Primary Cutaneous Mucormycosis Caused by Rhizomucor variabilis in an Immunocompetent Patient

Cutaneous Mucormycosis in an Immunocompetent Child following a Minor Skin Trauma

Cutaneous mucormycosis is a rare infection by the Zygomycetes class of fungi, which carries significant morbidity and mortality. While typically associated in patients with underlying immunocompromise (especially in the current era of COVID-19), it may also be seen in immunocompetent patients. We report a case of a healthy 4-year-old girl with acute right leg cellulitis and abscess formation, who required surgical debridement following poor response to antibiotic therapy and initial incision and drainage. Tissue histopathology returned cutaneous zygomycosis despite negative tissue cultures. At four-week follow-up, her wound was healed well. Clinicians should maintain a high degree of clinical suspicion for cutaneous mucormycosis given its potential for rapidly progressive and disseminated disease. Currently, the mainstay of diagnostic investigations is tissue histopathology, with a growing role for tissue fungal PCR. Treatment involves multidisciplinary management between surgeons and Infectious Diseases team to guide the role for surgical debridement and antifungal therapy.

A thermal adaptation landscape related to virulence in Mucor irregularis transcriptional profiles

OBJECTIVES

Our study aimed to better understand the different thermal adaptation in Mucor irregularis (M. irregularis) strains under high temperature and the involved virulence-related genes, and to offer more appropriate explanation for the diverse pathogenicity of M. irregularis in human infections.

METHODS

M. irregularis isolates were incubated at 30 and 35°C for Illumina HiSeq technology (RNA-seq), as well as the virulence difference detected through Galleria mellonella infection models. We verified their transcriptional profile with RT-PCR and analysed differentially expressed genes with GO and KEGG annotations.

RESULTS

All 25 isolates formed the biggest colonies at 28°C and did not grow at 37°C, while were differently inhibited at 22 and 35°C. Six selected M. irregularis displayed virulence in sync with their growth condition at high temperature. From the outcomes of RNA-seq, a total of 1559 differentially expressed genes (FC ≥ 2, FDR < 0.05) were obtained, of which 1021 genes were upregulated, and 538 genes were downregulated. Cell wall structure genes related to Ras-like and GH16 proteins, influx-efflux pumps consist of transmembrane proteins as ABC and MFS proteins, and metabolic genes as DGKɛ and Hsfs, seem to be essential in thermal adaptation and virulence of M. irregularis.

CONCLUSION

We found some common genes expressed at high temperature, while some others specifically related to M. irregularis isolates with different virulence and thermal adaptation. Further research of genes involved in the pathogenic process is needed for the development of potential targeted antifungal.

Vacuum-Assisted Closure and Skin Grafting Combined with Amphotericin B for Successful Treatment of an Immunocompromised Patient with Cutaneous Mucormycosis Caused by Mucor irregularis: A Case Report and Literature Review

Cutaneous mucormycosis caused by Mucor irregularis (M. irregularis) is a rare condition that typically occurs in immunocompetent patients. Herein, we describe an immunocompromised patient with cutaneous M. irregularis infection who was successfully treated with debridement combined with vacuum assisted closure (VAC) negative pressure technique and split-thickness skin grafting. We present this case owing to its complexity and rarity and the successful treatment with surgical therapy. A 58-year-old man presented to our hospital with a history of skin ulcers and eschar on the right lower leg since two months. He had been receiving methylprednisolone therapy for bullous pemphigoid that occurred five months prior to the present lesions. Histopathological examination of a right leg lesion showed broad, branching hyphae in the dermis. Fungal culture and subsequent molecular cytogenetic analysis identified the pathogen as M. irregularis. After admission, methylprednisolone was gradually tapered and systemic treatment with amphotericin B (total dose 615 mg) initiated along with others supportive therapies. However, the ulcers showed no improvement, and amphotericin B had to be discontinued owing to development of renal dysfunction. After extensive surgical debridement combined with VAC and skin grafting, his skin ulcers were healed; subsequent fungal cultures of the lesions were negative. The patient exhibited no signs of recurrence at 36-month follow-up. Twenty-six cases with M. irregularis-associated cutaneous mucormycosis in literature were reviewed.

