Significant Differences In Antibacterial Activity Research Articles

In vitro antibacterial activity of Morinda citrifolia extracts against eight pathogenic bacteria species.

Medical professionals continue to face a severe issue with the evolution of resistance to conventional antibiotics. The search for new novel compounds from plants has been proven to be the alternative solution. Morinda citrifolia is used traditionally for the treatment of infectious diseases. The present study investigates the antibacterial properties of M. citrifolia root, leaf, and fruit (fresh, dried, and fermented) extracts on three-gram-positive and five-gram-negative bacteria. The plant parts were processed and extracted in distilled water and ethanol (60%, 80%, and absolute (100%)). The antibacterial activities of the extracts were assessed in vitro using the agar well diffusion method, with Ciprofloxacin serving as the positive control. All the tests were conducted three times to obtain the average value of inhibition zones. Overall, root extracts showed the most significant antibacterial activity, followed by dried fruit, fermented fruit extract, fresh fruit, and the least leaf extract. Using one-way ANOVA and Tukey's post-hoc tests, the statistical analysis revealed significant differences in antibacterial activity among the extracts and solvent concentrations. The 100% ethanol extracts had significantly higher zones of inhibition compared to the other solvents. The most inhibitory activity was against Campylobacter spp. (21.33±1.80) for the 80% ethanol root extract. All the extracts of M. citrifolia were found to exhibit moderate antibacterial activity against all the bacteria pathogens. However, Enterococcus faecium, Campylobacter spp., and Bacillus cereus were most sensitive to all the plant extracts while Shigella spp. and Klebsiella spp. showed resistance to most extracts. This observed difference is significant for each strain extract depending on the bacteria strain and the type of solvent extract (p < 0.001). The findings indicate a promising antimicrobial potential of M. citrifolia extracts.

Potential of Erythrosine-Mediated Photodynamic Therapy as a Cavity Disinfectant: Antibacterial Efficacy and Bonding Ability

This study aimed to evaluate the antibacterial efficacy of erythrosine-mediated photodynamic therapy (PDT) against &lt;i&gt;Streptococcus mutans&lt;/i&gt; (&lt;i&gt;S. mutans&lt;/i&gt;) in dentin and its effect on the shear bond strength (SBS) of composite resin to dentin. Eighty extracted human noncarious premolars were used in this study. Forty teeth were used for the antibacterial activity test, while the remaining 40 were used for the SBS test. Both experiments were conducted with 4 experimental groups (n = 10): control (distilled water), sodium hypochlorite (NaOCl, 6%), chlorhexidine (CHX, 0.12%), and erythrosine-mediated PDT. Antibacterial effects were evaluated by counting &lt;i&gt;S. mutans&lt;/i&gt; colony-forming units (CFUs). The SBS of composite resins to dentin was measured using a universal testing machine. All treatments (NaOCl, CHX, and PDT) demonstrated statistically significant differences in antibacterial activity compared with the control group (&lt;i&gt;p&lt;/i&gt; &lt; 0.05). The antibacterial effects were ranked from strongest to weakest as follows: NaOCl, PDT, and CHX. In the SBS test, the NaOCl group exhibited a statistically significant difference compared with the CHX, PDT, and control groups (&lt;i&gt;p&lt;/i&gt; &lt; 0.05), with the lowest bond strength. No statistically significant differences were found among the CHX, PDT, and control groups (&lt;i&gt;p&lt;/i&gt; &gt; 0.05). Erythrosine-mediated PDT exhibited significant antibacterial effects against &lt;i&gt;S. mutans&lt;/i&gt;, with higher antibacterial activity than CHX but lower than NaOCl. Only NaOCl negatively affected the bond strength of composite resin to dentin. In conclusion, erythrosine-mediated PDT shows potential as a cavity disinfectant due to its significant antibacterial effects against &lt;i&gt;S. mutans&lt;/i&gt; and lack of adverse effects on bond strength.

