Apophysomyces variabilis infections in humans

Phytochemical Investigation and in vitro Antimicrobial and Antioxidant Activities Evaluation of Erianthemum aethiopicum Wiens and Polhill

Background

Erianthemum aethiopicum Wiens and Polhill (Loranthaceae) is a parasitic plant native to north eastern Africa and Ethiopia. In Ethiopia, it is traditionally used to treat breast swelling, mastitis, morning illnesses and vomiting.

Objective

This study aimed to screen the main phytochemical constituents; determine the total amounts of phenolics, flavonoids, and tannins; and evaluate the antimicrobial (against Escherichia coli, Staphylococcus sciuri, Candida glaebosa and Cryptococcus albidus) and antioxidant (against DPPH radical and ferric ion) activities of E. aethiopicum leaves extracts.

Methods

Powdered E. aethiopicum leaves were macerated using n-hexane, chloroform, ethyl acetate, ethanol, and methanol. All crude extracts were qualitatively screened for phytochemical identification. The total phenolic, flavonoid, and condensed tannin contents of the chloroform, ethanol, and methanol extracts were determined by UV-Vis spectrophotometry. The n-hexane, chloroform, and methanol extracts were evaluated for their antimicrobial activity against the aforementioned microbes using agar disc diffusion and broth micro-dilution techniques. Chloroform, ethanol, and methanol extracts were also evaluated for antioxidant activity by DPPH and ferric ion reduction antioxidant power (FRAP) assays.

Results

Methanol (17.56 ± 16%) and ethanol (16.45 ± 19%) showed better extraction efficiency. Flavonoids, polyphenols, tannins, terpenoids, saponins, and sterols were detected in all extracts. The highest total content of phenolics (22.63 ± 0.69 mgGAE/gDCE), flavonoids (5.38 ± 0.52 mgCE/gDCE) and tannins (39.18 ± 38 mg CE/g DCE), as milligram of gallic acid and catechin per gram of dried crude extract, were recorded in the methanolic extract. The methanolic extract also presented best anti -DPPH strength (IC50, 4.31 μg/mL) and ferric ion reduction power (absorbance of 0.71) though found weak compared to the ascorbic acid (IC50 of 0.49 μg/mL and absorbance of 0.93, respectively).

Conclusion

All evaluated extracts displayed antifungal activity against both Cryptococcus albidus and Candida glaebosa strains (minimum inhibitory concentration values of 12.5-25 mg/mL), whereas they were found to have negligible activity against all tested bacterial strains. This report provides preliminary information for further phytochemical investigation of Erianthemum aethiopicum to isolate potential antioxidant and antifungal compounds.

Diverse Clinical Manifestations and Challenges of Mucormycosis: Insights From Serial Cases

Mucormycosis is a severe and potentially life-threatening infection caused by a group of fungi classified as mucormycetes within the scientific order Mucorales. These infections are characterized by rapid and invasive fungal growth, presenting significant treatment challenges. Here we present 5 cases encountered from 2018 to 2022 at the University of Texas Medical Branch in Galveston, Texas, including a novel Apophysomyces species. These cases illustrate the diverse clinical manifestations of mucormycosis, including pulmonary, rhino-cerebral, gastrointestinal, and soft tissue involvement. Our investigation incorporates information provided by a multidisciplinary team of clinical collaborators, emphasizing the findings from radiology, histopathology, and microbiology. Given the escalating global incidence of mucormycosis, it is crucial for clinicians to become familiar with associated clinical findings, comorbidities, and risk factors to facilitate prompt recognition, appropriate diagnostic testing, and timely initiation of treatment.