Successful treatment of a patient with cutaneous co-infection caused by Mucor irregularis and Klebsiella pneumoniae

The authors report a rare case of primary cutaneous mucormycosis caused by Mucor irregularis and cutaneous Klebsiella pneumoniae infections in a 67-year-old Chinese woman. After the administration of liposomal amphotericin B combined with cefoperazone/sulbactam sodium, the patient recovered. Invasive fungal infection combined with cutaneous bacterial infection should receive attention.

Disfiguring Mucor irregularis Infection Cured by Amphotericin B and Itraconazole: A Case Report and Treatment Experience

We report a case of primary cutaneous mucormycosis caused by Mucor irregularis. A 52-year-old male farmer was presented to our hospital with a history of progressive nodule and plaque with ulceration on the face for two and a half years. Broad, aseptate hyphae were seen in direct KOH examination and biopsy. Fungal culture showed light yellow filamentous colonies. The rRNA sequencing revealed M. irregularis was the responsible fungus. Amphotericin B in gradually increasing dose and itraconazole were administered. When the cumulative dose of amphotericin B was 1500 mg, the skin lesion improved significantly with remaining scars on the face. Then, the patient received sequential oral itraconazole treatment for 8 months. There was no recurrence up to now through follow-ups.

Transcriptomic Analysis of Mucor irregularis Containing a Negative Single-Stranded RNA Mycovirus

The fungus Mucor irregularis is a causative agent of mucormycosis. The transcriptome analysis of the isolated M. irregularis strain C3B revealed the presence of an RNA polymerase domain of a negative-polarity RNA virus. In this work, we describe the gene ontology-based annotation of the Mucor irregularis transcriptome, which includes a putative RNA mycovirus.

Transcriptional profile of the human skin pathogenic fungus Mucor irregularis in response to low oxygen

Mucormycosis is one of the most invasive mycosis and has caused global concern in public health. Cutaneous mucormycosis caused by Mucor irregularis (formerly Rhizomucor variabilis) is an emerging disease in China. To survive in the human body, M. irregularis must overcome the hypoxic (low oxygen) host microenvironment. However, the exact molecular mechanism of its pathogenicity and adaptation to low oxygen stress environment is relatively unexplored. In this study, we used Illumina HiSeq technology (RNA-Seq) to determine and compare the transcriptome profile of M. irregularis CBS103.93 under normal growth condition and hypoxic stress. Our analyses demonstrated a series of genes involved in TCA, glyoxylate cycle, pentose phosphate pathway, and GABA shunt were down-regulated under hypoxic condition, while certain genes in the lipid/fatty acid metabolism and endocytosis were up-regulated, indicating that lipid metabolism was more active under hypoxia. Comparing the data with other important human pathogenic fungi such as Aspergillus spp., we found that the gene expression pattern and metabolism in responses to hypoxia in M. irregularis were unique and different. We proposed that these metabolic changes can represent a species-specific hypoxic adaptation in M. irregularis, and we hypothesized that M. irregularis could use the intra-lipid pool and lipid secreted in the infection region, as an extracellular nutrient source to support its hypoxic growth. Characterizing the significant differential gene expression in this species could be beneficial to uncover their role in hypoxia adaptation and fungalpathogenesis and further facilitate the development of novel targets in disease diagnosis and treatment against mucormycosis.

Successful Treatment by Surgery of a Primary Cutaneous Mucormycosis Caused by Mucor irregularis

We report a case of primary cutaneous mucormycosis caused by Mucor irregularis. A 66-year-old man was presented to our hospital with a history of gradually enlarging plaque on the right leg for about a year. The identification of pathogen based on the fungus morphology and DNA sequencing revealed M. irregularis as the responsible fungus for skin lesion. The lesion was removed incidentally by a surgery procedure, and no recrudescence was seen during a follow-up of 24-month observation.

