Update on antifungal treatment of invasive Candida and Aspergillus infections. Derzeitiger Kenntnisstand in der antimykotischen Behandlung invasiver Candida- und Aspergillus-Infektionen

Invasive maxillary aspergillosis in a patient with systemic lupus erythematosus: Case report

Introduction

Invasive aspergillosis (IA) is a fungal infection caused by Aspergillus species (spp.). Aspergillosis is the most common source of opportunistic fungal infection in humans. IA can cause serious complications related to high morbidity and mortality in immunocompromised patients.

Presentation of case

We report a case of a 22-year-old female with a chief complaint of having a hole in the roof of her mouth. She was diagnosed with SLE in 2009. She had been consuming oral methylprednisolone ever since. In 2018, she experienced worsened symptoms and was hospitalized. She experienced swelling and bleeding of her gums and some of her teeth becoming loose and falling out, and then developing a hole in the roof of her mouth. Subsequently, she was treated with oral cyclophosphamide, oral mycophenolate sodium, and oral fluconazole. She was asked to stop taking oral methylprednisolone. In 2019, the palate biopsy was performed and showed Aspergillus spp. invading the palate. Afterward, the patient was referred to our clinic for defect closure. The patient was operated on for debridement and reconstruction of the defect. There was no recurrence of the defect or complications observed in the follow-up. The patient was satisfied with the surgical results.

Discussion

IA is a destructive and potentially harmful opportunistic fungal infection and treatments with surgical interventions should be well-thought-out in immunocompromised patients.

Conclusion

The management of IA are controlling any underlying diseases and surgical debridement or necrotomy. Generally, antifungal therapy and prompt surgical intervention are successful in managing invasive aspergillosis.

Diverse transposable element landscapes in pathogenic and nonpathogenic yeast models: the value of a comparative perspective

Genomics and other large-scale analyses have drawn increasing attention to the potential impacts of transposable elements (TEs) on their host genomes. However, it remains challenging to transition from identifying potential roles to clearly demonstrating the level of impact TEs have on genome evolution and possible functions that they contribute to their host organisms. I summarize TE content and distribution in four well-characterized yeast model systems in this review: the pathogens Candida albicans and Cryptococcus neoformans, and the nonpathogenic species Saccharomyces cerevisiae and Schizosaccharomyces pombe. I compare and contrast their TE landscapes to their lifecycles, genomic features, as well as the presence and nature of RNA interference pathways in each species to highlight the valuable diversity represented by these models for functional studies of TEs. I then review the regulation and impacts of the Ty1 and Ty3 retrotransposons from Saccharomyces cerevisiae and Tf1 and Tf2 retrotransposons from Schizosaccharomyces pombe to emphasize parallels and distinctions between these well-studied elements. I propose that further characterization of TEs in the pathogenic yeasts would enable this set of four yeast species to become an excellent set of models for comparative functional studies to address outstanding questions about TE-host relationships.

Viral, bacterial, and fungal infections of the oral mucosa: Types, incidence, predisposing factors, diagnostic algorithms, and management

For millions of years, microbiota residing within us, including those in the oral cavity, coexisted in a harmonious symbiotic fashion that provided a quintessential foundation for human health. It is now clear that disruption of such a healthy relationship leading to microbial dysbiosis causes a wide array of infections, ranging from localized, mild, superficial infections to deep, disseminated life-threatening diseases. With recent advances in research, diagnostics, and improved surveillance we are witnessing an array of emerging and re-emerging oral infections and orofacial manifestations of systemic infections. Orofacial infections may cause significant discomfort to the patients and unnecessary economic burden. Thus, the early recognition of such infections is paramount for holistic patient management, and oral clinicians have a critical role in recognizing, diagnosing, managing, and preventing either new or old orofacial infections. This paper aims to provide an update on current understanding of well-established and emerging viral, bacterial, and fungal infections manifesting in the human oral cavity.

