Paper Diffusion Method Research Articles

Uji Aktivitas Sediaan Sampo Antiketombe Ekstrak Kulit Buah Naga (Hylocereus Polyrhizus) terhadap Pertumbuhan Jamur Candida Albicans Secara in Vitro

Dandruff is one of the problems that cause a lack of confidence. The triggering microorganism is Candida albicans. The innovation in the skin of red dragon fruit has the potential as an antibacterial and antifungal because it contains several active compounds such as alkaloids, terpenoids and flavonoids. This study aims to find out at what concentration the anti-dandruff activity on the growth of Candida albicans fungus in the formulation of dragon fruit peel extract shampoo preparation (Hylocereus polyrhizus). This research method is an experimental research using the disc paper diffusion method which consists of making dragon fruit peel extract with the maceration method using 96% ethanol solvent. The extract is formulated in shampoo with concentrations of 20.40 and 80%. The results of this study were in the organoleptis test in the form of a viscous liquid, soft sticky texture, brown and menthol flavor. pH test 6.13, 6.71, 6.39, 5.49. Test the height of the foam 5.8cm, 6.0cm, 6.5cm, 10.3cm. Viscosity test 500 Cp, 612 Cp, 635 Cp, 624 Cp. Homogeneity test is homogeneous. Anti-dandruff shampoo activity test of kontro (+), control (-), concentration of 20%, 40%, 80% with an average of 21.95 mm, 0.00 mm, 22.9 mm, 26.07 mm, 28.52 mm. The conclusion of this study is that the formulation of dragon fruit peel extract shampoo (Hylocereus polyrhizus) has provided an inhibitory effect on the growth of Candida albicans fungus with the strongest inhibitory concentration produced in formulation III with a concentration of 80% of 28.52 mm.

Biodegradation of penicillin G sodium by Sphingobacterium sp. SQW1: Performance, degradation mechanism, and key enzymes

Biodegradation is an efficient and cost–effective approach to remove residual penicillin G sodium (PGNa) from the environment. In this study, the effective PGNa–degrading strain SQW1 (Sphingobacterium sp.) was screened from contaminated soil using enrichment technique. The effects of critical operational parameters on PGNa degradation by strain SQW1 were systematically investigated, and these parameters were optimized by response surface methodology to maximize PGNa degradation. Comparative experiments found the extracellular enzyme to completely degrade PGNa within 60 min. Combined with whole genome sequencing of strain SQW1 and LC–MS analysis of degradation products, penicillin acylase and β–lactamase were identified as critical enzymes for PGNa biodegradation. Moreover, three degradation pathways were postulated, including β–lactam hydrolysis, penicillin acylase hydrolysis, decarboxylation, desulfurization, demethylation, oxidative dehydrogenation, hydroxyl reduction, and demethylation reactions. The toxicity of PGNa biodegradation intermediates was assessed using paper diffusion method, ECOSAR, and TEST software, which showed that the biodegradation products had low toxicity. This study is the first to describe PGNa–degrading bacteria and detailed degradation mechanisms, which will provide new insights into the PGNa biodegradation.

Characterization of Klebsiella pneumoniae carrying the blaNDM-1 gene in IncX3 plasmids and the rare In1765 in an IncFIB-IncHI1B plasmid.

Today, the blaNDM gene is widely distributed on several plasmids from a variety of Gram-negative bacteria, primarily in transposons and gene cassettes within their multidrug-resistant (MDR) regions. This has led to the global dissemination of the blaNDM gene. The determination of class A beta-lactamase, class B and D carbapenemases was performed according to the recommendations of the Clinical and Laboratory Standards Institute (CLSI). Antimicrobial susceptibility testing was performed using both the BioMerieux VITEK2 system and antibiotic paper diffusion methods. Plasmid transfer was then evaluated by conjugation experiments and plasmid electroporation assays. To comprehensively analyze the complete genome of K. pneumoniae strain F11 and to investigate the presence of mobile genetic elements associated with antibiotic resistance and virulence genes, Nanopore and Illumina sequencing platforms were used, and bioinformatics methods were applied to analyze the obtained data. Our findings revealed that K. pneumoniae strain F11 carried class A beta-lactamase and classes B+D carbapenemases, and exhibited resistance to commonly used antibiotics, particularly tigecycline and ceftazidime/avibactam, due to the presence of relevant resistance genes. Plasmid transfer assays demonstrated successful recovery of plasmids pA_F11 and pB_F11, with average conjugation frequencies of 2.91×10-4 and 1.56×10-4, respectively. However, plasmids pC_F11 and pD_F11 failed in both conjugation and electroporation experiments. The MDR region of plasmid pA_F11 contained rare In1765, TnAs2, and TnAs3 elements. The MDR2 region of plasmid pB_F11 functioned as a mobile genetic "island" and lacked the blaNDM-1 gene, serving as a "bridge" connecting the early composite structure of bleMBL and blaNDM-1 to the recent composite structure. Additionally, the MDR1 region of plasmid pB_F11 comprised In27, TnAs1, TnAs3, and Tn2; and plasmid pC_F11 harbored the recent composite structure of bleMBL and blaNDM-1 within Tn3000 which partially contained partial Tn125. This study demonstrated that complex combinations of transposons and integron overlaps, along with the synergistic effects of different drug resistance and virulence genes, led to a lack of effective therapeutic agents for strain F11, therefore its dissemination and prevalence should be strictly controlled.

