Antimicrobial activity of Citrox bioflavonoid preparations against oral microorganisms

Cyclodextrins as Multi-Functional Ingredients in Dentistry

Cyclodextrins are present in a variety of oral hygiene compositions. The present work describes the role of cyclodextrins in several toothpastes and mouthwashes that are already available in the market, as well as their prospective use in other applications as investigated in studies in the literature. Moreover, cyclodextrins are under study for the development of materials used in various techniques of dental repair, such as fillings, cements and binders therein. Their role in each of the innovative materials is presented. Finally, the prospect of the use of cyclodextrin-based delivery systems for the oral cavity is introduced, with a focus on new cyclodextrin molecules with dual action as bone-targeting agents and osteogenic drugs, and on new cross-linked cyclodextrin particles with a high drug loading and sustained drug delivery profile for the treatment of diseases that require prolonged action, such as periodontitis. In conclusion, cyclodextrins are herein demonstrated to act as versatile and multi-action ingredients with a broad range of applications in dentistry.

Effectiveness of mouthwashes on reducing SARS-CoV-2 viral load in oral cavity: a systematic review and meta-analysis

BACKGROUND

The risk of SARS-COV-2 transmission is relatively high during dental procedures. A study was conducted to investigate the effects of mouthwashes on SARS-COV-2 viral load reduction in the oral cavity.

METHODS

A systematic search was performed in PubMed, EMBASE, Scopus, Web of Science, and Cochrane library for relevant studies up to 20 July, 2022. Randomized and non-randomized clinical trial and quasi-experimental studies evaluating patients with Covid-19 infection (patients) who used mouthwashes (intervention) compared to the same patients before using the mouthwash (comparison) for reducing the SARS-COV-2 load or increasing the cycle threshold (Ct) value (outcome) were searched according to PICO components. Three independent reviewers conducted literature screening and data extraction. The Modified Downs and Black checklist was used for quality assessment. A meta-analysis was performed with a random effects model in the Revman 5.4.1software using the mean difference (MD) of cycle threshold (Ct) values.

RESULTS

Of 1653 articles, 9 with a high methodological quality were included. A meta-analysis indicated that 1% Povidone-iodine (PVP-I) was an effective mouthwash for reducing the SARS-COV-2 viral load [MD 3.61 (95% confidence interval 1.03, 6.19)]. Cetylpyridinium chloride (CPC) [MD 0.61 (95% confidence interval -1.03, 2.25)] and Chlorhexidine gluconate (CHX) [MD -0.04 95% confidence interval (-1.20, 1.12)] were not effective against SARS-COV-2.

CONCLUSION

Using mouthwashes containing PVP-I may be recommended for reducing the SARS-COV-2 viral load in the oral cavity of patients before and during dental procedures, while the evidence is not sufficient for such effects for CPC and CHX-containing mouthwashes.

The Effect Citrox BCL on Legionella pneumophila Mechanisms of Biofilm Formation, Oxidative Stress and Virulence

Legionella pneumophila is responsible for causing Legionnaires’ disease and Pontiac fever, also known as legionellosis. The aim of this study was to investigate the mechanistic effect of a mixture of natural antimicrobials (Citrox BCL) in preventing L. pneumophila biofilm formation and reducing its in vitro virulence. The minimum inhibitory concentrations were detected at 0.06%, and the MBC was established at 0.125%. Based on the growth curve profile, the sub-inhibitory concentration of 0.02% was further used to study the mechanistic implications in the absence of a cytotoxic effect on A549 cells. At 24 h post-infection, Citrox BCL reduced (p = 0.005) the intracellular growth of L. pneumophila when the A549 cells or the bacteria were pre-treated with 0.02% Citrox BCL. This result was replicated when Citrox BCL was added during the 24 h infection assay leading to a reduction in intracellular growth (p = 0.003). Herein we show that at the sub-inhibitory concentration of 0.02%, Citrox CBL lowers the ROS levels in infected A549 cells and causes a 45% reduction in L. pneumophila EPS production, a reduction associated with the decline in biofilm formation. Overall, our results corroborate the low c-di-GMP production with the decrease in biofilm formation and low EPS levels. The low EPS levels seemed to be caused by the downregulation of the tatB and tatC gene expressions. Moreover, inhibition of pvcA and pvcB gene expressions, leading to lower siderophore levels, suggests that Citrox BCL reduces the ability of L. pneumophila to sequester iron and reduce biofilm formation through iron starvation.

