Application of artificial neural networks to classify Avena fatua and Avena sterilis based on seed traits: insights from European Avena populations primarily from the Balkan Region.

BACKGROUND: Avena fatua and A. sterilis are challenging to distinguish due to their strong similarities. However, Artificial Neural Networks (ANN) can effectively extract patterns and identify these species. We measured seed traits of Avena species from 122 locations across the Balkans and from some populations from southern, western, and central Europe (total over 22 000 seeds). The inputs for the ANN model included seed mass, size, color, hairiness, and placement of the awn attachment on the lemma. RESULTS: The ANN model achieved high classification accuracy for A. fatua and A. sterilis (R2 > 0.99, RASE < 0.0003) with no misclassification. Incorporating geographic coordinates as inputs also resulted in successful classification (R2 > 0.99, RASE < 0.000001) with no misclassification. This highlights the significant influence of geographic coordinates on the occurrence of Avena species. The models revealed hidden relationships between morphological traits that are not easily detectable through traditional statistical methods. For example, seed color can be partially predicted by other seed traits combined with geographic coordinates. When comparing the two species, A. fatua predominantly had the lemma attachment point in the upper half, while A. sterilis had it in the lower half. A. sterilis exhibited slightly longer seeds and hairs than A. fatua, while seed hairiness and mass were similar in both species. A. fatua populations primarily had brown, light brown, and black colors, while A. sterilis populations had black, brown, and yellow colors. CONCLUSIONS: Distinguishing A. fatua from A. sterilis based solely on individual characteristics is challenging due to their shared traits and considerable variability of traits within each species. However, it is possible to classify these species by combining multiple seed traits. This approach also has significant potential for exploring relationships among different traits that are typically difficult to assess using conventional methods.

Nutritional Value, Phytochemical Composition and Biological Activities of Lycium barbarum L. fruits from Serbia.

Cultivation of goji berries (GB), fruits of Lycium barbarum L. (Solanaceae), is expanding worldwide, including in Europe. In this study, a comparative analysis of the nutritional value, chemical composition and in vitro biological activities of GB from different locations in Serbia was performed. Proximate compositions were evaluated according to standard methods. Minerals were assessed by inductively coupled plasma techniques, while fatty acids, sterols, and phenolic profiles were analyzed by gas- and liquid chromatography-based techniques coupled with flame-ionization, mass spectrometry, or diode array detection. The total content of phenolics, flavonoids, carotenoids, and polysaccharides was assessed using spectrophotometric methods. Methanol extracts from GB were examined for their antioxidant, enzyme inhibitory (α-amylase, α-glucosidase, acetylcholinesterase and tyrosinase) and antibacterial activities. Despite significant variations among samples from different locations, the results confirmed that GB are a valuable source of dietary fiber and protein and are characterized by favorable fatty acid profiles. Phytochemical analysis revealed that ß-sitosterol, Δ5-avenasterol, and 24-methyldesmosterol are the predominant sterols and caffeic acid, gallic acid, quercetin and rutin are the main phenols. All GB samples showed both antioxidant and mild antimicrobial activity. A dose-dependent anti-enzymatic activity (IC50 ranging 1.68-6.88 mg/mL) was demonstrated. The results support further promotion of GB cultivation in Serbia and further investigations on their potential applications in various industries.

Comparative analysis of Ag NPs functionalized with olive leaf extract and oleuropein and toxicity in human trophoblast cells and peripheral blood lymphocytes.

Dry olive leaf extract (DOLE) and its active component oleuropein (OLE) were applied as reducing and stabilizing agents to prepare colloidal 20-25 nm silver nanoparticles (Ag NPs). The Ag NPs were characterized using transmission electron microscopy, X-ray diffraction analysis, and absorption spectroscopy. The cytotoxic actions of coated Ag NPs, and their inorganic and organic components, were examined against trophoblast cells and human peripheral blood lymphocytes (PBLs), Gram-positive, Gram-negative bacteria, and yeast. The genotoxic potential was evaluated in PBLs in vitro with the comet assay. Ag/DOLE and Ag/OLE induced cytotoxic effects in both types of cells after 24 h exposure when silver concentrations were 0.025-0.2 mM. However, the most pronounced cytotoxicity exhibits Ag/OLE. Both colloids also caused reduced ROS production in both cell types at 0.1 mM and 0.2 mM, while bare Ag NPs did not alter ROS levels at any of the conditions. Functionalized Ag/DOLE and Ag/OLE did not show genotoxic effects in PBLs, while bare AgNPs increased DNA damage significantly only at 0.2 mM. Regarding the antimicrobial effects, the Ag/OLE had MIC values for all evaluated microorganisms from 0.0625 to less than 0.0312 mM. Also, the antimicrobial effect of Ag/DOLE was significantly higher on Gram-negative bacteria and yeast than on Gram-positive bacteria. Obtained results indicate that Ag/OLE induced the most pronounced biological effects, beneficial for its application as an antimicrobial agent, but with potential risks from exposure to high concentrations that could induce cytotoxicity in healthy human cells.

