Fatal Scopulariopsis infection in a lung transplant recipient: lessons of organ procurement

Clinical approach to donor-derived infection in solid organ transplant recipients

Donor-derived infection is an uncommon but potentially devastating complication of solid organ transplantation (SOT). Accurate and timely identification of unexpected infectious disease transmission events has implications not only for the recipient(s) experiencing infection, but also other recipients of organs or tissues from the same donor who may require additional testing or risk mitigation, as well as the broader organ transplant regulatory framework. This narrative review synthesizes data from published reports of symptomatic unexpected donor-derived infections in SOT recipients to provide clinicians with a systematic approach to the evaluation of undifferentiated illnesses that may be of donor origin. Key reasons to consider donor-derived infection include certain microbiologically proven infections in the recipient, especially early after transplant, characteristics of the donor or their management that suggest potential exposure to or infection with specific pathogens prior to organ procurement, and select clinical syndromes that occur in the post-transplant period. Syndromes for which expedited consideration and evaluation of donor-derived infection may be warranted include central nervous system infection, graft or perigraft complications developing in the absence of typical risk factors, and unexplained critical illness/sepsis syndrome in the early post-transplant period. When embarking on an investigation of a suspected donor-derived infection, clinicians should apply knowledge of the entire continuum of the organ procurement and transplant process to ensure unbiased and comprehensive data collection that will facilitate appropriate adjudication of these uncommon but high-consequence events.

Nebulized Micafungin Treatment for Scopulariopsis/Microascus Tracheobronchitis in Lung Transplant Recipients

Scopulariopsis/Microascus isolates cause infections with high mortality in lung transplant recipients. Treatment is challenging due to antimicrobial resistance. We describe two cases of Scopulariopsis/Microascus tracheobronchitis in lung transplant recipients successfully treated with nebulized micafungin. This antifungal was well tolerated and achieved high concentrations in epithelial lining fluid up to 14 h after nebulization without significant plasma concentrations. Nebulized micafungin may be a safe and effective option for the treatment of fungal tracheobronchitis.

First reported case of disseminated Microascus gracilis infection in a lung transplant patient

Microascus gracilis is a specie of the genus Microascus in the family of Microascaceae and has been isolated from lung. It has never been reported as the cause of disseminated infection in humans. Herein, we report a fatal case of disseminated Microascus gracilis infection in a 65-year-old man with a history of primary idiopathic pulmonary fibrosis, status-post bilateral lung transplant. His course was complicated by donor lung cultures positive for multiple organisms and persistent pleural effusions. Multiple lung biopsy and bronchial lavage specimens were negative for mold. Later, pleural fluid cultures grew M. gracilis confirmed by DNA sequencing. Despite aggressive antifungal treatment, the patient continued to deteriorate with altered mental status. Imaging showed scattered hemorrhagic and hypodense lesions in the brain. The patient eventually succumbed to his infections and a restricted autopsy was performed. Autopsy findings included multiple hemorrhagic foci and abscesses involving the whole brain. Numerous punctuate, tan-white circular lesions were on the endocardium and diffuse tan exudates covered the pericardium and lungs. Histologically, similar fungal organisms with septate branching hyphae and short chains of conidia were identified, along with hemorrhage, neutrophilic inflammation, and necrosis in the brain, pleura, peripheral parenchyma of lungs and heart. This is the first reported case of disseminated M. gracilis infection in an immunosuppressed human, indicating it can cause localized infections and disseminated infections. This case increases our awareness of such fatal opportunistic infections, particularly in lung transplant patients, and urges earlier aggressive prophylaxis, diagnosis, and treatment.