The influence of the mating type on virulence of Mucor irregularis

Mucor irregularis is an emerging fungal pathogen that cause cutaneous infection and could cause death. However, little is known about its mechanism of pathogenesis. There is evidence suggesting virulence vary with mating types in fungi, including the Mucorales. Here, we characterized the mating type locus of M. irregularis and the mating type ratio of 17 clinical isolates in China. Genomic data indicated M. irregularis is heterothallic having two mating types – bearing either SexP or SexM allele. Also, we employed a mice model to study the inflammation and pathological effects of different mating types. The comparison of the inflammatory response, cytokine profiles and Th-1, Th-2 and Th-17 cells numbers in each mating type treated mice showed that the severity and disease progress were enhanced in (+) mating type treated mice. One (+/0) mutant strain, with multiple mutations at the mating locus, had defects in sexual mating ability but appeared to be more virulent than the (−) mating type. Although (+) mating type appeared to be more virulent, most of our clinical isolates presented belonged to (−) mating type. Our findings support the involvement of MAT genes in sexual fertility, and the influence of mating type on the severity of cutaneous infection.

Mucormycosis or extranodal natural killer/T cell lymphoma, similar symptoms but different diagnosis

Facial mucormycosis and extranodal natural killer/T cell lymphoma (NK/TCL) are characterized by facial progressive swelling, ulceration and destruction. Patient one was a 58-year-old woman, who had typical clinical-pathological symptoms of tumor. She was hospitalized in order to remove the tumor. But the diagnosis turned out to be primary mucor infection, which was corrected by positive tissue culture and fungal elements in histology. She was also diagnosed with type 2 diabetes mellitus and acute myelocytic leukemia M2a. With the antifungal therapy, her symptoms, signs and general conditions improved. Regrettably, she gave up the treatment, and died three months later for unknown reason. Patient two was a 60-year-old woman, with the complaints of chronic sinusitis, swelling and necrotic lesion in the right temporal area. Although the mycelium was recovered in biopsy tissues from the necrotic lesion, the diagnosis was revised to extranodal NK/TCL by reviewing the histopathological features and immunophenotypic analysis. The patient also voluntarily abandoned treatment, and died at home for unknown reason. The differential diagnosis of facial mucormycosis and extranodal NK/TCL is usually perplexing.

Changing Epidemiology of Mucoralean Fungi: Chronic Cutaneous Infection Caused by Mucor irregularis

INTRODUCTION

The fungi pertaining to order Mucorales usually cause an acute form of clinical disease called mucormycosis. A primary chronic presentation in an immunocompetent patient is a rare form of mucormycosis. Mucor irregularis is known for causing chronic cutaneous infections geographically confined to Asia, mainly in China. We describe a case of primary chronic cutaneous mucormycosis caused by M. irregularis from a new geographical niche in India, highlighting changing aspects of its epidemiology.

CASE PRESENTATION

The patient was a farmer with a history of skin lesions over the lower limb for the past 6 years. The biopsy taken from the lesions showed pauci-septate hyphae with right-angle branching on KOH wet mount as well as special fungal stains. On fungal culture, greyish-white cottony mycelial growth of Mucormycetes was obtained. The strain was finally identified as M. irregularis on macro- and microscopic features on 2 % MEA and DNA sequencing. The antifungal susceptibility was done using EUCAST broth microdilution method and was found to be susceptible to commonly used antifungal agents. The patient was started on oral itraconazole and saturated solution of potassium iodide (SSKI). While undergoing treatment for 2 months, he was lost to follow-up, however, after a year when he recently visited the hospital; the disease got completely healed with no new crops of skin lesions.

CONCLUSION

Mucoralean fungi should also be suspected in cases with chronic presentation, in immunocompetent host, as there is emergence of such fungi in new endemic areas, particularly located in Asia. The role of other antifungal agents apart from amphotericin B for the treatment of chronic mucormycosis needs to be explored.

Primary cutaneous mucormycosis caused by Mucor irregularis

We describe a case of primary cutaneous mucormycosis in a 44-year-old man with an 18-month history of infiltrative erythematous plaques and haemorrhagic crusting on the dorsum of his left hand. The isolate was identified as Mucor irregularis (formerly Rhizomucor variabilis) based on the fungus morphology and DNA sequencing results. Improvement was observed after a 6-month treatment course of itraconazole. No recrudescence was seen during a follow-up of 23 months after treatment.