Staphylococcal biofilm on wedding rings worn by laboratory workers.

Hands of healthcare workers play essential role in the spreading of antimicrobial-resistant microorganisms in and out of the healthcare settings. Less is known about the role of laboratory workers (LWs). The aim of our study was to evaluate the presence of biofilm-forming staphylococci on the surface of jewelry rings of LWs and their antimicrobial susceptibility pattern.A total of 79 LWs from eight different microbiology laboratories that process and analyze specimens from the tertiary care hospitals in Belgrade, Serbia participated in the study. The study was reviewed and approved by the institutional review boards at hospitals. Samples were taken after hand washing. Bacteria on LWs wedding rings were detected with the rolling method, and further analyzed in order to determine the number of colony forming unit (CFU) per ring, species of bacteria and their antimicrobial susceptibility pattern, methicillin resistance and biofilm-producing capacity in vitro.Staphylococci were recovered from 60.8% of wedding rings. All strains produced biofilm (25% weak, 56.2% moderate and 18.8% large amount), with significant difference between species (P < 0.001). Staphylococcus aureus and Staphylococcus epidermidis formed the largest amount of biofilm and had the largest number of CFU per ring. Staphylococci were most commonly resistant to penicillin (66.7%), tetracycline (50.0%), and erythromycin (45.8%); 41.7% of isolates was multidrug resistant and mecA gene was detected in five strains. All strains were susceptible to linezolid, vancomycin, teicoplanin and tigecycline.Staphylococci colonize LWs wedding rings, form biofilm on it, have multidrug resistant phenotype and/or carry mecA gene, representing a significant reservoir for the spreading of microorganisms and resistance. As far as we know, our study is the first that address this topic in laboratory workers.

Phytochemical Investigation of Cuscuta campestris Yunck. Stem Extract and Evaluation of Its Bioherbicidal Effect on Amaranthus retroflexus L. and Portulaca oleracea L.

This study focused on characterizing chemically and evaluating in vitro allelopathic and bioherbicidal potential of secondary metabolites extracted from the stem of Cuscuta campestris in seed germination, early seedling growth and early plant growth of Amaranthus retroflexus and Portulaca oleracea. The combined effects of stem extract and a reduced dose of herbicide metribuzin were also examined. Plant extract contained 17 phenolic compounds and the most abundant phenols were flavonoids: quercetin, (+)-catechin, daidzin, luteolin, and rutin. The seeds of P. oleracea were less sensitive than the seeds of A. retroflexus. The seed bioassay confirmed the inhibitory effect of stem extract on germination and early growth of both weed seedlings at concentrations of 0.75 % and 1 %, and a minor inhibitory effect in the plant bioassay. On the other hand, a synergy of C. campestris stem extract and metribuzin was revealed, as their combination achieved better results in the control of both weed species. Based on obtained data C. campestris stem extract could be a potential source of natural-based weed control molecules.

Non-destructive estimation of weed response to bleaching herbicides by Raman spectroscopy.

The aim of our study was to evaluate the use of Raman spectroscopy for pre-diagnostic estimation of weed response to bleaching herbicides. Model plants were Chenopodium album and Abutilon theophrasti treated with mesotrione (120 g a.i. ha-1). Raman single-point measurements were taken 1, 2, 3, and 7 days after herbicide application from different points on the leaves. Principal component analysis (PCA) was carried out on data normalized by the highest intensity band at 1522 cm-1 and using spectral region from 950 to 1650 cm-1 comprising mainly contributions of carotenoids. The carotenoids by intensive band at ∼1522 cm-1 and bands with lower intensity at ∼1155 and 1007 cm-1 in treated plants were confirmed. According to PC1 (the first principal component) and PC2 (the second principal component), the highest intensity bands responsible for treatment differentiation in C. album could be assigned to chlorophyll, lignin, and carotenes. According to PC1 in A. theophrasti leaves the treatment differences could be observed 7 days after mesotrione treatment and PC2 gave a clear separation between all control and treated leaf samples. Raman spectroscopy may be a good complement to invasive analytical methods, in assessing the plant abiotic stress induced by bleaching herbicides.

