Successful treatment of a primary cutaneous zygomycosis caused by Absidia corymbifera in a premature newborn

Chitosan Production by Fungi: Current State of Knowledge, Future Opportunities and Constraints

Conventionally, the commercial supply of chitin and chitosan relies on shellfish wastes as the extraction sources. However, the fungal sources constitute a valuable option, especially for biomedical and pharmaceutical applications, due to the batch-to-batch unsteady properties of chitin and chitosan from conventional ones. Fungal production of these glycans is not affected by seasonality enables accurate process control and, consequently, more uniform properties of the obtained product. Moreover, liquid and solid production media often are derived from wastes, thus enabling the application of circular economy criteria and improving the process economics. The present review deals with fungal chitosan production processes focusing on waste-oriented and integrated production processes. In doing so, contrary to other reviews that used a genus-specific approach for organizing the available information, the present one bases the discussion on the bioprocess typology. Finally, the main process parameters affecting chitosan production and their interactions are critically discussed.

Risk Assessment for Molds in the Vicinity of a Child Requiring Peritoneal Dialysis Living in a Rural Northern German Area

As well as severe immunosuppression, other predisposing factors may facilitate invasive mycosis caused by molds. Chronic kidney disease and the resulting peritoneal dialysis have been reported as factors putting patients at risk of fungal infections from environmental sources. We describe an environmental investigation undertaken to guide exposure prevention for a peritoneal dialysis patient with transient colonization of her nostrils by Lichtheimia corymbifera in a rural area of northern Germany. Systematic screening for airborne and surface-deposited molds enabled targeted recommendations to be made, although Lichtheimia corymbifera itself was not grown from the collected environmental samples. This communication is intended to illustrate how such an investigation can be performed on the basis of the environmental distribution of the molds and how preventive recommendations can be derived from the results.

Mucormycoses caused by Lichtheimia species

Mucormycoses are life-threatening infections with fungi from the order Mucorales (Mucoromycotina). Although mucormycoses are uncommon compared to other fungal infections, e.g. aspergillosis and candidiasis, the number of cases is increasing especially in immunocompromised patients. Lichtheimia (formerly Absidia) species represent the second to third most common cause of mucormycoses in Europe. This mini review presents current knowledge about taxonomy and clinical relevance of Lichtheimia species. In addition, clinical presentation and risk factors will be discussed. Proper animal infection models are essential for the understanding of the pathogenesis and the identification of virulence factors of fungal pathogens. To date, several animal models have been used to study Lichtheimia infection. A brief overview of the different models and the main conclusions from the infection experiments is summarised in this review.

Green synthesis approach: extraction of chitosan from fungus mycelia

Chitosan, copolymer of glucosamine and N-acetyl glucosamine is mainly derived from chitin, which is present in cell walls of crustaceans and some other microorganisms, such as fungi. Chitosan is emerging as an important biopolymer having a broad range of applications in different fields. On a commercial scale, chitosan is mainly obtained from crustacean shells rather than from the fungal sources. The methods used for extraction of chitosan are laden with many disadvantages. Alternative options of producing chitosan from fungal biomass exist, in fact with superior physico-chemical properties. Researchers around the globe are attempting to commercialize chitosan production and extraction from fungal sources. Chitosan extracted from fungal sources has the potential to completely replace crustacean-derived chitosan. In this context, the present review discusses the potential of fungal biomass resulting from various biotechnological industries or grown on negative/low cost agricultural and industrial wastes and their by-products as an inexpensive source of chitosan. Biologically derived fungal chitosan offers promising advantages over the chitosan obtained from crustacean shells with respect to different physico-chemical attributes. The different aspects of fungal chitosan extraction methods and various parameters having an effect on the yield of chitosan are discussed in detail. This review also deals with essential attributes of chitosan for high value-added applications in different fields.

Invasive Mold Infections in Pediatric Cancer Patients Reflect Heterogeneity in Etiology, Presentation, and Outcome: A 10-Year, Single-Institution, Retrospective Study

BACKGROUND

There is scarcity of data regarding invasive mold infections (IMIs) in children with cancer.

METHODS

We retrospectively identified patients (18 years old or younger) with malignant disease who developed proven or probable IMIs (European Organization for Research on the Treatment of Cancer/Mycoses Study Group criteria) during a 10-year period (1998-2008). We reviewed their risk factors and clinical characteristics and assessed their crude mortality rates and treatment outcomes 12 weeks after IMI diagnosis.

RESULTS

Forty-eight patients (30 males) were identified, 30 (63%) of whom had a proven IMI. The most prevalent mold were Aspergillus species (40%), followed by Mucorales (20%) and Fusarium species (11%). Acute leukemia was the most common underlying malignancy (39 patients, [81%]). Twenty-three (59%) of them had refractory leukemia. Neutropenia was present at the day of IMI diagnosis in 67% of the patients. Sixty-two percent of the patients received prior corticosteroids. The dominant site of infection was the lungs (79%), followed by skin (29%) and sinuses (10%). Seventy-one percent of patients had radiological findings suggestive of fungal pneumonia (either nodules or masses). The mainstay of antifungal therapy was a lipid formulation of amphotericin B. Antifungal therapy resulted in 54% response rate (33% complete) at 12 weeks. The crude 12-week mortality rate was 31%. Logistic regression analysis demonstrated that monocytopenia (P = .013), malnutrition (P = .012), and intensive care admission in the month prior to IMI diagnosis (P = .027) were risk factors for death within 12 weeks.

