Material compatibility and antimicrobial activity of consumer products commonly used to clean dentures

ABSTRACTRisk assessments of the potential for microbicides to select for reduced bacterial susceptibility have been based largely on data generated through the exposure of bacteria to microbicides in aqueous solution. Since microbicides are normally formulated with multiple excipients, we have investigated the effect of formulation on antimicrobial activity and the induction of bacterial insusceptibility. We tested 8 species of bacteria (7 genera) before and after repeated exposure (14 passages), using a previously validated gradient plating system, for their susceptibilities to the microbicides benzalkonium chloride, benzisothiozolinone, chlorhexidine, didecyldimethyl ammonium chloride, DMDM-hydantoin, polyhexamethylene biguanide, thymol, and triclosan in aqueous solution (nonformulated) and in formulation with excipients often deployed in consumer products. Susceptibilities were also assessed following an additional 14 passages without microbicide to determine the stability of any susceptibility changes. MICs and minimum bactericidal concentrations (MBC) were on average 11-fold lower for formulated microbicides than for nonformulated microbicides. After exposure to the antimicrobial compounds, of 72 combinations of microbicide and bacterium there were 19 ≥4-fold (mean, 8-fold) increases in MIC for nonformulated and 8 ≥4-fold (mean, 2-fold) increases in MIC for formulated microbicides. Furthermore, there were 20 ≥4-fold increases in MBC (mean, 8-fold) for nonformulated and 10 ≥4-fold (mean, 2-fold) increases in MBC for formulated microbicides. Susceptibility decreases fully or partially reverted back to preexposure values for 49% of MICs and 72% of MBCs after further passage. In summary, formulated microbicides exhibited greater antibacterial potency than unformulated actives and susceptibility decreases after repeated exposure were lower in frequency and extent.

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Biosynthesis and Characterization of Zinc Nano particles Using Calocybe Indica and Analysis of their antimicrobial Activity

Journal of University of Shanghai for Science and Technology ◽

10.51201/jusst/21/05341 ◽

2021 ◽

Vol 23 (06) ◽

pp. 887-900

Author(s):

N.K. Sankaranarayanan ◽

◽

Dr.S. Krishnakumari ◽

Keyword(s):

Antimicrobial Activity ◽

Cellular Response ◽

Analytical Techniques ◽

Consumer Products ◽

Nano Particles ◽

Energy Materials ◽

Transmission Electron ◽

Vis Spectroscopy ◽

Calocybe Indica

Recently, the use of nanotechnology has been expanding very rapidly in diverse areas of research, such as consumer products, energy, materials, and medicine. This is especially true in nanomedicine, due to physicochemical properties, such as mechanical, chemical, magnetic, optical, and electrical properties, compared with bulk materials. The first goal of this study was to produce Zinc oxide nanoparticles (ZnONPs) using two different biological resources as reducing agents, Calocybe indica fruiting bodies. The second goal was to investigate the antimicrobial potential of the as-prepared ZnONPs in lung cancer cells. The final goal was to investigate the role of p53 in the cellular response elicited by ZnONPs. The synthesis and characterization of ZnONPs were assessed by various analytical techniques, including ultraviolet-visible (UV-vis) spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and transmission electron microscopy (TEM). The present findings could provide insight into the future development of green synthesis in ZnO nanoparticles, along with their antimicrobial activity.

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Leptospermum scoparium (Mānuka) and Cryptomeria japonica (Sugi) Leaf Essential Oil Seasonal Chemical Variation and Their Effect on Antimicrobial Activity

10.20944/preprints202008.0623.v1 ◽

2020 ◽

Author(s):

Kyung Whan Bang ◽

Gillian Lewis ◽

Silas G. Villas-Boas

Keyword(s):

Antimicrobial Activity ◽

Seasonal Variation ◽

Essential Oil ◽

Essential Oils ◽

Cryptomeria Japonica ◽

Consumer Products ◽

Antimicrobial Efficacy ◽

Future Application ◽

Chemical Variation ◽

Leptospermum Scoparium

This study evaluated the antimicrobial activity of Leptospermum scoparium (Mānuka) and Cryptomeria japonica (Sugi) essential oils and assessed the effect of seasonal chemical variation on the oils’ antimicrobial efficacies. Plate based assays were conducted to elucidate the oils’ spectrum of in vitro antimicrobial activity and to determine the oils’ minimum inhibitory concentrations (MIC) as a measure of antimicrobial efficacy. Gas chromatography – mass spectrometry was adopted to chemically profile oils distilled in different seasons. The resultant compositional information in conjunction with MIC data was used to evaluate the effect of seasonal variation on the oils’ antimicrobial efficacy. Both Mānuka and Sugi essential oils were active against all classes of target microorganisms. However, limited activity was observed against Gram-negative bacteria. The oils displayed consistent chemotypic characteristics regardless of the time of distillation. Nonetheless, there were quantitative differences in compound abundance in both essential oils. Significant differences in the MIC of Sugi essential oil was observed against target microorganisms as a result of seasonal variation in constituent abundances while Mānuka essential oil’s antimicrobial efficacy was unaffected. This study demonstrates that seasonal chemical variation is an important quality assurance parameter to consider for future application of essential oils as antimicrobial agents in consumer products.

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Ultrastructural changes in murine lymphoma cells exposed to ultraviolet-A radiation

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010008482x ◽

1991 ◽

Vol 49 ◽

pp. 104-105

Author(s):

Delma P. Thomas ◽

Dianne E. Godar

Keyword(s):

Medical Devices ◽

Blood Cells ◽

White Blood Cells ◽

Consumer Products ◽

Ultrastructural Changes ◽

Ultraviolet A ◽

Uv Spectrum ◽

Lymphoma Cells ◽

Murine Lymphoma ◽

Transmission Electron

Ultraviolet radiation (UVR) from all three waveband regions of the UV spectrum, UVA (320-400 nm), UVB (290-320 nm), and UVC (200-290 nm), can be emitted by some medical devices and consumer products. Sunlamps can expose the blood to a considerable amount of UVR, particularly UVA and/or UVB. The percent transmission of each waveband through the epidermis to the dermis, which contains blood, increases in the order of increasing wavelength: UVC (10%) < UVB (20%) < UVA (30%). To investigate the effects of UVR on white blood cells, we chose transmission electron microscopy to examine the ultrastructure changes in L5178Y-R murine lymphoma cells.

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