Razavi A, Gmür R, Imfeld T, Zehnder M
Department of Preventive Dentistry, Periodontology and Cariology, University of Zürich Center for Dental Medicine, Zürich, Switzerland.
Oral Microbiol Immunol. 2007 Aug;22(4):248-51. doi: 10.1111/j.1399-302X.2006.00349.x.
Enterococci are rarely found in the healthy human oral cavity, yet they are strongly associated with filled root canals. The origin of these enterococci remains unknown. Our hypothesis is that they are transient food-born colonizers under healthy conditions. This pilot study reinvestigated the prevalence of enterococci in the oral cavity of healthy volunteers, screened cheese samples for enterococci and investigated colonization of the oral cavity after ingestion of an enterocci-positive cheese.
Concentrated oral rinse samples were collected from a cohort of 50 dental students and proved negative for viable enterococci. Twenty cheese samples were obtained from local supermarkets. Enterococci were cultured and identified using standard methods.
Viable enterococci were detected in one of five specimens of Swiss Tilsiter, three of five samples of French soft cheese, one of five Mozzarella samples and one of five Feta samples. Eight volunteers from the cohort consumed 10 g of a cheese with high Enterococcus faecalis load. Oral rinse samples were collected before and 1, 10 and 100 min after cheese ingestion. One minute after ingestion, a median of 5,480 E. faecalis colony-forming units was recovered from the oral rinse samples. Bacterial counts were reduced after 10 min, had dropped after 100 min to levels that were significantly (P < 0.005) different from the 1-min and 10-min scores and were below the detection limit after 1 week.
These findings suggest that colonization of the healthy oral cavity by enterococci is transitional, but at the same time add weight to our hypothesis that enterococcal root canal infections could be food-borne.
肠球菌在健康人口腔中很少见，但与根管充填密切相关。这些肠球菌的来源尚不清楚。我们的假设是，在健康状况下，它们是短暂的经食物传播的定植菌。这项初步研究重新调查了健康志愿者口腔中肠球菌的患病率，筛查了奶酪样本中的肠球菌，并研究了摄入含肠球菌阳性的奶酪后口腔的定植情况。
从50名牙科学生队列中收集浓缩口腔冲洗样本，结果显示活肠球菌呈阴性。从当地超市获取20份奶酪样本。采用标准方法培养和鉴定肠球菌。
在五份瑞士蒂尔西特奶酪样本中的一份、五份法国软奶酪样本中的三份、五份马苏里拉奶酪样本中的一份以及五份菲达奶酪样本中的一份中检测到活肠球菌。该队列中的八名志愿者食用了10克粪肠球菌载量高的奶酪。在食用奶酪前以及食用后1、10和100分钟收集口腔冲洗样本。食用后1分钟，从口腔冲洗样本中回收的粪肠球菌菌落形成单位中位数为5480个。10分钟后细菌计数减少，100分钟后降至与1分钟和10分钟时的分数有显著差异（P < 0.005）的水平，1周后低于检测限。
这些发现表明，肠球菌在健康口腔中的定植是短暂的，但同时也支持了我们关于肠球菌根管感染可能是经食物传播的假设。
