Smaller Zones Of Inhibition Research Articles

Investigating in-vitro antimicrobial activity, biosynthesis, and characterization of silver nanoparticles, zinc oxide nanoparticles, and silver-zinc oxide nanocomposites using Pistacia Atlantica Resin

In the present study, a fast and straightforward method was presented for the preparation of silver nanoparticles (AgNPs), zinc oxide nanoparticles (ZnNPs), and silver-zinc oxide nanocomposites (Ag-ZnNPs). Biosynthesis was carried out using resin extraction from Pistacia Atlantica as a reductant and capping agent. In-vitro antimicrobial activities of these particles, silver nitrate (AgNO3), and zinc nitrate (Zn (NO3)2) were also evaluated in comparison with resin extracts. Synthesis of the nanoparticles and nanocomposites was characterized and confirmed by ultraviolet-visible spectroscopy (UV–vis), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM) equipped with an energy dispersive spectroscopy (EDS) and transmission electron microscope (TEM). Then, antimicrobial activity was tested against Klebsiella pneumonia, Escherichia coli, Staphylococcus aureus, and Proteus mirabilis using the agar well diffusion method. Maximum inhibition zones were observed for resin-AgZnNPs and resin-ZnNPs (21.1 ± 0.002 mm), demonstrating their antibacterial activity, while Zn (NO3)2 had the smallest inhibition zone (5.4 ± 0.06 mm). These results are promising in terms of their potential ability to be used against pathogenic bacteria.

Evaluation of Drug Resistance Before and After Biofilm Formation of Bacteria Causing Wound Infection and Detection of Their Protease Activity

Background: Wound infection is a highly common problem in hospital settings, where microbes are often resistant and difficult to treat due to rapid exposure to antibiotics. While treating wound infection, bacteria often enter the deep tissue; as therapy needs long exposure time, bacteria have sufficient time to develop biofilm, which makes them much more resistant to antibiotics. Objectives: The current study was performed to identify wound-infecting bacteria and determine their protease production activity. Methods: The ability to produce biofilm was evaluated by the Congo red agar and tube methods. Antibiotic resistance pattern was assessed before and after biofilm formation to detect the changes in resistance due to biofilm formation. Results: We identified Pseudomonas aeruginosa, Proteus mirabilis, Proteus vulgaris, Corynebacterium xerosis, Alcaligenes faecalis, Bacillus cereus, Escherichia coli, Acinetobacter spp., Klebsiella pneumoniae, Staphylococcus spp., Shigella spp., and Salmonella spp. in 20 wound samples, among which about 10 isolates were found to be biofilm producers. Almost all the biofilm producers showed complete resistance or a much smaller inhibition zone. Conclusions: Pathogenic bacteria can be more difficult to eradicate by antibiotic treatment if they are able to produce biofilm; thus, it is essential to prevent biofilm formation.

Possible Tracheal Relaxant and Antimicrobial Effects of the Essential Oil of Ethiopian Thyme Species (Thymus serrulatus Hochst. ex Benth.): A Multiple Mechanistic Approach.

The genus Thymus is traditionally used for the treatment of hyperactive airways complaints. The purpose of the current study is to investigate the potential tracheal relaxant effect and possible mechanism(s) of the essential oil of Thymus serrulatus (TS Oil) in isolated guinea pig tracheal tissues. The essential oil was obtained from the fresh erial parts of Thymus serrulatus, and its phyto-components were identified by GC-MS analysis. Guinea pig tracheal preparations were used for testing the tracheal relaxant effect of TS Oil with the determination of the mechanism(s) involved in this relaxation. GC-MS findings reveal that terpenes, fragrance constituents, saponins, and higher fatty acids are present in TS Oil. In isolated guinea pig trachea, TS Oil inhibited carbachol (CCh, 1 µM) and K+ (80 mM)-induced contractions in a pattern similar to that of dicyclomine. TS Oil, at 0.3 mg/ml, shifted parallel CCh-curves towards the right, followed by a non-parallel shift at higher concentration (1 mg/ml), thus suppressing maximum response in the same manner as produced by dicyclomine. Pretreatment of tissues with TS Oil (1 and 3 mg/ml) also produced a rightward shift of Ca++ concentration-response curves (CRCs) in the same manner as caused by verapamil. Further, TS Oil at low concentrations (0.3 and 1 mg/ml) shifted isoprenaline-induced inhibitory CRCs towards the left and increased cAMP levels in isolated tracheal homogenates similar to papaverine, a phosphodiesterase (PDE) inhibitor. In the antimicrobial assay performed by the agar well diffusion method, TS Oil was found most active against Candida albicans and Staphylococcus aureus where the zone of inhibition measured was 28 mm. Additionally, there was little difference between standard strains of gram-positive and gram-negative bacteria. However, methicillin-resistant S. aureus (MRSA) showed a small zone of inhibition as compared to standard strains (22 mm). From these results, it can be concluded that the essential oil of T. serrulatus has the potential to produce antimicrobial effects while causing tracheal relaxation mediated possibly by anticholinergic effects, Ca++ channel blockade, and PDE inhibition whereas additional mechanism(s) cannot be ruled out.