Virulence genes and antimicrobial resistance of Bacillus cereus in prepackaged pastries sold in Taizhou from 2020 to 2022

To investigate the virulence genes and antimicrobial resistance of Bacillus cereus from the pre-packaged pastries in Taizhou city. 500 pre-packaged patries were collected in taizhou city market. 97 Bacillus cereus strains were detected from them by GB 4789.14-2014 method and identified with 4 houseking genes, then 13 virulence genes were detected by polymerase chain reaction(PCR)method and the antimicrobial resistance of Bacillus cereus to 19 antibiotics was detected by paper diffusion method. The result showed that the contamination rate of Bacillus cereus was 19.4% in 500 pre-packaged pastries. The detection rate of four housekeeping genes groEL, gyr B, rpoB and Vrr were 100%, 94.8%, 97.9% and 96.9%, respectively, and 89.7% at the same time. The virulence gene test result showed that the detection rate of nheABC, entFM, bceT, cytK and hblABCD were 91.8%, 88.7%, 61.9%, 51.6% and 25.8%, emetic virulence genes had the lowest detection rate, ces and EMl were 4.1%, cer was 5.2%. 97 Bacillus cereus strains show different degrees of drug resistance to 14 antimicrobials, the resistance rates to penicillin, ampicillin, cefotaxime and cotrimoxazole were higher than 95%, but they were completely sensitive to streptomycin, vancomycin and chloramphenicol. There is a risk of contamination by diarrhea-type Bacillus cereus and vomiting-type Bacillus cereus in prepackaged pastries in Taizhou. The isolated and identified Bacillus cereus has multiple-drug resistance.

Temporal Shifts in Etiological Agents and Antibiotic Resistance Patterns of Biliary Tract Infections in Sichuan Province, China (2017-2023).

We analyzed the pathogenic bacteria and antibiotic resistance distributions in patients with biliary tract infections (BTI) using samples from the Antimicrobial Resistant Investigation Network of Sichuan Province (ARINSP) to promote the rational use of antibiotics to reduce multidrug resistance. Participating hospitals identified isolates between 2017 and 2023 and conducted antimicrobial susceptibility tests. Isolated bacteria were identified and tested for drug sensitivity using MOLDI-TOF mass spectrometry system, VITEK automated drug sensitivity system and paper diffusion method, and the results were interpreted with reference to CLSI M100 30th edition standards. WHONET 5.6 was used to analyze the results. In total, 25,573 bacterial isolates were collected; 18,134 were Gram-negative (70.9%). The top five most frequently isolated bacteria were Escherichia coli (8,181/25,573; 32.0%), Klebsiella pneumoniae (3,247/25,573; 12.7%), Enterococcus faecium (2,331/25,573; 9.1%), Enterococcus faecalis (1,714/25,573; 6.7%), and Enterobacter cloacae (1,429/25,573; 5.6%). E. coli and E. faecalis slowly declined over time, while K. pneumoniae slowly increased; E. faecium frequency was stable; E. coli resistance to ampicillin was the highest among all antibiotics tested; resistance rates decreased with the addition of sulbactam. K. pneumoniae resistance to aztreonam, imipenem, meropenem, ertapenem, and chloramphenicol remained low. E. cloacae was highly resistant to cephalosporins, especially cefoxitin and cefazolin. E. faecalis' resistance to teicoplanin remained low, decreasing from 6.9% in 2017 to 0.0% in 2019 before stabilizing. The most frequently isolated bacteria from patients with BTIs were Enterobacteriaceae, including E. coli and K. pneumoniae, followed by E. faecium and E. faecalis. Isolates exhibited high resistance to routinely used antibiotics (cephalosporins) and were highly sensitive to tigecycline, carbapenem, amikacin, and vancomycin. The results guide the rational use and continual revision of antibiotic regimens for BTIs to reduce antibiotic resistance.

