Sporothrix brasiliensis infecting cats in northeastern Brazil: New emerging areas in Paraíba state

ABSTRACT: Sporotrichosis is a subcutaneous mycosis caused by fungus of the Sporothrix complex, and in Brazil the main species reported is Sporothrix brasiliensis, of which the diseased cat is the transmitter. Although, its occurrence has increased in the state of Paraíba, Brazil, since 2016, data on the disease in this state are limited. Therefore, this research aimed to identify molecularly isolates of Sporothrix spp. from domestic cats from cities in Paraíba, and in this way to expand the understanding of the disease in the state. Thirty-nine samples were analyzed, obtained from skin lesions of domestic felines, from the following cities in Paraíba: João Pessoa, Pilões, Patos, Areia, Bananeiras and Guarabira. Cytological analysis was performed to screen the samples, followed by fungal culture, and the molecular characterization of the isolates was performed, using the species-specific Polymerase Chain Reaction (PCR) or partial sequencing of the calmodulin gene. All isolates were identified as S. brasiliensis. The sequencing showed 100% similarity to the S. brasiliensis CBS 120339 strain. In view of this, it is concluded that in the study areas the species involved in cases of feline sporotrichosis is S. brasiliensis, its presence in Paraíba demonstrated the spread of the agent in regions distant from the epicenters in Brazil, alerting to the possible occurrence of zoonotic outbreaks similar to those found in the South and Southeast regions of the country. In addition, it highlights the emerging role of felines in the transmission of sporotrichosis in new endemic areas of Brazil.

摘要：孢子丝菌病（Sporotrichosis）是由孢子丝菌复合群（Sporothrix complex）真菌引发的皮下真菌病，在巴西已报道的主要致病菌种为巴西孢子丝菌（Sporothrix brasiliensis），患病猫为其传播媒介。自2016年以来，巴西帕拉伊巴州的孢子丝菌病病例数呈上升趋势，但该州相关疾病研究数据仍较为有限。为此，本研究旨在对帕拉伊巴州多个城市家猫分离的孢子丝菌属（Sporothrix spp.）菌株开展分子鉴定，以此深化对该州孢子丝菌病流行现状的认知。本研究共分析39份采自帕拉伊巴州若昂佩索阿（João Pessoa）、皮隆（Pilões）、帕托斯（Patos）、阿雷亚（Areia）、巴纳内拉斯（Bananeiras）及古拉巴拉（Guarabira）等地家猫皮肤病灶的样本。实验流程为先通过细胞学分析对样本进行初筛，随后开展真菌培养，再采用种特异性聚合酶链式反应（Polymerase Chain Reaction, PCR）或钙调蛋白基因（calmodulin gene）部分测序对分离株进行分子鉴定。结果显示，所有分离株均被鉴定为巴西孢子丝菌；测序结果表明其与巴西孢子丝菌CBS 120339菌株的同源性达100%。据此可得出结论：本研究涉及区域内引发家猫孢子丝菌病的病原体为巴西孢子丝菌；该菌种在帕拉伊巴州的检出证实，此病原体已扩散至巴西远离本土疫源地的区域，警示该国南部与东南部地区出现的人畜共患病暴发风险同样可能在本地发生。此外，本研究凸显了家猫在巴西新型流行区孢子丝菌传播中的新兴媒介作用。