Antibacterial Activity Test of the Ethanol in Leaves Extract of Senduduk (Melastoma malabathricum L.) Against Escherichia coli and Staphylococcus aureus

Senduduk (Melastoma malabathricum L.) is one of the wild plants used as traditional medicine. Senduduk leaves are used as a medicine for sprue, boils, diarrhea and smallpox. The purpose of this study was to determine the antibacterial activity of the ethanol extract of senduduk leaves of the against Escherichia coli and Staphylococcus aureus. Senduduk leaves extracted by maceration using 96% ethanol solvent. Antibacterial activity testing is carried out using the diffusion method using paper discs.This experiment was repeated three times using concentrations of 20%, 40%, 60% and 80%.Ethanol extract of the senduduk leaves contains flavonoids, saponins, tannins and steroids/triterpenoids. The test results showed that the ethanol extract of the leaves has antibacterial activity against Escherichia coli and Staphylococcus aureus which is characterized by the inhibition zone formed around the disc paper. In Escherichia coli bacteria the smallest inhibition zone at a concentration of 20% with a diameter of inhibition zone 11 mm and the largest diameter of the inhibitory zone at a concentration of 80% with a diameter of inhibition zone 19 mm. whereas for the smallest inhibitory zone Staphylococcus aureus bacteria at a concentration of 20% with an inhibition zone diameter of 12.6 mm and the largest inhibitory zone dameter at a concentration of 80% with a diameter of the inhibitory zone 21,3 mm.The results of the study concluded that the ethanol extract of Senduduk leaves has antibacterial activity against Escherichia coli and Staphylococcus aureus.

Comparative Antibacterial Activity and Quality Assessment of Essential Oils from Different Producers Against Oral Pathogens

Abstract The aim of the study is to evaluate antibacterial properties of commercial essential oils (Oregano, Black pepper, Coriander, Cinnamon) against oral pathogens (Streptococcus mutans, Enterococcus faecalis). Nevertheless, we want to asses if the price of the essential oils (EO) which were purchased from 2 different retailers, can influence the quality of essential oil and the antimicrobial effect. Materials and methods: Essential oils from two different Producers (A-high price range, respectively B-low price range) with two opposite price ranges were purchased from local retailers. The inhibitory effect was assessed by disk diffusion. Bacterial inoculums of 0.5 McFarland units (~1.5 x 108 CFU/ml) were prepared from Streptococcus mutans Enterococcus faecalis. Muller-Hinton agar plates were inoculated with bacterial inoculums. Sterile paper disks with the diameter of 6 mm (Bioanalyse Ltd, Turkey) were dispensed on the medium surface. Five μl of essential oils were pipetted on corresponding disks. After 10 minutes (time needed for a proper diffusion of active components), the plates were incubated in normal atmosphere at 37°C. After 24 hours of incubation, the inhibition zone diameters (in millimeters) were read and noted in spreadsheet software, aside the average price in €/ml of essential oil. A cost-efficiency antibacterial activity index was also calculated.Results:With regard to EO from Producer A, the inhibition zone against Enteroccocus ranged from the weakest 14mm(Black pepper), 28mm(Coriander) to the strongest over 40 mm(Oregano and Cinnamon). With regard to volatile essential oils from Producer B, against the Enteroccocus, the smallest inhibition zone was observed for Coriander (10 mm), followed by Black pepper(11 mm); on the opposite side, the strongest inhibition zone presented both Oregano EO and Cinnamon EO (34 mm). Against S. mutans, the weakest inhibition zone showed Black pepper(6 mm), followed by Coriander EO(12 mm) and the strongest inhibition zone had Oregano EO(38 mm) and Cinnamon EO (40 mm). All the EO from the Producer A managed to successfully inhibit S. mutans growth. In both producers, Origanum vulgare EO was the most cost-efficient against E. faecalis (index=0.06 for Producer A and 0.03 for Producer B). In the case of Producer A, against S.mutans the best index was seen at Coriandrum sativum EO (0,05) and the weakest at Cinnamonum zeylanicum (0,14). In the case of Producer B, against E. faecalis, the lowest index was seen at Piper nigrum(0,13). The same pattern was seen against S. mutans, the highest index had Origanum vulgare(0,03) and the lowest Piper nigrum (0,23) Conclusions:Most of essential oils studied from both Producers, had better antibacterial effect against S. mutans compared to E. faecalis.All the EO from the Producer A managed to successfully inhibit S. mutans growth.The high price EO had a better antimicrobial effect compared to the low price EO.The strongest antimicrobial effect against E.faecalis had the high-price Oregano and Cinnamon EO and the weakest antimicrobial effect had low-price Coriander EO. Against S. mutans, the greatest efficacy had all high-price EO, and the lowest had the low-price Black pepper EO.The high price of some EO (Piper nigrum) does not make any difference regarding the antibacterial effect. Lower price EO may be still suitable in regards of antibacterial effect if considering the associated costs, even if the effect does not reach the potency of the higher-price alternatives.