Curcumin Loaded PEGylated Nanoemulsions Designed for Maintained Antioxidant Effects and Improved Bioavailability: A Pilot Study on Rats.

The current study describes the experimental design guided development of PEGylated nanoemulsions as parenteral delivery systems for curcumin, a powerful antioxidant, as well as the evaluation of their physicochemical characteristics and antioxidant activity during the two years of storage. Experimental design setup helped development of nanoemulsion templates with critical quality attributes in line with parenteral application route. Curcumin-loaded nanoemulsions showed mean droplet size about 105 nm, polydispersity index <0.15, zeta potential of -40 mV, and acceptable osmolality of about 550 mOsm/kg. After two years of storage at room temperature, all formulations remained stable. Moreover, antioxidant activity remained intact, as demonstrated by DPPH (IC50 values 0.078-0.075 mg/mL after two years) and FRAPS assays. In vitro release testing proved that PEGylated phospholipids slowed down the curcumin release from nanoemulsions. The nanoemulsion carrier has been proven safe by the MTT test conducted with MRC-5 cell line, and effective on LS cell line. Results from the pharmacokinetic pilot study implied the PEGylated nanoemulsions improved plasma residence of curcumin 20 min after intravenous administration, compared to the non-PEGylated nanoemulsion (two-fold higher) or curcumin solution (three-fold higher). Overall, conclusion suggests that developed PEGylated nanoemulsions present an acceptable delivery system for parenteral administration of curcumin, being effective in preserving its stability and antioxidant capacity at the level highly comparable to the initial findings.

Formulation of topical acidic products and acidification of the skin - Contribution of glycolic acid.

OBJECTIVE: The acidic skin pH is one of the regulating factors of skin barrier homeostasis. Topical products as extrinsic factors which influence skin pH could be used for acidification of the skin and consequent beneficial effect. To formulate stabile and safe topical emulsion product with low pH is on-going challenge and areas interesting to explore are related to the effect of acidic products on the skin pH together with development of protocols for these studies. Aim of our work was to investigate formulations of acidic topical products with glycolic acid (GA) stabilized with long chain alkyl polyglucoside emulsifier, in regard to the specific colloidal structure of the vehicle, together with effect of products with different concentration of acidic active on skin pH. METHODS: Investigated formulations were basic vehicle and two creams with glycolic acid (concentration 2 and 10 wt%). Microstructure was investigated by polarization microscopy, Raman spectral imaging, thermal analysis and rheological measurements. Effects on the skin were assessed by measurement of biophysical skin parameters in vivo studies (5-hour, 24-hour and 7-days). In vitro screening of antimicrobial activity was performed against bacteria Staphylococcus epidermidis. RESULTS: Polarization micrographs and Raman images have shown that GA does not disturb the specific colloidal structure. Together with rheological and thermal analysis obtained results have shown that GA in higher concentrations contributes to vehicles' lamellar structure. In 5-hour study the mean values of skin pH ranged from 3.98-4.25 and 3.89-4.10 after application of products with smaller and higher GA concentration. GA samples lowered skin surface pH to 5 and less in 24-hour and 7-day study, with stronger effect of sample with more GA. Sample with 10% of GA had significant inhibitory effect on growth of S. epidermidis in 1:1 concentration. CONCLUSIONS: Investigated APG emulsifier could be used as a stabilizer for acidic topical products with GA which are characterized by satisfactory safety profile. Topical products induce acidification of the skin after short- and long-term application without barrier impairment or sign of irritation. Acidification of the skin depends on presence of ingredients which are proton donors and their concentrations.