Phytochemical Screening &amp; Antibacterial Activity of Clitoria ternatea L Extract against Staphylococcus epidermidis Bacteria

Telang flowers contain secondary metabolite compounds that have benefits as antibacterial or antiseptic compounds including flavonoids, tannins, alkaloids and saponins. This research was an experimental research. Telang flower extract was obtained using 70% ethanol solvent by remaceration method then it tested like phytochemical content. Antibacterial activity testing with variaty concentrations media MHA (Mueller Hinton Agar) 15, 30, 45, 60, and 75% against Staphylococcus epidermidis. The positive control was Klindamycin. The obtained data were analyzed by Statistical Package for the Social Sciences (SPSS). The results shown that telang flower extract with concentrations 15, 30, 45, 60 and 75% had an average inhibition zone activity against Staphylococcus epidermidis were respectively 4.45 (15%); 4.63 (30%); 4.35 (45%); 5.47 (65%); and 7.02 mm (75%). The SPSS results show that the p value is &lt;0.05 at the 95% confidence level, which indicates that there is a significant difference in antibacterial activity between butterfly pea flower extracts between concentrations of 15, 30, 45, 60, and 75%. Post hoc tests using LSD showed that there was a difference in antibacterial activity between concentrations of 75% and concentrations of 15, 30, 45, and 60%, but there was no difference in antibacterial activity between concentrations of 15, 30, 45, and 60%.Minimal inhibitor concentration of telang flower extract was obtained at 15%

Effect of pH, Carbon and Nitrogen Sources on Antibiotic Production by Actinomycetes Isolates from River Tana and Lake Elementaita, Kenya

The escalating concern over antibiotic resistance and its profound impact on public health have underscored the urgent need to explore alternative reservoirs of antimicrobial agents. In this regard, Actinomycetes have emerged as a compelling area of investigation due to their remarkable capacity to produce bioactive compounds. Therefore, this study sought to investigate the influence of pH and various carbon and nitrogen sources on the antibacterial activity of Actinomycetes isolates collected from Lake Elementaita and River Tana. By examining the effects of these factors, we aimed to gain insights into the optimization of growth conditions and nutrient availability to enhance the production of bioactive compounds with potent antibacterial properties. The Actinomycetes isolates used in this study were from Lake Elementaita and River Tana, known for their diverse ecological characteristics and potential as sources of bioactive compounds. The isolates were subjected to morphological, biochemical, and molecular techniques to ensure accurate identification. To assess the antibacterial activity of the Actinomycetes isolates, they were tested against E. coli using the agar well diffusion method. The independent variables examined in this study were pH levels (4, 7, and 9) as well as different carbon sources (fructose and sucrose) and nitrogen sources (urea and sodium nitrate). The diameter of the inhibition zones served as the dependent variable. The data collected on the effects of pH and nutrients on the inhibition zones of Actinomycetes isolates were subjected to statistical analysis. One-way ANOVA was performed to assess significant differences in antibacterial activity among the isolates under different carbon and nitrogen preference. Mean values were compared using the LSD test at a significance level (α) of 0.05. Furthermore, the Kruskal-Wallis test was utilized to analyze the pH preferences of the Actinomycetes isolates at a significance level (α) of 0.05. The results showed that pH significantly influenced the bioactivity of the Actinomycetes isolates, with pH 7 exhibiting the highest inhibition zones against E. coli. The isolates displayed varied antibacterial activities depending on the carbon and nitrogen sources provided. Sucrose was the most preferred carbon source, followed by fructose, while urea was the preferred nitrogen source, followed by sodium nitrate. The study concluded that pH and nutrient availability play crucial roles in determining the antibacterial activity of Actinomycetes isolates. Other than contributing to our in-depth understanding of the factors influencing the antimicrobial potential of Actinomycetes, the results of this study highlight the importance of optimizing growth conditions and nutrient availability to enhance the production of bioactive compounds with potent antibacterial properties. Further investigations and exploration of Actinomycetes from diverse environments are recommended to discover new bioactive molecules for combating antibiotic resistance.

Evaluation of Chemical Compounds and Comparison of Antibacterial Activity of Essential Oil and Nanoemulsion Containing Essential Oil of Ziziphora clinopodioides L

Introduction: Medicinal plants have played a major role in the treatment of multiple diseases for centuries. Ziziphora clinopodioides is one of these plants with well-known antibacterial properties. The present study aimed to investigate the antibacterial effects of Z. Clinopodioides essential oil and nanoemulsion. Method: After preparing and collecting the plant in spring, the samples were dried in the shade and transferred to the laboratory. Thereafter, the essential oil was extracted by Clevenger. Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus were used to determine antibacterial properties. Results: Pulegone had the highest composition (44.49%) of essential oil. Particle size in 5% nanoemulsion of Z. Clinopodioides essential oil was 13.0 nm. The results demonstrated that considering the diameter zone of the no-growth, there was no significant difference between 5% nanoemulsion and 5% Z. Clinopodioides essential oil in both gram-positive and gram-negative bacteria. Conclusion: Nanoemulsion containing essential oil showed no significant difference in antibacterial activity compared to essential oil