Oral Antiseptics against SARS-CoV-2: A Literature Review

Dentists are health care workers with the highest risk of exposure to COVID-19, because the oral cavity is considered to be a reservoir for SARS-CoV-2 transmission. The identification of SARS-CoV-2 in saliva, the generation of aerosols, and the proximity to patients during dental procedures are conditions that have led to these health care workers implementing additional disinfection strategies for their protection. Oral antiseptics are widely used chemical substances due to their ability to reduce the number of microorganisms. Although there is still no evidence that they can prevent the transmission of SARS-CoV-2, some preoperative oral antiseptics have been recommended as control measures, by different health institutions worldwide, to reduce the number of microorganisms in aerosols and droplets during dental procedures. Therefore, this review presents the current recommendations for the use of oral antiseptics against SARS-CoV-2 and analyzes the different oral antiseptic options used in dentistry.

Antibacterial and Antibiofilm Potency of XF Drugs, Impact of Photodynamic Activation and Synergy With Antibiotics

With increasing incidence of antimicrobial resistance, there is an urgent need for novel and effective antibacterials. Destiny Pharma plc have developed a series of porphyrin-based XF drugs, some with dual mechanisms of antibacterial action. An innate mechanism acts through binding to the outer bacterial membrane and a separate, light-activated, photodynamic (PD) mechanism, acts via the generation of reactive oxygen species. This study aimed to assess the innate and PD associated antibacterial activity of XF drugs against planktonic bacteria, their biofilms and combinational effects with conventional antibiotics. Minimum inhibitory concentrations (MICs) were determined for 3 XF drugs against 114 bacterial isolates. MICs for XF-73 and XF-70 were determined (± PD). DPD-207 was designed to not exhibit PD action due to its structure. XF-drugs (± PD) were further assessed for synergy with conventional antibiotics (using a checkerboard assay) and antibiofilm activity against susceptible strains. XF drugs were innately active against all tested Gram-positive isolates. PD action significantly increased bacterial susceptibility to XF-73 and XF-70 for all Gram-positive isolates. Generally, the XF drugs exhibited higher MICs against Gram-negative isolates, however PD significantly enhanced potency, particularly for XF-70. XF-73 and XF-70 exhibited synergy with ertapenem against a methicillin resistant Staphylococcus aureus (MRSA) strain (± PD) and XF-73 with polymyxin B (± PD) against Pseudomonas aeruginosa. No antagonism was seen between the XF drugs and any of the 5 antibiotics tested. The antibiofilm effect of XF drugs was also observed for all Staphylococcus isolates tested. Generally, PD did not enhance activity for other bacterial isolates tested with the exception of XF-73 against Acinetobacter baumannii biofilms. XF drugs exhibited significant antimicrobial activity against Gram-positive bacteria, with PD enhancement of bacterial susceptibility. Additionally, XF drugs displayed synergy with conventional antibiotics and demonstrated antibiofilm effects.

Effects of bioflavonoid-containing mouth rinses on optical properties of tooth-coloured dental restorative materials

