred thirty consecutive patients were included: 18 (13.8%) early PJI, 35 (27%) delayed PJI and 77 (59.2%) late PJI. For individual parameters, the area under the ROC curve for peri-implant tissue culture was larger for early (0.917) than for delayed (0.829) and late PJI (0.778), p = 0.033. There was a significantly larger difference for ROC area in the synovial fluid culture for delayed (0.803) than for early (0.781) and late infections (0.679), p = 0.039. The comparison of the areas under the ROC curves for the two microbiological tests showed that sonicate fluid was significantly different from peri-implant tissue in delayed (0.951 vs 0.829, p = 0.005) and late PJI (0.901 vs 0.778, p = 0.000). The conjunction of preoperative parameters, synovial fluid culture and CRP, improved the accuracy for late PJI (p = 0.01). The conjunction of histopathology and sonicate fluid culture increased the area under ROC curve of sonication in early (0.917 vs 1.000); p = 0.06 and late cases (0.901 vs 0.999); p < 0.001.

Conclusion

For early PJI, sonicate fluid and peri-implant tissue cultures achieve the same best sensitivity. For delayed and late PJI, sonicate fluid culture is the most sensitive individual diagnostic method. By combining histopathology and peri-implant tissue, all early, 97% of delayed and 94.8% of late cases are diagnosed. The conjunction of histopathology and sonicate fluid culture yields a sensitivity of 100% for all types of infection.

The Not-So-Good Prognosis of Streptococcal Periprosthetic Joint Infection Managed by Implant Retention: The Results of a Large Multicenter Study

BACKGROUND.

Streptococci are not an infrequent cause of periprosthetic joint infection (PJI). Management by debridement, antibiotics, and implant retention (DAIR) is thought to produce a good prognosis, but little is known about the real likelihood of success.

METHODS.

A retrospective, observational, multicenter, international study was performed during 2003-2012. Eligible patients had a streptococcal PJI that was managed with DAIR. The primary endpoint was failure, defined as death related to infection, relapse/persistence of infection, or the need for salvage therapy.

RESULTS.

Overall, 462 cases were included (median age 72 years, 50% men). The most frequent species was Streptococcus agalactiae (34%), and 52% of all cases were hematogenous. Antibiotic treatment was primarily using β-lactams, and 37% of patients received rifampin. Outcomes were evaluable in 444 patients: failure occurred in 187 (42.1%; 95% confidence interval, 37.5%-46.7%) after a median of 62 days from debridement; patients without failure were followed up for a median of 802 days. Independent predictors (hazard ratios) of failure were rheumatoid arthritis (2.36), late post-surgical infection (2.20), and bacteremia (1.69). Independent predictors of success were exchange of removable components (0.60), early use of rifampin (0.98 per day of treatment within the first 30 days), and long treatments (≥21 days) with β-lactams, either as monotherapy (0.48) or in combination with rifampin (0.34).

CONCLUSIONS.

This is the largest series to our knowledge of streptococcal PJI managed by DAIR, showing a worse prognosis than previously reported. The beneficial effects of exchanging the removable components and of β-lactams are confirmed and maybe also a potential benefit from adding rifampin.

Short- versus long-duration levofloxacin plus rifampicin for acute staphylococcal prosthetic joint infection managed with implant retention: a randomised clinical trial

Levofloxacin plus rifampicin (L+R) is the treatment of choice for acute staphylococcal prosthetic joint infection (PJI) managed with debridement and implant retention (DAIR). Long courses have been empirically recommended, but some studies have suggested that shorter treatments could be as effective. Our aim was to prove that a short treatment schedule was non-inferior to the standard long schedule. An open-label, multicentre, randomised clinical trial (RCT) was performed. Patients with an early post-surgical or haematogenous staphylococcal PJI, managed with DAIR and initiated on L+R were randomised to receive 8 weeks of treatment (short schedule) versus a long schedule (3 months or 6 months for hip or knee prostheses, respectively). The primary endpoint was cure rate. From 175 eligible patients, 63 were included (52% women; median age, 72 years): 33 patients (52%) received the long schedule and 30 (48%) received the short schedule. There were no differences between the two groups except for a higher rate of polymicrobial infection in the long-schedule group (27% vs. 7%; P = 0.031). Median follow-up was 540 days. In the intention-to-treat analysis, cure rates were 58% and 73% in patients receiving the long and short schedules, respectively (difference -15.7%, 95% CI -39.2% to 7.8%). Forty-four patients (70%) were evaluable per-protocol: cure rates were 95.0% and 91.7% for the long and short schedules, respectively (difference 3.3%, 95% CI -11.7% to 18.3%). This is the first RCT suggesting that 8 weeks of L+R could be non-inferior to longer standard treatments for acute staphylococcal PJI managed with DAIR.

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.

