Avian and possum fecal droppings may negatively impact roof-harvested rainwater (RHRW) water quality due to the presence of zoonotic pathogens. This study was aimed at evaluating the performance characteristics of a possum feces-associated (PSM) marker by screening 210 fecal and wastewater samples from possums (n ؍ 20) and a range of nonpossum hosts (n ؍ 190) in Southeast Queensland, Australia. The host sensitivity and specificity of the PSM marker were 0.90 and 0.95 (maximum value, 1.00), respectively. The mean concentrations of the GFD marker in possum fecal DNA samples (8.8 ؋ 10 7 gene copies per g of feces) were two orders of magnitude higher than those in the nonpossum fecal DNA samples (5.0 ؋ 10 5 gene copies per g of feces). The host sensitivity, specificity, and concentrations of the avian feces-associated GFD marker were reported in our recent study (
IMPORTANCEThe use of roof-harvested rainwater (RHRW) for domestic purposes is a globally accepted practice. The presence of pathogens in rainwater tanks has been reported by several studies, supporting the necessity for the management of potential health risks. The sources of fecal pollution in rainwater tanks are unknown. However, the application of microbial source tracking (MST) markers has the potential to identify the sources of fecal contamination in a rainwater tank. In this study, we provide evidence of avian and possum fecal contamination in tank water samples using molecular markers. This study established a potential link between the degradation of the microbial quality of tank water and avian and possum feces.
Growing water scarcity has led to the increased reliance on alternative and decentralized potable and nonpotable water resources in recent decades. Australia is the driest inhabited continent on earth and suffered from a severe "millennium" drought from 2001 to 2009 (1). As a result of the water scarcity in this region, the use of roof-harvested rainwater (RHRW) (stored in tanks) for domestic purposes is a widely accepted practice. This is beneficial for simultaneously conserving water and reducing storm water runoff. The presence of multiple microbial pathogens, including opportunistic pathogens in rainwater tanks, has been reported by several studies, supporting the necessity for the management of potential health risks (2-4).Pathogens could be introduced to tanks via roof runoff containing fecal matter from birds, insects, bats, possums, and reptiles. The microbiological quality of RHRW stored in tanks is generally assessed by monitoring Escherichia coli, which is commonly found in the gut of warm-blooded animals (2, 5, 6). The presence of E. coli in tank water generally indicates fecal contamination and the potential for public health risks. Drinking water guidelines have been used to assess the microbial quality of the tank water. For most guidelines, this entails the nondetection of E. coli in 100 ml of water (7,8). Even when tank water is not used for drinking, assessment of the microbial quality is usually undertaken ...