Oral mycobiome identification in atopic dermatitis, leukemia, and HIV patients – a systematic review

Abstract

Introduction: Oral mycobiome profiling is important to understand host-pathogen interactions that occur in various diseases. Invasive fungal infections are particularly relevant for patients who have received chemotherapy and for those who have HIV infection. In addition, changes in fungal microbiota are associated with the worsening of chronic conditions like atopic dermatitis (AD). This work aims, through a systematic review, to analyze the methods used in previous studies to identify oral fungi and their most frequent species in patients with the following conditions: HIV infection, leukemia, and atopic dermatitis. Methods: A literature search was performed on several different databases. Inclusion criteria were: written in English or Portuguese; published between September 2009 and September 2019; analyzed oral fungi of HIV-infected, leukemia, or AD patients. Results: 21 studies were included and the most identified species was Candida. The predominant methods of identification were morphological (13/21) and sugar fermentation and assimilation tests (11/21). Polymerase chain reaction (PCR) was the most used molecular method (8/21) followed by sequencing techniques (3/21). Conclusions: Although morphological and biochemical tests are still used, they are associated with high-throughput sequencing techniques, due to their accuracy and time saving for profiling the predominant species in oral mycobiome.

Dysbiosis of skin mycobiome in atopic dermatitis

“…Candida species are present as part of the normal flora on the skin, and are common pathogenic yeasts causing mucocutaneous infections 32 . In previous culture‐based studies, higher frequencies of colonisation by C. albicans were found in the oral cavity and faeces of AD patients than in healthy controls 41–43 . In our review, the relative abundance of Candida did not significantly changed in AD lesions; however, some Candida species were only present in AD patients but not in healthy skin 14 .…”

“…C. albicans could also induce a delayed‐type hypersensitivity response on the skin by inducing the release of T cell co‐stimulatory molecules such as CD 207, CD 80 and CD86 46 . In evaluation of C. albicans ‐specific IgG levels, significantly lower levels of the yeast‐specific IgG were detected in AD patients, indicating the role of humoral immune response to Candida in the pathogenesis of AD 42 …”

Alterations in the oral microbiome in HIV infection: causes, effects and potential interventions

“…In addition, many studies have shown increased Candida colonization in HIV infection. [1,35,69,70] These studies support that HIV infection can significantly change the host oral microbiota. However, the effects of an altered oral microbiome on HIV-associated diseases remain to be shown.…”

“…[31,33,34] In addition to bacterial communities, different fungi are also widely colonized in the human oral cavity. [35] It is known that in elderly and immunocompromised individuals, oral commensal fungi can also serve as opportunistic pathogens. Ghannoum et al [36] used internal transcribed spacer (ITS) sequencing to characterize the oral mycobiome in healthy individuals.…”

HIV-related non-Hodgkin lymphomas affecting the oral cavity: a clinicopathologic study of 11 cases

“…The human immunodeficiency virus (HIV) was initially identified in the 1980s in five young men affected by Pneumocystis carinii pneumonia and other opportunistic infections ( 1 ). HIV infection triggers an important immunosuppression condition by disrupting CD4+ T lymphocytes function, leading to a higher risk of developing opportunistic diseases ( 2 , 3 ), especially when CD4+ T cell count falls below than 200 cells/mm3, when the diagnosis of Acquired Immunodeficiency Syndrome (AIDS) is established ( 3 , 4 ).…”