Transmission electron microscope study of bacterial morphotypes on the anterior dorsal surface of human tongues

Arora, Harjeen K.; Chapman, George B.

doi:10.1002/1097-0185(20000701)259:3<276::aid-ar50>3.0.co;2-l

Cited by 7 publications

(5 citation statements)

References 27 publications

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“…To further examine the ultrastructure of its cell wall, transmission electron microscopy (TEM) of sectioned cells was performed on the L. iners KY and L. plantarum . Since it has been noted that both TEM and Gram-staining are affected by aging [ 28 , 29 ], we used cells in mid-exponential growth phases. TEM images clearly resolved cell envelopes, consisting of the plasma membrane and peptidoglycan (PG) layer ( Figure 1 d,e).…”

Section: Resultsmentioning

confidence: 99%

Is Lactobacillus Gram-Positive? A Case Study of Lactobacillus iners

Kim

Kang

et al. 2020

Microorganisms

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Lactobacillus iners is the most prevalent bacterial species in the human vaginal microbiome, and there have been few reports of its Gram-negative stain appearances despite the fact that the genus Lactobacillus is universally described as Gram-positive. Here, using transmission electron microscopy, we reveal that the thinness of the cell wall (17.39 ± 0.8 nm) gives the Gram-negative stain appearance, which can lead to over-diagnosis of bacterial vaginosis. Moreover, comparative genome analysis identified four genes commonly absent in L. iners genomes that might contribute to this phenotypic difference. We suggest that, along with the several niche-specific attributes identified, this unique feature may contribute to the species’ distinguished capability to thrive as the predominant species in the fluctuating vaginal environment as well.

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Section: Resultsmentioning

confidence: 99%

Is Lactobacillus Gram-Positive? A Case Study of Lactobacillus iners

Kim

Kang

et al. 2020

Microorganisms

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“…The importance of tongue as a potential microbial reservoir has been suggested by some studies. A study of the ultrastructure of the morphotypes of bacteria residing to the tongue's surface showed the presence of 35 different bacterial morphotyes 1 . Tanner, et al 25 , by using checkerboard DNA probe assay, verified that some cariogenic or periodontal pathogens microorganisms were more frequently isolated from tongue than tooth samples in children under 18 months, and suggested that the tongue is an important microbial reservoir.…”

Section: Introductionmentioning

confidence: 99%

Enterobacteriaceae and pseudomonadaceae on the dorsum of the human tongue

et al. 2009

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Objective:The aim of this study was to correlate the presence of Enterobacteriaceae, Pseudomonadaceae, Moraxellaceae and Xanthomonadaceae on the posterior dorsum of the human tongue with the presence of tongue coating, gender, age, smoking habit and denture use.Material and Methods:Bacteria were isolated from the posterior tongue dorsum of 100 individuals in MacConkey agar medium and were identified by the API 20E system (Biolab-Mérieux).Results:43% of the individuals, presented the target microorganisms on the tongue dorsum, with greater prevalence among individuals between 40 and 50 years of age (p = 0.001) and non-smokers (p=0.0485).Conclusions:A higher prevalence of Enterobacteriaceae and Pseudomonadaceae was observed on the tongue dorsum of the individuals evaluated. There was no correlation between these species and the presence and thickness of tongue coating, gender and presence of dentures.

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“…Importantly, binary fission was visible in both P. gingivalis and P. pallens (red arrow, Figures 2B–D ). In P. pallens ( Figure 2B ), some round bright vacuoles (blue arrows) were abundant, which are electron-lucent granules ( 24 ) The term “electron-lucent” refers to their appearance in the TEM image as loose lighter contrast aggregates. These vacuoles might be rich in lipids or other substances that do not provide significant image contrast ( 25 ).…”

Section: Resultsmentioning

confidence: 99%

Stannous fluoride forms aggregates between outer and inner membranes leading to membrane rupture of Porphyromonas gingivalis and Prevotella pallens

Xie,

Iberi,

Boissy

et al. 2024

Front. Oral. Health

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ObjectiveStannous has been shown to bind to free lipopolysaccharides, thus preventing them from binding to TLR receptors. This study was undertaken to determine the histomorphological mechanism of stannous binding to anaerobic bacteria.MethodsTwo bacteria associated with gingivitis and advanced periodontal disease, Porphyromonas gingivalis (P. gingivalis) and Prevotella pallens (P. pallens), were cultured in 25–1,000 μM of stannous fluoride and stannous chloride for 48 h. The growth rate was estimated using absorbance OD600. Bacterial cells were then fixed and processed for transmission electron microscopy (TEM) analysis.ResultsStannous fluoride inhibited proliferation of both P. gingivalis and P. pallens in a dose-dependent manner. There was a statistically significant suppression of the growth curve starting at 100 μM for P. pallens (P = 0.050) and 200 μM for P. gingivalis (P = 0.039). TEM analysis revealed a thick layer of polysaccharides (19.8 nm) in P. gingivalis. The outer and inner membranes were clearly visible with low electron densities in both bacteria. Stannous diffused into bacterial membranes and formed precipitates in the areas spanning outer and inner membranes and below inner membranes. Precipitates varied in size ranging from 46.4 to 84.5 nm in length, and 18.4 to 35.9 nm in width. The membranes were disintegrated in the region where stannous formed precipitates. Cytosolic contents were leaked out, and in several cases, small vesicles were formed. Stannous precipitates were more abundant in numbers and larger in size in bacteria treated with high concentrations (100–300 μM) than in low concentrations (25–50 μM) of stannous fluoride. Furthermore, most of the bacteria were disintegrated in the groups treated with 100–300 μM stannous fluoride. At low concentrations (25 μM), stannous fluoride formed complexes primarily around outer membranes, to which lipopolysaccharides are anchored. Stannous chloride results showed similar trends, but it was less potent than stannous fluoride.ConclusionStannous fluoride can penetrate bacteria, bind to the constituents of the membrane and form precipitates between outer and inner membranes and beneath inner membranes. These large precipitates damaged the integrity of membranes and allowed cytosolic contents to be leaked out. Stannous complexes formed at the outer membranes, even at low concentrations (25 μM).

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Transmission electron microscope study of bacterial morphotypes on the anterior dorsal surface of human tongues

Cited by 7 publications

References 27 publications

Is Lactobacillus Gram-Positive? A Case Study of Lactobacillus iners

Is Lactobacillus Gram-Positive? A Case Study of Lactobacillus iners

Enterobacteriaceae and pseudomonadaceae on the dorsum of the human tongue

Stannous fluoride forms aggregates between outer and inner membranes leading to membrane rupture of Porphyromonas gingivalis and Prevotella pallens

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