Comparative study of the antibacterial effects of wound secretions of different cultivars of Chinese fir.

The bark of Chinese fir (Cunninghamia lanceolata), the largest afforestation tree species in the forest areas of southern China, is susceptible to injuries and bites from small animals. The population of small animals has recently increased owing to improvements in the ecological environment across various forested areas, thus increasing the incidence of injuries in the bark of Chinese fir. Following such injuries, the bark secretes light yellow or milky white secretions, the function of which remains unclear. The present study aimed to reveal the antibacterial effect of exudates of different Chinese fir cultivars on five bacterial species. The research involved three-year-old plantations of Taxus chinensis var. koraiensis and Yangkou3 and three-year-old container plantations of Taxus chinensis var. pendula, Yang 061, and Yang 020. The antibacterial effects of exudates were analyzed using the filter paper diffusion method. The minimum inhibitory concentration for each secretion and the bacterial inhibition zone were determined. The exudates of the different Chinese fir bark exhibited notable antibacterial effects on Bacillus subtilis, Salmonella paratyphi B, Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus. However, the extent of these antibacterial effects varied among the different Chinese fir cultivars, as the minimum inhibitory concentrations (MICs) of the exudates against the five bacterial species varied. The mean MIC of Pseudomonas aeruginosa was lower potency, whereas that of Escherichia coli was the lowest. Notably, the antibacterial efficacy of the exudates was mainly influenced by the composition of the secretions rather than the number of secretions, with organic acid compounds and terpenoids potentially contributing to the antibacterial effects against E. coli and Bacillus subtilis, respectively. This study demonstrates the antibacterial effect of wound secretion of different Chinese fir cultivars, highlighting their varying efficacy on different bacterial species. Moreover, the antibacterial ability of the exudates of the strains was mainly determined by the composition of the wound secretions, and there was no noticeable relationship with the number of wound secretions. The results of this study offers a theoretical basis for screen Chinese fir cultivars with high-disease-resistant.

Eco-Friendly Cellulose-Based Nonionic Antimicrobial Polymers with Excellent Biocompatibility, Nonleachability, and Polymer Miscibility.

This study aims to prepare natural biomass-based nonionic antimicrobial polymers with excellent biocompatibility, nonleachability, antimicrobial activity, and polymer miscibility. Two new cellulose-based nonionic antimicrobial polymers (MIPA and MICA) containing many terminal indole groups were synthesized using a sustainable one-pot method. The structures and properties of the nonionic antimicrobial polymers were characterized using nuclear magnetic resonance hydrogen spectroscopy (1H NMR), infrared spectroscopy (FTIR), wide-angle X-ray diffractometry (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), gel chromatography (GPC), and other analytical techniques. The results showed that microcrystalline cellulose (MCC) molecules combined with indole derivatives through an esterification reaction to produce MICA and MIPA. The crystallinity of the prepared MICA and MIPA molecules decreased after MCC modification; their morphological structure changed from short fibrous to granular and showed better thermal stability and solubility. The paper diffusion method showed that both nonionic polymers had good bactericidal effects against the two common pathogenic bacteria Escherichia coli (E. coli, inhibition zone diameters >22 mm) and Staphylococcus aureus (S. aureus, inhibition zone diameters >38 mm). Moreover, MICA and MIPA showed good miscibility with biodegradable poly(vinyl alcohol) (PVA), and the miscible cellulose-based composite films (PVA-MICA and PVA-MIPA) showed good phase compatibility, light transmission, thermal stability (maximum thermal decomposition temperature >300 °C), biocompatibility, biological cell activity (no cytotoxicity), nonleachability, antimicrobial activity, and mechanical properties (maximum fracture elongation at >390%).

