Mucormycosis as a rare cause of severe gastrointestinal bleeding after multivisceral transplantation

Epidemiology, Clinical Manifestations, and Outcome of Mucormycosis in Solid Organ Transplant Recipients: A Systematic Review of Reported Cases

Mucormycosis is an emerging disease primarily affecting the immunocompromised host, but scarce evidence is available for solid organ transplant recipients (SOTRs). We systematically reviewed 183 cases occurring in SOTRs, exploring epidemiology, clinical characteristics, causative pathogens, therapeutic approaches, and outcomes. Kidney transplants accounted for half of the cases, followed by heart (18.6%), liver (16.9%), and lung (10.4%). Diagnosis showed a dichotomous distribution, with 63.7% of cases reported within 100 days of transplantation and 20.6% occurring at least 1 year after transplant. The 90-day and 1-year mortality rates were 36.3% and 63.4%, respectively. Disseminated disease had the highest mortality at both time points (75% and 93%). Treatment with >3 immunosuppressive drugs showed a significant impact on 90-day mortality (odds ratio [OR], 2.33; 95% CI, 1.02-5.66; P = .0493), as did a disseminated disease manifestation (OR, 8.23; 95% CI, 2.20-36.71; P = .0027) and the presence of diabetes (OR, 2.35; 95% CI, 1.01-5.65; P = .0497). Notably, prophylaxis was administered to 12 cases with amphotericin B. Further investigations are needed to validate these findings and to evaluate the potential implementation of prophylactic regimens in SOTRs at high risk.

Case report: The clinical utility of metagenomic next-generation sequencing in mucormycosis diagnosis caused by fatal Lichtheimia ramosa infection in pediatric neuroblastoma

Lichtheimia ramosa (L. ramosa) is an opportunistic fungal pathogen of the order Mucorales that may result in a rare but serious mucormycosis infection. Mucormycosis could be angioinvasive, causing thrombosis and necrosis in the nose, brain, digestive tract, and respiratory tract. The infection is highly lethal, especially in immunocompromised hosts, and the incidence has been on the rise. However, due to its relatively low incidence in pediatric population and the challenges with diagnosis, the awareness and management experience for pediatric mucormycosis are extremely limited, which might lead to poor outcomes. In this study, we comprehensively reviewed the course of a fatal rhinocerebral mucormycosis case in a pediatric neuroblastoma patient receiving chemotherapy. Due to a lack of awareness of the infection, the standard care of amphotericin B treatment was delayed and not administered until the identification of L. ramosa by metagenomic next-generation sequencing (mNGS)-based pan-pathogen detection of the patient's peripheral blood sample. We also reviewed the literature on L. ramosa infection cases reported worldwide between 2010 and 2022, with an analysis of clinical manifestation, prognosis, and epidemiological data. Our study not only highlighted the clinical value of comprehensive mNGS in rapid pathogen detection but also raised awareness of recognizing lethal fungal infection early in immunocompromised hosts including pediatric cancer patients.

Rhizomucor hepatosplenic abscesses in a patient with renal and pancreatic transplantation

Fungal infections are generally observed in immunosuppressed patients only, with a diagnostic challenge due to non-specific symptoms. For this reason, appropriate management may be delayed. This case report concerns a 36-year-old man with history of pancreas and kidney transplantation. He had chemotherapy for post-transplant B-cell lymphoma and presented with left upper abdominal pain and fever. Multiple investigations led to a final diagnosis of disseminated abdominal mucormycosis with multiple Rhizomucor abscesses in the liver, spleen and kidney transplant. Treatment was antifungal therapy and laparotomy with splenectomy, wedge resection of two fungal abscesses in segments II and IVb, and segmental left colic resection.

First Case of Rhinocerebral Mucormycosis Caused by Lichtheimia ornata, with a Review of Lichtheimia Infections

BACKGROUND

Lichtheimia species are emerging opportunistic fungal pathogens in the Mucorales, causing serious skin and respiratory infections in immunocompromised patients. Established agents are Lichtheimia corymbifera and L. ramosa, while L. ornata is a novel agent. Available data on a species-specific analysis of Lichtheimia infections are limited.

METHODS

The first case of a fatal rhino-orbital-cerebral infection in a hematopoietic stem cell transplantation recipient caused by L. ornata is reported; the agent was identified by sequencing the ITS ribosomal region. We reviewed the literature on mucormycosis due to Lichtheimia species between 2009 and 2018, with an analysis of risk factors and epidemiological and clinical data.

RESULTS

In addition to our Lichtheimia ornata case, 44 cases of human Lichtheimia were analyzed. Lichtheimia predominated in Europe (68.2%), followed by Asia (16%), and Africa (9%). The most common underlying condition was hematological malignancy (36.3%), followed by trauma/major surgery (27.3%), while diabetes mellitus was rare (11.4%). Site of infection was mostly skin and soft tissues (45.5%) and lung (25%), while relatively few cases were disseminated (13.6%) or rhinocerebral (11.4%). Mortality (36.4%) was mainly due to disseminated and rhinocerebral infections.

CONCLUSION

In contrast to Rhizopus, the most common agent of mucormycosis recorded in patients with diabetes mellitus, Lichtheimia infections were primarily associated with hematological malignancies and major skin barrier damage. Given the fact that classical rhinocerebral mucormycosis remains difficult to treat, independent of causative species, timely application of amphotericin B accessory to debridement may be required for patient survival.