This study investigated differences in colour (ΔE₀₀) and translucency parameter (ΔTP₀₀) of nanofilled/microhybrid composites and a glass-ionomer cement following immersion in bioflavonoid (Citrox)- or chlorhexidine-based mouth rinses. Sixty disc-shaped specimens (N = 5/group) of Filtek Supreme (3M), Gradia Anterior (GC) and Fuji IX (GC) were exposed to Citrox/0.2%CHX (Perio+0.2, Curaprox), Citrox/0.09%CHX (Perio+0.09, Curaprox), 0.2%CHX (Savacol, Colgate-Palmolive) or distilled water by 2-min agitation daily for 28 days in an orbital shaker at 200 rpm at 37 °C. Colour recordings were performed using a clinical spectrophometer to obtain CIELab coordinates. General linear model, ANOVA, Tukey test (α = 0.05) and Pearson correlation test were used to analyse data. ΔE₀₀ ranged between 0.33 (Gradia_Savacol_T28) and 6.35 (Fuji_Savacol_T28) (p < 0.001). ΔTP₀₀ ranged between 0.36 (Fuji_ Perio+0.2) and 1.73 (Fuji_Savacol) (p < 0.05). Savacol resulted in higher ΔE₀₀ of Filtek and Fuji and ΔTP₀₀ of Filtek than Perio+0.09 and Perio+0.2 (p = 0.005). Perio+0.09 and Perio+0.2 resulted in higher ΔE₀₀ at T7 than T28 (p < 0.05). There was no correlation between ΔTP₀₀ and ΔE₀₀ (r = 0.445, p = 0.147). Generally, Perio+0.2 and Perio+0.09 mouth rinses produced similar or lower ΔE₀₀ and ΔTP₀₀ than Savacol. GIC Fuji showed higher ΔE₀₀ and similar or higher ΔTP₀₀ than composites Filtek and Gradia. ΔE₀₀ in all materials decreased in Perio+0.2 and Perio+0.09 over time.

Efficacy of Pre-Procedural Mouthwashes against SARS-CoV-2: A Systematic Review of Randomized Controlled Trials

The oral mucosa is one of the first sites to be affected by the SARS-CoV-2. For this reason, healthcare providers performing aerosol-generating procedures (AGPs) in the oral cavity are at high risk of infection with COVID-19. The aim of this systematic review is to verify whether there is evidence in the literature describing a decrease in the salivary viral load of SARS-CoV-2 after using different mouthwashes. An electronic search of the MEDLINE database (via PubMed), Web of Science, SCOPUS, and the Cochrane library database was carried out. The criteria used were those described by the PRISMA® Statement. Randomized controlled trial studies that have used mouthwashes as a form of intervention to reduce the viral load in saliva were included. The risk of bias was analyzed using the Joanna Briggs Institute Critical Appraisal Tool. Ultimately, eight articles were included that met the established criteria. Based on the evidence currently available in the literature, PVP-I, CHX and CPC present significant virucidal activity against SARS-CoV-2 in saliva and could be used as pre-procedural mouthwashes to reduce the risk of cross-infection.

Inhibition of Several Bacterial Species Isolated from Squid and Shrimp Skewers by Different Natural Edible Compounds

Seafood is an excellent source of nutrients, essential for a healthy diet, ranging from proteins and fatty acids to vitamins and minerals. Seafood products are highly perishable foods due to their nutritional characteristics and composition. The application of nontoxic, natural, and edible preservatives to extend the shelf-life and inhibit bacterial proliferation of several foods has been a hot topic. Consequently, this work aimed to perform the microbiological characterization of squid and shrimp skewers during their shelf-life (five days) and evaluate the susceptibility of randomly isolated microorganisms to several natural edible compounds so that their application for the preservation and shelf-life extension of the product might be analyzed in the future. The product had considerably high total microorganisms loads of about 5 log CFU/g at day zero and 9 log CFU/g at day five. In addition, high bacterial counts of Pseudomonas spp., Enterobacterales, and lactic acid bacteria (LAB) were found, especially on the last day of storage, being Pseudomonas the dominant genus. However, no Escherichia coli or Listeria monocytogenes were detected on the analyzed samples. One hundred bacterial isolates were randomly selected and identified through 16s rRNA sequencing, resulting in the detection of several Enterobacterales, Pseudomonas spp., and LAB. The antibacterial activity of carvacrol, olive leaf extract, limonene, Citrox®, different chitosans, and ethanolic propolis extracts was evaluated by the agar diffusion method, and the minimum inhibitory concentration was determined only for Citrox® since only this solution could inhibit all the identified isolates. At concentrations higher than or equal to 1.69% (v/v), Citrox® demonstrated bacteriostatic and bactericidal activity to 97% and 3% of the isolates, respectively. To our knowledge, there are no available data about the effectiveness of this commercial product on seafood isolates. Although preliminary, this study showed evidence that Citrox® has the potential to be used as a natural preservative in these seafood products, improving food safety and quality while reducing waste. However, further studies are required, such as developing a Citrox®-based coating and its application on this matrix to validate its antimicrobial effect.