Identification and pathogenicity of multidrug-resistant Elizabethkingia miricola isolated from farmed American bullfrogs Rana catesbeiana in China with in vitro screening of herbal antimicrobial agents.

In 2021, an outbreak of an infectious disease characterized by torticollis, cataracts, and neurological disorders caused massive mortality in farmed American bullfrogs Rana catesbeiana in Hubei province, China. We identified the causal agent in this outbreak, characterized its pathogenicity, and screened candidate antimicrobial agents for future disease control. Bacterium was isolated from the diseased American bullfrogs and identified based on biochemical tests, sequence analyses (16S ribosomal RNA; DNA gyrase subunit B), and experimental challenge. Furthermore, antibiotic sensitivity of the isolated strain was detected with Kirby-Bauer paper diffusion method, and the antibacterial activity of 60 traditional Chinese herbal extracts against the isolated strain was evaluated by agar disc diffusion and broth dilution assays. We identified Elizabathkingia miricola strain FB210601 as the causative agent of this disease. The isolated E. miricola strain FB210601 exhibited extensive antibiotic resistance to all tested quinolones, β-lactam antibiotics, and aminoglycosides. Eight herbal extracts exhibited excellent antimicrobial activity against E. miricola FB210601, especially Caesalpinia sappan and Rhus chinensis, with minimal inhibitory concentrations less than 0.2 mg/mL. Additionally, the combined effects of two-component herbal mixtures containing C. sappan or R. chinensis were greater than those of the individual extracts. Our results provide a reference for understanding the pathogenesis of Elizabethkingia infection in frogs. Furthermore, this study will aid in the application of herbal extracts for protection against infections caused by multidrug-resistant Elizabathkingia in the future.

UJI EFEKTIVITAS ANTIBAKTERI SEDIAAN SABUN PADAT TRANSPARAN EKSTRAK ETANOL DAUN CABE RAWIT (Capsicum Frutescens L.) TERHADAP BAKTERI Propionibacterium acne

Cayenne pepper leaves (Capsicum frutescens L.) can traditionally be used as an alternative treatment for acne from natural ingredients. This study aims to determine the effectiveness and concentration of the transparent solid soap formulation ethanol extract of cayenne pepper (Capsicum frustescens L.) leaves in inhibiting the growth of acne-causing bacteria (Propionibacterium acne). The method used in this research is experimental. Making cayenne pepper leaf extract (Capsicum Frutescens L.) by maceration method using 96% ethanol then making a transparent solid soap formulation and testing the effectiveness of antibacterial using disc paper diffusion method against Propionibacterium acnes bacteria by measuring the diameter of the inhibition zone for bacterial growth so that it can known Minimum Inhibitory Concentration (MIC). The concentration of Cayenne pepper leaf extract and the transparent solid soap formula used were (FI) 1%; (FII) 2%; (FIII) 3% and blanks (K+) Ranee soap and (K-) extractless soap. Evaluation of the physical quality of transparent solid soap preparations includes: organoleptic test, pH test, foam power test. From the test results, the average transparent solid soap preparation with a concentration of 1% produced an inhibition zone of 10.7 mm, a concentration of 2% produced an inhibition zone of 11.8 mm, and a concentration of 3% produced an inhibition zone of 12.6 mm. Minimum Inhibitory concentration (MIC) which produced the best ethanol extract of cayenne pepper (Capsicum frutescens L.) leaves was found at a concentration of 1% with a Width of Inhibitory Power (LDH) of 10.7 mm. The One Way Anova test obtained a significance value of 0.000 <0.05, so the results were significant, so there were significant differences between treatments. This means that the use of cayenne pepper leaf extract (Capsicum frutescens L.) has an effect on the growth of Propionibacterium acnes bacteria.

SANCACO COFFEE SYINBIOTIC (PROBIOTIC AND PREBIOTIC) AND ANTIBACTERIAL ASSAY AGAINST Escherichia coli

Robusta coffee is one of the plants used as a drink and has an efficacious content that can be modified to be used as a cure for diarrhea. This research was conducted To determine the effect of synbiotic coffee with a combination of coffee, prebiotic inulin chicory, probiotic B. bifidum, and glucose on the growth and antibacterial activity of the probiotic Bifidobacterium bifidum BRL-130. Organoleptic testing of synbiotic coffee was performed on 30 panelists, then the growth test used the total plate count method, and the antibacterial test used the paper diffusion method. The organoleptic test showed that the selected formula 1 had the highest average taste of 3.76. In the symbiotic coffee growth test, the best results were obtained in week 1 of plain water with a temperature of 40°C with the number of colonies 5.95 x108 CFU/mL. Antibacterial activity test using paper disc diffusion method with a variation of the selected formula 1 treatment control, 2 treatment control pure robusta coffee powder, positive control of ciprofloxacin antibiotic, and negative control of aquadest solvent. The antibacterial activity of synbiotic coffee against E. coli showed that there was an inhibitory response in formula 1 against Escherichia coli bacteria in the first week of storage, 12.3±1.1 mm with strong criteria.

