ATCC 6538P Research Articles

Microbial Pigment Isolation, Culturing, and Extraction to Use as Textile Dyes

The textile industry is one of the largest worldwide polluters of clean water due to the heavy use of synthetic dyes. These chemicals negatively affect the environment, especially aquatic life due to their toxic and mutagenic properties. Synthetic dyes cause harm to human health such as skin allergies and respiratory sensitization. Several advantages such as ease of extraction, availability, high yields and no seasonal variation make microbial pigments the most ideal source of natural pigments. This study was done to isolate colour pigment producing bacteria and fungi from soil collected from organic farms from various locations in Sri Lanka. Out of 7 soil samples, 3 yielded pigment producing bacteria and fungi. In total, 9 pigment producing bacteria and 3 pigment producing fungi were isolated. Gause’s synthetic agar yielded the most pigmented isolates. Isolates were inoculated in broths and pigment production was observed. Extracellular pigments produced by 5 of the bacterial isolates were extracted by a water-based method. The antibacterial activity of the pigments in their crude and concentrated forms was tested using the well diffusion method against Escherichia coli ATCC 8739 and Staphylococcus aureus ATCC 6538P. Inhibition zone against S. aureus was observed for both crude (12.33±0.58mm) and concentrated pigments (9.67±0.58mm) extracted from purple pigment producing bacterial isolate (BPU). This pigment has the potential to be used in antibacterial textile preparation. Extracted pigments were used to dye scoured cotton fabric with the use of 3% alum as mordant. Pigment from BPU isolate resulted in better coloured fabric.

Screening of antimicrobial activity in venom: Exploring key parameters

The escalating challenge of antibiotic resistance significantly threatens global health, underscoring the critical need for new antimicrobial agents. Venoms, increasingly recognized as reservoirs of bioactive compounds with diverse pharmacological effects, have been the focus of recent research. This work evaluates the use of various screening methodologies in assessing the antimicrobial activities of 185 venoms against some gram positive and gram negative bacteria, including E. coli ATCC 8739, B. subtilis ATCC 6633, P. aeruginosa ATCC 9027, and S. aureus ATCC 6538P species and explores the influence of settings on the findings. Furthermore, the research explored the possibility of purifying antimicrobial molecules from venoms through HPLC. Several fractions demonstrated antimicrobial activity against the tested strains.Our results reveal that the measured antimicrobial efficacy of venoms varies according to:i) venom concentration, ii) the detection method, including microdilution and radial diffusion assays, and iii) the choice of culture medium, specifically LB or MH.This strategy has allowed us, for the first time, to identify antimicrobial activity in: i) Bitis arietans venom against P. aeruginosa ATCC 9027, ii) Naja nubiae and Bothrops lanceolatus against B. subtilis ATCC 6633, P. aeruginosa ATCC 9027, and S. aureus ATCC 6538P, and iii) Hadogenes zuluanus, Mesobuthus caucasicus, Nebo hierichonticus, Opistophthalmus wahlbergii scorpions, and Mylabris quadripunctata beetles against S. aureus ATCC 6538P.These findings highlight venoms potential as effective antimicrobial resources and improve our understanding of key factors critical for an accurate detection of venoms antimicrobial properties.

Enhanced Antimicrobial and Degradable Properties of Silver Nanoparticles‐Reinforced Chitosan‐Indian Gooseberry Films for Sustainable Food Packaging

AbstractThis study focuses on creating a biodegradable film composed of chitosan, Indian Gooseberry (IG) extract, and silver nanoparticles (AgNPs), designed to enhance antimicrobial properties and improve food preservation. The presence of AgNPs and IG extract not only dramatically exhibits 99% efficiency in the antimicrobial activity against Staphylococcus aureus (ATCC 6538P), but also achieves this within a remarkably short time interval of ≈20 min. This potent antimicrobial action is attributed to the synergistic effect between the bioactive compounds in the IG extract and the nanoscale silver particles, which together create a highly hostile environment for microbial growth. Moreover, this synergy contributes to 313.94% water vapor transmittance rate and the complete biodegradability of the composite film (93.42% at the end of the second month), ensuring that it leaves no harmful residues in the environment post‐use. The reinforced film exhibits improved hydrophobicity (55.43%), which is crucial for protecting food products from moisture and extending their shelf life. Specifically, the film has been tested as a packaging material for bread, showing a significant extension in shelf life by effectively preventing mold growth and retaining freshness for an extended period (14 days).