[Assessment of antimicrobial activity of bioflavonoid CITROX and chlorhexidine combination against P. gingivalis (in vitro)]

OBJECTIVE

The aim of the study - evaluation of the antiseptic properties of the combination of chlorhexidine and bioflavonoid CITROX against P. gingivalis.

MATERIAL AND METHODS

Clinical isolates of microbial cultures from the collection of the Department of Microbiology, Immunology, Virology of the Moscow State Medical University named after A.I. Evdokimov: P. gingivalis. Primary seeding of the studied material was carried out on nutrient media produced by Himedia Laboratories Pvt. Limited (India): Colombian agar with the addition of 5% defibrinated blood and a selective additive for the isolation of non-spore anaerobes. To conduct the experiment, a thermostatic rotary system - RTS-1 (Biosan, Latvia) was used, which performs a modern type of mixing due to the formation of a vortex-type diffusing effect. The interpretation of the results was carried out by changing the optical density index (the indicator in McFarland units) at a wavelength of λ = 850 nm.

RESULTS

The combination of CITROX + chlorhexidine 0.05% more effectively suppresses the growth of periodotopathogenic bacteria than chlorhexidine 0.05%, prolonging the adaptive phase (lag phase) of the growth of P.gingivalis bacteria and can be considered as an alternative to chlorhexidine without additives. Prolongation of the lag phase increases the time until the first clinical symptoms appear, as a result, the body has more time to form an immune response.

CONCLUSION

The combination of the complex of bioflavonoids CITROX and chlorhexidine bigluconate in concentrations of 0.05% and 0.2% is active against P. gingivalis and can be considered as an alternative to chlorhexidine without additives. The inclusion of CITROX in the rinse aid reduces the concentration of chlorhexidine in the rinse aid, which can lead to a decrease in the severity of undesirable effects and be considered as an alternative remedy in the treatment of periodontal diseases.

Controversy around parabens: Alternative strategies for preservative use in cosmetics and personal care products

Parabens usage as preservatives in cosmetics and personal care products have been debated among scientists and consumers. Parabens are easy to production, effective and cheap, but its safety status remains controversial. Other popular cosmetics preservatives are formaldehyde, triclosan, methylisothiazolinone, methylchloroisothiazolinone, phenoxyethanol, benzyl alcohol and sodium benzoate. Although their high antimicrobial effectiveness, they also exhibit some adverse health effects. Lately, scientists have shown that natural substances such as essential oils and plant extracts present antimicrobial potential. However, their use in cosmetic is a challenge. The present review article is a comprehensive summary of the available methods to prevent microbial contamination of cosmetics and personal care products, which can allow reducing the use of parabens in these products.

Antiviral Activity of Reagents in Mouth Rinses against SARS-CoV-2

The oral cavity, an essential part of the upper aerodigestive tract, is believed to play an important role in the pathogenicity and transmission of SARS-CoV-2. The identification of targeted antiviral mouth rinses to reduce salivary viral load would contribute to reducing the COVID-19 pandemic. While awaiting the results of significant clinical studies, which to date do not exist, the commercial availability of mouth rinses leads us to search among them for reagents that would have specific antiviral properties with respect to SARS-CoV-2. The challenges facing this target were examined for 7 reagents found in commercially available mouth rinses and listed on the ClinicalTrials.gov website: povidone-iodine, chlorhexidine, hydrogen peroxide, cyclodextrin, Citrox, cetylpyridinium chloride, and essential oils. Because SARS-CoV-2 is an enveloped virus, many reagents target the outer lipid membrane. Moreover, some of them can act on the capsid by denaturing proteins. Until now, there has been no scientific evidence to recommend mouth rinses with an anti-SARS-CoV-2 effect to control the viral load in the oral cavity. This critical review indicates that current knowledge of these reagents would likely improve trends in salivary viral load status. This finding is a strong sign to encourage clinical research for which quality protocols are already available in the literature.