OBJECTIF: Le pH acide de la peau est l'un des facteurs de régulation de l'homéostasie de la barrière cutanée. Les produits topiques pourraient être utilisés en tant que facteurs extrinsèques d'influence du pH cutané pour permettre l'acidification de la peau et obtenir l'effet bénéfique qui en résulte. Formuler des émulsions topiques stables et sûres à faible pH représente un défi constant et les domaines d'étude dignes d'intérêt portent sur l'effet des produits acides sur le pH cutané et sur l'élaboration de protocoles pour ces études. L'objectif de notre travail était d'étudier des formulations de produits topiques acides à base d'acide glycolique (AG) stabilisé à l'aide d'un émulsionnant à base d'alkylpolyglucoside (APG) à longue chaîne, par rapport à la structure colloïdale spécifique de l'excipient, ainsi que l'effet des produits à différentes concentrations d'acide actif sur le pH cutané. MÉTHODES: Les formulations étudiées étaient un excipient de base et deux crèmes à base d'acide glycolique (concentration égale à 2 % et 10 % de la fraction massique). La microstructure a été étudiée par microscopie à polarisation, par spectroscopie Raman, par analyse thermique et par mesures rhéologiques. Les effets cutanés ont été évalués par la mesure des paramètres cutanés biophysiques dans des études in vivo (5 heures, 24 heures et 7 jours). Un dépistage in vitro de l'activité antimicrobienne a été effectué sur la bactérie Staphylococcus epidermidis. RÉSULTATS: Les micrographies après polarisation et les images obtenues par spectroscopie Raman ont montré que l'AG ne perturbe pas la structure colloïdale spécifique. Avec les analyses rhéologique et thermique, les résultats obtenus ont montré que l'AG à des concentrations plus élevées joue un rôle dans la structure lamellaire des excipients. Dans l'étude de 5 heures, les valeurs moyennes du pH cutané allaient de 3,98 à 4,25 et de 3,89 à 4,10 après l'application des produits présentant une concentration d'AG plus faible et plus élevée. Grâce aux échantillons d'AG, le pH de la surface cutanée a diminué, passant ainsi à une valeur de 5 et à des valeurs inférieures dans les études de 24 heures et de 7 jours, et l'échantillon contenant davantage d'AG a eu un effet plus important. L'échantillon contenant 10 % d'AG a eu un effet inhibiteur significatif sur la croissance de la bactérie S. epidermidis à une concentration de 1:1. CONCLUSION: L'émulsionnant à base d'APG étudié pourrait être utilisé comme stabilisateur pour les produits topiques acides à base d'AG caractérisés par un profil d'innocuité satisfaisant. Les produits topiques induisent une acidification de la peau après une application à court et à long terme sans altération de la barrière cutanée ou signe d'irritation. L'acidification de la peau dépend de la présence de donneurs de proton parmi les composants et de leurs concentrations.

Antimicrobial activity of novel chalcones and modulation of virulence factors in hospital strains of Acinetobacter baumannii and Pseudomonas aeruginosa.

Acinetobacter baumannii and Pseudomonas aeruginosa are frequent multiresistant nosocomial pathogens that cause wound and pulmonary infections in hospitalized patients. As being increasingly resistant to most clinically available antibiotics, there is a constant need for exploration of new substances that could kill them or inhibit their growth, or alternatively inhibit some of their essential virulence factors. Chalcones are chemical compounds with well-documented antimicrobial potential. The aim of this study was to examine effectiveness of four newly-synthesized chalcones against the multiresistant clinical strains of A. baumannii and P. aeruginosa. Antibacterial activity of chalcones was investigated with broth-microdilution test and time-dependent killing assay. Synergistic effects of tested compounds with antibiotics (meropenem, amikacin and ciprofloxacin) were determined by checkerboard assay. The effects of chalcones on expression of virulence factors in P. aeruginosa (pyocyanin production, swimming and swarming motility) and A. baumannii (twitching and surface-associated motility), along with their biofilm production, were also examined. The obtained results indicate substantial antimicrobial activity of the tested chalcones (MICs = 100-175 µg/mL) and several synergistic interactions with antibiotics, as well as notable reduction in expression of all investigated virulence factors. These promising results may constitute a good basis for further research.

The response of Chenopodium album L. and Abutilon theophrasti Medik. to reduced doses of mesotrione.

The application of minimal doses of herbicides is very popular due to concerns about the negative impacts of herbicides on the environment and public health. Studies were conducted to estimate the possibility of using quick and non- destructive methods to investigate Chenopodium album L. and Abutilon theophrasti Medik. response to mesotrione. The studies were conducted in a controlled environment to determine the response of C. album and A. theophrasti to mesotrione using dose-response curves created based on plant dry weight, chlorophyll fluorescence parameters and chlorophyll content. The obtained effective dose values showed that the studied weeds were susceptible to reduced doses of mesotrione. ED95 values estimated for both species for dry weight and chlorophyll fluorescence parameters were lower than the recommended dose rate (120 g a.i. ha-1), with less than 85 g a.i. ha-1 needed to achieve a reduction of 95%, compared with untreated plants, while ED95 value (A. theophrasti: 182 g a.i. ha-1 and C. album: 180 g a.i. ha-1) for chlorophyll content for both species was above the recommended dose rates. Consequently, dry weight and the chlorophyll fluorescence parameters are suitable for estimating the plant response to mesotrione, while chlorophyll content is not.

