ABSTRACTThe harvesting of rainwater is gaining acceptance among many governmental authorities in countries such as Australia, Germany, and South Africa, among others. However, conflicting reports on the microbial quality of harvested rainwater have been published. To monitor the presence of potential pathogenic bacteria during high-rainfall periods, rainwater from 29 rainwater tanks was sampled on four occasions (during June and August 2012) in a sustainable housing project in Kleinmond, South Africa. This resulted in the collection of 116 harvested rainwater samples in total throughout the sampling period. The identities of the dominant, indigenous, presumptive pathogenic isolates obtained from the rainwater samples throughout the sampling period were confirmed through universal 16S rRNA PCR, and the results revealed thatPseudomonas(19% of samples) was the dominant genus isolated, followed byAeromonas(16%),Klebsiella(11%), andEnterobacter(9%). PCR assays employing genus-specific primers also confirmed the presence ofAeromonasspp. (16%),Klebsiellaspp. (47%),Legionellaspp. (73%),Pseudomonasspp. (13%),Salmonellaspp. (6%),Shigellaspp. (27%), andYersiniaspp. (28%) in the harvested rainwater samples. In addition, on one sampling occasion,Giardiaspp. were detected in 25% of the eight tank water samples analyzed. This study highlights the diverse array of pathogenic bacteria that persist in harvested rainwater during high-rainfall periods. The consumption of untreated harvested rainwater could thus pose a potential significant health threat to consumers, especially children and immunocompromised individuals, and it is recommended that harvested rainwater be treated for safe usage as an alternative water source.
College Major Choice and Neighborhood Effects in a Historically Segregated Society: Evidence from South Africa
