[Cutaneous mucormycosis caused by Rhizopus microsporus]

BACKGROUND

Mucormycosis are rare fungal infections occurring chiefly in the lung or the rhinocerebral compartment, particularly in patients with immunodeficiency or mellitus diabetes. We report the case of an elderly patient with cutaneous mucormycosis caused by Rhizopus microsporus.

PATIENTS AND METHODS

An 89-year-old man presented a skin lesion of the forearm rapidly becoming inflammatory and necrotic. The patient had been treated for 2months with oral corticosteroids for idiopathic thrombocytopenia. Histological and mycological examination of the skin biopsy revealed the presence of a filamentous fungus, R. microsporus. The outcome was unfavorable, despite prescription of high-dose liposomal amphotericin B.

DISCUSSION

Mucormycosis are infrequent opportunistic infections caused by angio-invasive fungi belonging to the Mucorales order. Cutaneous presentations are rare, and in rare cases the species R. microsporus is isolated in clinical samples. Diagnosis is based on histological examination highlighting the characteristic mycelium within infected tissue, together with ex vivo mycological identification using morphological and molecular methods. Treatment consists of liposomal amphotericin B combined with debridement surgery.

CONCLUSION

R. microsporus is a marginal fungal species rarely isolated in clinical practice, and even less in dermatology departments. This clinical case report highlights the severity of infection with this fungus, particularly in the absence of early surgery.

Successful isavuconazole salvage therapy in a patient with invasive mucormycosis

A 45-year-old male with rhinocerebral mucormycosis (Rhizopus oryzae), refractory to liposomal amphotericin B and posaconazole, received isavuconazole salvage therapy. Initial isavuconazole plasma and tissue levels were 0.76-0.86 μg/mL and 1.09-1.38 μg/g. Plasma levels increased to 1.3-3.24 μg/mL with reduced comedication. Isavuconazole was well tolerated, and the patient has remained disease-free 24 months post-antifungal therapy.

Mucormycosis in two community hospitals and the role of infectious disease consultation: a case series

BACKGROUND

Mucorales are ubiquitous filamentous fungi that can cause a devastating, invasive infection. This order has become an increasingly important pathogen during the last two decades, due to the dramatic increase in patients with predisposing factors. The aim of this retrospective study was to report the clinical characteristics, therapeutic options, and outcomes of patients diagnosed with mucormycosis in community hospitals in Amarillo, Texas, and to reflect on the role of infectious disease (ID) physicians in managing this potentially life-threatening problem.

PATIENTS AND METHODS

This was a retrospective chart review of patients hospitalized with mucormycosis in two community hospitals in Amarillo between January 1, 2001 and December 31, 2011.

RESULTS

Ten patients were diagnosed with mucormycosis during the study period, with a mean age of 58.8 years. There were five cases of pulmonary infection, two cases of cutaneous infection, two cases of rhinocerebral infection, and one case of gastrointestinal infection. Poorly controlled diabetes was the most common risk factor, identified in six patients, followed by hematological malignancy, immunosuppression, and trauma. ID physicians were consulted in all cases, albeit late in some cases. Nine patients received antifungal therapy, and five patients received surgical debridement. Lipid formulations of amphotericin B were prescribed for eight patients, used alone in two cases, and combined with caspofungin and posaconazole in one and five cases, respectively. One patient was treated with posaconazole alone. Eight patients were discharged from the hospital alive. The mortality rate at 6-month follow-up was 40%.

CONCLUSION

Mucormycosis is an emerging fungal infection that continues to carry significant morbidity and mortality. At-risk patient populations are on the rise, and include those with poorly controlled diabetes mellitus. Early diagnosis, in consultation with an ID physician, and an aggressive combined approach with surgical debridement and combined antifungal therapy is pivotal in improving patients' outcomes.

Risk factors for mortality in patients with invasive mucormycosis

BACKGROUND

Mucormycosis is an uncommon and life-threatening fungal infection. The clinical predictors of outcome were evaluated in patients with invasive mucormycosis.

MATERIALS AND METHODS

We retrospectively reviewed histologically proven cases of invasive mucormycosis in our institution from 1996 to 2012.

