Human enteric viruses in groundwater indicate offshore transport of human sewage to coral reefs of the Upper Florida Keys

Abstract

To address the issue of human sewage reaching corals along the main reef of the Florida Keys, samples were collected from surface water, groundwater and coral [surface mucopolysaccharide layers (SML)] along a 10 km transect near Key Largo, FL. Samples were collected semi-annually between July 2003 and September 2005 and processed for faecal indicator bacteria (faecal coliform bacteria, enterococci and Clostridium perfringens) and human-specific enteric viruses (enterovirus RNA and adenovirus DNA) by (RT)-nested polymerase chain reaction. Faecal indicator bacteria concentrations were generally higher nearshore and in the coral SML. Enteric viruses were evenly distributed across the transect stations. Adenoviruses were detected in 37 of 75 samples collected (49.3%) whereas enteroviruses were only found in 8 of 75 samples (10.7%). Both viruses were detected twice as frequently in coral compared with surface water or groundwater. Offshore, viruses were most likely to be found in groundwater, especially during the wet summer season. These data suggest that polluted groundwater may be moving to the outer reef environment in the Florida Keys.

Human Pathogen Shown to Cause Disease in the Threatened Eklhorn Coral Acropora palmata

“…However, most wastewater in the Keys and wider Caribbean is not treated, but rather is disposed of through in-ground receptacles [35] within porous limestone substrate that permits leakage from these systems into near-shore waters [36]. Human fecal contamination of near-shore and off-shore coral reef environments has been clearly demonstrated in the Florida Keys [35]–[38] and elsewhere in the Caribbean [39] and is associated with waterborne disease in humans [40]. In response, the state of Florida passed legislation to improve water quality in the Florida Keys by requiring the upgrade of all wastewater facilities, including in-ground receptacles, to the best available technology or to advanced wastewater treatment at an estimated cost of $939 million [41].…”

Potential role of viruses in white plague coral disease

“…Previously it has been shown that environmental viruses such as human enteroviruses and adenoviruses are present on coral mucus, suggesting that these associations were the result of anthropogenic pollution (for example, runoff; Lipp et al, 2002Lipp et al, , 2007Futch et al, 2010). Serratia marcescens, a human bacterial pathogen, also found in sewage was demonstrated to be the cause of white pox disease in acroporids; it is likely that other pathogens including viruses originate from sewage and negatively affect corals (Patterson et al, 2002;Sutherland et al, 2011).…”

Detection and Occurrence of Indicator Organisms and Pathogens

“…Another phenotypic MST approach used antibiotic resistance analysis (ARA) in which library was first constructed for of E. coli isolates that were collected over a period of four years from animal feces that are known to pollute the Guiwu reservoir at Xuyu, China (Gu et al 2010 (Futch et al 2010). The maximum faecal coliform counts found were 10 5 CFU per 100 mL in coral, 5.5 CFU per 100 mL in surface water and 3.5 CFU per 100 mL in groundwater.…”