Uncommon opportunistic fungal infections of oral cavity: A review

The majority of opportunistic oral mucosal fungal infections are due to Candida albicans and Aspergillus fumigatus species. Mucor and Cryptococcus also have a major role in causing oral infections, whereas Geotrichum, Fusarium, Rhodotorula, Saccharomyces and Penicillium marneffei are uncommon pathogens in the oral cavity. The broad spectrum of clinical presentation includes pseudo-membranes, abscesses, ulcers, pustules and extensive tissue necrosis involving bone. This review discusses various uncommon opportunistic fungal infections affecting the oral cavity including their morphology, clinical features and diagnostic methods.

In vitro susceptibility of Candida species to four antifungal agents assessed by the reference broth microdilution method

This study was performed to determine the distribution of Candida species isolated from the blood cultures of the patients hospitalized in our hospital and to investigate their antifungal susceptibility. Candida strains were identified at species level by using classical methods and API ID 32C (bioMerieux, France) identification kits. The susceptibility of the strains to amphotericin B, fluconazole, voriconazole, and caspofungin was evaluated by using the reference broth microdilution method in document M27-A3 of the Clinical and Laboratory Standards Institute. Of the 111 Candida strains isolated, 47.7% were identified as C. albicans and 52.3% as non-albicans Candida strains. The MIC ranges were 0.03–1 μg/mL for amphotericin B, 0.125–≥64 μg/mL for fluconazole, 0.03–16 μg/mL for voriconazole, and 0.015–0.25 μg/mL for caspofungin. All Candida strains were susceptible to amphotericin B and caspofungin. 10.8% isolates were resistant to fluconazole and 8.1% isolates were dose-dependent susceptible. While 0.9% isolate was resistant to voriconazole, 0.9% isolate was dose-dependent susceptible. In our study, C. albicans and C. parapsilosis were the most frequently encountered agents of candidemia and it was detected that voriconazole with a low resistance rate might also be used with confidence in the treatment of infections occurring with these agents, primarily besides amphotericin B and caspofungin.

Clinical Efficacy and Tolerability of Caspofungin in a Renal Transplant Patient withAspergillus flavusLung Infection: Case Report

Organ transplant recipients are at increased risk for severe invasive aspergillosis, and amphotericin deoxycholate has been the standard treatment for many years. Currently, however, lipid formulations are preferred due to their few side effects. Also, a number of new antifungal drugs have been developed including new azoles and echinocandins. Caspofungin is the first of the echinocandin derivatives patented to treat patients with invasive aspergillosis who are refractory or intolerant to other therapies. A renal transplant patient on immunosuppressive treatment with chronic hepatitis B virus infection was admitted with fever, hemophthisis and lung consolidation, diagnosed to be probably caused by Aspergillus flavus. The patient developed cholestatic hepatitis most likely related to itraconazole. Clinical failure and in vitro itraconazole resistance of the isolate was also documented while the patient was receiving itraconazole at a reduced dosage. Caspofungin was administered once a day as ambulatory treatment and was well tolerated. Clinical improvement was observed after 6 weeks of treatment and no hepatic toxicity was documented. Caspofungin seems to be a potentially useful antifungal agent in renal transplant patients with invasive aspergillosis. Further evaluation of the efficacy of caspofungin is needed.

Antimicrobial and antiprotozoal activities of secondary metabolites from the fungus Eurotium repens

In this study, we examined in vitro antibacterial, antifungal, antimalarial, and antileishmanial activities of secondary metabolites (1-8) isolated from the fungus Eurotium repens. All compounds showed mild to moderate antibacterial or antifungal or both activities except 7. The activity of compound 6 was the best of the group tested. The in vitro antimalarial evaluation of these compounds revealed that compounds 1-3, 5, and 6 showed antimalarial activities against both chloroquine-sensitive and chloroquine-resistant strains of Plasmodium falciparum with IC(50) values in the range of 1.1-3.0 μg/ml without showing any cytotoxicity to the mammalian cells. Compound 5 displayed the highest antimalarial activity. Antileishmanial activity against Leishmania donovani promastigotes was observed for compounds 1-6 with IC(50) values ranging from 6.2 to 23 μg/ml. Antileishmanial activity of compounds 5 and 6 (IC(50) values of 7.5 and 6.2 μg/ml, respectively) was more potent than 1-4 (IC(50) values ranging from 19-23 μg/ml). Compounds 7 and 8 did not show any antiprotozoal effect. Preliminary structure and activity relationship studies indicated that antibacterial, antifungal, antimalarial, and antileishmanial activities associated with phenol derivates (1-6) seem to be dependent on the number of double bonds in the side chain, which would be important for lead optimization in the future.