Part 1: Mucormycosis: Prevalence, Risk Factors, Clinical Features and Diagnosis

INTRODUCTION

Mucormycosis (MCR) is caused by filamentous molds within the Class Zygomycetes and Order Mucorales. Infections can result from inhalation of spores into the nares, oropharynx or lungs, ingestion of contaminated food or water, or inoculation into disrupted skin or wounds. In developed countries, MCR occurs primarily in severely immunocompromised hosts. In contrast, in developing/low income countries, most cases of MCR occur in persons with poorly controlled diabetes mellitus and some cases in immunocompetent subjects following trauma. Mucormycosis exhibits a propensity to invade blood vessels, leading to thrombosis and infarction of tissue. Mortality rates associated with invasive MCR are high and can exceed 90% with disseminated disease. Mucormycosis can be classified as one of six forms: (1) rhino-orbital-cerebral mucormycosis (ROCM); (2) pulmonary; (3) cutaneous; (4) gastrointestinal or renal (5); disseminated; (6) uncommon (focal) sites.

AREAS COVERED

The authors discuss the prevalence, risk factors and clinical features of mucormycosis.A literature search of mucormycosis was performed via PubMed (up to November 2022), using the key words: invasive fungal infections; mold; mucormycosis; Mucorales; Zyzomyces; Zygomycosis; Rhizopus, diagnosis.

EXPERT OPINION

Mucormycosis occurs primarily in severely immunocompromised hosts. Mucormycosis can progress rapidly, and delay in initiating treatment by even a few days worsens outcomes.

Mucormycosis caused by Apophysomyces species: An experience from a tertiary care hospital in Western India and systematic review of global cases

Apophysomyces species are an emerging cause of mucormycosis in several regions of the world, primarily affecting immunocompetent individuals. The present study addresses the global epidemiology, clinical presentation, management and outcome of mucormycosis caused by Apophysomyces spp. The study included patients diagnosed with Apophysomyces infection at our hospital between March 2019 and August 2020. In addition, cases published in PubMed and Google Scholar from inception to July 2022 were systematically searched and analysed. Only proven and probable cases that meet the eligibility criteria were included. The Indian cases were compared with those from other countries, and the results were analysed by descriptive statistics. In total, six cases of mucormycosis due to Apophysomyces spp. were diagnosed at our hospital, with additional 250 cases identified through literature search. The main underlying diseases were diabetes mellitus (24%), malignancy (3.2%) and chronic kidney disease (2.8%). The major predisposing factor was trauma (55.6%). Necrotizing fasciitis was the most common (63.2%) clinical presentation. Healthcare-associated mucormycosis accounted for 10.4% of the cases. Globally, A. elegans was the most common species (48.8%), whereas A. variabilis was predominant (86.2%) in India. Surgery was performed in 83.5% of patients. Among those treated with antifungal agents, 98% received amphotericin B and 8.1% received posaconazole. Inappropriate antifungal usage was observed in 12.7%. The overall mortality was 42.3%. A combined medical and surgical management was associated with higher survival. Our study highlights the knowledge gap among physicians regarding this infection. A timely diagnosis and aggressive management can improve the outcomes in such cases.

Unmet needs and practical solutions in the management of invasive mould infections in Asia

Management of invasive mould infections (IMIs) is challenging in Asia, as awareness among medical practitioners can be low and resources are limited. Timely diagnosis and appropriate treatment of IMIs can mitigate the impact on morbidity and mortality, but diagnostic methods, as well as access to preferred antifungal medications, may vary throughout the region. Knowledge of local epidemiology and accurate diagnosis and identification of causal pathogens would facilitate optimal treatment but data in Asia are lacking. To address these unmet needs in the management of IMIs, this paper is a call for urgent action in the following areas: improving awareness of the threat of IMIs; providing education to frontline clinicians across a broad range of specialties on 'red flags' for suspicion of IMIs; prioritizing cost-effective rapid diagnostic testing; improving access to preferred antifungal medications; and closing the gaps in local epidemiological data on IMIs to inform local treatment guidelines.

Apophysomyces variabilis, an emerging and worrisome cause of primary cutaneous necrotizing infections in India

In India, Apophysomyces species complex is the second common agent of mucormycosis mainly affecting immunocompetent hosts unlike other Mucorales. It is frequently involved in causing necrotizing cutaneous infections. The present two-year study was planned to investigate the causative role of Apophysomyces spp. in cutaneous necrotizing infections. The tissue samples were processed using standard techniques and in five out of 65 patients, Apophysomyces variabilis was the etiological agent. Diabetes mellitus and trauma were common risk factors and despite appropriate treatment only one patient could be survived. Apophysomyces variabilis is emerging as agent of necrotizing infections which invariably result in poor patient outcomes.

