scholarly journals Evaluation of antibacterial and anti-biofilm properties of kojic acid against five food-related bacteria and related subcellular mechanisms of bacterial inactivation

2018 ◽  
Vol 25 (1) ◽  
pp. 3-15 ◽  
Author(s):  
Yu Wu ◽  
Yu-gang Shi ◽  
Lu-yao Zeng ◽  
Ying Pan ◽  
Xin-ying Huang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Minimum Inhibitory Concentration ◽  
Zeta Potential ◽  
Inhibitory Concentration ◽  
Minimum Bactericidal Concentration ◽  
Kojic Acid ◽  
Gram Negative Bacteria ◽  
Bacterial Inactivation ◽  
Intracellular Enzyme ◽  
Gram Negative

Although the antimicrobial properties of kojic acid have been recognized, the subcellular mechanism of bacterial inactivation caused by it has never been clearly elucidated. In the present study, the antibacterial and anti-biofilm activity of kojic acid was evaluated against five foodborne pathogens including Listeria monocytogenes, Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Salmonella typhimurium. The antibacterial activity was determined by minimum inhibitory concentration, minimum bactericidal concentration, and the time-kill assay. Among them, the susceptibility of Escherichia coli was significant with the lowest minimum inhibitory concentration and minimum bactericidal concentration values of 10 and 20 mM, respectively. Subcellular mechanism of bacterial inactivation related to kojic acid was revealed through comprehensive factors including cell morphology, membrane permeability, K+ leakage, zeta potential, intracellular enzyme, and DNA assay. Results demonstrated that bacterial inactivation caused by kojic acid, especially for Gram-negative bacteria, was primarily induced by the pronounced damage to the cell membrane integrity. Leakage of intracellular enzyme to the supernatants implied that the cell membrane permeability was compromised. Consequently, the release of K+ from the cytosol leads to the alterations of the zeta potential of cells, which would disturb the subcellular localization of some proteins and thereby cause the bacterial inactivation. The free −CH2OH group at the C-2 of kojic acid could play more significant role in the antimicrobial performance of kojic acid against Gram-negative bacteria. Moreover, remarkable interaction with DNA was also observed. Kojic acid at sub-minimum inhibitory concentration inhibited biofilm formation by these bacteria.

Minimum Inhibitory Concentration (MIC) versus Minimum Biofilm Eliminating Concentration (MBEC) in Evaluation of Antibiotic Sensitivity of Gram-negative Bacilli Causing Peritonitis

2004 ◽  
Vol 24 (1) ◽  
pp. 65-67 ◽  
Author(s):  
Farshad Sepandj ◽  
Howard Ceri ◽  
Allan Gibb ◽  
Ronald Read ◽  
Merle Olson
Keyword(s):  
Escherichia Coli ◽  
Peritoneal Dialysis ◽  
Minimum Inhibitory Concentration ◽  
Antibiotic Susceptibility ◽  
Inhibitory Concentration ◽  
Antibiotic Sensitivity ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Planktonic State

Objective Minimum inhibitory concentration (MIC) and minimum biofilm eliminating concentration (MBEC) results were compared to determine changes in the pattern of antibiotic sensitivity of gram-negative bacilli from the planktonic to the biofilm phase of growth. Methodology The MIC and MBEC assays were conducted on stored isolates obtained from patients presenting with peritoneal dialysis-related gram-negative peritonitis with Escherichia coli or Pseudomonas. Results The antibiotic sensitivities of planktonic organisms tested by the MIC assays were significantly higher than the antibiotic sensitivities of the same organisms in their biofilm state, as tested by the MBEC assays. Conclusions In their biofilm state, gram-negative bacteria are much less susceptible to antibiotics compared to their antibiotic susceptibility in the planktonic state.

