Prevalence of Microsporum canis from Pet Cats in Small Animal Hospitals, Chiang Mai, Thailand

Dermatophytosis is a disease caused by dermatophytes, a group of fungi that can cause disease both in humans and animals. The important genera that are pathogenic in animals include Trichophyton and Microsporum. Microsporum canis is an important species because it can cause zoonosis and is commonly found in domestic animals. Cats, which live very close to humans, may expose humans to this pathogen. This research focused on the epidemiology of M. canis found in cats. Hair samples were collected via the Mackenzie technique from cats with and without skin lesions, preliminarily examined with 10% KOH preparation, and cultured for fungal identification. Samples were confirmed with molecular techniques including polymerase chain reaction, gel electrophoresis, and sequencing. Samples were collected from 138 cats located in 93 households, 43 from cats with skin lesions (31.16%) and 95 from cats without skin lesions (68.84%). Eighteen cats with lesions (13.04%) and ten cats without lesions (7.2%) were found to carry M. canis. In eleven of the eighteen cats both with skin lesions and positive for M. canis (61.11%), the pathogen was found both at the site of the lesion and at other sites in the body. Because the pathogen can be found in the hair of cats with and without skin lesions, owners, keepers, veterinarians, and others who come into contact with these animals are at risk of infection if they are not aware or do not take precautions after contact with them.

CÁC CHỦNG VI NẤM NGOÀI DA PHÂN LẬP ĐƯỢC VÀ ĐỘ NHẠY CẢM VỚI CÁC THUỐC KHÁNG NẤM HIỆN NAY TRÊN BỆNH NHÂN ĐẾN KHÁM TẠI BỆNH VIỆN DA LIỄU THÀNH PHỐ HỒ CHÍ MINH NĂM 2021

Đặt vấn đề: Nhiễm vi nấm ngoài da (dermatophytosis) là một trong những bệnh phổ biến và khó điều trị. Vấn đề chẩn đoán tác nhân gây bệnh chưa được quan tâm triệt để, cộng với tình trạng kháng thuốc ngày càng tăng. Do đó cần thiết phải có nghiên cứu khảo sát các chủng vi nấm ngoài da hiện đang lưu hành trên các bệnh nhân đến khám tại bệnh viện Da Liễu, từ đó có cơ sở chẩn đoán và điều trị hiệu quả. Mục tiêu: Phân lập, định danh và tìm hiểu tỷ lệ của các chủng vi nấm ngoài da. Khảo sát độ nhạy cảm với các thuốc khám nấm hiện nay trên các bệnh nhân đến khám tại bệnh viện Da Liễu Thành phố Hồ Chí Minh. Phương pháp nghiên cứu: cắt ngang mô tả, đối tượng từ 339 mẫu bệnh phẩm da, tóc, móng nghi ngờ do vi nấm ngoài da đến khám ngoại trú tại Khoa Khám bệnh Bệnh viện Da Liễu Thành phố Hồ Chí Minh từ tháng 1 đến tháng 5 năm 2021 có chỉ định soi tươi tìm vi nấm của bác sĩ lâm sàng. Các bệnh phẩm được cấy vào môi trường Dermatophyte test medium (DTM) và Sabouraud dextrose Agar (SDA) để phân biệt và định danh. Các chủng vi nấm ngoài da được thực hiện kháng nấm bằng phương pháp đĩa khuếch tán để đánh giá hiệu lực gồm các chất kháng nấm: fluconazole, griseofulvin, itraconazole, ketoconazole. Kết quả: Tỷ lệ bệnh nhân được chẩn đoán nhiễm nấm ngoài da là 47,2%. Trên 107 mẫu bệnh phẩm nuôi cấy phân lập được vi nấm ngoài da, Trichophyton rubrum chiếm tỉ lệ cao nhất là 63,55%, kế đến là Trichophyton mentagrophytes với tỉ lệ 28,04%, Microsporum gypseum chiếm tỉ lệ 4,67%, và cuối cùng là Microsporum canis có tỉ lệ thấp nhất là 3,74%. Tất cả vi nấm ngoài da đều nhạy với thuốc kháng nấm itraconazole (100%); trong khi đó, mức độ nhạy cảm với griseofulvin là 98%. Đối với thuốc kháng nấm ketoconazole, mức độ nhạy với thuốc đạt 52,9%, và có 30,4% mẫu vi nấm ngoài da kháng với ketoconazole. Kết luận: Tỉ lệ nhiễm nấm da do vi nấm ngoài da của bệnh nhân còn cao; trong đó, loài Trichophyton rubrum là loài thường gặp nhất. Kết quả kháng nấm đồ cho thấy tình trạng đề kháng ngày càng tăng của vi nấm, có thể giảm hiệu quả điều trị.

