Studies using culture dependent methods have indicated that enterococci, the fecal indicator used to monitor marine waters for the potential of enteric disease risk to swimmers, can be abundant in beach sands and may contribute to water column indicator exceedances. A quantitative PCR (qPCR) method for the Enterococcus genus was tested and applied to more rapidly determine the amount of enterococci in beach sands and study their distribution over space and time. The qPCR method amplified a 23S rDNA sequence specific to Enterococcus (Ludwig and Schliefer, 2000), and was used to examine subsamples and composite samples of wet and dry beach sand from Avalon Bay, CA. The differences in efficiency of DNA recovery and inhibition in qPCR reactions were accounted for by spiking pairs of duplicate subsamples with a known amount of pGEM plasmid before or after extraction, respectively (Coyne et al. 2005). This study revealed levels of environmental inhibition that were similar in wet and dry sands, and efficiency of DNA recovery that was observably lower for wet beach sands and varied between years. Using the correction factors generated by this method to estimate the abundance of Enterococcus, we show that wet and dry beach sands both have Enterococcus spp. populations that can vary dramatically from day to day, and often are potentially higher than the equivalent health standards mandated for recreational waters.

中文翻译：

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使用外源质粒标准和定量 PCR 监测肠球菌属的时空分布。在沙滩上。

使用培养依赖方法的研究表明，肠球菌是用于监测海水对游泳者潜在肠道疾病风险的粪便指标，它可能在沙滩沙中大量存在，并可能导致水柱指标超标。对肠球菌属的定量 PCR (qPCR) 方法进行了测试并应用于更快速地确定沙滩沙中肠球菌的数量并研究它们在空间和时间上的分布。qPCR 方法扩增了特定于肠球菌的 23S rDNA 序列（Ludwig 和 Schliefer，2000），并用于检查来自加利福尼亚州阿瓦隆湾的湿沙滩和干沙滩的子样本和复合样本。qPCR 反应中 DNA 回收效率和抑制效率的差异是通过在提取之前或之后分别用已知量的 pGEM 质粒掺入双份子样品对来解释的（Coyne 等人，2005 年）。这项研究揭示了湿沙滩和干沙滩的环境抑制水平相似，而湿沙滩的 DNA 回收效率明显较低，而且年份不同。使用这种方法产生的校正因子来估计肠球菌的丰度，我们表明湿沙滩和干沙滩都含有肠球菌。每天都可能发生巨大变化，并且通常可能高于休闲水域规定的等效健康标准。这项研究揭示了湿沙滩和干沙滩的环境抑制水平相似，而湿沙滩的 DNA 回收效率明显较低，而且年份不同。使用这种方法产生的校正因子来估计肠球菌的丰度，我们表明湿沙滩和干沙滩都含有肠球菌。每天都可能发生巨大变化，并且通常可能高于休闲水域规定的等效健康标准。这项研究揭示了湿沙滩和干沙滩的环境抑制水平相似，而湿沙滩的 DNA 回收效率明显较低，而且年份不同。使用这种方法产生的校正因子来估计肠球菌的丰度，我们表明湿沙滩和干沙滩都含有肠球菌。每天都可能发生巨大变化，并且通常可能高于休闲水域规定的等效健康标准。