New heterocycles from dehydroacetic acid (DHA). Synthesis, antimicrobial activity, DNA gyrase inhibition, antioxidant activity, and molecular docking study

Dehydroacetic acid (DHA) is a significant heterocyclic molecule whose derivatives are highly prevalent. Thus, a new series of heterocyclic derivatives starting from dehydroacetic acid were synthesized and investigated for their antimicrobial and antioxidant activities. The antimicrobial activity of the twenty-one new compounds was determined against S. aureus ATCC 6538-P, E. coli ATCC 25922, C. albicans ATCC 10231, and A. niger NRRL A-326. Out of twenty one compounds, 7a, 8a, 9, 10d and 14 showed promising in vitro antimicrobial activity. Compounds 7a, 8a, and 10d were equipotent to ciprofloxacin reference drug against S. aureus, while compounds 9 and 14 were 4-fold and 2-fold higher than ciprofloxacin, respectively. For E. coli, compounds 9 and 10d were equipotent to ciprofloxacin whereas compounds 7a, 8a, and 14 were 4-fold, 8-fold, and 2-fold higher than ciprofloxacin, respectively. Regarding C. albicans,7a showed moderate activity with 2-fold lower than nystatin (reference drug). To further analyze the antimicrobial potential of the compounds (7a, 8a, 9, 10d, and 14), their in vitro inhibitory activity against E. coli DNA gyrase was evaluated. The results revealed that compound 8a showed the lowest IC50 required for DNA gyrase inhibition almost similar IC50 to ciprofloxacin. A molecular docking study was established to assess the binding mode of 8a, the most active derivative, with the crystal structure of DNA gyrase B (PDB: 5MMN). 8a demonstrated a good binding mode inside the active pocket of the DNA gyrase B with good binding energy value. Additionally, 8a displayed the highest antioxidant activity compared with ascorbic acid. Collectively, the compound 8a is a highly promising antimicrobial candidate for further studies.

Effective Photogeneration of Singlet Oxygen and High Photocatalytic and Antibacterial Activities of Porous Mn-Doped ZnO-ZrO<sub>2</sub> Nanocomposites

Disperse porous Mn-doped ZnO-ZrO<sub>2</sub> nanocomposites were prepared using the facile polymer-salt method. The effect of Mn content on the crystal structure, composite morphologies, their ability to photogenate the singlet oxygen, luminescence properties, and bactericidal activities were studied. The crystal structure and morphology of these materials were investigated using XRD and SEM analysis. It was found that obtained nanocomposites consist of small (~9 nm) hexagonal ZnO and fine ZrO<sub>2</sub> crystals and the embedding of Mn ions expands the crystal cells of ZnO crystals. Photoluminescence spectra indicate the presence of different structural defects (interstitial Zn ions and oxygen vacancies in ZnO and oxygen vacancies in ZrO<sub>2</sub> crystals). Mn-doped ZnO-ZrO<sub>2</sub> nanocomposites can photogenerate singlet oxygen under visible (λ = 405 nm) irradiation. The increased power density of the exciting blue (λ = 405 nm) light significantly enhances the singlet oxygen photogeneration by prepared composites. The dependence of the intensity of singlet oxygen photogeneration by composites on the power density of exciting radiation (at its variation in the range 0.8 ÷ 1.6 W/cm<sup>2</sup>) is close to linear. Mn-doped ZnO-ZrO<sub>2</sub> composites demonstrate superior antibacterial activity against the gram-positive bacteria <em>Staphylococcus aureus ATCC 209P</em>. It was found that highly dispersed porous Mn-doped ZnO-ZrO<sub>2</sub> nanocomposites are promising for practical environmental and medical applications.