Evaluation of the Multiplex Real-Time PCR DermaGenius® Assay for the Detection of Dermatophytes in Hair Samples from Senegal

For the successful treatment of dermatophytoses, especially tinea capitis, there is a need for accurate and rapid diagnostic methods. A lot of recent literature has focused on the detection of dermatophytes directly on sample material such as nails, hair and skin scrapings. Molecular tools offer the ability to rapidly diagnose dermatophytosis within 48 h. This study aimed to compare the results of a commercial real-time PCR (real-time PCR) assay DermaGenius®(DG) 2.0 complete multiplex kit with those of conventional diagnostic methods (direct microscopy and culture). A total of 129 hair samples were collected in Dakar (Senegal) from patients suspected of dermatophytosis. DG was applied for the molecular detection of Candida albicans, Trichophyton rubrum/soudanense, T. interdigitale, T. tonsurans, T. mentagrophytes, T. violaceum, Microsporum canis, M. audouinii, Epidermophyton floccosum, T. benhamiae and T. verrucosum. Dermatophytes species and C. albicans were differentiated by melting curve analysis. The sensitivity and specificity of the PCR assay were 89.3% and 75.3%, respectively. DG PCR was significantly more sensitive than culture (p < 0.001). DG PCR is fast and robust to contamination. In this paper, the main questions discussed were the replacement of culture by a broad-spectrum fungal real-time PCR and the implementation of DG PCR into a routine laboratory in Senegal.

Comparative characteristics of different methods of treatment of microsporia

Microsporia is the most common disease of fungal etiology, most often caused by the pathogen Microsporum canis. Treatment of this disease requires a comprehensive approach, because the disease is dangerous to humans. Therefore, in the treatment of microspores, it is important not only to carry out therapeutic measures, but also to prevent the spread of the pathogen of the fungus in the environment and increase the immune status of the organism in the fight against infection. The main source of infection is cats. In order to determine the effectiveness of treatment of microsporia by various methods, studied of the blood and skin of guinea pigs infected with the pathogen M. canis. Sick animals were divided into three groups. The first group was treated with the systemic antifungal itraconazole and topical treatment with a solution of clotrimazole. Treatment of the second group was performed with a topical antifungal agent (1% solution of clotrimazole) with vaccination with the antifungal vaccine “Vakderm”. For the third group, the developed drugs were used – antifungal agent “Micromar” and immunostimulant “Biogluk”. During treatment, hematological and immunological blood researches and histological skin examinations were performed. During treatment with antifungal drugs (itraconazole and clotrimazole) the number of leukocytes decreases from 11.13 ± 0.72 to 7.13 ± 0.22, rod-shaped neutrophils from 15.76 ± 1.29 to 5.50 ± 0.76, and segmental increases from 12.17 ± 1.47 to 24.17 ± 2.27, decreases ESR from 5.67 ± 0.67 to 2.33 ± 0.42, which occurs when inhibiting the inflammatory response of the organism to infection. Thrombocytopenia (from 231.17 ± 7.60 to 184.33 ± 7.65) and eosinophilia (from 2.70 ± 0.73 to 7.33 ± 1.33) are also noted. There is a slight increase in T-helpers and a decrease in T-suppressors. Histologically, the infiltration of the dermis by histiocytes and eosinophils under skin persists. In the treatment of microsporia by treatment with 1 % solution of clotrimazole and vaccination with the vaccine “Vakderm” the results of studies showed that the number of leukocytes decreases from 11.13 ± 0.72 to 5.35 ± 0.31 (P < 0.01), rod-shaped neutrophils from 15.76 ± 1.29 to 7.67 ± 0.56, and segmental increases from 12.17 ± 1.47 to 22.17 ± 0.91 (P < 0.001), decreases). The number of T-helpers is increasing. The histological picture on day 7 is characterized by hyperkeratosis, and on day 14 the hyperemia of the basal layer of the epidermis persists. When using the antifungal drug “Micromar” and immunostimulant “Biogluk” the results of studies showed that the number of leukocytes decreases from 11.13 ± 0.72 to 6.95 ± 0.10, rod-shaped neutrophils from 15.76 ± 1.29 to 6.17 ± 0.65, and segmental increases from 12.17 ± 1.47 to 22.00 ± 0.86, decreases ESR from 5.67 ± 0.67 to 2.17 ± 0.31. Increases the number of T-helpers and the number of natural killers and T-suppressors is gradually decreasing. Histological changes are presented in the form of dilation of blood vessels and visualization of single erythrocytes in the dermis on day 14 of treatment.

