The epidemiological and mycological profile of superficial mycoses in india from 2015 to 2021: A systematic review

Background

The epidemiological and mycological patterns of superficial mycoses across various geographic regions of India across the last few years are changing.

Objective

This study was performed to evaluate the epidemiological and mycological profile of superficial mycoses in India between 2015 and 2021.

Methods

In this systematic review, the PubMed database was searched for all observational studies published between January 1, 2015, and December 31, 2021, which had evaluated the clinico-mycological profile of superficial mycoses among outpatients from various parts of India. Descriptive statistics was used to represent the results.

Results

Forty studies (21 from the north, three from the northeast, five from the east, seven from the south, one from the west, and three from multiple regions of India) were included. Male patients and those of the age group of 21-40 years were most commonly affected. The proportion of dermatophytes as causative organisms was consistently high across all regions and throughout the study period (23.6%-100%). Among dermatophytes, the proportion of Trichophyton mentagrophyte (14.0%-97.2%) and Trichophyton rubrum (0%-69.1%) was consistently high across all regions. The prevalence of T. mentagrophyte showed a rising trend, while that T. rubrum showed a declining trend from 2015 to 2021.

Conclusions

The epidemiological and mycological pattern of superficial mycoses showed a fairly similar trend across various regions of India from 2015 to 2021. Dermatophytes were the main causative agents of superficial mycoses; the most common species were T. mentagrophyte and T. rubrum. A rising trend of T. Mentagrophyte infection was found.

Assessment of the mechanism of drug resistance in Trichophyton mentagrophytes in response to various substances

BACKGROUND

Trichophyton mentagrophyte (TM), a zoonotic pathogen, has been endangering public health due to emerging drug resistance. Although increased attention is paid to this issue, there is very limited research available on drug resistance in TM. In this study, we studied the gene and proteomic changes, morphological changes, cellular fat localization, fat content changes, and biofilm of TM treated with different substances.

RESULTS

The TM growth curve showed a positive correlation with the concentration of Fenarimol (FE), genistein (GE), clotrimazole (KM), and Miconazole nitrate salt (MK). The morphology of TM cells changed in different degrees after treatment with different substances as observed by TEM and SEM. The results showed that under KM and berberine hydrochloride (BB) treatment, a total of 3305 differentially expressed genes were detected, with the highest number in the KM-treated group (578 up-regulated and 615 down-regulated). A total of 847 proteins and 1850 peptides were identified in TM proteomics. Nile red staining showed that the fat content of TM was significantly higher in the BB-, ethidium bromide- (EB), FE-, KM-, Adriamycin hydrochloride- (YA), and MK-treated group compared to the control group. Results of the biofilm thickness showed that it gradually increased under treatment with specific concentrations of KM or BB, which may be related to the up-regulation of ERG25 and CYP related gene proteins.

CONCLUSIONS

It is suggested that in order to effectively deal with dermatomycosis caused by TM, it is necessary to inhibit the expression of ERG25 and CYP related genes and fat metabolism, which can result in the inhibition of the production of biofilm by the fungus and solve the problem of fungal drug resistance in clinical settings.

MIC and Upper Limit of Wild-Type Distribution for 13 Antifungal Agents against a Trichophyton mentagrophytes-Trichophyton interdigitale Complex of Indian Origin

Dermatophytosis due to the Trichophyton mentagrophytes-Trichophyton interdigitale complex is being increasingly reported across India. Reports of therapeutic failure have surfaced recently, but there are no clinical break points (CBP) or epidemiological cutoffs (ECVs) available to guide the treatment of dermatophytosis. In this study, a total of 498 isolates of the T. mentagrophytes -interdigitale complex were collected from six medical centers over a period of five years (2014 to 2018). Antifungal susceptibility testing of the isolates was carried out for itraconazole, fluconazole, ketoconazole, voriconazole, luliconazole, sertaconazole, miconazole, clotrimazole, terbinafine, amorolfine, naftifine, ciclopirox olamine, and griseofulvin. The MICs (in mg/liter) comprising >95% of the modeled populations were as follows: 0.06 for miconazole, luliconazole, and amorolfine; 0.25 for voriconazole; 0.5 for itraconazole, ketoconazole, and ciclopirox olamine; 1 for clotrimazole and sertaconazole; 8 for terbinafine; 16 for naftifine; 32 for fluconazole; and 64 for griseofulvin. A high percentage of isolates above the upper limit of the wild-type MIC (UL-WT) were observed for miconazole (29%), luliconazole (13.9%), terbinafine (11.4%), naftifine (5.2%), and voriconazole (4.8%), while they were low for itraconazole (0.2%). Since the MICs of itraconazole were low against the T. mentagrophytes -interdigitale complex, this could be considered the choice of first-line treatment. The F397L mutation in the squalene epoxidase (SE) gene was observed in 77.1% of isolates with a terbinafine MIC of ≥1 mg/liter, but no mutation was detected in isolates with a terbinafine MIC of <1 mg/liter. In the absence of CBPs, evaluation of the UL-WT may be beneficial for managing dermatophytosis and monitoring the emergence of isolates with reduced susceptibility.