Ultrastructural features of microbial colony organization

Tetz, Victor; Рыбальченко, Оксана Владимировна; Savkova, Galina A.

doi:10.1002/jobm.3620300819

Cited by 24 publications

(25 citation statements)

References 11 publications

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“…Other studies have shown that at later stages of colony development (20 to 24 h), the surface film of E. coli colonies became thicker. On the other hand, the film was not observed for colonies cultured for 6 to 16 h of growth (45)(46)(47)(48). Therefore, it is possible that the glycogen-rich surface layer observed with Raman microspectroscopy is the polysaccharide-rich extracellular coat, commonly known as the glycocalyx, of bacterial cells.…”

Section: Resultsmentioning

confidence: 99%

Investigating Microbial (Micro)colony Heterogeneity by Vibrational Spectroscopy

Choo-Smith

Maquelin

Vreeswijk

et al. 2001

Appl Environ Microbiol

231

160

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Fourier transform infrared and Raman microspectroscopy are currently being developed as new methods for the rapid identification of clinically relevant microorganisms. These methods involve measuring spectra from microcolonies which have been cultured for as little as 6 h, followed by the nonsubjective identification of microorganisms through the use of multivariate statistical analyses. To examine the biological heterogeneity of microorganism growth which is reflected in the spectra, measurements were acquired from various positions within (micro)colonies cultured for 6, 12, and 24 h. The studies reveal that there is little spectral variance in 6-h microcolonies. In contrast, the 12-and 24-h cultures exhibited a significant amount of heterogeneity. Hierarchical cluster analysis of the spectra from the various positions and depths reveals the presence of different layers in the colonies. Further analysis indicates that spectra acquired from the surface of the colonies exhibit higher levels of glycogen than do the deeper layers of the colony. Additionally, the spectra from the deeper layers present with higher RNA levels than the surface layers. Therefore, the 6-h colonies with their limited heterogeneity are more suitable for inclusion in a spectral database to be used for classification purposes. These results also demonstrate that vibrational spectroscopic techniques can be useful tools for studying the nature of colony development and biofilm formation.In recent years, there has been much effort invested into the development of new techniques for the identification of microorganisms. Many of these methods are aimed at providing the clinician with more rapid identification of the microorganism responsible for infection in order to begin the appropriate course of antimicrobial treatment (1,9,15,21,27,31,44,51). The emergence of these novel methods reflects the rise in drug-resistant microorganisms, which requires that antimicrobial treatment be more effectively managed (2, 12, 28, 52). Among the new methods are those based on vibrational spectroscopic techniques, namely Fourier transform infrared (FT-IR) and Raman spectroscopies. Vibrational spectroscopic methods are reagentless procedures in which there is no need to add dyes or labels for spectral measurement. These nondestructive techniques are based on the absorption (FT-IR) or scattering (Raman) of light directed onto a sample. The amount of light absorbed or scattered depends on the molecules found within the sample and the environment in which these molecules are found. With these highly sensitive techniques, the frequency of light in the resulting spectrum provides biochemical information regarding the molecular composition and molecular structure of and molecular interaction in cells and tissues (24,55). Raman and infrared spectroscopies are complementary techniques which together can provide a more complete impression of the biochemical information within a sample. Furthermore, these two methods differ such that each is capable of providing informatio...

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Section: Resultsmentioning

confidence: 99%

Investigating Microbial (Micro)colony Heterogeneity by Vibrational Spectroscopy

Choo-Smith

Maquelin

Vreeswijk

et al. 2001

Appl Environ Microbiol

231

160

View full text Add to dashboard Cite

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“…These contacts contribute to the formation of a three-dimensional system (Tetz et al, 1990a(Tetz et al, , b, 1991Todd et al, 1984). Elements of cell specialization and differentiation in bacterial colonies have also been demonstrated (Tetz et al, 1990b). Bacterial cells exhibit different patterns of genetic expression in different colony zones (Shapiro & Higgins, 1988).…”

Section: Introductionmentioning

confidence: 99%

“…As whole integral systems, bacterial colonies separate themselves from the external environment by a surface film. Recently, we have shown that these surface films have a complex organization and consist of amorphous and membranous layers (Tetz et al, 1990b(Tetz et al, , 1991. The structure of surface colonial films is of great interest because this is a rare example of a single common membrane covering many cells.…”

Section: Introductionmentioning

confidence: 99%

Ultrastructure of the surface film of bacterial colonies

Tetz

Рыбальченко

Savkova

1993

Journal of General Microbiology

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The structure of the surface of colonies of various Gram-negative and Gram-positive bacteria was examined by transmission electron microscopy. The results indicate that bacterial colonies in the course of their development produce a film which becomes thicker with increased duration of growth. The basic part of the film is an elementary membrane, which is a stable structure with a large surface area. The inner and outer surfaces of the film membrane are covered by amorphous layers. These layers are thicker in the surface film of Gram-negative bacterial colonies than in those of Gram-positive bacteria. Membrane vesicles from the bacterial colonies take part in the formation of the surface film. The presence of the film on the surface of the colonies of different bacteria suggests that this structure may play an important role.

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“…The release of vesicles has been demonstrated for both pathogenic and nonpathogenic microbes under a range of growth conditions, including in liquid broth and on agar plates in the laboratory (15,82,90), in biofilms (6,78), upon infection with bacteriophage (50), and by pathogenic organisms growing within an animal host (9,20,23,52,63,88). In addition, modification of medium conditions, such as the presence of serum (62), limitation of essential amino acids (40), or treatment with subinhibitory concentrations of membrane active antibiotics (33), stimulates MV production, suggesting that vesicle release is both dynamic and manipulable, essential characteristics for microbes subjected to ever-changing environments.…”

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confidence: 99%

Membrane Vesicle Release in Bacteria, Eukaryotes, and Archaea: a Conserved yet Underappreciated Aspect of Microbial Life

2012

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ABSTRACTInteraction of microbes with their environment depends on features of the dynamic microbial surface throughout cell growth and division. Surface modifications, whether used to acquire nutrients, defend against other microbes, or resist the pressures of a host immune system, facilitate adaptation to unique surroundings. The release of bioactive membrane vesicles (MVs) from the cell surface is conserved across microbial life, in bacteria, archaea, fungi, and parasites. MV production occurs not onlyin vitrobut alsoin vivoduring infection, underscoring the influence of these surface organelles in microbial physiology and pathogenesis through delivery of enzymes, toxins, communication signals, and antigens recognized by the innate and adaptive immune systems. Derived from a variety of organisms that span kingdoms of life and called by several names (membrane vesicles, outer membrane vesicles [OMVs], exosomes, shedding microvesicles, etc.), the conserved functions and mechanistic strategies of MV release are similar, including the use of ESCRT proteins and ESCRT protein homologues to facilitate these processes in archaea and eukaryotic microbes. Although forms of MV release by different organisms share similar visual, mechanistic, and functional features, there has been little comparison across microbial life. This underappreciated conservation of vesicle release, and the resulting functional impact throughout the tree of life, explored in this review, stresses the importance of vesicle-mediated processes throughout biology.

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Ultrastructural features of microbial colony organization

Cited by 24 publications

References 11 publications

Investigating Microbial (Micro)colony Heterogeneity by Vibrational Spectroscopy

Investigating Microbial (Micro)colony Heterogeneity by Vibrational Spectroscopy

Ultrastructure of the surface film of bacterial colonies

Membrane Vesicle Release in Bacteria, Eukaryotes, and Archaea: a Conserved yet Underappreciated Aspect of Microbial Life

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