Aboul-Ella Hassan, Mosallam Tarek, Samir Ojena, Ali Aisha, Qasim Arwa, Mahmoud Hossam Eldin, Samir Ahmed
Department of Microbiology, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt.
Animal Reproduction Research Institute, Haram, Giza, Egypt.
BMC Microbiol. 2025 May 7;25(1):273. doi: 10.1186/s12866-025-03894-9.
Rhodotorulae are environmentally ubiquitous yeasts that were originally considered non-pathogenic. However, over the last fifty years, Rhodotorula mucilaginosa (R. mucilaginosa) has established itself as an emerging opportunistic pathogen incriminated in several systemic and localized infections in humans and animals. Most of the rhodotorulosis cases were linked directly or indirectly to an immunocompromising event in the affected cases. Nevertheless, recently, a few non-immunocompromised cases were reported. In the current study, performed throughout the period from April/2023 to April/2024, 450 samples were collected from pet animals and investigated for the existence and coexistence of Rhodotorula spp. in different clinically diagnosed infectious cases. 173 (38.5%) samples showed positive direct microscopic slides of different sizes of Gram-positive budding yeast cells, 21 (4.7%). Rhodotorula isolates mixed with other yeasts and/or bacterial pathogens were recovered from nasal passages and ear canal swabs collected from dogs and cats suffering from nasal affection and otitis externa. Laboratory investigations were based on sample collection, microscopic examination, primary isolation and identification, biochemical and post-culturing characterization, antifungal susceptibility testing, VITEK 2 Compact Identification System, DNA extraction, PCR amplification, sequencing, and phylogenetic analysis. Moreover, antifungal susceptibility testing based on the standard broth microdilution test was applied to the recovered Rhodotorula isolates. In conclusion, the present findings spotlighted a prospective insight into the role of the emergence of R. mucilaginosa among pet animals and its possible public health concerns. Clinical trial number: Not Applicable.
红酵母是环境中普遍存在的酵母，最初被认为是非致病性的。然而，在过去的五十年里，粘红酵母已成为一种新兴的机会性病原体，涉及人类和动物的多种全身和局部感染。大多数红酵母病病例直接或间接与受影响病例的免疫功能低下事件有关。尽管如此，最近也报告了一些非免疫功能低下的病例。在本研究中，于2023年4月至2024年4月期间，从宠物动物身上采集了450份样本，并调查了不同临床诊断感染病例中红酵母属的存在和共存情况。173份（38.5%）样本在直接显微镜检查中显示出不同大小的革兰氏阳性芽殖酵母细胞呈阳性，21份（4.7%）。从患有鼻病和外耳道炎的犬猫的鼻道和耳道拭子中分离出与其他酵母和/或细菌病原体混合的红酵母分离株。实验室调查基于样本采集、显微镜检查、初次分离和鉴定、生化和培养后特征分析、抗真菌药敏试验、VITEK 2 Compact鉴定系统、DNA提取、PCR扩增、测序和系统发育分析。此外，对分离出的红酵母分离株采用基于标准肉汤微量稀释试验的抗真菌药敏试验。总之，本研究结果对粘红酵母在宠物动物中的出现及其可能的公共卫生问题的作用提供了前瞻性见解。临床试验编号：不适用。
