Walther Carolin, Zumbülte Sandra, Faerber Christoph M, Wierichs Richard Johannes, Meyer-Lueckel Hendrik, Conrads Georg, Henne Karsten, Esteves-Oliveira Marcella
Department of Prosthetic Dentistry, Center for Dental and Oral Medicine, University Medical Center, Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany.
Division of Oral Microbiology and Immunology, Department of Operative Dentistry, Periodontology, and Preventive Dentistry, RWTH Aachen University, Aachen, Germany.
Clin Oral Investig. 2021 Jun;25(6):3669-3679. doi: 10.1007/s00784-020-03691-w. Epub 2020 Nov 23.
Detecting bacterial activity is considered a promising approach to monitor shifts from symbiosis to dysbiosis in oral microbiome. The present study aimed at investigating both the relative bacterial activity and the lactate dehydrogenase (ldh) gene expression of caries-associated bacteria in a site-specific natural biofilm.
Sixty subjects (age, mean ± SE: 30.1 ± 1.4) were allocated to two groups: caries-free subjects (CF) or caries-active subjects (CA). CF presented one sound surface (CFS, n = 30). CA presented two donor sites: a cavitated caries lesion (CAC, n = 30) and a sound reference surface (CAS, n = 30). Real-time quantitative PCR (q-PCR) on species or genus level and total bacteria was performed targeting the 16S gene, the 16S rRNA, the ldh gene, and the ldh mRNA (increasing 16S ribosomal RNA copy numbers can function as an indicator of increased energy metabolism). As the 16S rRNA abundance represents the number of ribosomes, while the 16S gene abundance represents the number of genomes, the quotient of the relative abundances functions as a measure for the relative bacterial activity (%).
Both lactobacilli and S. mutans showed the highest relative bacterial activity in CAC ((mean ± SE) 218 ± 60% and 61 ± 16%, respectively) and the lowest values for both sound reference surfaces (69 ± 48%; 8 ± 3%). Significant differences were found between CAC and CAS as well as between CAC and CFS for both lactobacilli and S. mutans (p < 0.05). The ldh gene expression of lactobacilli and S. mutans only showed moderate values in CAC (1.90E+03 ± 2.11E+03; 2.08E+04 ± 4.44E+04 transcripts/μl) and CFS (2.04E+03 ± 2.74E+03; 8.16E+03 ± 6.64E+03 transcripts/μl); consequently no significant differences were detected.
Caries-associated bacteria (lactobacilli and S. mutans) showed the highest relative bacterial activity in plaque of cavitated lesions, the lowest in sound surfaces, allowing the detection of a significant activity shift in health and disease for caries-active patients. However, no significant differences in ldh gene expression could be determined.
检测细菌活性被认为是监测口腔微生物群落从共生状态向失调状态转变的一种有前景的方法。本研究旨在调查特定部位天然生物膜中与龋齿相关细菌的相对细菌活性和乳酸脱氢酶（ldh）基因表达。
60名受试者（年龄，平均值±标准误：30.1±1.4）被分为两组：无龋受试者（CF）或患龋活跃受试者（CA）。CF组有一个健康表面（CFS，n = 30）。CA组有两个供体部位：一个龋洞病变部位（CAC，n = 30）和一个健康对照表面（CAS，n = 30）。针对16S基因、16S rRNA、ldh基因和ldh mRNA进行物种或属水平以及总细菌的实时定量PCR（q-PCR）（增加16S核糖体RNA拷贝数可作为能量代谢增加的指标）。由于16S rRNA丰度代表核糖体数量，而16S基因丰度代表基因组数量，相对丰度的商用作相对细菌活性（%）的度量。
乳酸杆菌和变形链球菌在CAC部位均表现出最高的相对细菌活性（（平均值±标准误）分别为218±60%和61±16%），在两个健康对照表面的活性最低（69±48%；8±3%）。乳酸杆菌和变形链球菌在CAC与CAS以及CAC与CFS之间均存在显著差异（p < 0.05）。乳酸杆菌和变形链球菌的ldh基因表达在CAC（1.90E + 03±2.11E + 03；2.08E + 04±4.44E + 04转录本/μl）和CFS（2.04E + 03±2.74E + 03；8.16E + 03±6.64E + 03转录本/μl）中仅表现出中等水平；因此未检测到显著差异。
与龋齿相关的细菌（乳酸杆菌和变形链球菌）在龋洞病变菌斑中表现出最高的相对细菌活性，在健康表面最低，这使得能够检测到患龋活跃患者在健康和疾病状态下的显著活性变化。然而，ldh基因表达未发现显著差异。
