Barbosa Graziela Murta, Colombo Andrea Vieira, Rodrigues Paulo Henrique, Simionato Maria Regina Lorenzetti
Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, São Paulo, Brazil.
PLoS One. 2015 Sep 25;10(9):e0138687. doi: 10.1371/journal.pone.0138687. eCollection 2015.
It is well known that strain and virulence diversity exist within the population structure of Porphyromonas gingivalis. In the present study we investigate intra- and inter-species variability in biofilm formation of Porphyromonas gingivalis and partners Prevotella intermedia and Prevotella nigrescens. All strains tested showed similar hydrophobicity, except for P. gingivalis W83 which has roughly half of the hydrophobicity of P. gingivalis ATCC33277. An intraspecies variability in coaggregation of P. gingivalis with P. intermedia was also found. The association P. gingivalis W83/P. intermedia 17 produced the thickest biofilm and strain 17 was prevalent. In a two-compartment system P. gingivalis W83 stimulates an increase in biomass of strain 17 and the latter did not stimulate the growth of P. gingivalis W83. In addition, P. gingivalis W83 also stimulates the growth of P. intermedia ATCC25611 although strain W83 was prevalent in the association with P. intermedia ATCC25611. P. gingivalis ATCC33277 was prevalent in both associations with P. intermedia and both strains of P. intermedia stimulate the growth of P. gingivalis ATCC33277. FISH images also showed variability in biofilm structure. Thus, the outcome of the association P. gingivalis/P. intermedia seems to be strain-dependent, and both soluble factors and physical contact are relevant. The association P. gingivalis-P. nigrescens ATCC33563 produced larger biomass than each monotypic biofilm, and P. gingivalis was favored in consortia, while no differences were found in the two-compartment system. Therefore, in consortia P. gingivalis-P. nigrescens physical contact seems to favor P. gingivalis growth. The intraspecies variability found in our study suggests strain-dependence in ability of microorganisms to recognize molecules in other bacteria which may further elucidate the dysbiosis event during periodontitis development giving additional explanation for periodontal bacteria, such as P. gingivalis and P. intermedia, among others, to persist and establish chronic infections in the host.
众所周知，牙龈卟啉单胞菌的种群结构中存在菌株和毒力多样性。在本研究中，我们调查了牙龈卟啉单胞菌与中间普氏菌和变黑普氏菌在生物膜形成方面的种内和种间变异性。除牙龈卟啉单胞菌W83外，所有测试菌株均表现出相似的疏水性，牙龈卟啉单胞菌W83的疏水性约为牙龈卟啉单胞菌ATCC33277的一半。还发现牙龈卟啉单胞菌与中间普氏菌共聚集存在种内变异性。牙龈卟啉单胞菌W83/中间普氏菌17组合产生的生物膜最厚，且菌株17占优势。在双室系统中，牙龈卟啉单胞菌W83刺激菌株17生物量增加，而后者不刺激牙龈卟啉单胞菌W83的生长。此外，牙龈卟啉单胞菌W83也刺激中间普氏菌ATCC25611的生长，尽管菌株W83在与中间普氏菌ATCC25611的组合中占优势。牙龈卟啉单胞菌ATCC33277在与中间普氏菌的两种组合中均占优势，且两种中间普氏菌菌株均刺激牙龈卟啉单胞菌ATCC33277的生长。荧光原位杂交图像也显示了生物膜结构的变异性。因此，牙龈卟啉单胞菌/中间普氏菌组合的结果似乎取决于菌株，可溶性因子和物理接触都很重要。牙龈卟啉单胞菌-变黑普氏菌ATCC33563组合产生的生物量比每种单型生物膜都大，在联合体中牙龈卟啉单胞菌占优势，而在双室系统中未发现差异。因此，在牙龈卟啉单胞菌-变黑普氏菌联合体中，物理接触似乎有利于牙龈卟啉单胞菌的生长。我们研究中发现的种内变异性表明，微生物识别其他细菌中分子的能力存在菌株依赖性，这可能进一步阐明牙周炎发展过程中的生态失调事件，为牙龈卟啉单胞菌和中间普氏菌等牙周细菌在宿主体内持续存在并建立慢性感染提供额外解释。
