The Concept of Ecthyma Gangrenosum Illustrated by a Fusarium oxysporum Infection in an Immunocompetent Individual

Cutaneous Hyalohyphomycosis and Its Atypical Clinical Presentations in Immunosuppressed Patients

There has been a substantial increase in the number of cases of invasive fungal infections worldwide, which is associated with a growing number of immunosuppressed patients and a rise in antifungal resistance. Some fungi that were previously considered harmless to humans have become emerging pathogens. One of them is Purpureocillium lilacinum, a ubiquitous filamentous fungus commonly found in the environment, especially in the air and soil. P. lilacinum belongs to a bigger group of hyaline fungi that cause hyalohyphomycosis, a fungal infection caused by fungi with colorless hyphae. Although this is a heterogeneous group of fungi, there are similarities regarding their ubiquity, ways of transmission, affected patients, and difficulties in diagnostics and treatment. In hyalohyphomycosis, the skin is one of the most affected organs, which is why the involvement of dermatologists is crucial for the initial assessment, since the timely recognition and early diagnosis of this condition can prevent life-threatening infections and death. In this review, we covered cutaneous hyalohyphomycosis caused by P. lilacinum and other fungi in the same group, including Fusarium, Penicilium, Scedosporium, Scopulariopsis, Acremonium, and Trichoderma genera.

Multidisciplinary management of disseminated Exophiala dermatitidis mycosis in an infant with mixed phenotype acute leukemia: a case report

Background

Exophiala dermatitidis is a dematiaceous fungus isolated from various environmental sources. Systemic E. dermatitidis infections can lead to fatal outcomes, and treatment has not yet been standardized. Although E. dermatitidis is also known to cause cutaneous infection, it has not been previously reported to appear as ecthyma gangrenosum (EG), an uncommon cutaneous lesion in neutropenic patients that is mainly caused by Pseudomonas aeruginosa.

Case presentation

A 2-month-old male infant with mixed-phenotype acute leukemia presented with prolonged fever unresponsive to antibacterial and antifungal agents during myelosuppression due to remission induction therapy. He also presented with skin lesions on the left wrist and left lower quadrant of the abdomen. The abdominal lesion gradually turned black and necrotic, which was consistent with the findings of the EG. E. dermatitidis was isolated from the blood, stool, wrist skin, and endotracheal aspirate. During hematopoietic recovery, consolidation in both lungs was evident. Multiagent antifungal treatment failed to eliminate E. dermatitidis from blood. In order to salvage the central venous catheter, ethanol lock therapy (ELT) was adopted, following which the blood culture became negative. The abdominal lesion that evolved as a necrotic mass connecting the small intestine and subcutaneous tissue adjacent to the skin was surgically resected. After these interventions, the general condition improved.

Conclusion

Disseminated E. dermatitidis mycosis in the neutropenic infant was successfully managed with a multidisciplinary treatment consisting of multiagent antifungal treatment, ELT, and surgery.

Recent developments in less known and multi-resistant fungal opportunists

Fungal infections have increased in recent years due to host factors, such as oncohaematological and transplant-related disorders, immunosuppressive therapy, and AIDS. Additionally, molecular and proteomic facilities have become available to identify previously unrecognizable opportunists. For these reasons, reports on less-known and recalcitrant mycoses, such as those caused by black fungi, hyaline filamentous fungi, coelomycetes, Mucorales, and non-Candida yeasts have emerged. In this review, novel taxonomy in these groups, which often are multi-resistant to one or several classes of antifungals, is discussed. Clinical presentations, diagnosis and current treatment of some major groups are summarised.

Ecthyma gangrenosum: The critical role of biofilms and other mechanisms of antibiotic resistance and implications for management

Ecthyma gangrenosum is a rare cutaneous infection that occurs classically in immunocompromised patients with Pseudomonas aeruginosa bacteremia and is associated with a high mortality rate. Causative pathogens may exhibit various antibiotic evasion mechanisms, and thus, treatment may be challenging. We present a case of ecthyma gangrenosum in association with an implantable port in which cultures confirmed ten unique strains of Pseudomonas aeruginosa, highlighting the ability of this pathogen to form biofilms, rapidly mutate and ultimately evade antibiotic therapy. Dermatologists play a key role in the prompt diagnosis of this life-threatening condition, and a thorough understanding of pathogenic mechanisms is critical in selecting an efficacious treatment regimen.

Phylogenetic Analysis of Clinically Relevant Fusarium Species in Iran

Fungi of the genus Fusarium are well known as major plant pathogens but also cause a broad spectrum of human infections. Sixty-three clinical isolates, collected during 2014-2017, were identified using a part of the TEF1 gene as barcoding marker. Fusarium fujikuroi species complex (FFSC, n = 41, 65%) showed to be the dominant etiological agent, followed by F. solani species complex (FSSC, n = 14, 22%) and F. oxysporum species complex (FOSC, n = 7, 11%). There was one strain belonging to F. lateritium species complex (FLSC, n = 1, 1.5%). For final identification, a phylogenetic tree was constructed including the type strains of each species complex. Most cases of fusariosis were due to nail infection (n = 38, 60.3%), followed by keratitis (n = 22, 34%). Fusarium infections are difficult to be treated due to their intrinsic resistance to different azoles; however, accurate and fast identification of etiological agents may enhance management of the infection. We present the first phylogenetic study on clinical Fusarium spp. from Iran.