Rhino-orbital mucormycosis due to Apophysomyces ossiformis in a patient with diabetes mellitus: a case report

Background

The most common aetiological agents of mucormycosis are Rhizopus, Mucor, Apophysomyces and Lichtheimia. Apophysomyces is comparatively rare, as it has been reported in less than 3% of mucormycosis cases. The genus Apophysomyces includes six species, and only A. elegans, A. mexicanus, A. variabilis and A. ossiformis have been reported to cause infections in both immunocompetent and immunocompromised patients.

Case presentation

We present a case of a 46-year-old male patient with bilateral blepharoedema, corneal opacity in the left eye and poorly controlled diabetes mellitus. The patient was subjected to total maxillectomy, exenteration of the left orbit and treatment with liposomal amphotericin B. Direct mycological analysis with KOH 10% revealed hyaline, coenocytic, long and wide hyphae. Apophysomyces ossiformis was identified from maxillary biopsy using 18S-ITS1–5.8S-ITS2-28S rRNA gene amplification and sequencing. The patient requested to be transferred to another hospital to continue treatment, where he died on the ninth day after admittance.

Conclusion

To the best of our knowledge, this is the first case of rhino-orbital mucormycosis due to A. ossiformis with a fatal outcome. This case reveals the need to identify the fungus causing mucormycosis with molecular methods to identify adequate treatment therapies for patients with this infection.

Mucormycosis due to Apophysomyces species complex- 25 years' experience at a tertiary care hospital in southern India

Apophysomyces elegans species complex is an important cause of cutaneous mucormycosis in India. However, majority of those cases are reported as case reports only. We desired to analyze our patients with Apophysomyces infection reported over 25 years (1992-2017) to understand the epidemiology, management, and outcome of the disease. During the study period 24 cases were reported, and the majority (95.8%) of them presented with necrotizing fasciitis following accidental/surgical/iatrogenic trauma. One patient presented with continuous ambulatory peritoneal dialysis (CAPD) related peritonitis. Healthcare related Apophysomyces infection was noted in 29.2% patients. In addition to trauma, comorbidities were noted in 37.5% patients (type 2diabetes mellitus-6, chronic alcoholism-2, and chronic kidney disease-1). Of the 24 isolates, 11 isolates starting from year 2014 were identified as Apophysomyces variabilis by molecular methods. Majority (95.8%) of the patients were managed surgically with or without amphotericin B deoxycholate therapy, while one patient was treated with amphotericin B deoxycholate alone. Among 24 patients, seven (29.1%) recovered, six (25%) patients could not afford antifungal management and left the hospital against medical advice, and 11 (45.9%) patients died.The present case series highlights that necrotizing fasciitis caused by A. variabilis is prevalent in India, and the disease may be healthcare related. Although diagnosis is not difficult, awareness among surgeons is still limited about the infection, leading to a delay in sending samples to the mycology laboratory. Apophysomyces infection must be considered in the differential diagnosis in apatient with progressive necrosis of a wound who is not responding to antibacterial therapy.

Necrotizing fasciitis caused by Apophysomyces variabilis in a burn patient

The genus Apophysomyces belonging to the order Mucorales is increasingly being reported as a cause of mucormycosis in immunocompetent patients. We report a case of necrotizing fasciitis caused by Apophysomyces variabilis in a 52-year-old immunocompetent male who sustained thermal burn in his right leg following a road-traffic accident. There was rapidly progressive necrosis of skin, soft tissues and underlying muscles which required extensive surgical debridement. Microscopic examination of excised tissues revealed broad aseptate fungal hyphae. Fungal culture on Sabouraud dextrose agar (SDA) showed growth of a mucoraceous mould which was identified as A. variabilis based on characteristic microscopic morphology and internal transcribed spacer sequencing of the ribosomal DNA. The isolate was found to sporulate on SDA, a finding that was unique as Apophysomyces spp. does not usually sporulate on primary isolation medium used in mycology laboratories. The disease progressed as there was an initial assumption of bacterial infection and the fungus was isolated late in the course of the disease because of which no antifungal drug was added to the regime. The patient left against medical advice and eventually underwent below-knee amputation at another city hospital a week later. Infection due to A. variabilis should be considered as a differential diagnosis of rapidly progressive necrosis of skin and soft tissues in immunocompetent individuals as early diagnosis and management will prevent the disease progression and a possible amputation.