PLA/metal oxide biocomposites for antimicrobial packaging application

ABSTRACT The effects of metal oxide addition in polylactic acid (PLA) film were investigated in this study. PLA/Metal Oxide biocomposites were prepared by solvent casting method. The incorporation of metal oxide resulted in no chemical structure change of neat PLA. PLA/ZnO and PLA/MgO exhibited the widest inhibition while PLA/TiO2 resulted in the smallest inhibition zone. The addition of metal oxides caused fracture and void on the surface of PLA. The addition of metal oxide into PLA films decreased the tensile strength at the concentration higher than 0.1 per hundred resin (phr). Incorporation of metal oxides accelerated the thermal degradation of PLA and tends to increase the biodegradability of PLA.

Development and Validation of an HPLC Method for the Quantitative Analysis of Bromophenolic Compounds in the Red Alga Vertebrata lanosa.

Bromophenols are a class of compounds occurring in red algae that are thought to play a role in chemical protection; however, their exact function is still not fully known. In order to investigate their occurrence, pure standards of seven bromophenols were isolated from a methanolic extract of the epiphytic red alga Vertebrata lanosa collected in Brittany, France. The structures of all compounds were determined by NMR and MS. Among the isolated substances, one new natural product, namely, 2-amino-5-(3-(2,3-dibromo-4,5-dihydroxybenzyl)ureido)pentanoic acid was identified. An HPLC method for the separation of all isolated substances was developed using a Phenomenex C8(2) Luna column and a mobile phase comprising 0.05% trifluoroacetic acid in water and acetonitrile. Method validation showed that the applied procedure is selective, linear (R2 ≥ 0.999), precise (intra-day ≤ 6.28%, inter-day ≤ 5.21%), and accurate (with maximum displacement values of 4.93% for the high spikes, 4.80% for the medium spikes, and 4.30% for the low spikes). For all standards limits of detection (LOD) were lower than 0.04 μg/mL and limits of quantification (LOQ) lower than 0.12 μg/mL. Subsequently, the method was applied to determine the bromophenol content in Vertebrata lanosa samples from varying sampling sites and collection years showing values between 0.678 and 0.005 mg/g dry weight for different bromophenols with significant variations between the sampling years. Bioactivity of seven isolated bromophenols was tested in agar diffusion tests against Staphylococcus aureus and Escherichia coli bacteria. Three compounds showed a small zone of inhibition against both test organisms at a concentration of 100 µg/mL.

