Intravenous catheter-associated Malassezia furfur fungemia

Clinical data analysis of 86 patients with invasive infections caused by Malassezia furfur from a tertiary medical center and 37 studies

Objective

Malassezia furfur (M. furfur) is a lipophilic, conditionally pathogenic yeast that mainly causes skin infections, but the reports of related invasive infections are increasing. The aim of this study is to provide clinical data to assist physicians in the management of patients with invasive infections caused by M. furfur.

Methods

A case of pulmonary infection caused by M. furfur in a hematopoietic stem cell transplant patient for aplastic anemia was reported. In addition, the literature on invasive infection by M. furfur published in PubMed and Web of Science in English until 31 July 2022 was reviewed.

Results

Clinical data analysis of 86 patients (from 37 studies and our case) revealed that most of them were preterm (44.2%), followed by adults (31.4%). M. furfur fungemia occurred in 79.1% of the 86 patients, and 45 of them were clearly obtained from catheter blood. Other patients developed catheter-related infections, pneumonia, peripheral thromboembolism, endocarditis, meningitis, peritonitis and disseminated infections. Thirty-eight preterm infants had underlying diseases such as very low birth weight and/or multiple organ hypoplasia. The remaining patients had compromised immunity or severe gastrointestinal diseases. 97.7% of patients underwent invasive procedures and 80.2% received total parenteral nutrition (TPN). Fever, thrombocytopenia and leukocytosis accounted for 55.8%, 38.4% and 24.4% of patients with M. furfur invasive infections, respectively. 69.8% of the patients received antifungal therapy, mainly amphotericin B (AmB) or azoles. Of 84 patients with indwelling catheters, 58.3% underwent the removal of catheters. TPN were discontinued in 30 of 69 patients. The all-cause mortality of 86 patients was 27.9%.

Conclusions

M. furfur can cause a variety of invasive infections. These patients mostly occur in premature infants, low immunity and severe gastrointestinal diseases. Indwelling catheters and TPN infusion are major risk factors. AmB, l-AmB and azoles are the most commonly used agents, and simultaneous removal of the catheter and termination of TPN infusion are important for the treatment of M. furfur invasive infections.

Malassezia spp. Yeasts of Emerging Concern in Fungemia

Malassezia spp. are lipid-dependent yeasts, inhabiting the skin and mucosa of humans and animals. They are involved in a variety of skin disorders in humans and animals and may cause bloodstream infections in severely immunocompromised patients. Despite a tremendous increase in scientific knowledge of these yeasts during the last two decades, the epidemiology of Malassezia spp. related to fungemia remains largely underestimated most likely due to the difficulty in the isolation of these yeasts species due to their lipid-dependence. This review summarizes and discusses the most recent literature on Malassezia spp. infection and fungemia, its occurrence, pathogenicity mechanisms, diagnostic methods, in vitro susceptibility testing and therapeutic approaches.

Evaluation of selected Indian medicinal plants for antagonistic potential against Malassezia spp. and the synergistic effect of embelin in combination with ketoconazole

The genus Malassezia comprises of extremely lipophilic yeasts secreting lipases as a vital factor for survival. They are emerging as opportunistic pathogens in medical microbiology and dermatology by causing recurring and recalcitrant infection. Combinatorial therapy is a constructive way to combat infectious diseases. In that prospect, totally 16 Indian medicinal plants were screened, among which a maximum degree of antimicrobial activity was ascertained in Embelia ribes. Subsequently embelin was identified as the bioactive principle with antagonistic potential by comparative antimicrobial assay and FTIR analysis. The MIC of embelin was determined as 400 μg/ml exhibiting ∼75% of growth inhibition. Further, a fungistatic activity based on anti-lipase potential (65-89%) of embelin has been clearly substantiated by XTT and lipase assay. In addition, embelin exhibited a synergistic effect with the antifungal drug ketoconazole (KTZ) against four different Malassezia spp. with FIC index of 0.5. Therefore, the combinations of embelin and KTZ may represent a promising therapeutic regimen to treat Malassezia infections with subjugated clinical and environmental toxicity. To the best of our knowledge, this is the first report delineating the anti-lipase activity of embelin and in vitro synergistic interaction between embelin and KTZ against Malassezia spp.