An aero mycological analysis of Mucormycetes in indoor and outdoor environments of northern India

Mucormycosis is an angio-invasive infection, predominantly acquired by inhalation of sporangiospores from the environment. However, the burden of Mucormycetes sporangiospores in the air is not well studied. We aimed to estimate the burden of Mucormycetes spores in the outdoor and indoor (hospital) environment across different seasons in north India. A total of 380 air samples from outdoor (n = 180) and indoor (n = 200) environment were included in the study. Air samples were suctioned using air sampler (100 l/min) and cultured on Dichloran Rose Bengal Chloramphenicol (DRBC) with benomyl for selective isolation of Mucormycetes. The isolates were identified by phenotypic and genotypic methods. The mean spore count (±SD) of Mucormycetes (cfu/m3) in outdoor samples varied from 0.73 (±0.96) to 8.60 (±5.70) across different seasons. In hospital, the mean spore count varied from 0.68 (±1.07) to 1.12 (±1.07) and 0.88 (±1.01) to 1.72 (±2.17) for air-conditioned wards and non-air-conditioned wards, respectively. Rhizopus arrhizus was the predominant agent isolated from both indoor and outdoor environment followed by Cunninghamella species. We also report a single isolate of the rare mucormycete agent, Apophysomyces variabilis from outdoor environment. The present study highlights the presence of low spore burden of Mucormycetes in outdoor and hospital settings in north India. This study also reports the first isolation of A. variabilis from air samples in the Indian subcontinent.

Apophysomycesthailandensis (Mucorales, Mucoromycota), a new species isolated from soil in northern Thailand and its solubilization of non-soluble minerals

A new species of soil fungi, described herein as Apophysomycesthailandensis, was isolated from soil in Chiang Mai Province, Thailand. Morphologically, this species was distinguished from previously described Apophysomyces species by its narrower trapezoidal sporangiospores. A physiological determination showed that A.thailandensis differs from other Apophysomyces species by its assimilation of D-turanose, D-tagatose, D-fucose, L-fucose, and nitrite. A phylogenetic analysis, performed using combined internal transcribed spacers (ITS), the large subunit (LSU) of ribosomal DNA (rDNA) regions, and a part of the histone 3 (H3) gene, lends support to our the finding that A.thailandensis is distinct from other Apophysomyces species. The genetic distance analysis of the ITS sequence supports A.thailandensis as a new fungal species. A full description, illustrations, phylogenetic tree, and taxonomic key to the new species are provided. Its metal minerals solubilization ability is reported.

Necrotizing fasciitis caused by Apophysomyces variabilis in an immunocompetent patient

Mucormycosis caused by Apophysomyces variabilis is rarely reported in humans. A case of A. variabilis infection in an immunocompetent men after friction burns in a car accident is described. The infection presented as a rapidly progressive necrotizing infection of the skin and soft tissue, which required extensive surgical debridement and total colonic defunctioning colostomy associated with prolonged antifungal therapy. A. variabilis infection should be considered as a differential diagnosis of rapidly progressive necrotizing skin and soft tissue infections in immunocompetent individuals.

Apophysomyces variabilis: draft genome sequence and comparison of predictive virulence determinants with other medically important Mucorales

Background

Apophysomyces species are prevalent in tropical countries and A. variabilis is the second most frequent agent causing mucormycosis in India. Among Apophysomyces species, A. elegans, A. trapeziformis and A. variabilis are commonly incriminated in human infections. The genome sequences of A. elegans and A. trapeziformis are available in public database, but not A. variabilis. We, therefore, performed the whole genome sequence of A. variabilis to explore its genomic structure and possible genes determining the virulence of the organism.

