Dermatophyte infections are the most common fungal infections in humans; among them, tinea capitis (TC) – the most contagious fungal infection – is caused by anthropophilic, zoophilic and geophilic dermatophytes. The purpose of this systematic review was to determine the different aetiological variants involved in TC and the overall epidemiology of the causes of this infection in the last two decades. We searched the MEDLINE (PubMed) and Embase databases for articles published from July 2000 to August 2019 using the following search terms: ‘Tinea capitis’, ‘Africa’, ‘America’, ‘Asia’, ‘Europe’, ‘Oceania’, and the names of the countries on each continent. The flow of information through the different phases in this systematic review was depicted using a PRISMA flow diagram, which mapped the number of records identified, included and excluded, and the reasons for exclusion. Our findings indicate that the frequency of different aetiologic agents of TC in the reported studies varied globally, from 0.4–87.7% in Africa, 0.2–74.0% in North America, 0.0–91.2% in Eastern Asia, 0.0–69.0% in Eastern Europe and 2.9–86.4% in Oceania. Microsporum canis is the most frequent reported zoophilic agent worldwide, while Trichophyton violaceum and Trichophyton tonsurans are the predominant anthropophilic agents. Over time, the frequency of these latter fungal infections has increased globally, and these fungi have become the major species globally. Anthropophilic transmission – the most prevalent type of transmission – could be explained by two factors: (i) the socioeconomic status of affected countries and population groups with associated risk factors and (ii) movement of populations importing new causes of infection to areas where they had not been encountered previously. We observed that intercontinental migration and travel; globalization; environmental, climatic and ecological changes; and accelerated evolution of health technologies may influence the observed epidemiological changes and, consequently, contributed to the variations in the global status of TC.
BackgroundCoccidioidomycosis, a potentially fatal fungal infection, is considered an emergent mycotic disease because of the increased incidence of fungal infections registered over recent years. Infection occurs through the inhalation of arthroconidia from two main species of Coccidioides: Coccidioides immitis and C. posadasii, which are both endemic to arid and semi-arid regions of North America. Coccidioides species not only infect humans but can also infect other mammals (land, aquatic, wild or domestic), reptiles and birds.ObjectiveTo obtain information regarding the habitat of Coccidioides spp. and the animals infected by this fungus and to identify the role that infected animals play as reservoirs and disseminators of this fungus in nature.MaterialsA literature review was conducted to identify the habitat of Coccidioides spp. and the infected non-human animal species targeted by this fungus.Results and conclusionsThis review allows us to suggest that Coccidioides spp. may be classified as halotolerant organisms; nevertheless, to perpetuate their life cycle, these organisms depend on different animal species (reservoirs) that serve as a link with the environment, by acting as disseminators of the fungi in nature.
Psoriasis is a common chronic inflammatory multisystemic disease with a complex pathogenesis consisting of genetic, immunological, and environmental components. It is associated with a number of comorbidities, including diabetes, metabolic syndrome, obesity, and myocardial infarction. In addition, the severity of psoriasis seems to be related to the severity of obesity. Patients with higher levels of obesity show poorer response to systemic treatments of psoriasis. Several studies have demonstrated that white adipose tissue is a crucial site of the formation of proinflammatory adipokines such as leptin, adiponectin, and resistin and classical cytokines such as interleukin- (IL-) 6 and tumour necrosis factor-α. In psoriasis, due to the proliferation of Th1, Th17, and Th22 cells, IL-22, among others, is produced in addition to the abovementioned cytokines. With respect to leptin and resistin, both of these adipokines are present in high levels in obese persons with psoriasis. Further, the plasma levels of leptin and resistin are related to the severity of psoriasis. These results strongly suggest that obesity, through proinflammatory pathways, is a predisposing factor to the development of psoriasis and that obesity aggravates existing psoriasis. Different inflammatory biomarkers link psoriasis and obesity. In this paper, the most important ones are described.
BACKGROUND:Onychomycosis are caused by dermatophytes and Candida, but rarely by non- dermatophyte molds. These opportunistic agents are filamentous fungi found as soil and plant pathogens.OBJECTIVES:To determine the frequency of opportunistic molds in onychomycosis.METHODS:A retrospective analysis of 4,220 cases with onychomycosis, diagnosed in a 39-month period at the Institute of Dermatology and Skin surgery "Prof. Dr. Fernando A. Cordero C." in Guatemala City, and confirmed with a positive KOH test and culture.RESULTS:32 cases (0.76%) of onychomycosis caused by opportunistic molds were confirmed. The most affected age group ranged from 41 to 65 years (15 patients, 46.9%) and females were more commonly affected (21 cases, 65.6%) than males. Lateral and distal subungual onychomycosis (OSD-L) was detected in 20 cases (62.5%). The microscopic examination with KOH showed filaments in 19 cases (59.4%), dermatophytoma in 9 cases (28.1%), spores in 2 cases (6.25%), and filaments and spores in 2 cases (6.25%). Etiologic agents: Aspergillus sp., 11 cases (34.4%); Scopulariopsis brevicaulis, 8 cases (25.0%); Cladosporium sp., 3 cases (9.4%); Acremonium sp., 2 cases (6.25%); Paecilomyces sp., 2 cases (6.25%); Tritirachium oryzae, 2 cases (6.25%); Fusarium sp., Phialophora sp., Rhizopus sp. and Alternaria alternate, 1 case (3.1%) each.CONCLUSIONS:We found onychomycosis by opportunistic molds in 0.76% of the cases and DLSO was present in 62.5%. The most frequent isolated etiological agents were: Aspergillus sp. and Scopulariopsis brevicaulis.
