Fungal biofilms in human health and disease

Increased use of implanted medical devices, use of immunosuppressants and an ageing population have driven the rising frequency of fungal biofilm-related diseases. Fungi are now recognized by the World Health Organization (WHO) as an emergent threat to human health, with most medically important species defined as critical or high-priority organisms capable of forming biofilms. Although we strive for a better understanding of diagnostic and therapeutic approaches to detect and treat these fungal diseases more generally, the issue of hard-to-treat biofilms is an ever-increasing problem. These are communities of interspersed cells that are attached to one another on a surface, such as a catheter, or trapped into a cavity such as a paranasal sinus. Biofilms are difficult to detect, difficult to remove and intrinsically tolerant to most antifungal agents. These factors can lead to devastating consequences for the patient, including unnecessary morbidity and mortality, need for reoperations and prolonged hospital stay. This Review describes the breadth and growing impact fungal biofilms have on patient management and explains the mechanisms promoting biofilm formation, focusing on how targeting these can improve therapeutic options.

Fungal versus non-fungal supra-inguinal prosthetic vascular graft infections: A cohort study

OBJECTIVES

Fungal prosthetic vascular graft infections are rare and mainly supra-inguinal. Current guidelines are based on the few studies that have specifically investigated this population, with few risk factors described. The objective of this study is to compare fungal and non-fungal supra-inguinal prosthetic vascular graft infections (PVGI), describing their specificities, identifying risk factors, and evaluating outcomes.

PATIENTS AND METHODS

This is a single-center retrospective cohort study carried out at the Pitié-Salpêtrière Hospital in Paris, including all patients who were treated for a supra-inguinal PVGI between January 1st, 2009 and February 28th, 2021. Preoperative, intraoperative and postoperative data were compared between fungal and non-fungal PVGI.

RESULTS

Out of the 475 patients screened, 148 developed a supra-inguinal PVGI: 32 fungal and 116 non-fungal. Factors independently associated with fungal PVGI were presence of a prostheto-digestive fistula (OR 5.98; 95% CI 2.29-15.62) and preoperative antibiotic therapy of seven days or more (OR 2.87; 95% CI 1.12-7.38). Mortality rate at 180 days was significantly higher for fungal as compared to non-fungal PVGIs (38% vs. 16% p = 0.009) and for fungal PVGI with prostheto-digestive fistula. However, there was no statistically significant relation between mortality due to prostheto-digestive fistula in contrast with fungal PVGI alone (p = 0.21).

CONCLUSION

Prostheto-digestive fistula was strongly associated with fungal PVGI, which leads us to suggest that in such cases, an anti-fungal agent should be prescribed.

Robotic-assisted closed-chest management of a fungal-infected prosthetic aortic graft: a case report

Background

Fungal prosthetic graft infections are associated with high mortality, typically requiring aggressive surgical debridement. We present an alternative, minimally invasive approach to address these challenging clinical cases.

Case presentation

A 76-year-old Caucasian male with prior aortic root and arch replacement presented with localized chest wall tenderness after being hit by a car door. Computed tomography angiogram incidentally identified fluid in the anterior mediastinum, surrounding his ascending aortic graft. Rather than undertaking a high-risk reoperative sternotomy and redo complex aortic reconstruction, we elected to proceed with a robotic-assisted, minimally invasive debridement of the aortic graft, coupled with an omental wrap, entirely within the closed chest. Microbiology was positive for Aspergillus species. The patient made an uncomplicated recovery and was discharged home on antifungal therapy, likely to continue indefinitely.

Conclusions

Infected prosthetic aortic grafts can be successfully managed with debridement and pedicled omental flap coverage via a minimally invasive approach within the closed chest, obviating the morbidity of a complex reoperative open procedure.

Endocarditis in patients with ascending aortic prosthetic graft: a case series from a national multicentre registry

OBJECTIVES

Endocarditis in patients with ascending aortic prosthetic graft (AAPG) is a life-threatening complication. The purpose of this study was to examine the clinical presentation and prognosis of patients with AAPG endocarditis included in a large prospective infectious endocarditis multicentre study.

METHODS

From January 2008 to April 2015, 3200 consecutive patients with infectious endocarditis according to the modified Duke criteria, were prospectively included in the 'Spanish Collaboration on Endocarditis Registry (GAMES)' registry. Twenty-seven definite episodes of endocarditis (0.8%) occurred in patients with AAPG.

RESULTS

During the study period, 27 cases of endocarditis were detected in patients with AAPG. The median age of patients was 61 years [interquartile range (IQR) 51-68 years] and 23 (85.2%) patients were male. The median time from AAPG surgery to the episode of AAPG infection was 24 months (IQR 6-108 months). The most frequently isolated micro-organisms were coagulase-negative staphylococci and S. aureus (11 patients, 40.7%). Four patients (14.8%) underwent medical treatment, whereas surgery was performed in 21 (77.7%). Two patients (7.4%) died before surgery could be performed. The median hospital stay prior to surgery was 7 days (IQR 4-21 days). Surgery consisted of replacing previous grafts with a composite aortic graft (10 cases) or aortic homograft (2 patients), and removal of a large vegetation attached to the valve of a composite tube (1 case). Nine patients had an infected aortic valve prosthesis without evidence of involvement of the AAPG. Isolated redo-aortic valve replacement was performed in 8 (88.9%) of these patients. Reinfection occurring during 1 year of follow-up was not detected in any patient. Two patients (7.4%) died while awaiting surgery and 6 did so after surgery (22.2%). A New York Heart Association (NYHA) Class IV was associated with mortality in patients undergoing surgery (P < 0.019).

CONCLUSIONS

Most cases of endocarditis in patients with AAPG occur late after initial surgery. Mortality rate of patients with AAPG endocarditis who undergo surgery is acceptable. NYHA Class IV before surgery is associated with an increased postoperative mortality.