Results

The whole genome of A. variabilis NCCPF 102052 was sequenced and the genomic structure of A. variabilis was compared with already available genome structures of A. elegans, A. trapeziformis and other medically important Mucorales. The total size of genome assembly of A. variabilis was 39.38 Mb with 12,764 protein-coding genes. The transposable elements (TEs) were low in Apophysomyces genome and the retrotransposon Ty3-gypsy was the common TE. Phylogenetically, Apophysomyces species were grouped closely with Phycomyces blakesleeanus. OrthoMCL analysis revealed 3025 orthologues proteins, which were common in those three pathogenic Apophysomyces species. Expansion of multiple gene families/duplication was observed in Apophysomyces genomes. Approximately 6% of Apophysomyces genes were predicted to be associated with virulence on PHIbase analysis. The virulence determinants included the protein families of CotH proteins (invasins), proteases, iron utilisation pathways, siderophores and signal transduction pathways. Serine proteases were the major group of proteases found in all Apophysomyces genomes. The carbohydrate active enzymes (CAZymes) constitute the majority of the secretory proteins.

Conclusion

The present study is the maiden attempt to sequence and analyze the genomic structure of A. variabilis. Together with available genome sequence of A. elegans and A. trapeziformis, the study helped to indicate the possible virulence determinants of pathogenic Apophysomyces species. The presence of unique CAZymes in cell wall might be exploited in future for antifungal drug development.

Electronic supplementary material

The online version of this article (10.1186/s12864-017-4136-1) contains supplementary material, which is available to authorized users.

Serious fungal infections in Chile

The incidence and prevalence of fungal infections in Chile are unknown. Here, we have estimated the burden of serious fungal diseases from data obtained from clinical reports, WHO reports, Chilean census, OECD reports and comprehensive literature search available on PubMed and SciELO, among other scientific resources. Due the lack of official data about fungal diseases, frequencies were calculated based on the specific populations at risk. Recurrent vulvovaginal candidiasis (>4 episodes/year) is estimated to occur in 3108/100,000. Using a low international average rate of 5/100,000, we estimate 878 candidaemia cases and 132 patients with intra-abdominal candidiasis. Due to the low incidence of pulmonary tuberculosis (TB) in Chile, limited numbers of patients with chronic pulmonary aspergillosis are likely: a total of 1212, 25% following TB. Invasive aspergillosis is estimated to affect 296 patients following leukaemia therapy, transplantation and chronic obstructive pulmonary disease (COPD), 1.7/100,000. In addition, allergic bronchopulmonary aspergillosis (ABPA) and severe asthma with fungal sensitisation (SAFS) were estimated to be around 97.9/100,000 and 127/100,000 respectively, in 675,772 adult asthmatics and 1700 CF patients. Given a 38,000 human immunodeficiency virus (HIV) population, with around 2189 new cases of acquired immune deficiency syndrome (AIDS) annually, cryptococcal meningitis and Pneumocystis pneumonia are estimated at 0.12/100,000 and 4.3/100,000, respectively. In total, 325,000 (1.9%) people in Chile develop serious fungal infections annually. Respiratory fungal disease predominates in Chile; a national action plan for fungal disease is urgently needed, including epidemiological studies to validate the estimates.

Chronic orbital and calvarial fungal infection with Apophysomyces variabilis in an immunocompetent patient

Apophysomyces is a rare fungal organism causing rhino-orbito-cerebral mycotic infections with high morbidity and mortality, typically in immunocompetent individuals. Several cases of Apophysomyces elegans orbital disease have been reported. Herein, we report a case of Apophysomyces variabilis infection involving the orbit, sinuses, and calvarium in an immunocompetent 74-year-old woman, with a review of the literature. Unlike prior cases of A. elegans classic rhino-orbito-cerebral infection, our case included diffuse calvarial lytic lesions and overlying soft tissue nodules, but without parenchymal intracranial involvement. There was radiographic and clinical evidence of infarction of the orbital contents and cavernous sinus thrombosis. Anastomoses between the superior orbital (ophthalmic) vein and diploic veins of the calvarium are believed to be primarily responsible for the unusual mode of spread on the extradural surface of the brain. Although the patient stabilized without definitive surgical intervention, her disease slowly and intermittently progressed for over a year after presentation, requiring multiple courses of antifungal treatment.