Successful Treatment of Intestinal Mycosis Caused by a Simultaneous Infection with Lichtheimia ramosa and Aspergillus calidoustus

A 53-year-old woman was hospitalized due to septic shock after developing pneumococcal pneumonia after undergoing esophageal cancer surgery. Her transverse colon became perforated after receiving antimicrobial chemotherapy; therefore, emergency subtotal colectomy was performed. Fungi detected in both her colon tissue and a drainage sample indicated intestinal mucormycosis. Early intensive treatment with high-dose liposomal amphotericin B was successful, and she was subsequently discharged from the hospital. The fungal isolates were identified to be Lichtheimia ramosa and Aspergillus calidoustus via gene sequencing using panfungal primers as well as species-specific primers against elongation factor 1 and beta-tubulin for detecting Lichtheimia and Aspergillus, respectively.

Late recurrent bleeding episodes from duodenojejunostomy after pancreas transplantation

In response to a number of late, repetitive bleeding episodes from the site of the enteric anastomosis, we herein analyze the clinical courses and etiologies of 379 consecutively performed pancreas transplants between January 2000 and December 2016. Duodenojejunostomies for enteric drainage were performed at the upper jejunum in a side to side, double layer fashion. Five patients (1.3%) developed recurrent late hemorrhagic episodes originating from the graft duodenal anastomosis. Bleeding from the anastomotic site was associated with hematochezia, hemodynamic instability and decrease in serum hemoglobin. Mean onset was 6.4(±2.8) years after transplantation. Bleeding was recurrent (mean 5.2 ± 2.6) and required 9(±2.5) interventions. Hypervascularization, mucosal vulnerability, and bleeding at the site of the enteric anastomosis could be identified in all cases. In four patients, the enteric pancreas anastomosis was resected and a new duodenojejunostomy was performed. No pancreas graft loss occurred due to bleeding. In two patients, hepatic cirrhosis and portal hypertension were identified, one patient had a liver fibrosis as putative cause for the repetitive bleeding episodes. Late anastomotic hemorrhage is a rare but severe complication following pancreas transplantation. The treatment is challenging and includes endoscopy, interventional radiology, and surgery. Hepatic conditions with an increased portal pressure may be the underlying cause.

Total Gastric Necrosis Due to Mucormycosis: A Rare Case of Gastric Perforation

Patient: Female, 52

Final Diagnosis: Gastric mucormycosis

Symptoms: Sepsis • surgical abdomen

Medication: Liposomal amphotericine b

Clinical Procedure: Total gastrectomy

Specialty: Surgery

Mucormycosis: an unusual cause of gastric perforation and severe bleeding in immunocompetent patients

Mucormycosis is a rare and often fatal opportunistic infection that especially occurs in immunocompromised patients. Primary gastrointestinal infection is uncommon and accounts for only approximately 7% of all cases of mucormycosis but it is associated with an 85% mortality rate due to perforation and massive bleeding. Very few cases of gastrointestinal mucormycosis in an immunocompetent host have been reported. We describe a case of gastric necrosis and massive bleeding due to fulminant invasive mucormycosis.

Gastrointestinal Zygomycosis Masquerading as Acute Appendicitis

Zygomycosis is a rare invasive opportunistic fungal infection that occurs in the setting of hematologic malignancies, chemotherapy-induced neutropenia, and immunosuppressive therapies. We report the first case of disseminated appendiceal zygomycosis due to Absidia spp. in a neutropenic patient who initially presented as acute appendicitis. A 63-year-old woman with acute myeloid leukemia presented as acute appendicitis while receiving induction chemotherapy and ultimately succumbed to overwhelming disseminated zygomycosis. Initial symptoms included loose stools and right lower abdominal pain unresponsive to broad-spectrum antibiotics. Clinical examination and cross-sectional imaging suggested acute appendicitis. The final diagnosis was established by histological evaluations of the ileocecectomy specimen, which showed angioinvasive fungal organisms within the necrotic appendiceal wall with characteristics typical of zygomycetes. Fungal cultures demonstrated Absidia spp. The patient was treated with amphotericin B but expired in the setting of fungal sepsis. A diagnosis of a fungal infection, including zygomycosis, should be considered in all chemotherapy-induced neutropenic patients who present with symptoms of acute appendicitis. A high index of clinical suspicion with prompt histologic and culture diagnosis of zygomycosis may reduce the high mortality and morbidity associated with zygomycosis of the gastrointestinal tract.

The genome sequence of four isolates from the family Lichtheimiaceae

This study reports the release of draft genome sequences of two isolates of Lichtheimia corymbifera and two isolates of L. ramosa. Phylogenetic analyses indicate that the two L. corymbifera strains (CDC-B2541 and 008-049) are closely related to the previously sequenced L. corymbifera isolate (FSU 9682) while our two L. ramosa strains CDC-B5399 and CDC-B5792 cluster apart from them. These genome sequences will further the understanding of intraspecies and interspecies genetic variation within the Mucoraceae family of pathogenic fungi.

Invasive mold infections in solid organ transplant recipients

Invasive mold infections represent an increasing source of morbidity and mortality in solid organ transplant recipients. Whereas there is a large literature regarding invasive molds infections in hematopoietic stem cell transplants, data in solid organ transplants are scarcer. In this comprehensive review, we focused on invasive mold infection in the specific population of solid organ transplant. We highlighted epidemiology and specific risk factors for these infections and we assessed the main clinical and imaging findings by fungi and by type of solid organ transplant. Finally, we attempted to summarize the diagnostic strategy for detection of these fungi and tried to give an overview of the current prophylaxis treatments and outcomes of these infections in solid organ transplant recipients.