Antimicrobial and cytotoxic activity of Macrophomina phaseolina isolated from gummosis infected citrus reticulata

2013 ◽  
pp. 125-133
Author(s):  
Rubal C Das ◽  
Rajib Banik ◽  
Robiul Hasan Bhuiyan ◽  
Md Golam Kabir
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Brine Shrimp ◽  
Inhibitory Concentration ◽  
Lethal Dose ◽  
Macrophomina Phaseolina ◽  
Chloroform Extract ◽  
Citrus Reticulata ◽  
Gram Negative Bacteria ◽  
Gram Negative

Macrophomina phaseolina is one of the pathogenic organisms of gummosis disease of orange tree (Citrus reticulata). The pathogen was identified from the observation of their colony size, shape, colour, mycelium, conidiophore, conidia, hyaline, spore, and appressoria in the PDA culture. The crude chloroform extracts from the organism showed antibacterial activity against a number of Gram positive and Gram-negative bacteria. The crude chloroform extract also showed promising antifungal activity against three species of the genus Aspergillus. The minimum inhibitory concentration (MIC) of the crude chloroform extract from M. phaseolina against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Shigella sonnie were 128 ?gm, 256 ?gm, 128 ?gm and 64 ?gm/ml respectively. The LD50 (lethal dose) values of the cytotoxicity assay over brine shrimp of the crude chloroform extract from M. phaseolina was found to be 51.79 ?gm/ml. DOI: http://dx.doi.org/10.3329/cujbs.v5i1.13378 The Chittagong Univ. J. B. Sci.,Vol. 5(1 &2):125-133, 2010

Serum Inhibitory and Bactericidal Activity of Ciprofloxacin following Intravenous Administration

DICP ◽  
1989 ◽  
Vol 23 (6) ◽  
pp. 456-460
Author(s):  
Michael N. Dudley ◽  
Hilary D. Mandler ◽  
Kenneth H. Mayer ◽  
Stephen H. Zinner
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Minimum Inhibitory Concentration ◽  
Bactericidal Activity ◽  
Resistant Strain ◽  
Inhibitory Concentration ◽  
Minimum Bactericidal Concentration ◽  
E Coli ◽  
Dose Levels

Serum inhibitory and bactericidal titers were measured in nine healthy volunteers following single iv doses of ciprofloxacin 100, 150, and 200 mg. The median peak serum bactericidal titer (5 minutes following completion of a 30-minute infusion) against two highly susceptible strains of Escherichia coli ranged between 1:64 and 1:1024 and titers exceeded 1:8 for six hours for all dose levels. The bactericidal titers against two strains of Pseudomonas aeruginosa and a methicillin-resistant strain of Staphylococcus aureus were considerably lower, the median peak being 1:2 at all dose levels. Measured inhibitory and bactericidal titers at five minutes and one hour postinfusion were significantly greater than those predicted (measured serum ciprofloxacin concentration to minimum inhibitory concentration [MIC] or minimum bactericidal concentration [MBC]) for only one strain of E. coli. Intravenous doses of ciprofloxacin 100–200 mg produce high and sustained serum bactericidal titers against highly susceptible bacteria; considerably lower levels of activity are seen against bacteria having higher MICs and MBCs but still considered susceptible to the drug.

scholarly journals 5-Bromo-1-(4-chlorobenzyl)-1H-indole-2-carboxamides as new potent antibacterial agents

2018 ◽  
Vol 24 (6) ◽  
pp. 327-332 ◽  
Author(s):  
Yogesh D. Mane ◽  
Smita S. Patil ◽  
Dhanraj O. Biradar ◽  
Bhimrao C. Khade
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Antibacterial Agents ◽  
Inhibitory Concentration ◽  
Antibacterial Activities ◽  
Gram Negative Bacteria ◽  
Internal Standards ◽  
Gram Negative ◽  
E Coli ◽  
High Antibacterial Activity

Abstract Ten 5-bromoindole-2-carboxamides were synthesized, characterized and evaluated for antibacterial activity against pathogenic Gram-negative bacteria Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa and Salmonella Typhi using gentamicin and ciprofloxacin as internal standards. Compounds 7a–c, 7g and 7h exhibit high antibacterial activity with a minimum inhibitory concentration (MIC) of 0.35–1.25 μg/mL. Compounds 7a–c exhibit antibacterial activities that are higher than those of the standards against E. coli and P. aeruginosa.

scholarly journals Colistin-resistant Escherichia coli clinical isolate harbouring the mcr-1 gene in Ecuador