Synthesis of Eco-Friendly Silver Nanoparticles Using Glycyrrhizin and Evaluation of Their Antibacterial Ability.

In the present study, the biosynthesis of silver nanoparticles (AgNPs) and their antibacterial activity against gram-positive and gram-negative bacteria were investigated. Glycyrrhizin (GL) was used as a reducing agent and stabilizer to rapidly prepare the AgNPs. The distinctive absorption peak at 419 nm confirmed the formation of GL-reduced AgNPs. The TEM and particle size analysis shows that the prepared GL-reduced AgNPs were mostly circular with good dispersion and a relatively uniform particle size of 35 nm on average. Fourier transform infrared spectroscopy analysis was performed to identify the possible biomolecules in the capping and active stabilization of the GL-reduced AgNPs. The antibacterial activity of the GL-reduced AgNPs was analyzed with the Oxford cup diffusion method and filter paper diffusion method. The experimental results show that these properties endowed the GL-reduced AgNPs with high antibacterial activity against Escherichia coli and Staphylococcus aureus and lay a foundation for the use of colloidal silver in antibacterial applications. The GL-reduced AgNPs also had stronger antibacterial activity than sodium citrate-reduced AgNPs, which indicates the advantages of GL-reduced AgNPs compared with sodium citrate-reduced AgNPs in inducing bacteriostasis. The cytotoxicity of GL-reduced AgNPs on human kidney epithelial 293A (HEK293) cells was evaluated via the MTT assay. The results show that GL-reduced AgNPs had lower toxicity to HEK293 cells than sodium citrate-AgNPs, which indicates that the as-prepared GL-reduced AgNPs are environmentally friendly.

Pengaruh Waktu Fermentasi Madu dengan Bawang Putih Tunggal (Allium sativum L.) terhadap Daya Hambat Bakteri Propionibacterium acnes

Honey is a substrate that has widely used by the people of Indonesia for treatment, one of which is used to treat acne. Honey has antimicrobial inhibitory power, antimicrobial ability is also found in other natural ingredients, one of it is Single Garlic (Allium sativum L.). Community trend towards the two natural ingredients, one of which is by combining Honey and Single Garlic (Allium sativum L.) using the method of soaking Single Garlic (Allium sativum L.) in Honey. The purpose of the study is to determine the inhibitory power of honey bacteria from soaking / fermentation against propionibacterium acnes bacteria.Testing use the disc paper diffusion method with a sample of fermented Honey and a single Garlic (Allium sativum L.) against the length of honey fermentation time, positive control (Clindamycin 300 mg), and negative control (aquadest). Sample Honey and Garlic Sample (Allium sativum L.) were fermented length time at weeks 1,2,3 and 4. The results showed that the length of time honey fermentation can increase the inhibitory power of the growth of Propionibacterium acnes bacteria by the presence of clear zones around the disc paper. The diameters of honey fermentation in weeks 1,2,3 and 4 are 0.416 mm, 0.65 mm, 0.775 mm and 1.8 mm. The conclusion that the length of fermentation time of Honey and Single Garlic (Allium sativum L.) will increase in diameter in the clear zone of its inhibitory power known in the fourth week to have a maximum inhibitory power of 1.8 mm. Keywords: Fermented honey, Single Garlic,Inhibitory power of bacteria Propionibacterium acnes

Evaluation of Antibacterial Effect on Propionibacterium acnes and Antioxidant Activity of Various Mushrooms, Chinese Herbs, and Plant Essential Oils

