Tolerability and efficacy of long-term treatment with daptomycin, ceftazidime and colistin in a patient with a polymicrobial, multidrug-resistant prosthetic joint reinfection: a case report

Compassionate use of cefiderocol in a complex case of extensively drug-resistant Acinetobacter baumannii fracture-related infection: a comprehensive approach and multidisciplinary management

PURPOSE

Fracture-related infections (FRI) pose a difficult management problem, as they require numerous surgical interventions and extended antibiotic treatments, especially when a multidrug-resistant organism is involved, with a paucity of available literature that provides guidance.

RESULTS

A 42 year-old male presents an open diaphyseal tibia and fibula fracture, complicated by soft tissue necrosis and infections caused by extensively drug-resistant Acinetobacter baumannii (XDR-Ab). Initially treated with a damage control external fixator, the patient underwent multiple surgical procedures, including radical debridement, negative pressure wound therapy, external fixator revisions and reconstructive surgery using a latissimus dorsi free flap. The emergence of colistin resistance in the Acinetobacter baumannii strain led to the compassionate use of cefiderocol, finally achieving clinical cure.

CONCLUSIONS

This case report is one of the firsts that highlights the potential efficacy of cefiderocol in treating challenging bone and joint infections sustained by XDR-Ab. The successful outcome also emphasizes the importance of a comprehensive, multidisciplinary approach in achieving favorable results in complex FRI.

Outcomes of Enterobacter cloacae-Associated Periprosthetic Joint Infection Following Hip Arthroplasties

Background

Periprosthetic joint infections (PJIs) represent a serious complication following total hip arthroplasty (THA) and are associated with significant morbidity. While recent data suggest that Enterobacter cloacae is an emerging source of PJI, characteristics and outcomes of E. cloacae-associated infections are rarely described. The study aimed to present and describe the findings and outcomes of E. cloacae-associated PJI in our department.

Methods

This is a retrospective descriptive study of patients who underwent revision THA for E. cloacae-associated PJI between 2011 and 2020 and has a minimum follow-up of 2 years. Outcomes included organism characteristics as well as clinical outcomes, represented by the number of reoperations needed for PJI eradication and the Musculoskeletal Infection Society (MSIS) outcome reporting tool score. Of 108 revision THAs, 12 patients (11.1%) were diagnosed with E. cloacae-associated PJI.

Results

The majority of cases had a polymicrobial PJI (n=8, 66.7%). Five E. cloacae strains (41.7%) were gentamicin-resistant. Six patients (50.0%) underwent 2 or more revisions, while 3 of them (25.0%) required 4 or more revisions until their PJI was resolved. When utilizing the MSIS outcome score, the first surgical intervention was considered successful (MSIS score tiers 1 and 2) for 5 patients (41.7%) and failed (tiers 3 and 4) for 7 patients (58.3%).

Conclusions

E. cloacae is emerging as a common source of PJI following hip arthroplasty procedures. The findings of our study suggest that this pathogen is primarily of polymicrobial nature and represents high virulence and poor postoperative outcomes, as represented by both an increased number of required revision procedures and high rates of patients with MSIS outcome scores of 3 and 4. When managing patients with E. cloacae-associated PJI, surgeons should consider these characteristics and inform patients regarding predicted outcomes.

Osteosynthesis-associated infection of the lower limbs by multidrug-resistant and extensively drug-resistant Gram-negative bacteria: a multicentre cohort study