Toothpastes with Enzymes Support Gum Health and Reduce Plaque Formation

Enzymes in toothpastes can support host immune responses, and thus maintain oral health. This study aimed to investigate gingival health and the plaque-reducing effects of enzyme-containing toothpastes. A laboratory study tested the antimicrobial potential of different enzyme-containing toothpaste formulations. Two promising formulations (enzyme-containing toothpastes with glucose oxidase and D-glucose with (C+) and without Citrox (C-) Citrox) were investigated in a clinical crossover trial (two slurries: sodium lauryl sulfate-containing (SLS), a toothpaste without SLS (reference), and water). Subjects (n = 20) abstained from toothbrushing for four days and rinsed with a toothpaste slurry. Bleeding on probing (BOP) and plaque indices (PI) were measured. A mixed linear model was used to statistically compare the slurries with respect to BOP and PI change. The in vitro bacterial growth-inhibiting evaluation showed the best results for SLS, followed by C+ and C-. The change in BOP and PI exhibited statistically significant differences to water rinsing (BOP; PI changes in % points (difference of the baseline and post-rinse values: water = 8.8%; 90.0%; C+ = -1.4%; 80.4%; SLS = 1.5%; 72.1%; reference = 0.8%; 77.5%; C- = -1.8%; 75.1%). All slurries exhibited anti-gingivitis and anti-plaque effects, resulting in a prophylactic benefit for limited-access regions during brushing.

Anti-biofilm efficacy of a medieval treatment for bacterial infection requires the combination of multiple ingredients

Novel antimicrobials are urgently needed to combat drug-resistant bacteria and to overcome the inherent difficulties in treating biofilm-associated infections. Studying plants and other natural materials used in historical infection remedies may enable further discoveries to help fill the antibiotic discovery gap. We previously reconstructed a 1,000-year-old remedy containing onion, garlic, wine, and bile salts, known as 'Bald's eyesalve', and showed it had promising antibacterial activity. In this current paper, we have found this bactericidal activity extends to a range of Gram-negative and Gram-positive wound pathogens in planktonic culture and, crucially, that this activity is maintained against Acinetobacter baumannii, Stenotrophomonas maltophilia, Staphylococcus aureus, Staphylococcus epidermidis and Streptococcus pyogenes in a soft-tissue wound biofilm model. While the presence of garlic in the mixture can explain the activity against planktonic cultures, garlic has no activity against biofilms. We have found the potent anti-biofilm activity of Bald's eyesalve cannot be attributed to a single ingredient and requires the combination of all ingredients to achieve full activity. Our work highlights the need to explore not only single compounds but also mixtures of natural products for treating biofilm infections and underlines the importance of working with biofilm models when exploring natural products for the anti-biofilm pipeline.

Superior Antibacterial Activity of Integral Lemon Pectin Extracted via Hydrodynamic Cavitation

Pectin extracted via hydrodynamic cavitation in water only from waste lemon peel and further isolated via freeze drying displays significant antibacterial activity against Staphylococcus aureus, a Gram positive pathogen which easily contaminates food. The antibacterial effect of the new IntegroPectin is largely superior to that of commercial citrus pectin, opening the way to advanced applications of a new bioproduct now obtainable in large amounts and at low cost from citrus juice industry's waste.

COVID-19: A Recommendation to Examine the Effect of Mouthrinses with β-Cyclodextrin Combined with Citrox in Preventing Infection and Progression

Considered to be a major portal of entry for infectious agents, the oral cavity is directly associated with the evolutionary process of SARS-CoV-2 in its inhalation of ambient particles in the air and in expectorations. Some new generations of mouth rinses currently on the market have ingredients that could contribute to lower the SARS-CoV-2 viral load, and thus facilitate the fight against oral transmission. If chlorhexidine, a usual component of mouth rinse, is not efficient to kill SARS-CoV-2, the use of a mouth rinses and/or with local nasal applications that contain β-cyclodextrins combined with flavonoids agents, such as Citrox, could provide valuable adjunctive treatment to reduce the viral load of saliva and nasopharyngeal microbiota, including potential SARS-CoV-2 carriage. We urge national agencies and authorities to start clinical trials to evaluate the preventive effects of βCD-Citrox therapeutic oral biofilm rinses in reducing the viral load of the infection and possibly disease progression.

