Agar Cup Diffusion Research Articles

An In Vitro Study on the Antibacterial Activity of Statins Against the Most Common Bacterial Pathogens Causing Respiratory Tract Infections in a Tertiary Care Hospital.

Introduction The vast pleiotropic effect of statins has intrigued many researchers to select them as potential candidates against bacterial infections. The role of statins against bacterial pathogens remains debatable. This study was undertaken to evaluate and compare the antibacterial effect of commonly available statins against the most frequently isolatedbacterial pathogens causing respiratory tract infections in our tertiary care hospital using sputum as a sample. Materials and methods The study was conducted in the Microbiology Laboratory of our hospital. Drugs including atorvastatin, rosuvastatin, and simvastatin were purchased in pure form from Sigma Aldrich. Dimethylsulfoxide (DMSO) was used as a solvent for all three drugs. The positive controls used were gentamycin and amoxicillin for Gram-negative and Gram-positive bacteria, respectively. Data regarding all the culture and sensitivity results of sputum samples of patients admitted to the Respiratory Intensive Care Unit over the past 12 months were analyzed. The most common bacterial pathogensStaphylococcus aureus, Klebsiella pneumoniae,and Streptococcus pneumoniae isolated from sputum specimens were taken for our study. The antibacterial effect of statins was studied using two methods: the agar cup diffusion method and the broth dilution method. The zone of inhibition and minimum inhibitory concentration of the drugs were calculated and analyzed. Statistical analysis was performed using GraphPad Prism software version 10.2.0. A one-way ANOVAtest was used to determine if there was any statistical difference between the different statins and antibiotic groups. An unpaired t-test was used to determine the statistical difference between the statins. Results and discussion For the agar cup diffusion method, our results displayed a lack of antibacterial activity of all three statinsatorvastatin, rosuvastatin, and simvastatin against all three bacterial strainsStaphylococcus aureus, Klebsiella pneumoniae,and Streptococcus pneumoniae after overnight incubation by agar cup method at concentrations of3.125 μg/ml, 6.25 μg/ml, 12.5 μg/ml, 25 μg/ml and 50 μg/ml, respectively. The zone of inhibition observed was less than 4 mm (resistant) for all the serial dilutions of atorvastatin, rosuvastatin, and simvastatin. For the broth dilution method, the ANOVA test showed amoxicillin and gentamicin to have high statistically significant microbial growth inhibitory activity (p-value< 0.005) compared to atorvastatin and rosuvastatin. Statistically, though atorvastatin showed significant antimicrobial activity compared to normal saline and rosuvastatin,thiswas not considered clinically significant as the antimicrobial activity shown by atorvastatin was very negligible compared to the controls used and did not correspondto the serial dilutions of the drug. Conclusion Atorvastatin, rosuvastatin, and simvastatin lacked antibacterial activity against all three bacterial strains isolated from sputum specimens:Staphylococcus aureus, Klebsiella pneumoniae, and Streptococcus pneumoniae.Hence, the use of statins as an antimicrobial drug for respiratory tract infections has limited applications.

Nitrocellulose for Prolonged Permeation of Levofloxacin HCl-Salicylic Acid In Situ Gel.

Currently, the application of solvent exchange-induced in situ gel is underway for drug delivery to the body target site. Nitrocellulose was attempted in this research as the matrix-forming agent in solvent exchange-induced in situ gel for acne and periodontitis treatments. The gel incorporated a combination of 1% w/w levofloxacin HCl and 2% w/w salicylic acid as the active compounds. In order to facilitate formulation development, the study explored the matrix-forming behavior of different concentrations of nitrocellulose in N-methyl pyrrolidone (NMP). Consequently, their physicochemical properties and matrix-forming behavior, as well as antimicrobial and anti-inflammatory activities, were evaluated using the agar cup diffusion method and thermal inhibition of protein denaturation in the egg albumin technique, respectively. All prepared formulations presented as clear solutions with Newtonian flow. Their contact angles on agarose gel were higher than on a glass slide due to matrix formation upon exposure to the aqueous phase of agarose, with an angle of less than 60° indicating good spreadability. Nitrocellulose concentrations exceeding 20% initiated stable opaque matrix formation upon contact with phosphate buffer pH 6.8. The high hardness and remaining force of the transformed gel indicated their robustness after solvent exchange. Fluorescence tracking using sodium fluorescein and Nile red confirmed the retardation of NMP and water diffusion by the nitrocellulose matrix. From the Franz cell permeation study, these drugs could permeate through neonate porcine skin and tissue of porcine buccal from the nitrocellulose in situ forming gel. Their accumulation in these tissues might enable the inhibition of the invading bacterial pathogens. The developed in situ gels effectively inhibited Staphylococcus aureus, Staphylococcus epidermidis, Propionibacterium acnes, and Porphyromonas gingivalis. Furthermore, the formulations demonstrated an anti-inflammatory effect. The low viscosity of LvSa25Nc makes it appropriate for injectable treatments targeting periodontitis, while the higher viscosity of LvSa40Nc renders it appropriate for topical applications in acne treatment. Therefore, the nitrocellulose in situ gel loaded with combined levofloxacin HCl and salicylic acid emerges as a promising dosage form for treating acne and periodontitis.