Primary cutaneous mucormycosis caused by Mucor irregularis in an elderly person

Primary cutaneous mucormycosis is a rare but often lethal severe fungal infection, which usually occurs in immunocompromised patients. We report a case of primary cutaneous mucormycosis caused by Mucor irregularis in an elderly patient. Seven months after the surgical dissection of the involved skin, cutaneous mucormycosis recurred at the peripheral edge of the skin graft. Shortly subsequent to the administration of liposomal amphotericin B, the remaining skin lesion was excised again. M. irregularis is rarely but increasingly reported as a cause of mucormycosis in immunocompetent individuals, especially in Asian farmers. M. irregularis may be largely disseminated in the soils of Asia and thus the trivial trauma at the time of farm work may be a trigger for the onset. These cases tend to leave severe cosmetic damage even in healthy individuals, although the vital prognosis is not affected.

Mucor irregularis-associated cutaneous mucormycosis: Case report and review

Solid organ transplant recipients are at risk for invasive fungal diseases, and are also exposed to healthcare-associated mucormycosis. Mainly causing localized cutaneous mucormycosis, Mucor irregularis infection is reported for the first time in a kidney-transplant recipient. A healthcare-associated origin was highly suspected in this case. We performed a literature review and highlight the characteristics of this very rare fungus.

Mucor irregularis infection around the inner canthus cured by amphotericin B: a case report and review of published literatures

We report a case of primary cutaneous mucormycosis caused by Mucor irregularis. A 47-year-old farmer was presented to our clinic with the history of progressive red plaque around the inner canthus following dacryocystectomy about a year earlier. Linear, aseptate hyphae were seen by direct KOH examination and in biopsy. Fungal culture revealed light yellow filamentous colonies that were identified as Mucor irregularis by nucleotide sequencing of rRNA gene. Amphotericin B and dexamethasone were used in gradually increasing dosage. The treatment lasted 43 days, and the patient received 760 mg total amphotericin B. The patient was discharged after 2 months of treatment. The plaque became smooth, and fungal culture was negative. There was no recurrence for half a year through telephone follow-ups. A review of published studies revealed 23 cases of Mucor irregularis infection. Most cases resulted following injuries or surgical complications. Farmers and manual laborers were most at risk with males outnumbering females among patients. Amphotericin B and its liposomal preparations remain most effective treatment choices.

Successful treatment of a necrotizing fasciitis patient caused by Mucor indicus with amphotericin B and skin grafting

Cutaneous mucormycosis, an uncommon disease caused by Mucorales, predominantly occurs in immunocompromised host. The present case is a primary cutaneous mucormycosis due to Mucor indicus in an immunocompetent individual. It is with the features of necrotizing fasciitis over the right pretibial area. We are presenting this case owing to its rarity and the successful treatment with amphotericin B and skin grafting.

Rhizomucor variabilis: a rare causative agent of primary cutaneous zygomycosis

Rhizomucor variabilis is a rare cause of human infections. We report a case of primary cutaneous zygomycosis in an immunocompetent host. Although microscopy reveals the fungal aetiology, the need for species identification is highlighted to better understand the species and establish an epidemiological pattern as it is reported from restricted geographical locations.

Drug combinations against Mucor irregularis in vitro

Combinations of terbinafine or caspofungin with amphotericin B, posaconazole, or itraconazole were studied as potential treatments against 18 isolates of Mucor irregularis in vitro. Synergism of the combinations of terbinafine with amphotericin B, posaconazole, and itraconazole against 38.9, 33.3, and 44.4% of the strains studied was observed. In contrast, synergism of the combinations of caspofungin with amphotericin B, posaconazole, and itraconazole against 99.4, 66.7, and 99.4% of the strains studied was observed. Furthermore, no antagonism was observed.

