Broad-spectrum Antimicrobial Activity Research Articles

Broad-Spectrum Antimicrobial Activity of Oftasecur and Visuprime Ophthalmic Solutions

Due to the wide etiology of conjunctivitis, the expensive and time-consuming diagnosis requires new therapeutic strategies with broad-spectrum antimicrobial activity and nonselective mechanisms of action. In this context, eye drops could provide an alternative to conventional antimicrobial therapies. Here, we compare the antibacterial and antiviral activity of Oftasecur and Visuprime, commercially available ophthalmic solutions. Cytotoxicity assay was performed on Vero CCL-81 cells by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) test. Antibacterial efficacy was evaluated on Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumoniae by disk diffusion, broth microdilution methods, and time-killing tests. Furthermore, the antiviral activity against HSV-1 was estimated by co-treatment, cell and viral pretreatment and post-treatment, via plaque reduction assay, fluorescence assessment (GFP-engineered HSV-1), and real-time PCR. After 24 h of exposure, Oftasecur and Visuprime showed a volume-inducing 50% of cytotoxicity of 125 and 15.8 μL, respectively Oftasecur and Visuprime induced 90% antibacterial activity in response to mean volume of 10.0 and 4.4 µL for Gram-positive and Gram-negative strains, respectively. Oftasecur exerted bactericidal action on both bacterial populations, while Visuprime was bacteriostatic on Gram-negative strains and slightly bactericidal on Gram-positive bacteria. A major impact on infectivity occurred by exposure of viral particles to the ophthalmic solutions. In detail, 50% of inhibition was verified by exposing the viral particles to 3.12 and 0.84 μL of Oftasecur and Visuprime, respectively, for 1 h. The reduction of the fluorescence and the expression of the viral genes confirmed the recorded antiviral activity. Due to their high antimicrobial efficiency, Oftasecur and Visuprime could represent a valid empirical strategy for the treatment of conjunctivitis.

Synthesis And Anti-Fungal Activity of N'-(3-Bromophenyl)-2-{[5-(4-Methylpyridine-3-Yl)-1,3,4-Oxadiazol-2-Yl] Sulfanyl} Acetohydrazides Derivatives

A series of Pyridine derivatives were prepared and evaluated for, antibacterial and antifungal activities. The title compounds were prepared by condensation of substituted aromatic aldehydes with N'-(3-bromophenyl)-2-{[5-(4-methylpyridine-3-yl)-1,3,4-oxadiazol-2-yl] sulfanyl} acetohydrazides. The structures of all these compounds were confirmed by their spectral studies. Among synthesized compounds (DK-IB, DK-IC, DK-IG, and DK-IH) have shown good anti-fungal activity and Anti-Microbial Activity (500 µg mL-1) when compared to reference drugs Ketoconazole (25µg mL-1) and Chloramphenicol (25 µg mL-1). In this study, few derivatives showed a broad spectrum of antimicrobial activity at low concentrations. The MICs (Minimum inhibitory concentration) of some compounds are 8-16µg mL-1.

In Vitro and In Vivo Development of a β-Lactam-Metallo-β-Lactamase Inhibitor: Targeting Carbapenem-Resistant Enterobacterales.

β-lactams are the most prescribed class of antibiotics due to their potent, broad-spectrum antimicrobial activities. However, alarming rates of antimicrobial resistance now threaten the clinical relevance of these drugs, especially for the carbapenem-resistant Enterobacterales expressing metallo-β-lactamases (MBLs). Antimicrobial agents that specifically target these enzymes to restore the efficacy of last resort β-lactam drugs, that is, carbapenems, are therefore desperately needed. Herein, we present a cyclic zinc chelator covalently attached to a β-lactam scaffold (cephalosporin), that is, BP1. Observations from in vitro assays (with seven MBL expressing bacteria from different geographies) have indicated that BP1 restored the efficacy of meropenem to ≤ 0.5 mg/L, with sterilizing activity occurring from 8 h postinoculation. Furthermore, BP1 was nontoxic against human hepatocarcinoma cells (IC50 > 1000 mg/L) and exhibited a potency of (Kiapp) 24.8 and 97.4 μM against Verona integron-encoded MBL (VIM-2) and New Delhi metallo β-lactamase (NDM-1), respectively. There was no inhibition observed from BP1 with the human zinc-containing enzyme glyoxylase II up to 500 μM. Preliminary molecular docking of BP1 with NDM-1 and VIM-2 sheds light on BP1's mode of action. In Klebsiella pneumoniae NDM infected mice, BP1 coadministered with meropenem was efficacious in reducing the bacterial load by >3 log10 units' postinfection. The findings herein propose a favorable therapeutic combination strategy that restores the activity of the carbapenem antibiotic class and complements the few MBL inhibitors under development, with the ultimate goal of curbing antimicrobial resistance.