Subtyping Options for Microsporum canis Using Microsatellites and MLST: A Case Study from Southern Italy

Microsporum canis is considered one of the most common zoophilic dermatophyte species causing infections in animals and humans worldwide. However, molecular epidemiological studies on this dermatophyte are still rare. In this study, we aimed to analyse the population structure and relationships between M. canis strains (n = 66) collected in southern Italy and those isolated from symptomatic and asymptomatic animals (cats, dogs and rabbits) and humans. For subtyping purposes, using multilocus sequence typing (MLST) and multilocus microsatellite typing (MLMT), we first used a limited set of strains to screen for variability. No intraspecies variability was detected in six out of the eight reference genes tested and only the ITS and IGS regions showed two and three sequence genotypes, respectively, resulting in five MLST genotypes. All of eight genes were, however, useful for discrimination among M. canis, M. audouinii and M. ferrugineum. In total, eighteen microsatellite genotypes (A–R) were recognized using MLMT based on six loci, allowing a subdivision of strains into two clusters based on the Bayesian iterative algorithm. Six MLMT genotypes were from multiple host species, while 12 genotypes were found only in one host. There were no statistically significant differences between clusters in terms of host spectrum and the presence or absence of lesions. Our results confirmed that the MLST approach is not useful for detailed subtyping and examining the population structure of M. canis, while microsatellite analysis is a powerful tool for conducting surveillance studies and gaining insight into the epidemiology of infections due to this pathogen.

Galvos plaukuotosios dalies grybelis: epidemiologija, etiopatogenezė, klinika, diagnostika ir gydymo būdai

Tinea capitis (TC) yra dermatofitų sukelta galvos plaukuotosios dalies infekcija, kuri pažeidžia plaukus ir besiribojančią odą. Dažniausiai pažeidžiami vaikai iki lytinio brendimo, tačiau gali sirgti ir kitų amžiaus grupių asmenys. Pagrindiniai sukėlėjai yra Trichopyton ir Microsporum genčių zoofilinės ir antrofilinės rūšys. Nors Europoje stebimas bendras antropofilinių galvos odos infekcijų skaičiaus augimas, tačiau Microsporum canis išlieka vyraujantis sukėlėjas. Skirtingų rūšių grybeliai gali sukelti uždegiminius ir neuždegiminius klinikinius požymius. Sergant Tinea capitis, visada būtinas sisteminis gydymas, nes vietiniai priešgrybeliniai vaistai neprasiskverbia į plaukų folikulus ir medikamentas turi būti pasirinktas atsižvelgiant į konkretų ligos sukėlėją.

In vitro Activity of Allicin Alone and in Combination With Antifungal Drugs Against Microsporum canis Isolated From Patients With Tinea Capitis

The checkerboard broth method based on the Clinical and Laboratory Standards Institute M38-A3 document was used in this study to evaluate the in vitro activity of allicin alone and in combination with the antifungal drugs (griseofulvin, fluconazole, itraconazole and terbinafine) against Microsporum canis isolated from patients with tinea capitis. When allicin was used alone, only weak anti-M. canis effects were found. The MIC50, MIC90 and geometric mean (GM) of terbinafine were the lowest among the compounds tested. Synergism was observed for the combinations of allicin with itraconazole and terbinafine. Only indifference was observed for the combinations of allicin with griseofulvin and fluconazole. Our study illustrated the synergism of allicin in combination with itraconazole and terbinafine, which could be a reference for the treatment of tinea capitis due to M. canis.