Current knowledge on the etiology and epidemiology of Scopulariopsis infections

Scopulariopsis is a common fungus in the environment, characterized by its intrinsic resistance to the available antifungal drugs. Around 70 cases of infection by this fungus have been described in the literature. Pulmonary and disseminated infections are the most common and their treatment is difficult; therefore, very diverse approaches have been taken, with varied results. A successful outcome has been reported in only a few cases, generally attributed to a multitreatment strategy combining medical and surgical procedures that ultimately led to the resection of the infected tissue if possible, identification of the mould, and an aggressive long-term antifungal therapy. Although most of the infections are caused by Scopulariopsis brevicaulis, a few other species have also been linked to these cases, although molecular evidence has not been proven for all of them. On this basis, more knowledge on the epidemiology, presentation, diagnosis, treatment, and prognosis of these unusual infections would improve their management. This review aims to compile the current data on Scopulariopsis infections.

Scopulariopsis/Microascus isolation in lung transplant recipients: A report of three cases and a review of the literature

The current knowledge of invasive Scopulariopsis/Microascus infection in lung transplantation has been derived from only four case reports. Although these fungi are uncommon compared with Aspergillus, they are highly resistant to the current antifungal agents, and the mortality is extremely high. To explore the risk factors, clinical manifestations, notable diagnostic characteristics and outcomes of positive Scopulariopsis/Microascus isolation in lung transplantation patients. We included all cases with positive Scopulariopsis/Microascus isolation from lower respiratory tracts or bronchial mucosa biopsies in our lung transplantation centre. Proven cases from the literature were added. Positive isolation occurred in 2% (3/157) in our centre. Four cases from the literature were added. The mortality could be considered as high as 80%, once the two cases of colonisation were excluded. The average interval between transplantation and positive isolation was 106 (19-131) days. A total of 57.1% of patients had experienced a combination of infection with Aspergillus or other fungi as well as long-term azole antifungal agent treatment before the positive isolation, which may be possible risk factors. The combination of micafungin, posaconazole and terbinafine may be an effective treatment. The peak time of positive isolation was consistent with that of some opportunistic pathogens, and the possible risk factors were the infection of other fungi as well as prior long-term azole antifungal administration. In addition to its high mortality, Scopulariopsis/Microascus was also highly resistant to common antifungal agents and the combination of two or three drugs for therapy was recommended.

Dermatologic considerations in pediatric transplant recipients

PURPOSE OF REVIEW

The pediatric transplant patient population is growing as the number of solid organ transplants and indications for hematopoietic stem cell transplant increase. Understanding cutaneous sequelae of pediatric transplant and treatment strategies to manage these outcomes is vital to the care of these patients.

RECENT FINDINGS

Important work in the past year enhances our understanding of the cutaneous implications of pediatric transplantation, including further work in areas of malignancy, infection, and graft versus host disease as well as newly reported risks.

SUMMARY

This review highlights recent developments in the recognition and management of dermatological complications of pediatric transplant that will be useful for the practicing pediatrician or dermatologist.

Fatal Scopulariopsis brumptii in a Pediatric Immunocompromised Host

Scopulariopsis species cause a broad range of disease, from superficial skin infections to often fatal disseminated disease in the immunocompromised that is refractory to standard antifungal treatment. This report describes the first case of fatal disseminated Scopulariopsis brumptii in a pediatric patient with hyper-IgM syndrome status post bone marrow transplant.

Rapid Assays for Specific Detection of Fungi of Scopulariopsis and Microascus Genera and Scopulariopsis brevicaulis Species

Purpose

Fungi of Scopulariopsis and Microascus genera cause a wide range of infections, with S. brevicaulis being the most prevalent aetiological agent of mould onychomycosis. Proper identification of these pathogens requires sporulating culture, which considerably delays the diagnosis. So far, sequencing of rDNA regions of clinical isolates has produced ambiguous results due to the lack of reference sequences in publicly available databases. Thus, there is a clear need for the development of new molecular methods that would provide simple, rapid and highly specific identification of Scopulariopsis and Microascus species. The objective of this study was to develop simple and fast assays based on PCR and real-time PCR for specific detection of fungi from Scopulariopsis and Microascus genera, and separately, S. brevicaulis species.

