A Case of Disseminated Infection with Skin Manifestation due to Non-neoformans and Non-gattii Cryptococcus in a Patient with Refractory Acute Myeloid Leukemia

Molecular identification, genotypic heterogeneity and comparative pathogenicity of environmental isolates of Papiliotrema laurentii

Introduction. Papiliotrema laurentii, formerly Cryptococcus laurentii, is typically isolated from environmental sources, but also occasionally from clinical specimens. Other close relatives may be misidentified as P. laurentii by phenotypic methods. P. laurentii usually lacks melanin; however, melanin-forming strains have also been isolated.

Hypothesis/Gap Statement. Although melanin production by encapsulated budding yeasts is considered a major virulence factor, the comparative pathogenicity of melanin-forming and non-melanized environmental strains of P. laurentii has rarely been studied.

Aim. We performed phenotypic and molecular identification and determined the genotypic heterogeneity among P. laurentii isolates. We also studied the pathogenicity of melanin-forming and non-melanized strains in normal and immunosuppressed mice.

Methodology. Eleven environmental isolates were tested for their identity by Vitek2 and/or ID32C systems, and by PCR-sequencing of the internal transcribed spacer (ITS) region and D1/D2 domains of ribosomal DNA (rDNA). Genotypic heterogeneity was studied by sequence comparisons. The pathogenicity of melanized and non-melanized P. laurentii strains was studied in intravenously infected normal and immunosuppressed BALB/c mice.

Results. Phenotypic methods identified seven of the environmental isolates, while PCR-sequencing of the ITS region and D1/D2 domains of rDNA detected two and five isolates, respectively, as P. laurentii. Sequence comparisons demonstrated genotypic heterogeneity among P. laurentii. The remaining four environmental isolates yielded expected results. None of the normal mice infected with 105 cells of melanized/non-melanized P. laurentii strains died. Infection of immunosuppressed mice with 107 cells caused higher mortality with non-melanized P. laurentii, while viable counts in brain/lung tissue were higher in mice infected with a melanized strain and were detectable for up to 14 days.

Conclusion. Phenotypic methods lacked specificity, but PCR-sequencing of D1/D2 domains correctly identified P. laurentii and sequence comparisons demonstrated the genotypic heterogeneity of the isolates. Both melanized and non-melanized strains at a higher dose caused mortality in immunosuppressed mice and persisted in brain/lung tissue up to 14 days post-infection.

Cryptococcal infection in haematologic malignancies and haematopoietic stem cell transplantation

This review summarises both the recent and relevant studies about cryptococcal infections in haematologic malignancies and haematopoietic stem cell transplantation. Although uncommon in this patient population, this infection carries a high mortality, especially if left untreated. Given the limited data, we draw some conclusions with respect to management from the solid organ transplantation and HIV-infected literature. Herein, we discuss cryptococcosis with a particular attention to its background, epidemiology, risk factors, clinical presentation, diagnosis, treatment and prevention in this group.

Cryptococcosis in Hematopoietic Stem Cell Transplant Recipients: A Rare Presentation Warranting Recognition

Cryptococcosis, a life-threatening mycosis caused mainly by Cryptococcus neoformans, appears to be distinctly rare in hematopoietic stem cell transplant (HSCT) recipients. When it occurs, this fungal infection is a major limitation for a successful transplant. This review comprehensively analyses 24 cases, reported in the literature, of patients with haematological malignancies including leukemias, multiple myeloma, and lymphomas, as indication for HSCT, who presented with cryptococcosis after transplantation. Of the 24 cases, 11 each occurred in patients receiving allogeneic and autologous stem cell transplants, from bone marrow, peripheral blood, and umbilical cord blood. HSCT recipients were slightly more often male, and the age of the patients ranged from 12 to 74 years. Antifungal prophylaxis was reported in most cases. Clinical manifestations of cryptococcal disease included more frequently central nervous system involvement followed by fungaemia, disseminated infection, pulmonary cryptococcosis, cerebellitis, and diarrhea. Diagnosis differed depending on the clinical presentation but habitually included cryptococcal antigen assay, India ink, and culture. Notably, not only C. neoformans but also C. albidus, C. terreus, C. laurentii, and C. adeliensis were identified as the causal species, the last two including strains resistant to fluconazole. Amphotericin B, alone or in combination, was the most common antifungal drug used for the treatment of cryptococcosis in HSCT recipients. Due to the small number of cases, it was not possible to establish if mortality rate, which was the same as survival rate, depends on the effect of the immunosuppressive regimen, the site of cryptococcal infection, and/or the antifungal therapy used to control the mycosis. Although uncommon, the recognition of cryptococcal disease in stem cell transplant is essential for a timely and adequate treatment, improved prognosis, reduced morbidity and mortality, and successful transplantation.