Global epidemiology of cutaneous zygomycosis

The large majority of cases reported worldwide as zygomycosis are infections caused by fungi belonging to the order Mucorales. These infections are invasive, often lethal, and they primarily affect immunocompromised patients. Cutaneous zygomycosis is the third most common clinical presentation, after sinusitis and pulmonary disease. Most patients with cutaneous zygomycosis have underlying diseases, such as hematological malignancies and diabetes mellitus, or have received solid organ transplantation, but a large proportion of these patients are immunocompetent. Trauma is an important mode of acquiring the disease. The disease can be very invasive locally and penetrate from the cutaneous and subcutaneous tissues into the adjacent fat, muscle, fascia, and bone. The diagnosis of cutaneous zygomycosis is often difficult because of the nonspecific findings of the infection. The clinician must have a high degree of suspicion and use all available diagnostic tools, because early diagnosis leads to an improved outcome. The treatment of zygomycosis is multimodal and consists of surgical debridement, use of antifungal drugs, and reversal of underlying risk factors, when possible. The main antifungal drug used in the treatment of zygomycosis is amphotericin B. Posaconazole is sometimes used for salvage treatment, as continuation of treatment after initial administration of amphotericin B, or in combination. The mortality of cutaneous zygomycosis is lower in comparison with other forms of the disease, but it is still significant. When the disease is localized, mortality still ranges from 4% to 10%.

Taxonomy and epidemiology of Mucor irregularis, agent of chronic cutaneous mucormycosis

Mucormycosis usually presents as a progressive infection with significant angio-invasion. Mucormycosis due to Mucor irregularis (formerly Rhizomucor variabilis var. variabilis), however, is exceptional in causing chronic cutaneous infection in immunocompetent humans, ultimately leading to severe morbidity if left untreated. More than 90 % of the cases known to date were reported from Asia, mainly from China. The nearest neighbour of M. irregularis is the saprobic species M. hiemalis. The aim of this study was to evaluate the taxonomic position, epidemiology, and intra- and inter-species diversity of M. irregularis based on 21 strains (clinical n = 17) by multilocus analysis using ITS, LSU, RPB1 and RPB2 genes, compared to results of cluster analysis with amplified fragment length polymorphism (AFLP) data. By combining MLST and AFLP analyses, M. irregularis was found to be monophyletic with high bootstrap support, and consisted of five subgroups, which were not concordant in all partitions. It was thus confirmed that M. irregularis is a single species at 96.1–100 % ITS similarity and low recombination rates between populations. Some geographic structuring was noted with some localised populations, which may be explained by limited air-dispersal. The natural habitat of the species is likely to be in soil and decomposing plant material.

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).

Diagnosis of pulmonary mucormycosis aiding the diagnosis of small cell lung cancer

Mucormycosis is a rare complication in immunocompromised patients. Antemortem diagnosis of mucormycosis is difficult and often incorrect. We report a case of pulmonary mucormycosis caused by Cunninghamella bertholletiae in an elderly man with interstitial pneumonia. The diagnosis of mucormycosis was established by bronchoalveolar lavage. A coexisting immune deficiency condition was considered. Lung cancer was suspected because of an elevated progastrin-releasing peptide level and bilateral hilar and mediastinal lymphadenopathy; it was diagnosed after performing endoscopic ultrasound-guided fine-needle aspiration. Treatment by intravenous liposomal amphotericin B was effective, but relapse occurred because of bone marrow suppression caused by chemotherapy for lung cancer. Treatment for mucormycosis was resumed, but the patient died of carcinomatous lymphangiosis. Autopsy confirmed the diagnosis of pulmonary mucormycosis and revealed refractory anaemia with small cell lung cancer. Mucormycosis often occurs in immunocompromised patients, but this case is rare because the mucormycosis was diagnosed before the diagnosis of malignancy. Because prognosis is often poor, the possibility of coexisting malignancies should always be investigated in patients with mucormycosis infections.