Investigation of novel organic-based anti-microbial agents with polyolefins

This study investigated the anti-microbial efficacy of Nouvex N950-9010 MB, an organic-based master batch, when integrated into polypropylene (PP) and high-density polyethylene (HDPE). The focus centers on its effectiveness against two common bacterial strains: E. coli K-12 MG1655 and S. aureus ATCC 6538P. The master batch was compounded at a 5 wt.% loading concentration with PP and HDPE, and was utilized to create monolayer and multilayer films. The findings reveal significant anti-microbial activity at both 4-hour and 24-hour intervals. SEM analysis confirmed homogeneous mixing and optimal adhesion within the films. Thermal stability, assessed via DSC and TGA, remained consistent, with variations within experimental error margins. Surprisingly, FTIR results indicated no substantial differences between modified and unmodified materials, suggesting that Nouvex N950-9010 MB. preserves material integrity. Mechanical properties, including Izod impact and tensile strengths, remained stable in the modified materials. Moreover, the modified PP and HDPE exhibited improved oxygen and water vapor barrier properties (OTR and WVTR) compared with their neat counterparts. UV spectra validated the non-leachability of Nouvex N950-9010 MB, aligning with the manufacturer’s claims. A groundbreaking revelation from the study is that this master batch functions via reactive oxygen species (ROS), marking a pioneering discovery in the field of novel anti-microbial agents. The research demonstrates Nouvex N950-9010 MB’s potential as a powerful and safe solution for antimicrobial applications, opening new avenues for further exploration and practical implementation.

New strontium-based coatings show activity against pathogenic bacteria in spine infection.

Infections of implants and prostheses represent relevant complications associated with the implantation of biomedical devices in spine surgery. Indeed, due to the length of the surgical procedures and the need to implant invasive devices, infections have high incidence, interfere with osseointegration, and are becoming increasingly difficult to threat with common therapies due to the acquisition of antibiotic resistance genes by pathogenic bacteria. The application of metal-substituted tricalcium phosphate coatings onto the biomedical devices is a promising strategy to simultaneously prevent bacterial infections and promote osseointegration/osseoinduction. Strontium-substituted tricalcium phosphate (Sr-TCP) is known to be an encouraging formulation with osseoinductive properties, but its antimicrobial potential is still unexplored. To this end, novel Sr-TCP coatings were manufactured by Ionized Jet Deposition technology and characterized for their physiochemical and morphological properties, cytotoxicity, and bioactivity against Escherichia coli ATCC 8739 and Staphylococcus aureus ATCC 6538P human pathogenic strains. The coatings are nanostructured, as they are composed by aggregates with diameters from 90nm up to 1μm, and their morphology depends significantly on the deposition time. The Sr-TCP coatings did not exhibit any cytotoxic effects on human cell lines and provided an inhibitory effect on the planktonic growth of E. coli and S. aureus strains after 8h of incubation. Furthermore, bacterial adhesion (after 4h of exposure) and biofilm formation (after 24h of cell growth) were significantly reduced when the strains were cultured on Sr-TCP compared to tricalcium phosphate only coatings. On Sr-TCP coatings, E. coli and S. aureus cells lost their organization in a biofilm-like structure and showed morphological alterations due to the toxic effect of the metal. These results demonstrate the stability and anti-adhesion/antibiofilm properties of IJD-manufactured Sr-TCP coatings, which represent potential candidates for future applications to prevent prostheses infections and to promote osteointegration/osteoinduction.

ИЗУЧЕНИЕ ДЕЗИНФЕКЦИОННОЙ ЭФФЕКТИВНОСТИ НОВОГО СРЕДСТВА НА ОСНОВЕ ТРЕТИЧНЫХ АМИНОВ ПО ОТНОШЕНИЮ К ГРАМПОЛОЖИТЕЛЬНЫМ И ГРАМОТРИЦАТЕЛЬНЫМ МИКРООРГАНИЗМАМ В ЛАБОРАТОРНЫХ УСЛОВИЯХ

It was established that a sample of the disinfectant «STEROX vet» showed disinfection activity against gram-positive and gram-negative microorganisms. Disinfection of rough (wood, concrete) test surfaces artificially contaminated with E. coli str. 1257 occurred at a concentration of 1,5% and exposure of 3 hours, S. aureus str. ATCC 6538-P FDA 209-P – at 2% and exposure of 3 hours, at a consumption rate of 0,5 l/m2, Mycobacterium str. B-5 – at a concentration of 5%, double irrigation with an exposure of 24 hours at a consumption rate of 0,5 l/m2 for each application.