Antimicrobial activity of honey

The present study is aimed at determination of antimicrobial activity of honey. Honey is an effective remedy for healing of wounds as it shows antibacterial and antifungal activity. To study the antimicrobial activity of honey, four types of samples were collected from different sources and labelled as S1,S2,S3,S4. These samples were used to study the antimicrobial activity against laboratory cultures of known pathogens such as Pseudomonas aeruginosa, Staphylococcus aureus, Klebsiella pneumoniae, Proteus vulgaris, Candida albicans, Escherichia coli, Shigella spp., Bacillus subtilis, Micrococcus luteus, Micrococcus roseousand Bacillus megaterium. Antimicrobial activity of honey samples was studied by using ditch test method and MIC was determined by agar cup diffusion method. All results were recorded and it was found that S1 and S3 honey samples showed maximum antibacterial activity even at 6 times dilutions.

α-MANGOSTIN/CLOVE OIL-INCORPORATED LAURIC ACID-BASED SOLVENT REMOVAL-INDUCED IN SITU FORMING MATRICES

Typically, the bacteria in periodontal pocket of periodontitis disease are capable of producing a number of virulence factors, which are directly toxic to host tissues or immune cells, or indirectly damage host tissues via induction of inflammatory cytokines. The eradication of these microbes from periodontal pocket is one of crucial processes of periodontitis treatment. The α-mangostin from Garcinia mangostana Linn has the most potent antibacterial activity with less tendency to acquire resistance; therefore, it is interesting for using as active compound for periodontitis treatment. This study focuses on the development of in situ forming matrices (ISM) involving 50% w/w lauric acid, 5% w/w clove oil and different α-mangostin amount in NMP for periodontal drug delivery. Physicochemical properties of ISM were investigated including pH, density, viscosity, surface tension, in vitro matrix formation, and injectability. Antimicrobial activities of formulated ISM against three standard microbes were evaluated using agar cup diffusion methods. The pH and density of all α-mangostin and clove oil-loaded 50% w/w lauric acid matrices was 4.40 ± 0.04 to 4.78 ± 0.20 and 0.960 ± 0.000 to 0.963 ± 0.001 g/cm3, respectively. The increasing α-mangostin amounts significantly increased the viscosity of prepared formulation and injection force. All formulations had low viscosity that it was easy to injection and spreadable in the periodontal pockets. After contact PBS pH 6.8, they transformed as matrix and the hydrophobic manner of clove oil retarded a solvent exchange. These prepared formulations showed the antimicrobial activities against Staphylococcus aureus ATCC 6538, Escherichia coli ATCC 25922, and Candida albicans ATCC 17011. Hence, they are the potential systems for periodontal drug delivery.

In Situ Growth of Biocompatible Biogenic Silver Nanoparticles in Poly-Vinyl Alcohol Thin Film Matrix.

Green synthesis is an eco-friendly approach of nanoparticles fabrication gaining momentum among researches. Nanoparticles are used immensely, due to its small size, physical properties, orientation, which can apparently change the performance of any other material when in proximity. Antibacterial, antioxidant, antifungal, antiviral, anti-inflammatory activities of several nanoparticles capable of wound healing make it a appropriate module for wound dressing materials. Silver nanoparticles (SNPs) are recognized as well established antimicrobial and antiseptic agents, thus considering it as a promising candidate for wound healing process and other applications. Here we report an effective and biological approach of a novel thin film preparation based on polyvinyl alcohol (PVA) with SNPs generated within matrix using leaf extract of Aloe vera as a bioreducing agent. Successful incorporation of SNPs into the polymer matrix, which was confirmed by NTA analysis, TEM, SEM. The characterization results revealed that SNPs were found in range of 10-40 nm. Evaluation of antimicrobial activity on Escherichia coli (ATCC 39403), Staphylococcus aureus (ATCC 25923), Klebsiella pneumoniae (clinical isolates), and Candida albicans (diploid fungus) using agar cup and disc diffusion method confirmed effective performance of the PVA-SNPs film. Average ZOI was observed as 3+2mm, 3+2mm, 4+1mm and 4+1mm respectively. Thin film produced is highly biocompatible to HaCat and L929 cell lines for a defined amount and hence can be used as wound dressing materials. The method used in this study is greener, simple, rapid, and cost effective for producing a biocompatible film with profoundly variable applications in food packaging and health care industries.