Antibiofilm properties of cathelicidin LL-37: an in-depth review.

Notwithstanding ceaseless endeavors toward developing effective antibiofilm chemotherapeutics, biofilm-associated infections continue to be one of the most perplexing challenges confronting medicine today. Endogenous host defense peptides, such as the human cathelicidin LL-37, are being propounded as promising options for treating such infectious diseases. Over the past decennium, LL-37 has duly received tremendous research attention by virtue of its broad-spectrum antimicrobial activity and immunomodulatory properties. No attempt has hitherto been made, as far as we are aware, to comprehensively review the antibiofilm effects of LL-37. Accordingly, the intent in this paper is to provide a fairly all-embracing review of the literature available on the subject. Accumulating evidence suggests that LL-37 is able to prevent biofilm establishment by different bacterial pathogens such as Acinetobacter baumannii, Aggregatibacter actinomycetemcomitans, Bacteroides fragilis, Burkholderia thailandensis, Cutibacterium acnes, Escherichia coli, Francisella tularensis, Helicobacter pylori, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, and Streptococcus pyogenes. Inhibition of bacterial adhesion, downregulation of biofilm-associated genes, suppression of quorum-sensing pathways, degradation of biofilm matrix, and eradication of biofilm-residing cells are the major mechanisms responsible for antibiofilm properties of LL-37. In terms of its efficacy and safety in vivo, there are still many questions to be answered. Undoubtedly, LL-37 can open up new windows of opportunity to prevent and treat obstinate biofilm-mediated infections.

Design of a New Coating Agent Based on Graphene Oxide and Antimicrobial/Spermicidal Peptide (Sarcotoxin Pd) for Condom Coating: New Strategy for Prevention of Unplanned Pregnancy and Sexually Transmitted Infections

In this study, sarcotoxin Pd-functionalized graphene oxide (GO-Pd) was synthesized as a new condom-coating agent. Antimicrobial activity was evaluated by radial diffusion assay (RDA) and absorbance-based methods. Sperm motility and morphology were assessed in different concentrations of designed nanostructures. Peptide stability on the GO structures was assessed by the CD technique. GO-Pd showed the highest contact angle. The results approved that GO-Pd had broad-spectrum antimicrobial activities against examined pathogens, especially vaginal infections such as Candida vulvovaginitis. This antimicrobial activity was more than pristine peptides, vancomycin, and fluconazole. GO-Pd also had a higher inhibitory activity on the sperm motility and viability than pristine peptides. GO-Pd had high stability and activity in all examined conditions. But, naked peptides had low stability and activity after incubation in acidic pH and high temperatures (>38°C). In all tests, GO-Pd showed a significant difference compared to naked peptide. Based on the results, GO-Pd can be used as a condom coating to prevent unplanned pregnancy and sexually transmitted infections.

Understanding the Roles of Host Defense Peptides in Immune Modulation: From Antimicrobial Action to Potential as Adjuvants.

Host defense peptides are expressed in various immune cells, including phagocytic cells and epithelial cells. These peptides selectively alter innate immune pathways in response to infections by pathogens, such as bacteria, fungi, and viruses, and modify the subsequent adaptive immune environment. Consequently, they play a wide range of roles in both innate and adaptive immune responses. These peptides are of increasing importance due to their broad-spectrum antimicrobial activity and their functions as mediators linking innate and adaptive immune responses. This review focuses on the pleiotropic biological functions and related mechanisms of action of human host defense peptides and discusses their potential clinical applications.

Turning on the Antimicrobial Activity of Gold Nanoclusters Against Multidrug-Resistant Bacteria.

