In Vitro Antibacterial Susceptibility of Different Pathogens to Thirty Nano-Polyoxometalates

Due to their unique properties, nano-polyoxometalates (POMs) can be alternative chemotherapeutic agents instrumental in designing new antibiotics. In this research, we synthesized and characterized “smart” nanocompounds and validated their antibacterial effects in order to formulate and implement potential new drugs. We characterized thirty POMs in terms of antibacterial activity–structure relationship. The antibacterial effects of these compounds are directly dependent upon their structure and the type of bacterial strain tested. We identified three POMs that presented sound antibacterial activity against S. aureus, B. cereus, E. coli, S. enteritidis and P. aeruginosa strains. A newly synthesized compound K6[(VO)SiMo2W9O39]·11H2O (POM 7) presented antibacterial activity only against S. aureus (ATCC 6538P). Twelve POMs exerted antibacterial effects against both Gram-positive and Gram-negative strains. Only one POM (a cluster derivatized with organometallic fragments) exhibited a stronger effect compared to amoxicillin. New studies in terms of selectivity and specificity are required to clarify these extremely important aspects needed to be considered in drug design.

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Phytochemical analysis and antibacterial activity of extract from lantana camara l. leaves

10.21203/rs.3.rs-151542/v1 ◽

2021 ◽

Author(s):

Bondy Lourenço ◽

Asimbawe Kiza ◽

Abrão Amândio João ◽

Clemência Félix Odala Niconte ◽

Pompílio Armando Vintuar ◽

...

Keyword(s):

Antibacterial Activity ◽

Lantana Camara ◽

Diffusion Method ◽

Phytochemical Analysis ◽

Leaf Extracts ◽

Disk Diffusion Method ◽

E Coli ◽

Significant Difference ◽

New Antibiotics

Abstract Background: Currently, several studies are being conducted to test antibacterial activity of various medicinal plants, in attempt to develop new antibiotics or to potentiate the action of antibiotics of known clinical use. In this research, phytochemical analysis and in vitro antibacterial activity of leaf extracts of Lantana camara L were performed.Methods The extracts were obtained through maceration with 90% ethanol. In phytochemical analysis, alkaloids, flavonoids, tannins and saponins were identified using specific reagents for each class.The antibacterial activity was analyzed using the disk diffusion method according to Kirby-Bauer, against Escherichia coli and Staphylococus aureus.Key findings The diameters of the inhibition halos varied between 0.7 and 12 mm, with an average of 8.26 mm for strains of S. aureus and there was no inhibition for E. coli. The results showed a significant difference between the inhibition halos and the tested concentrations for S. aureus. In conclusion L. camara leaf extracts are rich in bioactive compounds and have a good antibacterial potential against S. aureus and not for E. coli. And there was no relationship between the concentration of the extract and the diameter of the halo of inhibition of the evaluated microorganism.

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Phytochemical Analysis and Antibacterial Activity of Extract From Lantana Camara L. Leaves

10.21203/rs.3.rs-156702/v1 ◽

2021 ◽

Author(s):

Bondy Jorge Lourenço ◽

Asimbawe Kiza ◽

ABRÃO AMÂNDIO JOÃO ◽

Clemência FÉLIX ODALA Niconte ◽

POMPÍLIO ARMANDO Vintuar ◽

...

Keyword(s):

Antibacterial Activity ◽

Lantana Camara ◽

Diffusion Method ◽

Phytochemical Analysis ◽

Leaf Extracts ◽

Disk Diffusion Method ◽

E Coli ◽

Significant Difference ◽

New Antibiotics

Abstract Background: Currently, several studies are being conducted to test antibacterial activity of various medicinal plants, in attempt to develop new antibiotics or to potentiate the action of antibiotics of known clinical use. In this research, phytochemical analysis and in vitro antibacterial activity of leaf extracts of Lantana camara L were performed.The extracts were obtained through maceration with 90% ethanol. In phytochemical analysis, alkaloids, flavonoids, tannins and saponins were identified using specific reagents for each class.The antibacterial activity was analyzed using the disk diffusion method according to Kirby-Bauer, against Escherichia coli and Staphylococus aureus. Results: The diameters of the inhibition halos varied between 0.7 and 12 mm, with an average of 8.26 mm for strains of S. aureus and there was no inhibition for E. coli. The results showed a significant difference between the inhibition halos and the tested concentrations for S. aureus. Conclusions: L. camara leaf extracts are rich in bioactive compounds and have a good antibacterial potential against S. aureus and not for E. coli. And there was no relationship between the concentration of the extract and the diameter of the halo of inhibition of the evaluated microorganism.