UJI AKTIVITAS ANTIBAKTERI MASKER GEL PEEL OFF EKSTRAK DAUN PLETEKAN (Ruellia tuberosa L.) TERHADAP Staphylococcus aureus

Staphylococcus aureus is one of the pathogenic bacterial species. Pletekan plant has potential as a medicinal plant. This plant contains secondary metabolites and has been shown to have an antibacterial effect. The purpose of this study was to determine whether the peel off gel mask pletekan leaf extract could inhibit the growth of Staphylococcus aureus and whether there was a difference in the antibacterial activity of the peel off gel mask pletekan leaf extract at concentrations of 20%, 25%, and 30%. This research used maceration extraction method, phytochemical filtering and TLC. Peel off gel mask formulation from extracts with different concentrations. Furthermore, the research was carried out to test the antibacterial activity by using the well-drilled method on the peel off gel mask of pletekan leaf extract (Ruellia tuberosa L.) against the growth of Staphylococcus aureus. The results of screening and TLC showed pletekan leaf extract containing flavonoids, steroids, triterpenoids, and alkaloids. The peel off gel mask preparation test includes organoleptic, pH, homogeneity, adhesion, dispersion and drying time included in the Indonesian National Standard Criteria. The results showed that pletekan leaf extract (Ruellia tuberosa L.) in a peel off gel mask could inhibit the growth of Staphylococcus aureus. The results of statistical tests showed that the data were normally distributed and homogeneous. There was a significant difference in antibacterial activity in the peel off gel mask of pletekan leaf extract with concentrations of 20%, 25% and 30%, which were 4.323mm; 5.218mm; and 6.509mm. The antibacterial activity showed that the concentration was directly proportional to the resulting inhibition zone.

IDENTIFICATION OF CHEMICAL COMPOUNDS AND ANTIBACTERIAL ACTIVITY TEST OF Kirinyuh LEAF EXTRACT (Chromolaena odorata L.) FROM Ie Seum GEOTHERMAL AREA, REGENCY OF ACEH BESAR, INDONESIA

This research aims to identify and compare the chemical components of Chromolaena odorata leaf extract grown in the geothermal and outer areas of the geothermal source site. The antibacterial activity of the plant extracts was also identified. The plant materials were collected from the Ie Seum Geothermal area and Blangkrueng region, approximately 31 km from the geothermal area. All samples were extracted using three different solvents: ethanol, nhexane, and ethyl acetate. A phytochemical test was performed to identify the secondary metabolites, volatile components were identified using GC-MS, and the inhibition zone method was used to assess the antibacterial activity of the extracts against S. aureus. The ethanol extract and ethyl acetate from both areas contained phenolic, flavonoid, and steroid, while the n-hexane extracts from both areas’ steroid groups were identified. In addition, GCMS data revealed that the plant material sample from the geothermal contained more chemical constituents compared to the sample from the geothermal outer area. The extract from geothermal also shows better antibacterial activity against S. aureus, and statistical analysis indicates a significant difference in antibacterial activity among solvents and between the origin of the samples.

Formulation and Characterization of Essential Oils Based Antibacterial Hand Sanitizer Gels

