Identifying human sewage contamination via microbial source tracking (MST) marker genes has proven useful for effective water quality management worldwide; however, performance evaluations for these genes in tropical areas are limited. Therefore, this research assessed four human-associated MST marker genes in aquatic environments of Central Thailand: human polyomaviruses (JC and BK viruses [HPyVs]), bacteriophage crAssphage (CPQ_056), Lachnospiraceae Lachno3, and Bacteroides BacV6-21. HPyV and crAssphage assays were highly sensitive and specific to sewage (n = 19), with no cross-detection in 120 swine, cattle, chicken, duck, goat, sheep, and buffalo composite fecal samples. Lachno3 and BacV6-21 demonstrated high sensitivity but moderate specificity; however, using both markers could improve specificity to >0.80 (max value of 1.00). The most abundant markers in sewage were Lachno3 and BacV6-21 (5.42-8.02 and non-detected-8.05 log10 copies/100 mL), crAssphage (5.28-7.38 log10 copies/100 mL), and HPyVs (3.66-6.53 log10 copies/100 mL), respectively. HPyVs showed higher levels (up to 4.33 log10 copies/100 mL) and higher detection rates (92.7%) in two coastal beaches (n = 41) than crAssphage (up to 3.51 log10 copies/100 mL and 56.1%). HPyVs were also found at slightly lower levels (up to 5.10 log10 copies/100 mL), but at higher detection rates (92.6%), in a freshwater canal (n = 27) than crAssphage (up to 5.21 log10 copies/100 mL and 88.9%). Overall, both HPyVs and crAssphage are suggested as human sewage-associated MST markers in aquatic environments of Central Thailand. This study underlines the importance of characterizing and validating MST markers in host groups and environmental waters before including them in a water quality management toolbox.

中文翻译：

---

与人类废水相关的病毒标记物在热带环境中的性能优于细菌标记物

事实证明，通过微生物来源跟踪（MST）标记基因识别人类污水污染对全球有效的水质管理非常有用；然而，在热带地区对这些基因的性能评估是有限的。因此，这项研究评估了泰国中部水生环境中的四个与人类相关的MST标记基因：人类多瘤病毒（JC和BK病毒[HPyVs]），噬菌体crssphage（CPQ_056），钩毛藻科Lachno3和拟杆菌BacV6-21。HPyV和crAssphage检测对污水高度敏感且特异（n = 19），在120头猪，牛，鸡，鸭，山羊，绵羊和水牛粪便中没有交叉检测。Lachno3和BacV6-21表现出高敏感性但特异性中等。但是，同时使用两种标记物可以将特异性提高到> 0.80（最大值1.00）。污水中最丰富的标记是Lachno3和BacV6-21（5.42-8.02和未检出-8.05 log10拷贝/ 100 mL），卵噬菌体（5.28-7.38 log10拷贝/ 100 mL）和HPyVs（3.66-6.53 log10拷贝/ mL） 100毫升）。与沿岸噬菌体相比，HPyVs在两个沿海海滩（n = 41）中显示出更高的水平（最高4.33 log10份/ 100 mL和56.1％）和更高的检出率（92.7％）。在淡水运河（n = 27）中，HPyVs的水平也略低（最高为5.10 log10拷贝/ 100 mL，但检出率（92.6％）更高（最高为5.21 log10拷贝/ 100 mL和）。 88.9％）。总体而言，在泰国中部水生环境中，HPyV和crasphage均被认为是与人类污水相关的MST标记。