Since Candida auris integrates strains resistant to multiple antifungals, research has been conducted focused on knowing which molecular mechanisms are involved. This review aims to summarize the results obtained in some of these studies. A search was carried out by consulting websites and online databases. The analysis indicates that most C. auris strains show higher resistance to fluconazole, followed by amphotericin B, and less resistance to 5-fluorocytosine and caspofungin. In C. auris, antifungal resistance to amphotericin B has been linked to an overexpression of several mutated ERG genes that lead to reduced ergosterol levels; fluconazole resistance is mostly explained by mutations identified in the ERG11 gene, as well as a higher number of copies of this gene and the overexpression of efflux pumps. For 5-fluorocytosine, it is hypothesized that the resistance is due to mutations in the FCY2, FCY1, and FUR1 genes. Resistance to caspofungin has been associated with a mutation in the FKS1 gene. Finally, resistance to each antifungal is closely related to the type of clade to which the strain belongs.
The ability of Candida spp. to form biofilms is crucial for its pathogenicity, and thus, it should be considered an important virulence factor in vulvovaginal candidiasis (VVC) and recurrent VVC (RVVC). Its ability to generate biofilms is multifactorial and is generally believed to depend on the site of infection, species and strain involved, and the microenvironment in which the infection develops. Therefore, both cell surface proteins, such as Hwp1, Als1, and Als2, and the cell wall-related protein, Sun41, play a critical role in the adhesion and virulence of the biofilm. Immunological and pharmacological approaches have identified the NLRP3 inflammasome as a crucial molecular factor contributing to host immunopathology. In this context, we have earlier shown that Candida albicans associated with hyphae-secreted aspartyl proteinases (specifically SAP4-6) contribute to the immunopathology of the disease. Transcriptome profiling has revealed that non-coding transcripts regulate protein synthesis post-transcriptionally, which is important for the growth of Candida spp. Other studies have employed RNA sequencing to identify differences in the 1,245 Candida genes involved in surface and invasive cellular metabolism regulation. In vitro systems allow the simultaneous processing of a large number of samples, making them an ideal screening technique for estimating various physicochemical parameters, testing the activity of antimicrobial agents, and analyzing genes involved in biofilm formation and regulation ( in situ ) in specific strains. Murine VVC models are used to study C. albicans infection, especially in trials of novel treatments and to understand the cause(s) for resistance to conventional therapeutics. This review on the clinical relevance of Candida biofilms in VVC focuses on important advances in its genomics, transcriptomics, and proteomics. Moreover, recent experiments on the influence of biofilm formation on VVC or RVVC pathogenesis in laboratory animals have been discussed. A clear elucidation of one of the pathogenesis mechanisms employed by Candida biofilms in vulvovaginal candidiasis and its applications in clinical practice represents the most significant contribution of this manuscript.
The physiopathologic characteristics of COVID-19 (high levels of inflammatory cytokines and T-cell reduction) promote fungal colonization and infection, which can go unnoticed because the symptoms in both diseases are very similar. The objective of this work was to study the current epidemiology of systemic mycosis in COVID-19 times. A literature search on the subject (January 2020–February 2021) was performed in PubMed, Embase, Cochrane Library, and LILACS without language restrictions. Demographic data, etiological agent, risk factors, diagnostic methods, antifungal treatment, and fatality rate were considered. Eighty nine publications were found on co-infection by COVID-19 and pneumocystosis, candidiasis, aspergillosis, mucormycosis, coccidioidomycosis, or histoplasmosis. In general, the co-infections occurred in males over the age of 40 with immunosuppression caused by various conditions. Several species were identified in candidiasis and aspergillosis co-infections. For diagnosis, diverse methods were used, from microbiological to molecular. Most patients received antifungals; however, the fatality rates were 11–100%. The latter may result because the clinical picture is usually attributed exclusively to SARS-CoV-2, preventing a clinical suspicion for mycosis. Diagnostic tests also have limitations beginning with sampling. Therefore, in the remainder of the pandemic, these diagnostic limitations must be overcome to achieve a better patient prognosis.
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