The environmental source of emerging Apophysomyces variabilis infection in India

The rare mucoraceous fungus, Apophysomyces species complex ranks second after Rhizopus arrhizus causing mucormycosis in India. The source of this agent in the environment is not clearly known. We conducted an environmental study to find its presence in Indian soil. The soil samples from different geographical locations were analyzed for isolation of Mucorales. Rhizopus arrhizus (24.6%) was most commonly isolated from soil, followed by Lichtheimia spp. (23.2%), Cunninghamella spp. (21.7%), Rhizopus microsporus (14%) and Apophysomyces spp. (4.5%). The isolation of Apophysomyces species complex was significantly associated with low nitrogen content of the soil. Based on sequencing of internal transcribed spacer (ITS) and 28S (D1/D2) regions of ribosomal DNA, the Apophysomyces isolates were identified as Apophysomyces variabilis with 98 to 100% similarity to type strain A. variabilis (CBS658.93). The analysis of amplified fragment length polymorphism (AFLP) fingerprinting data demonstrated genomic diversity of A. variabilis isolates with multiple clades (similarity 40-90%). The minimum inhibitory concentrations (MIC), MIC50 and MIC90 for A. variabilis isolates were 1 and 4 μg/ml for amphotericin B, 0.25 and 0.5 μg/ml for itraconazole, 0.125 and 0.25 μg/ml for posaconazole, 0.06 and 0.12 μg/ml for terbinafine, respectively. The present study revealed abundant presence of A. variabilis in Indian soil with low nitrogen content, its genetic heterogeneity and relatively high MICs for amphotericin B.

Emerging infections caused by non-Aspergillus filamentous fungi

There are three broad groups of non-Aspergillus moulds: the mucormycetes, the hyalohyphomycetes and the phaeohyphomycetes. Infections with these pathogens are increasingly reported, particularly in the context of increasing use of immunosuppressant agents and improved diagnostics. The epidemiology of non-Aspergillus mould infections varies with geography, climate and level of immunosuppression. Skin and soft-tissue infections are the predominant presentation in the immunocompetent host and pulmonary and other invasive infections in the immunocompromised host. The more common non-Aspergillus moulds include Rhizopus, Mucor, Fusarium and Scedosporium species; however, other emerging pathogens are Rasamsonia and Verruconis species, which are discussed in this article. Outbreaks of non-Aspergillus mould infections have been increasingly reported, with contaminated medical supplies and natural disasters as common sources. Currently culture and other conventional diagnostic methods are the cornerstone of diagnosis. Molecular methods to directly detect and identify mould pathogens in tissue and body fluids are increasingly used.

Aggressive cutaneous zygomycosis caused by Apophysomyces variabilis in an immunocompetent child

A zygomycetous fungus was observed in a biopsy of a 9-year-old male. The patient was presented with severe cutaneous lesions subsequent to a traumatic car accident. Following fungal detection, antifungal treatment was prescribed but condition deteriorated rapidly and above knee amputation was done as lifesaving and to control fungal infection. Analysis of the 28 S rRNA gene (accession KT149770) aligned the isolate with members of the genus Apophysomyces and the pathogen was identified as Apophysomces variabilis.

A prospective study of mucormycosis in north India: experience from a tertiary care hospital