Glutathione as a promising anti-hydrophobicity agent against Malassezia spp

The genus Malassezia has recently attracted wide attention in medical microbiology and dermatology as a pathogen. They are lipophilic yeasts possessing high level of cell surface hydrophobicity (CSH). L-glutathione (GSH) is a ubiquitous antioxidant which offers protection against microbial infections. This study is intended to investigate the role of GSH as a potential anti-hydrophobicity agent against Malazessia spp. Microbial adherence to hydrocarbon assay was performed to assess the anti-hydrophobicity activity (AHA) of GSH against four Malassezia spp. The assay revealed that GSH at 400 μg ml(-1) concentration inhibited CSH, ranging from 84% to 95% in M. furfur, M. globosa, M. restricta and M. sympodialis without killing the cells. The AHA of GSH was corroborated by auto-aggregation assay and zeta-potential measurement, through which delayed cell aggregation was observed due to reduction in CSH level and not by modification in cell surface charge. In addition, colony-forming unit assay was performed in which 62-93% of CSH reduction was observed in Malassezia spp. tested. Furthermore, GSH treatment enhanced the sensitivity of Malassezia spp. towards human blood at the rate of 64-72%. The AHA was further confirmed through Fourier transform infrared analysis. Thus, this study portrays GSH as a prospective therapeutic alternative for Malassezia-mediated infections.

Guideline for Prevention of Intravascular-Device–Related Infections

The “Guideline for Prevention of Intravascular Device-Related Infections” is designed to reduce the incidence of intravascular device-related infections by providing an over view of the evidence for recommendations considered prudent by consensus of Hospital Infection Control Practices Advisor y Committee (HICPAC) members. This two-part document updates and replaces the previously published Centers for Disease Control's (CDC) Guideline for Intravascular Infections (Am J Infect Control1983;11:183-199). Part I, “Intravascular Device-Related Infections: An Over view” discusses many of the issues and controversies in intravascular-device use and maintenance. These issues include definitions and diagnosis of catheter-related infection, appropriate barrier precautions during catheter insertion, inter vals for replacement of catheters, intravenous (IV) fluids and administration sets, catheter-site care, the role of specialized IV personnel, and the use of prophylactic antimi-crobials, flush solutions, and anticoagulants. Part II, “Recommendations for Prevention of Intravascular Device-Related Infections” provides consensus recommendations of the HICPAC for the prevention and control of intravascular device-related infections. A working draft of this document also was reviewed by experts in hospital infection control, internal medicine, pediatrics, and intravenous therapy. However, all recommendations contained in the guideline may not reflect the opinion of all reviewers.

The Malassezia genus in skin and systemic diseases

In the last 15 years, the genus Malassezia has been a topic of intense basic research on taxonomy, physiology, biochemistry, ecology, immunology, and metabolomics. Currently, the genus encompasses 14 species. The 1996 revision of the genus resulted in seven accepted taxa: M. furfur, M. pachydermatis, M. sympodialis, M. globosa, M. obtusa, M. restricta, and M. slooffiae. In the last decade, seven new taxa isolated from healthy and lesional human and animal skin have been accepted: M. dermatis, M. japonica, M. yamatoensis, M. nana, M. caprae, M. equina, and M. cuniculi. However, forthcoming multidisciplinary research is expected to show the etiopathological relationships between these new species and skin diseases. Hitherto, basic and clinical research has established etiological links between Malassezia yeasts, pityriasis versicolor, and sepsis of neonates and immunocompromised individuals. Their role in aggravating seborrheic dermatitis, dandruff, folliculitis, and onychomycosis, though often supported by histopathological evidence and favorable antifungal therapeutic outcomes, remains under investigation. A close association between skin and Malassezia IgE binding allergens in atopic eczema has been shown, while laboratory data support a role in psoriasis exacerbations. Finally, metabolomic research resulted in the proposal of a hypothesis on the contribution of Malassezia-synthesized aryl hydrocarbon receptor (AhR) ligands to basal cell carcinoma through UV radiation-induced carcinogenesis.

[Labor epidural analgesia for a woman with a pityriasis versicolor in the lumbar region]

Epidural analgesia is usually contraindicated in case of infection at the site of needle insertion. Tinea versicolor is a benign superficial cutaneous fungal infection caused by the proliferation of a skin commensal yeast of low pathogenicity. We report the case of a pregnant woman with a tinea versicolor in the lumbar region, who benefited from a labor epidural analgesia, realised with reinforced antiseptic measures. No neurological or infectious complication occurred.

Pityriasis versicolor

Pityriasis versicolor is a common superficial fungal infection of the skin. It is caused by Malassezia spp., which are normal human saprophytes. Under certain conditions, both exogenous and endogenous, the fungus can convert from a yeast to a pathogenic mycelial form. This alteration results in mild inflammation of the skin, and in characteristic clinical and histological changes. The taxonomy of Malassezia spp. has recently been modified to include six obligatorily lipophilic species, all of which can be found on human skin, plus one non-obligatorily lipophilic species, which only rarely colonizes human hosts.

