Comparative evaluation of host immune response and cytokine signature pertaining to Th1 and Th2 immune arms in serum and tissue among patients of acute localised vs. chronic disseminated dermatophytosis

Clinico-mycological and therapeutic updates on cutaneous dermatophytic infections in the era of Trichophyton indotineae

Trichophyton indotineae has emerged as a novel dermatophyte species resulting in treatment recalcitrant skin infections. While the earliest reports came from India, T. indotineae has now spread to many parts of the world and is rapidly becoming a global health concern. Accurate identification of T. indotineae requires elaborate mycological investigations which is beyond the domain of routine microbiology testing. Extensive, non-inflammatory and atypical presentations are commonly seen with this novel species. T. indotineae shows an alarmingly high rate of mutations in the squalene epoxidase gene leading to lowered in vitro susceptibility to terbinafine. This has also translated into a lowered clinical response and requirement of a higher dose and much longer durations of treatment with the drug. Although the species remains largely susceptible to itraconazole, prolonged treatment durations are required to achieve cure with itraconazole. Fluconazole and griseofulvin do not have satisfactory in vitro or clinical activity. Apart from requirement of prolonged treatment durations, relapse postsuccessful treatment is a distressing and yet unexplained consequence of this "species-shift." Use of third generation azoles and combinations of systemic antifungals is unwarranted as both have not demonstrated clear superiority over itraconazole given alone, and the former is an important class of drugs for invasive mycoses.

Drosophila melanogaster as a model of systemic dermatophytosis

BACKGROUND

Dermatophytosis is one of the most common fungal infections worldwide. The distribution of dermatophytes varies across continents, but the genera Trichophyton and Microsporum have emerged as the main isolated agents in humans and animals.

OBJECTIVES

To validate Drosophila melanogaster flies as a fast and feasible model to study dermatophytic infections.

METHODS

Wild-type (WT) and Toll-deficient D. melanogaster flies were infected by Trichophyton rubrum, T. mentagrophytes, Microsporum canis and Nannizzia gypsea by pricking with a needle previously dipped in inoculum concentrations ranging from 103 to 108 colony-forming units/mL. Establishment of infection was confirmed by survival curves, histopathological analysis and fungal burden. Thereafter, flies were treated with terbinafine, itraconazole and clioquinol.

RESULTS

WT flies were predominantly resistant to the infection, whereas Toll-deficient flies succumbed to the four dermatophyte genera tested. The antifungal drugs protected flies from the infection, except for N. gypsea whose survival curves did not differ from the untreated group.

CONCLUSIONS

This pilot study confirms that D. melanogaster is a suitable model to study the virulence and antifungal drug efficacy in dermatophyte species.

Study on the Relationship Between Bronchoalveolar Lavage Fluid Cell Count, Th1/Th2 Cytokines and Pulmonary Function in Patients with Cough Variant Asthma

OBJECTIVE

This study aimed to compare lung function and airway inflammation among cough variant asthma (CVA), chronic cough and classical asthma (CA) and investigate the relationship between these indicators and their possible mechanisms of action in the progression of CVA to CA.

METHODS

36 patients with chronic cough, 39 patients with CA, and 57 patients with CVA were included in this study. Pulmonary function tests, bronchial provocation tests and FeNO tests were performed. The patients' bronchoalveolar lavage fluid (BALF) was collected, the cells in BALF were counted, and the levels of Th1 and Th2 cytokines were detected.

RESULTS

The neutrophils, lymphocytes, and eosinophils in BALF in the CA and CVA groups were significantly higher than those in the chronic cough group. Also, they were negatively correlated with FEV1, FVC, and FEV1/FVC and positively correlated with IgE and FeNO. The expression of Th2-related cytokines was increased in CVA and CA patients, and it was positively correlated with FEV1, FVC and FEV1/FVC and negatively correlated with IgE and FeNO, while the results of Th1-related cytokines were the opposite of those for Th2-related cytokines.

CONCLUSION

CVA differs from asthma and chronic cough in terms of Th1/Th2 cytokines and lung function and provides a reference for understanding the disease mechanism of early clinical progression of CVA to CA.