Fernandes Claudia do Cabo, Rechenberg Dan-Krister, Zehnder Matthias, Belibasakis Georgios N
Oral Microbiology and Immunology, Institute of Oral Biology, Center of Dental Medicine, University of Zürich, 8032 Zürich, Switzerland.
Endodontology, Clinic of Preventive Dentistry, Periodontology and Cardiology, Center of Dental Medicine, University of Zürich, Zürich, Switzerland.
Microb Pathog. 2014 Aug;73:1-6. doi: 10.1016/j.micpath.2014.05.001. Epub 2014 May 14.
The bacterial phylum Synergistetes consists of Gram-negative anaerobes. Oral Synergistetes are divided in two main clusters, namely A and B. Increasing evidence demonstrates their involvement in etiology of oral infections, including apical periodontitis. This condition causes bone loss around the apex of the tooth, subsequent to pulp inflammation (pulpitis). Although the presence of Synergistetes has been confirmed in endodontic infections by molecular methods, these have not been morphologically identified in the affected apical region, and their prevalence among different endodontic infections has not been determined. Therefore, the aim of this study was to evaluate the prevalence, levels and morphology of oral Synergistetes clusters A and B, in apical root canal samples obtained of teeth with irreversible pulpitis, pulp necrosis and apical periodontitis, or previously root-filled teeth with apical periodontitis. For their detection, fluorescence in situ hybridization and epifluorescence microscopy were used. Synergistetes cluster A was not detected in pulpitis, but was found in both apical periodontitis groups, more frequently and at higher ranges in teeth which were previously root-filled. Microscopically, they appeared as straight or slightly curved long rods. Synergistetes cluster B was not detected in any of the cases. Fusobacteria and Actinomyces, which are well-established taxa in endodontic infections, were detected more frequently and at higher ranges than Synergistetes. In conclusion, Synergistetes cluster A constitutes part of the mixed apical microbiota in apical periodontitis, and may be involved in its pathogenesis.
互养菌门由革兰氏阴性厌氧菌组成。口腔互养菌分为两个主要类群，即A群和B群。越来越多的证据表明它们参与口腔感染的病因，包括根尖周炎。这种情况会在牙髓炎症（牙髓炎）后导致牙根尖周围骨质流失。尽管通过分子方法已在牙髓感染中证实了互养菌的存在，但尚未在受影响的根尖区域对其进行形态学鉴定，也未确定它们在不同牙髓感染中的患病率。因此，本研究的目的是评估在患有不可逆性牙髓炎、牙髓坏死和根尖周炎的牙齿或先前患有根尖周炎的根管充填牙齿的根尖根管样本中，口腔互养菌A群和B群的患病率、水平和形态。为了进行检测，使用了荧光原位杂交和落射荧光显微镜技术。在牙髓炎中未检测到互养菌A群，但在两个根尖周炎组中均有发现，在先前已进行根管充填的牙齿中更频繁且含量更高。在显微镜下，它们呈现为直的或略弯曲的长杆状。在任何病例中均未检测到互养菌B群。在牙髓感染中已明确的梭杆菌属和放线菌属，比互养菌检测得更频繁且含量更高。总之，互养菌A群是根尖周炎混合根尖微生物群的一部分，可能参与其发病机制。
