Explorative in vitro evaluation of the inhibitory effect of Vitellaria paradoxa seed oil extract on Staphylococcal conjunctivitis

More exploration on medicinal plants and other natural products in the present era of increase in poverty level and multi-drug resistance has become crucial. The aim of this study is to explore the inhibitory activities of Vitellaria paradoxa seed oil extract on isolated staphylococcal conjunctivitis. Cultured sample of Staphylococcus aureus isolated from a patient’s eye discharge in the Teaching Hospital Laboratory of the Imo State University, Nigeria having been diagnosed with bacterial conjunctivitis at the eye Clinic. After the incubation period, the diameter of zones of inhibition both horizontal and vertical were measured. Concentrations (100, 50 and 25mg/ml) of the ethanolic seed oil extract of V. paradoxa were assayed for the antibacterial activity - Minimum Inhibitory Concentration (MIC) using the agar well diffusion method. Ethanolic seed oil extract of V. paradoxa at concentration of 100mg /ml exhibited the highest zone of inhibition at 37.4mm for 24hrs followed by 50mg /ml and lowest using 25mg/ml (5.0mm) indicating a concentration-dependent inhibitory effect on Staphylococcal conjunctivitis. S. aureus isolated from conjunctivitis swab was susceptible to ethanolic seed oil extract of V. paradoxa at 100mg/ml, 50mg/ml and 25mg/ml concentrations, suggesting ethanolic extract of V. paradoxa oil as possessing antimicrobial property. Further exploration for its use as an ocular anti-bacterial agent is recommended.

Capsaicin potently blocks Salmonella typhimurium invasion of Vero cells

As at 2021, the center for disease control (CDC) reported that Salmonella causes 1.2 million illness in the United States each year, with a mortality rate approaching 500 deaths per annum. Infants, the elderly, and persons with compromised immunity are the population with higher risk of mortality from this infection. At present there is no commercially available, safe and efficacious vaccine for the control and management of Salmonella typhimurium (S. typhimurium). More so, S. typhimurium has been shown to develop resistance against most antibiotics used for treatment of the infection. Capsaicin, a bioactive compound from Capsicum chinense (C. chinenses) is undoubtedly one of the most widely used spice in the world. This heat producing compound is not only been used as food additive but have been demonstrated to possess unique properties that have pharmacological, physiological, and antimicrobial applications. In this work, the antimicrobial property of pure capsaicin or capsaicin extract against S. typhimurium is tested to determine the compounds effectiveness in S. typhimurium inhibition. Capsaicin extract showed potent inhibition of S. typhimurium growth at concentrations as low as 100 ng/ml, whereas pure capsaicin comparatively showed poorer inhibition of the bacteria. Furthermore, both capsaicin extract and pure capsaicin potently blocked S. typhimurium invasion of an animal cell line in vitro. Taken together, this work revealed that capsaicin might work synergistically with dihydrocapsaicin or the other capsaicinoids to inhibit S. typhimurium growth, whereas individually, capsaicin or dihydrocapsaicin could potently block the bacteria entry and invasion of Vero cells.

Rowan Berries: A Potential Source for Green Synthesis of Extremely Monodisperse Gold and Silver Nanoparticles and Their Antimicrobial Property

Rowanberries (Sorbus aucuparia) are omnipresent in Europe. The medicinal importance of rowanberries is widely known and corresponds to the active ingredients present in the fruits, mainly polyphenols, carotenoids, and organic acids. In the current study, we explored rowanberries for the reduction of gold and silver salts into nanoparticles. Rowanberries-mediated gold nanoparticles (RB-AuNPs) formed within 5 s at room temperature, and silver nanoparticles (RB-AgNPs) formed in 20 min at 90 °C. The produced nanoparticles were thoroughly characterized by UV-Vis spectroscopy, scanning electron microscopy (SEM), energy dispersive X-ray (EDX), transmission electron microscopy (TEM), dynamic light scattering (DLS), single-particle inductively coupled plasma–mass spectrometry (sp-ICP-MS), thermogravimetric analysis (TGA), Fourier transform-infrared spectroscopy (FT-IR) and matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF). The characterization confirmed that the nanoparticles are highly monodisperse, spherical, stable over long periods, and exhibit a high negative zeta potential values. The produced RB-AuNPs and RB-AgNPs were 90–100 nm and 20–30 nm in size with a thick biological corona layer surrounding them, providing extreme stability but lowering the antimicrobial activity. The antimicrobials study of RB-AgNPs revealed that the nanoparticles have antimicrobial potential with an MBC value of 100 µg/mL against P. aeruginosa and 200 µg/mL against E. coli.

