INVESTIGAÇÃO DE Cryptococcus spp. E OUTRAS LEVEDURAS EM EXCRETAS DE AVES PRESENTES EM PRAÇAS PÚBLICAS DE CAMPO GRANDE, MS

Abstract

Soil is a rich habitat for microorganisms. The environment that has a high microbial load of fungi with pathogenic potential such as yeasts from the Cryptococcus neoformans and C. gattii complexes can favor the inhalation of infectious propagules and the development of diseases. These fungi are present in pigeon droppings (Columba livia) and decomposing tree trunks. Considering the existence of cases of cryptococcosis in Campo Grande, MS and few studies on the isolation of these yeasts in environmental samples, the objective of this research was to investigate the presence of Cryptococcus spp. and other yeasts of medical interest in public squares with high movement of people in Campo Grande, Mato Grosso do Sul. From July to October 2023. 50 samples of dry pigeon excrement were isolated from 3 public squares: Square A, B and C. The samples were seeded on Niger agar, and later the characteristic yeast colonies were picked on Sabouraud dextrose agar with chloramphenicol for conservation. In 25 (50%) pigeon excrement samples, 29 yeast colonies were selected. Of these, a direct mycological examination was carried out to observe microscopic aspects and identification using phenotypic techniques (canavanine-glycine-bromothymol blue-CGB agar, urea agar and auxanogram). Nine (31%) colonies of Cryptococcus spp., differentiated by conventional methods, were identified in the VITEK® 2 automated system. In the present research, the pathogenic species of the Cryptococcus neoformans and Cryptococcus gattii complexes were not identified. However, in 25 (50%) samples other yeasts were identified, such as Rhodotorula sp. (28%); Candida sp. (17%) and Sporobolomyces spp. (7%). Of the 14 colonies identified as Cryptococcus spp., 7 (50%) were Cryptococcus albidus and 5 (35%) Cryptococcus laurentii. The identification of medically important yeasts in busy urban areas, such as public squares, indicates a source of environmental contamination. The results of this study indicate that dried droppings from pigeons and other birds harbor yeast that can be airborne and cause disease in susceptible animals and individuals.