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Phytochemical analysis and antibacterial activity of extract from lantana camara l. leaves

10.21203/rs.3.rs-151542/v2 ◽

2021 ◽

Author(s):

Bondy Lourenço ◽

Asimbawe Kiza ◽

Abrão Amândio João ◽

Clemência Félix Odala Niconte ◽

Pompílio Armando Vintuar ◽

...

Keyword(s):

Antibacterial Activity ◽

Lantana Camara ◽

Diffusion Method ◽

Phytochemical Analysis ◽

Leaf Extracts ◽

Disk Diffusion Method ◽

E Coli ◽

Significant Difference ◽

New Antibiotics

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In Vitro Antibacterial activity of ethanolic extract of Myrsine africana against laboratory Strains of Pathogenic Organisms

International Journal of Bioassays ◽

10.21746/ijbio.2016.04.0011 ◽

2016 ◽

Vol 5 (04) ◽

pp. 4512

Author(s):

Jackie K. Obey ◽

Anthoney Swamy T* ◽

Lasiti Timothy ◽

Makani Rachel

Keyword(s):

Antibacterial Activity ◽

Minimum Inhibitory Concentration ◽

Inhibitory Concentration ◽

Ethanolic Extract ◽

Ethanol Extract ◽

E Coli ◽

Zones Of Inhibition ◽

In Vitro Antibacterial Activity ◽

Myrsine Africana

The determination of the antibacterial activity (zone of inhibition) and minimum inhibitory concentration of medicinal plants a crucial step in drug development. In this study, the antibacterial activity and minimum inhibitory concentration of the ethanol extract of Myrsine africana were determined for Escherichia coli, Bacillus cereus, Staphylococcus epidermidis and Streptococcus pneumoniae. The zones of inhibition (mm±S.E) of 500mg/ml of M. africana ethanol extract were 22.00± 0.00 for E. coli,20.33 ±0.33 for B. cereus,25.00± 0.00 for S. epidermidis and 18. 17±0.17 for S. pneumoniae. The minimum inhibitory concentration(MIC) is the minimum dose required to inhibit growth a microorganism. Upon further double dilution of the 500mg/ml of M. africana extract, MIC was obtained for each organism. The MIC for E. coli, B. cereus, S. epidermidis and S. pneumoniae were 7.81mg/ml, 7.81mg/ml, 15.63mg/ml and 15.63mg/ml respectively. Crude extracts are considered active when they inhibit microorganisms with zones of inhibition of 8mm and above. Therefore, this study has shown that the ethanol extract of M. africana can control the growth of the four organisms tested.

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Flavone-Rich Fractions and Extracts from Oroxylum indicum and Their Antibacterial Activities against Clinically Isolated Zoonotic Bacteria and Free Radical Scavenging Effects

Molecules ◽

10.3390/molecules26061773 ◽

2021 ◽

Vol 26 (6) ◽

pp. 1773

Author(s):

Patchima Sithisarn ◽

Piyanuch Rojsanga ◽

Pongtip Sithisarn

Keyword(s):

