Agar Diffusion Disc Method Research Articles

Antibacterial activity for Tin-cephalexin Schiff bases against Bacillus Pumilus and Candida albicans

In the current study, cephalexin and two beta-lactam antibiotics were combined with four distinct aldehydes: 3-hydroxybenzaldehyde, 4-dimethylaminobenzaldehyde, 4-methoxybenzaldehyde, and 4-bromobenzaldehyde, to synthesize Schiff bases. The reaction between the free amino group of the acylamino side chain and the aldehydes resulted in the formation of four Schiff bases within the medication. Comprehensive characterization and surface examination were performed on each Schiff base. The biological activity of the synthesized compounds against Bacillus Pumilus (Gram-positive bacteria) and Candida albicans (fungus) was evaluated using the agar diffusion disc method. The antibacterial screening tests revealed that the Schiff bases exhibited enhanced antibacterial activity against these microorganisms, indicating superior efficacy compared to the parent drugs. However, no significant inhibitory effect on the tested fungus was observed.

Antimicrobial resistance profile of gram‐positive isolates belonging to the microbiota of non‐human primates

The aim of this work was to identify gram-positive bacteria and their respective resistance profiles of free-living capuchin monkeys. For this, 15 Sapajus nigritus were captured in a municipal urban park in the northern region of the state of Paraná, Brazil, and under pharmacological restraint, samples were collected with sterile swabs from the oral, rectal, ocular, nasal, and auricular regions. After isolation of the 22 gram-positive bacteria, each isolate was subjected to the catalase and coagulase tests for presumptive identification. Subsequently, phenotypic tests for bacterial resistance were performed using the agar diffusion disc method. The samples resistant to oxacillin were submitted to the PCR technique to search for the mecA gene. Of the 22gram-positive cocci of these two (9.09%) are Streptococcus spp. and twenty (90.91%) Staphylococcus spp. Among Staphylococcus spp. three (13.64%) were coagulate-negative (CoNS) and seventeen (86.36%) coagulate-positive (CoPS). Of the antimicrobials tested, enrofloxacin had the best performance, with only one (04.54%) isolate resistant to it, on the other hand, the antimicrobials with the lowest performance were cefotaxime and penicillin with 19 (82.36%) and 18 (81.81%) resistant isolates, respectively. Only five isolates had MAR less than 0.2, being one ocular, one oral, and three nasal, they had multiple resistance index varied between 0.07 and 0.92, with an average of 0.45 and a mode of 0.3. Among the samples with the highest resistance index, a positive coagulase Staphylococcus stood out, being intermediate to gentamicin and resistant to other antibiotics and an intermediate streptococcus to gentamicin, enrofloxacin, and resistant to other antibiotics. No sample was positive to mecA gene. Future studies should be conducted to identify the Staphylococcus species, the high rate of antimicrobial resistance of the monkeys in this study suggests that Grooming's behavior may be contributing to the sharing of the resistant microorganism among the members of this group of primates.

تحضير,تشخيص ودراسة الفعالية البايولوجية لبعض مركبات قواعد شف و3,1- اوكسازبين المشتقة من دواء السلفا ميثاكسازول

This study including synthesis of some new Schiff bases compounds [1‐6] from the reaction of Sulfamethoxazole drug with some aromatic aldehydes in classical Schiff base method then treatment Schiff bases with succinic anhydride to get oxazepines rings [7-11]These derivatives were characterized by melting point, FT‐IR, 1H NMR and mass spectra. Some of synthesized compounds were evaluated in vitro for their antibacterial activities against three kinds of pathogenic strains Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa by agar diffusion disk method, and against the fungal species (Candida). The results showed that some of these derivatives have good antibacterial activities compared to biological activity of parent drug.