Methods

On the basis of alignment of β-tubulin gene sequences, Microascus/Scopulariopsis-specific primers were designed and S. brevicaulis-specific primers were reevaluated. DNA from cultured fungal isolates, extracted in a two-step procedure, was used in Microascus/Scopulariopsis-specific and S. brevicaulis-specific PCR and real-time PCR followed by electrophoresis or melting temperature analysis, respectively.

Results

The specificity of the assays was confirmed, as positive results were obtained only for Scopulariopsis spp. and Microascus spp. isolates tested in Microascus/Scopulariopsis-specific assay, and only for S. brevicaulis and S. koningii (syn. S. brevicaulis) isolates in a S. brevicaulis-specific assay, respectively, and no positive results were obtained neither for other moulds, dermatophytes, yeast-like fungi, nor for human DNA.

Conclusions

The developed assays enable fast and unambiguous identification of Microascus spp. and Scopulariopsis spp. pathogens.

Virulence and Resistance to Antifungal Therapies of Scopulariopsis Species

Scopulariopsisis an emerging opportunistic fungus characterized by its high resistance to antifungal therapies. We have developed a murine model of disseminated infection in immunosuppressed animals by intravenous inoculation ofScopulariopsis brevicaulisandScopulariopsis brumptii, the most clinically relevant species, in order to evaluate their virulence and their responses to conventional antifungal treatments. Survival and tissue burden studies showed thatS. brumptiiwas more virulent thanS. brevicaulis The three drugs tested, liposomal amphotericin B, posaconazole, and voriconazole, prolonged the survival of mice infected withS. brumptii, but none showed efficacy againstS. brevicaulis The different therapies were only able to modestly reduce the fungal burden of infected tissue; however, in general, despite the high serum levels reached, they showed poor efficacy in the treatment of the infection. Unfortunately, the most effective therapy forScopulariopsisinfections remains unresolved.

Respiratory Failure due to Possible Donor-Derived Sporothrix schenckii Infection in a Lung Transplant Recipient

Background. De novo and donor-derived invasive fungal infections (IFIs) contribute to morbidity and mortality in solid organ transplant (SOT) recipients. Reporting of donor-derived IFIs (DDIFIs) to the Organ Procurement Transplant Network has been mandated since 2005. Prior to that time no systematic monitoring of DDIFIs occurred in the United States. Case Presentation. We report a case of primary graft dysfunction in a 49-year-old male lung transplant recipient with diffuse patchy bilateral infiltrates likely related to pulmonary Sporothrix schenckii infection. The organism was isolated from a bronchoalveolar lavage on the second day after transplantation. Clinical and radiographic responses occurred after initiation of amphotericin B lipid formulation. Conclusion. We believe that this was likely a donor-derived infection given the early timing of the Sporothrix isolation after transplant in a bilateral single lung transplant recipient. This is the first case report of sporotrichosis in a lung transplant recipient. Our patient responded well to amphotericin induction therapy followed by maintenance therapy with itraconazole. The implications of donor-derived fungal infections and Sporothrix in transplant recipients are reviewed. Early recognition and management of these fungi are essential in improving outcomes.

Invasive Microascus trigonosporus Species Complex Pulmonary Infection in a Lung Transplant Recipient

Because of the high incidence of morbidity and mortality associated with invasive fungal infections, antifungal prophylaxis is often used in solid organ transplant recipients. However, this prophylaxis is not universally effective and may contribute to the selection of emerging, resistant pathogens. Here we present a rare case of invasive infection caused by Microascus trigonosporus species complex in a human, which developed during voriconazole prophylaxis in a lung transplant recipient. Nebulized liposomal amphotericin B was used in addition to systemic therapy in order to optimize antifungal drug exposure; this regimen appeared to reduce the patient's fungal burden. Despite this apparent improvement, the patient's pulmonary status progressively declined in the setting of multiple comorbidities, ultimately leading to respiratory failure and death.