Laboratory of Medical Mycology, Graduate School of Medicine, Teikyo University, Tokyo, Japan.
Institute of Medical Mycology, Teikyo University, Tokyo, Japan.
Med Mycol. 2024 Aug 2;62(8). doi: 10.1093/mmy/myae085.
Cryptococcosis is an important fungal infection for both humans and cats, but molecular epidemiological studies on strains isolated from cats are limited. We conducted multi-locus sequence typing analysis and antifungal susceptibility testing of 14 Cryptococcus spp. strains from domestic cats in Japan and one strain isolated from a cat in Singapore. All 14 strains from domestic cats in Japan were identified as Cryptococcus neoformans molecular type VNI. The sequence types (STs) included eight cases of ST5, five cases of ST31, and one novel ST. VNI ST5 is the most frequently isolated strain in Japanese patients as well, while there are no records of VNI ST31 being isolated from Japanese patients. The Singaporean cat strain was identified as C. gattii VGIIb (C. deuterogattii), ST7. We compared these results with strains previously reported to have been isolated from cats. This comparison suggested that molecular types of Cryptococcus spp. isolated from cats may differ depending on the country. In the antifungal susceptibility testing of C. neoformans, one strain each exceeded the epidemiological cutoff value (ECV) for amphotericin B and 5-fluorocytosine, while two strains exceeded the ECV for fluconazole. This study reveals the molecular epidemiology of Cryptococcus spp. isolated from cats with cryptococcosis in Japan. It suggests that investigating Cryptococcus spp. carried by cats, which share close living environments with humans, may contribute to the health of both cats and human populations.
隐球菌病是人类和猫的一种重要真菌病，但关于从猫中分离的菌株的分子流行病学研究有限。我们对来自日本的 14 株隐球菌和一株来自新加坡猫的隐球菌进行了多位点序列分型分析和抗真菌药敏试验。来自日本的 14 株猫源隐球菌均鉴定为新生隐球菌分子型 VNI。序列型包括 8 株 ST5、5 株 ST31 和 1 株新的 ST。VNI ST5 也是日本患者中最常分离的菌株，而没有记录显示 VNI ST31 从日本患者中分离。新加坡猫株被鉴定为 C. gattii VGIIb（C. deuterogattii），ST7。我们将这些结果与以前报道的从猫中分离的菌株进行了比较。这些比较表明，从猫中分离的隐球菌的分子类型可能因国家而异。在新生隐球菌的抗真菌药敏试验中，有 1 株对两性霉素 B 和 5-氟胞嘧啶的药敏值超过了流行病学截止值（ECV），有 2 株对氟康唑的药敏值超过了 ECV。本研究揭示了日本猫隐球菌病中分离的隐球菌的分子流行病学。它表明，调查与人类密切生活环境的猫所携带的隐球菌可能有助于猫和人类群体的健康。