Antibiofilm effects of amoxicillin-clavulanic acid and levofloxacin in patients with chronic rhinosinusitis with nasal polyposis.

PURPOSE: Microbial biofilms have been implicated in the pathogenesis of chronic rhinosinusitis with nasal polyposis (CRSwNP). The aim of our study was to evaluate in vitro effects of amoxicillin-clavulanic acid and levofloxacin on biofilm formation by bacterial species isolated from sinus tissue in patients with CRSwNP. METHODS: The sinus mucosal specimens were harvested from the upper parts and roof of ethmoid cavity of 48 patients with CRSwNP. Each sample was washed thoroughly in three separate beakers of sterile saline to remove any planktonic bacteria and further subjected to microbiology analysis. The biofilm-forming capacity of isolated strains was detected by microtiter-plate method and the effects of subinhibitory (1/2× to 1/16× MIC) and suprainhibitory concentrations (4, 8, 16, 32, and 64 µg/ml) of amoxicillin-clavulanic acid and levofloxacin on biofilm production were investigated. RESULTS: Bacterial strains were isolated in 42 (87.5%) patients: one microorganism in 80.9% and two microorganisms in 19.1% of patients. The most prevalent bacteria in CRSwNP biofilms were Staphylococcus epidermidis (34%) and S. aureus (28%) followed by S. haemolyticus (12%), Pseudomonas aeruginosa (8%), Moraxella catarrhalis (6%), Streptococcus pneumoniae (6%), and other staphylococci (6%). Subinhibitory concentrations of amoxicillin-clavulanic acid and levofloxacin significantly reduced biofilm formation (p < 0.01 and p < 0.05, respectively), with better efficacy of amoxicillin-clavulanic acid (1/2-1/8× MIC) on staphylococci and levofloxacin (1/2- 1/4× MIC) on M. catarrhalis and P. aeruginosa biofilm formation. Suprainhibitory concentrations of both tested antibiotics (4-64 µg/ml) significantly eradicated mature biofilms of staphylococci (p < 0.01). The effect of levofloxacin on eradication of staphylococcal biofilms was more noticeable, compared to the effect of amoxicillin-clavulanic acid (p < 0.01). Suprainhibitory concentrations of both tested antibiotics had no effect on eradication of previously formed M. catarrhalis and P. aeruginosa biofilms (p > 0.05). CONCLUSIONS: The amoxicillin-clavulanic acid and levofloxacin are shown to be potent antibiofilm agents in patients with CRSwNP. The effects of tested compounds depend on bacterial species and the volume of formed biofilm.

The Effect of Vacuum-Assisted Closure Therapy on Methicillin-Resistant Staphylococcus aureus Wound Biofilms.

Biofilm-associated wound infections are a major global health issue, and methicillin-resistant Staphylococcus aureus (MRSA) is among the greatest therapeutic challenges. Vacuum-assisted closure (VAC) therapy is now being revisited as an alternative treatment for both acute and chronic wounds. However, data supporting the concept of its antibiofilm effect remain limited. Using quantitative biofilm-forming assay and a range of genotypic methods (spa, SCCmec, and agr typing), study authors showed that VAC therapy can significantly prevent biofilm formation (P < .01) of a range of MRSA wound isolates differing widely in their biofilm-forming abilities and genetic background. The best effect was presented on CC5-MRSA-SCCmecI-agrII, a dominant MRSA clone among wound isolates worldwide. An assessment of effects of different protocols on dressing changes (1 or 2 times per week) demonstrated significantly greater antibiofilm activity (P < .05) of 3-day dressing changes. These findings support the use of VAC therapy as a topical antibiofilm treatment for the effective management of wound healing.

Antibiofilm effects of topical corticosteroids and intranasal saline in patients with chronic rhinosinusitis with nasal polyps depend on bacterial species and their biofilm-forming capacity.