RESULTS

A total of 64 patients were analyzed. The median age was 59 years (interquartile range [IQR], 50-67), and 32 patients (50%) were male. The most common underlying diseases were diabetes mellitus (67%), hematologic malignancy (22%), and solid cancer (19%). The most common infection sites were the rhino-orbito-cerebral area (56%) and the lungs (31%). The 180-day all-cause mortality was 33%. Disseminated infection was associated with increased mortality (hazard ratio [HR]: 169.74, 95% confidence interval [CI]: 6.41 to 4492.64; P = 0.002). Pulmonary infection (HR: 0.08, 95% CI: 0.01 to 0.66; P = 0.02) and complete surgical removal of infected tissue (HR: 0.12, 95% CI: 0.02 to 0.64; P = 0.01) were associated with decreased mortality.

CONCLUSIONS

These results suggest that patients with mucormycosis had a lower risk of mortality if they developed a pulmonary infection, rather than a disseminated infection and with complete debridement of infected tissue.

Epidemiology and treatment of mucormycosis

Mucormycosis is an uncommon but aggressive opportunistic fungal infection that afflicts patients with severe underlying immunosuppression, uncontrolled hyperglycemia and/or ketoacidosis, patients with iron overload resulting from frequent blood transfusions or blood disorders and occasionally healthy patients who are inoculated with fungal spores through traumatic injuries. The clinical presentation of mucormycosis is initially indistinguishable from other common infections, and if not diagnosed early and aggressively treated, it is almost always fatal. In this article we summarize recent changes in the epidemiology of mucormycosis, discuss diagnostic and clinical clues suggestive of the infection and provide a general strategy for managing the infection in the absence of data from well-controlled, prospective clinical trials.

Successful treatment of disseminated mucormycosis in a neutropenic patient with T-cell acute lymphoblastic leukaemia

Mucormycosis is a rare angioinvasive fungal infection, more commonly seen in immunosuppressed patients, with reported mortality rates of 95% in disseminated disease. We present a case report of a patient with T-cell acute lymphoblastic leukaemia who developed disseminated infection with mucormycosis (involving the pancreas, left occipital lobe, right lower lobe of lung, appendix and right kidney) after having completed induction and consolidation chemotherapy. Growth of Lichtheimia corymbifera was initially isolated following a right pleural tap with fungal elements identified repeatedly on subsequent pathology specimens. Following radical surgical debridement and concurrent treatment with combination antifungal therapy, the patient survived. This case demonstrates that aggressive multisite surgical de-bulking of disseminated fungal foci, in conjunction with combination antifungal therapy and reversal of immunosuppression, can result in survival despite the grave prognosis associated with disseminated mucormycosis.

Risk factors for early mortality in haematological malignancy patients with pulmonary mucormycosis

Pulmonary mucormycosis (PM) is a life-threatening opportunistic mycosis with a variable clinical evolution and few prognostic markers for outcome assessment. Several clinical risk factors for poor outcome present at the diagnosis of PM were analyzed in 75 consecutive hematology patients from 2000-2012. Significant variables (P < 0.1) were entered into a multivariate Cox-proportional hazard regression model adjusting for baseline APACHE II to identify independent risk factors for mortality within 28 days. Twenty-eight of 75 patients died within 4-week follow up. A lymphocyte count < 100/mm³ at the time of diagnosis (adjusted hazard ratio 4.0, 1.7-9.4, P = 0.01) and high level of lactate dehydrogenase (AHR 3.7, 1.3-10.2, P = 0.015) were independent predictors along with APACHE II score for 28-day mortality. A weighted risk score based on these 3 baseline variables accurately identified non-surviving patients at 28 days (area under the receiver-operator curve of 0.87, 0.77-0.93, P < 0.001). A risk score > 22 was associated with 8-fold high rates of mortality (P < 0.0001) within 28 days of diagnosis and median survival of 7 days versus ≥28 days in patients with risk scores ≤22. We found that APACHE II score, severe lymphocytopenia and high LDH levels at the time of PM diagnosis were independent markers for rapid disease progression and death.