Mucormycosis is an emerging angioinvasive infection caused by the ubiquitous filamentous fungi of the Order Mucorales and class of Mucormycetes. We conducted a prospective study of 38 patients who were diagnosed as having mucormycosis in a tertiary care hospital during January 2010 to June 2011. The cases were analyzed regarding the site of involvement, underlying disease and species of fungi isolated, antifungal susceptibility pattern of the isolates, and outcome of therapy. The mean age of the patients was 40.43 years, with 72% male. Rhino-orbital mucormycosis (61.5%) was the most common presentation followed by cutaneous manifestations (31%), gastrointestinal symptoms (5%), and pulmonary (2.5%). Diabetes mellitus (56%) was the significant risk factor in rhino-orbito-cerebral presentation (OR = 7.55, P = 0.001). Among 23 culture isolates, Rhizopus arrhizus (37.5%) was the most common, followed by Apophysomyces variabilis (29.2%), Lichtheimia ramosa (16.7%), Rhizopus microsporus (4.2%), Rhizomucor pusillus (4.2%), and Apophysomyces elegans (4.2%). Rhizopus arrhizus was most commonly isolated from rhino-orbito-cerebral mucormycosis and Apophysomyces species were generally obtained from cutaneous mucormycosis. In vitro antifungal susceptibility showed that 16 isolates were sensitive to amphotericin B (MIC less than 1 μg/ml), while in contrast, all isolates were found to be resistant to voriconazole (MIC- 0.25 to >8), fluconazole (MIC > 32), flucytosine (MIC > 32). Treatment regimens included antifungal therapy, reversal of underlying predisposing risk factors, and surgical debridement. Combination of surgery and medical treatment with amphotericin B was significantly better (OR = 0.2, P < 0.04) than amphotericin B alone (61.5% vs. 10.3% patient survival). The awareness of fungal diseases amongst clinicians is required to decrease the fatal outcome of disease.

Posttraumatic mucormycosis: a nationwide study in France and review of the literature

Data on clinical, mycologic characteristics, and outcome of posttraumatic mucormycosis are scarce and often limited to case reports. From the French nationwide "RetroZygo" study, we compared posttraumatic mucormycosis cases with other forms of mucormycosis. We also reviewed reports of posttraumatic mucormycosis in the English-language literature from 1993 to 2013. We included all proven or probable cases for which underlying condition, route of infection, surgical and antifungal treatments, and outcome were detailed. From our cohort, posttraumatic mucormycosis (n = 16) differed significantly from other forms (n = 85) by rarity of underlying disease (31.2% vs 81%, p < 0.0001), frequency of cutaneous localization (87% vs 7%, p < 0.0001), short time before diagnosis (4.5 vs 21 d, p = 0.0002), species involved (Apophysomyces elegans complex and Saksenaea vasiformis), surgical requirement (93.7% vs 47%, p = 0.0006) and better survival (87.5% vs 47.6% at day 90, p = 0.03). We studied 122 cases of posttraumatic mucormycosis through our literature review. Most frequently reported traumas were traffic (37%), domestic accidents (15.1%), or natural disasters (13.4%). Mucormycosis occurred after extensive soft-tissue damage in 47.5% cases, with symptoms occurring a median of 9.5 days after trauma with necrosis being reported in 76.2% cases. Dissemination was found in 9% of patients, and bacterial coinfection in 41%. Nineteen percent of cases occurred in the Middle East or in India where Apophysomyces elegans complex was the predominant species recovered. Awareness of mucormycosis as a cause of posttrauma soft-tissue infection is warranted, especially in cases of soil-contaminated wounds. Survival is higher than in other forms of mucormycosis, but morbidity remains high.

Fungal necrotizing fasciitis, an emerging infectious disease caused by Apophysomyces (Mucorales)

BACKGROUND

The mucoralean fungi are emerging causative agents of primary cutaneous infections presenting in the form of necrotizing fasciitis.

AIMS

The aim of this study was to investigate a series of suspected necrotizing fasciitis cases by Apophysomyces species over one-year period in a northern Indian hospital.

METHODS

The clinical details of those patients suspected to suffer from fungal necrotizing fasciitis were recorded. Skin biopsies from local wounds were microscopically examined and fungal culturing was carried out on standard media. The histopathology was evaluated using conventional methods and special stains. Apophysomyces isolates were identified by their morphology and by molecular sequencing of the internal transcribed spacer (ITS) region of the ribosomal genes. Antifungal susceptibility testing was carried out following EUCAST guidelines and treatment progress was monitored.

