Geotrichum candidum septicemia in a child with hepatoblastoma

Phenotypic and molecular genetics study of Geotrichum candidumLink (1809) and Geotrichum silvicola Pimenta (2005) cultivated on mitis salivarius agar

BACKGROUND

Geotrichum is a genus of fungi found in different habitats throughout the world. Although Geotrichum and its related species have been extensively reclassified and taxonomically revised, it is still the target for many researches.

METHODS AND RESULTS

In this study, phenotypic and molecular genetics comparisons were performed between Geotrichum candidum and Geotrichum silvicola. Mitis Salivarius Agar was used as the growing medium for the phenotypic comparison study, which was carried out at two temperatures (20-25 and 37 °C). For genotypic comparison, we compared the 18 S, ITS, and 28 S sequences of universal DNA barcode regions of both species. Important findings on the new culture media for fungal isolation were revealed by the results. The phenotypic variation between the two species' colonies, including their shapes, sizes, textures and growth rates, were strikingly different. DNA sequences of both species showed that pairwise identities of the species were 99.9% for 18 S, 100% for ITS and 99.6% for 28 S regions.

CONCLUSIONS

Contrary to what is commonly seen, the results showed that 18 S, ITS and 28 S failed to discriminate the species. The first investigation into the performance of Mitis Salivarius Agar as a fungus culture medium is reported in this work, and proved its efficiency. Additionally, this is the first study to compare G. candidum with G. silvicola by means of both phenotypic and genotypic analysis.

Uncovering the Biotechnological Importance of Geotrichum candidum

Fungi make a fundamental contribution to several biotechnological processes, including brewing, winemaking, and the production of enzymes, organic acids, alcohols, antibiotics, and pharmaceuticals. The present review explores the biotechnological importance of the filamentous yeast-like fungus Geotrichum candidum, a ubiquitous species known for its use as a starter in the dairy industry. To uncover G. candidum's biotechnological role, we performed a search for related work through the scientific indexing internet services, Web of Science and Google Scholar. The following query was used: Geotrichum candidum, producing about 6500 scientific papers from 2017 to 2022. From these, approximately 150 that were associated with industrial applications of G. candidum were selected. Our analysis revealed that apart from its role as a starter in the dairy and brewing industries, this species has been administered as a probiotic nutritional supplement in fish, indicating improvements in developmental and immunological parameters. Strains of this species produce a plethora of biotechnologically important enzymes, including cellulases, β-glucanases, xylanases, lipases, proteases, and α-amylases. Moreover, strains that produce antimicrobial compounds and that are capable of bioremediation were identified. The findings of the present review demonstrate the importance of G. candidum for agrifood- and bio-industries and provide further insights into its potential future biotechnological roles.

Invasive Geotrichum klebahnii fungal infection: A case report

Geotrichosis is a world-wide mycosis caused by Geotrichum species. We report a rare case of an invasive cutaneous infection by Geotrichum klebahnii in a female patient with undiagnosed diabetes mellitus. The patient presented with right facial swelling not responding to antibiotics and could not recall trauma to the site of the lesion. Histological examination showed fungal hyphae invading salivary glands and bony tissues, and G. klebahnii was isolated from the culture of biopsy material. Matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry (MS) confirmed the fungal species. Broth microdilution showed low minimum inhibitory concentrations (MICs) for itraconazole, posaconazole, voriconazole and amphotericin B. Treatment with sequential administration of intravenous amphotericin B with voriconazole followed by itraconazole led to the resolution of the lesion.

Consensus guidelines for the diagnosis and management of cryptococcosis and rare yeast infections in the haematology/oncology setting, 2021

Cryptococcosis caused by the Cryptococcus neoformans-Cryptococcus gattii complex is an important opportunistic infection in people with immunodeficiency, including in the haematology/oncology setting. This may manifest clinically as cryptococcal meningitis or pulmonary cryptococcosis, or be detected incidentally by cryptococcal antigenemia, a positive sputum culture or radiological imaging. Non-Candida, non-Cryptococcus spp. rare yeast fungaemia are increasingly common in this population. These consensus guidelines aim to provide clinicians working in the Australian and New Zealand haematology/oncology setting with clear guiding principles and practical recommendations for the management of cryptococcosis, while also highlighting important and emerging rare yeast infections and their recommended management.

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.

