&lt;title&gt;Nanobacteria from blood: the smallest culturable autonomously replicating agent on Earth&lt;/title&gt;

Kajander, E. Olavi; Kuronen, Ilpo; Åkerman, Kari; Pelttari, Alpo; Çiftçioğlu, Neva

doi:10.1117/12.278796

Cited by 101 publications

(173 citation statements)

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“…2D) as well as structures resembling divisions occurring simultaneously in vesicular forms (Fig. 2C, arrow), observations that were made earlier with nanobacteria preparations (14). Because CaCO 3 spontaneously precipitates in saturated solutions, the appearance of cellular divisions and budding can be understood as the juxtaposition of aggregating amorphous forms.…”

Section: Calcium Carbonate Nanoparticles Morphologically Similar Tomentioning

confidence: 69%

“…Because CaCO 3 spontaneously precipitates in saturated solutions, the appearance of cellular divisions and budding can be understood as the juxtaposition of aggregating amorphous forms. Although cellular division formations had been used to support the notion that nanobacteria are living cells able to divide (14), these forms can be actually seen here with CaCO 3 nanoparticles prepared in vitro.…”

Section: Calcium Carbonate Nanoparticles Morphologically Similar Tomentioning

confidence: 94%

“…These unusual characteristics actually lead to the suggestions that nanobacteria may represent an overlooked primitive form of life (13) with the smallest cellular dimension known on Earth (14). Similar structures described as ''nannobacteria'' were also reported to abound in calcium carbonate (15) and sulfides sediments (16) where they were seen as overlooked factors affecting geochemical cycles.…”

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confidence: 98%

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Purported nanobacteria in human blood as calcium carbonate nanoparticles

Martel

Young

2008

Proc. Natl. Acad. Sci. U.S.A.

129

155

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Recent evidence suggests a role for nanobacteria in a growing number of human diseases, including renal stone formation, cardiovascular diseases, and cancer. This large body of research studies promotes the view that nanobacteria are not only alive but that they are associated with disease pathogenesis. However, it is still unclear whether they represent novel life forms, overlooked nanometer-size bacteria, or some other primitive self-replicating microorganisms. Here, we report that CaCO 3 precipitates prepared in vitro are remarkably similar to purported nanobacteria in terms of their uniformly sized, membrane-delineated vesicular shapes, with cellular division-like formations and aggregations in the form of colonies. The gradual appearance of nanobacteria-like particles in incubated human serum as well as the changes seen with their size and shape can be influenced and explained by introducing varying levels of CO 2 and NaHCO 3 as well as other conditions known to influence the precipitation of CaCO 3 . Western blotting reveals that the monoclonal antibodies, claimed to be specific for nanobacteria, react in fact with serum albumin. Furthermore, nanobacteria-like particles obtained from human blood are able to withstand high doses of γ-irradiation up to 30 kGy, and no bacterial DNA is found by performing broad-range PCR amplifications. Collectively, our results provide a more plausible abiotic explanation for the unusual properties of purported nanobacteria.

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Section: Calcium Carbonate Nanoparticles Morphologically Similar Tomentioning

confidence: 69%

Section: Calcium Carbonate Nanoparticles Morphologically Similar Tomentioning

confidence: 94%

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confidence: 98%

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Purported nanobacteria in human blood as calcium carbonate nanoparticles

Martel

Young

2008

Proc. Natl. Acad. Sci. U.S.A.

129

155

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“…Nanobacteria possess unusual properties, making their detection difficult with standard microbiological methods. Although they typically had diameters of 0.2-0.5 m, they passed through 0.1-m filters probably because tiny forms (0.05-0.2 m) were also observed in transmission electron microscopy (TEM) (7). Nanobacteria were poorly disruptable, stainable, fixable, and exceptionally resistant to heat (8,9).…”

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confidence: 99%

Nanobacteria: An alternative mechanism for pathogenic intra- and extracellular calcification and stone formation

Çiftçioğlu

1998

Proc. Natl. Acad. Sci. U.S.A.

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442

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Calcium phosphate is deposited in many diseases, but formation mechanisms remain speculative. Nanobacteria are the smallest cell-walled bacteria, only recently discovered in human and cow blood and commercial cell culture serum. In this study, we identified with energydispersive x-ray microanalysis and chemical analysis that all growth phases of nanobacteria produce biogenic apatite on their cell envelope. Fourier transform IR spectroscopy revealed the mineral as carbonate apatite. The biomineralization in cell culture media resulted in biofilms and mineral aggregates closely resembling those found in tissue calcification and kidney stones. In nanobacteria-infected fibroblasts, electron microscopy revealed intra-and extracellular acicular crystal deposits, stainable with von Kossa staining and resembling calcospherules found in pathological calcification. Previous models for stone formation have led to an hypothesis that elevated pH due to urease and͞or alkaline phosphatase activity is a lithogenic factor. Our results indicate that carbonate apatite can be formed without these factors at pH 7.4, at physiological phosphate and calcium concentrations. Nanobacteria can produce apatite in media mimicking tissue f luids and glomerular filtrate and provide a unique model for in vitro studies on calcification.The formation of discrete and organized inorganic crystalline structures within macromolecular extracellular matrices is a widespread biological phenomenon generally referred to as biomineralization. Mammalian bone and dental enamel are examples of biomineralization involving apatite minerals. The molecular basis of mineralization remains largely unknown (1). Recently, bacteria have been implicated as factors in biogeochemical cycles for mineral formation in aqueous sediments (2, 3). The principal constituent of modern authigenic phosphate minerals in marine sediments is carbonate (hydroxy)fluorapatite Ca 10 (PO 4 ) 6-x (CO 3 ) x (F,OH) 2ϩx . Microorganisms are capable of depositing apatite outside thermodynamic equilibrium in sea water. They can segregate Ca from Mg and actively nucleate carbonate apatite by means of specific oligopeptides under conditions pH Ͻ 8.5 and [Mg]:[Ca] Ͼ 0.1 (4). Such conditions are also present in the human body.We have discovered nanobacteria in human and cow blood that are cytotoxic in vitro (5) and in vivo (6). They have been deposited in DSM (no. 5819-5821; Braunschweig, Germany). Nanobacteria possess unusual properties, making their detection difficult with standard microbiological methods. Although they typically had diameters of 0.2-0.5 m, they passed through 0.1-m filters probably because tiny forms (0.05-0.2 m) were also observed in transmission electron microscopy (TEM) (7). Nanobacteria were poorly disruptable, stainable, fixable, and exceptionally resistant to heat (8, 9). Their doubling time was about 3 days. High doses of ␥-irradiation or aminoglycoside antibiotics prevented their multiplication. According to the 16S rRNA gene sequence (EMBL X98418 and X98419), na...

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“…In fact, the lower size limit of fossilized bacteria has not been determined. In mammalian blood, living bacteria as small as 70 nm in diameter have been found which contain identifiable DNA and can reproduce 17,18 . Also, soil bacteria as small as 80 nm have been found 19 .…”

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confidence: 99%