Extraction of PLA2 and antibacterial activity test of lionfish (Pterois volitans) spine venom

The population of Pterois volitans has caused significant damage to other fish populations and coral reef ecosystems. Population control of P. volitans consumes a considerable cost so that the utilization of these fish needs to be sought to be useful along with controlling the population. This fish is known to contain the enzyme Phospholipase A2 (PLA2), which used as an antibiotic against some bacteria. This study will examine the antibacterial activity of the phospholipase A2 enzyme extracted from P. volitans venom to Escherichia coli, Bacillus subtilis, and Staphylococcus aureus. The method used to isolate the enzyme PLA2 is by using precipitation of ammonium sulfate (AS) and precipitation with ethanol. The results of the precipitation tested with the Lowry protein concentration test, the Marinetti PLA2 activity test, and the identification of the SDS-PAGE protein. The agar diffusion disc method is used to test the antibacterial activity. The results obtained from this research are that 80% ammonium sulfate precipitation method has the highest protein and enzyme activity with a ratio of 1.32 times compared to toxic extract. For antibacterial activity test results, an 80% ammonium sulfate sample may inhibit the activity of S. aureus bacteria but does not affect B. subtilis and E. coli.

Isolation of Kaempferol 3-O-Rutinoside from Kurdish Plant Anchusa Italica Retz. and Bioactivity of Some Extracts

Anchusa italica Retz. is naturally grown in Iraqi Kurdistan Region, and it belongs to the Boraginaceae family. From a phytochemical point of view, the species A. italica has been almost neglected so far but it is worth studying. In this study, the flavonoids were extracted from aerial parts of the plant using ethyl acetate, amyl alcohol, and n-butanol after defatting the plant by n-hexane and removing the pigments by chloroform. The residue obtained from evaporation of ethyl acetate extract was separated by reversed phase Medium Performance Liquid Chromatography (MPLC) to give a polar flavonoid. Standard UV experiments allowed for the identification of the aglycone moiety substituted pattern, while the sugar components and the interglycoside linkage was identified by different NMR spectra. The compound was eventually identified as kaempferol 3-O-rutinoside. The other aim of this investigation is to study the antimicrobial activity for some extracts of the plant. It consists of two parts; the first part was antibacterial activity using four different bacteria (E. coli, Staph. aureus, Bacillus sp. and Pseudo. aeruginosa) via agar diffusion disc method, while the second part includes antifungal activity using two different fungi (Pencillium puberulum and Aspergillus flavus). This study showed that Anchusa italica is a good antibacterial plant especially aqueous and ethanolic extracts, at which the inhibition zone reaches (13 mm), while the aqueous extract was more effective compared with the ethanol extract for antifungal.

The fabrications and characterizations of antibacterial PVA/Cu nanofibers composite membranes by synthesis of Cu nanoparticles from solution reduction, nanofibers reduction and immersion methods

In this novel innovative report, the antibacterial PVA/Cu nanofibers membranes were successfully fabricated by synthesizing and loading the Cu nanoparticles in nanofibers reduction, solution reduction, and immersion methods. The morphology of the resultant antibacterial membranes was investigated by scan electron microscopy and transmission electron microscopy. The chemical interaction was investigated by FT-IR, XPS, and EDS. The hydrophilicity of antibacterial test was investigated by water contact angle and the release behavior of Cu nanoparticles from PVA/Cu nanofibers membranes was investigated by inductively coupled plasma (ICP) study. Stress-strain behavior was studied by tensile strength test and antibacterial activity was done by Agar diffusion disc method. The resultant antibacterial membranes showed appreciable results in all characterizations. It was concluded that PVA/Cu nanofibers membranes having great potential for antibacterial properties but the membranes in which Cu nanoparticles were loaded by immersion method have highest potential than other nanofiber reduction and solution reduction methods because these PVA/Cu nanofibers membranes have 17 and 15 inhibition zone against Gram-negative Escherichia coli and Gram-positive Staphylococcus aurous bacteria which is near to Rifampicin (+ve standard) 26 and 24, respectively.

ACTIVITY OF POLYHERBAL EXTRACT AGAINST BACTERIA CAUSING SKIN INFECTIONS IN DIABETIC PATIENTS.

