Palmer Robert J, Shah Nehal, Valm Alex, Paster Bruce, Dewhirst Floyd, Inui Taichi, Cisar John O
National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland, USA
National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland, USA.
Appl Environ Microbiol. 2017 May 17;83(11). doi: 10.1128/AEM.00407-17. Print 2017 Jun 1.
Specific interbacterial adhesion, termed coaggregation, is well established for three early colonizers of the plaque biofilm: streptococci, actinomyces, and veillonellae. However, little is known about interactions of other early colonizers and about the extent of interactions within the bacterial community from a single host. To address these gaps, subject-specific culture collections from two individuals were established using an intraoral biofilm retrieval device. Molecular taxonomy (Human Oral Microbe Identification Microarray [HOMIM]) analysis of biofilm samples confirmed the integrity and completeness of the collections. HOMIM analysis verified the isolation of and from only one subject, as well as isolation of a previously uncultivated streptococcal phylotype from the other subject. Strains representative of clonal diversity within each collection were further characterized. Greater than 70% of these streptococcal strains from each subject coaggregated with at least one other coisolate. One-third of the strains carry a known coaggregation mediator: receptor polysaccharide (RPS). Almost all nonstreptococcal isolates coaggregated with other coisolates. Importantly, certain strains demonstrated more coaggregations with their coisolated bacteria than did any or strain, and certain isolates participated in twice as many. Confocal microscopy of undisturbed biofilms showed that and each occur in small multispecies microcolonies. However, in confluent high-biomass regions, occurred in islands whereas was distributed throughout. Together, the data demonstrate that coaggregation networks within an individual's oral microflora are extensive and that and can be important initiators of cell-cell interactions in the early biofilm. Extensive involvement of specific interbacterial adhesion in dental plaque biofilm formation has been postulated based on coaggregation between oral bacteria from culture collections that are not subject specific. In the present study, subject-specific culture collections were obtained from early plaque biofilm of two volunteers, and coaggregations within each culture collection were assayed. Coaggregations, several of which involved a coaggregation-mediating cell surface molecule known from well-studied streptococci, were widespread. Unexpectedly, the little-studied organisms and participated in the greatest numbers of interactions with community members; these two organisms showed different distributions within the undisturbed biofilm. The data show that coaggregation networks encompass most organisms within the biofilm community of each individual, and they indicate prominent participation of organisms such as and in early plaque biofilm formation.
特定的细菌间黏附，即共聚集，在菌斑生物膜的三种早期定植菌中已得到充分证实：链球菌、放线菌和韦荣球菌。然而，对于其他早期定植菌之间的相互作用以及来自单个宿主的细菌群落内部相互作用的程度，我们知之甚少。为了填补这些空白，使用口腔生物膜取回装置建立了来自两名个体的受试者特异性培养物库。对生物膜样本进行的分子分类学（人类口腔微生物鉴定微阵列 [HOMIM]）分析证实了培养物库的完整性和完整性。HOMIM分析证实仅从一名受试者中分离出了[具体菌种1]和[具体菌种2]，以及从另一名受试者中分离出了一种先前未培养的链球菌系统型。对每个培养物库中代表克隆多样性的菌株进行了进一步表征。来自每个受试者的这些链球菌菌株中，超过70%与至少一种其他共分离菌株发生了共聚集。三分之一的菌株携带一种已知的共聚集介质：受体多糖（RPS）。几乎所有非链球菌分离株都与其他共分离菌株发生了共聚集。重要的是，某些[具体菌种3]菌株与其共分离细菌的共聚集次数比任何[具体菌种1]或[具体菌种2]菌株都多，并且某些[具体菌种4]分离株参与的共聚集次数是其两倍。对未受干扰的生物膜进行的共聚焦显微镜观察表明，[具体菌种1]和[具体菌种2]各自存在于小型多菌种微菌落中。然而，在融合的高生物量区域，[具体菌种1]呈岛屿状分布，而[具体菌种2]则分布于整个区域。总之，这些数据表明个体口腔微生物群中的共聚集网络广泛，并且[具体菌种1]和[具体菌种2]可能是早期生物膜中细胞间相互作用的重要引发者。基于来自非受试者特异性培养物库的口腔细菌之间的[具体菌种1]共聚集现象，有人推测特定细菌间黏附在牙菌斑生物膜形成中广泛存在。在本研究中，从两名志愿者的早期菌斑生物膜中获得了受试者特异性培养物库，并对每个培养物库中的共聚集情况进行了检测。共聚集现象广泛存在，其中一些涉及从经过充分研究的链球菌中已知的共聚集介导细胞表面分子。出乎意料的是，研究较少的[具体菌种3]和[具体菌种4]与群落成员的相互作用次数最多；这两种生物在未受干扰的生物膜中表现出不同的分布。数据表明共聚集网络涵盖了每个个体生物膜群落中的大多数生物，并且它们表明[具体菌种3]和[具体菌种4]等生物在早期菌斑生物膜形成中发挥着重要作用。