Microbial biofilms have been implicated in the pathogenesis of chronic rhinosinusitis with nasal polyposis (CRSwNP). Intranasal application of corticosteroids and saline is a reliable option for their management. The aim of our study was to evaluate in vitro antibiofilm effects of corticosteroids and isotonic and hypertonic nasal saline in CRSwNP patients. The sinus mucosal specimens were harvested from the ethmoid cavity of 48 patients with CRSwNP and further subjected to hematoxylin-eosin staining and microbiology analysis. The biofilm-forming capacity of isolated bacterial strains was detected by microtiter-plate method and the effects of therapeutic doses of mometasone, fluticasone, isotonic and hypertonic saline on biofilm production were investigated. Bacterial strains were isolated in 42 (87.5%) patients: one organism in 34 (80.9%) and two organisms in 8 (19.1%). Staphylococcus epidermidis (34%) and Staphylococcus aureus (28%) were the most prevalent bacteria in biofilms of CRSwNP patients. Corticosteroids and saline solutions significantly reduced biofilm formation (p < 0.01 and p < 0.05, respectively) with better efficacy of fluticasone and isotonic nasal saline. Treatment with fluticasone, mometasone, isotonic and hypertonic nasal saline completely prevented biofilm production in 66, 50, 84 and 38% of bacterial strains, respectively. The most significant density reduction was observed in biofilm formed by Staphylococcus aureus, Pseudomonas aeruginosa and Streptococcus pneumoniae compared to other bacterial species (p < 0.01, p < 0.05, p < 0.05, respectively). The antibiofilm effects of corticosteroids and saline solutions also greatly depended on bacterial biomass (p < 0.05), with the most significant effect on high compared to small amount of formed biofilm. The topical steroids and nasal saline are shown to be potent antibiofilm agents in patients with CRSwNP. The effects of tested compounds depend on bacterial species and volume of formed biofilm.

Effect of Cuscuta campestris parasitism on the physiological and anatomical changes in untreated and herbicide-treated sugar beet.

The effects of field dodder on physiological and anatomical processes in untreated sugar beet plants and the effects of propyzamide on field dodder were examined under controlled conditions. The experiment included the following variants: N-noninfested sugar beet plants (control); I - infested sugar beet plants (untreated), and infested plants treated with propyzamide (1500 g a.i. ha-1 (T1) and 2000 g a.i. ha-1(T2)). The following parameters were checked: physiological-pigment contents (chlorophyll a, chlorophyll b, total carotenoids); anatomical -leaf parameters: thickness of epidermis, parenchyma and spongy tissue, mesophyll and underside leaf epidermis, and diameter of bundle sheath cells; petiole parameters: diameter of tracheid, petiole hydraulic conductance, xylem surface, phloem cell diameter and phloem area in sugar beet plants. A conventional paraffin wax method was used to prepare the samples for microscopy. Pigment contents were measured spectrophotometrically after methanol extraction. All parameters were measured: prior to herbicide application (0 assessment), then 7, 14, 21, 28 and 35 days after application (DAA). Field dodder was found to affect the pigment contents in untreated sugar beet plants, causing significant reductions. Conversely, reduction in the treated plants decreased 27% to 4% for chlorophyll a, from 21% to 5% for chlorophyll b, and from 28% to 5% for carotenoids (T1). Also, in treatment T2, reduction decreased in infested and treated plants from 19% to 2% for chlorophyll a, from 21% to 2% for chlorophyll b, from 23% to 3% for carotenoids and stimulation of 1% and 2% was observed 28 and 35 DAA, respectively. Plants infested (untreated) by field dodder had lower values of most anatomical parameters, compared to noninfested plants. The measured anatomical parameters of sugar beet leaves and petiole had significantly higher values in noninfested plants and plants treated with propyzamide than in untreated plants. Also, the results showed that propyzamide is an adequate herbicide for control of field dodder at the stage of early infestation.

Biofilm formation on tympanostomy tubes depends on methicillin-resistant Staphylococcus aureus genetic lineage.

Bacterial biofilm formation has been implicated in the high incidence of persistent otorrhoea after tympanostomy tube insertion. The aim of the study was to investigate whether biofilm formation on tympanostomy tubes depends on the genetic profile of methicillin-resistant Staphylococcus aureus (MRSA) strains. Capacity of biofilm formation on fluoroplastic tympanostomy tubes (TTs) was tested on 30 MRSA strains. Identification and methicillin resistance were confirmed by PCR for nuc and mecA genes. Strains were genotypically characterised (SCCmec, agr and spa typing). Biofilm formation was tested in microtiter plate and on TTs. Tested MRSA strains were classified into SCCmec type I (36.7 %), III (23.3 %), IV (26.7 %) and V (13.3 %), agr type I (50 %), II (36.7 %) and III (13.3 %), and 5 clonal complexes (CCs). All tested MRSA strains showed ability to form biofilm on microtiter plate. Capacity of biofilm formation on TTs was as following: 13.3 % of strains belonged to the category of no biofilm producers, 50 % to the category of weak biofilm producers and 36.7 % to moderate biofilm producers. There was a statistically significant difference between CC, SCCmec and agr types and the category of biofilm production on TTs tubes (p < 0.001): CC5, SCCmecI type and agrII type with a moderate amount of biofilm, and CC8 and agrI type with a low amount of biofilm. Biofilm formation by MRSA on TTs is highly dependent on genetic characteristics of the strains. Therefore, MRSA genotyping may aid the determination of the possibility of biofilm-related post-tympanostomy tube otorrhea.