Purpose: The purpose of this study was the clinical and therapeutic assessment of lower-limb osteosynthesis-associated infection (OAI) by multidrug-resistant (MDR) and extensively drug-resistant (XDR) Gram-negative bacteria (GNB), which have been poorly studied to date. Methods: A prospective multicentre observational study was conducted on behalf of ESGIAI (the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) Study Group on Implant-Associated Infections). Factors associated with remission of the infection were evaluated by multivariate and Cox regression analysis for a 24-month follow-up period. Results: Patients ( n = 57 ) had a history of trauma (87.7 %), tumour resection (7 %) and other bone lesions (5.3 %). Pathogens included Escherichia coli ( n = 16 ), Pseudomonas aeruginosa ( n = 14 ; XDR 50 %), Klebsiella spp. ( n = 7 ), Enterobacter spp. ( n = 9 ), Acinetobacter spp. ( n = 5 ), Proteus mirabilis ( n = 3 ), Serratia marcescens ( n = 2 ) and Stenotrophomonas maltophilia ( n = 1 ). The prevalence of ESBL (extended-spectrum β -lactamase), fluoroquinolone and carbapenem resistance were 71.9 %, 59.6 % and 17.5 % respectively. Most patients ( n = 37 ; 64.9 %) were treated with a combination including carbapenems ( n = 32 ) and colistin ( n = 11 ) for a mean of 63.3 d. Implant retention with debridement occurred in early OAI (66.7 %), whereas the infected device was removed in late OAI (70.4 %) ( p = 0.008 ). OAI remission was achieved in 29 cases (50.9 %). The type of surgery, antimicrobial resistance and duration of treatment did not significantly influence the outcome. Independent predictors of the failure to eradicate OAI were age > 60  years (hazard ratio, HR, of 3.875; 95 % confidence interval, CI95 %, of 1.540-9.752; p = 0.004 ) and multiple surgeries for OAI (HR of 2.822; CI95 % of 1.144-6.963; p = 0.024 ). Conclusions: Only half of the MDR/XDR GNB OAI cases treated by antimicrobials and surgery had a successful outcome. Advanced age and multiple surgeries hampered the eradication of OAI. Optimal therapeutic options remain a challenge.

Prosthetic joint infection diagnosis applying the three-level European Bone and Joint Infection Society (EBJIS) approach

Sensitive and specific tests for the diagnosis of prosthetic joint infection (PJI) are lacking. The aim of this study was to report clinical and microbiological findings of consecutive patients diagnosed with PJI at the University Hospital of Perugia, Perugia, Italy, and to validate these diagnoses utilizing the European Bone and Joint Infection Society (EBJIS) three-level diagnostic approach from 2021. Patients with a PJI diagnosis were included in this study and examined retrospectively. Overall, 133 patients were diagnosed with PJI: mean age 72 years, 54.9% female, and 55.6% with more than one comorbidity. The most frequent involved joints were hip 47% and knee 42%. Aetiology was identified in 88/133 (66.2%): staphylococci resulted the most frequent microorganisms and over 80% (45/54) resulted rifampin susceptible. Applying the EBJIS approach, PJI diagnosis resulted: confirmed in 101 (75.9%), likely in 25 (18.8%), and unlikely in 7 (5.3%). Likely PJIs aetiology was Staphylococcus aureus 11/25, coagulase-negative staphylococci 8/25, Streptococcus agalactiae 3/25, viridans group streptococci 2/25, and Pseudomonas aeruginosa 1/25. No statistically significant differences were detected among the three diagnosis groups with regard to clinical characteristics with the exception of a higher number of confirmed PJIs occurring < 3 months after implantation. The logistic regression analysis did not disclose any independent predictor of confirmed PJIs. We recommend using all the diagnostic tests available to approach PJI diagnosis, and suggest caution before rejecting PJI diagnosis in the presence of highly virulent microorganisms from a single sample, in patients without sinus tract, and in those receiving antimicrobial at the time microbiologic samples are collected. Study approved by Umbrian Regional Ethical Committee, Perugia, Italy, Prot. N. 23,124/21/ON of 10.27.2021.

The risk factors of polymicrobial periprosthetic joint infection: a single-center retrospective cohort study

BACKGROUND

Periprosthetic joint infection is a serious complication after total joint arthroplasty and polymicrobial PJI which compose a subtype of PJI often indicate worse outcomes compared to monomicrobial periprosthetic joint infection. However, a literature review suggested that there were limited number studies evaluating the risk factors of polymicrobial PJI.

MATERIALS AND METHODS

Between 2015 January and 2019 December, a total of 64 polymicrobial PJI patients and 158 monomicrobial PJI patients in a tertiary center were included in this study and corresponding medical records were scrutinized. The diagnosis of PJI was based on 2014 MSIS criteria. Logistic regression was used to identify the association between various variables and polymicrobial PJI and ROC curve was used to identify their efficiency.