Antibacterial Activities ◽

Inhibitory Effect ◽

Total Flavonoid ◽

Total Phenolic ◽

Antibacterial Effects ◽

E Coli ◽

Young Fruit ◽

Oroxylum Indicum ◽

Zoonotic Bacteria

Oroxylum indicum extracts from the seeds collected from Lampang and Pattani provinces in Thailand, and young fruits and flowers exhibited in vitro display antioxidant and antibacterial activities against clinically isolated zoonotic bacteria including Staphylococcus intermedius, Streptococcus suis, Pseudomonas aeruginosa, β-hemolytic Escherichia coli and Staphylococcus aureus. The orange crystals and yellow precipitates were obtained from the preparation processes of the seed extracts. The orange-red crystals from the seeds collected from Lampang province exhibited strong in vitro 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging effects (EC50 value = 25.99 ± 3.30 μg/mL) and antibacterial effects on S. intermedius and β-hemolytic E. coli while the yellow precipitate from the same source exhibited only antioxidant activity. Quantitative analysis of phytochemicals in O. indicum samples by spectrophotometric and HPLC techniques showed that they contained different amounts of total phenolic, total flavonoid and three major flavones; baicalin, baicalein and chrysin contents. Young fruit extract, which contained low amounts of flavone contents, still promoted antibacterial effects against the tested bacteria with IC50 values lower than 1 mg/mL and MIC values between 4 to 10 mg/mL in S. intermedius, S. aureus and S suis while higher IC50 and MIC values against P. aeruginosa and β-hemolytic E. coli were found. From scanning electron microscopy, the extract of the young fruit of O. indicum promoted morphological changes in the bacterial cells by disrupting the bacterial cell walls, inducing leakage of the cellular content, and generating the abnormal accumulation of cells. The mechanism of action of the extract for this antibacterial effect may be the disruption of the cell membrane and abnormal cell aggregations. Regression analysis of the results suggests the correlation between total phenolic and total flavonoid contents and antioxidant and antibacterial effects. Baicalin was found to have a high correlation with an inhibitory effect against β-hemolytic E. coli while three unidentified peaks, which could be flavones, showed high correlations with an inhibitory effect against S. intermedius, S. suis, P. aeruginosa and S. aureus.

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STUDY OF ANTIBACTERIAL ACTIVITY OF THE PREPARATIONS WITH DIOXIDINE AND LEVOFLOXACIN ON MAIN PURULENT-INFLAMMATORY PROCESSES PATHOGENS

Wiadomości Lekarskie ◽

10.36740/wlek202109115 ◽

2021 ◽

Vol 74 (9) ◽

pp. 2109-2111

Author(s):

Evheniia A. Shtaniuk ◽

Oleksandra O. Vovk ◽

Larisa V. Krasnikova ◽

Yuliia I. Polyvianna ◽

Tetiana I. Kovalenko

Keyword(s):

Antibacterial Activity ◽

Water Soluble ◽

Diffusion Method ◽

E Coli ◽

Mueller Hinton ◽

Microbiological Methods ◽

Pure Cultures ◽

Inflammatory Processes ◽

Definition Of

The aim: Study of antibacterial activity of the preparations, containing antiseptic dioxidine and antibiotic levofloxacin in vitro on standard strains of main optional-anaerobic pathogens of purulent-inflammatory processes of surgical wounds S. aureus, E. coli, P. aeruginosa and definition of more effective ones on them. Materials and methods: Solutions of dioxidine 1.2 %, dioxidine 1.2% with decamethaxin, Dioxisole, water soluble ointment with dioxidine 1.2% and levofloxacin 0.1% with decamethaxin were used in experiment. Antibacterial activity was studied on standard strains of S. aureus АТСС 25923, E. coli АТСС 25922, P. aeruginosa АТСС 27853. Distinguishing and identification of pure cultures of bacteria was done according to generally accepted microbiological methods. Determination of purulent-inflammatory processes pathogens sensitivity was done by disco-diffuse method on Mueller-Hinton medium. Antibacterial activity of solutions and ointments was studied with the help of agar diffusion method (“well” method) according to methodic recommendations. Each investigation was repeated 6 times. Method of variation statistics was used for the research results analysis. Results: All antibacterial preparations under study are effective and highly effective on S. aureus АТСС 25923, E. coli АТСС 25922, P. aeruginosa АТСС 27853. Solution with 1.2 % dioxidine with decamethaxin and ointment with 0.1 % levofloxacin and decamethaxin have larger growth retardation zones towards S. aureus and P. aeruginosa. E. coli strains are more sensitive to the solution of Dioxisole and ointment with 1.2 % dioxidine. Conclusions: All strains are sensitive, most of them are highly sensitive, up to 5 antibacterial preparations under study in vitro.

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Colombian frogs: promising source of new antibiotics

10.21203/rs.2.22848/v1 ◽

2020 ◽

Author(s):

Esteban Alzate ◽

Laura Mejía ◽

Maria Clara Nuñez ◽

Julie Benavides ◽

David Galvis-Pareja ◽

...