Aims: The inhibitory effects of 30 kinds of mushrooms, Chinese Herbs, and plant essential oils on Propionibacterium acnes (P. acnes) were compared to screen high activity antibacterial materials. Furthermore, their minimum inhibitory concentration (MIC), antioxidant activity, total flavonoids, and total phenol content were determined.
 Methodology: The optimal antibacterial samples were screened using the paper diffusion method. The MIC was determined using the microdilution method. The antioxidant activity was evaluated by the 1,1-Diphenyl-2-Trinitrophenylhydrazine (DPPH), Ferric Ion Reducing Antioxidant Power (FRAP), and 2, 2'-Azino-Bis(3-Ethylbenzothiazoline-6-Sulfonic Acid) (ABTS) methods, and the total flavonoids and total phenol contents were determined using Rutin Method and Folin-Ciocalteu Method.
 Results: The MIC of mushroom Tricholoma quercicola and Boletus edulis's extracts were 0.391mg/mL and 3.125mg/mL, showing better antibacterial effects on P. acnes. The Chinese herbs Pericarpium granati and Folium artemisia argyi's extracts (MIC 3.13mg/mL), plant essential oils of Eugenia caryophyllus flower, and Lavandula angustifolia (MIC 61.76mg/mL and 112.7mg/mL) exhibited satisfactory antibacterial effects on P. acnes. Antioxidant evaluation of the above six samples with high antibacterial activity revealed that Folium artemisiae argyi and Pericarpium granati's extract had good antioxidant activity. In addition, the determination results of total flavonoids and total phenols were consistent with the antioxidant activity.
 Conclusion: The above results showed that Boletus edulis, Tricholoma quercicola, Pericarpium granati, and Folium artemisiae argyi could be used as candidate materials for the antibacterial, antioxidant materials, providing a feasible idea for the development of subsequent skincare products for the treatment of P. acnes.

Aktivitas Antibakteri Staphyloccocos aureus dan Salmonella thypi Ekstrak Metanol Anggur Laut (Caulerpa racemosa)

Sea Grape is one type of marine plant that produces active compounds that have the potential as medicinal ingredients that have antibacterial properties to inhibit the growth of bacteria that cause infectious diseases. This study aims to determine the antibacterial activity of sea grapes from Kampung Terih, Nongsa Beach, Riau Islands. The bacterial test used was Staphylococcus aureus and Salmonella typhi. Antibacterial activity testing using the disc paper diffusion method was carried out by measuring the inhibition zone around the disc paper, using a concentration variant of 25%, 75%, 100%. The results showed that sea grape extract was able to inhibit the growth of Staphylococcus aureus bacteria by forming an average diameter at each concentration of 8.4 mm (medium inhibition); 9.1 mm (medium resistance); 15.7 mm (strong resistance); then Salmonella typhi bacteria formed an average diameter at each concentration of 8.3 mm (medium inhibition); 9.3 mm (medium inhibition); 19.9 mm (strong resistance). Sea grape extract has strong potential in inhibiting bacterial growth.

A new δ-valerolactone produced by marine Streptomyces sp. YIM 13591

A new δ-valerolactone compound, named 8-hydroxy invictolide 2 (1), a new natural product 4-hydroxy-3,5-dimethyl-6-(pentan-2-yl) tetrahydro-2H-pyran-2-one (2) together with four known compounds cyclo (L-Pro-L-Tyr) (3), cyclo (D-Pro-L-Tyr) (4), acetyltryptophan methyl ester (5), 2-aminobenzoic acid (6) were isolated from marine Streptomyces sp. YIM 13591. Their structures were elucidated by NMR spectroscopic data, HRESIMS and specific rotation, and the absolute configurations of the stereo centre in lactone ring 1 and 2 were further confirmed by electronic circular dichroism (ECD) calculation. The antimicrobial effects of these compounds were evaluated by the paper diffusion method.

DETERMINATION OF PHENOLIC, FLAVONOID CONTENT, ANTIOXIDANT AND ANTIBACTERIAL ACTIVITIES OF SERI (Muntingia calabura L.) LEAVES ETHANOL EXTRACT FROM NORTH SUMATERA, INDONESIA