RESULTS

The prevalence of polymicrobial PJI is 28.3% in our cohorts. After adjusting for the presence of sinus, previous and knee infection, isolation of enterococci (OR, 3.025; 95%CI (1.277,7.164) p = 0.012), infection with atypical organisms (OR, 5.032;95%CI: (1.470,17.229) p = 0.01), infection with gram-negative organisms (OR, 2.255; 95%CI (1.011,5.031) p = 0.047), isolation of streptococcus spp. (OR, 6; 95%CI (2.094,17.194) p = 0.001), and infection with CNS (OfR, 2.183;95%CI (1.148,4.152) p = 0.017) were risk factors of polymicrobial PJI compared to monomicrobial PJI. However, knee infection is related to a decreased risk of polymicrobial PJI with an adjusted OR = 0.479 (p = 0.023).

CONCLUSION

This study demonstrated that the prevalence of polymicrobial PJI is 28.3% in PJI patients. Moreover, the presence of sinus tract and previous joint revisions were risk factors for identifying different bacterial species in the intraoperative specimens. Therefore, in these PJI cases, it is necessary to examine multiple specimens of both intraoperative tissue and synovial fluid for increasing the detection rate and obtaining resistance information.

Fatal Clostridium Infection in a Leg-Amputated Patient after Unsuccessful Knee Arthroplasty

Prosthetic joint infection (PJI) is a possible complication occurring after prosthesis implantation. We describe the case of a patient with early postoperative multidrug-resistant polymicrobial PJI and mixed infection of the surgical wound. Despite the removal of the prosthesis, the positioning of double-stage exchange, and dehiscence debridement of the surgical wound, the infection continued. Positioning of an external fixator, plastic reconstruction with a skin graft, and continuous (two years) multiple antimicrobial therapy led to the resolution of the knee infection; a knee prosthesis was implanted, but a new infection of the extensus apparatus by multidrug-resistant Klebsiella pnumoniae followed. It was complicated by surgical wound dehiscence, forcing us to remove the prosthesis, put a new external fixator, and continue with the antibiotic treatment, with no results, and, finally, proceed to a leg amputation. Fourteen days after, the patient was discharged in good clinical condition but, fifteen days later, during rehabilitation in another hospital, the patient developed a severe Clostridium difficilis infection with profuse, intense diarrhea, toxic megacolon, and septic shock; despite colectomy and treatment in an intensive care unit, he died four months later. Patients affected by polymicrobial PJI are at high risk of treatment failure and, therefore, should be given a warning, in good time and appropriate form, of the likelihood of leg amputation.

Two-stage revision and systemic antifungal therapy of Candida glabrata primary prosthetic hip infection successfully treated: a case report

BACKGROUND

Overall, fungi are estimated to cause approximately 1% of prosthetic joint infections, Candida glabrata account for less than 10% of these cases. No well-defined treatment strategy is available.

CASE PRESENTATION

A 71-year-old Caucasian man with non-insulin-dependent diabetes was admitted for hip prosthesis revision. For the past 17 years he suffered from recurrent infection of a perianal fistula, the last episode being 1 week before admission, and was prescribed amoxicillin/clavulanate 1 g twice a day. At surgery, the synovial fluid tested positive for infection with the Synovasure® Alpha Defensin Test, and the orthopedic surgeon reported intraoperative evidence of infection. While the synovial fluid failed to grow microorganisms, seven different samples including periprosthetic tissue and the prosthesis grew Candida glabrata. Imipenem 2 g and teicoplanin 600 mg daily were administered during surgery. Also an antibiotic loaded spacer was positioned. A week later micafungin 100 mg a day was added, and after another week imipenem was replaced with ertapenem 1 g once a day. The combination of antibiotics and antifungal was administered for a total of 7 weeks, while he also underwent treatment of the perianal fistula. The reimplantation was performed after an 8-week antibiotic-free interval. Before reimplantation, his erythrocyte sedimentation rate and C-reactive protein level were normal. At reimplant surgery, several samples were collected for microbiology, before administering ertapenem 1 g, teicoplanin 600 mg and micafungin 100 mg once a day. This antimicrobial combination was continued for 15 days until the microbiologic investigations, including culture and molecular testing after sonication technique of the spacer, were reported negative for bacteria and fungi. In this patient, systemic antifungal and extensive debridement allowed for clinical and microbiologic cure.