Clotrimazole-Loaded Borneol-Based In Situ Forming Gel as Oral Sprays for Oropharyngeal Candidiasis Therapy.

Oral candidiasis encompasses fungal infections of the tongue and other oral mucosal sites with fungal overgrowth and its invasion of superficial oral tissues. Borneol was assessed in this research as the matrix-forming agent of clotrimazole-loaded in situ forming gel (ISG) comprising clove oil as the co-active agent and N-methyl pyrrolidone (NMP) as a solvent. Their physicochemical properties, including pH, density, viscosity, surface tension, contact angle, water tolerance, gel formation, and drug release/permeation, were determined. Their antimicrobial activities were tested using agar cup diffusion. The pH values of clotrimazole-loaded borneol-based ISGs were in the range of 5.59-6.61, which are close to the pH of 6.8 of saliva. Increasing the borneol content in the formulation slightly decreased the density, surface tension, water tolerance, and spray angle but increased the viscosity and gel formation. The borneol matrix formation from NMP removal promoted a significantly (p < 0.05) higher contact angle of the borneol-loaded ISGs on agarose gel and porcine buccal mucosa than those of all borneol-free solutions. Clotrimazole-loaded ISG containing 40% borneol demonstrated appropriate physicochemical properties and rapid gel formation at microscopic and macroscopic levels. In addition, it prolonged drug release with a maximum flux of 370 µg·cm-2 at 2 days. The borneol matrix generated from this ISG obsentively controlled the drug penetration through the porcine buccal membrane. Most clotrimazole amounts still remained in formulation at the donor part and then the buccal membrane and receiving medium, repectively. Therefore, the borneol matrix extended the drug release and penetration through the buccal membrane efficiently. Some accumulated clotrimazole in tissue should exhibit its potential antifugal activity against microbes invading the host tissue. The other predominant drug release into the saliva of the oral cavity should influence the pathogen of oropharyngeal candidiasis. Clotrimazole-loaded ISG demonstrated efficacious inhibition of growth against S. aureus, E. coli, C. albicans, C. krusei, C. Lusitaniae, and C. tropicalis. Consequently, the clotrimazole-loaded ISG exhibited great potential as a drug delivery system for oropharyngeal candidiasis treatment by localized spraying.

Plant growth promotion and lipopeptide-mediated biological control of chilli pathogen Colletotrichum siamense by endophytic Bacillus sp.

Biocontrol is the need of the hour and a necessary replacement for chemical fungicides in controlling pre- and post-harvest crop losses by plant pathogenic fungi. The present study explored an endophytic Bacillus sp. strain (K7) from Jasminum officinale for its plant growth promotion and protection abilities. Bacillus sp. K7 was found to produce IAA, ammonia, siderophores, cellulases, amylases, proteases, and fix atmospheric nitrogen, which promoted seed germination in chilli. Agar cup diffusion assays, MIC and MFC assays, light microscopy, scanning electron microscopy, and infection studies in the chilli fruit model showed that Bacillus sp. K7 possessed strong antifungal activity against Colletotrichum siamense. PCR confirmed that the organism possessed biosynthesis clusters for surfactin biosurfactant lipopeptides. MALDI-TOF-MS of the acid-precipitated extract and whole cells revealed that Bacillus sp. K7 produced at least twelve isoforms of surfactins, iturins, and fengycins. 3D structures of some of the selected lipopeptide molecules were docked against cutinase, a virulence-related protein of C. gloeosporioides species complex, where the docking scores of fengycin, iturin, and surfactin were found to be −6.2, −5.1, −5.1, and −5.8 kcal/mol respectively. The combined in-vitro and in-silico results suggest that Bacillus sp. K7 is a potential biocontrol agent and can be used as a seed protectant, biopesticide, biofertilizer, and anti-food spoilage agent.