Antimicrobial Activity and Phytochemical Screening of Traditional Medicinal Plants

In Nepal, traditional medicinal plants and herbs have long been relied upon for treating various diseases. This study was aimed to explore the antimicrobial properties of commonly used traditional medicinal plants. This study was conducted from December 2022 to June 2023 at the Department of Microbiology, St. Xavier's College, Maitighar, Kathmandu. In this study, antimicrobial property of 12 plants were tested against four ATCC cultures of bacteria- Staphylococcus aureus (ATCC 6538P), Staphylococcus epidermidis (ATCC 12228), Escherichia coli (ATCC 8739) and Pseudomonas aeruginosa (ATCC 9027). The extracts were prepared using Soxhlet's apparatus with ethanol and distilled water as solvents. The ethanolic extract of S. aromaticum had the highest percentage yield The ethanolic extract of O. sanctum showed highest potential against S. aureus with a zone of inhibition of 21mm. The ethanolic extract of S. aromaticum demonstrated antimicrobial activity against S. aureus, E. coli, P. aeruginosa, and S. epidermidis, with respective zones of inhibition of 18mm, 16mm, 18mm, and 20mm. The distilled water extract of A. marmelos displayed the highest antimicrobial activity against E. coli, with a zone of inhibition of 18mm. Phytochemical screening revealed that both extracts of S. aromaticum had the highest presence of phytochemicals. The ethanol extract of Z. armatum exhibited the highest antibacterial activity, with a minimum inhibitory concentration (MIC) value of 2mg/ml against S. aureus. The study of the selected plants extracts confirmed their efficacy as natural antimicrobials against the tested organisms, suggesting their potential for novel drug development in treating infectious diseases. Int. J. Appl. Sci. Biotechnol. Vol 11(4): 186-196.

Antimicrobial Activity of New <i>N</i>-substituted Amides of Aroylpyruvic Acids and Their Silver Salts

Introduction. An important direction of modern pharmacy is the production of new domestic substances with anti-infectious activity, within the framework of ensuring the technological sovereignty of the state. Optimization of methods for determining antimicrobial activity is an integral part of these studies. Previously obtained silver salts of pyrazoles and pyrazolecarboxamideshad high antimicrobial activity. This work presents the results of determining the antimicrobial activity of new biologically active compounds synthesized by a salt formation reaction with silver ions at the carboxyl group of aroylpyruvic acid amides containing anthranilic acid in the amide fragment.Aim. Obtaining previously unknown amides of aroylpyruvic acids and their silver salts and studying their antimicrobial activity (AMA).Materials and methods. New N-substituted amides of anthranilic acids and their silver salts were obtained by organic synthesis methods. To study their antimicrobial activity, a micromethod of double serial dilutions was used on screening strains of S. aureus ATCC 6538P, E. coli ATCC 25922, as well as E. faecalis ATCC 29212, S. aureus Wood 46, S. abony No. 103/39 for highly active compounds. Additionally, a method of accounting for the results was carried out using the phenomenon of fluorescence in interaction with rezazurin, indicating the presence of living microbial cells.Results and discussion. The presence of antibacterial activity of silver salts 2a and 2b in relation to the studied strains was established: the minimum suppressive concentration (MPC) of compound 2a is 23.4–31.2 micrograms/ml, 2b is 3.9–5.8 micrograms/ml. When taking into account the results of the study of AMA using the phenomenon of fluorescence, it was found that they either coincide with the values of MPC determined visually, or indicate less antibacterial activity. Comparison of these results and seeding of the contents of the wells on a dense nutrient medium with respect to screening strains indicates that the suppression of fluorescence in experimental wells in the range of 99–82 % compared with the control is accompanied by the absence of bacterial growth (bactericidal effect), with fluorescence inhibition of less than 60 %, a pronounced growth of microorganisms is observed. In the intermediate range, the growth of single colonies is observed (bacteriostatic effect).Conclusion. The results of the study showed that the new silver salts of N-substituted amides of aroylpyruvic acids have high antimicrobial activity. The correspondence of the type of antibacterial activity to the degree of fluorescence inhibition was established.