A second intracellular copper/zinc superoxide dismutase and a manganese superoxide dismutase in Oxya chinensis: Molecular and biochemical characteristics and roles in chlorpyrifos stress

A second intracellular copper/zinc superoxide dismutase (icCuZnSOD2) and manganese SOD (MnSOD) were cloned and characterized in Oxya chinensis. The open reading frame (ORF) of OcicCuZnSOD2 and OcMnSOD are 462 and 672 bp encoding 153 and 223 amino acids, respectively. OcicCuZnSOD2 contains two signature sequences, one potential N-glycosylation site, and seven copper/zinc binding sites. OcMnSOD includes a mitochondria targeting sequence of 7 amino acids at N-terminal, one signature sequence, two N-glycosylation sites, and four manganese binding sites. The secondary structure and homology model of OcicCuZnSOD2 include nine β sheets, two Greek-key motifs, and one electrostatic loop. OcMnSOD contains nine α-helices and three β-sheets. Phylogenetic analysis shows that OcMnSOD is evolutionarily conserved while OcicCuZnSOD2 may be gene duplication and is paralogous to OcicCuZnSOD1. OcMnSOD expressed widely in all tissues and developmental stages. OcicCuZnSOD2 showed testis-specific expression and expressed highest in the 5th-instar nymph and the adult. The optimum temperatures and pH values of the recombinant OcicCuZnSOD2 and OcMnSOD were 40 °C and 8.0. They were stable at 25–55 °C and at pH 5.0–12.0 and pH 6.0–12.0, respectively. The activity and mRNA expression of each OcSOD were assayed after chlorpyrifos treatments. Total SOD and CuZnSOD activities first increased then declined under chlorpyrifos stress. Chlorpyrifos induced the mRNA expression and activity of OcMnSOD as a dose-dependent manner and inhibited OcicCuZnSOD2 transcription. The role of each OcSOD gene in chlorpyrifos stress was investigated using RNAi and disc diffusion assay with Escherichia coli overexpressing OcSOD proteins. Silencing of OcMnSOD significantly increased ROS content in chlorpyrifos-exposed grasshoppers. Disc diffusion assay showed that the plates with E. coli overexpressing OcMnSOD had the smaller inhibition zones around the chlorpyrifos-soaked filter discs. These results implied that OcMnSOD played a significant role in defense chlorpyrifos-induced oxidative stress.

GO/Ag2O Composite Nanostructure as an Effective Antibacterial Agent

AbstractSilver oxide nano‐particles (Ag2O NPs) are prepared by wet chemical method and impregnated with graphene oxide (GO) nano‐sheets in different wt. % ratios. The Ag2O NPs showed peaks in with the face centered cubic crystalline structure as indicated by X‐ray diffraction (XRD). The characteristic peaks of GO are also appeared in XRD patterns of GO/Ag2O composites. SEM image of pure GO nano‐sheets represented thin flexible layered structure. In GO/Ag2O hybrid structure, the Ag2O nanoparticles are randomly anchored on the surface of GO nano‐sheets. FT‐IR spectra of GO/Ag2O composite illustrate the reduction in intensity of peaks as compared to pure Ag2O. Some oxygen functional groups are also reduced in the composites samples. The antibacterial activity of hetero systems was observed in case of E.coli and Staph aureus by disc diffusion method. In antibacterial activity, pure Ag2O and GO exhibited small zones of inhibition in comparison to 2.0 and 4.0% GO/Ag2O nano composite materials towards E. coli and S. aureus. The results indicated that GO/Ag2O nanocomposites can markedly inhibit E. coli reproduction as compared to S. aureus. In antibacterial mechanism, positively charged Ag ions and reactive oxygen species (ROS) are produced more in GO/Ag2O nanocomposites than singly Ag2O and GO nanomaterials which cause the disrupting interaction with bacterial cell wall through membrane proteins. The effectiveness of Ag2O NPs is enhanced by incorporating GO nano‐sheets.

Antimicrobial Susceptibility and Virulence Surveillance of Campylobacter spp. Isolated From Patients in Two Tertiary Medical Centers in Taiwan.