CONCLUSIONS

Although Aspergillus spp. was the most common mold in our pediatric cancer population, the epidemiology of the IMIs was diverse. Adults and children share similar risk factors for and epidemiology of IMIs.

Zygomycosis in neonates: an uncommon but life-threatening infection

We systematically reviewed all published cases of zygomycosis, an increasingly important infection with high mortality, in neonates. We searched PubMed and individual references for English publications of single cases or case series of neonatal (0 to 1 month) zygomycosis. Cases were included if they fulfilled prespecified criteria. Fifty-nine cases were published through July 2007. Most of the infants (77%) were premature. The most common sites of zygomycosis were gastrointestinal (54%) and cutaneous (36%) diseases. This pattern differs from sinopulmonary and rhinocerebral patterns of older children. Fifty-six percent of cases were diagnosed by histology only and 44% by histology and culture. RHIZOPUS spp. were isolated from 18/25 (72%) cases. Thirty-seven percent of patients received no antifungal therapy. Thirty-two (54%) neonates underwent surgery with (39%) or without (15%) antifungal agents. Overall mortality was 64%. A higher fraction of neonates treated with amphotericin B and surgery survived than those who received no therapy (70% versus 5%). Zygomycosis is a life-threatening infection in neonates with a distinct pattern of gastrointestinal and cutaneous involvement and high mortality. Combination of amphotericin B and surgery was common management strategy in survivors.

Diagnosis and treatment of cutaneous zygomycosis

Cutaneous zygomycosis is a rare but severe fungal infection with high risk of dissemination. Early recognition, deep surgical biopsy for diagnosis, aggressive treatment with repeated surgical debridement, and targeted pharmacotherapy are essential and can prevent dissemination and fatal outcome. We present case reports of 2 patients.

Cutaneous mucormycosis in a young, immunocompetent girl

We report a case of cutaneous mucormycosis in a healthy, immunocompetent young girl (age 14 years). The patient had a 5-year history of a slowly enlarging, erythematous plaque with slight elevated, scaling, circinate borders on the right thigh. Histopathology showed a granulomatous infiltrate with broad, pale, non-septate hyphae. Mycological study identified Mucor hiemalis (Wehmer).

Neonatal cutaneous fungal infections

PURPOSE OF REVIEW

Cutaneous fungal infections are not uncommon in newborns and are seen in premature or otherwise immunocompromised neonates as well as in healthy full-term neonates. Healthy newborns can develop clinical manifestations as a result of infection with Candida species or as a result of skin colonization with Malassezia species; cutaneous infection with other fungal pathogens is rare. Immunocompromised and premature neonates, however, are susceptible to infection with opportunistic pathogens and are also at higher risk for invasive infection with common pathogens such as Candida. This review discusses the fungal species associated with cutaneous fungal infection in neonates, emphasizes the relevant clinical features, and also reviews the use of newer antifungal agents, including lipid-associated amphotericin B, voriconazole, and caspofungin.

RECENT FINDINGS

Neonatal cutaneous infections with opportunistic fungal pathogens, including Aspergillus and the Zygomycetes, have been reported with increasing frequency as advances in neonatal care have improved the survival rate in very low birthweight neonates. Although these infections are frequently fatal, survival in some neonates has been reported with the use of aggressive surgical debridement and systemic antifungal therapy. Newer antifungal agents, including voriconazole and caspofungin, show promise in the treatment of potentially fatal fungal infections in neonates.

SUMMARY

Cutaneous fungal infections in neonates range from generally benign conditions such as congenital candidiasis and neonatal cephalic pustulosis to potentially fatal infections with opportunistic pathogens in very low birthweight or immunocompromised neonates. The prompt recognition and appropriate treatment of cutaneous fungal disease in neonates is critical to the prevention of adverse outcomes.

Hypodermite granulomateuse révélatrice d’une mucormycose chez une malade immunodéprimée

INTRODUCTION

Mucormycosis is an exceptional opportunist fungal infection, despite the ubiquitous nature of its pathogenic agents. It is sometimes revealed by primary cutaneous involvement and its prognosis is bad in the case of visceral dissemination. Our observation illustrates the need for early diagnosis and treatment of this infection.

OBSERVATION

An immunodepressed, 45 year-old woman, had developed necrotic hypodermitis lesions on the lower limbs. The skin biopsy led to the diagnosis of mucormycosis. Despite treatment with liposomal amphotericin, the fungal infection worsened, spread to the organs (lungs and brain) and the patient died.

DISCUSSION

This case report underlines the potential severity of mucormycosis, which is presently emerging in the onco-hematological field. The infection is sometimes revealed by inaugural ulcerated and/or necrotic cutaneous lesions. Its diagnosis must be evoked early so that salvage medical-surgical treatment can be initiated.