Cutaneous geotrichosis due to Geotrichum candidum in a burn patient

Geotrichum candidum is a saprophytic yeast known to colonize the human skin, respiratory tract and gastrointestinal tract. It can cause local or disseminated disease (geotrichosis), mainly in the immunocompromised host. Trauma, indwelling catheter use, prolonged broad-spectrum antibiotic treatment and critical illness have also been implicated as risk factors. Here we report the first case, to our knowledge, of cutaneous G. candidum infection in a burn patient. The isolate had a high amphotericin B minimum inhibitory concentration (MIC) and the patient experienced concomitant Candidaorthopsilosis fungaemia, and so was treated with a combination of voriconazole and micafungin. This case highlights the importance of source control, rapid identification of G. candidum infection and MIC determination to guide antifungal therapy, which typically consists of amphotericin B with or without flucytosine or voriconazole alone. Clinicians should be aware of geotrichosis as a clinical entity in burn patients as well as in the immunocompromised. Antifungal resistance and breakthrough disease are an ongoing concern due to the increasing number of immunocompromised at-risk patients and the use of routine mould prophylaxis.

Oral Fungal Infections: Diagnosis and Management

Oral and maxillofacial fungal infections can appear in high-risk patients, including those immunocompromised. This article explores common oral manifestations of fungal infections in the oral cavity as primary lesions or as a result of disseminated disease. By far the most common oral fungal infection experienced in dentistry is oral candidiasis, which is reviewed in depth from simple oral infections to invasive candidiasis. The review aids the dental practitioner in understanding the full scope of Candida infections and other fungal infections. In addition to candidiasis, various other fungal infections are reviewed, including mucormycosis, aspergillosis, blastomycosis, histoplasmosis, cryptococcosis, and coccidioidomycosis.

Post operative fungal endopthalmitis due to Geotrichum candidum

Geotrichum species have been rarely reported as the cause of sepsis, disseminated infection in immunosuppressed patients. The patient we describe developed indolent endophthalmitis four months after her routine right eye cataract surgery. The intraoperative sample from right vitreous fluid grew Geotrichum candidum. The patient underwent vitrectomy, artificial lens explantation and intravitreal injection of amphotericin B followed by oral voriconazole. Despite these interventions, she underwent enucleation. This is the first published case of Geotrichum candidum endophthalmitis.

Immunodetection of fungal and oomycete pathogens: established and emerging threats to human health, animal welfare and global food security

Filamentous fungi (moulds), yeast-like fungi, and oomycetes cause life-threatening infections of humans and animals and are a major constraint to global food security, constituting a significant economic burden to both agriculture and medicine. As well as causing localized or systemic infections, certain species are potent producers of allergens and toxins that exacerbate respiratory diseases or cause cancer and organ damage. We review the pathogenic and toxigenic organisms that are etiologic agents of both animal and plant diseases or that have recently emerged as serious pathogens of immunocompromised individuals. The use of hybridoma and phage display technologies and their success in generating monoclonal antibodies for the detection and control of fungal and oomycete pathogens are explored. Monoclonal antibodies hold enormous potential for the development of rapid and specific tests for the diagnosis of human mycoses, however, unlike plant pathology, their use in medical mycology remains to be fully exploited.

Tonsillitis in a weaner pig associated with Geotrichum candidum

Geotrichum candidum was cultured from the tonsils of a free-ranging weaner pig that was presented with lethargy and inappetence. Histopathology indicated pyogranulomatous tonsillitis with intralesional fungal hyphae and arthrospores. Geotrichosis is a rare, opportunistic mycosis of immunocompromised hosts, usually human beings.

Invasive cutaneous infection withGeotrichum candidum– sequential treatment with amphotericin B and voriconazole

A rare case of an invasive cutaneous infection by Geotrichum candidum in an 80-year-old male patient with diabetes mellitus is reported. The primary site of infection manifested after trauma as an ulcerative lesion on the distal phalanx of the midfinger and extended throughout the right hand. Histological examination showed fungal invasion in the deep dermis without vascular involvement and G. candidum was grown in cultures from the biopsy material. Angiography revealed severe obstructive disease of the right brachial artery and its branches. Treatment, after susceptibility testing of the isolated strain, consisted of sequential administration of intravenous liposomal amphotericin B with oral voriconazole followed by liposomal amphotericin B, resulting in substantial improvement of the infection.