Calcification of Bacillary and Streptococcal Variants of Bacterionema matruchotii

Abstract

Two morphologic variants of the calcifiable microorganism Bacterionema matruchotii were examined for calcification after growth in a synthetic medium, and each calcified. The bacillary variant acquired intracellular apatite, whereas the streptococcal variant developed intracellular and extracellular apatite.Bacterionema matruchotii, a filamentous microorganism indigenous to the human mouth, forms intracellular hydroxyapatite.13 Streckfuss and Smith4 reported that the organism dissociated to form unusual, small flat colonies. A subculture of the flat colonies yielded pure cultures of bacillary and streptococcal variants. The purpose of this study was to determine if the morphologic variants retained the calcification potential of the parent organism. Materials and MethodsThe bacillary variant RF7 and the streptococcal variant S, were obtained from B matruchotii, Richardson strain 13; then, they were inoculated lightly into separate 250 ml volumes of a synthetic medium ( Table) in which B matruchotii is known to calcify.5 Actinomyces naeslundii, West Virginia strain 45, was used as a noncalcifying control.All cultures were incubated aerobically at 37 C. The RF7 was grown for seven days. Because of relatively slow growth, S1 was incubated for 14 days. The A naeslundii was examined after 7 and 21 days. In all cultures the medium remained at pH 7.4 + 0.1. The cultures were checked for purity by Gram stain and subcultures grown on appropriate media.The cells were harvested by centrifugation at 27,000 g for five minutes at 5 C and they were water-washed three times. After a check for purity, most of each yield was air-dried at 50 C, ashed* at 55 C for two hours, and analyzed by X-ray diffraction. The remainder was processed and sectioned for electron microscopy. The procedures and instrumentation have been described previously.5 Results Both morphologic variants calcified during cultivation in the synthetic medium. The ashed residues gave X-ray diffraction patterns for apatite (Fig 1). A diffraction pattern obtained with human root dentin is included for comparison.Variant RF7 acquired intracellular apatite. As seen in Figure 2, typical needlelike crystals were distributed singly and in clusters throughout the cytoplasm. Variant S1 developed both intracellular and extracellular apatite (Fig 3). The intracellular deposits usually were grouped near the center of the cell and the extracellular crystals radiated from the periphery. There was no evidence of calcification in the cell wall of either variant.A naeslundii failed to calcify. No crystallinity was detected by X-ray diffraction or by electron microscopy. DiscussionThe morphologic variants RF7 and S. retained the calcification potential of the parent B matruchotii. Each variant formed * Coleman 40 Radio Frequency Asher, Coleman Instruments, Maywood, Ill.

Calcification of oral bacteria: an ultra structural study of two strains of Bacterionema matruchotii

“…This may be due to the presence of structured material, such as the trilaminar vesicles, outside the eell wall proper. ENNEVER et al (1973) have also reported an association of the extracellular crystals with the cell surface. In the ealcifying dental plaque, erystals may appear within the cell walls of some organisins (SCHROEDER 1969), and VAHL, HOHLING, GiJLLENSTERN & WANNENMA-CHER (1964) attributed specific inductive properties to the cell wall components of bacteria.…”

Characteristics of an Induced Variant of Bacterionema matruchotii

“…Spontaneous coccal and bacillary variants described by Streckfuss and Smith5 also have been shown to calcify. 6 The purposes of this study were to determine whether an induced pleomorphic variant of B matruchotii retained the capacity to calcify, and to compare the fermentation profile and ultrastructure of the variant with the parent organism. The variant, a mixture of coccal and bacillary cells, was derived by sonification of B matruchotii.…”

Solubility and Body Fluids

“…calcifications of the dental plaque biofilm, contain various calcium phosphates, since these inorganic ions are provided by saliva or crevicular fluids. Although the pattern of calcification of oral microorganisms, either intra-or extracellularly, is mainly a characteristic of each bacterial species or strain [75], it may be influenced by nutritional factors, such as saliva proteins, as well [76]. The interactions of saliva with dental calculi and its role in preventing dental caries by controlling the enamel de-and remineralisation processes have been reviewed [19].…”