Clinical, Microbiological and Treatment Characteristics of Severe Postoperative Respiratory Infections: An Observational Cohort Study.

Respiratory infections are frequent and life-threatening complications of surgery. This study aimed to evaluate the clinical, microbiological and treatment characteristics of severe postoperative pneumonia (POP) and tracheobronchitis (POT) in a large series of patients. This single-center, prospective observational cohort study included patients with POP or POT requiring intensive care unit admission in the past 10 years. We recorded demographic, clinical, microbiological and therapeutic data. A total of 207 patients were included, and 152 (73%) were men. The mean (SD) age was 70 (13) years and the mean (SD) ARISCAT score was 46 (19). Ventilator-associated pneumonia was reported in 21 patients (10%), hospital-acquired pneumonia was reported in 132 (64%) and tracheobronchitis was reported in 54 (26%). The mean (SD) number of days from surgery to POP/POT diagnosis was 6 (4). The mean (SD) SOFA score was 5 (3). Respiratory microbiological sampling was performed in 201 patients (97%). A total of 177 organisms were cultured in 130 (63%) patients, with a high proportion of Gram-negative and multi-drug resistant (MDR) bacteria (20%). The most common empirical antibiotic therapy was a triple-drug regimen covering MDR Gram-negative bacteria and MRSA. In conclusion, surgical patients are a high-risk population with a high proportion of early onset severe POP/POT and nosocomial bacteria isolation.

Cutibacterium spp. Infections after Instrumented Spine Surgery Have a Good Prognosis Regardless of Rifampin Use: A Cross-Sectional Study.

Infection after spinal instrumentation (IASI) by Cutibacterium spp. is being more frequently reported. The aim of this study was to analyse the incidence, risk factors, clinical characteristics, and outcome of a Cutibacterium spp. IASI (CG) compared with non-Cutibacterium IASI (NCG) infections, with an additional focus on the role of rifampin in the treatment. All patients from a multicentre, retrospective, observational study with a confirmed IASI between January 2010 and December 2016 were divided into two groups: (CG and NCG) IASI. Baseline, medical, surgical, infection treatment, and follow-up data were compared for both groups. In total, 411 patients were included: 27 CG and 384 NCG. The CG patients were significantly younger. They had a longer median time to diagnosis (23 vs. 13 days) (p = 0.025), although 55.6% debuted within the first month after surgery. Cutibacterium patients were more likely to have the implant removed (29.6% vs. 12.8%; p = 0.014) and received shorter antibiotic regimens (p = 0.014). In 33% of Cutibacterium cases, rifampin was added to the baseline therapy. None of the 27 infections resulted in treatment failure during follow-up regardless of rifampin use. Cutibacterium spp. is associated with a younger age and may cause both early and late IASIs. In our experience, the use of rifampin to improve the outcome in the treatment of a Cutibacterium spp. IASI is not relevant since, in our series, none of the cases had therapeutic failure regardless of the use of rifampin.

Rates and Predictors of Treatment Failure in Staphylococcus aureus Prosthetic Joint Infections According to Different Management Strategies: A Multinational Cohort Study-The ARTHR-IS Study Group.

INTRODUCTION: Guidelines have improved the management of prosthetic joint infections (PJI). However, it is necessary to reassess the incidence and risk factors for treatment failure (TF) of Staphylococcus aureus PJI (SA-PJI) including functional loss, which has so far been neglected as an outcome. METHODS: A retrospective cohort study of SA-PJI was performed in 19 European hospitals between 2014 and 2016. The outcome variable was TF, including related mortality, clinical failure and functional loss both after the initial surgical procedure and after all procedures at 18 months. Predictors of TF were identified by logistic regression. Landmark analysis was used to avoid immortal time bias with rifampicin when debridement, antibiotics and implant retention (DAIR) was performed. RESULTS: One hundred twenty cases of SA-PJI were included. TF rates after the first and all surgical procedures performed were 32.8% and 24.2%, respectively. After all procedures, functional loss was 6.0% for DAIR and 17.2% for prosthesis removal. Variables independently associated with TF for the first procedure were Charlson ≥ 2, haemoglobin < 10 g/dL, bacteraemia, polymicrobial infection and additional debridement(s). For DAIR, TF was also associated with a body mass index (BMI) > 30 kg/m2 and delay of DAIR, while rifampicin use was protective. For all procedures, the variables associated with TF were haemoglobin < 10 g/dL, hip fracture and additional joint surgery not related to persistent infection. CONCLUSIONS: TF remains common in SA-PJI. Functional loss accounted for a substantial proportion of treatment failures, particularly after prosthesis removal. Use of rifampicin after DAIR was associated with a protective effect. Among the risk factors identified, anaemia and obesity have not frequently been reported in previous studies. TRIAL REGISTRATION: This study is registered at clinicaltrials.gov, registration no. NCT03826108.

