Faculty of Veterinary Science, Prince of Songkla University, Songkhla 90110, Thailand.
Med Mycol. 2022 Sep 30;60(9). doi: 10.1093/mmy/myac075.
Feline sporotrichosis caused by the Sporothrix schenckii complex is a global subcutaneous mycosis, having higher prevalence in Latin America and Malaysia. However, its etiological agents have not been elucidated in Thailand, a neighboring country of Malaysia, where the cases are increasing. This study identified 38 feline isolates of S. schenckii from Southern Thailand, collected between 2018 and 2021, using phenotypic characterization and molecular identification using polymerase chain reaction (PCR)-sequencing of partial calmodulin (CAL) and ß-tubulin (Bt2) genes. Phenotypic characteristics proved that the isolates were S. schenckii sensu lato, with low thermotolerance. Based on partial CAL and Bt2-PCR sequencing, all isolates were identified as S. schenckii sensu stricto. Phylogenetic analyses revealed that the isolates were clustered with S. schenckii sensu stricto isolated from the cats in Malaysia. A low degree of genetic diversity was observed among the Thai feline isolates. The antifungal susceptibility of these isolates to antifungal agents, including itraconazole (ITC), ketoconazole (KTC), fluconazole (FLC), and amphotericin B (AMB), was investigated according to the M27-A3 protocol of the Clinical and Laboratory Standards Institute. Results showed low ITC, KTC, and AMB activities against S. schenckii sensu stricto isolates, with high minimum inhibitory concentration (MIC) ranges of 1-8, 1-8, and 2-16 μg/ml, respectively, whereas FLC exhibited MICs of 64 and > 64 μg/ml. This study indicated that S. schenckii sensu stricto is the causative agent responsible for feline sporotrichosis in Southern Thailand. Their phenotypic characteristics and in vitro antifungal susceptibility profiles will help to improve our understanding of this mycosis in Thailand.
由申克孢子丝菌复合体引起的猫孢子丝菌病是一种全球性的皮下真菌病，在拉丁美洲和马来西亚更为普遍。然而，在马来西亚的邻国泰国，这种疾病的病因尚未阐明，病例却在不断增加。本研究使用表型特征和聚合酶链反应（PCR）-测序部分钙调蛋白（CAL）和β-微管蛋白（Bt2）基因的分子鉴定，从泰国南部 2018 年至 2021 年采集的 38 株猫申克孢子丝菌分离株。表型特征证明分离株为申克孢子丝菌亚种，耐热性低。基于部分 CAL 和 Bt2-PCR 测序，所有分离株均被鉴定为申克孢子丝菌亚种。系统发育分析显示，分离株与从马来西亚猫中分离的申克孢子丝菌亚种聚集在一起。在泰国猫分离株中观察到遗传多样性程度较低。根据临床和实验室标准协会的 M27-A3 方案，对这些分离株对伊曲康唑（ITC）、酮康唑（KTC）、氟康唑（FLC）和两性霉素 B（AMB）等抗真菌药物的敏感性进行了研究。结果表明，申克孢子丝菌亚种对 ITC、KTC 和 AMB 的活性较低，MIC 范围分别为 1-8、1-8 和 2-16μg/ml，而 FLC 的 MIC 为 64 和>64μg/ml。本研究表明，申克孢子丝菌亚种是导致泰国南部猫孢子丝菌病的病原体。它们的表型特征和体外抗真菌药敏谱将有助于提高我们对泰国这种真菌病的认识。
