Multidisciplinary Management of Sternal Osteomyelitis Due to Klebsiella aerogenes after Open Heart Surgery in a Patient with Multiple Myeloma: A Case Report and Discussion of the Literature.

Sternal wound complications following cardiac surgery, including sternal dehiscence, mediastinitis, and osteomyelitis, pose significant challenges in terms of management and patient outcomes. We present a case report highlighting the complex management of a patient who underwent open heart surgery for severe aortic valve stenosis, followed by sternal wound dehiscence and sternum osteomyelitis due to extended spectrum beta lactamase (ESBL) producing Klebsiella aerogenes. A multiple myeloma diagnosis was also suspected at the positron emission tomography (PET) scan and confirmed with bone marrow biopsy. Multidisciplinary evaluation of the case led to a comprehensive treatment plan. To control the sternal osteomyelitis, total sternectomy was performed followed by immediate reconstruction with a bone (tibia) graft from the tissue bank and fixation with the minimal hardware possible. A microsurgical latissimus dorsi free flap was required to reconstruct the soft tissue defect. After 6 weeks of antibiotic treatment with ertapenem and fosfomycin based on a culture of intraoperative material, no clinical, imaging, or laboratory signs of infection were seen. Multiple myeloma treatment was then started. At 1 year of follow up, no recurrence of infection occurred, and the reconstruction was stable and closed. Multiple myeloma is under chronic treatment with novel agent combination, with an excellent haematological response.

A retrospective multicentre study on dalbavancin effectiveness and cost-evaluation in sternotomic wound infection treatment: DALBA SWIT Study.

OBJECTIVE: To evaluate the cost-effectiveness of dalbavancin compared with standard of care (SoC) treatment as daptomycin or teicoplanin in patients with sternal wound infections (SWI). METHODS: Multicentre retrospective study of patients diagnosed with SWI from January 2016 to December 2019 at two cardiac surgery facilities treated with dalbavancin, teicoplanin or daptomycin. Patients with SWI treated with dalbavancin were compared with SoC to evaluate resolution of infection at 90 and 180 days from infection diagnosis, length of stay (LoS) and management costs. RESULTS: 48 patients with SWI were enrolled, 25 (50%) male, median age 67 (60-73) years, Charlson index score 5 (4-7). Fifteen patients were treated with dalbavancin (31%) and 33 with SoC (69%): teicoplanin in 21 (63%), and daptomycin in 12 (37%). Staphylococcus species were the most frequent isolates (44, 92%), mostly (84%) resistant to methicillin. All patients were treated with surgical debridement followed by negative pressure wound therapy. Wound healing at day 90 and 180 was achieved in 46 (95.8%) and 34 (82.9%) of patients, respectively. A shorter length of hospitalization in patients treated with dalbavancin compared with SoC [12 (7-18) days vs 22 (12-36) days, p:0.009] was found. Treatment with dalbavancin resulted in total cost savings of €16 026 (95% CI 5976-26 076, P < 0.001). Savings were mainly related to the LoS that was significantly shorter in the dalbavancin group, generating significantly lower cost compared to SoC group. CONCLUSION: Dalbavancin treatment of sternal wound infections is effective and seems to reduce hospitalization length, leading to significantly lower costs.

Risk factors for persistent enterococcal bacteraemia: a multicentre retrospective study.

OBJECTIVES: Conditions favouring persistent enterococcal bacteraemia (p-EB) have not been fully investigated yet. The aim of our study is to analyse risk factors for p-EB and its impact on mortality. METHODS: International two-centre retrospective study of all hospitalised adults with enterococcal bacteraemia managed with follow-up blood cultures (BCs) during the period 2011-2019. Exclusion criteria were: (1) death within 72 hours from index BCs and (2) polymicrobial bacteraemia. Primary endpoint was p-EB, defined as further isolation of the same species of Enterococcus spp. from BCs after at least 72 hours of appropriate antibiotic therapy. Multivariable logistic regression model was performed to assess risk factors for p-EB. The impact of p-EB on 30-day mortality was assessed by Kaplan-Meier survival curve and Cox regression multivariable model. RESULTS: During the study period, 244 enterococcal bacteraemia were diagnosed. P-EB were 13.5% (33/244). At multivariable analysis, factors independently associated with p-EB were hematologic malignancy (OR 4.60 [95% CI 1.32-16.00], P = 0.01), infective endocarditis (OR 7.99 [95% CI 2.20-28.9], P = 0.002), and use of daptomycin as initial treatment (OR 4.50 [95% CI 1.29-15.61], P = 0.018). Mortality rate was higher in the p-EB group (32% vs. 18%). Kaplan-Meier survival curve showed that patients with p-EB were less likely to survive at 30 days from index BCs (log-rank P = 0.002). Using a Cox regression model, independent predictors of 30-day mortality were hematologic malignancy (HR 2.30 [95% CI 1.02-4.11], P = 0.043), p-EB (HR 1.93 [95% CI 0.92-4.04], P = 0.08), and septic shock (HR 5.92 [95% CI 2.17-16.30], P = 0.001). CONCLUSION: P-EB was diagnosed mainly in very fragile patients and in those receiving daptomycin as frontline therapy. P-EB may have an impact on mortality.

