Identification of Lactobacilli from Deep Carious Lesions by Means of Species-Specific PCR and MALDI-TOF Mass Spectrometry
Identification of Lactobacilli from Deep Carious Lesions by Means of Species-Specific PCR and MALDI-TOF Mass Spectrometry
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DOI：
10.7754/clin.lab.2013.121225
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发表时间：
2013-01-01
影响因子：
0.7
通讯作者：
Kneist, Susanne
中科院分区：
文献类型：
--
作者：
Callaway, Angelika;Kostrzewa, Markus;Kneist, Susanne
背景资料：本研究的目的是比较MALDI-TOF鉴定87株乳杆菌的结果，这些乳杆菌是从7- 8岁儿童的70个第一磨牙的软或硬龋坏牙本质中分离的，并通过种特异性PCR获得。采用MALDI-TOF MS对87株分离株进行分析（Microflex LT，MALDI Biotyper 3.0，Bruker Daltonik，不莱梅，德国），使用包括> 90个菌种的4110个菌株的参考数据库。为进行种特异性PCR鉴定，设计了L.干酪湖（L. casei）Paracasei，L.类干酪L. rhamnosus，L.加塞里湖plantarum和L.使用嗜酸乳杆菌;模式菌株作为对照。结果：两种方法的结果一致率为93%，其中40株被鉴定为L. rhamnosus，L.拟椰壳亚种paraeasei、L.副干酪亚种tolerans，4个为L. paraeasei，3 as L. gasseri，2个为L. plantarum和L. casei。在4.5%的病例中，结果不一致。在3株未进行种特异性PCR鉴定的菌株中，1株经MALDI-TOF MS鉴定为L. spec.和L. parabuchneri。结论：两种方法均具有较高的敏感性。限制可能是引物（PCR）的精确度或数据库中来自特定栖息地的菌株的稀缺性。对于没有或有不一致鉴定的菌株，需要提供额外信息。
Background: The aim of the present study was to compare MALDI-TOF results for the identification of 87 lactobacilli, isolated from soft or hard carious dentin from 70 first molars of 7- to 8-year-old children with those obtained by species-specific PCR.Methods: The 87 isolates were analyzed by MALDI-TOF MS (Microflex LT, MALDI Biotyper 3.0, Bruker Daltonik, Bremen, Germany), using a reference data base of 4110 strains including > 90 lactobacillus species. For the identification with species-specific PCR, oligonucleotide primers (16S rRNA) specific for L. casei, L. paracasei, L. rhamnosus, L. gasseri, L. plantarum, and L. acidophilus were used; type strains served as controls. The PCR-products were separated electrophoretically on a 1.5% agarose gel and identified by their position on the gel.Results: For 93% of the strains both methods produced concordant results; 40 strains were identified as L. rhamnosus, 16 as L. paraeasei subsp. paraeasei,15 as L. paracasei subsp. tolerans, 4 as L. paraeasei, 3 as L. gasseri, 2 as L. plantarum, and 1 as L. casei. In 4.5% of the cases the results were discordant. Of the 3 strains, not identified by species-specific PCR, 1 strain was identified by MALDI-TOF MS as L. spec. and 1 as L. parabuchneri. One strain could not be identified by either method.Conclusions: Both methods are highly sensitive. Limitations can be the precision of the primers (PCR) or the scarcity of strains from a certain habitat in the data base. Additional information is necessary for the strains without or with discordant identification.