Objective : - The objective of this study is to evaluate antibacterial activity of Polyherbal extract on few microorganisms causing skin infections in most of the diabetic patients .Methods : - Methanolic Polyherbal extract was prepared from Acacia ferruginia (bark & fruit), Chloroxylon swietenia (bark, leaf, root), Casearia elliptica (bark), Terminalia alata (root, leaf). The preliminary phytochemical analysis was performed to identify the major phytoconstituents in the extract. Polyherbal extract was evaluated for antibacterial activity against bacteria like Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli, Proteus species, Klebsiella species causing skin infections , diabetic foot infections in diabetic patients. In-vitro method of agar diffusion disc method was used for the evaluation of antibacterial activity through zone of inhibition. The standard drug used was Gentamicin. Minimum Inhibitory Concentration (MIC) of the extract was done using broth dilution method.Results: The polyherbal extract showed good antibacterial activity. The standard drug used was Gentamicin. The Methanolic Polyherbal extract showed potent activityon all the selected microorganisms. The Polyherbal extract was active against Pseudomonas aeruginosa (2.57 + 0.39) and E.coli (2.92 + 0.29) when compared with standard. The polyherbal extract showed potent activity on Bacillus subtilis and Proteus vulgaris.Conclusion : The polyherbal extract showed broad spectrum activity by being active against gram positive and gram negative microorganisms providing the scope for further analysis as a antibacterial preparation for the skin infections in diabetes patients. Keywords: Antibacterial activity, skin infections, diabetes, Polyherbal Extract, Agar diffusion disc.

Synthesis, Characterization and Antibacterial Activity of a Tridentate Schiff Base Derived from Cephalexin and 1,6-Hexanediamine and its Transition Metal Complexes

Background: The wide use of the antibiotics resulted in the serious medical problem of drugs resistance and public health concern. Preparation of new synthetic derivatives of antibiotics with novel mechanism of action has become an important task to cope with drug resistanceproblems. Objectives: The goal of the present study is to prepare a family of new metal(II) coordination compounds of Mn, Co, Ni, Cu and Zn with a Schiff base (HL) derived from the condensation of cephalexin antibiotic with 1,6-hexanediamine and to investigate the antibacterial activity of the free cephalexin and the synthesized complexes against gram positive and gram negative strains. Methods: Several physicochemical and spectroscopic methods including elemental and thermal analysis, molar conductance and magnetic susceptibility measurements, electronic, FT-IR, EPR and 1H NMR spectral and modelling studies, were used to find out the stoichiometry and binding mode of these complexes. Free cephalexin and cephalexin Schiff base complexes have been screened for antibacterial activity by agar diffusion disc method. Results: The Schiff base ligand HL behaves as a monoanionic tridentate NNO chelating agent. The mode of bonding and the geometry of the coordination compounds have been confirmed on the basis of spectral and magnetic data which suggested an octahedral geometry for all the complexes. Based on these studies, the general formulae [M(L)(H2O)3][PF6] are proposed for the complexes. The characterization methods revealed that the investigated cephalexin exhibited modification in both solubility and antibacterial activity when they interacted with the metal ions under study. The solubility of cephalexin was remarkably decreased in most of the commonly used solvents on its complexation. The antibacterial activity results indicate that while some of the complexes had more bactericidal activity against some bacteria than the free cephalexin, other complexes exhibited less antibacterial activity. Conclusions: The antibacterial activity of cephalexin was affected on complexation with metal ions. It was found that the synthesized novel metal complexes are more toxic than the free cephalexin and exhibited promising bactericidal activity against E. coli, S. aureus and K. pneumonia.

Tetradentate metal complexes derived from cephalexin and 2,6-diacetylpyridine bis(hydrazone): Synthesis, characterization and antibacterial activity

Metal(II) coordination compounds of a hydrazone ligand (HL) derived from the condensation of cephalexin antibiotic with 2,6-diacetylpyridine bis(hydrazone) were synthesized. The hydrazone ligand and mononuclear [ML(H2O)2][PF6] (M(II)=Mn, Co, Ni, Zn) complexes were characterized by several techniques, including elemental and thermal analysis, molar conductance and magnetic susceptibility measurements, electronic, FT-IR, EPR and 1H NMR spectral studies. The cephalexin 2,6-diacetylpyridine bis(hydrazone) ligand HL behaves as a monoanionic tetradentate NNNO chelating agent. The biological applications of complexes have been studied on two bacteria strains (Escherichia coli and Staphylococcus aureus) by agar diffusion disc method.