Mucor irregularis infection and lethal midline granuloma: a case report and review of published literature

Mucor irregularis (Rhizomucor variabilis) infection and lethal midline granuloma (LMG) are characterized by progressive swelling, ulceration, and destruction of the central face that is usually fatal. Pathological features are inflammation, necrosis, and granulation. LMG has been called by various names, and in recent years, it has been known as NK/T cell lymphoma. However, diagnosis still relies on the progressive necrosis course rather than malignancy in histology. The disease has long challenged physicians, particularly when it worsens with radiotherapy or chemotherapy but sometimes achieves total remission without anti-malignancy therapies. We describe a 35-year-old man who had typical clinical-pathological symptoms of LMG, which turned out to be primary M. irregularis infection; that was diagnosed by positive tissue culture and fungal elements in histology. The patient was successfully treated with antifungal therapy (liposomal amphotericin B, total 4,600 mg and amphotericin B total 277 mg, over a duration of 70 days). We hereby review current knowledge about the epidemiology, clinical manifestations, radiographic characteristics, and pathologic features of LMG with those of M. irregularis infection and their associations. We conclude that primary M. irregulars infection can mimic the clinico-pathological symptoms of LMG and the condition responds favorably to aggressive antifungal therapy.

The emerging epidemiology of mould infections in developing countries

PURPOSE OF REVIEW

The present review describes the emerging trends of mould infections in developing countries, and highlights the major epidemiological differences from the developed countries.

RECENT FINDINGS

The limited data available from developing countries suggest an alarming increase in invasive mould infections, especially aspergillosis and mucormycosis, and also a difference in risk factors and causative agents between the developed and developing world. Sino-orbital, cerebral and ophthalmic infections due to Aspergillus flavus are the major clinical types in aspergillosis, after pulmonary aspergillosis. Aspergillus and Fusarium spp. are frequent causes of trauma-associated keratitis in agricultural workers. Rhino-orbito-cerebral presentation associated with uncontrolled diabetes is the predominant mucormycosis. Isolated renal mucormycosis has emerged as a new clinical entity. Apophysomyces elegans and Mucor irregularis are emerging species in these regions and uncommon agents such as Rhizopus homothallicus have also been reported. Many pathogens are geographically restricted, with Pythium insidionum, Rhinocladiella mackenziei and M. irregularis being described almost exclusively from Thailand, Middle East and China, respectively.

SUMMARY

Despite limited studies, certain peculiarities have been observed in invasive mould infections in developing countries, including a high incidence of ophthalmic lesions, mucormycosis and aspergillosis; few different clinical presentations; and a varied spectrum of pathogens involved in such lesions.

Mucormycosis caused by unusual mucormycetes, non-Rhizopus, -Mucor, and -Lichtheimia species

Rhizopus, Mucor, and Lichtheimia (formerly Absidia) species are the most common members of the order Mucorales that cause mucormycosis, accounting for 70 to 80% of all cases. In contrast, Cunninghamella, Apophysomyces, Saksenaea, Rhizomucor, Cokeromyces, Actinomucor, and Syncephalastrum species individually are responsible for fewer than 1 to 5% of reported cases of mucormycosis. In this review, we provide an overview of the epidemiology, clinical manifestations, diagnosis of, treatment of, and prognosis for unusual Mucormycetes infections (non-Rhizopus, -Mucor, and -Lichtheimia species). The infections caused by these less frequent members of the order Mucorales frequently differ in their epidemiology, geographic distribution, and disease manifestations. Cunninghamella bertholletiae and Rhizomucor pusillus affect primarily immunocompromised hosts, mostly resulting from spore inhalation, causing pulmonary and disseminated infections with high mortality rates. R. pusillus infections are nosocomial or health care related in a large proportion of cases. While Apophysomyces elegans and Saksenaea vasiformis are occasionally responsible for infections in immunocompromised individuals, most cases are encountered in immunocompetent individuals as a result of trauma, leading to soft tissue infections with relatively low mortality rates. Increased knowledge of the epidemiology and clinical presentations of these unusual Mucormycetes infections may improve early diagnosis and treatment.

Chronic rhinofacial mucormycosis caused by Mucor irregularis (Rhizomucor variabilis) in India

In this article, we describe a chronic case of rhinofacial mucormycosis caused by Mucor irregularis, formerly known as Rhizomucor variabilis var. variabilis, a rare mycotic agent in humans. The infection caused progressive destruction of the nasal septum and soft and hard palate, leading to collapse of the nose bridge and an ulcerative gaping hole. The mucoralean mold cultured from a nasal biopsy specimen was determined by multilocus DNA sequence data to be conspecific with M. irregularis.