Mucormycosis-associated intracranial hemorrhage

Rhinoorbitocerebral mucormycosis is a devastating infection being increasingly recognized in immunocompromised hosts and carries poor prognosis. Early recognition and treatment are critical in order to improve clinical outcomes and decrease the development of complications. Fatal cerebral infarctions have been described in patients with rhinoorbitocerebral mucormycosis, likely due to the thrombotic occlusion of the affected blood vessels directly invaded by this aggressive mycotic infection. We report a patient that presented with aplastic anemia, subsequently complicated by systemic mucormycosis, which generated reactive plasmacytosis, and developed intracranial infarction and hemorrhage.

[Iron and invasive fungal infection]

Iron is an essential factor for both the growth and virulence of most of microorganisms. As a part of the innate (or nutritional) immune system, mammals have developed different mechanisms to store and transport this element in order to limit free iron bioavailability. To survive in this hostile environment, pathogenic fungi have specific uptake systems for host iron sources, one of the most important of which is based on the synthesis of siderophores-soluble, low-molecular-mass, high-affinity iron chelators. The increase in free iron that results from iron-overload conditions is a well-established risk factor for invasive fungal infection (IFI) such as mucormycosis or aspergillosis. Therefore, iron chelation may be an appealing therapeutic option for these infections. Nevertheless, deferoxamine -the first approved iron chelator- paradoxically increases the incidence of IFI, as it serves as a xeno-siderophore to Mucorales. On the contrary, the new oral iron chelators (deferiprone and deferasirox) have shown to exert a deleterious effect on fungal growth both in vitro and in animal models. The present review focuses on the role of iron metabolism in the pathogenesis of IFI and summarises the preclinical data, as well as the limited clinical experience so far, in the use of new iron chelators as treatment for mucormycosis and invasive aspergillosis.

Efficacy of liposomal amphotericin B and posaconazole in intratracheal models of murine mucormycosis

Mucormycosis is a life-threatening fungal infection almost uniformly affecting diabetics in ketoacidosis or other forms of acidosis and/or immunocompromised patients. Inhalation of Mucorales spores provides the most common natural route of entry into the host. In this study, we developed an intratracheal instillation model of pulmonary mucormycosis that hematogenously disseminates into other organs using diabetic ketoacidotic (DKA) or cyclophosphamide-cortisone acetate-treated mice. Various degrees of lethality were achieved for the DKA or cyclophosphamide-cortisone acetate-treated mice when infected with different clinical isolates of Mucorales. In both DKA and cyclophosphamide-cortisone acetate models, liposomal amphotericin B (LAmB) or posaconazole (POS) treatments were effective in improving survival, reducing lungs and brain fungal burdens, and histologically resolving the infection compared with placebo. These models can be used to study mechanisms of infection, develop immunotherapeutic strategies, and evaluate drug efficacies against life-threatening Mucorales infections.

[Mixed invasive fungal infection due to Rhizomucor pusillus and Aspergillus niger in an immunocompetent patient]

BACKGROUND

Mucormycosis infections are rare in immunocompetent patients, and very few cases of mucormycosis associated with aspergillosis in non-haematological patients have been reported.

CASE REPORT

A 17-year-old male, immunocompetent and without any previously known risk factors, was admitted to hospital due to a seizure episode 11 days after a motorcycle accident. He had a complicated clinical course as he had a mixed invasive fungal infection with pulmonary involvement due to Aspergillus niger and disseminated mucormycosis due to Rhizomucor pusillus (histopathological and microbiological diagnosis in several non-contiguous sites). He was treated with liposomal amphotericin B for 7 weeks (total cumulative dose >10 g) and required several surgical operations. The patient survived and was discharged from ICU after 5 months and multiple complications.

CONCLUSIONS

Treatment with liposomal amphotericin B and aggressive surgical management achieved the eradication of a mixed invasive fungal infection. However, we emphasise the need to maintain a higher level of clinical suspicion and to perform microbiological techniques for early diagnosis of invasive fungal infections in non-immunocompromised patients, in order to prevent spread of the disease and the poor prognosis associated with it.

[Hemoptysis complicating bronchopulmonary mucormycosis in a diabetic patient]

INTRODUCTION

Mucormycosis are the fungal infections caused by emerging ubiquitous filamentous fungi classified as zygometes and order as mucorales. They occur mainly in immunosuppressed patients and diabetics. The onset of hemoptysis, in this context, may rapidly become life-threatening.

