In-vitro Antibacterial and Antibiofilm Activity of Cinnamomum verum Leaf Oil against Pseudomonas aeruginosa, Staphylococcus aureus and Klebsiella pneumoniae.

Phytomedicines are becoming more popular in treatment of infectious diseases worldwide. Cinnamomum verum essential oil (EO) has been used as a therapeutic alternative for various diseases. This study aimed to evaluate the antibacterial and antibiofilm activity of the C. verum leaf EO against Pseudomonas aeruginosa, Staphylococcus aureus and Klebsiella pneumoniae. Effect of EO vapor on planktonic cells was determined using microatmosphere technique. CLSI M7-A10 method was employed in Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) experiments. Effect of EO on established biofilms was quantified and visualized using XTT and Scanning Electron Microscope (SEM). In-vitro toxicity was evaluated using Human Keratinocytes (HaCaT). Chemical analysis of EO was done using Gas Chromatography- Mass Spectrometry (GC-MS). All tested strains were sensitive to cinnamon oil vapor. EO exhibited 0.5 and 1.0 mg/mL MIC and MBC against all test strains. Minimum Biofilm Inhibitory and Biofilm Eradication Concentrations (MBIC50 and MBEC) were 1.0 and 4.0 mg/mL. SEM indicated cellular shrinkages, cell wall damages, and decreased biofilm densities. Cinnamon oil didn't show any toxicity on HaCaT cell at any concentration tested. Eugenol was the most abundant compound in C. verum oil. C. verum EO shows an antibacterial and antibiofilm activity with minimal toxicity on host.

The Effect of Nutritive and Non-Nutritive Sweeteners on the Growth, Adhesion, and Biofilm Formation of Candida albicans and Candida tropicalis.

OBJECTIVE: To determine the effect of glucose, sucrose, and saccharin on growth, adhesion, and biofilm formation of Candida albicans and Candida tropicalis. MATERIALS AND METHODS: The growth rates of mono-cultures of planktonic C. albicans and C. tropicalis and 1:1 mixed co-cultures were determined in yeast nitrogen broth supplemented with 5% (30 mM) and 10% (60 mM) glucose, sucrose, and saccharin, using optical density measurements at 2-h intervals over a 14-h period. Adhesion and biofilm growth were performed and the growth quantified using a standard 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The biofilm architecture was visualized using scanning electron microscopy. One- and two-way analysis of variance (ANOVA) was performed to analyse the differences among multiple means. RESULTS: The highest planktonic growth was noted in 5% glucose after 14 h (p < 0.05). No significant planktonic growth was observed in either concentration of saccharin. Both the concentrations of glucose and sucrose elicited significantly increased adhesion from MTT activity of 0.017 to >0.019 in mono- as well as co-cultures (p < 0.05), whilst the lower concentration of saccharin significantly dampened the adhesion. Maximal biofilm growth was observed in both species with the lower concentration of sucrose (5%), although a similar concentration of saccharin abrogated biofilm development: the highest MTT value (>0.35) was obtained for glucose and the lowest (>0.15) for saccharin. CONCLUSION: In this study, glucose and sucrose accelerated the growth, adhesion, and biofilm formation of Candida species. However, the non-nutritive sweetener saccharin appeared to dampen, and in some instances suppress, these virulent attributes of Candida.

Culture media profoundly affect Candida albicans and Candida tropicalis growth, adhesion and biofilm development

As there are sparse data on the impact of growth media on the phenomenon of biofilm development for Candida we evaluated the efficacy of three culture media on growth, adhesion and biofilm formation of two pathogenic yeasts, Candida albicans and Candida tropicalis. The planktonic phase yeast growth, either as monocultures or mixed cultures, in sabouraud dextrose broth (SDB), yeast nitrogen base (YNB), and RPMI 1640 was compared, and adhesion as well as biofilm formation were monitored using MTT and crystal violet (CV) assays and scanning electron microscopy. Planktonic cells of C. albicans, C. tropicalis and their 1:1 co-culture showed maximal growth in SDB. C. albicans/C. tropicalis adhesion was significantly facilitated in RPMI 1640 although the YNB elicited the maximum growth for C. tropicalis. Similarly, the biofilm growth was uniformly higher for both species in RPMI 1640, and C. tropicalis was the slower biofilm former in all three media. Scanning electron microscopy images tended to confirm the results of MTT and CV assay. Taken together, our data indicate that researchers should pay heed to the choice of laboratory culture media when comparing relative planktonic/biofilm growth of Candida. There is also a need for standardisation of biofilm development media so as to facilitate cross comparisons between laboratories.

Culture media profoundly affect Candida albicans and Candida tropicalis growth, adhesion and biofilm development.

As there are sparse data on the impact of growth media on the phenomenon of biofilm development for Candida we evaluated the efficacy of three culture media on growth, adhesion and biofilm formation of two pathogenic yeasts, Candida albicans and Candida tropicalis. The planktonic phase yeast growth, either as monocultures or mixed cultures, in sabouraud dextrose broth (SDB), yeast nitrogen base (YNB), and RPMI 1640 was compared, and adhesion as well as biofilm formation were monitored using MTT and crystal violet (CV) assays and scanning electron microscopy. Planktonic cells of C. albicans, C. tropicalis and their 1:1 co-culture showed maximal growth in SDB. C. albicans/C. tropicalis adhesion was significantly facilitated in RPMI 1640 although the YNB elicited the maximum growth for C. tropicalis. Similarly, the biofilm growth was uniformly higher for both species in RPMI 1640, and C. tropicalis was the slower biofilm former in all three media. Scanning electron microscopy images tended to confirm the results of MTT and CV assay. Taken together, our data indicate that researchers should pay heed to the choice of laboratory culture media when comparing relative planktonic/biofilm growth of Candida. There is also a need for standardisation of biofilm development media so as to facilitate cross comparisons between laboratories.