Levofloxacin HCl-Incorporated Zein-Based Solvent Removal Phase Inversion In Situ Forming Gel for Periodontitis Treatment.

Zein is composed of nonpolar amino acids and is a water-insoluble protein used as the matrix-forming agent of localized in situ forming gel (ISG). Therefore, this study prepared solvent removal phase inversion zein-based ISG formulations to load levofloxacin HCl (Lv) for periodontitis treatment using dimethyl sulfoxide (DMSO) and glycerol formal (GF) as the solvents. Their physicochemical properties were determined, including viscosity, injectability, gel formation, and drug release. The topography of dried remnants after drug release was revealed using a scanning electron microscope and X-ray computed microtomography (μCT) to investigate their 3D structure and % porosity. The antimicrobial activities were tested against Staphylococcus aureus (ATCC 6538), Escherichia coli ATCC 8739, Candida albicans ATCC 10231, and Porphyromonas gingivalis ATCC 33277 with agar cup diffusion. Increasing zein concentration or using GF as the solvent notably enhanced the apparent viscosity and injection force of the zein ISG. However, its gel formation slowed due to the dense zein matrix barrier's solvent exchange: the higher loaded zein or utilization of GF as an ISG solvent prolonged Lv release. The SEM and μCT images revealed the scaffold of dried ISG in that their % porosity corresponded with their phase transformation and drug release behavior. In addition, the sustainability of drug diffusion promoted a smaller antimicrobial inhibition clear zone. Drug release from all formulations was attained with minimum inhibitory concentrations against pathogen microbes and exhibited a controlled release over 7 days. Lv-loaded 20% zein ISG using GF as a solvent exhibited appropriate viscosity, Newtonian flow, acceptable gel formation and injectability, and prolonged Lv release over 7 days with efficient antimicrobial activities against various test microbes; thus, it is the potential ISG formulation for periodontitis treatment. Consequently, the Lv-loaded solvent removal zein-based ISGs proposed in this investigation offer promising potential as an efficacious drug delivery system for periodontitis treatment by local injection.

Designing and characterization of Yahom buccal mucoadhesive tablets for oral ulcer treatment

Oral ulcer is a common oral mucosal disease that affects about 5–20% of general population, particularly the elderly, and is characterized by recurrent, painful ulcerations and burning sensation. Various possible causes include local, systemic, immunologic, genetic, allergic and microorganisms. Yahom is a Thai traditional medicine that has long been used to treat nausea, vomiting, dizziness and weakness in elderly. Yahom is produced from a variety components of dried medicinal plant parts that are mostly ground into powder dosage form. Ingredients are composed of following crude drugs are common incorporated in Yahom preparations such as clove, terminalia gall, costus root and ceylon ironwood flower which practically and clearly exhibit the potent antioxidant and antimicrobial activities. Therefore, it is interesting to apply Yahom as active component for oral ulcer treatment using appropriate approach such as mucoadhesive tablet. The objective of this study is to develop buccal mucoadhesive tablet consisting of hydroxypropyl methylcellulose (HPMC) and polyvinyl pyrrolidone (PVP) as mucoadhesive polymers in formulations. The impact of various ratios of Yahom: polymer and polymer mixtures were investigated on physicochemical properties of mucoadhesive tablets were investigated including physical properties, disintegration time, water sorption/erosion behaviors and ex-vivo mucoadhesion. In addition, the antimicrobial activities of formulations against two standard microbes were also evaluated using agar cup diffusion methods. Yahom mucoadhesive tablets were successfully fabricated using direct compression tableting technique with good appearance and acceptable physical properties. Different amounts of Yahom and polymer ratios apparently influenced on water sorption, erosion behaviors and hardness of mucoadhesive tablets, resulting in alteration of disintegration time and muco-adhesion properties. In addition, these prepared tablets exhibited the efficient antimicrobial activities against Staphylococcus aureus ATCC 6538 and C. albicans ATCC 10231. Therefore, the buccal mucoadhesive tablets containing Yahom are the potential herbal delivery system for oral ulcer treatment.