Staphylococcus aureus is one of the most virulent bacteria and frequently causes prosthetic joint infections.Knowledge of the treatment of this type of infection has advanced in recent years, and treatment guidelines have led to improved management. Typically, the successful treatment of these infections has been determined by clinical cure, that is, the symptoms of infection have disappeared, but has not taken into account loss of function (such as significant difficulties walking), which is critical for the patient's quality of life. Our aim in this study was to evaluate the success of current management strategies for S. aureus prosthetic joint infection, including recovery of functionality, and the factors that predict why some of these infections are not cured, to identify areas for improvement.In a multinational cohort of 128 patients with S. aureus prosthetic joint infection, rates of treatment failure were found to be high, with significant rates of loss of function, especially when the prosthesis needed to be removed. Loss of function was less frequent when the infection was initially treated with surgical cleaning without removal of the prosthesis, even when this procedure failed at first. We found that anaemia and obesity were associated with lower treatment success, and that the probability of treatment success increased when surgical cleaning without prosthesis removal was performed early, and when the antibiotic rifampicin was used in combination with another antibiotic.

Preoperative and perioperative risk factors, and risk score development for prosthetic joint infection due to Staphylococcus aureus: a multinational matched case-control study.

OBJECTIVES: We aim to identify the preoperative and perioperative risk factors associated with post-surgical Staphylococcus aureus prosthetic joint infections (PJI) and to develop and validate risk-scoring systems, to allow a better identification of high-risk patients for more efficient targeted interventions. METHODS: We performed a multicenter matched case-control study of patients who underwent a primary hip and knee arthroplasty from 2014 to 2016. Two multivariable models by logistic regression were performed, one for the preoperative and one for perioperative variables; predictive scores also were developed and validated in an external cohort. RESULTS: In total, 130 cases and 386 controls were included. The variables independently associated with S. aureus-PJI in the preoperative period were (adjusted OR; 95% CI): body mass index >30 kg/m2 (3.0; 1.9 to 4.8), resident in a long-term care facility (2.8; 1.05 to 7.5), fracture as reason for arthroplasty (2.7; 1.4 to 5.03), skin disorders (2.5; 0.9 to 7.04), previous surgery in the index joint (2.4; 1.3 to 4.4), male sex (1.9; 1.2 to 2.9) and American Society of Anesthesiologists index score 3 to 4 (1.8; 1.2 to 2.9). The area under the receiver operating characteristic curve was 0.73 (95% CI 0.68 to 0.78). In perioperative model, the risk factors were the previous ones plus surgical antibiotic prophylaxis administered out of the first 60 minutes before incision (5.9; 2.1 to 16.2), wound drainage for >72 hours after arthroplasty (4.5; 1.9 to 19.4) and use of metal bearing material versus ceramic (1.9; 1.1 to 3.3). The area under the receiver operating characteristic curve was 0.78 (95% CI 0.72 to 0.83). The predictive scores developed were validated in the external cohort. DISCUSSION: Predictive scores for S. aureus-PJI were developed and validated; this information would be useful for implementation of specific preventive measures.

Aminoglycoside or Polymyxin Monotherapy for Treating Complicated Urinary Tract Infections Caused by Extensively Drug-Resistant Pseudomonas aeruginosa: A Propensity Score-Adjusted and Matched Cohort Study.