Antimicrobial Effect of Thymus capitatus and Citrus limon var. pompia as Raw Extracts and Nanovesicles

In view of the increasing interest in natural antimicrobial molecules, this study screened the ability of Thymus capitatus (TC) essential oil and Citrus limon var. pompia (CLP) extract as raw extracts or incorporated in vesicular nanocarriers against Streptococcus mutans and Candida albicans. After fingerprint, TC or CLP were mixed with lecithin and water to produce liposomes, or different ratios of water/glycerol or water/propylene glycol (PG) to produce glycerosomes and penetration enhancer vesicles (PEVs), respectively. Neither the raw extracts nor the nanovesicles showed cytotoxicity against human gingival fibroblasts at all the concentrations tested (1, 10, 100 μg/mL). The disc diffusion method, MIC-MBC/MFC, time-kill assay, and transmission electron microscopy (TEM) demonstrated the highest antimicrobial potential of TC against S. mutans and C. albicans. The very high presence of the phenol, carvacrol, in TC (90.1%) could explain the lethal effect against the yeast, killing up to 70% of Candida and not just arresting its growth. CLP, rich in polyphenols, acted in a similar way to TC in reducing S. mutans, while the data showed a fungistatic rather than a fungicidal activity. The phospholipid vesicles behaved similarly, suggesting that the transported extract was not the only factor to be considered in the outcomes, but also their components had an important role. Even if other investigations are necessary, TC and CLP incorporated in nanocarriers could be a promising and safe antimicrobial in caries prevention.

Evaluation of Antibacterial Effect of Propolis and its Application in Mouthwash Production

Objectives:

Our purpose was to determine the antibacterial properties of propolis and to evaluate its use as an antibacterial mouthwash with minimal complications.

Materials and Methods:

In this experimental laboratory study, an alcoholic propolis extract was prepared. The minimum inhibitory concentration (MIC) was calculated for four bacterial species including Staphylococcus aureus (S. aureus), Streptococcus mutans (S. mutans), Lactobacillus acidophilus (L. acidophilus), and Enterococcus faecalis (E. faecalis) using agar dilution. According to the MIC, a propolis antibacterial mouthwash was produced and compared to water, chlorhexidine (CHX), and Listerine using laboratory rats for clinical examination. Salivary specimens of rats were collected at 12 hours, 1 week, and 2 weeks after using the mouthwash and examined by real-time polymerase chain reaction (RT-PCR). Data were analyzed using one-way analysis of variance (ANOVA) and repeated measures ANOVA (α=0.05).

Results:

The results of agar dilution by the number of colony-forming units showed the lowest MIC for S. aureus and the highest for L. acidophilus. Our RT-PCR findings indicated that water alone had no effect on the level of oral bacteria. Propolis mouthwash showed a significant difference with CHX and Listerine (P<0.05) in terms of the number of S. mutans, E. faecalis, and L. acidophilus colonies, while CHX and Listerine were less efficient. There was no significant difference between CHX and propolis (P=0.110) regarding S. aureus colonies, but Listerine had a lower efficacy than either (P<0.05).

Conclusion:

According to the results, propolis mouthwash was more efficient against the studied oral bacteria compared to CHX and Listerine.

Eradication of Staphylococcus aureus Catheter-Related Biofilm Infections Using ML:8 and Citrox

Staphylococci are a leading cause of catheter-related infections (CRIs) due to biofilm formation. CRIs are typically managed by either device removal or systemic antibiotics, often in combination with catheter lock solutions (CLSs). CLSs provide high concentrations of the antimicrobial agent at the site of infection. However, the most effective CLSs against staphylococcal biofilm-associated infections have yet to be determined. The purpose of this study was to evaluate the efficacy and suitability of two newly described antimicrobial agents, ML:8 and Citrox, as CLSs against Staphylococcus aureus biofilms. ML:8 (1% [vol/vol]) and Citrox (1% [vol/vol]), containing caprylic acid and flavonoids, respectively, were used to treat S. aureus biofilms grown in vitro using newly described static and flow biofilm assays. Both agents reduced biofilm viability >97% after 24 h of treatment. Using a rat model of CRI, ML:8 was shown to inactivate early-stage S. aureus biofilms in vivo, while Citrox inactivated established, mature in vivo biofilms. Cytotoxicity and hemolytic activity of ML:8 and Citrox were equivalent to those of other commercially available CLSs. Neither ML:8 nor Citrox induced a cytokine response in human whole blood, and exposure of S. aureus to either agent for 90 days was not associated with any increase in resistance. Taken together, these data reveal the therapeutic potential of these agents for the treatment of S. aureus catheter-related biofilm infections.