OBSERVATION

We report the case of a man of 83 years, Caribbean with a history of non-insulindependent diabetes and HTLV1 seropositive. At admission he presented with fever, cough and cachexia. Chest X-ray revealed a snapshot of excavation within alveolar consolidation. Endoscopy showed a mucopurulent plug obstructing lingula. The histological appearance of bronchial biopsies was in favor of mucormycosis. A combined treatment with liposomal amphotericin B and posaconasole was implemented, but the occurrence of abundant hemoptysis led us to make a left upper lobectomy. Finally, the outcome was favorable and the patient was discharged after hospitalization of 56 days.

CONCLUSION

A medicosurgical treatment during mucormycosis complicating bronchopulmonary hemoptysis not controlled by medical treatment alone seems to offer an effective therapeutic strategy.

[Clinical and radiological aspects of mucormycosis]

Mucormycosis is an infection caused by filamentous fungi of the Mucorales order. The predisposing factors are mostly diabetic ketoacidosis and severe immunosuppressive conditions such as prolonged neutropenia, steroid or T-cell suppressor therapy, solid organ transplantation or allogeneic hematopoietic stem cell transplantation. Mucormycosis can also occur in immunocompetent patients, especially after trauma, burns or direct inoculation of the fungi (e.g. intravenous drug abuse). The most frequently targeted primary sites of infection are sinuses with a rapid spread to the adjacent tissues including the brain, the lower respiratory tract, the digestive tract and the skin. Mucorales are able to invade the vessels causing hematogenous dissemination, vascular thrombosis and, ultimately, necrosis of the lesions. Clinical and radiological aspects are similar to those observed in other invasive filamentous fungi infections such as invasive aspergillosis, fusariosis or scedosporiosis. CT-scan or MRI are mandatory to assess the extension of the lesions. The diagnosis remains difficult and is often delayed resulting in a poor outcome.

[Rhino-orbito-cerebral mucormycosis, surgical treatment, state of the art]

Rhino-orbito-cerebral mucormycoses constitute a severe fungal infection. These infections mostly arise in immunosuppressed patients. The surgery aiming at resecting necrosed hurts showed its interest in term of survival for lung and cutaneous mucormycosis. However, treatment of rhino-orbito-cerebral location of mucormycosis is not well defined. Transnasal endoscopic surgery allows local control of the disease, better post-operative outcomes than transfacial approaches and less sequelae. However, transfacial approaches are sometimes necessary to allow cutaneous resection or exenteration, the indications of which still remain controversial. The retrospective study of 22 patients with mucormycosis allowed to show that radical surgical treatment allowed local control of the disease with an improved survival. Further prospective studies (PHRC MICCA, current) are required to standardize the management of this rare but potentially lethal pathology.

Quantitative polymerase chain reaction detection of circulating DNA in serum for early diagnosis of mucormycosis in immunocompromised patients

BACKGROUND

The aim of our study was to assess the detection of circulating DNA from the most common species of Mucorales for early diagnosis of mucormycosis in at-risk patients.

METHODS

We retrospectively evaluated a combination of 3 quantitative polymerase chain reaction (qPCR) assays using hydrolysis probes targeting Mucor/Rhizopus, Lichtheimia (formerly Absidia), and Rhizomucor for circulating Mucorales detection. Serial serum samples from 10 patients diagnosed with proven mucormycosis (2-9 samples per patient) were analyzed.

RESULTS

No cross-reactivity was detected in the 3 qPCR assays using 19 reference strains of opportunistic fungi, and the limit of detection ranged from 3.7 to 15 femtograms/10 µL, depending on the species. DNA from Mucorales was detected in the serum of 9 of 10 patients between 68 and 3 days before mucormycosis diagnosis was confirmed by histopathological examination and/or positive culture. All the qPCR results were concordant with culture and/or PCR-based identification of the causing agents in tissue (Lichtheimia species, Rhizomucor species, and Mucor/Rhizopus species in 4, 3, and 2 patients, respectively). Quantitative PCR was negative in only 1 patient with proven disseminated mucormycosis caused by Lichtheimia species.