Seri (Muntungia calabura L) leaves have various secondary metabolite components and it is necessary to carry out phytochemical screening and determination of their levels as well as in vitro testing of their bioactivity as antioxidants and antibacterials. Extraction was carried out by maceration method with ethanol as solvent. Determination of phenol with Folin-Ciaocalteu reagent was measured at a wavelength of 765 nm, while the levels of flavonoids with AlCl3 reagent were measured at a wavelength of 431 nm using the colorimetric method, antioxidant activity testing with 2,2-diphenyl-1-picrylhydrazyl (DPPH) was measured at a wavelength 517 nm using UV-Vis spectrophotometry, and antibacterial activity testing was carried out on the bacteria Ercherichia coli, Staphylococcus aureus, and Staphylacoccus epidermidis using the disc paper diffusion method with various concentrations of 12.5%, 25%, 50%,75%, DMSO10% for control negative and Chlororamphenicol as a positive control by observing the clear zone in mm. Phenolic content equivalent to 2.258±0.008 mg gallic acid (mg GAE/g dw), flavonoid content 2.476±0.019 mg equivalent to quercetin (mg QE/g dw), antioxidant activity of ethanol extract of M. calabura L. leaves, leaves was 19.004, antibacterial activity against Ercherichia coli, Staphylococcus aureus, and Staphylacoccus epidermidis with a strong category. The ethanol extract of the of Seri (Muntingia calabura, L) leaves contains flavonoids, phenolics and shows activity as an antioxidant with a very strong category and a strong antibacterial category

Cu(II) and Zn(II) complexes incorporated with active analogue fragments molecule of the aristolochic acid: Crystal structure and biological activity

Two complexes, [Cu(MDPAc)2(Phen)(H2O)·H2O] (MDPAc = 3,4-(methylenedioxy)phenylacetic-carboxylate, Phen = 1,10-Phenanthroline) and [Zn(MDPAc)2(2,2′-bipy)] (2,2′-bipy = 2,2′-bipyridine), were synthesized and successfully obtained as single crystals. The single-crystal structures of two complexes and the weak intermolecular force in the crystal were analyzed by Hirshfeld surface analysis. The competitive capacity of the complexes about calf thymus DNA (ct-DNA) was analyzed by fluorescence spectroscopy, and their antibacterial activity was determined by paper diffusion method. The cytotoxicity experiments of the complexes were carried out on two kinds of cancer cell lines (HepG, SKOV-3). The results show that the complexes had anti-tumor activity and cytotoxicity. Finally, molecular docking studies of the complexes with PI3K enzyme indicate that the complexes had beneficial biological activity.

Multigene Phylogeny, Diversity and Antimicrobial Potential of Endophytic Sordariomycetes From Rosa roxburghii.

Rosa roxburghii Tratt. is widely applied in food, cosmetics, and traditional medicine, and has been demonstrated to possess diverse bioactivities. Plant endophytic fungi are important microbial resources with great potential for application in many fields. They not only establish mutualistic symbiosis with host plants but also produce a variety of bioactive compounds. Therefore, in the present study, endophytic fungi were isolated from R. roxburghii, the diversity and antimicrobial activities were evaluated. As a result, 242 strains of endophytic Sordariomycetes were successfully isolated. Multigene phylogenetic analyses showed that these isolates included eight orders, 19 families, 33 genera. The dominant genera were Diaporthe (31.4%), Fusarium (14.4%), Chaetomium (7.9%), Dactylonectria (7.0%), Graphium (4.5%), Colletotrichum (4.1%), and Clonostachys (4.1%). For different tissues of R. roxburghii, alpha diversity analysis revealed that the diversity of fungal communities decreased in the order of root, fruit, stem, flower, leaf, and seed, and Clonostachys and Dactylonectria exhibited obvious tissue specificity. Meanwhile, functional annotation of 33 genera indicated that some fungi have multitrophic lifestyles combining endophytic, pathogenic, and saprophytic behavior. Additionally, antimicrobial activities of endophytic Sordariomycetes against Lasiodiplodia theobromae, Botryosphaeria dothidea, Colletotrichum capsici, Pyricularia oryzae, Rhizoctonia solani, Fusarium oxysporum, Pseudomonas syringae, Pantoea agglomerans, Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa were screened. Dual culture test assays showed that there were 40 different endophytic species with strong inhibition of at least one or moderate inhibition of two or more against the 12 tested strains. The results from the filter paper diffusion method suggested that extracellular metabolites may be more advantageous than intracellular metabolites in the development of antimicrobial agents. Eleven isolates with good activities were screened. In particular, Hypomontagnella monticulosa HGUP194009 and Nigrospora sphaerica HGUP191020 have shown promise in both broad-spectrum and intensity. Finally, some fungi that commonly cause disease have been observed to have beneficial biological activities as endophytic fungi. In conclusion, this study showed the species composition, alpha diversity, and lifestyle diversity of endophytic Sordariomycetes from R. roxburghii and demonstrated these isolates are potential sources for exploring antimicrobial agents.