Antimicrobial and antitumoral activities of saturated fatty acid solutions

Fatty acids are widely applied in pharmaceutical and cosmetic fabrications. Here, six saturated fatty acids including caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, and stearic acid were tested for the antimicrobial and antitumoral activities. The test for antimicrobial activities of these compound was performed against Staphylococcus aureus DMST 6532, S. aureus ATCC 4330 and S. aureus ATCC 25923, Escherichia coli ATCC 8739 and Candida albicans ATCC 17100 using agar cup diffusion method. The cell viability of each fatty acids was accessed using WST-1 assay against colorectal cancer, HCT116, and liver hepatocellular carcinoma, HepG2 and 1321N1 astrocytoma cell line. The low molecular weight fatty acid such as caprylic acid exhibited higher antibacterial activities whereas the long chains had no or very little on antimicrobial activity. Short-chain fatty acids also exerted more efficient activity against Candida albicans. For the anti-tumoral activity, the results showed the viability promotion of cancer cells at the low concentration of fatty acids tested because most of cancer cells might gain the benefit from the saturated fatty acids as its nutrient and promoted the cell growth and their viability. The cytotoxic of fatty acids was detected at the higher concentration. However, the cytotoxicity potential of the fatty acids relied on concentrations of saturated fatty acid and also type of cell lines tested. These obtained antimicrobial and antitumoral characteristics depending on chain length of these saturated fatty acids are beneficial data for designing drug delivery systems using them as the adjunct components for promoting therapeutic action of main incorporated active compound.

Studies on In-vitro Bioactivity of Icacina trichantha Methanol Seed Extract

Plants are new sources of antioxidative and antimicrobial agents, hence the need to determine and evaluate the antibacterial, antifungal properties and antioxidant activity of medicinal plants. The aim of this study was to investigate antioxidant and antimicrobial potentials of methanol extract of Icacina trichantha. Oliv. (Icacinaceae) seed. In this research work, antioxidant study was done by using various in vitro methods such as: 1-Dipheny-2-picrylhydrazyl (DPPH), 2,2-azinobis (3-ethylbenzthiazoline)-6-sulfonic acid) (ABTS), total antioxidant capacity (TAC), nitric oxide (NO) scavenging, hydrogen peroxide (H2O2) scavenging, ferric reducing antioxidant power, superoxide radical scavenging and hydroxyl radical scavenging assays. Antimicrobial properties were determined using agar cup diffusion method on MRSA, P. aeruginosa, S. typhi, C. krusei, S. dysenteriae, S. pyrogenes, E. coli, K. pneumoniae, C. albicans, and C. tropicalis. The extract of the studied plant exhibited pronounced antioxidant activities in the various antioxidant activity assay tested. Also, the extract had remarkable susceptibility effect on the tested microorganism with the exception of P. aeruginosa, S. typhi and C. tropicalis that were resistant. The findings indicate that the extract was found to be effective free radical quencher, a potent source of natural antioxidants and antimicrobial agents, thus justifying its traditional use in green therapeutics.

Physicochemical and Bioactivity Characteristics of Doxycycline Hyclate-Loaded Solvent Removal-Induced Ibuprofen-Based In Situ Forming Gel.

Modulation with the suppression of infection and inflammation is essential to the successful treatment of periodontitis. An aqueous insoluble hydrophobic anti-inflammatory compound, i.e., ibuprofen (IBU), was investigated in this study as the matrix-forming agent of a doxycycline hyclate (DH)-loaded solvent removal-induced in situ forming gel (ISG) using dimethyl sulfoxide (DMSO) and N-methyl pyrrolidone (NMP) as the solvents. Their physicochemical properties, including pH, density, viscosity, surface tension, contact angle, water tolerance, injectability, mechanical properties, gel formation, and drug release, were determined. Their antimicrobial activities were tested using agar cup diffusion, and their anti-inflammatory activity was assessed using thermal inhibition of protein denaturation of egg albumin. Increasing the IBU content decreased the density, pH, surface tension, and contact angle but increased the viscosity, force and work of injection, and gel formation of IBU-based ISG solution. Although their water tolerance values decreased with the increase in IBU content, the addition of DH and the use of NMP led to high water tolerance. The characterization of the dried gel remnants of ISGs presented no change in IBU crystallinity and thermal properties and confirmed no chemical interaction among the components of ISGs. The obtained transformed IBU matrix prolonged the release of DH and IBU from ISGs over 7 days from its tortuously packed IBU matrix with small pores, and conformed well with Fickian diffusion mechanism. The developed DH-loaded solvent removal-induced IBU-based ISGs exhibited efficient antimicrobial activities against Staphylococcus aureus, methicillin-resistant S. aureus, Escherichia coli, Candida albicans, Porphyromonas gingivalis, and Aggregatibacter actinomycetemcomitans. IBU in formulation promoted the antimicrobial activity of ISGs, whereas DH and NMP promoted the anti-inflammatory activity of ISGs. Consequently, the DH-loaded solvent removal-induced IBU-based ISGs proposed in this study show great potential as an effective bioactive drug delivery system for periodontitis treatment by localized periodontal pocket injection.