CONCLUSION

Our study suggests that using specific qPCR targeting several species of Mucorales according to local ecology to screen at-risk patients could be useful in a clinical setting. The cost and efficacy of this strategy should be evaluated. However, given the human and economic cost of mucormycosis and the need for rapid diagnosis to initiate prompt directed antifungal therapy, this strategy could be highly attractive.

Liposomal amphotericin B and surgery as successful therapy for pulmonary Lichtheimia corymbifera zygomycosis in a pediatric patient with acute promyelocytic leukemia on antifungal prophylaxis with posaconazole

Pulmonary zygomycosis, also referred to as mucormycosis, is a fungal infection of lungs caused by fungi of the order Mucorales in the class of Zygomycetes. It is usually associated with high morbidity and mortality. Here, we report the case of a 14-year-old girl with pediatric acute promyelocytic leukemia (APL) on antifungal prophylaxis with posaconazole, who developed pulmonary Lichtheimia corymbifera (formerly Absidia corymbifera) zygomycosis. She was successfully treated by means of liposomal amphotericin B (L-AmB) and surgery. To our knowledge, this is the first published report on pediatric APL and pulmonary zygomycosis in the English language literature. At present, the patient is in complete remission of her APL and without any signs of recurrence of zygomycosis. This report suggests that efficient diagnostics, increased physician awareness, and reliance on adjunctive surgical therapy can result in a favorable outcome of pulmonary zygomycosis in immunocompromised children with hematological malignancies.

Wound infection caused by Lichtheimia ramosa due to a car accident

A 32-year-old immunocompetent man sustained severe traumas contaminated with organic material due to a car accident. An infection caused by Lichtheimia ramosa at the site of contamination was early diagnosed and cured by multiple surgical debridement and daily cleansing with antiseptic solution only.

Emerging invasive fungal diseases in transplantation

Invasive fungal infections continue to be a major cause of morbidity and mortality in severely immunocompromised transplant patients. Although Candida spp. and Aspergillus spp. represent the majority of identified pathogens, other fungi have become increasingly prevalent among this patient population. Diagnosis and treatment of invasive fungal infections remain a challenge in transplant medicine despite recent major advances. In this review, we will emphasize emerging topics in invasive fungal infections in transplantations that occurred in 2011-2012. The current literature was reviewed to synthesize new trends in epidemiology, recent outbreaks, clinical findings, and advances in diagnostic and therapeutic resources.

Diagnosis and treatment of mucormycosis in patients with hematological malignancies: guidelines from the 3rd European Conference on Infections in Leukemia (ECIL 3)

Mucormycosis is an emerging cause of infectious morbidity and mortality in patients with hematologic malignancies. However, there are no recommendations to guide diagnosis and management. The European Conference on Infections in Leukemia assigned experts in hematology and infectious diseases to develop evidence-based recommendations for the diagnosis and treatment of mucormycosis. The guidelines were developed using the evidence criteria set forth by the American Infectious Diseases Society and the key recommendations are summarized here. In the absence of validated biomarkers, the diagnosis of mucormycosis relies on histology and/or detection of the organism by culture from involved sites with identification of the isolate at the species level (no grading). Antifungal chemotherapy, control of the underlying predisposing condition, and surgery are the cornerstones of management (level A II). Options for first-line chemotherapy of mucormycosis include liposomal amphotericin B and amphotericin B lipid complex (level B II). Posaconazole and combination therapy of liposomal amphotericin B or amphotericin B lipid complex with caspofungin are the options for second line-treatment (level B II). Surgery is recommended for rhinocerebral and skin and soft tissue disease (level A II). Reversal of underlying risk factors (diabetes control, reversal of neutropenia, discontinuation/taper of glucocorticosteroids, reduction of immunosuppressants, discontinuation of deferroxamine) is important in the treatment of mucormycosis (level A II). The duration of antifungal chemotherapy is not defined but guided by the resolution of all associated symptoms and findings (no grading). Maintenance therapy/secondary prophylaxis must be considered in persistently immunocompromised patients (no grading).