Pseudozyma aphidis bloodstream infection in a patient with aggressive lymphoma and a history of intravenous drug use: Case report and review of the literature.

Pseudozyma aphidis is an environmental fungus which causes opportunistic infections in immunocompromised patients. Here we report the case of a 54-year-old, intravenous drug user woman, newly diagnosed to have an aggressive lymphoma, who developed a bloodstream infection caused by P. aphidis treated successfully with amphotericin-B therapy. The precise identification was assessed by sequencing. We propose to consider intravenous drug use as a risk factor for invasive infections due to this environmental yeast.

Risk Factors for Candidemia After Open Heart Surgery: Results From a Multicenter Case-Control Study.

BACKGROUND: Candida species are among the most frequent causative agents of health care-associated bloodstream infections, with mortality >40% in critically ill patients. Specific populations of critically ill patients may present peculiar risk factors related to their reason for intensive care unit admission. The primary objective of the present study was to assess the predictors of candidemia after open heart surgery. METHODS: This retrospective, matched case-control study was conducted in 8 Italian hospitals from 2009 to 2016. The primary study objective was to assess factors associated with the development of candidemia after open heart surgery. RESULTS: Overall, 222 patients (74 cases and 148 controls) were included in the study. Candidemia developed at a median time (interquartile range) of 23 (14-36) days after surgery. In multivariable analysis, independent predictors of candidemia were New York Heart Association class III or IV (odds ratio [OR], 23.81; 95% CI, 5.73-98.95; P < .001), previous therapy with carbapenems (OR, 8.87; 95% CI, 2.57-30.67; P = .001), and previous therapy with fluoroquinolones (OR, 5.73; 95% CI, 1.61-20.41; P = .007). Crude 30-day mortality of candidemia was 53% (39/74). Septic shock was independently associated with mortality in the multivariable model (OR, 5.64; 95% CI, 1.91-16.63; P = .002). No association between prolonged cardiopulmonary bypass time and candidemia was observed in this study. CONCLUSIONS: Previous broad-spectrum antibiotic therapy and high NYHA class were independent predictors of candidemia in cardiac surgery patients with prolonged postoperative intensive care unit stay.

Clinical experience with dalbavancin for the treatment of deep sternal wound infection.

OBJECTIVES: Deep sternal wound infection (DSWI) is a complication of major heart surgery with high morbidity as well as prolonged antimicrobial treatment and hospital length of stay (LoS). Dalbavancin is a new lipoglycopeptide antibiotic active against Gram-positive micro-organisms, including methicillin-resistant Staphylococcus aureus (MRSA), with a long half-life. This small case series assessed the feasibility of dalbavancin for the treatment of DSWI. METHODS: This was retrospective, observational, cohort study of patients treated with dalbavancin for DSWI over a 2-year period (March 2016 to April 2018) in two cardiac surgery departments in Italy. All patients with DSWI underwent surgical accurate debridement. Dalbavancin was administered during the hospital stay or in an outpatient facility. RESULTS: Among 15 patients enrolled in the study, MRSA was isolated in 7 (47%), methicillin-resistant Staphylococcus epidermidis in 6 (40%) and other coagulase-negative staphylococci in 2 (13%). Dalbavancin was administered by two infusions in 9 patients (60%), whereas 5 patients (33%) received a median of four doses. Fourteen patients received a first dose of 1000mg followed by 500mg, whereas one patient received two doses of 1500mg each. All patients were defined as clinically cured. The median hospital LoS was 13 days (interquartile range, 8-18 days). At 6 months after discharge, 14 patients (93%) showed no relapse of DSWI, whereas 1 patient recurred with a diagnosis of DSWI caused by another pathogen (Candida sp.). CONCLUSION: Dalbavancin may be an alternative option for DSWI caused by Gram-positive bacteria when first-line treatments are contraindicated or as salvage treatment.

Sphingomonas paucimobilis osteomyelitis in an immunocompetent patient. A rare case report and literature review.

Sphingomonas paucimobilis occurs widely both in natural and nosocomial environments, including hospital water systems, respiratory therapy equipment, and laboratory instruments. It is an opportunistic pathogen that rarely causes infections in humans. Among S. paucimobilis nosocomial infections, osteomyelitis is particularly rare. Almost all infections occur in patients with comorbidities such as malignancy, immunosuppressant therapy, diabetes mellitus and acquired immunodeficiency syndrome. We present the first case of Sphingomonas paucimobilis osteomyelitis in an immunocompetent patient and include updated literature concerning infections by this microorganism.