Keyword(s):

Antibacterial Activity ◽

E Coli ◽

Microdilution Method ◽

Comparable Effect ◽

Frog Species ◽

New Antibiotics ◽

Inhibition Zones ◽

Human Use ◽

Promising Source ◽

Positive Controls

Abstract Background: In middle Magdalena of the Antioquia region, Colombia frog secretions have been used as antibacterial agents, the purpose of this study is to assess the antibacterial activity of six frog species secretions. Methods: the Kirby-Bauer and the microdilution methods were used to evaluate antibacterial activity of the frogs secretions against S. aureus and E. coli, using two positive controls, ampicillin and ciprofloxacin. Results: secretions of all six families showed inhibition zones, the concentration at which this zone was bigger was assayed later by the microdilution method and compared to ampicillin and ciprofloxacin. Only the secretion from the Phyllomedusidae exhibited a comparable effect to that one of control antibiotics. Conclusions: in here we provide evidence that secretions from local frogs have an antibacterial effect against two strains of bacteria, further studies are needed to identify the peptides in the secretions and a wider range of safe concentrations for human use.

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Investigating In Vitro Antibacterial Activities of Medicinal Plants Having Folkloric Repute in Ethiopian Traditional Medicine

Journal of Evidence-Based Integrative Medicine ◽

10.1177/2515690x19886276 ◽

2019 ◽

Vol 24 ◽

pp. 2515690X1988627 ◽

Cited By ~ 1

Author(s):

Mekonnen Sisay ◽

Negussie Bussa ◽

Tigist Gashaw ◽

Getnet Mengistu

Keyword(s):

Antibacterial Activity ◽

Medicinal Plants ◽

Antimicrobial Agents ◽

Bacterial Isolates ◽

Zone Of Inhibition ◽

Traditional Use ◽

Gram Negative ◽

E Coli ◽

Slow Development

Medicinal plants are targeted in the search for new antimicrobial agents. Nowadays, there is an alarmingly increasing antimicrobial resistance to available agents with a very slow development of new antimicrobials. It is, therefore, necessary to extensively search for new agents based on the traditional use of herbal medicines as potential source. The antibacterial activity of 80% methanol extracts of the leaves of Verbena officinalis (Vo-80ME), Myrtus communis (Mc-80ME), and Melilotus elegans (Me-80ME) was tested against 6 bacterial isolates using agar well diffusion technique. In each extract, 3 concentrations of 10, 20, and 40 mg/well were tested for each bacterium. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were also determined. Vo-80ME and Mc-80ME exhibited promising antibacterial activity against Staphylococcus aureus with the highest zone of inhibition being 18.67 and 26.16 mm, respectively at concentration of 40 mg/well. Regarding gram-negative bacteria, Vo-80ME exhibited an appreciable activity against Escherichia coli and Salmonella typhi. Mc-80ME displayed remarkable activity against all isolates including Pseudomonas aeruginosa with the maximum zone of inhibition being 22.83 mm. Me-80ME exhibited better antibacterial activity against E coli, but its secondary metabolites had little or no activity against other gram-negative isolates. The MIC values of Vo-80ME ranged from 0.16 to 4.00 mg/mL. The lowest MIC was observed in Mc-80ME, with the value being 0.032 mg/mL. Mc-80ME had bactericidal activity against all tested bacterial isolates. Mc-80ME showed remarkable zone of inhibitions in all tested bacterial isolates. Besides, Vo-80ME showed good antibacterial activity against S aureus, E coli, and S typhi. Conversely, Me-80ME has shown good activity against E coli only. Generally, M communis L and V officinalis have good MIC and MBC results.

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Fabrication & Characterization of Chitosan Coated Biologically Synthesized TiO2 Nanoparticles against PDR E. coli of Veterinary Origin

Advances in Polymer Technology ◽

10.1155/2020/8456024 ◽

2020 ◽

Vol 2020 ◽

pp. 1-13 ◽

Cited By ~ 2

Author(s):

Naheed Zafar ◽

Bushra Uzair ◽

Muhammad Bilal Khan Niazi ◽

Shamaila Sajjad ◽

Ghufrana Samin ◽

...

Keyword(s):

