Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Aalborg, Denmark.
J Appl Microbiol. 2009 Sep;107(3):944-53. doi: 10.1111/j.1365-2672.2009.04272.x. Epub 2009 Mar 30.
Micro-organisms and molecular markers for microbial source tracking (MST) in coastal waters are often present at low numbers, and often exhibit significant variability in time and space. In this study, we investigated the uptake, accumulation, and persistence of human associated Enterococcus in the mussel Mytilus edulis.
The human associated molecular markers esp in Enterococcus faecium, and M66 in Enterococcus faecalis were targetted by PCR in seawater and mussel samples from coastal sites affected by sewage contamination. Both native mussels and mussels transplanted from pristine to polluted sites were included. The results showed that the esp and M66 markers were often not detectable in seawater whereas mussels were enriched in the markers. Human associated E. faecalis accumulated rapidly in M. edulis, and reached maximum levels after 4-6 h with concentration 30-300 times greater than in the surrounding seawater. Enterococcus faecalis retained in M. edulis showed a survival comparable to planktonic E. faecalis in seawater with half lives of 30 and 22 h, respectively. Human associated markers remained detectable for 120 h in M. edulis after faecal contamination.
The study demonstrated that native and transplanted M. edulis can accumulate and retain human associated molecular markers relevant for MST.
Mussels should be considered as additional targets in MST studies in coastal waters.
在沿海海域，用于微生物溯源（MST）的微生物和分子标记物通常数量较少，且在时间和空间上存在显著的可变性。在本研究中，我们研究了贻贝（Mytilus edulis）对人源肠球菌的摄取、积累和持久性。
通过 PCR 检测受污水污染的沿海地区海水和贻贝样本中的人源肠球菌相关分子标记物 esp （Enterococcus faecium）和 M66 （Enterococcus faecalis）。本研究包括了本地贻贝和从清洁区移植到污染区的贻贝。结果表明，esp 和 M66 标记物在海水中通常无法检测到，而贻贝中则富集了这些标记物。人源肠球菌 E. faecalis 在贻贝中迅速积累，在 4-6 小时后达到最大值，其浓度比周围海水中高 30-300 倍。在海水中，与浮游态 E. faecalis 相比，滞留在贻贝中的 E. faecalis 具有相似的存活能力，半衰期分别为 30 和 22 小时。在粪便污染后，贻贝中可检测到人源标记物 120 小时。
本研究表明，本地和移植的贻贝可以积累和保留与 MST 相关的人源分子标记物。
贻贝应被视为沿海 MST 研究中的附加目标。