INTRODUCTION: Extensively drug-resistant (XDR) Pseudomonas aeruginosa (PA) infections are difficult to treat. We aimed to compare aminoglycosides or polymyxin monotherapy versus other antibiotic regimens (carbapenems, aztreonam, ceftazidime, cefepime, ceftolozane-tazobactam, or ceftazidime-avibactam) in complicated urinary tract infections (cUTI) caused by XDR-PA. METHODS: Study performed at a tertiary-care hospital from 2010 to 2019. All consecutive adult patients with XDR-PA urine cultures and diagnosed with cUTI were retrospectively reviewed. XDR phenotype was defined according to Magiorakos et al. A propensity score was used as a covariate in multivariate analyses and for matching. Primary outcome was early clinical failure and at end of treatment (EOT). Main secondary outcomes were 30- and 90-day mortality, microbiological clearance, and antibiotic-related side effects. RESULTS: Of the 465 episodes screened, 101 were included, 48% were treated with aminoglycoside or colistin monotherapy. Most XDR-PA were susceptible to colistin (100%) and amikacin (43%). Patients treated with antibiotic regimens other than aminoglycosides or polymyxin monotherapy were more likely to have hematologic malignancy (p < 0.001), higher SOFA score (p = 0.048), and bacteremia (p = 0.003). In multivariate models adjusted by propensity score, aminoglycoside or colistin monotherapy was not associated with worse outcomes. After propensity score matching, 28 episodes in each treatment group were matched. Adjusted ORs (95% CI) for early clinical failure and at EOT with aminoglycosides or polymyxin monotherapy were 0.53 (0.18-1.58) and 1.29 (0.34-4.83), respectively. Aminoglycoside or colistin monotherapy was not associated with higher 30-day (HR 0.93, 95% CI 0.17-5.08) or 90-day mortality (HR 0.68, 95% CI 0.20-2.31), nor with absence of microbiological clearance (OR 0.72, 95% CI 0.33-1.58). No statistically significant differences were found in terms of nephrotoxicity. Clostridioides difficile infection was observed only in the "other antibiotic regimens" group (n = 6, 11.3%). CONCLUSIONS: Aminoglycosides or polymyxin monotherapy showed good efficacy and safety profile in treating cUTI caused by XDR-PA. These results may be useful for antibiotic stewardship activities.

Implant Removal in the Management of Prosthetic Joint Infection by Staphylococcus aureus: Outcome and Predictors of Failure in a Large Retrospective Multicenter Study.

OBJECTIVES: To compare the characteristics and outcomes of cases with acute prosthetic joint infection (PJI; early post-surgical or hematogenous) by Staphylococcus aureus managed with implant removal (IRm) or debridement and retention (DAIR). To analyze the outcomes of all cases managed with IRm (initially or after DAIR failure). METHODS: Retrospective, multicenter, cohort study of PJI by S. aureus (2003-2010). Overall failure included mortality within 60 days since surgery and local failure due to staphylococcal persistence/relapse. RESULTS: 499 cases, 338 initially managed with DAIR, 161 with IRm. Mortality was higher in acute PJI managed initially with IRm compared to DAIR, but not associated with the surgical procedure, after propensity score matching. Underlying conditions, hemiarthroplasty, and methicillin-resistant S. aureus were risk factors for mortality. Finally, 249 cases underwent IRm (88 after DAIR failure); overall failure was 15.6%. Local failure (9.3%) was slightly higher in cases with several comorbidities, but independent of previous DAIR, type of IRm, and rifampin treatment. CONCLUSIONS: In a large multicenter study of S. aureus PJI managed with IRm, failure was low, but mortality significant, especially in cases with acute PJI and underlying conditions, but not associated with the IRm itself. Rifampin efficacy was limited in this setting.

Infections after spine instrumentation: effectiveness of short antibiotic treatment in a large multicentre cohort.

BACKGROUND AND OBJECTIVES: Available information about infection after spine instrumentation (IASI) and its management are scarce. We aimed to analyse DAIR (debridement, antibiotics and implant retention) prognosis and evaluate effectiveness of short antibiotic courses on early forms. METHODS: Multicentre retrospective study of patients with IASI managed surgically (January 2010-December 2016). Risk factors for failure were analysed by multivariate Cox regression and differences between short and long antibiotic treatment were evaluated with a propensity score-matched analysis. RESULTS: Of the 411 IASI cases, 300 (73%) presented in the first month after surgery, 48 in the second month, 22 in the third and 41 thereafter. Infections within the first 2 months (early cases) occurred mainly to older patients, with local inflammatory signs and predominance of Enterobacteriaceae, unlike those in the later periods. When managed with DAIR, prognosis of early cases was better than later ones (failure rate 10.4% versus 26.1%, respectively; P = 0.02). Risk factors for DAIR failure in early cases were female sex, Charlson Score, large fusions (>6 levels) and polymicrobial infections (adjusted HRs of 2.4, 1.3, 2.6 and 2.26, respectively). Propensity score matching proved shorter courses of antibiotics (4-6 weeks) as effective as longer courses (failure rates 11.4% and 10.5%, respectively; P = 0.870). CONCLUSIONS: IASIs within the first 2 months could be managed effectively with DAIR and shorter antibiotic courses. Clinicians should be cautious when faced with patients with comorbidities, large fusions and/or polymicrobial infections.