Resveratrol and its antifungal activity against Candida species

Resveratrol is a natural stilbene synthesised by plants. This compound has been shown to inhibit the growth of Candida albicans TIMM 1768 efficiently. Till date, no information is available for other Candida species. The evaluation of the antimicrobial activity of resveratrol was analysed by the inhibition of the growth and metabolism assays. Our data indicate that resveratrol is not effective against Candida albicans and non-C. albicans species (C. dubliniensis, C. glabrata, C. tropicalis, C. parapsilosis and C. krusei) in vitro. The potential candidacidal activity could not be confirmed.

Invasive oral aspergillosis in a patient with acute myeloid leukaemia

Aspergillosis (a fungal infection by an organism of the Aspergillus species) of the oral cavity is an uncommon condition which most frequently occurs in immunocompromised patients, such as those with haematological malignancies. In such patients, prolonged neutropenia secondary to chemotherapeutic agents enables the spread of invasive aspergillosis, which is unaffected by anatomical barriers. Early detection and treatment of the condition is essential to avoid more serious complications, such as disseminated infection, which results in increased morbidity and mortality. This case report describes a patient with acute myeloid leukaemia who developed localized invasive Aspergillus flavus of the palate. High-dose antifungal therapy was instituted along with surgical removal of the involved tissues. Aspergillosis of the palate was successfully eradicated with no long-term ill effects from the treatment. Management of invasive aspergillosis includes early aggressive antifungal medication combined with surgical removal of the involved tissues.

Itraconazole-loaded poly(lactic-co-glycolic) acid nanoparticles for improved antifungal activity

Aims: Poly(lactic-co-glycolic) acid (PLGA) nanoparticles containing the hydrophobic antifungal itraconazole (ITZ) were developed to address the need for more effective means of treating fungal infections. Materials & methods: PLGA–ITZ nanoparticles were synthesized using an oil-in-water emulsion evaporation method. Nanoparticle morphology (studied by transmission electron microscopy), size zeta potential (dynamic light scattering), encapsulation efficiency (UV–visible spectroscopy), release profile and antifungal activity were characterized. Results: PLGA–ITZ nanoparticles (of 220 nm in diameter) completely inhibited Aspergillus flavus growth over 11 days at 0.03 mg/ml ITZ; a similar effect was achieved at ×100 ITZ concentrations (3 mg/ml) in emulsified form. The ITZ in water formulation had the least antifungal effect, inhibiting growth for only 2 days at 3 mg/ml ITZ. Conclusion: This system is envisioned to increase bioavailability of ITZ by improving aqueous dispersibility and increasing antifungal penetration, thereby increasing antifungal activity of the entrapped drug.

The effects of caspofungin and voriconazole in an experimental fungal infection of the ear due to Aspergillus

The purpose of the study was to evaluate the effectiveness of caspofungin and voriconazole in the treatment of experimental Aspergillus otitis media in an experimental rabbit model. A total of 30 New Zealand white rabbits were divided into four treatment groups and one control group. The rabbits were immunosuppressed by cyclophosphamide and triamcinolone acetonide. The right ear of each rabbit was infected by an injection of the inoculum of 0.1 ml (8.6 x 103 CFU/0.1 ml) of Aspergillus fumigatus into the middle ear cavity. At 72 h after the inoculation, amphotericin B 1 mg/kg per day (n = 6), itraconazole 10 mg/kg per day (n = 6), voriconazole 10 mg/kg per day (n = 6) and caspofungin 5 mg/kg per day (n = 6) were injected to each treatment group. No antifungal drug was administered to the control group (n = 6). Clinical and histopathological examination scores and microbiological analysis of middle ear mucosa were compared.There was statistically significant difference in the clinical scores, histopathological scores, and mean CFU/g between the treatment and control groups (P < 0.05). There was no statistically significant difference among the treatment groups in the clinical and histopathological scores, whereas there was statistically significant difference in the mean CFU/g (P < 0.05). The mean CFU/g of amphotericin B and caspofungin groups were similar and both were lower than the itraconazole and voriconazole groups. Also, the mean CFU/g of voriconazole group was lower than the itraconazole group (P < 0.05). Caspofungin and voriconazole were demonstrated at least as effective as amphotericin B and itraconazole. We suggest that caspofungin and voriconazole may be considered for the treatment of fungal infection of the ear.