Population pharmacokinetics of conventional and intermittent dosing of liposomal amphotericin B in adults: a first critical step for rational design of innovative regimens

There is increased interest in intermittent regimen of liposomal amphotericin B, which may facilitate use in ambulatory settings. Little is known, however, about the most appropriate dosage and schedule of administration. Plasma pharmacokinetic data were acquired from 30 patients receiving liposomal amphotericin B for empirical treatment of suspected invasive fungal infection. Two cohorts were studied. The first cohort received 3 mg of liposomal amphotericin B/kg of body weight/day; the second cohort received 10 mg of liposomal amphotericin B/kg at time zero, followed by 5 mg/kg at 48 and 120 h. The levels of liposomal amphotericin B were measured by high-pressure liquid chromatography (HPLC). The pharmacokinetics were estimated by using a population methodology. Monte Carlo simulations were performed. D-optimal design was used to identify maximally informative sampling times for both conventional and intermittent regimens for future studies. A three-compartment pharmacokinetic model best described the data. The pharmacokinetics for both conventional and intermittent dosing were linear. The estimates for the mean (standard deviation) for clearance and the volume of the central compartment were 1.60 (0.85) liter/h and 20.61 (15.27) liters, respectively. Monte Carlo simulations demonstrated considerable variability in drug exposure. Bayesian estimates for clearance and volume increased in a linear manner with weight, but only the former was statistically significant (P = 0.039). D-optimal design provided maximally informative sampling times for future pharmacokinetic studies. The pharmacokinetics of a conventional and an intermittently administered high-dose regimen liposomal amphotericin B are linear. Further pharmacokinetic-pharmacodynamic preclinical and clinical studies are required to identify safe and effective intermittent regimens.

"We are what we eat!" Invasive intestinal mucormycosis: A case report and review of the literature

Gastrointestinal mucormycosis is an uncommon, life-threatening, angioinvasive infection with only one previous report of disease involving the jejunum. We present a case of invasive jejunal mucormycosis and review the literature, highlighting the rare clinical presentation and the value of molecular diagnostic methods. Given the global increase in patient populations at risk of mucormycosis, clinicians need to maintain a high index of suspicion and perform timely and appropriate evaluation to improve patient outcome.

Lichtheimia species exhibit differences in virulence potential

Although the number of mucormycosis cases has increased during the last decades, little is known about the pathogenic potential of most mucoralean fungi. Lichtheimia species represent the second and third most common cause of mucormycosis in Europe and worldwide, respectively. To date only three of the five species of the genus have been found to be involved in mucormycosis, namely L. corymbifera, L. ramosa and L. ornata. However, it is not clear whether the clinical situation reflects differences in virulence between the species of Lichtheimia or whether other factors are responsible. In this study the virulence of 46 strains of all five species of Lichtheimia was investigated in chicken embryos. Additionally, strains of the closest-related genus Dichotomocladium were tested. Full virulence was restricted to the clinically relevant species while all strains of L. hyalospora, L. sphaerocystis and Dichotomocladium species were attenuated. Although virulence differences were present in the clinically relevant species, no connection between origin (environmental vs clinical) or phylogenetic position within the species was observed. Physiological studies revealed no clear connection of stress resistance and carbon source utilization with the virulence of the strains. Slower growth at 37°C might explain low virulence of L. hyalospora, L. spaherocystis and Dichotomocladium; however, similarly slow growing strains of L. ornata were fully virulent. Thus, additional factors or a complex interplay of factors determines the virulence of strains. Our data suggest that the clinical situation in fact reflects different virulence potentials in the Lichtheimiaceae.

Mucormycosis after allogeneic haematopoietic stem cell transplantation: a French Multicentre Cohort Study (2003-2008)

We conducted a nationwide retrospective study to evaluate clinical characteristics and outcome of mucormycosis among allogeneic haematopoietic stem cell transplant recipients. Twenty-nine patients were diagnosed between 2003 and 2008. Mucormycosis occurred at a median of 225 days after allogeneic haematopoietic stem cell transplant, and as a breakthrough infection in 23 cases. Twenty-six patients were receiving steroids, mainly for graft-versus-host disease treatment, while ten had experienced a prior post-transplant invasive fungal infection. Twenty-six patients received an antifungal treatment; surgery was performed in 12. Overall survival was 34% at 3 months and 17% at 1 year.