Novel antibacterial nanoscale glass surfaces coated with vanadium pentoxide/phosphorus pentoxide (V2O5-P2O5) thin film by the thermionic vacuum arc plasma

In the present study, vanadium pentoxide/phosphorus pentoxide (VP, 50%V2O5 + 50% P2O5) glasses is synthesized by traditional melt-quenching method, and Thermionic Vacuum Arc (TVA) is used to deposit the VP-bulk glass on high-density polyethylene (HDPE) and glass substrates. Morphological, X-ray diffraction (XRD) and Raman analysis showed VP thin films are homogeneous, uniform and nanosized structures on both substrates, and it has a glass structures. Deposition of the VP thin films significantly (p<0.05) increases the hydrophilicity of HDPE substrates decreasing the water contact angle from 80.57°±4.09° to 33.11°±1.37° Escherichia coli O157:H7 ATCC 35150, Listeria innocua ATCC 33090, and Staphylococcus aureus ATCC 6538P are totally inhibited by both VP-coated substrates after 2-h of contact time. Modified Kirby-Bauer tests prove the antibacterial activity of VP-coated HDPE substrates was higher than VP-coated glass substrates against all bacteria. The highest zone of inhibition (43.33±1.77 mm) is observed against Staph. aureus on VP-coated HDE substrates. The study proves the nanoscale structure of the deposited VP thin films is effective in demonstrating antibacterial activity.

Comparative evaluation of disinfectant efficacy against biofilm-residing microorganisms

Introduction. Bacteria in biofilms (BFs) have increased resistance to antibacterial agents, including disinfectants; however, the efficacy level varies depending on the chosen treatment. Therefore, evaluation of efficacy of main disinfectants against BF-residing microorganisms is of scientific and practical interest.&#x0D; The purpose of the study was to explore the effect of disinfectants from various chemical groups on gram-positive and gram-negative bacteria residing in BFs.&#x0D; Materials and methods. The effect of the following disinfectants has been evaluated: alkyldimethylbenzylammonium chloride (ADBAC), tertiary amine (TA), polyhexamethylene guanidine chloride (PHMG), hydrogen peroxide (HP), chloramine (CA), dichloroisocyanuric acid sodium salt (Na DCC), sodium hypochlorite (HC), ethyl alcohol (EA), glutaraldehyde (GA)) against Pseudomonas aeruginosa ATCC 15442 and Staphylococcus aureus ATCC 6538-P BFs. BFs were grown in 96-well plates at 37ºC for 24 hours and then exposed to biocide solutions. The efficacy of disinfectants was evaluated by the number of remaining viable cells and BF relative density.&#x0D; Results. The analyzed bacterial strains formed moderate BFs; the average number of viable cells in BFs was 6.51 ± 0.19 lg. The viable bacterial cell counts in BFs reduced by more than 4 lg when exposed to HP solutions at a concentration of 6%, Na DCC solution — 0.1% (by active chlorine), HC — 1% (by active chlorine), CA – 1% (by product), PHMG — 0.05%, TA — 1.0 %. The BF density decreased by more than 70%. ADBAC solutions at concentrations of 0.1–1.0%, TA — 0.05%, HP — 3%, Na DCC solution — 0.05% (by active chlorine) caused a 2-lg reduction in viable cell counts in BFs. The efficacy of chlorine-active compounds and HP increased when 0.5% sulfonol was added. GA (0.25–1.00%) and EA (40–70%) solutions were ineffective against BF microorganisms.&#x0D; Conclusion. A promising potential in combating microbial biofilms is demonstrated by disinfectants from the group of oxidizing agents (chlorine-active and oxygen-containing), TA and PHMG; using ADBAC as an individual compound is ineffective; aldehydes and alcohols are unable to destroy BFs and eliminate microorganisms in them.