RESULTS

Seven patients were found to be suffering from necrotizing fasciitis caused by Apophysomyces spp. Six isolates were identified as Apophysomyces variabilis and one as Apophysomyces elegans. Five patients had previously received intramuscular injections in the affected area. Three patients recovered, two died and the other two left treatment against medical advice and are presumed to have died due to their terminal illnesses. Posaconazole and terbinafine were found to be the most active compounds against A. variabilis, while the isolate of A. elegans was resistant to all antifungals tested.

CONCLUSIONS

Apophysomyces is confirmed as an aggressive fungus able to cause fatal infections. All clinicians, microbiologists and pathologists need to be aware of these emerging mycoses as well as of the risks involved in medical practices, which may provoke serious fungal infections such as those produced by Apophysomyces.

Primary cutaneous mucormycosis produced by the new species Apophysomyces mexicanus

A case of fungal necrotizing fasciitis that appeared in an immunocompetent Mexican woman after a car accident is described. The patient did not respond to antifungal treatment and died 4 days later. The fungus was molecularly identified as a new species of Apophysomyces, namely, Apophysomyces mexicanus.

Invasive Apophysomyces variabilis infection in a burn patient

Apophysomyces variabilis is an emerging fungal pathogen that can cause significant infections in immunocompetent patients. We report a case of A. variabilis invasive wound infection in a 21-year-old male after a self-inflicted burn injury.

Primary cutaneous zygomycosis in India

Cutaneous zygomycosis remains underdiagnosed despite being frequently encountered. Delay in the diagnosis contributes to delay in treatment, and a resultant high morbidity and mortality. A retrospective analysis of the reported cases of cutaneous zygomycosis from India was made using various search engines and cross-referencing from available manuscripts. A total of 42 publications from India on the topic were identified, since the first reported case of primary cutaneous zygomycosis by Veliath et al. (1976). There are 130 described cases of cutaneous zygomycosis with an overall mortality of 35 %. The commonest zygomycete identified was Apophysomyces elegans, and the commonest predisposing factor was breach of the skin. Surprisingly, diabetes was reported only in 36 cases (27.69 %). It is important to be aware of this unusual but fatal infection in order to manage it properly and have a good outcome.

[Taxonomy and biology of fungi causing human infection]

The advent of molecular techniques, mainly DNA sequencing, has led to important changes in the taxonomy of pathogenic fungi and a better understanding of the phylogenetic relationships among them. The number of fungal species potentially pathogenic for humans has increased dramatically. Most of them are cryptic species belonging to complex species that have replaced traditional single morphospecies. This has occurred in several genera of mucorales and particularly in different ascomycetous genera, such as Aspergillus, Fusarium, Sporothrix and Scedosporium, among others. The correct identification of these species is crucial for a better management of patients, since on many occasions those species show different virulence and different antifungal responses. This review summarises some of the most striking recent taxonomic changes produced in pathogenic fungi.

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.

Lessons from animal studies for the treatment of invasive human infections due to uncommon fungi

Clinical experience in the management of opportunistic infections, especially those caused by less common fungi, is, due to their rarity, very scarce; therefore, the most effective treatments remain unknown. The ever-increasing numbers of fungal infections due to opportunistic fungi have repeatedly proven the limitations of the antifungal armamentarium. Moreover, some of these fungi, such as Fusarium spp. or Scedosporium spp., are innately resistant to almost all the available antifungal drugs, which makes the development of new and effective therapies a high priority. Since it is difficult to conduct randomized clinical trials in these uncommon mycoses, the use of animal models is a good alternative for evaluating new therapies. This is an extensive review of the numerous studies that have used animal models for this purpose against a significant number of less common fungi. A table describing the different studies performed on the efficacy of the different drugs tested is included for each fungal species. In addition, there is a summary table showing the conclusions that can be derived from the analysis of the studies and listing the drugs that showed the best results. Considering the wide variability in the response to the antifungals that the different strains of a given species can show, the table highlights the drugs that showed positive results using at least two parameters for evaluating efficacy against at least two different strains without showing any negative results. These data can be very useful for guiding the treatment of rare infections when there is very little experience or when controversial results exist, or when treatment fails.