Combined metabolome and transcriptome profiling provides new insights into diterpene biosynthesis in S. pomifera glandular trichomes.

BACKGROUND: Salvia diterpenes have been found to have health promoting properties. Among them, carnosic acid and carnosol, tanshinones and sclareol are well known for their cardiovascular, antitumor, antiinflammatory and antioxidant activities. However, many of these compounds are not available at a constant supply and developing biotechnological methods for their production could provide a sustainable alternative. The transcriptome of S.pomifera glandular trichomes was analysed aiming to identify genes that could be used in the engineering of synthetic microbial systems. RESULTS: In the present study, a thorough metabolite analysis of S. pomifera leaves led to the isolation and structure elucidation of carnosic acid-family metabolites including one new natural product. These labdane diterpenes seem to be synthesized through miltiradiene and ferruginol. Transcriptomic analysis of the glandular trichomes from the S. pomifera leaves revealed two genes likely involved in miltiradiene synthesis. Their products were identified and the corresponding enzymes were characterized as copalyl diphosphate synthase (SpCDS) and miltiradiene synthase (SpMilS). In addition, several CYP-encoding transcripts were identified providing a valuable resource for the identification of the biosynthetic mechanism responsible for the production of carnosic acid-family metabolites in S. pomifera. CONCLUSIONS: Our work has uncovered the key enzymes involved in miltiradiene biosynthesis in S. pomifera leaf glandular trichomes. The transcriptomic dataset obtained provides a valuable tool for the identification of the CYPs involved in the synthesis of carnosic acid-family metabolites.

Methicillin-resistant Staphylococcus aureus biofilm formation on dacryocystorhinostomy silicone tubes depends on the genetic lineage.

PURPOSE: The aim of this study was to investigate biofilm formation on silicone tubes by genetically diverse methicillin-resistant Staphylococcus aureus (MRSA) strains. METHODS: Capacity of biofilm formation on dacryocystorhinostomy silicone tubes was tested on 30 MRSA strains. Identification and methicillin resistance were confirmed by PCR for nuc and mecA genes. Strains were genotypically characterised (SCCmec, agr and spa typing). Biofilm formation was tested in microtiter plate and on silicone tubes. RESULTS: Tested MRSA strains were classified into SCCmec type I (33.3%), II (3.3%), III (20.0%), IV (26.7%) and V (16.7%), agr type I (56.7%), II (36.7%) and III (6.6%), and eight spa clonal complexes (CCs). All tested MRSA strains showed ability to form biofilm on microtiter plate. Capacity of biofilm formation on silicone tubes was as follows: 33.3% of strains belonged to the category of low biofilm producers, and 66.7% to moderate biofilm producers. There was statistically significant correlation between spa CC and the category of biofilm production on silicone tubes (p = 0.01): CC5 and CC45 with moderate amount of biofilm, and CC8 with low amount of biofilm. A moderate amount of biofilm formed on silicone tubes correlated with agr type II MRSA strains (p = 0.008). CONCLUSIONS: Biofilm formation by MRSA on silicone tubes is highly dependent on genetic characteristics of the strains. Therefore, MRSA genotyping may aid the determination of the possibility of biofilm-related ocular device infections. Genotyping and biofilm quantification may be helpful in determining when decolonisation and cohort isolation are required to prevent device-related infections.

Inhibitory Effect of Newly-Synthesized Chalcones on Hemolytic Activity of Methicillin-Resistant Staphylococcus aureus.