Campylobacter spp. may cause fever, vomiting, and diarrhea in humans. Antibiotic treatment is suggested for patients with severe campylobacteriosis. However, the interpretative criteria for antibiotic susceptibility are inconsistent between Clinical and Laboratory Standards Institute and European Committee on Antimicrobial Susceptibility Testing guidelines. The aim of the study is to investigate the antibiotic susceptibility and prevalence of cytolethal distending toxin genes and to evaluate antibiotic susceptibility testing methods in the clinical laboratories of two tertiary medical centers in Taiwan. In total, 236 bacterial isolates were collected between 2001 and 2014. The disk diffusion and E-test methods were used to evaluate the antibiotic susceptibility, and broth dilution results were used as a reference. The virulence genes cdtA, cdtB, cdtC, and ceuE were detected through polymerase chain reaction. The antimicrobial sensitivity rates for erythromycin, ciprofloxacin, and tetracycline using the broth dilution assay were 80.4, 5.4, and 3.4%, respectively. No significant differences were observed in the antibiotic susceptibility of the isolates obtained from southern and northern Taiwan. However, some differences were observed between species. The susceptibility test for erythromycin (disk diffusion) showed that the isolates with small inhibition zone diameters were all resistant, and five isolates (4.0%) with large IZDs were non-sensitive. The error rate of the disk diffusion method according to the CLSI M45-A3 guideline was 5.4% (8/148). The incompatibility rates between the E-test and broth dilution methods for erythromycin, ciprofloxacin, and tetracycline were 8.0, 5.3, and 1.3%, respectively. The positive rates of the genes cdtA and cdtC were considerably higher in Campylobacter jejuni than in C. coli. Erythromycin is recommended as the first choice of treatment for campylobacteriosis. The disk diffusion method is suitable for prescreening Campylobacter susceptibility by using the CLSI M45-A2 and EUCAST criteria (low error rate of 3.4%). If antibiotic treatment fails or IZDs are between 6 and 20 mm, minimum inhibitory concentration testing by using the E-test method is highly recommended because the results of the E-test and broth dilution methods exhibit high agreement. The error rate of disk diffusion method using CLSI M45-A3 criteria is only slightly higher than B, which is also a suitable criteria.

Antimicrobial Effect of Different Sizes of Nano Zinc Oxide on Oral Microorganisms.

Objectives:The purpose of the present study was to evaluate the antimicrobial effect of various sizes and concentrations of zinc oxide (ZnO) nanoparticles on Streptococcus mutans (S. mutans), Enterococcus faecalis (E. faecalis), Lactobacillus fermentum (L. fermentum), and Candida albicans (C. albicans).Materials and Methods:Solutions at the concentration of 10 μg/ml were prepared using 20-nm, 40-nm, and 140-nm nano ZnO (nZnO) powder. The antimicrobial effect of nZnO was determined using the disk diffusion method. The inhibition zone (mm) was measured using a ruler. Data were analyzed by analysis of variance (ANOVA) and the Bonferroni correction. The minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of nZnO were determined using the broth microdilution method in Mueller-Hinton Agar (MHA) for S. mutans and E. faecalis, De Man, Rogosa, and Sharpe (MRS) agar, and Sabouraud Dextrose Agar (SDA).Results:The greatest inhibition zones were observed against S. mutans with 20-nm and 40-nm nZnO, while 140-nm nZnO formed the greatest inhibition zones against S. mutans and E. faecalis. The smallest inhibition zones were observed against C. albicans with the three nZnO particle sizes. The MICs for C. albicans with 40-nm and 140-nm particles and for L. fermentum with 140-nm particles were higher than 10 μg/ml. A significant correlation was found between the particle size and the antibacterial activity against S. mutans (P=0.00), L. fermentum, and E. faecalis (P<0.02).Conclusion:The antimicrobial activity of nZnO increases with decreasing the particle size. The greatest antimicrobial effect was observed against S. mutans and E. faecalis. S. mutans is more sensitive to the changes in the particle size compared to other bacteria.

In vitro evaluation of Syzygium aromaticum L. ethanol extract as biocontrol agent against postharvest tomato and potato diseases

E thanolic extract of dried flower bud of Syzygium aromaticum L. (clove) was investigated to evaluate its antifungal activity against local fungal isolates causing postharvest infections form potato and tomato. Four fungal isolates; Geotrichum candidum, Alternaria alternata, Fusarium oxysporum and Mucor hiemalis were identified. All fungal isolates were found to be inhibited by the extract; whereas the smallest inhibition zone) of S. aromaticum extract was 2.5% for M. hiemalis, A. alternata, G. candidum and 12.5% for F. oxysporum. Quantitative assessment of phytochemical compounds in clove plant revealed the presence of phenolic acids (20.80%); flavonoids (26.81%); tannins (4.90%), saponins (2.60%), alkaloids (1.60%), total protein (17.83%), total carbohydrate (2.23%) and total oil (0.90%). Biochemical profile was revealed by GC/MS which detect 18 different chemical compounds. The major compounds were eugenol (17.27%), trans-caryophyllene (0.50%), humulene (3.33%), anthracenedione (3.35%), cedran-diol (0.61%), citroflex A (5.45%) and lucenin 2 (8.25%). TLC technique and different solvent systems were employed to select the proper one based on its capacity to isolate the maximum number of fluorescent spots in crude extract.Chloroform-acetone-butanol (CAB) 85:15:20 could efficiently separate three bands (A, B and C). Each detected band was individually screened for its antifungal activity against the isolated fungi. Only band C showed a significant antifungal activity. Mass spectroscopy (MS) was used to investigate characteristics, purity as well as expectation of both chemical formula and molecular weight of the isolated compounds; which finally proved that glucoside β-sitosterol was the main compound represented in fraction -C.