Antimicrobial and Antioxidant Activity Screening of Mushrooms Growing in the Leningrad Region

Introduction. The emergence of new strains of microorganisms that are multidrug resistant (MDR) in relation to the antimicrobial drugs used is one of the pressing problems of modern medicine. To prevent an increase in MDR-related deaths, the search for new antibiotics and their introduction into medical practice must be continuously ongoing. Infectious diseases are also accompanied by cell damage and the development of free radical oxidation processes, therefore the search for new antioxidants is also an important task. Considering the powerful biosynthetic potential of basidiomycetes, this group of fungi has every prospect of becoming a new source of biologically active substances in general, as well as antibiotics and antioxidants in particular. Cap mushrooms, represented mainly by basidiomycetes, number about 14,000 species and are an accessible source of raw materials for the search for promising antimicrobial compounds and antioxidants.Aim. Study of the antioxidant and antimicrobial activity of total extracts obtained from cap mushrooms against Escherichia coli, Staphylococcus aureus and Candida albicans and assessment of the suitability of cap mushrooms as a natural source of substances with antimicrobial and antioxidant activity.Materials and methods. The antifungal and antibacterial activity of the extracts was determined by the micromethod of two-fold serial dilutions in a liquid nutrient medium in 96-well plates in duplicate. The study of this type of biological activity was carried out against reference (type) strains Staphylococcus aureus ATCC 6538-P, Escherichia coli ATCC 25922, Candida albicans NCTC 885-653. To study antioxidant activity using DPPH, we used alcoholic extracts from the fruiting bodies of mushrooms obtained by maceration with 96 % ethanol at a ratio of raw materials to extractant of 1 to 8 for 24 hours, an aqueous solution of ascorbic acid (vitamin C) and an ethanol solution of Trolox.Result and discussion. In relation to S. aureus, a representative of gram-positive flora, the studied extracts of cap mushrooms showed low activity, on average about 2500 or 5000 μg/ml. In relation to E. coli, a representative of gram-negative flora, 8 % of the studied cap mushroom extracts showed an average activity of about 1250 μg/ml. The largest number of cap mushroom extracts – 19% of all studied species – showed activity against the yeast micromycete C. albicans. The highest activity against C. albicans was observed in extracts of the mushrooms Cantharellula umbonata with an MIC of 625 μg/ml, Cortinarius olivaceofuscus with an MIC of 625 μg/ml, and Hypomyces chrysospermus with an MIC of 312 μg/ml. During screening of antioxidant activity, the studied extracts were divided into three groups: with high (more than 50 % PPR), medium (from 15 to 50 % PPR) and low (less than 15 %) antioxidant activity. It was shown that the sum of phenolic compounds significantly correlates with the level of antioxidant activity in all three groups, but in the groups with medium and low antioxidant activity there are also other non-phenolic groups of compounds that make a significant contribution to the total antioxidant activity.Conclusion. Cap mushrooms are a promising source of biologically active substances with antifungal and antioxidant activity.

Evaluation of Antimicrobial Activities of Salvia verbenaca

The antimicrobial activity of several extracts and fractions of Salvia verbenaca L. (Lamiaceae) was investigated by disc diffusion and broth microdilution methods against Escherichia coli ATCC 10536, Staphylococcus aureus ATCC 6538P, Klebsiella pneumoniae UC57, Micrococcus luteus La 2971, Micrococcus flavus ATCC 14452, Proteus vulgaris ATCC 8427, Pseudomonas aeruginosa ATCC 27853, Listeria monocytogenes ATCC 19115, Mycobacterium smegmatis CCM 2067, Bacillus cereus ATCC 7064, Bacillus subtilis ATCC 6633, Candida albicans ATCC 10231, Cryptococcus neoformans ATCC 90112, Kluyveromyces fragilis NRRL 2415 and Rhodotorula rubra DSM 70403. The methanol extract, butanol and chloroform fractions have shown potential antimicrobial effects against some bacteria and the yeast cultures tested, with grown inhibition area diameters in the range 10.8 – 22.4 mm, and MIC values between 0.03 and 0.34 µL/mL. The results of the study support the use of the plant in traditional medicine.

Identification and characterisation of antimicrobial compound produced by probiotic Alkalihalobacillus clausii 088AE.