Heterothallic mating in Mucor irregularis and first isolate of the species outside of Asia

This study reports on the discovery of heterothallic mating in Mucor irregularis (formerly Rhizomucor variabilis var. variabilis) and it extends the range of this species from Asia to the United States. We report on a case of primary cutaneous mucormycosis, involving the forearms of a cotton farmer from North Carolina, in which the infection was cured using amphotericin B therapy. Intraspecific crosses between the North Carolina strain DUMC 150.04 and M. irregularis CBS 103.93, the ex-type strain of R. variabilis var. variabilis from China, resulted in the formation of abundant fertile zygospores. By way of contrast, interspecific crosses between the North Carolina isolate and the ex-neotype strain of M. hiemalis NRRL 3624 resulted in the formation of putative azygospores by M. irregularis DUMC 150.04.

Identification and susceptibility of Rhizomucor spp. isolated from patients with cutaneous zygomycosis in China

Zygomycosis is a relatively uncommon mycosis with a morbidity that is increasing worldwide. Cutaneous zygomycosis, one of the clinical manifestations of the disease, has also emerged in recent decades. The major reported etiologic agents in China include Rhizomucor spp., Rhizopus spp., Mucor spp., and Lichtheimia spp. (formerly Absidia spp.). This study examined 11 clinical isolates of Rhizomucor that belong to three species (R. variabilis, R. regularior, and R. chlamydosporus). They were identified by both morphological and molecular methods and were found to have a high degree of correlation. In vitro susceptibility of the Rhizomucor isolates to seven antifungal drugs (amphotericin B, itraconazole, terbinafine, voriconazole, fluconazole, flucytosine, and micafungin) were tested, which resulted in amphotericin B being found to be the most active agent against all species evaluated in this study. The investigation also reviewed case reports of cutaneous zygomycosis in China.

Zygomycosis in Immunocompromised non-Haematological Patients

Zygomycoses caused by fungi of the mucorales order (mucormycoses) are emerging fungal diseases with a high fatality rate. The most important risk factors include neutropenia or functional neutropenia, diabetic ketoacidosis, iron overload, major trauma, prolonged use of corticosteroids, illicit intravenous drug (ID) use, neonatal prematurity, malnourishment, and maybe a previous exposure to antifungal agents with no activity against zygomycetes, such as voriconazole and echinocandins.A high index of suspicion is crucial for the diagnosis, as prompt and appropriate management can considerably reduce morbidity and mortality. Suspicion index can be increased through recognition of the differential patterns of clinical presentation. In the non- haematological immunocompromised patients, mucormycosis can manifest in various clinical forms, depending on the underlying condition: mostly as rhino-orbital or rhino-cerebral in diabetes patients, pulmonary infection in patients with malignancy or solid organ transplantation, disseminated infection in iron overloaded or deferoxamine treated patients, cerebral - with no sinus involvement - in ID users, gastrointestinal in premature infants or malnourishment, and cutaneous after direct inoculation in immunocompetent individuals with trauma or burns.Treating a patient's underlying medical condition and reducing immunosuppression are essential to therapy. Rapid correction of metabolic abnormalities is mandatory in cases such as uncontrolled diabetes, and corticosteroids or other immunosuppressive drugs should be discontinued where feasible. AmphotericinB or its newer and less toxic lipid formulations are the drugs of choice regarding antifungal chemotherapy, while extensive surgical debridement is essential to reduce infected and necrotic tissue. A high number of cases could be prevented through measures including diabetes control programmes and proper pre- and post-surgical hygiene.

Rhizomucor variabilis var. regularior and Hormographiella aspergillata infections in a leukemic bone marrow transplant recipient with refractory neutropenia

Rhizomucor variabilis and Hormographiella aspergillata rarely cause human infections. This report details a fatal case of a 14-year-old female with leukemia posthematopoietic cell transplant and relapse with refractory pancytopenia. The patient first developed an R. variabilis var. regularior palate infection and later developed a cutaneous H. aspergillata infection while on posaconazole and caspofungin therapy.