LEARNING OBJECTIVES

At the conclusion of this learning activity, participants should be aware of the role of Malassezia in the development of pityriasis versicolor, the clinical and histological changes arising from this dermatosis, and the diagnosis and treatment of this disorder.

Immunology of diseases associated with Malassezia species

Malassezia species are members of the human cutaneous commensal flora, in addition to causing a wide range of cutaneous and systemic diseases in suitably predisposed individuals. Studies examining cellular and humoral immune responses specific to Malassezia species in patients with Malassezia-associated diseases and healthy controls have generally been unable to define significant differences in their immune response. The use of varied antigenic preparations and strains from different Malassezia classifications may partly be responsible for this, although these problems can now be overcome by using techniques based on recent work defining some important antigens and also a new taxonomy for the genus. The finding that the genus Malassezia is immunomodulatory is important in understanding its ability to cause disease. Stimulation of the reticuloendothelial system and activation of the complement cascade contrasts with its ability to suppress cytokine release and downregulate phagocytic uptake and killing. The lipid-rich layer around the yeast appears to be pivotal in this alteration of phenotype. Defining the nonspecific immune response to Malassezia species and the way in which the organisms modulate it may well be the key to understanding how Malassezia species can exist as both commensals and pathogens.

Intracardiac mass complicating Malassezia furfur fungemia

Malassezia furfur is a lipophilic yeast known to colonize indwelling catheters. Although progression to vasculitis and sepsis has been described, it has rarely caused fungemia in adults receiving nutrition via an indwelling catheter. Difficulty in diagnosis occurs as M furfur does not grow on routine culture media unless it is supplemented with fatty acids. We present the first case of M furfur fungemia in an adult, complicated by a pedunculated septic thrombus arising from the superior vena cava and extending into the right atrium. Removal of the catheter, amphotericin-B therapy, and surgical debridement were required for cure.

The spectrum of Malassezia infections in the bone marrow transplant population

A consecutive series of 3044 patients who underwent BMT at the University of Minnesota over a 25 year period were reviewed for the post-transplant occurrence of infection caused by the yeast Malassezia furfur. Six patients, ranging in age from 1 to 54 years, developed Malassezia infections at a median of 59 days post transplant. Five patients were allogeneic transplant recipients; the remaining patient had undergone autologous transplantation. A spectrum of clinical manifestations of Malassezia infection was seen in these patients, including infections of mucosal surfaces and the skin, in addition to catheter-related fungemia. Unlike many of the other more common opportunistic fungal infections in immunocompromised patients, neutropenia and the use of broad-spectrum antimicrobials do not appear to be significant risk factors for Malassezia infections in the BMT population. In addition, disseminated fungal infection despite the presence of fungemia is uncommon. Lastly, the outcome of Malassezia infections in these patients, whether folliculitis, mucosal infection, or fungemia, appears to be quite favorable, in contrast to the poorer outcome with many other fungal infections in BMT patients. Catheter removal and discontinuation of intravenous lipids are important for a successful outcome in fungemic cases.

Medium-chain triglycerides inhibit growth of Malassezia: implications for prevention of systemic infection

OBJECTIVE

Lipophilic Malassezia species may induce catheter-associated sepsis in newborns and immunocompromised patients receiving parenteral lipids. Therefore, we tested whether M. furfur and six other Malassezia species can use commercially available infusions as a lipid source.

DESIGN

Prospective in vitro study.

SETTING

Research laboratory in a university hospital.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

With the exception of M. restricta, all Malassezia species grow on lipid infusions. There are no substantial differences among the different brands. The most rapid growth is shown by M. furfur, which grows better on agar containing a 20% rather than a 10% lipid infusion. Growth of M. furdur and M. sympodialis can be reduced by infusions containing medium-chain triglycerides. Incubated in triglycerides, M. furfur is strongly suppressed by 50% medium-chain triglycerides and M. sympodialis by 8% medium-chain triglycerides. When medium-chain free fatty acids are added to triglycerides, both species can be suppressed by about 1% free fatty acids.

CONCLUSION

Medium-chain triglycerides and medium-chain free fatty acids are toxic for Malassezia species. Commercially available infusions containing medium-chain triglycerides might be used to prevent systemic Malassezia infections.

Molecular typing of Malassezia species with PFGE and RAPD

The currently recognized seven species of Malassezia all have different karyotypes which do not vary intraspecifically, except in M. furfur which displayed two different karyotypes. In contrast, random amplified polymorphic DNA (RAPD) typing showed the presence of genetic variation in all species. It is concluded that karyotype analysis is useful for species identification, and RAPD typing can be used in epidemiological investigations.

