Evaluation of two molecular techniques for rapid detection of the main dermatophytic agents of tinea capitis

Detection of emerging genotypes in Trichophyton mentagrophytes species complex: A proposal for handling biodiversity in dermatophytes

A resistant and hypervirulent dermatophyte from India has been described as a taxonomic novelty, Trichophyton indotineae, a species of the Trichophyton mentagrophytes complex. Rapid detection and correct identification of closely similar dermatophytes with different predilections are essential for efficient clinical management. We evaluated the efficacy of rapid diagnostic methods clinical and environmental strains in the T. mentagrophytes complex. The methods included Real-time-PCR, DermaGenius, LAMP, and MALDI-ToF MS, using rDNA ITS sequences as taxonomic standard. The results show that only MALDI-ToF MS can distinguish 96.97% T. indotineae from other closely related species. The complex comprises numerous clones which may differ in anonymous markers but with similar evolutionary behavior. Therefore, we recommend to distinguish species only when they show an appreciable degree of adaptation and thus are clinically significant. The distinction of remaining clonal diversity is an epidemiological query and can be solved by haplotype numbering.

Isothermal nucleic acid amplification techniques for detection and identification of pathogenic fungi: A review

BACKGROUND

Fungal infections have increased during the last years due to the AIDS epidemic and immunosuppressive therapies. The available diagnostic methods, such as culture, histopathology and serology, have several drawbacks regarding sensitivity, specificity and time-consuming, while molecular methods are still expensive and dependent on many devices. In order to overcome these challenges, isothermal nucleic acid amplification techniques (INAT) arose as promising diagnostic methods for infectious diseases.

OBJECTIVE

This review aimed to present and discuss the main contributions of the isothermal nucleic acid amplification techniques applied in medical mycology.

METHODS

Papers containing terms for each INAT (NASBA, RCA, LAMP, CPA, SDA, HAD or PSR) and the terms 'mycoses' or 'disease, fungal' were obtained from National Center for Biotechnology Information database until August 2019.

RESULTS

NASBA, RCA, LAMP and PSR are the INAT reported in the literature for detection and identification of pathogenic fungi. Despite the need of a previous conventional PCR, the RCA technique might also be used for genotyping or cryptic species differentiation, which may be important for the treatment of certain mycoses; nevertheless, LAMP is the most used INAT for pathogen detection.

CONCLUSION

Among all INATs herein reviewed, LAMP seems to be the most appropriate method for fungal detection, since it is affordable, sensitive, specific, user-friendly, rapid, robust, equipment-free and deliverable to end-users, fulfilling all ASSURED criteria of the World Health Organization for an ideal diagnostic method.

Anti-tumor effects of engineered mesenchymal stem cells in colon cancer model

Background

Cell-based gene therapy is considered as a promising strategy for the treatment of human malignancy. In many different types of cancer, mesenchymal stem cells (MSCs) are observed as valuable and potential anti-cancer agents. However, the exact mechanisms of MSCs involved in tumor microenvironment are not well understood.

Aim

Our aims are to elucidate the MSCs-mediated tumor microenvironment.

Materials and methods

In this study, colon cancer model was established by injecting the HT29 cells into the subcutaneous of right axilla of nude mice. We applied the human placenta-derived MSCs (hP-MSCs) armed with a double fusion gene containing the herpes simplex virus truncated thymidine kinase and firefly luciferase for treatment of colon cancer on days 10, 15, and 20 after HT29 cells injection. Molecular imaging methods were used for real-time imaging tumor progression and tracking transplanted hP-MSCs by bioluminescence imaging. Furthermore, proliferation and apoptosis-related proteins levels in colon cancer tissues were examined by immunofluorescence and Western blotting.

Results

Our results demonstrated that the administration of engineered hP-MSCs significantly inhibited the tumors and this effect was enhanced by ganciclovir application. Further analysis demonstrated the anti-tumor effect of engineered hP-MSCs in vivo depended on inhibiting tumor proliferation and inducing tumor apoptosis.

Conclusion

Collectively, this work showed that engineered hP-MSCs could inhibit colon cancer progression and metastasis by inducing tumor cell death and suppressing proliferation.

Tinea Capitis: Current Status

Tinea capitis remains a common childhood infection in many parts of the world. Yet knowledge of the underlying pathogenetic mechanisms and the development of effective immunity have shown striking advances, and new methods of diagnosis ranging from dermoscopy to molecular laboratory tests have been developed even though they have not been assimilated into routine practice in many centres. Treatment is effective although it needs to be given for at least 1 month. What is missing, however, is a systematic approach to control through case ascertainment and therapy.