PREPARATION AND ANTI-MICROBIAL STUDY OF KASASHWASAVIDHUNANO RASA IN-VITRO

Kasashwasavidhunano Rasa is a drug used in Respiratory disorders in the Indian System of Medicine. It is an herbomineral formulation made up of Parad, gandhak, yavakshara, ruchaka lavana, and maricha churna by triturating in Tulsi patra Swarasa and indicated in Shwasa, Kasa. This action of Kasashwasavidhunano Rasa may be due to its antimicrobial activity so the in vitro antimicrobial activity was assessed by the Agar Disc Diffusion method concerning streptococcus pneumonia and Morxella catarrhal. Objective: To prepare and evaluate the antimicrobial effect of Kasashwasavidhunano Rasa. Method: Kasashwasavidhunano Ras was prepared using the reference of Yogratnakar. Parada (Mercury) and Gandhak (sulfur) were purified and then triturated to form Kajjali. Then raw drugs of maricha were converted into powder form, and all the ingredients i.e. kajjali, maricha churna, yavakshar, ruchaka lavana were mixed and triturated with the help of Tulsi swaras. The final product was in churna from which it was dried and stored. The antimicrobial activity of Kasashwasavidhunano Ras against streptococcus pneumonia and morxella catarrhal bacteria was evaluated using the agar cup diffusion method. Result: Kasashwasavidhunano Ras shows a significant antibacterial spectrum against streptococcus pneumonia and morxella catarrhal. Conclusion: This study shows that Kasashwasavidhunano Ras has antimicrobial potency and it can be clinically used for infectious respiratory disorders.

Repurposing Over-the-Counter Drugs and an Iron-Chelator as Antibacterial Agents

The conventional drug discovery and development process takes a long time and is not financially viable at times. Repurposing or repositioning existing drugs for treating new diseases seems to be a feasible alternative to this problem. Over-the-counter (OTC) drugs such as Rantac (antacid), Draminate (antiemetic), Diclofenac (painkiller), Sinarest (for respiratory disorders), and Desifer (iron-chelator) were included in this study against eight laboratory cultures. Objective: Repurposing Desifer and the OTC drugs as antibacterial agents. Methods: Aqueous preparations of the OTC drugs and Desifer were checked for their antibacterial activity by the ditch plate method. The Agar cup diffusion method was used to determine the MIC of the individual drugs against gram-positive and gram-negative organisms. The synergistic activity of supernatants of OTC drugs with Desifer was determined using agar cup diffusion and micro broth dilution methods. MTT assay was performed with cell lines to determine anticancer and cytotoxic activity. Results and Discussion: Supernatants of drugs used showed antibacterial activity against at least one laboratory culture used. MIC of OTC drugs decreased to one-fourth of individual MIC when used in combination with Desifer, indicating that Desifer enhanced their inhibitory action. Desifer and Diclofenac exhibit anticancer activity, and low cytotoxicity, therefore could be good candidates as chemotherapeutic agents. Conclusion: A combination of the drugs such as Diclofenac and Desifer could be an effective alternative therapy to treat bacterial infections. With emerging drug resistance, Desifer with OTC drugs proves to be a good strategy to enhance the effectiveness of antibacterial drugs.

ANTIBACTERIAL ACTIVITY OF BRYOPHYLLUM PINNATUM AGAINST CLINICAL ISOLATES OF ESCHERICHIA COLI AND KLEBSIELLA PNEUMONIA FROM URINARY TRACT INFECTION PATIENTS

The emergence and spread of resistant strains of bacteria to routinely used antibiotics has made it imperative to continuously search for alternatives that can be used to cure infections, so as not to return to pre-antibiotic era. Plants are known to contain bioactive compounds that can be explored and used in the treatment of infection. The study investigated the antibacterial activity of ethanolic extracts of dried leaf extracts of Bryophyllum pinnatum against clinical isolates of Escherichia coli and Klebsiella pneumoniae from urinary tract infection patients attending Shehu Muhammad Kangiwa Medical Centre. The photochemical screening of the crude extracts of Bryophyllum pinnatum (leaf of life) carried out using standard procedures described by Trens and Jens 2002, revealed the presence of Saponins, Flavonoid, Terpenoids, Alkaloids, Phenol and Tannins . The antibacterial activity of the extracts was carried out using agar cup diffusion method. Four concentrations (200,100, 50 and 25mg/ml) of the extract were tested against Escherichia coli and Klebsiella pneumoniae. The zones of inhibition measured at 200,100, 50 and 25mg/ml were: 00,00,00 and 00 mm respectively. The extracts therefore showed no antibacterial activity against the isolates at all the four concentrations tested. The results of this study proofs that the ethanolic extract of B. pinnatum leaves has no effect on E. coli and K. pneumoniae isolated from patients with Urinary Tract Infection, and hence cannot be used to treat infections caused by these bacteria.