Inhibitory Effect of Cinnamaldehyde on Main Destructive Microorganisms of Nanhai No. 1 Shipwreck

Nanhai No. 1, a shipwreck in the Southern Song Dynasty, China, has a history of more than 800 years. It was salvaged in 2007 and is now on display in the Guangdong Maritime Silk Road Museum. Due to the fact that the hull is a wooden cultural relic and exposed to the air, the biological corrosion and biodegradation caused by microorganisms are key problems of hull protection. At present, the antimicrobial agent Euxyl® K100 (isothiazolinone) has a significant antimicrobial effect in the field, but it has a certain negative impact on the environment and archeologists. In order to reduce the use of chemical antimicrobial agents, we evaluated the inhibitory effects of cinnamaldehyde on the main destructive microorganisms of Nanhai No. 1. Cinnamaldehyde is the main active component of cinnamon, and has broad-spectrum antimicrobial properties. The paper diffusion method, gas diffusion method and minimum inhibitory concentration experiment were used to detect the inhibitory effects of cinnamaldehyde on the main microorganisms of Nanhai No. 1. We found that cinnamaldehyde had significant inhibitory effects on Bacillus tequilensis NK-NH5, Bacillus megaterium NK-NH10, Bacillus velezensis NK-NH11, Bacillus sp. NK-NH15, Bacillus sp. NK-NH16, Bacillus sp. NK-NH17, Fusariumsolani NK-NH1 and Scedosporiumapiospermum NK.W1-3. At the same time, cinnamaldehyde had more inhibitory effects on fungi than bacteria. Finally, we verified that cinnamaldehyde can effectively inhibit the growth of microorganisms in water, for storing the scattered wood blocks of the Nanhai No. 1 hull through laboratory simulation experiments. Cinnamaldehyde, as an environment-friendly antimicrobial agent, is of great significance to protecting water-saturated wooden relics from microbial corrosion and degradation in the future.

Antibacterial Bioactivity of Some Lactic Acid Bacteria Isolated from Various Egyptian Products

The current research aimed to isolate and screening of antibacterial bioactive lactic acid bacteria (LAB) from different foods such as raw milk, dairy products and fermented meat and evaluate their potential for production of antibacterial substances, namely bacteriocins. Ten samples were collected from different market foods, examined and used for LAB isolation on MRS medium. A total of 71 bacterial isolates were selected based on some variation properties, such as color, shape, size and oxygen requirements. These isolates were confirmed as lactic acid bacteria based on their microscopic observation and chemical properties, i.e. catalase negative and acid producing from glucose fermentation. All selected isolates were grown on MRS medium at 37oC for 48 h, and compared to identified LAB strains, i.e. Lactococcus lactis, Streptococcus thermophilus, Befidobacterium sp, Lactobacillus casi, Lb rhamnosus, Lb. acidophilus, Lb. helveticus and Lb. plantarum. Isolates and strains were surveyed for bacteriocin production as inhibitory activity test. Partial purification of bacteriocin was carried out by salt precipitation method; this method was done by ammonium sulphate 40-60% saturation and centrifuged at 9500 rpm for 20 minutes at 4oC. Some of microbial indicator strains found to test by inhibitory biological activity substance (partial purification of bacteriocin) produced by lactic acid cultures. Indicator strains such as staphylococcus aureus, Listeria monocytogenes and others were grown by nutrient agar at 37o C for 24h. An inhibitory activity test was executed by paper diffusion method. The inhibition effect was examined by form clear inhibition zone around indicator strains. Twenty-eight isolates and the 8 LAB strains showed bioactivities against the tested pathogens. Gram positive indicator bacteria were found to be the most sensitive to inhibitory substances produced by LAB culture as compared to gram negative indicator strains. Staphylococcus aureus was exhibited the highest sensitivity to it. The highest bacteriocins activities were produced by strain Lactobacillus rhamnosus while R5 and S6 from LAB isolates. They were shown broad spectrum against gram positive and gram-negative pathogenic bacteria. Diameters of inhibition zone refer to degree of sensitive between indicator strains and bacteriocin activity