In this work, we show that the addition of thiourea (TU) initiated broad-spectrum antimicrobial activity of otherwise inactive D-maltose-capped gold nanoclusters (AuNC-Mal). For example, AuNC-Mal/TU was effective against multidrug-resistant Pseudomonas aeruginosa with a minimum inhibitory concentration (MIC) of 1 μg mL-1 (2.5 μM [Au]) while having 30-60 times lower in vitro cytotoxicity against mammalian cells. The reaction of AuNC-Mal and TU generated the antimicrobial species of [Au(TU)2 ]+ and smaller AuNCs. TU increased the accumulation of Au in bacteria and helped maintain the oxidation state as AuI (vs. AuIII ). The modes of action included the inhibition of thioredoxin reductase, interference with the CuI regulation and depletion of ATP. Moreover, the antimicrobial activity did not change in the presence of colistin or carbonyl cyanide 3-chlorophenylhydrazone, suggesting that AuNC-Mal/TU was indifferent to the outer membrane barrier and to bacterial efflux pumps.

Streptomyces sp. Strain PBR11, a Forest-Derived Soil Actinomycetia with Antimicrobial Potential.

The Actinomycetia isolate PBR11 was isolated from the forest rhizosphere soil of Pobitora Wildlife Sanctuary (PWS), Assam, India. The isolate was identified as Streptomyces sp. with 92.91% sequence similarity to their closest type strain, Streptomyces atrovirens NRRL B-16357 DQ026672. The strain demonstrated significant antimicrobial activity against 19 test pathogens, including multidrug-resistant (MDR) clinical isolates and dermatophytes. Phenol, 2,5-bis(1,1-dimethylethyl), is the major chemical compound detected by gas chromatography-mass spectrometry in the ethyl acetate extract of PBR11 (EtAc-PBR11). The presence of the PKS type II gene (type II polyketide synthases) and chitinase gene suggested that it has been involved in the production of antimicrobial compounds. Metabolic profiling of the EtAc-PBR11 was performed by thin-layer chromatography and flash chromatography resulted in the extraction of two bioactive fractions, namely, PBR11Fr-1 and PBR11Fr-2. Liquid chromatography-tandem mass spectrometry analysis of both the fractions demonstrated the presence of significant antimicrobial compounds, including ethambutol. This is the first report on the detection of antituberculosis drug in the bioactive fractions of Streptomyces sp. PBR11. EtAc-PBR11 and PBR11Fr-1 showed the lowest MIC values (>0.097 and >0.048 μg/mL, respectively) against Candida albicans MTCC 227, whereas they showed the highest MIC values (>0.390 and >0.195 μg/mL, respectively) against Escherichia coli ATCC BAA-2469. The effects of PBR11Fr-1 were investigated on the pathogens by using a scanning electron microscope. The results indicated major morphological alterations in the cytoplasmic membrane. PBR11Fr-1 exhibited low cytotoxicity on normal hepatocyte cell line (CC-1) and the percent cell viability started to decline as the concentration increased from 50 μg/mL (87.07% ± 3.22%) to 100 μg/mL (81.26% ± 2.99%). IMPORTANCE Novel antibiotic breakthroughs are urgently required to combat antimicrobial resistance. Actinomycetia are the principal producers of antibiotics. The present study demonstrated the broad-spectrum antimicrobial potential of an Actinomycetia strain Streptomyces sp. strain PBR11 isolated from the PWS of Assam, India, which represents diverse, poorly screened habitats for novel microorganisms. The strain displayed 92.4% sequence similarity with genes of the closest type strain, indicating that the strain may represent a novel taxon within the phylum Actinomycetota. The metabolomics studies of EtAc-PBR11 revealed structurally diverse antimicrobial agents, including the detection of the antituberculosis drug ethambutol, in the bioactive fraction of Streptomyces sp. PBR11 for the first time. The PBR11 strain also yielded positive results for the antibiotic synthesis gene and the chitinase gene, both of which are responsible for broad-spectrum antimicrobial activity. This suggests that the untouched forest ecosystems have a tremendous potential to harbor potent actinomycetia for future drug discovery.