Identification of Candida species by randomly amplified polymorphic DNA fingerprinting of colony lysates

We have characterized a method that produces simple yet diagnostic fingerprints that are unique to isolates of Candida species. DNA from individual colonies can be amplified from crude single-colony lysates. Randomly amplified polymorphic DNA (RAPD) fingerprints generated from a single primer correctly identified the species of most (>98%) of the isolates identified with CHROMagar Candida plates as non-Candida albicans Candida species. RAPD fingerprints were much more informative than the plates, since they distinguished between all tested species and required less time. Most (91%) of these identifications agreed with those assigned by API 20C tests. In almost every incident of species identity mismatch, electrophoretic karyotyping showed that the RAPD fingerprint was correct. This underscores the improved objectivity and reliability of this method over those of conventional diagnostic tools. The identities of approximately 30% of C. albicans isolates identified in clinical laboratories by positive germ tube tests are not verified by either testing on CHROMagar Candida plates or RAPD fingerprinting. Data suggest that clinical isolates conventionally identified as C. albicans in clinical settings are heterogeneous, consisting of both misidentified and atypical yeasts. RAPD fingerprints obtained from primary culture plate colonies allows for rapid, highly accurate determinations of Candida species, hence permitting earlier selection of appropriate antifungal agents in the clinical setting.

A prospective survey for central line skin-site colonization by the pathogen Malassezia furfur among hospitalized adults receiving total parenteral nutrition

BACKGROUND

Over 50 case reports suggest that Malassezia furfur is an emerging systemic pathogen in neonates who receive IV lipid emulsions. Because isolation of this fungus requires special culture techniques, which are not routinely used, the authors of many case reports of M. furfur infections in adults question whether infections caused by this organism are being underdiagnosed in older patients.

METHODS

Catheter insertion site colonization rates in adults receiving total parenteral nutrition (TPN) were prospectively evaluated in 149 hospitalized patients with 928 cultures handled specifically for M. furfur detection. Positive control samples consisted of M. furfur cultures in neonates and in adults, who had not been enrolled in the study, and of a separate positive culture obtained from a skin site inoculated with M. furfur.

RESULTS

M. furfur was not cultured from any of the 928 study samples (95% confidence interval [CI] -0.4% to +0.4%).

CONCLUSIONS

These results suggest that M. furfur is less of a threat to hospitalized adults receiving TPN than has been otherwise postulated. These data do not support the inclusion of special cultures for M. furfur in routine skin-site surveillance programs among hospitalized adults receiving TPN.

Management of catheter-related bacteremia and fungemia in patients on total parenteral nutrition

To diminish the risk of serious complications from catheter-related bacteremias or fungemias, an optimized diagnosis and antimicrobial therapy is essential and early catheter removal should be considered. Prompt removal of the catheter and targeted antimicrobial treatment remains a common approach for febrile episodes in patients on total parenteral nutrition. However, novel tools allow diagnosis of catheter-related infections with the catheter in situ. Moreover, many of the established catheter-related infections caused by coagulase-negative staphylococci can successfully be treated with the catheter still in place. The use of these advanced management options depends widely on the resource of the microbiology laboratory as well as the type of catheter and severity of the patient's disease.

Fungal infections in lung and heart-lung transplant recipients. Report of 9 cases and review of the literature

We reviewed the pattern and incidence of fungal infections in patients undergoing lung and heart-lung transplantation at Duke University Medical Center from September 1992 until August 1995, and present here 9 illustrative cases. Of the 73 lung and heart-lung transplant recipients studied, 59 (81%) had positive fungal cultures at some point after transplantation. The cases presented here illustrate that lung transplant recipients are predisposed to a wide variety of fungal infections. The clinical pattern of these infections ranges from asymptomatic to rapidly progressive fatal disease. In addition to the reactivation of previous fungal infections and recent exposure to new environmental sources, the donor lung itself can be the source of fungal infection, as we showed by using molecular epidemiology techniques. Because of the associated morbidity and mortality, efforts should be directed at investigating prophylactic antifungal regimens in lung transplant recipients. Preliminary reports on the use of itraconazole and aerosolized amphotericin B have been encouraging. Prospective randomized studies are needed to assess the safety and cost effectiveness of different regimens. Fungal infections in patients after lung transplantation can significantly impede recovery and lead to substantial mortality.

