Mwirigi Liza Kiende, Mbae Cecilia, Muturi Margaret, Mathenge Scholastica, Mugo Michael, Irungu Tabitha, Ngugi Benjamin, Mulinge Erastus
Department of Medical Laboratory Science, Kenyatta University, P.O Box 43844-00100, Nairobi, Kenya.
Centre for Microbiology Research, Kenya Medical Research Institute, P.O Box 19464-00202, Nairobi, Kenya.
Food Waterborne Parasitol. 2025 May 11;39:e00268. doi: 10.1016/j.fawpar.2025.e00268. eCollection 2025 Jun.
Enteric parasitic infections are a leading cause of diarrheal disease and malnutrition in low- and middle-income countries like Kenya. Among the most prevalent protozoan pathogens in children are and species. However, data on their genetic diversity, co-occurrence, and variability in Kenya remain limited. This study investigated the genetic diversity of spp. and spp. in children aged 10 years and below in Kiambu County, Kenya. A total of 550 stool samples were analyzed for enteric parasites using formal-ether concentration and Modified Ziehl-Neelsen staining. Genomic DNA was extracted from microscopy-positive samples, and species-specific nested polymerase chain reaction was performed to genotype spp. using the 18S ribosomal RNA gene. For and spp., nested PCR and sequencing targeted the , triose phosphate isomerase, and 60-kDa glycoprotein genes, respectively. Microscopy detected spp. (29.6 %, 163/550), (14.6 %, 80/550), and spp. (1.3 %, 7/550). PCR analysis identified (3.3 %, 18/550), (3.8 %, 21/550), (1.6 %, 9/550), (13.1 %, 72/550), and (1.5 %, 8/550). Sequence analysis of the and genes identified assemblages A (20/50) and B (30/50). All assemblage A isolates were classified as sub-assemblage AII (20/20), while assemblage B isolates were further subdivided into sub-assemblages BIII (21/30) and BIV (9/30). All isolates were identified as , with subtypes IbA9G3 (5/6) and IeA11G3T3 (1/6). Microscopy results revealed a significant association between spp. and spp. with both age groups and study sites. by PCR and by microscopy showed significant differences between study sites. Additionally, the distribution of assemblages A and B, along with sub-assemblages AII, BIII, and BIV, differed significantly between the study sites. Among these, only sub-assemblage BIV showed a significant association with age groups. The detection of alongside related spp. underscores the importance of molecular diagnostics for accurate amoebiasis management and epidemiological surveillance. Additionally, the identification of sub-assemblages AII, BIII, and BIV, as well as subtypes, suggests anthroponotic transmission, emphasizing the need for improved sanitation and public health interventions.
在肯尼亚等低收入和中等收入国家，肠道寄生虫感染是腹泻病和营养不良的主要原因。在儿童中最普遍的原生动物病原体是贾第虫属和隐孢子虫属物种。然而，关于它们在肯尼亚的遗传多样性、共生情况和变异性的数据仍然有限。本研究调查了肯尼亚基安布县10岁及以下儿童中贾第虫属和隐孢子虫属的遗传多样性。使用甲醛-乙醚浓缩法和改良齐尔-尼尔森染色法对总共550份粪便样本进行肠道寄生虫分析。从显微镜检查呈阳性的样本中提取基因组DNA，并使用18S核糖体RNA基因通过物种特异性巢式聚合酶链反应对贾第虫属进行基因分型。对于隐孢子虫属和微小隐孢子虫属，巢式PCR和测序分别靶向热休克蛋白70、磷酸丙糖异构酶和60 kDa糖蛋白基因。显微镜检查检测到蓝氏贾第鞭毛虫（29.6%，163/550）、微小隐孢子虫（14.6%，80/550）和人隐孢子虫（1.3%，7/550）。PCR分析鉴定出十二指肠贾第虫（3.3%，18/550）、蓝氏贾第鞭毛虫（3.8%，21/550）、人隐孢子虫（1.6%，9/550）、微小隐孢子虫（13.1%，72/550）和贝氏隐孢子虫（1.5%，8/550）。对热休克蛋白70和磷酸丙糖异构酶基因的序列分析鉴定出贾第虫属组合A（20/50）和组合B（30/50）。所有组合A分离株均被归类为亚组合AII（20/20），而组合B分离株进一步细分为亚组合BIII（21/30）和BIV（9/30）。所有隐孢子虫分离株均被鉴定为微小隐孢子虫，亚型为IbA9G3（5/6）和IeA11G3T3（1/6）。显微镜检查结果显示蓝氏贾第鞭毛虫和微小隐孢子虫与年龄组和研究地点之间均存在显著关联。PCR检测的十二指肠贾第虫和显微镜检查的蓝氏贾第鞭毛虫在研究地点之间存在显著差异。此外，贾第虫属组合A和B以及亚组合AII、BIII和BIV的分布在研究地点之间也存在显著差异。其中，只有亚组合BIV与年龄组存在显著关联。蓝氏贾第鞭毛虫与相关隐孢子虫属的检测突出了分子诊断对于准确管理阿米巴病和进行流行病学监测的重要性。此外，贾第虫属亚组合AII、BIII和BIV以及隐孢子虫亚型的鉴定表明存在人传人传播，强调需要改善卫生条件和加强公共卫生干预措施。