CONCLUSIONS

Although Candida glabrata prosthetic joint infection is a rare event, the incidence could increase in the future, and there is need for more definitive treatment protocols. Diagnosis depends on culture. Fungal etiology must always be included in the differential diagnosis of prosthetic joint infection.

Polymicrobial Infections in Hip Arthroplasty: Lower Treatment Success Rate, Increased Surgery, and Longer Hospitalization

BACKGROUND

Polymicrobial hip arthroplasty infections are a subset of periprosthetic joint infection (PJI) with distinct challenges representing 10%-47% of PJI.

METHODS

Records were reviewed from all PJIs involving partial or total hip arthroplasty with positive hip cultures between 2005 and 2015 in order to determine baseline characteristics and outcomes including treatment success, surgeries for infection, and days in hospital for infection. Analysis was restricted to patients who had at least 2 years of follow-up after their final surgery or hospitalization for infection. Factors with P-value less than .05 in univariate outcomes analysis were included in multivariable models.

RESULTS

After multivariable analysis, 28 of 95 hip arthroplasty PJIs which were polymicrobial were associated with significantly lower treatment success, more surgery, and longer hospitalizations compared to PJIs which were not polymicrobial. Patients diagnosed with polymicrobial infection later in treatment (4 of 28) had the lowest treatment success rate, underwent the most surgery, and spent the longest time in hospital.

CONCLUSION

Polymicrobial periprosthetic hip infection is a particularly devastating complication of hip arthroplasty associated with decreased likelihood of treatment success, increased surgery for infection, and greater time in hospital. Patients with late polymicrobial infection had the worst outcomes. This investigation further characterizes the natural history of periprosthetic hip infections with more than one infectious organism. Patients who present with a subsequent polymicrobial infection should be educated that they have a particularly difficult treatment course and treatment success may not be possible.

Multidrug-resistant and extensively drug-resistant Gram-negative prosthetic joint infections: Role of surgery and impact of colistin administration

Factors influencing treatment outcome of patients with Gram-negative bacterial (GNB) multidrug-resistant (MDR) and extensively drug-resistant (XDR) prosthetic joint infection (PJIs) were analysed. Data were collected (2000-2015) by 18 centres. Treatment success was analysed by surgery type for PJI, resistance (MDR/XDR) and antimicrobials (colistin/non-colistin) using logistic regression and survival analyses. A total of 131 patients (mean age 73.0 years, 35.9% male, 58.8% with co-morbidities) with MDR (n = 108) or XDR (n = 23) GNB PJI were assessed. The most common pathogens were Escherichia coli (33.6%), Pseudomonas aeruginosa (25.2%), Klebsiella pneumoniae (21.4%) and Enterobacter cloacae (17.6%). Pseudomonas aeruginosa predominated in XDR cases. Isolates were carbapenem-resistant (n = 12), fluoroquinolone-resistant (n = 63) and ESBL-producers (n = 94). Treatment outcome was worse in XDR versus MDR cases (P = 0.018). Success rates did not differ for colistin versus non-colistin in XDR cases (P = 0.657), but colistin was less successful in MDR cases (P = 0.018). Debridement, antibiotics and implant retention (DAIR) (n = 67) was associated with higher failure rates versus non-DAIR (n = 64) (OR = 3.57, 95% CI 1.68-7.58; P < 0.001). Superiority of non-DAIR was confirmed by Kaplan-Meir analysis (HR = 0.36, 95% CI 0.20-0.67) and remained unchangeable by time of infection (early/late), antimicrobial resistance (MDR/XDR) and antimicrobials (colistin/non-colistin) (Breslow-Day, P = 0.737). DAIR is associated with higher failure rates even in early MDR/XDR GNB PJIs versus implant removal. Colistin should be preserved for XDR cases as it is detrimental in MDR infections.

