Quantification is generally via comparison
to a standard curve, which is run concurrently with samples using reference material consisting of pre-enumerated cells or DNA. Beach water quality monitoring currently employs culture-based methods to measure fecal indicator bacteria. These methods require 24 h Selleck Rapamycin for sample processing, which is too slow to provide warning against water-borne pathogens, with the majority of contamination events dissipating by the time results become available. In a case study of California beach water quality (Griffith and Weisberg, 2011), qPCR (quantitative PCR) methods are used to reduce the sample processing time to 2 h. A pilot study was conducted in 2010 led by the Southern California Coastal Water Research Project. Three public agencies that perform routine microbiological monitoring of marine waters using traditional growth-based
methods (Orange County Sanitation District, Orange County Public Pexidartinib ic50 Health Laboratory, South Orange County Wastewater Authority) performed the rapid qPCR measurement method for Enterococcus for an 8-week period at 9 beaches. Samples were collected at 8:00 am each morning and returned to the lab for processing. Results were provided to beach managers by 11:00 on average. Public notification of water quality advisories was relayed to beach-goers by noon via electronic signs at the beach, the County Health Department website and Twitter. The rapid method for qPCR as
implemented in the pilot study was approximately 3 times the cost of traditional methods. Higher costs included both labor and assay materials. Additional labor was required for dedicated samplers to bring water samples to the laboratory sooner than they would have arrived under usual circumstances. Supplies to conduct the qPCR analysis were approximately $35 vs. about $12 for the traditional method. The cost of supplies is expected to drop as reagents are produced MRIP on a commercial scale, but additional labor to return samples to the lab in a timely manner will still be required if answers are expected in time to warn potential swimmers of poor water quality before they enter the water. The qPCR method can be performed in about 1.5 h. The fastest culture method takes 24 h. In terms of protecting public health from poor water quality, the rapid qPCR method far surpasses growth-based methods. This method is highly amenable to new indicators and has already been adapted to host associated fecal markers. Implementation of this methodology is a priority in many locals where beach tourism drives the economy. Managers and swimmers want to know when health risks to swimmers are elevated. The primary limitations to the widespread use of this methodology for producing same-day water quality information are cost and logistics. Although the method produces results in approximately 1.