An Overview of the Management of the Most Important Invasive Fungal Infections in Patients with Blood Malignancies

In patients with hematologic malignancies due to immune system disorders, especially persistent febrile neutropenia, invasive fungal infections (IFI) occur with high mortality. Aspergillosis, candidiasis, fusariosis, mucormycosis, cryptococcosis and trichosporonosis are the most important infections reported in patients with hematologic malignancies that undergo hematopoietic stem cell transplantation. These infections are caused by opportunistic fungal pathogens that do not cause severe issues in healthy individuals, but in patients with hematologic malignancies lead to disseminated infection with different clinical manifestations. Prophylaxis and creating a safe environment with proper filters and air pressure for patients to avoid contact with the pathogens in the surrounding environment can prevent IFI. Furthermore, due to the absence of specific symptoms in IFI, rapid and accurate diagnosis reduces the mortality rate of these infections and using molecular techniques along with standard mycological methods will improve the diagnosis of disseminated fungal infection in patients with hematologic disorders. Amphotericin B products, extended-spectrum azoles, and echinocandins are the essential drugs to control invasive fungal infections in patients with hematologic malignancies, and according to various conditions of patients, different results of treatment with these drugs have been reported in different studies. On the other hand, drug resistance in recent years has led to therapeutic failures and deaths in patients with blood malignancies, which indicates the need for antifungal susceptibility tests to use appropriate therapies. Life-threatening fungal infections have become more prevalent in patients with hematologic malignancies in recent years due to the emergence of new risk factors, new species, and increased drug resistance. Therefore, in this review, we discuss the different dimensions of the most critical invasive fungal infections in patients with hematologic malignancies and present a list of these infections with different clinical manifestations, treatment, and outcomes.

Clinical diversity of invasive cryptococcosis in AIDS patients from central China: report of two cases with review of literature

Background

Although antiretroviral therapy (ART) has greatly improved the prognosis of acquired immunodeficiency syndrome (AIDS) patients globally, opportunistic infections (OIs) are still common in Chinese AIDS patients, especially cryptococcosis.

Case presentation

We described here two Chinese AIDS patients with cryptococcal infections. Case one was a fifty-year-old male. At admission, he was conscious and oriented, with papulonodular and umbilicated skin lesions, some with ulceration and central necrosis resembling molluscum contagiosum. The overall impression reminded us of talaromycosis: we therefore initiated empirical treatment with amphotericin B, even though the case history of this patient did not support such a diagnosis. On the second day of infusion, the patient complained of intermittent headache, but the brain CT revealed no abnormalities. On the third day, a lumbar puncture was performed. The cerebral spinal fluid (CSF) was turbid, with slightly increased pressure. India ink staining was positive, but the cryptococcus antigen latex agglutination test (CrAgLAT: IMMY, USA) was negative. Two days later, the blood culture showed a growth of Cryptococcus neoformans, and the same result came from the skin culture. We added fluconazole to the patient’s treatment, but unfortunately, he died three days later.

Case two was a sixty-four-year-old female patient with mild fever, productive cough, dyspnea upon movement, and swelling in both lower limbs. The patient was empirically put on cotrimoxazole per os and moxifloxacin by infusion. A bronchofibroscopy was conducted with a fungal culture, showing growth of Cryptococcus laurentii colonies. Amphotericin B was started thereafter but discontinued three days later in favor of fluconazole 400 mg/d due to worsening renal function. The patient became afebrile after 72 h of treatment with considerable improvement of other comorbidities and was finally discharged with continuing oral antifungal therapy.

Conclusions

Our cases illustrate that cryptococcal disease is an important consideration when treating immunocompromised individuals such as AIDS patients. Life threatening meningitis or meningoencephalitis caused by C. neoformansmay still common in these populations and can vary greatly in clinical presentations, especially with regard to skin lesions. Pulmonary cryptococcosis caused by C. laurentii is rare, but should also be considered in certain contexts. Guidelines for its earlier diagnosis, treatment and prophylaxis are needed.

Catheter-related infection due to Papiliotrema laurentii in an oncologic patient: Case report and systematic review

Background

Papiliotrema laurentii is one of several non-neoformans cryptococci that have rarely been associated with human infection, since it was previously considered saprophyte and thought to be non-pathogenic to humans. Nevertheless, increasing number of reports of human infection have emerged in recent years, mostly in oncologic patients.

Aim

To report a case of a female patient with pyloric obstructive cancer with a catheter-related Papiliotrema laurentii blood stream infection and systematically review the available evidence on P. laurentii infection in humans.

Methods

Retrieval of studies was based on Medical Subject Headings and Health Sciences Descriptors, which were combined using Boolean operators. Searches were run on the electronic databases Scopus, Web of Science, MEDLINE (PubMed), BIREME (Biblioteca Regional de Medicina), LILACS (Latin American and Caribbean Health Sciences Literature), Cochrane Library for Systematic Reviews and Opengray.eu. There was no language or date of publication restrictions. The reference lists of the studies retrieved were searched manually.

Results

The search strategy retrieved 1703 references. In the final analysis, 31 references were included, with the description of 35 cases. Every patient but one had a previous co-morbidity - 48.4 % of patients had a neoplasm. Amphotericin B was the most used treatment and only a single case of resistance to it was reported. Most patients were cured of the infection.

Conclusion

P. laurentii infection in humans is usually associated to neoplasia and multiple co-morbidities, and amphotericin B seems to be a reliable agent for treatment.

Community-acquired Disseminated Exophiala dermatitidis Mycosis with Necrotizing Fasciitis in Chronic Graft-versus-host Disease

We herein report a case of systemic phaeohyphomycosis by Exophiala dermatitidis (E. dermatitidis) with chronic graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation (HSCT). The patient had been taking oral corticosteroids for years to control the GVHD. Yeast-like fungi were identified in a blood culture, so treatment with micafungin (150 mg/day) was begun, with no improvement. The patient passed away on hospital Day 12. A sequence analysis of rRNA revealed the isolate to be E. dermatitidis. This report brings attention to an emerging mycosis of community-acquired Exophiala species infection in the very-late phase after allogenic HSCT in patients with chronic GVHD.