Ultrastructural Study of Chitosan Effects on Klebsiella and Staphylococci

Didenko, L. V.; Gerasimenko, Denis V.; Konstantinova, N. D.; Silkina, T. A.; Avdienko, I. D.; Bannikova, G. E.; Варламов, В. П.

doi:10.1007/s10517-005-0489-6

Cited by 42 publications

(29 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…There was no evidence for cell wall lysis, as described for S. simulans 22 treated with the cationic peptides Pep5 and nisin, which activate cell wall-lytic enzymes from anionic cell wall polymers (4). Our electron microscopic findings thus did not support earlier work, which demonstrated an irregularly structured and frayed cell wall in chitosan-treated microorganisms (28), and even the appearance of protoplasts (10).…”

Section: Vol 74 2008 Antibacterial Mode Of Action Of Chitosan 3767contrasting

confidence: 99%

Insights into the Mode of Action of Chitosan as an Antibacterial Compound

Raafat

Bargen

Haas

et al. 2008

Appl Environ Microbiol

680

323

View full text Add to dashboard Cite

Chitosan is a polysaccharide biopolymer that combines a unique set of versatile physicochemical and biological characteristics which allow for a wide range of applications. Although its antimicrobial activity is well documented, its mode of action has hitherto remained only vaguely defined. In this work we investigated the antimicrobial mode of action of chitosan using a combination of approaches, including in vitro assays, killing kinetics, cellular leakage measurements, membrane potential estimations, and electron microscopy, in addition to transcriptional response analysis. Chitosan, whose antimicrobial activity was influenced by several factors, exhibited a dose-dependent growth-inhibitory effect. A simultaneous permeabilization of the cell membrane to small cellular components, coupled to a significant membrane depolarization, was detected. A concomitant interference with cell wall biosynthesis was not observed. Chitosan treatment of Staphylococcus simulans 22 cells did not give rise to cell wall lysis; the cell membrane also remained intact. Analysis of transcriptional response data revealed that chitosan treatment leads to multiple changes in the expression profiles of Staphylococcus aureus SG511 genes involved in the regulation of stress and autolysis, as well as genes associated with energy metabolism. Finally, a possible mechanism for chitosan's activity is postulated. Although we contend that there might not be a single classical target that would explain chitosan's antimicrobial action, we speculate that binding of chitosan to teichoic acids, coupled with a potential extraction of membrane lipids (predominantly lipoteichoic acid) results in a sequence of events, ultimately leading to bacterial death.

show abstract

Section: Vol 74 2008 Antibacterial Mode Of Action Of Chitosan 3767contrasting

confidence: 99%

Insights into the Mode of Action of Chitosan as an Antibacterial Compound

Raafat

Bargen

Haas

et al. 2008

Appl Environ Microbiol

680

323

View full text Add to dashboard Cite

show abstract

“…Previous studies have reported comparable results using different types of bacteria. According to and Didenko et al (2005) chitosan possesses reactive positively charged amino groups that interact with the bacterial cell membranes, resulting in the leakage of intracellular constituents and alteration of cell permeability, which leads to the microorganism death Je and Kim 2006;Moon et al 2007). The results for tetracycline in solution (T) and in the chitosan gel (CG + T) present the highest diameters for the inhibition zone, around 32 mm.…”

Section: Resultsmentioning

confidence: 99%

Evaluation of Chitosan Gel as Antibiotic and Photosensitizer Delivery

et al. 2008

View full text Add to dashboard Cite

This work suggests the use of chitosan gel imbued with the photosensitizer Photogem and with the antibiotic Tetraclin as a possible drug delivery system. The results reveal a decrease in the photosensitizer level of toxicity. Besides, the interaction between Photogem R and chitosan gel causes a red shift in the photosensitizer spectrum, increasing its absorption in the therapeutic window (600-700 nm). These characteristics indicate this compound as a promising natural polymer-based photosensitizer carrier for photodynamic therapy. In summary, our results show that pure and doped chitosan gel may have potential application for antimicrobial action, being an excellent alternative when local control of the drug administration, provided by the gel, is required.

show abstract

“…This could be due to the detachment of cells from the Earth-plus during the early stages of cell damage. 33,34 Among the three species investigated, the Gram-negative pathogens E. coli and P. aeruginosa were killed more rapidly than the Gram-positive S. aureus pathogens, which could be due to differences in cell structure between Gram-negative and Gram-positive bacteria, 35,36 namely, the increased thickness of the cell wall of Gram-positive bacteria compared with that of Gram-negative bacteria. This could result in a longer period of time required for the Earth-plus to kill the Gram-positive bacteria.…”

Section: Figurementioning

confidence: 99%

Bactericidal activities of woven cotton and nonwoven polypropylene fabrics coated with hydroxyapatite-binding silver/titanium dioxide ceramic nanocomposite "Earth-plus"

Kasuga¹,

Kawakami²,

Matsumoto³

et al. 2011

IJN

View full text Add to dashboard Cite

Background Bacteria from the hospital environment, including linens and curtains, are often responsible for hospital-associated infections. The aim of the present study was to evaluate the bactericidal effects of fabrics coated with the hydroxyapatite-binding silver/titanium dioxide ceramic nanocomposite “Earth-plus”. Methods Bactericidal activities of woven and nonwoven fabrics coated with Earth-plus were investigated by the time-kill curve method using nine bacterial strains, including three Staphylococcus aureus , three Escherichia coli , and three Pseudomonas aeruginosa strains. Results The numbers of viable S. aureus and E. coli cells on both fabrics coated with Earth-plus decreased to below 2 log 10 colony-forming units/mL in six hours and reached the detection limit in 18 hours. Viable cell counts of P. aeruginosa on both fabrics coated with Earth-plus could not be detected after 3–6 hours. Viable cells on woven fabrics showed a more rapid decline than those on nonwoven fabrics. Bacterial cell counts of the nine strains on fabrics without Earth-plus failed to decrease even after 18 hours. Conclusion Woven cotton and nonwoven polypropylene fabrics were shown to have excellent antibacterial potential. The woven fabric was more bactericidal than the nonwoven fabric.

show abstract

Ultrastructural Study of Chitosan Effects on Klebsiella and Staphylococci

Cited by 42 publications

References 6 publications

Insights into the Mode of Action of Chitosan as an Antibacterial Compound

Insights into the Mode of Action of Chitosan as an Antibacterial Compound

Evaluation of Chitosan Gel as Antibiotic and Photosensitizer Delivery

Bactericidal activities of woven cotton and nonwoven polypropylene fabrics coated with hydroxyapatite-binding silver/titanium dioxide ceramic nanocomposite "Earth-plus"

Contact Info

Product

Resources

About

Ultrastructural Study of Chitosan Effects on Klebsiella and Staphylococci

Cited by 42 publications

References 6 publications

Insights into the Mode of Action of Chitosan as an Antibacterial Compound

Insights into the Mode of Action of Chitosan as an Antibacterial Compound

Evaluation of Chitosan Gel as Antibiotic and Photosensitizer Delivery

Bactericidal activities of woven cotton and nonwoven polypropylene fabrics coated with hydroxyapatite-binding silver/titanium dioxide ceramic nanocomposite &quot;Earth-plus&quot;

Contact Info

Product

Resources

About

Bactericidal activities of woven cotton and nonwoven polypropylene fabrics coated with hydroxyapatite-binding silver/titanium dioxide ceramic nanocomposite "Earth-plus"