Gram-negative prosthetic joint infection: outcome of a debridement, antibiotics and implant retention approach. A large multicentre study

We aim to evaluate the epidemiology and outcome of gram-negative prosthetic joint infection (GN-PJI) treated with debridement, antibiotics and implant retention (DAIR), identify factors predictive of failure, and determine the impact of ciprofloxacin use on prognosis. We performed a retrospective, multicentre, observational study of GN-PJI diagnosed from 2003 through to 2010 in 16 Spanish hospitals. We define failure as persistence or reappearance of the inflammatory joint signs during follow-up, leading to unplanned surgery or repeat debridement>30 days from the index surgery related death, or suppressive antimicrobial therapy. Parameters predicting failure were analysed with a Cox regression model. A total of 242 patients (33% men; median age 76 years, interquartile range (IQR) 68-81) with 242 episodes of GN-PJI were studied. The implants included 150 (62%) hip, 85 (35%) knee, five (2%) shoulder and two (1%) elbow prostheses. There were 189 (78%) acute infections. Causative microorganisms were Enterobacteriaceae in 78%, Pseudomonas spp. in 20%, and other gram-negative bacilli in 2%. Overall, 19% of isolates were ciprofloxacin resistant. DAIR was used in 174 (72%) cases, with an overall success rate of 68%, which increased to 79% after a median of 25 months' follow-up in ciprofloxacin-susceptible GN-PJIs treated with ciprofloxacin. Ciprofloxacin treatment exhibited an independent protective effect (adjusted hazard ratio (aHR) 0.23; 95% CI, 0.13-0.40; p<0.001), whereas chronic renal impairment predicted failure (aHR, 2.56; 95% CI, 1.14-5.77; p 0.0232). Our results confirm a 79% success rate in ciprofloxacin-susceptible GN-PJI treated with debridement, ciprofloxacin and implant retention. New therapeutic strategies are needed for ciprofloxacin-resistant PJI.

Endogenous ocular candidiasis: Changes in epidemiology and factors associated with poor functional outcome

The evolution of the incidence and the epidemiology of ocular candidiasis in our hospital during the past 12 y, as well as the factors associated with poor functional outcome were analysed. A retrospective study of all cases of ocular candidiasis admitted to a university hospital between 1993 and 2004 was performed. Epidemiological, clinical and final outcome data were recorded. 37 episodes of ocular candidiasis in 36 patients were studied. 28 (75%) episodes occurred between 1993 and 1998 (13.09 episodes/100,000 admissions/y), and all of these patients were intravenous drug users. In contrast, only 9 episodes of ocular candidiasis were recorded between 1999 and 2004 (4.42 episodes/100,000 admissions/y; p<.0001) and 3 (33%) patients were not drug users (p<0.01). 19 (57%) cases had final visual acuity <0.1. Treatment with conventional amphotericin B instead of other newer antifungal drugs was associated with poor visual prognosis in the univariate (p = 0.03) and multivariate (p = 0.03) analysis. In conclusion, the incidence of ocular candidiasis has decreased significantly in recent y and the epidemiology has changed. Currently, one-third of patients are immunocompromised non-drug users. Therapy with conventional amphotericin B instead of newer antifungal drugs appears to be associated with a poorer functional outcome.

Piomiositis: una revisión retrospectiva en un hospital terciario del norte de España

OBJECTIVE

To describe the clinical, radiological and microbiological features of a series of patients diagnosed with pyomyositis in a tertiary care university-affiliated center over a 12-year period.

PATIENTS AND METHODS

The medical records of all patients diagnosed with pyomyositis between January 1992 and December 2003 were reviewed. The charts were retrieved from the hospital database. Data were extracted according to a standardized protocol and included clinical, radiological, laboratory and microbiological parameters.

RESULTS

A total of 54 patients (mean age, 50 years, 61% men) had pyomyositis. The most frequent predisposing factors were diabetes mellitus (22%) and traumatic injury (20%), followed by neoplasms (9%). Primary pyomyositis was diagnosed in 25 patients (55%), and a contiguous source of infection was detected in the remainder, with skin infection being the most frequent (40%). The most common presentation was isolated inflammatory signs with or without other symptoms (94%). Isolated fever was documented in only one patient. Ultrasonography was the most common diagnostic procedure performed (32%), followed by CT scanning (18%). Forty-five patients underwent a drainage procedure combined with antibiotic therapy. Pyomyositis was monomicrobial in 20 cases, and polymicrobial in 12. The most frequent pathogen was Staphylococcus aureus followed by coagulase-negative staphylococci (6 cases). Sepsis developed in 4 patients, and recurrence was observed in 8 (15%). Mortality was 10% (5 patients).

CONCLUSIONS

Pyomyositis is a relatively uncommon infection in temperate climates, and is often considered late in the diagnostic workup. Physicians should bear this disease in mind to avoid diagnostic delays and initiate prompt therapy, in order to improve the prognosis of these patients.

Encephalopathy secondary to imipenem therapy

We describe the case of an 84-year-old woman who developed a confusional state and suffered from a generalized tonic-clonic seizure while she was treated with imipenem, a beta-lactam antibiotic. Focal and generalized epileptiform discharges and a photoparoxysmal response were prominent with transient changes on the EEG.