Hoạt tính kháng khuẩn của một số cao chiết thảo dược kháng vi khuẩn gây bệnh ở tôm nuôi

This study was carried out to determine the antimicrobial activity of seven herbal extracts (Ricinus communis L., Hedyotis corymbosa L., Vernonia amygdalina del., Moringa oleifera, Callisia fragrans, Acanthus ilicifolius L. and Wedelia calendulacea (L) Less) which were collected in the Mekong Delta. Antimicrobial activity, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) of the seven herbal extracts were screened for two common shrimp pathogens (Vibrio harveyi and Vibrio parahaemolyticus). The results showed that (i) seven herbal extracts have different antimicrobial activity; the extract of R. communis showed the highest diameter of the inhibition zone from 17 -18 mm, followed by the extracts of V. amygdalina del., M. oleifera, A. ilicifolius L. and W. calendulacea (L) Less. with the inhibition zone range of 10 - 11 mm. Similarly, the smallest inhibition zone was recorded for the extracts of H. corymbosa L. and C. fragrans) at 7 and 8 mm, respectively; (ii) The results suggested that were also found to be effective at the extract of R. communis L for against V. harveyi, V. parahaemolyticus, with MIC and MBC values were 1.25 mg ml-1 and 2.5 mg ml-1; 2.5 mg ml-1 và 5.0 mg ml-1, respectively.

Copper sulfate-embedded and copper oxide-embedded filter paper and their antimicrobial properties

In this study, copper sulfate was successfully embedded in filter paper through soaking and copper oxide was successfully embedded in filter paper via in situ technique using the copper sulfate-embedded paper as the starting material. Using color analysis, the filter paper soaked with copper sulfate solution was observed to change color from white to blue, indicating the presence of embedded copper sulfate salts. Furthermore, upon soaking this filter paper with sodium hydroxide solution, the color changed from blue to brown, indicating the presence of copper oxide. X-ray diffraction (XRD) spectroscopy confirms the observed results of the color analysis. Scanning electron microscopy (SEM) and electron dispersive x-ray (EDX) spectroscopy were used to determine the surface morphology and elemental composition of the samples, respectively. The antimicrobial property of the filter paper with copper-based particles was tested against Gram-negative bacterium (Escherichia coli) and Gram-positive bacterium (Staphylococcus aureus), and two species of fungi (Candida albicans and Aspergillus niger) using disc diffusion method. The reactivity of the copper sulfate-embedded filter paper against E. coli was found to be severe, whereas that against S. aureus was moderate. The reactivity of the samples against the two fungi was mild, having a relatively small zone of inhibition. For the copper oxide-embedded paper, the reactivity of the paper to both bacteria was moderate, whereas it shows no reactivity to C. albicans and only a mild reactivity to A. niger. After 60 min of contact with Escherichia coli, both the copper sulfate-embedded and copper oxide-embedded filter papers reduced the amount of colony forming unit to more than 99.9%.

Embedding of copper sulfate and copper oxide on multipurpose paper

Copper sulfate salts were embedded on multipurpose paper using simple soaking technique while copper oxide particles were embedded using in-situ technique. In simple soaking technique, the papers were simply soaked in copper sulfate solution in order for the copper salts to be incorporated in the paper. In the in-situ technique, the copper sulfate-embedded papers were soaked in sodium hydroxide solution for reactions to occur that will lead to the formation of copper oxide. Copper sulfate-embedded papers have blue green color while copper oxide-embedded papers have brown color. The copper sulfate-embedded paper shows excellent antimicrobial property against Staphylococcus aureus. Meanwhile, the copper oxide-embedded paper shows small zone of inhibition against Escherichia coli and Staphylococcus aureus.