Efficacies of caspofungin and a combination of caspofungin and meropenem in the treatment of murine disseminated candidiasis

Disseminated candidiasis is relatively common in immunocompromised patients. The treatment protocol of these patients usually includes broad-spectrum antibiotics and also emprical antifungals initiated due to unresponsiveness to antibiotics. In this study the efficacies of caspofungin and meropenem - separately and together - in mice with disseminated candidiasis were studied. Immunocompetent mice were infected intravenously with 2x10(6) CFU of Candida albicans. At 24 h postinfection, intraperitoneal therapy was initiated and was continued for 7 days. Therapy groups included those given caspofungin (0.5, 1.25, 5 mg/kg/day), meropenem (20 mg/kg/day), and a combination of the two drugs. The outcome of therapy was evaluated by kidney tissue burden studies and histologic examination. In vitro, drug susceptibilities were tested by checkerboard analysis. Kidney CFU counts showed that mice that had received both drugs had lower residual burdens. Caspofungin was effective at doses of 0.5, 1.25, 5 mg/kg compared to infected untreated controls. In vitro, MICs of caspofungin and meropenem were <0.075 micro g/ml and >64 micro g/ml, respectively. Synergism was observed with the combination. Histopathology showed that the degree of inflammation was 25% less and tubular necrosis was more restricted in combined therapy than monotherapy. The results indicate that concurrent caspofungin and meropenem therapy may be beneficial.

Invasive esophageal aspergillosis associated with acute myelogenous leukemia: successful therapy with combination caspofungin and liposomal amphotericin B

Aspergillosis is one of the most common invasive fungal infections in patients with leukemia. In this patient group, this form of Aspergillus infection is a life-threatening condition with a mortality of 50-100%. The lungs are most often affected, but the esophagus can also be involved.The authors report the case of a child with leukemia who developed invasive esophageal aspergillosis. The condition was diagnosed by microscopic examination of endoscopic biopsy specimens. The patient was already receiving empirical liposomal amphotericin B when the diagnosis was made, so a second antifungal (caspofungin) was added to the regimen. This combination was successful. This case to demonstrates a case of successful treatment of invasive esophageal aspergillosis using combination therapy of liposomal amphotericin B and caspofungin.

Application of fluorescent probes to study structural changes in Aspergillus fumigatus exposed to amphotericin B, itraconazole, and voriconazole

The broad objective of this study was to document patterns of structural changes following antifungal treatment, and to determine any relationship with minimum inhibitory concentration (MIC) of an antifungal. Three clinical isolates of Aspergillus fumigatus, with high, intermediate, and low amphotericin B (AB), itraconazole (IZ), and voriconazole (VZ) MICs were studied in 24-well plates with cover slips. The fluorescent probes used were Calcofluor White (cell wall), propidium iodide (nucleus), and MitoTracker Green FM (mitochondria). Fluorescent microscopy as early as 3-h after exposure revealed that AB treated hyphae had intact cell wall with deformed mitochondria and nuclei while IZ and VZ treated hyphae revealed no intact cell wall, and deformation of mitochondria and nuclei. At 48 h, AB treated cells revealed rupture of hyphae and disintegration of mitochondria, and nuclei, IZ treated hyphae were swollen with disintegration of mitochondria, and nuclei while VZ treated hyphae showed rupture and disintegration of mitochondria and nuclei. The structural changes for the three strains studied were similar in fluorescent microscopy as long as the incubation time and their respective MICs were used. Thus, AB, IZ, and VZ induced gross organelle defects in A. fumigatus nuclei, mitochondria, and cell wall, which were consistent with respective MICs of antifungals used.

