Mycological Aspects of Onychomycosis in Khuzestan Province, Iran, a New Scenario as Shift from Dermatophytes towards Yeasts

Abstract

Background and Purpose:Onychomycosis is fungal infection of the nails with an overall increasing incidence, worldwide. The epidemiological aspects of onychomycosis in Khuzestan, Iran, have not been established. In this study, we aimed to evaluate the clinical and mycological status of fungal nail infection in Khuzestan Province, Iran.Materials and Methods:The study population included 433 patients (143 males vs. 290 females). Nail samples underwent primary direct microscopy and culture. The isolated yeasts and dermatophytes were then subjected to additional molecular identification by r-DNA ITS-RFLP. Identification of some non-dermatophytic molds (NDMs) and unknown yeasts was accomplished by ITS and beta-tubulin sequencing.Results:Onychomycosis was confirmed in 154 patients (males: 36.4%; n=56 vs. females: 63.6%; n=98), whose age ranged from 2 to 85 years, with the highest prevalence in the age group of 41-50 years. Infection mostly occurred due to yeasts (57.15%), with Candida albicans as the most frequent (29.35%) species, followed by C. parapsilosis (13.8%) and C. tropicalis (4.5%). Dermatophytes were isolated in 38.35% of the cases; the most common isolates were found to be Trichophyton interdigitale (21.1%), Epidermophyton floccosum (10.5%), T. rubrum (5.25%), and Microsporum canis (1.5%). NDMs were isolated from 4.5% of the cases with Aspergillus spp. as the most common agent. Dermatophytes and NDMs were more frequently seen in toenails, whereas yeasts mostly infected fingernails. Fingernail onychomycosis was significantly more prevalent among females than in males (P<0.05).Conclusion:The study highlights that in Khuzestan province, the causative agents of onychomycosis have shifted from dermatophytes to yeasts.

A 15‐year retrospective study on the prevalence of onychomycosis in psoriatic vs non‐psoriatic patients: A new European shift from dermatophytes towards yeast

“…Our data are in contrast with current available literature on the global epidemiology of onychomycosis, but they trace an epidemiological shift already reported in Iran, Brazil, India and Saudi Arabia . In fact, as reported, respectively, for the countries mentioned before, yeasts were found to be the causative agents of onychomycosis in the following: 59.7% in Iran, in Brazil, in 47.86% India and 46.8% in Saudi Arabia …”

Non‐dermatophyte fungi in onychomycosis—Epidemiology and consequences for clinical practice

“…in 50% of the nail samples, dermatophytes in 21% and ND moulds in 11% 2 . Similar fungal epidemiologies of onychomycoses were observed in surveys conducted in countries of the Middle East, Asia and South America 14‐17 . In a review on the worldwide prevalence of onychomycosis, Gupta et al 6 identified ND moulds as causative pathogens in roughly half of the onychomycosis cases for some regions.…”

“…In a review on the worldwide prevalence of onychomycosis, Gupta et al 6 identified ND moulds as causative pathogens in roughly half of the onychomycosis cases for some regions. These observations may in fact indicate an epidemiological trend towards an increased involvement of non‐dermatophyte pathogens in onychomycosis 14 …”

Cryptic species of Aspergillus section Terrei display essential physiological features to cause infection and are similar in their virulence potential in Galleria mellonella

“…No speciesdependent difference was observed in hypoxic cultures, leading to the assumption that all species are similarly able to cause invasive disease, as also reflected by clinical data. Only A. floccosus has so far never been described to cause invasive disease [21,37].…”