The in vitro activity of selected mouthrinses on standard strains of fungi

An oral cavity hygiene plays a key role in prophylactic and therapeutic measures to prevent pathological changes caused by different viruses, bacteria, fungi and protozoa. It is important to maintain proper oral hygiene and assist the removal of potent pathogens; use of the mouthrinses can be one of method providing to these goal. The purpose of this study was to investigate the effects of selected mouthrinses on the standard strains of Candida presented in the oral cavity. Eight reference strains of fungi were investigated: C. albicans (CBS 2312), C. albicans (L 45), C. albicans (ATCC 24433), C. dubliniensis (CBS 7987), C. glabrata (CBS 862), C. krusei (CBS 573), C. parapsilosis (CBS 10947) and C. tropicalis (CBS 2424). Thirteen mouthrinses were used in the study, including pure chlorhexidine (CHX), and 12 commercially available varieties: Azulan, Colgate Plax Complete Care Sensitive, Corsodyl 0,2%, Curasept ADS 205, Dentosept, Dentosept A, Eludril Classic, Listerine Total care, Octenidol, Oral-B Pro-Expert Clinic Line, Sylveco and Tinctura salviae. The present study used a qualitative diffusion in agar gel-well plate method to evaluated the antifungal properties of mouthrinses. Among the 12 commercially available mouthrinses examined in the study, the following were not found to show antifungal activity: Azulan, Dentosept, Eludril Classic, Listerine Total care, Tinctura salviae. The largest inhibition zones were produced by Dentosept, Chlorhexidine and Colgate. The smallest inhibition zones were produced by Octenidol and Curasept. With regard to mouthwash type, statistically significant differences in growth inhibition zone diameter were found between the following pairs of fungi: C. albicans and C. krusei for Colgate without dilution and with 1:2 dilution; C. albicans and C. glabrata for Corsodryl without dilution and with 1:2 dilution; C. albicans and C. dubliniensis for Dentosept A without dilution; C. glabrata and C. parapsilosis with 1:2 dilution; C. dubliniensis and C. tropicalis for Sylveco without dilution, 1:2 dilution and 1:4 dilution; C. dubliniensis and C. parapsilosis for Sylveco without dilution, 1:2 dilution and 1:4 dilution. The lowest MIC values calculated from the Iinear regression equation, indicating the strongest potential activity, were obtained for Dentosept A, followed by chlorhexidine; the lowest activity, was calculated for Curasept and for Octenidol. Some of the tested mouthrinses have antimycotic properties at commercially available concentrations. In spite of the fact that chlorhexidine is thought to be the gold standard for mouthrinse use, Dentosept has stronger antimycotic activity and acts on a wider spectrum of fungi species. Chlorhexidine and Colgate do not appear to act against C. tropicalis, neither does Curaspet against C.dubliniensis; therefore, the determination of the fungus species is necessary.

Investigation the Antibacterial Activity of Portulaca oleracea L. Tissue Cultures in vitro

The objective of this research was to studying the antibacterial activity of Portulaca oleracea L. in vitro cultures. P. oleracea leaves were collected from the local markets. Callus tissues were induced from the plant leaves (expalnt) through inoculating the explants on MS medium supplemented with different concentrations of 2, 4-D (0.0, 2.0 or 3.0 mg/l) and Kintin (0.0 or 0.5 mg/l). All cultures were incubated at 25 ± 2°C in dark. Water and ethanol extracts of P. oleracea were prepared. Bacterial samples were collected, they consist of gram-positive bacteria (Staphylococcus aureus) and gram-negative bacteria (Pseudomonas aeruginosa). Antibacterail activity of P. oleracea extracts were investigated using diffusion method. Results shown that mean % callus induction, callus fresh weight and callus dry weight inceasred significantly in 2.0 mg/l 2, 4-D or 3.0 mg/l 2, 4-D with 0.5 mg/l kin in comparsion to the control (0.0), and the highest mean obtained at 3.0 mg/l 2, 4-D with 0.5 mg/l kin recording 80% and 94 mg and 52 mg for % callus induction, callus fresh weight and callus dry weight respectively. Also there was no significat differences ocurred in the mean inhibition zone diameter (mm) of the bacterial isolates treated with water or ethanol extracts of callus tissues recording 10 and 9.5 mm respectively compard with control (14.5 mm) and mean inhibition zone (mm) significantly decreased in other treatment types in compasion to the control. The results obtained in this research work clearly indicated a promising potential of P. oleracea extracts as antibacterial agent and inspite of the small inhibition zone diameter obtaind using plant extract but it has proved highly efficiency as an anti bacterial compared with the higher concentration of the standard antibiotic used in this experiment.