A Talaromyces Fungal Species with Strong Antimicrobial Activity from Deception Island, Antarctica

Deception Island is well-known for harboring highly diverse microbial communities due to its unique volcanic environment in Antarctica. Most studies focused on bacteria, and relatively little was known about the fungal species on this island. The present study was aimed to determine the antimicrobial production and nutrient utilization profiles of a soil fungus from Deception Island, designated as Im33. Our findings showed that the strain had maximum mycelial growth and sporulation on malt-extract agar (MEA) medium, but it demonstrated the strongest antimicrobial activity in yeast extract-malt extract broth (YMB) medium. Phylogenetic analysis of the internal transcribed spacer 1 and 2 regions showed that it is a species belonging to the genus Talaromyces. It was resistant to cycloheximide concentrations up to 1,000 mg/L and exhibited broad-spectrum antimicrobial activity against Gram-positive and Gram-negative test pathogens, as well as being able to utilize a variety of carbon sources. This is the first report of a Talaromyces species from Deception Island. The capability of the strain to produce broad-spectrum antimicrobial compounds and various enzymes indicated that Antarctic fungi, like their bacterial counterparts, have adopted various adaptation strategies to compete and survive in the extreme environment.

Emerging Trends and Future Direction of Graphene Family of Materials as Potential Antimicrobials: A Critical Review

Graphene research has progressed at an unprecedented rate since 2004 when Novoselov and Geim isolated and described a single sheet of graphene. In fact, the relentless progress in graphene literature over the past decades makes it challenging to diversify research efforts in varied directions. The superior optical, electrical, thermal, and mechanical properties of graphene usher in a broad spectrum of applications that attracts the interest of various scientific domains, including material scientists, physicists, chemists, and biologists. These exceptional properties of the graphene family of materials (Gfam) have inspired researchers to explore a cornucopia of potential applications surrounding graphene and its derivatives in the realm of bacterial, fungal, and viral cells. Herein, we provide an exhaustive discussion of the antimicrobial mechanism of Gfam against different pathogen types: bacteria, fungi, and viruses. In addition, we present the physicochemical differences among members of Gfam and the correlation of their germicidal activities to material properties. A comparative analysis of Gfam’s activities pertaining to bare metals and the enhanced broad-spectrum antimicrobial action of graphene family-based nanocomposites as well as surface coatings are also described. The review analyzes and discusses the present constraints and anticipated future directions that would enable graphene-based nanomaterials to advance as high-performance antimicrobial structures. Thus, Gfam as a robust biocidal material of interest can effectively bridge the gap between academia and industry.

Antimicrobial Coatings: Reviewing Options for Healthcare Applications

Many publications report coatings that exhibit antimicrobial potency applicable to high-touch surfaces and desirable for healthcare settings to contribute to reductions in the occurrence of Hospital Acquired Infections (HAI). In this review, the importance of surface contamination and the transmission of microbes is addressed. The standard strategy to tackle fomites is to implement proper disinfection and cleaning practices and periodically monitor the environment’s cleanliness. However, the probability of recontamination of cleaned surfaces is high. Therefore, an additional first line of defense against pathogen transmission and subsequent infection is the antimicrobial surface that can eliminate or at least repel pathogens, introducing a barrier to the spread of infection. It is a simple concept, but formulating a durable, antimicrobial coating with broad-spectrum antimicrobial and antifouling activities has proven challenging. The challenges and progress made in developing such material are reviewed.

Potential of a methanolic extract of Lawsonia inermis (L.) leaf as an alternative sanitiser in the time of COVID-19 Pandemic and beyond

