本研究的目的是在伊朗北部马赞达兰省的HIV + / AIDS和接受化疗的癌症患者的粪便样本中，鉴定腸上皮细胞寄生虫和脑寄生虫属的存在，并将结果与健康个体进行比较。收集了来自伊朗北部医疗中心的50名HIV + / AIDS患者，50名癌症患者和50个健康个体的粪便样本。将粪便样本保存在4°C的2.5%重铬酸钾中，并使用改良的三色染色法进行光学显微镜检查。多重/嵌套PCR针对小亚基核糖核酸（SSU rRNA）基因。为了表征基因型，将嵌套PCR产物进行测序，并进行系统发生学分析。（辅助单位：Bioneer Company） 在50个HIV + / AIDS患者中，有10个样本（20%）镜下阳性，5个癌症患者样本（10%）镜下阳性，健康个体中有1个（2%）镜下阳性。在50个HIV + / AIDS患者中，检测到10例（20%）E. bieneusi和6例（12%）脑寄生虫属感染。此外，在癌症患者中，检测到7例（14%）E. bieneusi和2例（4%）脑寄生虫属感染。在50个健康个体样本中，仅观察到3例（6%）E. bieneusi感染。在阳性样本中检测到了D和M基因型的E. bieneusi。 E. bieneusi和脑寄生虫属是马赞达兰省HIV + / AIDS患者和接受化疗的癌症患者常见的肠道微孢子虫。在马赞达兰省，基因型D似乎是主要的基因型。由于肠道微孢子虫的显著流行，建议医生对高风险群体的这种机会性感染给予更多关注。 © 2023. 作者（研究人员）独家授权给Stefanowski Institute of Parasitology, Polish Academy of Sciences。

The aim of this study was to identify Enterocytozoon bieneusi and Encephalitozoon spp. in fecal samples of HIV + /AIDS and cancer patients undergoing chemotherapy, and comparing the results to healthy individuals in Mazandaran province, north of Iran.Stool samples were collected from 50 HIV + /AIDS patients, 50 cancer patients, and 50 healthy samples referred to medical centers in north of Iran. Stool samples were kept in 2.5% potassium dichromate at 4 °C, and stained by modified trichrome for light microscopy examination. The multiplex/nested-PCR targeted the small subunit ribosomal RNA (SSU rRNA) gene. To characterize genotypes, the nested PCR products sequenced by Bioneer Company and was subjected to phylogenetic analyses.Ten of 50 samples (20%) of HIV + /AIDS patients, 5 of 50 samples (10%) of cancer patients, and 1 of healthy individuals (2%) were microscopically positive. From 50 HIV + / AIDS patients, E. bieneusi and Encephalitozoon spp. were detected in 10 (20%) and 6 (12%) cases, respectively. Furthermore, among cancer patients, 7 (14%) and 2 (4%) cases were E. bieneusi and Encephalitozoon spp., respectively. Out of 50 samples of healthy individuals, only 3 (6%) cases of E. bieneusi were observed. The genotypes D and M were detected among positive samples of E. bieneusi.E. bieneusi and then Encephalitozoon spp. are common intestinal microsporidia in HIV + /AIDS patients and cancer patients undergoing chemotherapy in Mazandaran province. E. bieneusi genotype D seems to be the predominant genotype in Mazandaran province. Due to the considerable prevalence of intestinal microsporidia, physicians are advised to pay more attention to this opportunistic infection in high-risk groups.© 2023. The Author(s) under exclusive licence to Witold Stefański Institute of Parasitology, Polish Academy of Sciences.