This study aimed to determine the prevalence and abundance of sewage and animal fecal contamination of sediment at seven estuarine locations in Sydney, NSW, Australia. Sediment samples were tested for the occurrence of microbial targets including molecular marker genes of enterococci (ENT), Bacteroides HF183 (HF183), Methanobrevibacter smithii (nifH), human adenovirus (HAdV) and emerging sewage associated marker genes crAssphage (CPQ_056) and Lachnospiraceae (Lachno3) and animal feces-associated marker genes, including avian feces-associated Helicobacter spp. (GFD), canine-feces associated Bacteroides (DogBact), cattle-feces associated (cowM2) and horse feces associated Bacteroides (HoF597). Results from this study showed that urban estuarine sediment can act as a reservoir of fecal indicator bacteria (FIB) and several microbial source tracking (MST) marker genes, including previously unreported Lachno3. The sewage-associated marker gene CPQ_056 was most prevalent, in 63.8% of sediment samples, while the avian associated marker gene GFD had the highest mean abundance. The GFD marker was highly abundant and widely detected in sediment samples from all seven locations compared to the other animal feces-associated marker genes. In all, 31 (44.9%) sediment samples were positive for at least two sewage-associated marker genes. However, the non-quantifiable detection of the HAdV marker gene did not always align with the detection of two or more sewage-associated marker genes. In addition, the most frequent wet weather overflow exposure occurred at locations that did not have a consistent pattern of detection of the sewage-associated marker genes, suggesting sediments may not be a suitable measure of recent sewage contamination. To assist water quality and public health managers better understand past microbial contamination of estuarine sediment, further studies seem justified to explore the role of decay of MST marker genes in sediment. Further work is also needed on the role of resuspension of MST marker genes from sediment during storm events to the water column as a source of contamination for both the GFD and sewage-associated marker genes.

这项研究旨在确定澳大利亚新南威尔士州悉尼市七个河口位置的污水和动物粪便中沉积物的污染程度和丰富度。测试了沉积物样品中微生物靶标的发生情况，包括肠球菌（ENT），细菌拟杆菌HF183（HF183），史密斯甲烷微杆菌（nifH），人腺病毒（HAdV）以及新兴的污水相关标志物基因crAssphage（CPQ_056）和Lachnospiraceae（ Lachno3）和动物粪便相关的标记基因，包括禽粪便相关的幽门螺杆菌。（GFD），与犬粪相关的拟杆菌（DogBact），与牛粪相关的（cowM2）和与马粪相关的拟杆菌属（HoF597）。这项研究的结果表明，城市河口沉积物可以充当粪便指示细菌（FIB）和一些微生物源跟踪（MST）标记基因的库，包括以前未报道的Lachno3。与污水相关的标记基因CPQ_056在沉积物样品中占63.8％的比例最高，而禽类相关的标记基因GFD具有最高的平均丰度。与其他动物粪便相关的标记基因相比，GFD标记高度丰富，并且在所有七个位置的沉积物样品中被广泛检测到。在至少两个与污水相关的标记基因中，共有31个（44.9％）沉积物样品呈阳性。但是，HAdV标记基因的不可量化检测并不总是与两个或多个与污水相关的标记基因的检测相吻合。此外，最频繁的潮湿天气溢流暴露发生在没有以一致的方式检测与污水相关的标记基因的位置，这表明沉积物可能不是近期污水污染的合适测量方法。为了帮助水质和公共卫生管理人员更好地了解过去微生物对河口沉积物的污染，似乎有必要进行进一步的研究来探索MST标记基因在沉积物中的衰减作用。关于MST标记基因在暴风雨过程中从沉积物到水柱的再悬浮的作用还需要做进一步的工作，作为GFD和与污水相关的标记基因的污染源。这表明沉积物可能不是近期污水污染的合适测量方法。为了帮助水质和公共卫生管理人员更好地了解过去微生物对河口沉积物的污染，似乎有必要进行进一步的研究来探索MST标记基因在沉积物中的衰减作用。关于MST标记基因在暴风雨过程中从沉积物到水柱的再悬浮的作用还需要做进一步的工作，作为GFD和与污水相关的标记基因的污染源。这表明沉积物可能不是近期污水污染的合适测量方法。为了帮助水质和公共卫生管理人员更好地了解过去微生物对河口沉积物的污染，似乎有必要进行进一步的研究来探索MST标记基因在沉积物中的衰减作用。关于MST标记基因在暴风雨过程中从沉积物到水柱的再悬浮的作用还需要做进一步的工作，作为GFD和与污水相关的标记基因的污染源。