Purpose: The usage of herbal-based antibacterial sanitizers is increasing, and they have considerably shown fewer side-effects than sanitizers with synthetic compounds. In the present study, essential oils obtained from cinnamon and lime were used to formulate hand sanitizer gels, and their efficacy was evaluated. Method: Three different hand sanitizer gel formulations were prepared using cinnamon oil (Formulation A), lime oil (Formulation B) and a mixture of cinnamon and lime oil (Formulation C). Carbopol 940 was used as the gelling agent. Tests for organoleptic, physicochemical characteristics and stability were conducted on the prepared formulations. The antibacterial activity of the prepared formulations was evaluated using the agar diffusion method. All three formulations were compared with a commercial liquid hand wash product for their in vitro antibacterial activity. Three-way ANOVA with Tukey's honestly significant difference test was used to compare the antibacterial activity of the hand sanitizer gel formulations. Stability of the three hand sanitizer formulations were assessed. Results: Considerable differences in the pH and viscosity were not observed between the prepared hand sanitizer gel formulations. However, considerable changes in the spreadability were observed between the prepared hand sanitizer gel formulations. A statistically significant difference in antibacterial activity was observed among the three hand sanitizer gels and the commercial hand wash (p&lt;0.05). Formulation C showed the highest antibacterial activity among the prepared hand sanitizer formulations. Based on the stability studies, Formulation A was found to be the most stable. Conclusion: Hand sanitizer gel containing a mixture of cinnamon and lime oils showed the highest antibacterial activity among prepared formulations. However, the most stable formulation was the hand sanitizer gel containing cinnamon oil.

Evaluation of Antibacterial Activity of Cymbopogon Nardus L. on The Growth of Enterococcus Faecalis

Background: Cymbopogon nardus L. known as citronella grass is traditional medicinal plant that contains saponins, polyphenols, alkaloids, flavonoids, and essential oil. Based on the previous study, it is known that it has antibacterial properties. Objective: The aim of this study was to determine antibacterial activity of Cymbopogon nardus L. in inhibiting the growth of Enterococcus faecalis. Methods: The samples were Cymbopogon nardus L. extracts with concentration of 1%, 3%, 5%,7%, 9%, and 5% NaOCl as positive control. Antibacterial activity of citronella extract against E. faecalis was observed with the formation of inhibitory zone diameter in agar. Data were analyzed using SPSS with one-way ANOVA and LSD test. Result: The result showed that Cymbopogon nardus L. was able to inhibit the growth of E. faecalis at concentration 1%,3%,5%,7% and 9%. There was a significant difference in antibacterial activity among all groups. It showed that concentration of 9% showed the highest zone of inhibition, but it was not as effective as NaOCl 5%. NaOCl showed the highest zone of inhibition. Conclusion: Cymbopogon nardus L. had antibacterial activity in inhibiting the growth of E. faecalis. The higher the concentration of citronella extract, the higher the antibacterial activity possessed.

Comparative evaluation of antibacterial activity of solvent fractions and essential oil of Cyperus rotundus L. rhizomes

Cyperus rotundus L. belongs to the family Cyperaceae. It is used to treat constipation, stomach disorders, dysmenorrhea, skin diseases, wounds, leprosy, fever, etc., in indigenous medicine. Also, they are used to treat itchy pus-filled pimples in Sri Lanka. This study aimed to evaluate in vitro antibacterial activity of different solvent fractions and essential oil of Cyperus rotundus L. rhizomes. Soxhlet apparatus was used to obtain the methanolic and petroleum ether extracts from rhizomes, and essential oil was extracted using steam distillation. The antibacterial activity of extracts and essential oils was determined against Staphylococcus aureus and Pseudomonas aeruginosa using the agar disc diffusion method. The activity was compared with Gentamycin as standard. The activity of extracts and essential oil were compared with one-way ANOVA followed by Dunnett's test. The results showed that both extracts and essential oil of Cyperus rotundus L. rhizomes showed a statistically significant difference in antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa compare to the standard drug, Gentamycin. The essential oil of Cyperus rotundus L. rhizomes showed comparatively higher antibacterial activity than extracts. Staphylococcus aureus was more susceptible to methanolic extract and essential oil than petroleum ether extract. Pseudomonas aeruginosa was more susceptible to essential oil and petroleum ether extract than methanol extract. Cyperus rotundus L. rhizomes possess good antibacterial activity, and further studies are required to isolate active phytochemicals and screen for antimicrobial activity.

Comparative study of antimicrobial activity between some medicine plants and recombinant Lactoferrin peptide against some pathogens of cultivated button mushroom.