Pathogenicity of methicillin-resistant Staphylococcus aureus (MRSA) is associated with a broad spectrum of virulence factors, amongst which is α-hemolysin. The aim of this study was to investigate the effect of three newly-synthesized chalcones (1,3- Bis-(2-hydroxy-phenyl)-propenone, 3-(3-Hydroxy-phenyl)-1-(2-hydroxy-phenyl)-propenone and 3-(4-Hydroxy-phenyl)-1-(2-hydroxy-phenyl)-propenone) on a-hemolysin production of clinical isolates of MRSA. Subinhibitory concentrations of the tested compounds reduced hemolytic activity of MRSA strains, with almost complete abolishment of hemolysis at concentrations in the range of 1/2-1/4 x MIC (25-12.5 µg/ml). In conclusion, newly-synthesized chalcones tested in this study showed potent inhibitory activity on α-hemolysin production of multiresistant and genetically diverse MRSA strains.

Antibacterial activity of three newly-synthesized chalcones & synergism with antibiotics against clinical isolates of methicillin-resistant Staphylococcus aureus.

BACKGROUND & OBJECTIVES: Multidrug-resistance of methicillin-resistant Staphylococcus aureus (MRSA) is a serious therapeutical problem. Chalcones belong to a group of naturally occurring flavonoids, usually found in various plant species, and have potent antibacterial, antiviral and antifungal activities. The goal of this study was to evaluate the antibacterial effect of three newly-synthesized chalcones against clinical isolates of MRSA, and their synergism with ß-lactam and non-ß-lactam antibiotics. METHODS: Antimicrobial activity of the three newly-synthesized chalcones was tested against 19 clinical isolates of MRSA and a laboratory control strain of MRSA (ATCC 43300). The synergism with ß-lactams: cefotaxime (CFX), ceftriaxone (CTX), and non-ß-lactam antibiotics: ciprofloxacin (CIP), gentamicin (GEN) and trimethoprim/sulphamethoxazole (TMP-SMX) was investigated by checkerboard method. RESULTS: All evaluated compounds showed significant anti-MRSA activity with MIC values from 25-200 µg/ml. Observed synergism with antibiotics demonstrated that chalcones significantly enhanced the efficacy of CIP, GEN and TMP-SMX. INTERPRETATION & CONCLUSIONS: Our study demonstrated that three newly-synthesized chalcones exhibited significant anti-MRSA effect and synergism with non-ß-lactam antibiotics. The most effective compound was 1,3-Bis-(2-hydroxy-phenyl)-propenone. Our results provide useful information for future research of possible application of chalcones in combination with conventional anti-MRSA therapy as promising new antimicrobial agents.

Biofilm-producing Bacteria and Quality of Life after Endoscopic Sinus Surgery in Patients with Chronic Rhinosinusitis with Nasal Polyposis.

BACKGROUND: Chronic rhinosinusitis (CRS) is one of the most common health disorders in humans and has a major impact on health-related quality of life (HRQoL). Of the many factors contributing to the etiology of CRS, less is known about the correlation between CRS and bacterial biofilms and their impact on HRQoL. OBJECTIVE: The aim of this prospective study was to investigate the relationship between biofilm-producing bacteria and patients' objective findings and HRQoL. METHODS: Forty-eight patients with CRSwNP were enrolled in a 12-month prospective study. The Lund-Mackay (LM) CT and endoscopic Lund-Kennedy (LK) scores were obtained before endoscopic sinus surgery (ESS), and patients completed the HRQoL instruments: the 22-item Sinonasal Outcome Test (SNOT-22), the 36-item Short Questionnaire (SF-36), and the visual analog scale (VAS). A sinus culture was obtained at ESS, bacteria were isolated, and in vitro quantification of the biofilm was performed. The LK score and HRQoL were determined postoperatively at months 1, 3, 6, and 12. RESULTS: The most common bacterial isolates in patients with CRSwNP were Staphylococcus aureus (28%), coagulase-negative staphylococci (52%), and Pseudomonas aeruginosa (8%). Preoperatively, the highest LM and LK scores were found in patients with strong biofilm producers. Postoperative LK scores were significantly reduced in all patients. Postoperative VAS scores were significantly reduced from month 1 to month 12 postoperatively. Patients with strong biofilm producers had significantly worse nasal blockage, secretion, headache, facial pressure and pain, and loss of smell preoperatively, compared to patients with low biofilm producers. The most significant reduction in preoperative scores SNOT-22 and SF-36 (excluding physical functioning) was seen in patients with S. aureus and P. aeruginosa. CONCLUSIONS: Patients with strong biofilm producers had higher LK and LM scores preoperatively, and greater improvement in LK and HRQoL scores postoperatively. Microbiologic surveillance of all CRS patients is recommended.