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.

Results of cement spacer sonication in the second stage of two-stage treatment of shoulder arthroplasty infection.

BACKGROUND: The objective of this study is to present the results of cement spacer sonication in the second stage of two-stage treatment of shoulder arthroplasty infection and to determine the rate of positive cultures in the second-stage surgery in shoulder arthroplasty and its meaning. METHODS: Twenty-one patients (22 cement spacers) treated with two-stage surgery because of a shoulder arthroplasty infection were included. In the second stage, the cement spacer was sent for sonication and at least four tissue cultures were obtained. Epidemiological data, comorbidities, sensitivity of the microorganisms to the antibiotic loaded in the cement spacer in the first revision surgery, time elapsed since an antibiotic was last administered until second revision procedure, functional shoulder status at last follow-up, and any complication were recorded. RESULTS: Three out of the 22 cases (13.6%) presented positive cultures at the second-stage surgery. Periprosthetic tissue culturing detected the three positive culture cases in the second stage while the cement spacer sonication detected two and missed one. Considering periprosthetic tissue culturing as the standard procedure, the cement spacer sonication showed sensitivity at 66.6%. Recurrent infection over time was considered present in 3 patients; two of them had been previously diagnosed with a positive culture at the second stage (66.6%). CONCLUSIONS: A good number of patients (13.6%) present a positive culture at the second stage of the two-stage surgical procedure for infected shoulder arthroplasty, and those patients seem to be at high risk for recurrent infection. Periprosthetic tissue cultures have a higher sensitivity to detecting a positive culture at the second stage than cement spacer sonication.

Community-onset healthcare-related urinary tract infections: comparison with community and hospital-acquired urinary tract infections.

OBJECTIVES: 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. METHODS: 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. RESULTS: 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 p < 0.01). ESBL-Escherichia coli and Pseudomonas aeruginosa infections were more frequent in HCA than in CA UTI (p = 0.03 and p < 0.01). 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). CONCLUSIONS: 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.

High prevalence of extended-spectrum beta-lactamase-producing enterobacteriaceae in bacteremia after transrectal ultrasound-guided prostate biopsy: a need for changing preventive protocol.

OBJECTIVES: To determine whether the incidence of bacteremia after transrectal ultrasound-guided prostate biopsy (TRUSGPB) significantly diminishes with the setting up of a new preventive protocol. This protocol was set up after detecting an augmented incidence of bacteremia after TRUSGPB with a high prevalence of antibiotic-resistant microorganisms. METHODS: Retrospective descriptive and prospective intervention study performed at a University Hospital. PARTICIPANTS: Patients undergoing TRUSGPB under the old preventive protocol (January 2006-February 2007), that is, amoxicillin-clavulanate 500 mg tid the day before, the day of the procedure, and 1 day after the procedure, and after setting up a new protocol (March 2007-April 2008), that is, 2 g cefoxitin 1 hour before the procedure and ciprofloxacin 750 mg p.o. bid the day before, the day of the procedure, and 3 days after the procedure; dipstick urinalysis was performed before the procedure, and patients with positive results were not biopsied. RESULTS: Incidence of bacteremia with old and new protocols: 9 of 204 procedures (4.4%) vs 2 of 207 (0.9%), (P = .03). Four isolates (44.4%) under the old protocol produced extended-spectrum beta-lactamase (ESBL). With the new protocol, 2 (0.9%) cases of non-ESBL Escherichia coli bacteremia were observed. Sixty-five (23.8%) cases were not biopsied because of positive result of dipstick urinalysis, lack of antibiotic prophylaxis adherence, or altered coagulation parameters. CONCLUSIONS: Antibiotic prophylaxis for TRUSGPB should take into account local resistance patterns. Cefoxitin could be used as prophylaxis in centers with high prevalence of ESBL enterobacteriaceae. Before TRUSGPB, excluding patients with positive results of dipstick urinalysis is an advisable practice.