Human infections due to Malassezia spp

The genus Malassezia contains three member species: Malassezia furfur and Malassezia sympodialis, both obligatory lipophilic, skin flora yeasts of humans, and Malassezia pachydermatis, a nonobligatory lipophilic, skin flora yeast of other warm-blooded animals. Several characteristics suggest the basidiomycetous nature of these yeasts, although a perfect stage has not been identified. Classically, these organisms are associated with superficial infections of the skin and associated structures, including pityriasis versicolor and folliculitis. Recently, however, they have been reported as agents of more invasive human diseases including deep-line catheter-associated sepsis. The latter infection occurs in patients, primarily infants, receiving parenteral nutrition (including lipid emulsions) through the catheter. The lipids presumably provide growth factors required for replication of the organisms. It is unclear how deep-line catheters become colonized with Malassezia spp. Skin colonization with M. furfur is common in infants hospitalized in neonatal intensive care units, whereas colonization of newborns hospitalized in well-baby nurseries and of older infants is rarely observed. Catheter colonization, which may occur without overt clinical symptoms, probably occurs secondary to skin colonization, with the organism gaining access either via the catheter insertion site on the skin or through the external catheter hub (connecting port). There is little information on the colonization of hospitalized patients by M. sympodialis or M. pachydermatis. Diagnosis of superficial infections is best made by microscopic examination of skin scrapings following KOH, calcofluor white, or histologic staining. Treatment of these infections involves the use of topical or oral antifungal agents, and it may be prolonged. Diagnosis of Malassezia catheter-associated sepsis requires detection of the organism in whole blood smears or in buffy coat smears of blood drawn through the infected catheter or isolation of the organism from catheter or peripheral blood or the catheter tip. Culture of M. furfur from blood is best achieved with Isolator tubes and plating onto a solid medium supplemented with a lipid source. Appropriate treatment of patients requires removal of the infected catheter with or without temporary stoppage of lipid emulsions; administration of antifungal therapeutic agents does not appear to be necessary. Because many patients who develop Malassezia catheter-associated sepsis have severe underlying illnesses, caution must be exercised in attributing all clinical deterioration to Malassezia infection. Our better understanding of how these organisms cause disease awaits the development of a useful typing scheme for epidemiologic studies and further studies on microbial virulence factors and the role of the immune response in pathogenesis.

Pityrosporum folliculitis in the Philippines: diagnosis, prevalence, and management

Sixty-eight typical cases were studied to define the course of Pityrosporum folliculitis in a tropical setting. Contrary to reports in the literature, we found Pityrosporum folliculitis to be polymorphic. The "molluscoid" comedopapule was the most characteristic and common lesion, and it yielded consistently high spore counts. The face was commonly involved. To establish the diagnosis, we used direct microscopy of potassium hydroxide/Parker blue-black ink mounts of the lower poles of comedonal plugs. Pityrosporum folliculitis is common in the Philippines, although our adult controls had a low incidence of skin carriage of Pityrosporum orbiculare on the face compared with those reported in the West. Pityrosporum folliculitis coexisted with acne vulgaris in 56% of patients, and the addition of antimycotics to the acne regimen produced dramatic clearing of lesions.

Malassezia furfur colonization of neonates in an intensive care unit

We studied Malassezia furfur colonization of neonates in the neonatal intensive care unit (NICU) and found that the rate was astonishingly high as compared to the previous studies. In very low birth weight (less than 1,000 g) infants we recorded a colonization rate of 80%, and 4% infants with a birth weight greater than 2,000 g. Under 10 day's hospitalization the rate was 11%, and it was 70% after 20 days spent in the unit. Among the infants with the birth weight less than 1,700 g, antibiotic therapy was recorded as a significant risk factor for colonization. In the infants with a greater birth weight, the colonization rate was independent from the risk factors studied. M. furfur colonization could not be linked with occurrence of any symptoms of signs recorded and colonization by M. furfur was so common in NICU that the predictive value of surveillance cultures is poor.

Bacteremia and fungemia in the immunocompromised patient

Considerable changes have occurred during the 1980s in the clinical nature and diagnosis of bacteremia and fungemia in the immunocompromised patient. Cancer patients with prolonged neutropenia, many with indwelling catheters, and AIDS patients with both T-cell and B-cell deficiencies have changed the spectrum of organisms causing septicemia. There has been a shift to infection with gram-positive bacteria, including mycobacteria, and water-borne organisms, including Acinetobacter spp. and Pseudomonas spp. New blood culture systems, including a lysis-centrifugation system and radiometric methods utilizing resin broth media, remove antagonistic antimicrobial agents, and the lysis-centrifugation system routinely provides quantitation of organisms from the blood. Quantitation has been used to identify sources of infection, to differentiate contamination from true infection, and to monitor the course of antibiotic treatment.