In the present study, Alkalihalobacillus clausii 088AE was evaluated for the production of antimicrobial compounds, their characterisation, and identification. The results showed that, 48-h-old A. clausii supernatant is able to inhibit the growth of indicator bacteria Micrococcus luteus MTCC 106T (7.0 ± 0.51 mm). The cultivation of 088AE on solid media along with XAD16N beads for 5 days, and isopropanol extraction of antimicrobial compound thereof showed enhanced antimicrobial activity (19.67 ± 0.58 mm) against indicator strain. Further purification with a reversed-phase C18 cartridge yielded a powder with 389.12 ± 10.08 μg of protein per mg. The UV spectra of the sample revealed the characteristic aromatic amino acid peaks at 262 and 276 nm. The results of triple-quadrupole mass spectrometry showed a peak of 1055 m/z, confirming the existence of 10542+, i.e., 2108 Da, suggestive of class I lantibiotic clausin. Furthermore, in silico analysis confirmed the presence of genes responsible for the production of lanthipeptide clausin. The clausin is stable in the presence of proteases (trypsin and pepsin), high temperature (100 °C), pH up to 11 and showed antimicrobial activity against Listeria monocytogenes ATCC 19115, M. luteus, and Staphylococcus aureus ATCC 6538P. Therefore, it could be useful to control gut infections caused by Gram-positive pathogens.

Synthesis and Antibacterial Activity of Azo-Sulfa-Based Disperse Dyes and Their Application in Polyester Printing

For conjugating sulfa drug moieties with Schiff’s bases scaffold in the same build through an azo linker to take advantage of the bioactive feature of both motifs, we designed and synthesized a series of bioactive disperse dyes. The target disperse dyes, methyl 2-(E-2-hydroxy-5-((E)-(4-sulfa-derivative) diazenyl)benzylidene) hydrazine-1-carbodithioates 4a–e have been synthesized via the acidic reaction of azo dyes 3a–e with methyl hydrazine carbodithioate. Structures of the synthesized dyes were clarified based on their spectral and elemental analyses. The effectiveness of the dyes was initially tested as an antibacterial toward Staphylococcus aureus ATCC 6538-P and Escherichia coli ATCC 25933. Dyes that were proven to be effective against bacteria have been used as disperse dyes to print polyester fabrics. The color properties of the dyes and their fastness properties counting washing, perspiration, light, rubbing, and sublimation fastness were also examined. The printed polyester fabrics were evaluated for their antibacterial activity via colony-forming unit (CFU) technique. Fabric samples treated with 4c, 4d, and 4b had promising anti-Gram-positive activities against S. aureus. Whereas 4c-, 4d-, and 4b-treated fabrics exhibited moderate anti-Gram-negative activities against the test bacterium E. coli.

Determination of Chemical Composition and Antimicrobial Activity of the CO2 Extract of Eryngium planum L.

The article presents parameters for obtaining a carbon dioxide extract from the subterranean part of Eryngium planum that contains a valuable set of organic substances and has a certain antimicrobial effect. Methods. Raw materials were collected in the Almaty region (Republic of Kazakhstan). The CO2 extract of Eryngium planum herbs was obtained under subcritical conditions. A gas chromatograph with a mass spectrometric detector was used to determine the compositional breakdown of the extract. Antimicrobial activity was determined by two methods: the micromethod of serial dilutions and the disk-diffusion method. Three microbial test strains were used: Staphylococcus aureus ATCC 6538-P, Escherichia coli ATCC 8739, and Candida albicans ATCC 10231. Results. To extract biologically active substances from the subterranean part of Eryngium planum L., we have chosen carbon dioxide extraction technology, a technology for processing carbon dioxide (CO2) raw materials, which allows us to extract various substances in high concentrations. Carbon dioxide extraction technology is an effective and environmentally safe way to isolate various biologically active substances contained in medicinal plant raw materials. In the composition of the CO2 extract of Eryngium planum L. 43 components were identified, the main of which are α-linolenic acid, 8.30%; myristic acid, 6.40%; caryophyllene, 6.92%; spatulous, 6.62%; and other main identified compounds and their percentage. Conclusions. The study showed that the CO2 extract of Eryngium planum L. contains biologically active compounds that have a pronounced antimicrobial effect against clinically significant microorganisms, such as Escherichia coli, Staphylococcus aureus, and Candida albicans.

