China
Africa
Explore chapters and articles related to this topic
Microbial Biofilms-Aided Resistance and Remedies to Overcome It
Published in Bakrudeen Ali Ahmed Abdul, Microbial Biofilms, 2020
Terpenoids possess an anti-cell adhesion property which makes them potential antibiofilm agents (Lahiri et al. 2019). A phenolic monoterpene, carvacrol is reported to inhibit biofilms of S. aureus and Salmonella enterica (Jose et al. 2017). Dalleau et al. reported the antibiofilm activity of 10 terpenes against Candida species. Of them, carvacrol, geraniol, or thymol inhibits more than 80% biofilms of C. albicans and more than 75% Candida parapsilosis biofilms (Dalleau et al. 2008). Vetiveria zizanioides root extract containing sesquiterpenes a major constituent downregulates adhesin genes like fnbA, fnbB, clfA, thus inhibiting biofilms formed by methicillin-resistant S. aureus (MRSA) (Kannappan et al. 2017). The casbane diterpene, isolated from the ethanolic extract of Croton nepetaefolius, can inhibit in vitro biofilm formed by oral pathogens S. mutans, Streptococcus salivarius, Streptococcus sobrinus, Streptococcus mitis, S. sanguinis, and Streptococcus oralis. The antibacterial effect of this compound is due to the hydrophobic moiety, and a hydrophilic region having two hydrogen bond donor groups which enable the insertion of the compound in the cell membranes, causing the destabilization of the lipid bilayer, which ultimately effects cellular development. However, the biofilm inhibition is presumably related to the growth inhibition only (Sá et al. 2012). Betulinic acid (BA), a triterpene, isolated from the Platanusacerifolia bark is reported to be effective against biofilms of S. aureus (Silva et al. 2019). Khan et al. reported clerodane diterpenoids 16-oxo-cleroda-3, 13(14) E-diene-15 oic acid and kolavenic acid isolated from Polyalthia longifolia var. pendula (Linn.) can significantly inhibit the biofilms of S. mutans, MRSA, K. pneumoniae,and P. mirabilis (Khan et al. 2017)
Fish mucus stabilized iron oxide nanoparticles: fabrication, DNA damage and bactericidal activity
Published in Inorganic and Nano-Metal Chemistry, 2021
G. Chinnadurai, R. Subramanian, P. Selvi
Bactericidal property of iron oxide was examined by agar well diffusion method against pathogenic bacteria such as Escherichia coli (E. coli), Streptococcus faecalis (S. faecali), Streptococcus oralis (S. oralis), Bacteroides fragilis (B. fragilis), and Proteus vulgaris (P. vulgaris).[41,42] Nutrient agar medium (2.8 g) is dissolved in 100 mL of distilled water. The bacterial isolates were suspended in Muller Hinton agar and diluted to 1 × 105 colony forming unit per mL. Wells having 5 mL diameter was cut from the agar using a sterile cork-borer and dispersed in 20 μL in DMSO and poured into the wells. Then the petri plates were subjected to incubate for 24 h at 37 °C. The zone of inhibition was measured and expressed as diameter in millimeters. Streptomycin was used as standard drug for the purpose of comparison. Dimethyl sulfoxide was used to dissolve zero valent iron nanoparticles. The concentrations used were 50, 100, 500, and 1,000 µg/mL.
Amorphous calcium phosphate nanoparticles-based mouthwash: preparation, characterization, and anti-bacterial effects
Published in Green Chemistry Letters and Reviews, 2019
Kimiya Pakravanan, Mahmood Rezaee Roknabadi, Fahimeh Farzanegan, Alireza Hashemzadeh, Majid Darroudi
Representing dental plaque bacteria, three types of microorganisms have been applied and utilized in this project. Streptococcus mutans (ATCC 35668), Streptococcus sanguis (ATCC 10556), and Streptococcus oralis (ATCC 35037) have been obtained from BuAli Research Institute, Mashhad, Iran, which were assigned to be the subculture in 5% sheep's blood agar. Initially, taken from an overnight culture, 5–6 colonies were diluted in a brain heart infusion broth and then incubated in an aerobic environmental condition for the duration of 1–2 h at a temperature of 35°C for the purpose of achieving the concentration of 1.5 × 108CFU/ml. Afterwards, in order to obtain the last concentration of 1.5 × 106CFU/ml, the colonies were carefully diluted with saline solution. The lowest concentration of each antimicrobial agent that hinders the extension of microorganisms that are being examined seem to be recognized as the minimum inhibitory concentration (MIC), which can be diagnosed by observing the absence of turbidity that coordinates with negative control. For antibacterial experiments, 0.5 ml of the diluted microorganisms has been positioned in tubes that contained different concentrations of each nanoparticle; the tubes were then incubated overnight at a temperature of 35–37°C in a closed environment. The determination process of MIC was based on the turbidity that has been measured by the spectrophotometer (Eppendorf AG, Hamburg, Germany). After distinguishing the MIC, 50 ml of the corresponding bacterial suspension was spread in the sheep's blood agar and incubated at 37°C for a period of 24 h. The prepared mouthwash and two known types of mouthwashes, such as Oral-B and chlorhexidine, have been assessed by the agar dilution technique. The mouthwashes have been examined in ten different concentrations including 1/2, 1/4, 1/8, 1/16, 1/32, 1/64, 1/128, 1/256, 1/512, and 1/1024 while taking sterile agar as the diluent. Figures 7 and 8 and Table 1 shown an antibacterial effect scheme, antibacterial image and its values on the growth of three types of microorganisms, respectively.