Jiang Chuanhao, Lacante Siti Arifah, Mizuno Tetsushi, Syafruddin Din, Tokoro Masaharu
Department of Global Infectious Diseases, Graduate School of Advanced Preventive Medical Sciences, Kanazawa University, 13-1 Takaramachi, Kanazawa, Ishikawa, 920-8640, Japan.
Graduate School of Hasanuddin University, Jl. Perintis Kemerdekaan Km.10, Makassar, Sulawesi Selatan, Indonesia.
Trop Med Health. 2025 Mar 27;53(1):40. doi: 10.1186/s41182-025-00725-5.
The genus Chilomastix, including C. mesnili, consists of protozoa that parasitize the gastrointestinal tracts of various host organisms, including mammals (humans and non-human primates [NHP]), birds, and amphibians. Despite its widespread presence, Chilomastix spp. are generally considered non-pathogenic, which has led to limited molecular epidemiological studies on this genus. Consequently, genetic reference data for this genus remain scarce in GenBank. In this study, we aimed to establish a molecular classification for Chilomastix spp. by investigating the genetic diversity of isolates from humans and animals in a parasite-endemic region of Indonesia.
A cross-sectional molecular investigation was conducted in Wainyapu Village, Sumba Island, Indonesia. Stool samples were collected annually from 2013 to 2016 and screened using polymerase chain reaction (PCR) targeting the 18S small subunit ribosomal RNA gene (18S rRNA) of Chilomastix spp., followed by direct and subcloning sequencing. Genetic haplotypes of the partial 18S rRNA sequence (1386-1953 bp) from humans (n = 25), dogs (n = 1), pigs (n = 23), rats (n = 38), water buffaloes (n = 3), chickens (n = 10), and ducks (n = 1) were analyzed alongside reference sequences from humans, guinea pigs, leeches, frogs, and water sources using phylogenetic analyses.
The prevalence of Chilomastix spp. was 7.0% (25/356) in humans and 19.7% (75/380) in animals. Phylogenetic analyses revealed the following monophyletic clusters as subtypes (STs): C. mesnili ST1 (human-NHP genotype), C. mesnili ST2-1 (human genotype), and C. mesnili ST2-2 (pig genotype). In addition, C. gallinarum-like haplotypes (chicken genotype) and C. bettencourti-like haplotypes, including ST1 (rat genotype) and ST2 (rat-buffalo genotype), were also identified.
The genetic references registered in this study, along with the revealed molecular classification of Chilomastix spp., are crucial for understanding the genetic diversity and host-specific dynamics of these parasites in endemic regions.
唇鞭毛虫属，包括梅氏唇鞭毛虫，由寄生于各种宿主生物体胃肠道的原生动物组成，这些宿主包括哺乳动物（人类和非人类灵长类动物[NHP]）、鸟类和两栖动物。尽管唇鞭毛虫属广泛存在，但一般认为其不具有致病性，这导致对该属的分子流行病学研究有限。因此，该属的基因参考数据在GenBank中仍然稀缺。在本研究中，我们旨在通过调查印度尼西亚一个寄生虫流行地区人类和动物分离株的遗传多样性，为唇鞭毛虫属建立分子分类。
在印度尼西亚松巴岛的瓦尼亚普村进行了一项横断面分子调查。于2013年至2016年每年收集粪便样本，并使用针对唇鞭毛虫属18S小亚基核糖体RNA基因（18S rRNA）的聚合酶链反应（PCR）进行筛查，随后进行直接测序和亚克隆测序。对来自人类（n = 25）、狗（n = 1）、猪（n = 23）、大鼠（n = 38）、水牛（n = 3）、鸡（n = 10）和鸭（n = 1）的部分18S rRNA序列（1386 - 1953 bp）的遗传单倍型，与来自人类、豚鼠、水蛭、青蛙和水源的参考序列一起进行系统发育分析。
唇鞭毛虫属在人类中的患病率为7.0%（25/356），在动物中的患病率为19.7%（75/380）。系统发育分析揭示了以下单系聚类作为亚型（STs）：梅氏唇鞭毛虫ST1（人类 - NHP基因型）、梅氏唇鞭毛虫ST2 - 1（人类基因型）和梅氏唇鞭毛虫ST2 - 2（猪基因型）。此外，还鉴定出了鸡样单倍型（鸡基因型）和贝氏唇鞭毛虫样单倍型，包括ST1（大鼠基因型）和ST2（大鼠 - 水牛基因型）。
本研究中登记的基因参考数据，以及所揭示的唇鞭毛虫属分子分类，对于理解这些寄生虫在流行地区的遗传多样性和宿主特异性动态至关重要。