Tridentate hydrazone metal complexes derived from cephalexin and 2-hydrazinopyridine: Synthesis, characterization and antibacterial activity

Metal(II) coordination compounds of a tridentate hydrazone ligand (HL) derived from the condensation of cephalexin antibiotic with 2-hydrazinopyridine were synthesized. The hydrazone ligand and mononuclear [ML(OAc)(H2O)] (M(II)=Mn, Co, Ni, Cu, Zn, Ag) complexes were characterized by several techniques, including elemental and thermal analysis, molar conductance and magnetic susceptibility measurements, electronic, FT-IR, EPR and 1H NMR spectral studies. The cephalexin 2-pyridinylhydrazone ligand HL behaves as a monoanionic tridentate NNO chelating agent. The biological applications of complexes have been studied on three bacteria strains (Escherichia coli, Acinetobacter baumannii and Enterococcus faecalis) by agar diffusion disc method.

Synthesis, characterization and antibacterial activity of a tridentate Schiff base derived from cephalothin and sulfadiazine, and its transition metal complexes

Metal(II) coordination compounds of a cephalothin Schiff base (H2L) derived from the condensation of cephalothin antibiotic with sulfadiazine were synthesized. The Schiff base ligand, mononuclear [ML(H2O)3] (M(II)=Mn,Co,Ni,Zn) complexes and magnetically diluted dinuclear copper(II) complex [CuL(H2O)3]2 were characterized by several techniques, including elemental and thermal analysis, molar conductance and magnetic susceptibility measurements, electronic, FT-IR, EPR and 1H NMR spectral studies. The cephalothin Schiff base ligand H2L behaves as a dianionic tridentate NOO chelating agent. The biological applications of complexes have been studied on two bacteria strains (Escherichia coli and Staphylococcus aureus) by agar diffusion disc method.

SYNTHESIS, CHARACTERISATION AND BIOLOGICAL STUDIES OF [M(CIN)2(N2H4)2] (M=NI/CD)

Ni (II) and Cd (II) complexes containing hydrazine as ligand and cinnamic acid as co-ligand were synthesized and characterized by hydrazine and metal analyses, thermal analysis and FT-IR spectral studies. It has been found that hydrazine behaves as bidentate ligand and cinnamate as monodentate ligand in the complexes. The biological activities of complexes have been evaluated against two gram negative (Escherichia coli and Pseudomonas aeruginosa) and two gram positive (Bacillus subtilis and Staphylococcus aureus) bacteria by Agar diffusion disc method. It has been found that the complexes have potent activity against the bacteria.

Antibacterial activity of crude ethanolic extract and solvent fractions of Ficus pseudopalma Blanco leaves

ObjectiveTo investigate the antimicrobial properties of Ficus pseudopalma (F. pseudopalma) leaf extracts. MethodsThe antibacterial properties of F. pseudopalma Blanco crude ethanolic leaf extract, and its solvent fractions chloroform (CF), ethylacetate (EF) and water fractions were evaluated through antibacterial agar disc diffusion method and the minimum inhibitory concentration (MIC) was determined. Five Gram-positive and five Gram-negative bacteria were used for the study. ResultsThe zone of inhibitions obtained from the antibacterial agar diffusion disc method showed that CF, and EF exhibited active (14-19 mm) antibacterial activity against Bacillus subtilis UST CMS 1011, and partially active (10-13 mm) antibacterial properties against both Staphylococcus aureus ATCC 25923 and Staphylococcus epidermidis ATCC 12228. Water exhibited no antibacterial properties against all microorgranisms tested. The MIC values observed for all Gram-positive bacteria tested were >5 mg/mL, except for Bacillus subtilis whose MIC value was 5 mg/mL for CF and EF fractions. All extracts exhibited no antibacterial activity against Gram-negative bacteria. ConclusionsFrom this study, it can be concluded that F. pseudopalma extracts may be a potential antibacterial agent against Gram-positive bacteria. The antibacterial property may be attributed to flavonoids and terpenoids present in the crude ethanolic extract, CF and EF.