Phytochemical Profile, Antimicrobial, Cytotoxic, and Antioxidant Activities of Fresh and Air-Dried Satureja nabateorum Essential Oils

Satureja nabateorum (Danin and Hedge) Bräuchler is a perennial herb in the Lamiaceae family that was discovered and classified in 1998. This green herb is restricted to the mountains overlooking the Dead Sea, specifically in Jordan’s southwest, the Edom mountains, and the Tubas mountains in Palestine. Gas chromatography-mass spectrometry (GC-MS) analysis of essential oil (EO) of air-dried and fresh S. nabateorum resulted in the identification of 30 and 42 phytochemicals accounting for 99.56 and 98.64% of the EO, respectively. Thymol (46.07 ± 1.1 and 40.64 ± 1.21%) was the major compound, followed by its biosynthetic precursors γ-terpinene (21.15 ± 1.05% and 20.65 ± 1.12%), and p-cymene (15.02 ± 1.02% and 11.51 ± 0.97%), respectively. Microdilution assay was used to evaluate the antimicrobial property of EOs against Staphylococcus aureus (ATCC 25923), clinical isolate Methicillin-Resistant Staphylococcus aureus (MRSA), Enterococcus faecium (ATCC 700221) Klebsiella pneumoniae (ATCC 13883), Proteus vulgaris (ATCC 700221), Escherichia coli (ATCC 25922) and Pseudomonas aeruginosa (ATCC 27853) and Candida albicans (ATCC-90028). With a MIC of 0.135 μg/mL, the EOs has the most potent antibacterial action against K. pneumonia. Both EOs display good antifungal efficacy against C. albicans, with a MIC value of 0.75 μg/mL, which was better than that of Fluconazole’s (positive control, MIC = 1.56 μg/mL). The antioxidant capacity of EOs extracted from air-dried and fresh S. nabateorum was determined using the DPPH assay, with IC50 values of 4.78 ± 0.41 and 5.37 ± 0.40 μg/mL, respectively. The tested EOs showed significant cytotoxicity against Hela, HepG2, and COLO-205 cells, with IC50 values ranging from 82 ± 0.98 to 256 ± 1.95 μg/mL. The current work shows there is a possibility to use the S. nabateorum EOs for various applications.

Preparation and Assessment of Antimicrobial Property of Resin Based Composites Impregnated with Proanthocyanidin and Titanium Dioxide

OBJECTIVE: To synthesize three experimental resin based composites (RBCs) out of a commercial preperation (Control) by impregnating into each a fixed weight (0.01%) of titanium dioxide (TiO2) and three different weight % (0.01, 0.02 and 0.03) of proanthocyanidin (PA) and to compare antibacterial property, from the zones of inhibition of streptococcus mutans (S. mutans), of the specimen restorations made in the experimental and control RBCs. METHODOLOGY: In the first phase, Streptococcus mutans were isolated and identified from the oral cavity of patients and identified on the basis of morphogenic appearance of colonies and confirmed through catalase test and microscopic examination. Isolates were then incubated and cultured for sensitivity. Specimens for control and experimental RBCs were made through a metallic mold having 2mm thickness and 5mm diameter for all the 4 groups. Specimen restorations made in the commercial as supplied RBC acted as the control (Group A). Specimen restorations in the Group B, C, and D were made in each of the experimental RBCs modified with 0.01% proanthocyanidin (PA) and 0.01% titanium dioxide (TiO2), 0.02% PA and 0.01% TiO2 and 0.03% PA and 0.01% TiO2. The antimicrobial property of all the specimen restorations in all the groups was evaluated by Bauer-Kirby (Disc Diffusion) method through the formation of zones of inhibition of S. mutans colonies on blood agar plates. Data were computed using SPSS version 21 for descriptive statistics and analyzed using one-way ANOVA with p value 0.05 taken as significant. RESULTS: The range of the zone of inhibition for specimen RBC restorations (N= 12) containing PA and TiO2 was 0.00 for Group A, 10-12mm for Group B, 12-14mm for Group C and 9-10mm for Group D. The mean inhibition zone for the experimental restoration specimens was 11±2mm for Group B, 12.7±1mm for Group C and 9.7±1mm for Group D compared to no inhibition zones (0.00 mm) with the control RBC Group A. The order of the inhibition zones from maximum to minimum was Group C > Group B > Group D > Group A. The differences between the mean values for the control and the experimental RBC restoration specimens were significant (p < 0.000). The specimen restorations in the Group D appeared under cured and could impact on their mechanical properties. CONCLUSION: Irrespective of the mentioned concentrations, impregnating PA and TiO2 rendered the RBC antimicrobial. RBC restorations made with the experimental RBC with 0.02% PA and 0.01% TiO2 proved relatively more effective in terms of antimicrobial effect. KEY WORDS: dental materials, resin based dental restorations, antibacterial resin based composite, proanthocyanidin, titanium dioxide.

