Sporothrix spp. EVALUATION IN SOIL OF A HYPERENDENIC AREA FOR SPOROTRICHOSIS IN SOUTHERN BRAZIL

Abstract The increase in zoonotic sporotrichosis cases has become a public health problem in hyperendemic areas for the feline disease. Domestic cats involvement in this transmission and the continuous contact of these animals with soil suggest that the environment may be an essential source and/or reservoir of Sporothrix spp. Thus, the current study aimed to evaluate the presence of Sporothrix spp. in the soil of places where infected cats in Southern Brazil is present. In total, 101 soil samples were collected from the residence of cats with sporotrichosis, from regions around to these residences, and also from public places. These samples were processed using the direct plating technique being incubated at 25 °C for up to 15 days. Additionally, seventeen samples were also submitted to DNA extraction (NORGEN BIOTEK CORP® kit), PCR-specific and Nested-PCR technique. Although the presence of Sporothrix in soil has been undetected, by culture or molecular biology, this study does not reject the role of the environment in the triad of the infectious process (soil-animal-human). Thus, further studies are necessary for expanding the area of coverage, volume, type and method of sampling, and/or detection techniques.

摘要 人畜共患孢子丝菌病病例的增加，已在该猫类疾病的高流行地区成为一项公共卫生问题。家猫参与该疾病的传播链，且此类动物与土壤存在持续接触，提示环境可能是申克孢子丝菌属（Sporothrix spp.）的关键传染源和/或储存宿主。因此，本研究旨在评估巴西南部孢子丝菌病患猫所在场所的土壤中是否存在申克孢子丝菌属。本研究共采集101份土壤样本，采样地点涵盖患猫居所、居所周边区域以及公共场所。所有样本均采用直接涂布平板法进行前处理，并于25℃条件下培养至多15天。此外，另有17份样本采用NORGEN BIOTEK CORP®试剂盒完成DNA提取，并开展了特异性PCR与巢式PCR（Nested-PCR）检测。尽管通过培养法与分子生物学方法均未在土壤中检测到申克孢子丝菌属，但本研究并未否定环境在"土壤-动物-人"这一感染传播三联体中的作用。因此，未来需开展进一步研究，扩大采样覆盖范围、提升样本量、优化采样类型与采样方法，并完善检测技术。