Developments in the treatment of candidiasis: more choices and new challenges

The incidence of oesophageal candidiasis, candidaemia and disseminated candidiasis has increased dramatically. In addition to the amphotericin B formulations and fluconazole, the echinocandins anidulafungin, caspofungin and micafungin and the newer triazoles posaconazole and voriconazole are in the last stages of development and are becoming available for the management of candidiasis. This review presents these new agents and addresses their role in the treatment of candidiasis. All new antifungal agents exhibit potent activity against Candida spp. and echinocandins are fungicidal against most Candida spp. but appear to be less potent against certain species, such as Candida parapsilosis and C. guilliermondii. Systemic antifungal therapy can now be individualised based on the severity of the infection, comorbid conditions and the Candida spp. causing the infection. Studies are needed to investigate the possible development of resistance and the efficacy of these antifungal agents against the more resistant Candida spp.

Successful caspofungin treatment of multidrug resistant Candida parapsilosis septicaemia in an extremely low birth weight neonate

Candida septicaemia with multidrug resistance is an uncommon event in preterm neonates. We present an extremely low birth weight infant (gestational age of 27 weeks, birth weight of 980 g) who developed congenital Candida parapsilosis septicaemia. Because the fungus was resistant both to amphotericin B and fluconazole, caspofungin was chosen for therapy. The fungus was successfully eradicated without any clinical or laboratory adverse effects.

Aspergillus fumigatus tricuspid native valve endocarditis in a non-intravenous drug user

Invasive aspergillosis is an emerging infection mainly affecting immunocompromised patients. This report details a case of Aspergillus fumigatus tricuspid native valve endocarditis complicated by recurrent septic pulmonary emboli in a young, non-intravenous drug user. He was treated by surgical resection of the posterior leaflet of the tricuspid valve and the vegetations, as well as by valvuloplasty, which was followed by a combination of liposomal amphotericin B and voriconazole as acute-phase therapy and voriconazole alone as suppression therapy.

[Diagnostics and therapy for invasive fungal infections in an intensive care unit]

Invasive fungal infections are associated with a high mortality and have been increasing in incidence over the last few decades. Candidemia and, less commonly, invasive pulmonary aspergillosis are the most relevant fungal infections in critical care medicine. Risk factors for systemic Candida infections are the use of broad-spectrum antibiotics, a prolonged stay in an intensive care unit and gastrointestinal injury or surgery. Invasive aspergillosis usually occurs in immunocompromised patients. The diagnosis of invasive fungal infections remains challenging. The therapeutic spectrum includes fluconazol, conventional and liposomal amphotericin B, and the recently introduced agents caspofungin and voriconazol. For rational and cost-effective use, the clinician requires precise knowledge of the indications and limitations of these agents. This review focuses on the diagnostic and therapeutic options in severe Candida infections and invasive aspergillosis.

Fungal arthritis and osteomyelitis

Fungal arthritis and osteomyelitis are uncommon diseases and generally present in an indolent fashion. The incidence of fungal bone and joint dis-ease is increasing with an increase in the prevalence of factors predisposing to invasive fungal disease, such as the use of central venous catheters, broad spectrum antibiotics, immunosuppression, and abdominal surgery. Definitive diagnosis relies on bone or synovial culture or biopsy. Successful management has traditionally consisted of amphotericin B in combination with surgical debridement. Given the rarity of this disease, treatment is not well defined, but reports of success with the use of azole antifungal agents, including itraconazole, fluconazole, voriconazole, and posaconazole, are promising.

Fatal Scopulariopsis Infection in a Lung Transplant Recipient: A Case Report

A case of a fatal Scopulariopsis infection is reported in a 63-year-old lung transplantation patient with a 7-week history of dyspnea that presented initially with pericardial and pleural fluid. Because of a respiratory arrest, the patient was intubated and received positive pressure ventilation. Later, obstructive shock developed due to a pericardial tamponade requiring pericardectomy and then urgent extracorporal membrane oxygenation. The working hypothesis was of disseminated cytomegalovirus infection because cultures from bronchoalveolar lavage and transbronchial biopsy specimens were positive. The pericardial biopsy specimen showed fungal hyphae. After the patient died from the infection, the fungus was identified as Scopulariopsis acremonium. This case report describes the first case, to our knowledge, of an insidious Scopulariopsis acremonium infection in an immunocompromised lung transplant patient, underscoring the importance of a direct, invasive approach and early treatment with anti-fungal therapy in immunocompromised patients.

