The impact of the Fungus-Host-Microbiota interplay uponCandida albicansinfections: current knowledge and new perspectives

Abstract

Candida albicans is a major fungal pathogen of humans. It exists as a commensal in the oral cavity, gut or genital tract of most individuals, constrained by the local microbiota, epithelial barriers and immune defences. Their perturbation can lead to fungal outgrowth and the development of mucosal infections such as oropharyngeal or vulvovaginal candidiasis, and patients with compromised immunity are susceptible to life-threatening systemic infections. The importance of the interplay between fungus, host and microbiota in driving the transition from C. albicans commensalism to pathogenicity is widely appreciated. However, the complexity of these interactions, and the significant impact of fungal, host and microbiota variability upon disease severity and outcome, are less well understood. Therefore, we summarise the features of the fungus that promote infection, and how genetic variation between clinical isolates influences pathogenicity. We discuss antifungal immunity, how this differs between mucosae, and how individual variation influences a person's susceptibility to infection. Also, we describe factors that influence the composition of gut, oral and vaginal microbiotas, and how these affect fungal colonisation and antifungal immunity. We argue that a detailed understanding of these variables, which underlie fungal-host-microbiota interactions, will present opportunities for directed antifungal therapies that benefit vulnerable patients.

Crossing Kingdoms: How the Mycobiota and Fungal-Bacterial Interactions Impact Host Health and Disease

“…Fungi not only are the causative agents of disease but also can be isolated from mammals in the absence of disease ( 11 , 15 , 24 – 26 ). C. albicans , for example, can frequently be isolated as a commensal of the oral cavity, vagina, or gut of healthy individuals and only causes infections if the host immune system is compromised or the local microbiota is disturbed ( 22 , 23 ). However, a culture-dependent approach has a high likelihood to yield an incomplete picture of the total fungal diversity ( 11 , 12 ).…”

The cross-kingdom interaction between Helicobacter pylori and Candida albicans

“…Candida albicans, a dimorphic fungus, is one of the most common fungi in the human body [5]. It was noteworthy that C. albicans and H. pylori were abundant in certain human niches, such as the root canal necrotic pulp, stomach, duodenum, and vagina [6], suggesting that C. albicans may interact with H. pylori to promote the growth, spread, and infection of H. pylori in some nonadaptive condition, such as the oral cavity and vagina.…”

“…Candida albicans , a dimorphic fungus, is one of the most common fungi in the human body [ 5 ]. It was noteworthy that C .…”

“…The fecaloral and the oral-oral routes are considered as the main transmission routes of H. pylori [3]. Nevertheless, only H. pylori genes have been detected in saliva and dental plaques, but culturable H. pylori has not been isolated yet in large quantities [4], indicating that there may be some new strategies of H. pylori to implement its transmission through oral cavity.Candida albicans, a dimorphic fungus, is one of the most common fungi in the human body [5]. It was noteworthy that C. albicans and H. pylori were abundant in certain human niches, such as the root canal necrotic pulp, stomach, duodenum, and vagina [6], suggesting that C. albicans may interact with H. pylori to promote the growth, spread, and infection of H. pylori in some nonadaptive condition, such as the oral cavity and vagina.…”

Hyperexpression of CDRs and HWP1 genes negatively impacts on Candida albicans virulence

“…Nevertheless, C. albicans is also a commensal organism present in more than 60% of healthy individuals, being part of the normal human microbiome, localized in the gastrointestinal tract, over the skin, in the oral cavity and in other mucosal surfaces [2,3]. Transition from commensalism towards a systemic infection requires an increased colonization, generally associated with a local or general failure in host defences [4]. Invasive colonization depends upon the conversion of the yeast to the hyphal form, morphologies that C. albicans can assume during its life cycle responding to different environmental conditions [3].…”