Eradication of Acinetobacter baumannii/Enterobacter cloacae complex in an open proximal tibial fracture and closed drop foot correction with a multidisciplinary approach using the Taylor Spatial Frame®: a case report

Background

Multi-drug-resistant bacteria (e.g. Carbapenem-resistant Acinetobacter baumannii, extended-spectrum betalactamase or carbapenemase-producing enterobacteriaceae) are emerging in early-onset infections. So far, there is no report describing the eradication of these bacteria in a osseous infection of an open proximal tibial fracture in combination with the hexapod technology to address both osseous consolidation and closed drop foot correction.

Case presentation

After sustaining a proximal tibial fracture (Gustilo 3B), a 41-year-old man was primarily treated with open reduction and internal fixation by a locking plate and split-thickness skin graft in the home country. At the time of admission to our hospital there was a significant anterolateral soft tissue defect covered with an already-necrotic split-thickness graft and suspicious secretion. CAT and MRI scans revealed no signs of osseous healing, intramedullary distinctive osteomyelitis, as well as a large abscess zone in the dorsal compartment. Multiple wound smears showed multi-drug-resistant bacteria: Acinetobacter baumannii (Carbapenem resistant) as well as Enterobacter cloacae complex (AmpC overexpression). After implant removal, excessive osseous and intramedullary debridements using the Reamer Irrigator Aspirator (RIA^®) as well as initial negative pressure wound therapy were performed. Colistin hand-modelled chains and sticks were applied topically as well as an adjusted systemic antibiotic scheme was applied. After repetitive surgical interventions, the smears showed bacterial eradication and the patient underwent soft tissue reconstruction with a free vascularized latissimus dorsi muscle flap. External fixation was converted to a hexapod fixator (TSF^®) to correct primary varus displacement, axial assignment and secure osseous healing. A second ring was mounted to address the fixed drop foot in a closed fashion without further intervention. At final follow-up, 12 months after trauma, the patient showed good functional recovery with osseous healing, intact soft tissue with satisfactory cosmetics and no signs of reinfection.

Conclusions

A multidisciplinary approach with orthopaedic surgeons for debridement, planning and establishing osseous and joint correction and consolidation, plastic surgeons for microvascular muscle flaps for soft tissue defect coverage as well as clinical microbiologists for the optimized anti-infective treatment is essential in these challenging rare cases.

Level of evidence

Level IV.

Total hip prosthesis complication, periprosthetic infection with external fistulizing due to Enterobacter cloacae complex multiple drugs resistance: A clinical case report

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The incidence of periprosthetic hip infections his just below 2%, and the Enterobacteriaceae are fairly rare, being the cause of infection in 3–6% of cases.

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A 76 year old woman with multiple comorbidities underwent surgical implantation of endoprosthesis of the left hip.

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Multidisciplinary diagnosis of a rare periprosthetic infection.

Introduction

The Enterobacter cloacae is a microorganism found in the intestinal flora of the majority of animals, including humans. Primary infections caused by E. cloacae are rare in immunocompetent patients, but are very common in hospital settings in newborns and immunocompromised patients, and can be aggravated by the insurgence of antibiotic resistance. The incidence of periprosthetic hip infections is just below 2%.

Case presentation

A 76 year old woman with multiple comorbidities underwent surgical implantation of intermediary total hip prosthesis of the left hip, in a different health facility, in February 2014, after the basicervical fracture of the upper femur extremity due to trauma. After an episode of dislocation of the prosthetic implant, in September 2014, she underwent a surgical operation to implant the acetabular component. A month later not in our facility, following a re-hospitalization for the dislocation of the arthroprosthesis, an infection from E. cloacae complex was discovered. After 2 years of chronic infection she came to our attention; the clinical picture featured coxalgia and secreting fistula in the surgical wound. Following a specific antibiotic therapy, carried out intravenously over the course of a month, we decided to intervene removing the left hip arthroprosthesis and placing an antibiotic spacer following the direction deduced from the antibiogram study of August 2016.

Conclusion

The patient was hospitalized in our facility and 2 months later she underwent another operation to remove the antibiotic spacer and to place a new total hip arthroprosthesis. Multiple swabs showed the complete healing from the infection, which was confirmed a couple of months later.