2016 ◽  
Vol 144 (14) ◽  
pp. 2967-2970 ◽  
Author(s):  
D. ORTEGA-PAREDES ◽  
P. BARBA ◽  
J. ZURITA
Keyword(s):  
Escherichia Coli ◽  
Minimum Inhibitory Concentration ◽  
Clinical Isolate ◽  
Inhibitory Concentration ◽  
Resistance Mechanism ◽  
Sequence Type ◽  
Colistin Resistance ◽  
Gram Negative ◽  
E Coli ◽  
Commensal Strain

SUMMARYColistin resistance mediated by the mcr-1 gene has been reported worldwide, but to date not from the Andean region, South America. We report the first clinical isolate of Escherichia coli harbouring the mcr-1 gene in Ecuador. The strain was isolated from peritoneal fluid from a 14-year-old male with acute appendicitis, and subjected to molecular analysis. The minimum inhibitory concentration of colistin for the strain was 8 mg/ml and it was susceptible to carbapenems but resistant to tigecycline. The strain harboured mcr-1 and blaCTX-M-55 genes and was of sequence type 609. The recognition of an apparently commensal strain of E. coli harbouring mcr-1 serves as an alert to the presence in the region of this recently described resistance mechanism to one of the last line of drugs available for the treatment of multi-resistant Gram-negative infections.

scholarly journals Antibacterial Activity of Murrayaquinone A and 6-Methoxy-3,7-dimethyl-2,3-dihydro-1H-carbazole-1,4(9H)-dione

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Biswanath Chakraborty ◽  
Suchandra Chakraborty ◽  
Chandan Saha
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Bacillus Subtilis ◽  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Antibacterial Activities ◽  
Gram Positive ◽  
Gram Negative ◽  
Naturally Occurring

The antibacterial activity of Murrayaquinone A (10), a naturally occurring carbazoloquinone alkaloid, and 6-methoxy-3,7-dimethyl-2,3-dihydro-1H-carbazole-1,4(9H)-dione (11), a synthetic carbazoloquinone, both obtained during the development of the synthesis of Carbazomycin G, having unique quinone moiety, was studied against Gram-positive (Bacillus subtilisandStaphylococcus aureus) and Gram-negative (Escherichia coliandPseudomonassp.) bacteria. Compound10showed antibacterial activities against both ofEscherichia coliandStaphylococcus aureuswhereas compound11indicated the activity againstStaphylococcus aureusonly. Both compounds10and11exhibited minimum inhibitory concentration (MIC) of 50 μg mL−1againstStaphylococcus aureus.

scholarly journals Minimum Inhibitory Concentration (MIC) Of Liquid Smoke Produced from Piper Betle L Against Salmonella sp and Staphylococcus aureus

2020 ◽  
Vol 11 (1) ◽  
pp. 89-98
Author(s):  
Dodi Irwandi ◽  
Ai Emalia Sukmawati
Keyword(s):  
Staphylococcus Aureus ◽  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Piper Betle ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Betel Leaf ◽  
Liquid Smoke ◽  
Grade 3 ◽  
And Staphylococcus Aureus

The betel (Piper betle L) is an herb that has one of the properties, namely as an antibacterial. Several studies have shown green betel leaf extract can inhibit the growth of Gram-positive and Gram negative bacteria. In this study, the antibacterial activity of liquid smoke produced from betel leaf by pyrolysis using a simple pyrolysis reactor was tested. Tests are carried out on 2 types of liquid smoke namely grade 3 which is the first product of the pyrolysis process and grade 2 which is the result of distillation from grade 3. Both types of liquid smoke are prepared into concentration of 100%, 75%, 50%, 25% respectively water as a solvent. Two types of bacteria are used, namely Salmonella sp as Gram-negative bacteria and Staphylococcus aureus as Gram-positive. The test results show that grade 3 and grade 2 liquid smoke give minimum inhibitory concentration (MIC) at the same concentration of 50% against Salmonella sp and, Staphylococcus aureus at 25%, 75% concentrations, respectively.