Ovarian cancer complicated by invasive pulmonary aspergillus

BACKGROUND

Invasive aspergillus is a rarely reported infection in patients with solid tumors.

CASE

A 59-year-old woman developed invasive pulmonary aspergillus after surgical debulking of an advanced ovarian adenocarcinoma and initiation of adjuvant combination chemotherapy.

CONCLUSION

Invasive pulmonary aspergillus is rarely diagnosed in patients with solid tumors such as ovarian cancer. Risk factors for development of the disease can include neutropenia, immunosuppression and chronic steroid use. Successful treatment of the infection relies upon prompt diagnosis and utilization of effective antifungal medications for a prolonged period of time.

[Antimycotic drugs under continuous renal replacement therapy]

In critically ill patients with acute renal failure and continuous renal replacement therapy (CRRT), the elimination of antimycotic agents is influenced by many factors; these include not only the nature and dose of the renal replacement therapy but also the properties of the medicine. High protein binding, a high molecular weight and little or no renal elimination even in subjects with normal renal function suggest that a substance is not eliminated by CRRT. This is the case with amphotericin B, caspofungin, itraconazole and voriconazole, but not with fluconazole. In the case of fluconazole, an increase in dose than that used in patients with normal renal function may be required according to the nature and dose of CRRT, because the clearance of fluconazole can be substantially higher under CRRT than in subjects with normal renal function. Daily doses of 800 mg or more may be necessary. As a result of the diverse influences on elimination in patients receiving CRRT, the determination of fluconazole through concentrations cannot be dispensed with, in order to avoid underdosing and a failure of the antimycotic therapy.

The structure of the Candida albicans Ess1 prolyl isomerase reveals a well-ordered linker that restricts domain mobility

Ess1 is a peptidyl-prolyl cis/trans isomerase (PPIase) that binds to the carboxy-terminal domain (CTD) of RNA polymerase II. Ess1 is thought to function by inducing conformational changes in the CTD that control the assembly of cofactor complexes on the transcription unit. Ess1 (also called Pin1) is highly conserved throughout the eukaryotic kingdom and is required for growth in some species, including the human fungal pathogen Candida albicans. Here we report the crystal structure of the C. albicansEss1 protein, determined at 1.6 A resolution. The structure reveals two domains, the WW and the isomerase domain, that have conformations essentially identical to those of human Pin1. However, the linker region that joins the two domains is quite different. In human Pin1, this linker is short and flexible, and part of it is unstructured. In contrast, the fungal Ess1 linker is highly ordered and contains a long alpha-helix. This structure results in a rigid juxtaposition of the WW and isomerase domains, in an orientation that is distinct from that observed in Pin1, and that eliminates a hydrophobic pocket between the domains that was implicated as the main substrate recognition site. These differences suggest distinct modes of interaction with long substrate molecules, such as the CTD of RNA polymerase II. We also show that C. albicans ess1(-)() mutants are attenuated for in vivo survival in mice. Together, these results suggest that CaEss1 might constitute a useful antifungal drug target, and that structural differences between the fungal and human enzymes could be exploited for drug design.

Bad bugs need drugs: an update on the development pipeline from the Antimicrobial Availability Task Force of the Infectious Diseases Society of America

The Antimicrobial Availability Task Force (AATF) of the Infectious Diseases Society of America (IDSA) has viewed with concern the decreasing investment by major pharmaceutical companies in antimicrobial research and development. Although smaller companies are stepping forward to address this gap, their success is uncertain. The IDSA proposed legislative and other federal solutions to this emerging public health problem in its July 2004 policy report "Bad Bugs, No Drugs: As Antibiotic R&D Stagnates, a Public Health Crisis Brews." At this time, the legislative response cannot be predicted. To emphasize further the urgency of the problem for the benefit of legislators and policy makers and to capture the ongoing frustration our clinician colleagues experience in their frequent return to an inadequate medicine cabinet, the AATF has prepared this review to highlight pathogens that are frequently resistant to licensed antimicrobials and for which few, if any, potentially effective drugs are identifiable in the late-stage development pipeline.