Methods: The in vitro effect of tannins was studied against MRSA reference strain (ATCC 43300) and MRSA clinical strains utilizing antimicrobial assays in conjunction with both scanning and transmission electron microscopy. To reveal the influence of tannins in MRSA protein synthesis disruption, we utilized next-generation sequencing (NGS) to provide further insight into the novel protein synthesis transcriptional response of MRSA exposed to these compounds.
Results: Tannins possessed both bacteriostatic and bactericidal activity with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of 0.78 and 1.56 mg/mL, respectively, against all tested MRSA. Scanning and transmission electron microscopy of MRSA treated with tannins showed decrease in cellular volume, indicating disruption of protein synthesis.
Conclusion: Analysis of a genome-wide transcriptional profile of the reference strain ATCC 43300 MRSA in response to tannins has led to the finding that tannins induced significant modulation in essential ribosome pathways, which caused a reduction in the translation processes that lead to inhibition of protein synthesis and obviation of bacterial growth. These findings highlight the potential of tannins as new promising anti-MRSA agents in clinical application such as body wash and topical cream or ointments.
METHODS: Time-kill analysis of one MRSA reference strain (ATCC 43300) and three clinical isolates (WM3, BM1 and KJ7) for both compounds was first performed to provide the bacteriostatic/bactericidal profile. Then, MRSA ATCC 43300 strain treated with both compounds was interrogated by NGS.
RESULTS: Both stigmasterol and lupeol possessed bacteriostatic properties against all MRSA tested; however, lupeol exhibited both bacteriostatic and bactericidal properties within the same minimum inhibitory concentration and minimum bactericidal concentration values against BM1 (12.5mg/mL). Transcriptome profiling of MRSA ATCC 43300 revealed significant modulation of gene expression with multiple desirable targets by both compounds, which caused a reduction in the translation processes leading to inhibition of protein synthesis and prevention of bacterial growth.
CONCLUSIONS: This study highlights the potential of both stigmasterol and lupeol as new promising anti-MRSA agents.
METHODS: First, the essential oils were obtained using a Clevenger-type apparatus. Then, the essential oils compositions were identified by chromatography methods including GC-FID and GC-MS. For the next step, DPPH radical scavenging activity (RSA), β-carotene bleaching (BCB), and ferrous ion chelating ability (FIC) were chosen to evaluate the essential oils antioxidant activity. Finally, disc diffusion assay and minimum inhibitory concentration method (MIC) was applied to investigate antimicrobial activity of the rhizomes and leaves oils of E. sayapensis against 18 microorganisms.
RESULTS: All of the oils contained oxygenated monoterpenes (leaves: 74.18%, stems: 75.60%, and rhizome: 54.61%), The essential oil obtained from leaves contained high amount of carvone (21.38%), cis-carveol (13.49%); The rhizomes oil was rich in linalool formate (25.47%), eugenol (11.84%); and the stems oil was dominated by α-terpineol (39.86%), linalool formate (30.55%). The leaves oil represented the highest ability in all of the antioxidant activity tests. For antimicrobial activity, the rhizome oil presented more active when compared to leaves oil against Bacillus subtilis, Bacillus thuringiensis, Staphylococcus aureus, methicillin resistant Staphylococcus aureus (MRSA), Aeromonas hydrophila, Escherichia coli, Enterobacter aerogenes, Proteus mirabilis, Shigella sonnei, Serratia marcescens, Vibrio parahaemolyticus, Candida albicans, and Candida parapsilosis.
CONCLUSIONS: The most components of the essential oils belong to oxygenated monoterpenes. Linalool formate, carvone, and α-terpineol are found as the most abundant compounds in the oils of the different parts of E. sayapensis. The rhizomes oil can prevent the growth of wide spectrum microorganisms; however, the oils are not highly potent in antioxidant assays.
METHODS: A total of 47 CRC cases previously diagnosed by histopathological examination were reviewed for the presence of PDCs and graded accordingly. The association between PDC grades with clinicopathological and demographic characteristics was statistically analysed.
RESULTS: Out of the 47 cases with PDCs, most of them were of grade 3 (G3) (n = 27, 57.4%), followed by grade 2 (G2) (n = 13, 27.7%) and grade 1 (G1) (n = 7, 14.9%). Higher PDC grades (G2 and G3) were mainly observed in higher tumour stage (T); T3 (n = 26, 83.9%), T4 (n = 12, 92.3%), N1 (n = 20, 86.9%), N2 (n = 15, 100%). In addition, there was a significant association between PDC grades with the nodal stage (N) (P = 0.013) and the tumour, node and metastasis (TNM) stages (P = 0.012).
CONCLUSION: The PDC grades are useful for assessing the disease prognosis in CRC. A statistically significant association between PDC grades with N and TNM stages suggested that PDC grades are potential predictive parameters for invasive and metastatic risks in CRC.