The adverse effects of chemical pesticides on human health and environment cannot be ignored, hence it seems that novel alternative compounds should be applied to control plant pathogens. Among various alternative sources, natural compounds such as plant essential oils, plant extracts and recombinant antimicrobial peptides are of significance. The aim of the present study was to investigate antimicrobial activity of plants essential oils and plant extracts of six medicinal plants (Lippia citriodora, Ferula gummosa, Bunium persicum, Mentha piperita, Plantago major and Salvadora persica) along with a chimera peptide of camel lactoferrin, which is the most important antimicrobial component of camel milk, against Pseudomonas tolaasii and Trichoderma harzianum as pathogens of white button mushroom. The antibacterial activity test was conducted under in vitro conditions through disc diffusion method. The results showed that chimera camel lactoferrin peptide, with the highest amount of inhibitory zone (14.63mm in 20μg/mL concentration), has a significant difference in antibacterial activity compared to other treatments. Ferula gummosa conferred no antibacterial activity. Also, the results of antifungal effects indicated that plant essential oils and extracts have more antifungal activity than recombinant peptide. Generally, L. citriodora, B. persicum, M. piperita treatments could completely prevent growth of fungal in in vitro conditions. Therefore, using the mentioned plants can be a good replacement for reducing the chemical pesticides against pathogenic agents of button mushroom, without any adverse effects on environment and human health.

Antibacterial activity of silver and titania nanoparticles on glass surfaces

A liquid flame spray (LFS) nanoparticle deposition process was used to generate glass surfaces with silver (Ag) and titania (TiO2) nanoparticles for antibacterial activity against two common pathogenic bacteria causing community-associated and hospital-acquired infections, gram positive Staphylococcus aureus (S aureus) and gram negative Escherichia coli (E coli). All nanoparticle coatings increased antibacterial activity compared to a reference glass surface. The Ag nanoparticle coatings showed the highest antibacterial activity with E coli. On the contrary, TiO2 nanoparticle coatings were found to have a higher antibacterial activity against S aureus than E coli. No significant differences in antibacterial activity were observed between the two used nanoparticle deposition amounts.

Green synthesis of silver nanoparticles using Thymbra spicata L. var. spicata (zahter) aqueous leaf extract and evaluation of their morphology-dependent antibacterial and cytotoxic activity

Silver (Ag) nanoparticles (NPs) were green synthesized at room temperature using different concentrations of the Thymbra spicata L. var. spicata (Zahter) aqueous leaf extracts for the first time. With the synthesis of AgNPs using the leaf extract of Cynara scolymus (Artichoke) and Mentha piperita (Peppermint), the biological activities of the nanoparticles synthesized using leaf extract of three economically significant plants have been studied comparatively. Nanoparticles were characterized by different spectroscopic and microscopic analysis. TEM analysis of the biosynthesized AgNPs revealed that the size and shape of the AgNPs were changed with the plant extract concentration. Biologically synthesized AgNPs from leaf extracts of the three different plants displayed significant differences in antibacterial activity against two different gram-negative and gram-positive bacteria. Also, the results from this study show the shape dependence of the antibacterial and cytotoxic activity of silver nanoparticles synthesized using T. spicata leaf extract. The nanoparticles with different shapes exhibited the strongest antibacterial and cytotoxic activity compared to mostly spherical nanoparticles. Present results clearly indicate that biological activities of silver nanoparticles were affected by nanoparticle shape and the source of the plant extract used in the synthesis.

Antimicrobial activity of aqueous and methanol extract of naturally growing and cultivated Aloe turkanensis

The aim of the study was to determine the antibacterial properties of aqueous and methanol extracts of naturally occurring and cultivated Aloe turkanensis. The plant is widely used as a traditional herb by communities in Turkana County, Kenya. However its efficacy has not been established. Aqueous and methanol extract of a naturally occurring whole Aloe turkanensis and cultivated one was obtained. The extracts were tested for in-vitro activity against 4 standard bacterial cultures and a fungal clinical isolate. Benzyl penicillin, Gentamycin and Amphotericin B were used as positive controls. Efficacy data analysis showed that methanol extracts of naturally growing plant inhibited the growth of B. cereus (100 mg/ml), S. aureus (100 mg/ml), and P. aeroginosa (200 mg/ml) with mean diameters of inhibition zones for S. aureus and B. cereus being 18.5±0.7 mm and 16.5±0.7 mm, respectively. Aqueous extract of the plant inhibited the growth of B. cereus and S. aureus at a Minimum Inhibitory Concentration of 200 mg/ml and 50 mg/ml respectively with mean diameter of inhibition zones for S. aureus and B. cereus being 19.75±1.0 mm and 11.5±0.0 mm respectively. Methanol extracts of cultivated A. turkanensis inhibited the growth B. cereus (100 mg/ml), S. aureus (50 mg/ml), E. coli (400 mg/ml) and P. aeroginosa (200 mg/ml) with mean diameters of inhibition zones for S. aureus and B. cereus being 18.5±0.7 mm and 11.5±0.0 mm respectively. There was a significant difference in antibacterial activity between the two plant ecotypes (p&lt;0.05).

