Direct Quantification of the Enteric Bacterium Oxalobacter formigenes in Human Fecal Samples by Quantitative Competitive-Template PCR

Homeostasis of oxalic acid appears to be regulated, in part, by the gut-associated bacterium Oxalobacter formigenes. The loss of this bacterium from the gut flora is associated with an increased susceptibility to hyperoxaluria, a condition which can lead to the formation of calcium oxalate crystalluria and kidney stones. In order to identify and quantify the presence of O. formigenes in clinical specimens, a quantitative-PCR-based assay system utilizing a competitive DNA template as an internal standard was developed. This quantitative competitive-template PCR test allows for the rapid, highly specific, and reproducible quantification of O. formigenes in fecal samples and provides a prototype for development of DNA-based quantitative assays for enteric bacteria.

草酸稳态（oxalic acid homeostasis）似乎部分由肠道共生细菌产甲酸草酸杆菌（Oxalobacter formigenes）调控。该菌从肠道菌群（gut flora）中缺失与高草酸尿症（hyperoxaluria）易感性升高相关，该病症可引发草酸钙结晶尿症（calcium oxalate crystalluria）与肾结石（kidney stones）。为实现在临床样本中鉴定并定量产甲酸草酸杆菌的存在，研究人员开发了一种基于定量聚合酶链式反应（quantitative-PCR，qPCR）、以竞争性DNA模板作为内标的检测体系。该定量竞争性模板PCR检测方法可快速、高特异性且可重复地定量粪便样本中产甲酸草酸杆菌的含量，同时为肠道细菌的DNA定量检测方法的开发提供了原型范例。