To harness the antimicrobial properties of a crude methanolic extract of Henna (Lawsonia inermis) leaf as a potential alternative sanitiser, there is the need to test its performance in different solutions. In this work, the effects of distilled water (dH20), Acetate-HCL (AH) Buffer (pH 4.6), Phosphate Buffer Saline (PBS) (pH 7.2) and Tris-HCL (TBH) Buffer (pH 8.6) on the antibacterial and antiviral activity of the extract were assessed. Through standard phytochemical screening and HPLC-MS (LCMS STANDARD 7.M), it was found that the extract consisted of about 30 different compounds including flavonoids. The extent of the antimicrobial activity of the extract in solutions was in the increasing order of AH > dH2O >>>> TBH > PBS. Under the same conditions, reduced antibacterial activity and complete cessation of the antiviral activity of the extract in TBH and PBS was observed. However, in AH and dH20, within 1–5 min, 1 mg ml−1, 0.125 mg ml−1 and 0.0625 mg ml−1 of the extract caused complete inactivation of E.coli (reductions of 8.2 log CFU ml−1), B. subtilis (reductions of 8.2 log CFU ml−1) and MS2 (reductions of 9.7 log PFU ml−1) respectively. The fluorescence microscopy images of the live/dead staining of the inactivated bacterial samples validated the extent of the inactivation. The broad spectrum and high antimicrobial activity of the extract, coupled with the plant not a staple food, has long history of safe use by humans as a medicine and cosmetic, cheaply available in abundance in many regions of the world, thus making the extract a potential candidate as an alternative sanitiser in the time of COVID-19 Pandemic and beyond.

Investigation of tetrasubstituted heterocycles reveals hydantoins as a promising scaffold for development of novel antimicrobials with membranolytic properties

Mimics of antimicrobial peptides (AMPs) have been proposed as a promising class of antimicrobial agents. We report the analysis of five tetrasubstituted, cationic, amphipathic heterocycles as potential AMP mimics. The analysis showed that the heterocyclic scaffold had a strong influence on the haemolytic activity of the compounds, and the hydantoin scaffold was identified as a promising template for drug lead development. Subsequently, a total of 20 hydantoin derivatives were studied for their antimicrobial potency and haemolytic activity. We found 19 of these derivatives to have very low haemolytic toxicity and identified three lead structures, 2dA, 6cG, and 6dG with very promising broad-spectrum antimicrobial activity. Lead structure 6dG displayed minimum inhibitory concentration (MIC) values as low as 1 μg/mL against Gram-positive bacteria and 4–16 μg/mL against Gram-negative bacteria. Initial mode of action (MoA) studies performed on the amine derivative 6cG, utilizing a luciferase-based biosensor assay, suggested a strong membrane disrupting effect on the outer and inner membrane of Escherichia coli. Our findings show that the physical properties and structural arrangement induced by the heterocyclic scaffolds are important factors in the design of AMP mimics.

Characterization, molecular identification, and antimicrobial activity of lactic acid bacteria isolated from selected fermented foods and beverages in Malaysia.

The present work investigated the profile and biodiversity of lactic acid bacteria (LAB) isolated from selected manufactured and homemade fermented foods in Malaysia. A total of 55 LAB were isolated from 20 samples, and identified based on the sequencing of 16S rRNA gene. The LAB isolates were identified as Lacticaseibacillus rhamnosus (34.5%), Lactiplantibacillus plantarum (20%), Limosilactobacillus fermentum (20%), Lacticaseibacillus paracasei (12.7%), Lacticaseibacillus casei (3.6%), Lactobacillus sp. (1.8%), Enterococcus faecalis (3.6%), Enterococcus faecium (1.8%), and Enterococcus durans (1.8%). Majority (94%) of the LAB isolates exhibited broad-spectrum antimicrobial activity against selected foodborne pathogens, and four isolates (L. fermentum SC1001, L. paracasei K2003, and L. rhamnosus KF1002 and MK2003) could produce bacteriocin-like inhibitory substance (BLIS). Lacticaseibacillus paracasei M1001 (homemade mozzarella) exhibited high-temperature tolerance and acid resistance, was homofermentative, and generated good antimicrobial activity, which strongly implied its potential for industrial applications. The present work results would potentially widen our knowledge of LAB diversity in Malaysian fermented foods and provide a potential for their applications in the food industry or other purposes.

Treatment of infection and inflammation associated with COVID-19, multi-drug resistant pneumonia and fungal sinusitis by nebulizing a nanosilver solution

