Mixed Fungal Biofilms: From Mycobiota to Devices, a New Challenge on Clinical Practice

Abstract

Most current protocols for the diagnosis of fungal infections are based on culture-dependent methods that allow the evaluation of fungal morphology and the identification of the etiologic agent of mycosis. Most current protocols for the diagnosis of fungal infections are based on culture-dependent methods that enable the examination of the fungi for further identification of the etiological agent of the mycosis. The isolation of fungi from pure cultures is typically recommended, as when more than one species is identified, the second agent is considered a contaminant. Fungi mostly survive in highly organized communities that provoke changes in phenotypic profile, increase resistance to antifungals and environmental stresses, and facilitate evasion from the immune system. Mixed fungal biofilms (MFB) harbor more than one fungal species, wherein exchange can occur that potentialize the effects of these virulence factors. However, little is known about MFB and their role in infectious processes, particularly in terms of how each species may synergistically contribute to the pathogenesis. Here, we review fungi present in MFB that are commensals of the human body, forming the mycobiota, and how their participation in MFB affects the maintenance of homeostasis. In addition, we discuss how MFB are formed on both biotic and abiotic surfaces, thus being a significant reservoir of microorganisms that have already been associated in infectious processes of high morbidity and mortality.

Inhibitory effect of lactobacilli supernatants on biofilm and filamentation of Candida albicans, Candida tropicalis, and Candida parapsilosis

“…Formation of Candida biofilm on abiotic surfaces of indwelling medical devices, such as dentures, endotracheal tubes, intragastric balloons, urinary catheters, and intravascular catheters, can lead to device failure and Candida infections ( Costa et al, 2022 ). A meta-analysis of 31 studies revealed that the rate of biofilm formation among Candida strains isolated from blood culture of hospitalized patients varied from 16 to 100% with a pooled rate of 80.0% ( Atiencia-Carrera et al, 2022 ).…”

Using nanopore sequencing to identify fungi from clinical samples with high phylogenetic resolution

“…Diagnostics of fungal infections have focused on a limited range of pathogens commonly encountered in clinical settings, where a single strain is thought to be responsible for the disease. Recent studies suggest the existence of mixed fungal colonization in the human body, and the resulting infection can lead to more severe symptoms than those caused by a single species 31 . With the continuing expansion of the number and diversity of fungal species potentially associated with human diseases, there has been an increasing demand for rapid and reliable means for analyzing the human fungal microbiota across broad taxonomic scales 32 .…”

Study on the microbial diversity of ear canal secretions from patients with otomycosis

“…Clinically, determining what kind of opportunistic fungal infection is involved and whether bacteria are involved are highly important for the early diagnosis and treatment of otomycosis. At present, opportunistic fungi are mainly identified clinically by isolation, culture, and microscopic examination based on fungal morphology ( 19 ). However, the above methods have several limitations, such as equipment conditions, personnel level, and staining methods ( 20 ).…”