S5.4c Isolation of keratinophilic fungi of the genus Microsporum from the soils of Moscow, Russia
Authors: Manoyan Marina , Sokolov Vladimir , Panin Alexander , Gabuzyan Narine 
Published: September 2022

5.4 Free oral paper session, September 22, 2022, 3:00 PM - 4:30 PM

It is reported about the discovery of zoophilic and geophilic dermatophytes in the soils of city parks and adjacent territories of Moscow, Russia. Microscopic fungi of the Microsporum genus were found in 27/50 samples (54%): Microsporum gypseum (42%) and Microsporum canis (12%), their number was higher in the soils taken from the adjacent areas where domestic animals are walked. This increases the risk of infection of animals upon contact with soil.

Objectives

The research was conducted to determine the frequency of occurrence of potential pathogens of animal dermatophytosis in those areas of the soil cover where pets are walking. Soil samples were taken from several areas: the adjacent territories along the streets of Vishnevsky and Kostyakov, designated as areas 1 and 2, the park ‘Dubki’, Lianozovsky, Timiryazevsky, designated as 3, 4, and 5, respectively.

Areas 1 and 2 are narrow patches of soil adjacent to residential buildings and sidewalks where pets are most often walked. Areas 3 and 4 are areas of soil adjacent to park paths, where animal walking is less common. Area 5 is a relatively little-visited place in the forest park, where animals are rarely walked.

Methods

Before sampling, vegetation cover and rubbish were removed from the soil area, then ∼ 100 g of soil was taken from the surface using aseptic rules in sterile plastic containers. A total of 10 soil samples were taken from each plot. The soil was dried at room temperature, sieved to remove rubbish, and plant parts, and placed in sterile Petri dishes.

Isolation of fungi was carried out by the ‘bait’ method: samples of sterile pet hair about 1 cm long were placed on the surface of the soil, the soil was moistened with sterile distilled water with the addition of a selective additive for the isolation of dermatophytes (Dermasel, Oxoid). Petri dishes were periodically inspected for fungal growth on the surface of the wool and moistened if necessary.

When the growth of microscopic fungi was detected on the surface of the wool, they were sterilely transferred to Petri dishes with wort agar medium (M129, HiMedia) to obtain a pure culture and identification. Only microscopic fungi of the genus Microsporum were taken into account.

Results

As a result of the research, a total of 27 isolates of microscopic fungi, 21 of Microsporum gypseum and 6 of Microsporum canis were isolated from the soils of Moscow: 7 isolates at the area 1 (6 of M. gypseum, 1 of M. canis), 8 isolates at the area 2 (5 of M. gypseum, 3 of M. canis), 5 isolates at areas 3, and 5 (4 of M. gypseum, 1 of M. canis), 2 isolates of M. gypseum at the area 5. The results are illustrated in Figure 1.

Conclusion

Soils located in adjacent areas are more polluted by the hair of pets that walk there. Therefore, these soils also contain keratinophilic microscopic fungi, which includes the pathogens of animal dermatophytosis. In such places, animals are susceptible to infection with fungal infections directly from the soil.