The antimicrobial and antioxidant activity of Muscari neglectum flower ethanol extract

Summary Introduction: Muscari neglectum has been used as food in some countries. Objective: The antimicrobial and antioxidant activities of M. neglectum were the subject of the study. Methods: In this study, the total phenolic, flavonoid, monomeric anthocyanin contents, antioxidant and antimicrobial activity of M. neglectum flowers ethanol extract were determined by different methods against some food poisoning microorganisms. Results: Total phenolic, flavonoids and anthocyanin contents of the extract were 18.2, 0.94 and 0.11%, respectively. The IC50 for M. neglectum was higher than that of BHT. M. neglectum extract showed no inhibition zone (IZ) against Staphylococcus aureus and had small IZ against Candida albicans and Aspergillus niger. Shigella flexneri and Escherichia coli had the higher IZ than the others. The lower MIC and MLC values were for C. albicans, followed by Sh. flexneri and E. coli. S. aureus had the higher MIC and MLC values than the others. Conclusion: Therefore, the M. neglectum flower extract can be used as a natural preservative and coloring agent in foods as replacement of synthetic ones.

An in vitro investigation into the efficacies of chlorhexidine gluconate, povidone iodine and green tea (Camellia sinensis) to prevent surgical site infection in animals

Background: Surgical site infections are common in veterinary practice; their prevention is based on the preoperative use of topical antimicrobials at the surgical site to reduce resident bacteria to sub-pathogenic levels. Aim Chlorhexidine gluconate (CHG) and povidone iodine (PI) are the most popular options for preoperative skin preparation in veterinary practice, however increasing bacterial resistance to CHG and PI have been reported; therefore investigation into alternative antimicrobials such as Camellia sinensis (green tea: GT) is required. Method The Kirby-Bauer disk diffusion method was used to test the antibacterial activity of four dilutions of CHG, PI and GT on the normal flora of animal skin, represented by S. aureus, S. intermedius, S. uberis and S. pyogenes. Zones of inhibition (ZOI) were measured to assess antimicrobial action. Kruskal-Wallis analyses with Mann-Whitney post-hoc tests determined differences in efficacy between the dilutions of antimicrobials for each bacterium tested. Results All antimicrobials inhibited bacterial growth, CHG was more efficacious than PI and GT (p&lt;0.0001; mean CHG: 24.02± 2.05 mm; mean PI: 4.46±1.35 mm; mean GT: 2.90mm±2.60mm). Although GT produced smaller ZOIs than PI, no significant differences in efficacy existed (p&gt;0.05). Conclusion The results suggest that CHG is the best antimicrobial for preoperative skin preparation. GT did produce an antibacterial effect on three of the four bacteria, although this was inferior to the existing veterinary products used. Therefore GT in the formulation tested is not recommended for use as a veterinary antimicrobial.

Screening of Herbal-Based Bioactive Extract Against Carbapenem-Resistant Strain of Acinetobacter baumannii.

Acinetobacter baumannii is grouped in the ESKAPE pathogens by Infectious Disease Society of America, which is linked to high degree of morbidity, mortality, and increased costs. The high level of acquired and intrinsic resistance mechanisms of these bacteria makes it an urgent requirement to find a suitable alternative to carbapenem, a commonly prescribed drug for Acinetobacter infection. In this study, methanolic extracts of six medicinal plants were subjected to phytochemical screening and their antimicrobial activity was tested against two strains of A. baumannii (ATCC 19606, carbapenem-sensitive strain, and RS 307, carbapenem-resistant strain). Synergistic effect of the plant extracts and antibiotics was also tested. Bael or Aegle marmelos contains tannin, phenol, terpenoids, glycoside, alkaloids, coumarine, steroid, and quinones. Flowers of madar or Calotropis procera possess tannin, phenol, terpenoids, glycoside, quinone, anthraquinone, anthocyanin, coumarin, and steroid. An inhibitory growth curve was seen for both the bacterial strains when treated with A. marmelos, Curcuma longa, and leaves and flowers of C. procera. Antibiotics alone showed a small zone of inhibition, but when used with herbal extracts they exhibited larger zone of inhibition. Synergistic effect of A. marmelos and imipenem was the best against both the strains of A. baumannii. From this study, it can be concluded that extracts from A. marmelos and leaves and flowers of C. procera exhibited the most effective antibacterial activity. These herbal extracts may be used to screen the bioactive compound against the carbapenem-resistant strain of A. baumannii.