Alkali-resistant bacteria in root canal systems.
Alkali-resistant bacteria in root canal systems.
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DOI：
10.1111/j.1399-302x.2004.00174.x
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发表时间：
2004-12
影响因子：
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通讯作者：
K. Nakajo;F. Nakazawa;M. Iwaku;E. Hoshino
中科院分区：
文献类型：
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作者：
K. Nakajo;F. Nakazawa;M. Iwaku;E. Hoshino
本研究的目的是从感染根管的牙本质中分离和鉴定耐碱细菌。将来自受感染的人类牙齿根管壁制成的均质牙本质粉末中的细菌在补充有 4% 羊血（BHI 血琼脂）的富含缓冲液的脑心浸液琼脂上培养，调整至 pH 7.0、9.0 或 10.0。在厌氧手套箱中于37℃培养7天。根据菌落和形态选择的细菌菌株在pH值调整为9.0、10.0或11.0的富含缓冲液的BHI肉汤中传代培养，以确认它们作为耐碱细菌的生长。使用特异性引物组进行聚合酶链式反应扩增并进行 16S rDNA 序列分析以鉴定耐碱分离株。在本研究中，使用了 37 名患者拔出的 37 颗牙齿来制备牙本质粉末样品。使用标准 BHI 血琼脂 (pH 7.0) 时，在 25 个样品中检测到细菌。其中，来自 15 个样品的 29 株菌株具有耐碱性，其中 25 株在 pH 9.0 下生长，4 株在 pH 10.0 下生长。耐碱菌株包括屎肠球菌（10株）、粪肠球菌（2株）、癌性肠杆菌（1株）、具核梭杆菌（1株）、溶鸟克雷伯菌（2株）、鼠李糖乳杆菌（2株）、咽峡炎链球菌（2株）。 菌株）、星座链球菌（3 株）和轻症链球菌（2 株）。三种菌株在属水平上也被鉴定为厚壁菌门或葡萄球菌属细菌。本研究表明，感染根管牙本质中的许多细菌种类在pH 9.0和/或pH 10.0下具有耐碱性，并且主要属于肠球菌属。
The aim of this study was to isolate and identify alkali-resistant bacteria from the dentin of infected root canals. Bacteria from homogenized dentin powder made up from infected root canal walls from human teeth were cultured on buffer-enriched Brain Heart Infusion agar supplemented with 4% sheep blood (BHI-blood agar), adjusted to pH 7.0, 9.0 or 10.0. Incubation took place for 7 days at 37 degrees C in an anaerobic glove box. Bacterial strains selected according to colony and morphology were subcultured in buffer-enriched BHI broth adjusted to pH 9.0, 10.0 or 11.0 to confirm their growth as alkali-resistant bacteria. Polymerase chain reaction amplification using specific primer sets and 16S rDNA sequence analysis was performed for identification of alkali-resistant isolates. In the present study, 37 teeth extracted from 37 patients were used for preparation of the dentin powder samples. Bacteria were detected in 25 samples when standard BHI-blood agars (pH 7.0) were used. Of these, 29 strains from 15 samples were alkali resistant, 25 strains growing at pH 9.0 and 4 at pH 10.0. The alkali-resistant strains included Enterococcus faecium (10 strains) and Enterococcus faecalis (2 strains), Enterobacter cancerogenus (1 strains), Fusobacterium nucleatum (1 strains), Klebsiella ornithinolytica (2 strains), Lactobacillus rhamnosus (2 strains), Streptococcus anginosus (2 strains), Streptococcus constellatus (3 strains), and Streptococcus mitis (2 strains). Three strains were also identified as bacteria of genus Firmicutes or Staphylococcus at the genus level. The present study showed that many bacterial species in infected root canal dentin were alkali-resistant at pH 9.0 and/or pH 10.0, and belonged mainly to the genus Enterococcus.