The lipopeptides fengycin and iturin are involved in the anticandidal activity of endophytic Bacillus sp. as determined by experimental and in silico analysis.

In this study, an endophytic Bacillus sp. strain (K7) was isolated from the medicinally important ornamental plant, Jasminum officinale. Biochemical analyses were conducted to evaluate the nature of the extracted product, which displayed strong anticandidal activity against Candida albicans (CA) SC5314, as evident from the results obtained in agar-cup diffusion tests, phase-contrast microscopy, scanning electron microscopy and minimum inhibitory concentration assays. After confirming the presence of the gene clusters encoding the lipopeptides iturins and fengycin in the genome of K7, their corresponding molecular ions were identified using MALDI-TOF-MS. 3D structures of the lipopeptides were downloaded from specific databases and molecular docking was performed against a vital CA enzyme, exo-1,3-beta-glucanase, involved in cell wall remodelling, adhesion to polymer materials and biofilm formation. The docking score of iturins was found to be -8·6 and -8·2 kcal mol-1 and for fengycin it was -9·4 kcal mol-1 , indicating a strong affinity of these cyclic lipopeptides towards exo-1,3-beta-glucanase. The combined invitro and in silico anticandidal studies suggested that these secreted lipopeptides from Bacillus sp. may be used as potential therapeutics against opportunistic and complicated infections of CA.

Antimicrobial activity of Endolichenic fungi isolated from Cryptothecia sp. against some human test pathogens

Cryptothecia sp. is a crustose lichen having varied medicinal properties. The present study aims to isolate and to determine the antimicrobial activity of endolichenic fungi from the surface sterilized lichen thallus of Cryptothecia sp. The isolation was done on three different media i.e., Potato Dextrose Agar (PDA), Malt Extract Agar (MEA) and Water Agar (WA) media. A total of 19 isolates of endolichenic fungi were recovered. The isolates were identified on the basis of colonial morphology and microscopic investigation. Dominant endolichenic fungus was Monilinia sp. (23.33%) followed by Mycelia sterilia (16.66%). Other fungal isolates were Trichoderma sp., Penicillium sp., Aspergillus sp.and Dreschlera sp. The fungal isolates were tested for antimicrobial activity by agar cup diffusion assay against clinically significant human pathogenic test organisms such as Escherichia coli (MTCC 443), Candida albicans (MTCC 227) and Staphylococcus aureus (MTCC 737) procured from IMTECH, Chandigarh. All the isolates exhibited antimicrobial activity against the test pathogens in varying degree. One isolate Penicillium sp., (CRP 3a) showed highest inhibition against all the pathogens. The present study indicated that Cryptothecia sp. harbours various endolichenic fungi with potent antimicrobial activity. Further detailed investigation of the compounds isolated from endolichenic fungi may lead to therapeutic applications as a new source of novel natural products which are helpful to the mankind.

Design and Comparative Evaluation of Vancomycin HCl-Loaded Rosin-Based In Situ Forming Gel and Microparticles.