Solutions containing Ag0 nanoclusters, Ag+1, and higher oxidation state silver, generated from nanocrystalline silver dressings, were anti-inflammatory against porcine skin inflammation. The dressings have clinically-demonstrated broad-spectrum antimicrobial activity, suggesting application of nanosilver solutions in treating pulmonary infection.Nanosilver solutions were tested for antimicrobial efficacy; against HSV-1 and SARS-CoV-2; and nebulized in rats with acute pneumonia. Patients with pneumonia (ventilated), fungal sinusitis, burns plus COVID-19, and two non-hospitalized patients with COVID-19 received nebulized nanosilver solution.Nanosilver solutions demonstrated pH-dependent antimicrobial efficacy; reduced infection and inflammation without evidence of lung toxicity in the rat model; and inactivated HSV-1 and SARS-CoV-2. Pneumonia patients had rapidly reduced pulmonary symptoms, recovering pre-illness respiratory function. Fungal sinusitis-related inflammation decreased immediately with infection clearance within 21 days. Non-hospitalized patients with COVID-19 experienced rapid symptom remission.Nanosilver solutions, due to anti-inflammatory, antiviral, and antimicrobial activity, may be effective for treating respiratory inflammation and infections caused by viruses and/or microbes.

Synthesis and evaluation of water-soluble imidazolium salt chitin with broad-spectrum antimicrobial activity and excellent biocompatibility for infected wound healing

Infections caused by bacteria have long constituted a major threat to human health and the economy. Therefore, there is an urgent need to design broad-spectrum antibacterial materials possessing good biocompatibility to treat such infections. Herein, inspired by the good biocompatibility of chitin and antibacterial properties of imidazolium salts, a polysaccharide-based material, imidazolium salt chitin (IMSC), was homogeneously prepared using a facile method with epichlorohydrin as a chemical crosslinker to combine chitin with imidazole to enhance Staphylococcus aureus (S. aureus)-infected wound healing. The characteristics, antimicrobial properties, and biosafety of IMSC were evaluated. The results demonstrated successful grafting of imidazole onto chitin. Furthermore, IMSC exhibited good water solubility, broad-spectrum antimicrobial activity, hemocompatibility, and biocompatibility. Moreover, IMSC enabled complete healing of S. aureus-infected wound in Sprague–Dawley rats within 15 days of application, thus demonstrating that IMSC could reduce wound inflammation and remarkably accelerate wound healing owing to its efficient antibacterial activity and ability to promote collagen deposition in and around the wound area. Therefore, this study provides a promising and potential therapeutic strategy for infected wound healing by synthesizing a water-soluble and broad-spectrum antimicrobial material exhibiting good biocompatibility.

Value added bioactive compounds from fruits & vegetables waste for assessing their antimicrobial activity

Since ancient time, plants and there parts have been used widely against dreadful pathogens due to ability of killing microbes. Waste from fruits and vegetables are pulling in more interest in exploration due to their therapeutic properties such as anti-pathogenic activity. In the present study antimicrobial and cytotoxicity properties of herbal combination prepared from peels of Allium cepa, Cucumis sativus, Citrus reticulata, and Mangifera indica were investigated. The herbal combination was tested for broad spectrum antimicrobial activity against Streptococcus mutans, Bacillus licheniformis, Lactobacillus plantarum, Escherichia coli, Pseudomonas aeruginosa, and Citrobacter freundii. The presence of phytochemical markers such as phenolics and flavanoids were also investigated. The results revealed that the herbal combination exhibited antimicrobial activity against S. mutans, B. licheniformis, L. plantarum, E. coli and moderate against P. aeruginosa and C. freundii. The presence of phenolics (798 ± 1.52µg/g) and flavanoids (355.3 ± 2.081µg/g) was also detected. Also, the herbal combination contains flavanoids such as quercetin and rutin was confirmed with the help of column chromatography, high-performance liquid chromatography (HPLC), fourier-transform infrared spectroscopy (FTIR) and nuclear magnetic resonance spectroscopy (NMR) analysis. The herbal combination helps in the proliferation of L929 cells without affecting their viability was confirmed by MTT assay. The results of the present research suggests the possibility to use herbal combination as source for plausible antibacterial agent which could be isolated and used as a lead candidate for the development of antibacterial drug that help to limit or stop infectious illnesses caused by different pathogenic microbes.

