Department of Medical Mycology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
Infectious and Tropical Diseases Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
J Clin Lab Anal. 2022 Sep;36(9):e24664. doi: 10.1002/jcla.24664. Epub 2022 Aug 16.
The most frequent species of Candida to infect and colonize patients with neutropenia is still Candida albicans. This study aimed to provide detailed information on the phenotype, genotype, and mating type of oral C. albicans isolated from neutropenic pediatric patients, and to investigate how these characteristics are related.
Two hundred fifty-four oral samples from patients under 18 years old with neutropenia and malignancies were collected from January to October 2021. Samples were cultured on CHROMagar Candida. Isolates of C. albicans were identified with the germ tube test, chlamydospore production on cornmeal agar, and PCR-RFLP. Genotyping of C. albicans isolates was carried out by amplifying the 25S rDNA gene with specific CAINT-L and CA-INT-R primers. MTLa1 and MTLα1 primers were used to identify each mating type. Yeast peptone dextrose supplemented with phloxine B was used to identify different phenotypes.
Ninety-two (36%) patients were positive for C. albicans. The mean age of patients was 7.85. Fifty-three (58.9%) isolates demonstrated type A, 15 (16.7%) type B, 15 (16.7%) types D/E, and 7 (7.7%) type C. Three isolates each (3.3%) were homozygous for MTLa or homozygous for MTLα. All of the MTL-homozygous isolates were genotype A. There was a significant correlation between patients' underlying disease and genotype (p = 0.036). There was a significant correlation between mating type and genotype (p = 0.000).
Most of the isolates exhibited a white phenotype, noted in the literature as the most virulent. Moreover, heterozygous strains were frequent and may play a role in Candida colonization.
最常感染和定植中性粒细胞减少症患者的念珠菌属物种仍然是白色念珠菌。本研究旨在提供有关从中性粒细胞减少症儿科患者口腔分离的白色念珠菌的表型、基因型和交配型的详细信息，并探讨这些特征之间的关系。
2021 年 1 月至 10 月期间，共采集了 254 名患有中性粒细胞减少症和恶性肿瘤的 18 岁以下患者的口腔样本。样本在 CHROMagar Candida 上培养。通过芽管试验、玉米粉琼脂上的厚垣孢子生成以及 PCR-RFLP 鉴定白色念珠菌的分离株。通过使用特异性 CAINT-L 和 CA-INT-R 引物扩增 25S rDNA 基因对白色念珠菌分离株进行基因分型。使用 MTLa1 和 MTLα1 引物鉴定每个交配型。使用酵母胰蛋白胨葡萄糖补充 phloxine B 来鉴定不同的表型。
92 名（36%）患者的白色念珠菌呈阳性。患者的平均年龄为 7.85 岁。53 株（58.9%）分离株为 A 型，15 株（16.7%）为 B 型，15 株（16.7%）为 D/E 型，7 株（7.7%）为 C 型。每个（3.3%）有 3 个分离株为 MTLa 纯合或 MTLα 纯合。所有 MTL 纯合分离株均为 A 型。患者的基础疾病与基因型之间存在显著相关性（p=0.036）。交配型与基因型之间存在显著相关性（p=0.000）。
大多数分离株表现出白色表型，这在文献中被认为是最具毒力的表型。此外，杂合菌株很常见，可能在念珠菌定植中发挥作用。
