Cellular and Molecular Research Center, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran.
Department of Medical Parasitology and Mycology, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran.
Front Cell Infect Microbiol. 2024 Oct 18;14:1477230. doi: 10.3389/fcimb.2024.1477230. eCollection 2024.
Studies have shown that changes in the frequency of oral microorganisms may play a key role in the development of Alzheimer's disease (AD). However, no research has been conducted on the oral fungal composition in AD-patients. The present study aimed to investigate the changes in the frequency of oral fungal composition, the antifungal susceptibility, and the enzymatic profiles of oral fungal composition in patients suffering from AD compared to non-AD individuals.
In the present analytical cross-sectional study during 12 months, 76 hospitalized patients with AD were matched with 76 individuals without AD. A sterile serum physiology-moistened cotton-tipped swab was used to sample the mouth area. All swabs were cultured on Sabouraud Chloramphenicol Agar. Fungal identified were confirmed through the PCR-sequencing techniques. Enzyme activity index (EAI) for important pathogenic factors including proteinase, esterase and hemolysin was measured using relevant protocols. The susceptibility to 8 antifungal agents (nystatin, voriconazole, itraconazole, fluconazole, posaconazole, amphotericin B, 5-fluorocytosine, and caspofungin) against fungal strains obtained from AD-patients was evaluated according to the Clinical and Laboratory Standards Institute (CLSI) guidelines, document M38-A2 for filamentous fungi, and document M27-A4 for yeasts.
The results showed that compared to the non-AD individuals, the prevalence of oral fungal composition in AD group was 1.6 times higher. was the most common fungal species isolated from oral swab samples of AD group (n=53, 80%) and non-AD group (n=28, 40%), and the diversity of the oral fungal composition in AD-patients were lower than non-AD individuals. Among the 3 investigated virulence factors, a statistically significant difference was shown in terms of hemolysin activity level between the two studied groups (<0.05) and the activity level of esterase and proteinase enzymes did not show a significant difference in the two studied groups (>0.05). The results showed that almost all of the tested isolates were susceptible to nystatin, the most widely prescribed antifungal to treat superficial infections, and only 1.69 % (2/118) of the isolates were resistant to this antifungal drug.
Understanding the changes in the frequency of oral fungal composition the antifungal susceptibility, and the enzymatic profiles of oral fungal composition in patients suffering from AD compared to non-AD individuals makes it possible to better understand the etiology of this disease.
研究表明，口腔微生物频率的变化可能在阿尔茨海默病（AD）的发展中起关键作用。然而，目前还没有研究过 AD 患者的口腔真菌组成。本研究旨在调查 AD 患者与非 AD 个体相比，口腔真菌组成的频率变化、抗真菌药物敏感性以及口腔真菌组成的酶谱。
在本研究中，采用 12 个月的分析性横断面研究，将 76 名住院 AD 患者与 76 名非 AD 个体相匹配。使用无菌血清生理湿润的棉签拭子采集口腔区域样本。所有拭子均在沙保罗氯霉素琼脂上培养。通过 PCR 测序技术确认真菌鉴定。使用相关方案测量包括蛋白酶、酯酶和溶血素在内的重要致病因素的酶活性指数（EAI）。根据临床和实验室标准协会（CLSI）指南、丝状真菌的 M38-A2 文件和酵母的 M27-A4 文件，评估从 AD 患者获得的真菌菌株对 8 种抗真菌药物（制霉菌素、伏立康唑、伊曲康唑、氟康唑、泊沙康唑、两性霉素 B、5-氟胞嘧啶和卡泊芬净）的敏感性。
结果表明，与非 AD 个体相比，AD 组的口腔真菌组成患病率高 1.6 倍。是从 AD 组（n=53，80%）和非 AD 组（n=28，40%）口腔拭子样本中分离出的最常见真菌物种，AD 患者的口腔真菌组成多样性低于非 AD 个体。在所研究的 3 种毒力因子中，两组之间溶血素活性水平存在统计学差异（<0.05），而酯酶和蛋白酶酶活性水平在两组之间无显著差异（>0.05）。结果表明，几乎所有测试的分离物对最广泛用于治疗浅表感染的抗真菌药物制霉菌素均敏感，只有 1.69%（2/118）的分离物对该抗真菌药物耐药。
了解 AD 患者与非 AD 个体相比口腔真菌组成的频率变化、抗真菌药物敏感性以及口腔真菌组成的酶谱，可以更好地了解这种疾病的病因。