Irritant contact dermatitis risk of common topical traditional chinese medicines used for skin-lightening: a pilot clinical trial with 30 volunteers

Topical traditional Chinese medicine- (TTCM-) related contact dermatitis is not uncommon but ignored. Patch and photopatch tests using 6 individual herbal ingredients and Bai-Zhi-Kao (BZK; 白芷膏), a skin-lightening TTCM preparation, were conducted on 30 participants. Twenty-five subjects showed at least 1 positive reaction, including 6 (20.0%) participants who reacted to BZK. The majority reacted to Radix Ampelopsis japonica (Bai-Lian; 白蘞) (60.0%), whereas few reacted to Rhizoma Bletilla striata (Bai-Ji; 白芨) (16.7%), Rhizoma Atractylodis macrocephalae (Bai-Zhu; 白朮) (10.0%), Radix Angelicae dahuricae (Bai-Zhi; 白芷) (3.3%), and Herba asari (Xi-Xin; 細辛) (3.3%). In the photopatch test, 3 participants (10.0%) reacted positively to BZK and 10 to ≥1 constituent; however, all reacted to Radix Angelicae dahuricae (26.7%), Radix Ampelopsis japonica (13.3%), and Rhizoma Bletilla striata (3.3%). In contrast, no subjects showed positive reactions to Sclerotium Poria cocos (Bai-Fu-Ling; 白茯苓). Thus, BZK and its constituents might present potential latent risk of contact dermatitis owing to the possible presence of Radix Ampelopsis japonica and Radix Angelicae dahuricae. Furthermore, TTCMs, particularly cosmetic products, must be used carefully, with ample warning of potential contact dermatitis risk.

Efficacy of commercial natural antimicrobials alone and in combinations against pathogenic and spoilage microorganisms

Microbial control strategies are needed in the food industry to prevent foodborne illnesses and outbreaks and prolong product shelf life. The aim of this study was to investigate and compare the efficacy of the commercial natural antimicrobials white mustard essential oil (WMEO), citrus flavonoid and acid blend (CFAB), olive extract (OE), Nisaplin (a compound containing nisin), and lauric arginate (LAE) alone and in combinations against foodborne pathogens and spoilage microorganisms. MICs of individual and combined antimicrobials against Escherichia coli, Salmonella Enteritidis, Enterobacter aerogenes, Bacillus cereus, Listeria monocytogenes, and Staphylococcus aureus were determined at pH 6.0 and 25 °C. WMEO was most effective against B. cereus and S. aureus, with MICs of 250 and 500 mg/liter, respectively. CFAB inhibited all tested microorganisms, requiring only 12 to 35 mg/liter for gram-positive bacteria. For OE, 2,000 mg/liter was needed to achieve microbial inhibition. Nisaplin at 400 to 1,200 mg/liter inhibited only gram-positive bacteria. LAE was effective at low concentrations and required only 20 to 50 mg/liter to inhibit all tested microorganisms. When WMEO was combined with other antimicrobials, the effects were usually additive except for WMEO plus Nisaplin and WMEO+OE, which had synergistic activity against L. monocytogenes and Salmonella Enteritidis, respectively. An antagonistic effect was observed for WMEO+CFAB against E. aerogenes. For WMEO+LAE+CFAB, additive antimicrobial effects were noted against all strains tested except S. aureus, where a synergistic effect occurred. These findings suggest that these commercial natural antimicrobials have potential to enhance food safety by inhibiting foodborne pathogens and extending product shelf life.

Biocide activity against urinary catheter pathogens

Antimicrobial effects of essential oils against bacteria associated with urinary catheter infection was assessed. Tests were performed on 14 different bacterial species cultured either planktonically or as biofilms. Biofilms were found to be up to 8-fold more tolerant of the test agents. Higher antimicrobial tolerance was also evident in tests conducted in artificial urine. Eugenol exhibited higher antimicrobial effects against both planktonic cells and biofilms than did terpinen, tea tree oil, and cineole.