Vancomycin hydrochloride (HCl) is a glycopeptide antibiotic used to treat serious or life-threatening infections, and it reduces plaque scores and gingivitis in periodontal patients. In this study, vancomycin HCl was incorporated into rosin in situ forming gel (ISG) and rosin in situ forming microparticles (ISM) to generate a local drug delivery system to treat periodontal disease. The physical properties of the ISG and ISM were measured, including pH, viscosity, injectability, adhesion properties, in-vitro transformation, and drug release. Moreover, the effectiveness of antimicrobial activity was tested using the agar-cup diffusion method against Staphylococcus aureus, Streptococcus mutans, Porphyromonas gingivalis, and Escherichia coli. Vancomycin HCl-loaded rosin-based ISG and ISM had a pH value in the range of 5.02–6.48 and exhibited the ease of injection with an injection force of less than 20 N. Additionally, the lubricity effect of the external oil phase of ISM promoted less work of injection than ISG and 40–60% rosin-based ISM showed good emulsion stability. The droplet size of emulsions containing 40%, 50%, and 60% rosin was 98.48 ± 16.11, 125.55 ± 4.75, and 137.80 ± 16.8 µm, respectively. Their obtained microparticles were significantly smaller in diameter, 78.63 ± 12.97, 93.81 ± 10.53, and 118.32 ± 15.61 µm, respectively, because the particles shrank due to the solvent loss from solvent exchange. Moreover, increasing the concentration of rosin increased the size of microparticles. After phase transformation, all formulations had better plasticity properties than elasticity; therefore, they could easily adapt to the specific shape of a patient’s gum cavity. Both developed ISG and ISM presented inhibition zones against S. mutans and P. gingivalis, with ISG presenting significantly more effectively against these two microbes (p < 0.05). The vancomycin HCl-loaded rosin ISG and ISM delayed drug release for 7 days with efficient antimicrobial activities; thus, they exhibit potential as the drug delivery systems for periodontitis treatment.

ANTIMICROBIAL POTENTIALS OF TWO FRESHWATER HETEROCYSTOUS CYANOBACTERIA WESTIELLOPSIS PROLIFICA AND NOSTOCHOPSIS LOBATUS COLLECTED FROM SIMILIPAL BIOSPHERE RESERVE, ODISHA, INDIA

The Similipal Biosphere Reserve, an unique ecosystem in the eastern part of India, occupy the northern boundary of Odisha state, lies between 21°28´ to 22°08´ North latitude and 86°04´ to 86°37´ East longitude, covering a vast area of 5578 sq. km in the district of Mayurbhanj. Westiellopsis prolifica and Nostochopsis lobatus, are a group of heterocystous, true branched, filamentous cyanobacteria belonging to the order Stigonematales, rarely found in the aquatic bodies of this region in the state of Odisha. In the present investigation, an attempt has been made to evaluate the antimicrobial potentials of Westiellopsis prolifica and Nostochopsis lobatus collected from flowing streams of Similipal Biosphere Reserve. The organisms were cultured in nitrogen free BG-11 medium and raised to axenic state. Crude metabolites were extracted from cultured test organisms in late log phase using organic solvents of different polarity viz. methanol and chloroform. The metabolites were tested against some clinically significant microorganisms including bacteria and fungi using agar cup diffusion method and the results of antimicrobial activity of cyanobacteria are summarized. The findings revealed that pattern of inhibition varied with respect to the cyanobacterial strains used, nature of solvent extracts and the pathogenic microorganisms tested. Westiellopsis prolifica was found to be more potent that inhibit all the pathogenic bacteria and fungi both in methanol and chloroform extract. This study illustrates that heterocystous cyanobacteria from freshwater bodies could be a potent source of antimicrobial agents and further characterization of active metabolites and evaluation of their pharmacological potentials are also needed.

Bactericidal effect of Neem (Azadirachta indica) leaf extract on Helicobacter pylori

Aim: The aim of the present study was to investigate the antibacterial effect of ethanolic extract of neem (Azadirachta indica) leaf against Gram-negative, gastric pathogen, Helicobacter pylori (H. pylori). Methodology: Extracts of neem leaf were prepared in different solventslike hexane, dichloromethane, chloroform, ethyl acetate, acetone and ethanol. Antibacterial activity was estimated in terms of zone of inhibition by performing Agar cup diffusion assay. Depending on the diameter of zone of inhibition, ethyl acetate, acetone and ethanol extract of neem leaves were selected for Thin Layer Chromatography. The presence of photochemicals were detected using iodine fumigation. Elution Assay was done to detect the bioactive components of the ethanol extract. Results: Out of sixsolvents used, ethanol extract of neem leavesshowed the maximum zone of inhibition against H. pylori. TLC separation of ethyl acetate, acetone and ethanol extract of plant products showed dark brown bands of phytochemicals on silica-gel G 60 plates. The contact bioautography assay showed a zone of 15 mm. Elution assay and agar cup bioassay was performed against H. pylori and the loading spot showed a zone of 11 mm. Interpretation: The findings of the present study revealed the anti-bacterial potency of ethanolic extracts of neem (Azadirachta indica) leaf against Gram-negative gastric pathogen H. pylori. The ethanolic extract of neem leaf can be used as an effective natural remedy in combating H. pylori infection.