Synthesis, properties and photodynamic activities of some zinc(II) phthalocyanines against Escherichia coli and Staphylococcus aureus

2008 ◽  
Vol 12 (08) ◽  
pp. 953-963 ◽  
Author(s):  
Ozlem Seven ◽  
Bircan Dindar ◽  
Sohret Aydemir ◽  
Feriha Cilli
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Photodynamic Therapy ◽  
Singlet Oxygen ◽  
Gram Negative Bacteria ◽  
Bacterial Inactivation ◽  
Gram Negative ◽  
Oxygen Generation ◽  
Gram Positive Bacteria ◽  
Singlet Oxygen Generation

Two new zinc phthalocyanine derivatives bearing four 3,5-di-tert-butyl-4-hydroxyphenyl (ZnPc1) and 3,5-dimethylphenoxy (ZnPc2) have been synthesized and proved by elemental analyses and UV-vis, 1H NMR, FTIR and MALDI-TOF mass spectra as spectroscopic determination. Thermal stabilities of these neutral Zn -phthalocyanines were performed by thermal gravimetric analysis and, significantly, were found stable up to 373 °C for ZnPc1 and 550 °C for ZnPc2. In addition, the photostability of the sensitizers was quite successful within 240 min. Furthermore, photodynamic therapy has been investigated using these neutral phthalocyanines. Singlet oxygen generation capacities of ZnPc1 and ZnPc2 were studied using 1,3-diphenyl-iso-benzofuran (50.0 μM) as a selective singlet oxygen trap in DMSO and both of them demonstrated very high singlet oxygen generation capacity. Photodynamic therapy is of considerable interest for its potential as an antimicrobial therapy on the grounds that the photodynamic activity of these compounds was tested against a Gram-negative bacteria, Escherichia coli and a Gram-positive bacteria, Staphylococcus aureus. Suspensions of the microorganisms were irradiated for 240 min in the presence of ZnPc1 (with hydrophilic group) and ZnPc2 phthalocyanines. In order to simulate solar radiation, we used a 750 W xenon lamp. Minimum photosensitizer concentration was used as 0.1 mg.10 mL-1 in 1% dimethylsulfoxide/phosphate buffer saline solution (DMSO/PBS). Moreover, the photostability of these compounds has been investigated and the effect of the amount of DMSO tested against selected bacteria. In the dark, with and without Pcs, bacterial inactivation did not occur. Bacterial inactivation by light with ZnPc1 was observed in response to Gram-negative bacteria E. coli and Gram-positive bacteria S. aureus, whereas the photoinactivation studies with ZnPc2 have revealed that the lack of its activity is due to its poor affinity for either of the organisms. These results suggest that a neutral amphiphilic photosensitizer may be easily used in an application concerning photoinactivation of bacterial cells as well as ionic photosensitizers.

scholarly journals Evaluation of the Antimicrobial Activity of Buriti (Mauritia Flexuosa) Pulp Extracts

2019 ◽  
Vol 11 (1) ◽  
pp. 89-94
Author(s):  
Carla Roana Moraes Monteiro ◽  
Adriele Rodrigues dos Santos ◽  
Marcos Vieira da Silva ◽  
Adenilson Renato Rudke ◽  
Iara de Melo Rodrigues ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Inhibitory Concentration ◽  
Minimum Bactericidal Concentration ◽  
Palm Tree ◽  
Gram Negative ◽  
Mauritia Flexuosa ◽  
Pharmaceutical Industries ◽  
Positive Results

Background: Buriti (Mauritia flexuosa) is a palm tree typical of the Amazon region. This plant belongs to the Arecaceae family and is economically important because it contains substances important for the food, cosmetic and pharmaceutical industries. It has, in its fruits, compounds with antimicrobial potential. Objective: The objective of this study was to evaluate the minimal inhibitory concentration and minimum bactericidal concentration of the Buriti extracts against the four bacteria: Salmonella enterica serotype Typhimurium ATCC 14028, Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853. Methods: 15 extracts from buriti pulp were obtained varying in temperature, mass of buriti and ethanol content. The antimicrobial activity of these extracts was evaluated. To determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), the methodology recommended by the Clinical and Laboratory Standards Institute was followed. Results: The results showed which buriti pulp extracts had strong inhibitory activity. Gram-positive results ranged from 21 to 78 μg.mL-1. For Gram-negative, they ranged from 30 to 111 μg.mL-1. Conclusion: The buriti extracts significantly slowed the growth of the tested bacteria.

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