Application of Nanometal Oxides In Situ in Nonwoven Polyester Fabric for the Removal of Bacterial Indicators of Pollution from Wastewater

The objective of this study is to investigate and assess the use of in situ deposit nanosilver (nAg2O) or nanocopper oxides (nCuO) into nonwoven polyester fabric (NWPF) as a safe and effective antibacterial filter of pollution from domestic wastewater. The bactericidal effect of both nAg2O and nCuO was examined against Gram-negative bacteria (Escherichia coli, Salmonella typhi) and Gram-positive bacteria (Enterococcus faecalis, Staphylococcus aureus) using agar diffusion disk method. In addition, the capability of nAg2O and nCuO as disinfectants for secondary treated domestic wastewater was investigated as a case study. Transmission electron microscope (TEM) confirmed the formation of nAg2O and nCuO particles with average particle sizes of 15 and 41 nm, respectively. Disk diffusion results showed that nAg2O had a higher bactericidal effect than nCuO. Moreover, the disinfection of secondary treated wastewater using 1.27 mg/cm3 of nAg2O in the nonwoven fabric was capable of hindering 99.6% and 91.7% of total and fecal coliforms within 10 minutes with a residual value of 18 and 15 MPN-index/100 mL, respectively. The residual total and fecal coliform concentrations were far less than that stated in the national and international limits for wastewater reuse in agriculture purpose.

Synthesis, characterization and comparative study the antibacterial activities of some imine-amoxicillin derivatives

In this study, we report the synthesis of some new Schiff base compounds (1-5) from the reaction of amoxicillin with some aromatic aldehydes in classical Schiff base method. These derivatives were characterized by melting point, elemental analysis, FT-IR and 1 H NMR data. All the synthesized compounds were evaluated in vitro for their antibacterial activities against two Gram positive ( Staphylococcus aureus, Streptococcus faecalis ) and two Gram negative ( Escherichia coli, Pseudomonas aeruginosa ) microorganisms in different concentrations (10 -1 , 10 -3 , 10 -5 and 10 -7 M) by agar diffusion disk method. The results showed that some of these derivatives have good antibacterial activities compared to biological activity of parent drug.

Screening for antimicrobial activity of thirty-three medicinal plants used in the traditional system of medicine in Pakistan

Ninety-nine aqueous, ethanolic and n-hexane extracts of thirty three medicinal plants from twenty six families used in the unani system of medicines in Pakistan were tested against ten commonly prevalent gram negative and gram positive bacteria’s particularly the enteric pathogens and yeast using agar diffusion disc method for their antimicrobial activity. Aqueous, ethanolic and n-hexane extracts of fifteen medicinal plants have no activity while other 18 plants have moderate to good antimicrobial activity. The aqueous and alcoholic extract of Adhatoda vasica Nees, Allium sativum Linn., Embelia ribes Burm. f. Mallotus phillippensis Muell., Picrorrhiza kurrooa Royle ex Benth., Ricinus communis Linn.,Elaeagnus hortensis M. Bieb., Swertia chirata Buch. Ham. and exhibited good activity against all or most of the microorganisms. The alcoholic extracts of Solanum nigrum Linn,Centella asiatica Linn, Solanum xanthocarpum Schrad and Wendl., Oxtostagia limbataBenth., Cassia angustifolia Vahl, Polygonum viviparum Linn. have moderate activity against some of the microbial strains. Antibacterial activity of some of the plant extracts can be compared with some antibiotics. This shows that Pakistan has a rich flora, having good potential of antimicrobial agents which can be used as a substitute of antibiotics and need for investigation of unexplored flora and screening for new antimicrobial agents. Key words: Antimicrobial properties, crude extracts, Pakistani medicinal plants.

Screening of the odour-activity and bioactivity of the essential oils of leaves and flowers of Hyptis Passerina Mart. from the Brazilian Cerrado

The chemical profile of the essential oils obtained from the leaves and flowers of Hyptis passerina Mart., a rare species of the Brazilian Cerrado, has been determined for the first time. Analyses by GC-MS showed sesquiterpenes as major compounds. β-epi-acorenol (35.7% and 32.8%, respectively from leaf and flower essential oils), was isolated and identified by 1D and 2D NMR. The flower-derived oil presented a higher concentration of hydrocarbon and oxygenated monoterpenes, while the leaf-oil was richer in diterpenes. The global odour impressions of both oils were given by direct analysis and GC-MS-O and were characterized as herbaceous with tea notes, and green, cooked and woody impressions for leaf-oil; herbaceous, with spicy, woody and minty notes for flower-oil. β-epi-acorenol, spathulenol, β-caryophyllene, and caryophyllene oxide were relevant for the odour-activity of both oils, as well as minor constituents, such as linalool. The antimicrobial activity was investigated by means of agar diffusion disc method and contact bioautography, against Gram-positive and negative bacteria and yeast. Both oils presented to be bioactive against the tested microorganisms with significant inhibition level.

