Department of Zoology, Faculty of Science, University of Peradeniya, Peradeniya, Sri Lanka.
Department of Veterinary Pathobiology, Faculty of Veterinary Medicine and Animal Science, University of Peradeniya, Peradeniya, Sri Lanka.
Acta Parasitol. 2024 Jun;69(2):1097-1106. doi: 10.1007/s11686-024-00829-8. Epub 2024 Mar 21.
Soil-transmitted nematodes (STNs) are widespread in tropical and subtropical regions, particularly where the communities are socio-economically challenged. We investigated the effect of soil temperature on the prevalence and intensity of STN infection in free-roaming dogs.
Fresh faecal samples collected from free-roaming dogs in Digana and Pussellawa town areas in the Kandy District, Sri Lanka, were microscopically analysed for canine STNs. Soil temperature was measured at each sampling site. Highly prevalent canine hookworm Ancylostoma, was further studied using PCR and sequencing, followed by phylogenetic analysis.
The soil temperature ranged between 28 and 31 °C (mean = 29.79 °C) and 18-21 °C (mean = 19.52 °C) in Digana and Pussellawa, respectively, showing a significant difference in the two sites (Students t-test t = 1.68, p < 0.0001). Of the total 44 dogs sampled, 41 (93.2%) were positive for STNs. During microscopic analysis, five nematodes: Ancylostoma spp., Capillaria sp., Strongyloides sp., Toxocara canis, and Trichuris sp., were identified. Ancylostoma species (93.2%) were the most prevalent, followed by Strongyloides sp. (22.7%) and Toxocara canis (15.9%). Infection prevalence of Strongyloides sp. was higher in Digana (40.9%) compared to that in Pussellawa (4.5%; Chi-square test, χ = 8.28, p = 0.004) and also the infection intensity from Digana (EPG = 8.02 ± 20.2) compared to that from Pussellawa (0.45 ± 2.1; Mann Whitney U test, p = 0.006). Amplicons (ITS1-5.8S-ITS2) of the expected size for A. caninum, and A. tubaeforme were produced. An A. caninum sequence reported here (OQ101719) illustrated the highest similarity of 99.2% to one of the local sequences (MZ707153) upon pairwise comparison.
Digana, with a higher soil temperature than Pussellawa, had a significantly higher prevalence and infection intensity, particularly Strongyloides sp. This study also signifies the first molecular identification of hookworm species A. tubaeforme in Sri Lanka.
土壤传播的线虫（STNs）在热带和亚热带地区广泛存在，特别是在社会经济面临挑战的地区。本研究旨在调查土壤温度对自由放养犬中土源性线虫感染的流行率和强度的影响。
从斯里兰卡康提区迪加纳和普塞拉瓦镇的自由放养犬中采集新鲜粪便样本，进行犬 STN 的显微镜分析。在每个采样点测量土壤温度。进一步使用 PCR 和测序研究高度流行的犬钩虫Ancylostoma，并进行系统发育分析。
迪加纳的土壤温度范围在 28 到 31°C（平均值为 29.79°C）之间，而普塞拉瓦的土壤温度范围在 18 到 21°C（平均值为 19.52°C）之间，两个地点的土壤温度存在显著差异（学生 t 检验 t=1.68，p<0.0001）。在总共 44 只采样犬中，41 只（93.2%）检测到 STNs 阳性。在显微镜分析中，鉴定出五种线虫：Ancylostoma spp.、Capillaria sp.、Strongyloides sp.、Toxocara canis 和 Trichuris sp.。最常见的线虫是 Ancylostoma 物种（93.2%），其次是 Strongyloides sp.（22.7%）和 Toxocara canis（15.9%）。与普塞拉瓦（4.5%；卡方检验，χ²=8.28，p=0.004）相比，迪加纳的 Strongyloides sp.感染流行率更高（40.9%），与普塞拉瓦相比，迪加纳的感染强度也更高（EPG=8.02±20.2）（Mann-Whitney U 检验，p=0.006）。产生了预期大小为 A. caninum 和 A. tubaeforme 的 ITS1-5.8S-ITS2 扩增子。本研究中报告的 A. caninum 序列（OQ101719）在成对比较时与当地序列（MZ707153）的相似度最高为 99.2%。
迪加纳的土壤温度高于普塞拉瓦，其流行率和感染强度均显著较高，尤其是 Strongyloides sp.。本研究还首次在斯里兰卡鉴定出钩虫物种 A. tubaeforme。