Electron Microscopy ◽

Antibacterial Activity ◽

Titanium Dioxide ◽

Morphological Changes ◽

Titanium Dioxide Nanoparticles ◽

Chitosan Nanoparticles ◽

Diffusion Method ◽

Potential Threat ◽

E Coli

Treatment of pandrug resistant (PDR) Escherichia coli strain is the leading causative agent of bovine mastitis worldwide. Hence, becoming a potential threat to veterinary and public health. Therefore, to control the infection new nontoxic, biocompatible antimicrobial formulation with enhanced antibacterial activity is massively required. Current study was planned to synthesize chitosan coated titanium dioxide nanoparticles (CS-NPs coated TiO2). Coating was being done by chitosan nanoparticles (CS-NPs) using ionic gelation method. Aqueous solution of Moringa concanensis leaf extract was used to synthesize titanium dioxide nanoparticles (TiO2 NPs). The synthesized nanoformulations were characterized by using XRD, SEM, and FTIR. X-ray diffraction (XRD) analysis indicated the crystalline phase of TiO2 NPs and CS-NPs coated TiO2 NPs. Scanning Electron Microscopy (SEM) confirmed spherical shaped nanoparticles size of chitosan NPs ranging from 19–25 nm and TiO2 NPs 35–50 nm. Thesize of CS-NPs coated TiO2 NPs was in the range of 65–75 nm. The UV-Vis Spectra and band gap values illustrated the red shift in CS-NPs coated TiO2 NPs. Fourier transform infrared (FTIR) spectroscopy confirmed the linkages between TiO2 NPs and chitosan biopolymer, Zeta potential confirmed the stability of CS-NPs coated TiO2 NPs by showing 95 mV peak value. In-vitro antibacterial activity of CS-NPs coated TiO2 NPs and Uncoated TiO2 NPs was evaluated by disc diffusion method against PDR strain of E. coli isolated from mastitic milk samples. The antibacterial activity of all the synthesized nanoformulations were noted and highest antibacterial activity was shown by CS-NPs coated TiO2-NPs against pandrug resistant (PDR) E. coli strain with the prominent zone of inhibition of 23 mm. Morphological changes of E. coli cells after the treatment with MIC concentration (0.78 μg/ml) of CS-NPs coated TiO2 NPs were studied by transmission electron microscopy TEM showedrigorous morphological defectand has distorted the general appearance of the E. coli cells. Cytotoxicity (HepG2 cell line) and hemolytic (human blood) studies confirmed nontoxic/biocompatible nature of CS-NPs coated biologically synthesized TiO2 NPs. The results suggested that biologically synthesized and surface modified TiO2 NPs by mucoadhesive polysaccharides (e.g. chitosan) coating would be an effective and non-toxic alternative therapeutic agent to be used in livestock industry to control drug resistant veterinary pathogens.

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Antibacterial Effects of Levofloxacin, Erythromycin, and Rifampin in a Human Monocyte System againstLegionella pneumophila

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.42.12.3153 ◽

1998 ◽

Vol 42 (12) ◽

pp. 3153-3156 ◽

Cited By ~ 33

Author(s):

Aldona L. Baltch ◽

Raymond P. Smith ◽

Mary A. Franke ◽

Phyllis B. Michelsen

Keyword(s):

Antibacterial Activity ◽

Legionella Pneumophila ◽

Human Monocyte ◽

Antibacterial Activities ◽

Human Monocytes ◽

Antibacterial Effects ◽

In Vitro System ◽

Time Period ◽

Time Periods

ABSTRACT The antibacterial activities of levofloxacin, erythromycin, and rifampin against intracellular Legionella pneumophilaL-1033, serogroup 1, were studied. In an in vitro system utilizing adherent human monocytes, L. pneumophila L-1033, a phagocytosis time period of 1 h, and antibiotic (levofloxacin, erythromycin, and/or rifampin) at 1 to 10 times the MIC, the CFU/ml values for the monocyte lysate were determined during 0- to 4-day time periods. The decrease in CFU/ml with levofloxacin at pH 7.4 was rapid, occurring within 24 h, and was drug concentration dependent (P < 0.01). The decrease in CFU with rifampin was first observed at 48 h (P < 0.01), while only a minimal decrease in CFU/ml was observed with erythromycin. Combination of levofloxacin and rifampin and of levofloxacin and erythromycin at ten times their MICs significantly decreased the CFU/ml value (P < 0.01), to the value attained by levofloxacin alone, while combination of rifampin and erythromycin did not. Removal of levofloxacin after 24 h of incubation resulted in regrowth ofL. pneumophila L-1033, while a continued slow decrease in CFU/ml was seen following rifampin removal; CFU/ml values were unaffected by the removal of erythromycin. At 4 days, and even in assays performed following antibiotic removal, the CFU/ml value continued to be lower in the levofloxacin and rifampin assays than in the assays with erythromycin. Levofloxacin had a significantly higher bactericidal activity against L. pneumophila L-1033 than erythromycin or rifampin. In these assays, the addition of erythromycin or rifampin did not affect the antibacterial activity of levofloxacin.

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