Ecthyma Gangrenosum of Scrotum in a Patient with Neutropenic Fever: A Case Report

BACKGROUND Ecthyma gangrenosum is an uncommon cutaneous infection commonly caused by Pseudomonas aeruginosa affecting typically immunocompromised patients. The presence of ecthyma gangrenosum can be associated with severe systemic infection often with a fatal prognosis. Most cases of ecthyma gangrenosum occur around the axilla, buttocks, and limbs; the scrotum is rarely affected. CASE REPORT A 68-year-old male with previously diagnosed acute myeloid leukemia, presented with left scrotal pain, fever, and rigors. Physical examination showed 2 ulcerating lesions with central black eschars surrounded by erythematous halos on the superior aspect of the left scrotum. Diagnosis of ecthyma gangrenosum was confirmed as both blood and lesion cultures showed growth of P. aeruginosa. After early empiric antibiotic treatment, the lesions significantly improved, and no sign of recurrence or new lesions was noticed. CONCLUSIONS Ecthyma gangrenosum should be considered in the differential diagnosis of ulcerating lesions of the scrotum. An early diagnosis and aggressive antibiotic treatment are imperative for resolution of this infection.

The Curious Case of "Case Report" of Infections Caused by Human and Animal Fungal Pathogens: An Educational Tool, an Online Archive, or a Format in Need of Retooling

Case reports describe the unusual occurrence and complications of diseases, diagnostic challenges, and notable therapeutic successes. Some journals have discontinued the case reports, while new case report journals have appeared in recent years. During the eightieth anniversary of Mycopathologia, it is fitting to examine the relevance of the case report since the journal continues to traverse the boundaries of basic and clinical sciences. A random sample of recent case reports and other articles were selected from Mycopathologia. Springer Nature individual article download statistics, and Google Scholar and Scopus citations numbers were compared to assess the reader access and bibliometric impact of case reports. Our analysis indicated that the case report format continues to be a vital element of publication in a cross-disciplinary journal such as Mycopathologia. Medical and veterinary case reports covering fungal pathogens are widely read as evident from their download numbers. The download numbers have a positive correlation with the completeness of the report, the topics and geographic origin of reports have a neutral influence, and the recency leads to lower downloads. There is no discernible trend between the download numbers and the citations of case reports as measured by Google Scholar and Scopus. A specially designed checklist for Mycopathologia case reports and new format MycopathologiaIMAGES are being introduced to improve the quality and relevance of case reports further.

Epitypification of Fusarium oxysporum - clearing the taxonomic chaos

Fusarium oxysporum is the most economically important and commonly encountered species of Fusarium. This soil-borne fungus is known to harbour both pathogenic (plant, animal and human) and non-pathogenic strains. However, in its current concept F. oxysporum is a species complex consisting of numerous cryptic species. Identification and naming these cryptic species is complicated by multiple subspecific classification systems and the lack of living ex-type material to serve as basic reference point for phylogenetic inference. Therefore, to advance and stabilise the taxonomic position of F. oxysporum as a species and allow naming of the multiple cryptic species recognised in this species complex, an epitype is designated for F. oxysporum. Using multi-locus phylogenetic inference and subtle morphological differences with the newly established epitype of F. oxysporum as reference point, 15 cryptic taxa are resolved in this study and described as species.

Antifungal Susceptibility Testing of Fusarium: A Practical Approach

In vitro susceptibility testing of Fusarium is becoming increasingly important because of frequency and diversity of infections and because resistance profiles are species-specific. Reference methods for antifungal susceptibility testing (AFST) are those of Clinical and Laboratory Standards Institute (CLSI) and European Committee on Antimicrobial Susceptibility (EUCAST), but breakpoints (BPs) have not yet been established. One of the problems is that phylogenetic distances between Fusarium species are much smaller than between species of, e.g., Candida. Epidemiological cutoff values (ECVs) for some Fusarium species have been determined in order to differentiate wild-type from non-wild-type isolates. In clinical routine, commercially available assays such as Etest, Sensititre or others provide essential agreement with reference methods. Our objective is to summarize antifungal susceptibility testing of Fusarium genus in the clinical laboratory: how to do it, when to do it, and how to interpret it.

Reduced Multidrug Susceptibility Profile Is a Common Feature of Opportunistic Fusarium Species: Fusarium Multi-Drug Resistant Pattern

The resistance among various opportunistic Fusarium species to different antifungal agents has emerged as a cause of public health problems worldwide. Considering the significance of multi-drug resistant (MDR), this paper emphasizes the problems associated with MDR and the need to understand its clinical significance to combat microbial infections. The search platform PubMed/MEDLINE and a review of 32 cases revealed a common multidrug-resistant profile exists, and clinically relevant members of Fusarium are intrinsically resistant to most currently used antifungals. Dissemination occurs in patients with prolonged neutropenia, immune deficiency, and especially hematological malignancies. Amphotericin B displayed the lowest minimum inhibitory concentrarions (MICs) followed by voriconazole, and posaconazole. Itraconazole and fluconazole showed high MIC values, displaying in vitro resistance. Echinocandins showed the highest MIC values. Seven out of ten (70%) patients with neutropenia died, including those with fungemia that progressed to skin lesions. Clinical Fusarium isolates displayed a common MDR profile and high MIC values for the most available antifungal agents with species- and strain-specific differences in antifungal susceptibility. Species identification of Fusarium infections is important. While the use of natamycin resulted in a favorable outcome in keratitis, AmB and VRC are the most used agents for the treatment of fusariosis in clinical settings.