Antimicrobial activity of Santolina chamaecyparissus L. volatile oil

In continuation of our phytochemical investigations of the Algerian flora [1,2], we studied Santolina chamaecyparissus L. a common species in the North regions of Algeria and Tunisia [3]. The aim of this study was to investigate the chemical composition of the essential oil of Santolina chamaecyparissus from Algeria and to evaluate its potential antimicrobial activity using the agar diffusion disc method against the following Gram-negative bacteria Pseudomonas aeruginosa (ATCC 9027), Escherichia coli (ATCC 4157), Klebsiella pneumonia (ATCC 4352), well as Gram-positive bacteria Staphylococcus aureus (ATCC 6538), Staphylococcus epidermis (ATCC 1228) and the fungi Candida albicans (ATCC 2601) [4]. The identification has been carried out by GC and GC-MS. The essential oil consisted of a complex mixture of 36 different substances, among them camphor (31.1%) and cubenol (17.0%) were the main compounds. The shapes of the kinetic curves of essential oil's extraction suggest that the essential oil is localized in endogenous and exogenous sites. The essential oil tested showed greater antibacterial and antifungal activities than positive controls.

Multicenter Evaluation of a New Disk Agar Diffusion Method for Susceptibility Testing of Filamentous Fungi with Voriconazole, Posaconazole, Itraconazole, Amphotericin B, and Caspofungin

The purpose of this study was to correlate inhibition zone diameters, in millimeters (agar diffusion disk method), with the broth dilution MICs or minimum effective concentrations (MECs) (CLSI M38-A method) of five antifungal agents to identify optimal testing guidelines for disk mold testing. The following disk diffusion testing parameters were evaluated for 555 isolates of the molds Absidia corymbifera, Aspergillus sp. (five species), Alternaria sp., Bipolaris spicifera, Fusarium sp. (three species), Mucor sp. (two species), Paecilomyces lilacinus, Rhizopus sp. (two species), and Scedosporium sp. (two species): (i) two media (supplemented Mueller-Hinton agar [2% dextrose and 0.5 microg/ml methylene blue] and plain Mueller-Hinton [MH] agar), (ii) three incubation times (16 to 24, 48, and 72 h), and (iii) seven disks (amphotericin B and itraconazole 10-microg disks, voriconazole 1- and 10-microg disks, two sources of caspofungin 5-microg disks [BBL and Oxoid], and posaconazole 5-microg disks). MH agar supported better growth of all of the species tested (24 to 48 h). The reproducibility of zone diameters and their correlation with either MICs or MECs (caspofungin) were superior on MH agar (91 to 100% versus 82 to 100%; R, 0.71 to 0.93 versus 0.53 to 0.96 for four of the five agents). Based on these results, the optimal testing conditions for mold disk diffusion testing were (i) plain MH agar; (ii) incubation times of 16 to 24 h (zygomycetes), 24 h (Aspergillus fumigatus, A. flavus, and A. niger), and 48 h (other species); and (iii) the posaconazole 5-microg disk, voriconazole 1-microg disk, itraconazole 10-microg disk (for all except zygomycetes), BBL caspofungin 5-microg disk, and amphotericin B 10-microg (zygomycetes only).

Multilaboratory Evaluation of an Agar Diffusion Disk Susceptibility Test for Rapidly Growing Anaerobic Bacteria

A multilaboratory collaborative study was undertaken to determine whether the anaerobic disk diffusion test of Horn et al. could be performed reproducibly and accurately. Tests with nine different antimicrobial disks were evaluated. Reproducibility of the agar diffusion disk method was similar to that of the reference agar dilution test procedure. The anaerobic disk diffusion procedure was found to be a potentially useful method for testing some antimicrobial agents against rapidly growing anaerobes belonging to the Bacteroides fragilis group. These promising results warrant further investigations and validations.