Bacterial composition of refrigerators in households and inactivation of airborne Staphylococcus aureus using a TiO2-UVLED module in a 512 L aerobiology chamber

This study aimed to investigate the microbiota in the air and on the surface of a refrigerator and to inactivate aerosolized Staphylococcus aureus using a TiO2-UVLED module. A total of 100 L of the air and 5000 cm2 surfaces in seven household refrigerators were collected using an air sampler and a swab, respectively. Samples were subjected to microbiota analysis as well as quantitative analyses of aerobic or anaerobic bacteria. The level of airborne aerobic bacteria was 4.26 log CFU/vol (100 L), while that of surface aerobic bacteria was 5.27 log CFU/surface (5000 cm2). PCoA based on the Bray-Curtis metric revealed that the bacterial composition differed between samples collected from refrigerators with and without a vegetable drawer. Moreover, pathogenic bacteria containing genera and order from each sample were found, such as Enterobacaterales, Pseudomonas, Staphylococcus, Listeria, and Bacillus. Among them, Staphylococcus aureus was determined to be a core hazardous pathogen in air. Therefore, three S. aureus strains isolated from the air in refrigerators, as well as a reference strain of S. aureus (ATCC 6538P), were inactivated by a TiO2-UVLED module in a 512 L aerobiology chamber. All aerosolized S. aureus were reduced over 1.6 log CFU/vol after treatment with TiO2 under UVA (365 nm) light at 40 J/cm2. These findings suggest that TiO2-UVLED modules have the potential to be used to control airborne bacteria in household refrigerators.

Synthesis, Cytotoxicity, Antibacterial and Antioxidant Activity of New 2-Substituted Benzimidazole Containing 1,2,4-Triazoles

The development of a potent new drug with high biological activity is a challenge in drug design and is of strategic importance. Due to the increasing resistance of pathogens on the available drugs, there is always a demand for designing a potent drug with high biological activity. The pharmacological effects have been observed in compounds containing different moieties of pharmaceutical importance such as triazole, Schiff’s base, benzimidazole.Triazole thione, Schiff’s bases, and two new compounds containing three pharmacophores viz. triazole, benzimidazole, and Schiff base incorporated in a single compound were prepared by applying different synthetic reactions. Different spectroscopic methods, including FT-IR, UV-vis, 1H-NMR, and 13C-NMR, were used to confirm the structure of the prepared compounds. All compounds exhibited moderate antibacterial activity against Staphylococcus aureus (ATCC 6538P) and Staphylococcus epidermidis (ATCC 1228). Antioxidant activity was carried out by DPPH radical scavenging test and among the tested five compounds, the IC50 value of 4-amino-3-(2-hydroxyphenyl)-1H-1,2,4-triazole-5(4H)-thione was found to be 32.364 μg.mL-1 which is closer to the ascorbic acid that was found to be 28.546 μgmL-1. All tested compounds were toxic against brine shrimp where 2-(5-((1H-benzo[d]imidazol-2-yl)thio)-4-((4-chlorobenzylidene) amino)-4H-1,2,4-triazol-3-yl) was comparatively more toxic (LC50= 26.827 μgmL-1).

Evaluation on Antimicrobial Activity of The Lichen Pleurosticta acetabulum

In this study, the ethanol extract of the lichen Pleurosticta acetabulum (Neck.) Elix &amp;amp; Lumbsch (Parmeliaceae) was investigated for their antimicrobial activity against various microorganisms by the disc diffusion method. Mycobacterium smegmatis CCM 2067, Micrococcus luteus CCM 169, Staphylococcus aureus ATCC 6538P, Proteus vulgaris ATCC 8427, Pseudomonas aeruginosa ATCC 27853, Listeria monocytogenes ATCC 15313, Klebsiella pneumoniae UC57, Bacillus cereus ATCC 7064, Escherichia coli ATCC 10536, Rhodotorula rubra DSM 70403, Candida albicans ATCC 10231 and Kluyveromyces fragilis ATCC 8608 were used as test microorgams. We have found that the ethanol extract of the lichen has a potential antimicrobial effect against all tested microorganisms, forming inhibition zones between 12.6-22.4 mm, as compared with the standard antibiotics. Notably, the extract has a strong effect against Escherichia coli and Staphylococcus aureus, especially Candida albicans. In conclusion, P. acetabulum may assist in the discovery of new antimicrobial agents that can serve as selective agents or in the preparation of new combined therapeutic drugs. However, the effect of this lichen species on more pathogenic organisms should be investigated and further and detailed pharmacological and toxicological studies should be conducted.