Antibacterial activity of kaolinite/nanoTiO2 composites in relation to irradiation time

The paper addresses laboratory preparation and antibacterial activity testing of kaolinite/nanoTiO2 composite in respect of the daylight irradiation time. Kaolinite/nanoTiO2 composites with 20 and 40wt% of TiO2 were laboratory prepared, dried at 105°C and calcined at 600°C. The calcination caused transformation of kaolinite to metakaolinite and origination of the metakaolinite/nanoTiO2 composite. X-ray powder diffraction, Raman and FTIR spectroscopic methods revealed titanium dioxide only in the form of anatase in all evaluated samples (non-calcined and calcined) and also transformation of kaolinite to metakaolinite after the calcination treatment. Scanning electron microscopy was used as a method for characterization of morphology and elemental composition of the studied samples. A standard microdilution test was used to determine the antibacterial activity using four human pathogenic bacterial strains (Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, Pseudomonas aeruginosa). A lamp with a wide spectrum bulb simulating daylight was used for induction of photocatalysis. The antibacterial assays found all the KATI samples to have antibacterial potency with different onset of the activity when calcined samples exhibited antibacterial activity earlier than the non-calcined. Significant difference in antibacterial activity of KATI samples for different bacterial strains was not observed.

Preparation and evaluation of a novel antibacterial glass-ionomer cement

A novel antibacterial glass-ionomer cement has been developed. Compressive strength (CS) and S. mutans viability were used to evaluate the mechanical strength and antibacterial activity of the formed cement. Compressive yield strength (YS), modulus (M), diametral tensile strength (DTS) and flexural strength (FS) were also determined. All the formulated antibacterial cements showed a significant antibacterial activity, accompanying with an initial CS reduction. The effect of the synthesized antibacterial polymer loading was significant. Increasing loading from 1% to 20% significantly decreased the S. mutans viability from 3% to 50% and also reduced the initial CS (325 MPa) of the formed cements from 19% to 75%. The cement with 5% antibacterial polymer loading showed 142 MPa, 6.9 GPa, 224 MPa, 52 MPa, and 62 MPa in YS, M, CS, DTS and FS, respectively, as compared to 170, 7.1, 325, 60 and 87 for the experimental cement without antibacterial polymer addition and 141, 6.9, 236, 42 and 53 for Fuji II LC. It was also found that the chlorine-containing antibacterial cement showed better CS values than the bromine-containing cement, with no significant difference in antibacterial activity. The antibacterial cement also showed a similar antibacterial activity to Streptococcus mutans, lactobacillus, Staphylococcus aureus and Staphylococcus epidermidis. The human saliva did not affect the antibacterial activity of the cement. The thirty-day aging study indicates that the cements may have a long-lasting antibacterial function.

Seasonal variation in phenolic composition, antibacterial and antioxidant activities of Ulva rigida (Chlorophyta) and assessment of antiacetylcholinesterase potential

The phenolic composition and antibacterial and antioxidant activities of the green alga Ulva rigida collected monthly for 12 months were investigated. Significant differences in antibacterial activity were observed during the year with the highest inhibitory effect in samples collected during spring and summer. The highest free radical scavenging activity and phenolic content were detected in U. rigida extracts collected in late winter (February) and early spring (March). The investigation of the biological properties of U. rigida fractions collected in spring (April) revealed strong antimicrobial and antioxidant activities. Ethyl acetate and n-hexane fractions exhibited substantial acetylcholinesterase inhibitory capacity with EC50 of 6.08 and 7.6 μg mL−1, respectively. The total lipid, protein, ash, and individual fatty acid contents of U. rigida were investigated. The four most abundant fatty acids were palmitic, oleic, linolenic, and eicosenoic acids.