Zooshikella harenae sp. nov., Isolated from Pacific Oyster Crassostrea gigas, and Establishment of Zooshikella ganghwensis subsp. marina subsp. nov. and Zooshikella ganghwensis subsp. ganghwensis subsp. nov.

Here, we describe the polyphasic taxonomy of a novel isolated strain WH53T from the genus Zooshikella isolated from the sand sediment located between the lumen of the Crassostrea gigas From Germany. Phylogenetic analysis determined that the strain WH53T had a high similarity to Zooshikella ganghwensis JC2044T (99.57%) and Zooshikella marina LMG 28823T (99.36%). Strain WH53T contained ubiquinone-9 (Q-9) as the predominant menaquinone, and the major fatty acids were C16:0, C16:1ω7c, and C18:1ω7c. Diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, amino phospholipids, and unidentified phospholipids were identified as their polar lipid composition. The DNA G+C content and genome size of strain WH53T were 40.08 mol% and 5,914,969 bp, respectively. Digital DNA–DNA hybridisation (dDDH) for strain WH53T against Z. ganghwensis JC2044T and Z. marina LMG 28823T showed low relatedness values of 26.3% and 26.1%, respectively. The extract of strain WH53T exhibited antimicrobial property. Strain WH53T represents a novel species in the genus Zooshikella. We propose the name of Zooshikella harenae sp. nov., with the type strain WH53T (= DSM 111628T = NCCB 100808T). Furthermore, the dDDH, average nucleotide identity (ANI), percentage of conserved proteins (POCP), and amino acid identity (AAI) value between Z. marina LGM 28823T and Z. ganghwensis DSM 15267T were 79.9%, 97.84%, 76.08%, and 87.01%, respectively, suggesting that both of them should be reclassified as Z. ganghwensis subsp. marina subsp. nov. and Z. ganghwensis subsp. ganghwensis DSM 15267 subsp. nov.

Antimicrobial Properties of Chitosan and Chitosan Derivatives in the Treatment of Enteric Infections

Antibiotics played an important role in controlling the development of enteric infection. However, the emergence of antibiotic resistance and gut dysbiosis led to a growing interest in the use of natural antimicrobial agents as alternatives for therapy and disinfection. Chitosan is a nontoxic natural antimicrobial polymer and is approved by GRAS (Generally Recognized as Safe by the United States Food and Drug Administration). Chitosan and chitosan derivatives can kill microbes by neutralizing negative charges on the microbial surface. Besides, chemical modifications give chitosan derivatives better water solubility and antimicrobial property. This review gives an overview of the preparation of chitosan, its derivatives, and the conjugates with other polymers and nanoparticles with better antimicrobial properties, explains the direct and indirect mechanisms of action of chitosan, and summarizes current treatment for enteric infections as well as the role of chitosan and chitosan derivatives in the antimicrobial agents in enteric infections. Finally, we suggested future directions for further research to improve the treatment of enteric infections and to develop more useful chitosan derivatives and conjugates.