A Study on Aphanamixis polystachya for evaluation of phytochemical and pharmacological properties

The present study was conducted to detect possible chemicals (phytoconstituents), and investigate antioxidant, antimicrobial and thrombolytic activities of the extract of Aphanamixis polystachya (stem bark). Phytochemical screening was carried out using the standard test methods of different chemical group. For investigating the antioxidant activity, two complementary test methods namely DPPH free radical scavenging assay and total phenolic content determination were carried out. For the evaluation of in vitro antimicrobial activity, disc diffusion method, and to determine the thrombolytic activity, the method of Prasad et al., 2007 with minor modifications were used. The bark extracts were a rich source of phytochemicals. In DPPH free radical scavenging test, the Carbon tetra chloride soluble fraction showed the highest free radical scavenging activity with IC50 value 19.86µg/ml. while compared to that of the reference standards ascorbic acid. Aphanamixis polystachya was also found as a good source of total phenolic contents. Moreover, the extracts revealed broad spectrum antimicrobial activity at the concentration of 400 µg/disc. By comparing with the negative control the mean clot lysis % was significant (p value <0.0009). Therefore, further studies are suggested to determine the active compounds responsible for the biological activities of the plant extracts.

The LL-37 Antimicrobial Peptide as a Treatment for Systematic Infection of Acinetobacter baumannii in a Mouse Model.

The antimicrobial peptides (AMPs) played a critical role in the innate immunity of the host and are considered natural sources illustrating a broad-spectrum antimicrobial activity with high specificity and low cytotoxicity. AMPs generally possess a net positive charge and have amphipathic structures. Thus, AMPs can bind and interact with negatively charged bacterial cell membranes, leading to destructive defects in biomembranes and ending in cell death. LL37 is the only human cathelicidin-derived antimicrobial peptide that shows a broad spectrum of antimicrobial activity. To determine the antibacterial efficiency of LL37 in a mouse model of systemic A. baumannii infection, LL37 corresponding gene was expressed in E. coli, purification and refolding situations were optimized. The antimicrobial performance of produced LL-37 against A. baumannii was evaluated in vitro via MIC and Time Kill assays, and its destructive effects on the bacterial cell were confirmed by SEM image. The recombinant LL37 showed strong antibacterial function against A. baumannii at 1.5 μg/mL concentration. Time kill assay showed a sharp reduction of cell viability during the first period of exposure, and complete cell death was recorded after 40 min exposure. Furthermore, in vivo results represented a significant ability of LL37 in the treatment of systematic infected mouse models, and all infected mice receiving LL37 protein survived without no trace of bacteria in their blood samples.

Деквалиния хлорид в терапии вагинальных инфекций

The most common inflammatory and infectious diseases of the lower genital tract include bacterial vaginosis (BV), vulvovaginal candidiasis (VVC), aerobic vaginitis, and mixed infections. Standard modern therapies show acceptable but short-term efficacy in most cases, and high recurrence rates and increased antimicrobial resistance remain an unresolved issue. Moreover, vaginal infections are associated with different adverse outcomes both in terms of higher incidence of infertility among couples and gestational complications, having a serious impact on patients’ quality of life. The determination of appropriate management tactics for these women, especially in mixed infections, is quite a challenge for clinicians. This metaanalysis evaluates the efficacy of topical therapy with antimicrobial antiseptics containing dequalinium chloride for various types of vaginal infections. Objective. To analyze the clinical and microbiological efficacy and safety of dequalinium chloride in the treatment of vaginal infections of different etiologies. Materials and methods. A review of selected scientific publications over the past 40 years on the use of dequalinium chloride in the treatment of vaginal infections with assessing the efficacy and safety of its topical use in women was conducted. A total of 4,783 patients (from 26 studies) were included. Results. Dequalinium chloride is an antimicrobial antiseptic agent with broad bactericidal and fungicidal activity and low systemic absorption after vaginal administration. At the same time, dequalinium chloride has similar clinical efficacy to clindamycin when used topically in the treatment of bacterial vaginosis, and its broad antimicrobial activity appears to be most suitable for the treatment of mixed vaginal infections. In addition, the development of microbial resistance to this drug is unlikely due to its pluripotent mechanism of action and local application. Conclusion. The analysis showed that the current formulation of dequalinium chloride (10 mg vaginal tablets) as 6-day therapy with its broad spectrum of antimicrobial activity and good tolerability offers a safe and effective option for empiric therapy of various vaginal infections in daily practice. Key words: vaginal infections, bacterial vaginosis, vulvovaginal candidiasis, anaerobic vaginitis, dequalinium chloride