Preliminary comparative analysis of antibacterial effects of activated and non-activated of expired platelet concentrate by disc diffusion method

Platelets release more than 30 cytokines to provide primary hemostatic function. In addition, platelets are also known to release antimicrobial peptides upon activation by thrombin. In this study, comparative analysis of antibacterial activity of activated and non-activated expired platelet concentrate was determined against Gram-positive and Gram-negative bacteria by Kirby-Bauer disk diffusion method. Thrombin was used to prepare activated platelet concentrate. Gram-positive bacteria tested in this study were S.aureus and S.pyogenes and Gram-negative bacteria were E.coli and K.oxytoca. All the bacteria used in this study were sensitive strains from clinical isolates. Activated and non-activated platelet showed no zone of inhibition against S.pyogenes and E.coli. Activated platelet showed antibacterial activity against S.aureus and K.oxytoca with the zone of inhibition of 8.3 ± 0.6 mm and 7.7 ± 0.2 mm, respectively. Zone of inhibition observed in non-activated platelet against S.aureus and K.oxytoca were 7.8 ± 0.4 mm and 7.5 ± 0.3 mm, respectively. These findings showed that no significant differences in antibacterial activity produced by activated and non-activated platelet. However, zone of inhibition observed in activated and non-activated platelet indicate the presence of antibacterial property in expired platelet.

Effect of polymorphism in egg white lysozyme on muramidase and antibacterial activities as well as hatchability in the Japanese quail (Coturnix japonica)

Lysozyme is one of the best characterized antimicrobial proteins in egg white. Three phenotypes of egg white lysozyme in Japanese quail, Coturnix japonica, (namely fast; slow; and the combination, FS) were observed by acid polyacrylamide gel electrophoresis. The fast phenotype showed faster mobility on Acid-PAGE than the slow phenotype. Comparison of the coding sequences for lysozyme derived from the slow and fast phenotypes revealed a nonsynonymous SNP at nucleotide position 115 from the translation initiation site, which alters AA sequence of lysozyme. This nonsynonymous SNP converted glutamine (Q) in the slow phenotype to lysine (K) in the fast phenotype at AA residue 21 of mature lysozyme (Q21K). Here, we investigated the effect of these phenotypes on muramidase activity, antibacterial activity, and hatchability. Muramidase activity toward isolated cell walls of Micrococcus lysodeikticus was in the order: fast allozyme > slow allozyme > chicken (Gallus gallus), but no significant difference was found among the 3 (P > 0.05). Antibacterial activity against live Staphylococcus aureus cells was significantly greater for the fast allozyme than the slow allozyme from 20 h after incubation (P < 0.05). For the antibacterial effects against live Escherichia coli cells, the activity of fast was significantly higher than that of slow at 16 h after incubation (P < 0.05). Hatchability was estimated for reciprocal crosses of Japanese quail with the FF (fast) and SS (slow) genotypes. Hatchability was 92.5% in FF male × SS female crosses and 87.2% in SS male × FF female crosses. A Cochran-Mantel-Haenszel test revealed a significant difference between the crosses (P < 0.05) and indicated that the female-derived slow phenotype led to improved rates of hatching. Our results suggest that the nonsynonymous SNP in Japanese quail lysozyme influences the electrophoretic migration, muramidase activity, and antibacterial activity of the protein, in addition to the hatchability of the eggs. These results demonstrate, for the first time, a significant difference in antibacterial activity and hatchability between 2 lysozyme phenotypes in Japanese quail.

On the Enhanced Antibacterial Activity of Antibiotics Mixed with Gold Nanoparticles.

The bacterial action of gentamicin and that of a mixture of gentamicin and 15-nm colloidal-gold particles onEscherichia coliK12 was examined by the agar-well-diffusion method, enumeration of colony-forming units, and turbidimetry. Addition of gentamicin to colloidal gold changed the gold color and extinction spectrum. Within the experimental errors, there were no significant differences in antibacterial activity between pure gentamicin and its mixture with gold nanoparticles (NPs). Atomic absorption spectroscopy showed that upon application of the gentamicin-particle mixture, there were no gold NPs in the zone of bacterial-growth suppression in agar. Yet, free NPs diffused into the agar. These facts are in conflict with the earlier findings indicating an enhancement of the bacterial activity of similar gentamicin–gold nanoparticle mixtures. The possible causes for these discrepancies are discussed, and the suggestion is made that a necessary condition for enhancement of antibacterial activity is the preparation of stable conjugates of NPs coated with the antibiotic molecules.