Syzygium jambosDisplayed Antibacterial and Antibiotic-Modulating Activities against Resistant Phenotypes

The present study was designed to evaluate the antibacterial activities of methanol extracts of bark and leaves ofSyzygium jambos, as well as their synergistic effects with selected antibiotics against drug-resistant Gram-positive and Gram-negative bacteria. The crude extracts were subjected to qualitative phytochemical screening; broth microdilution method was used for antibacterial assays. Phytochemical studies indicate that leaves and bark extracts contained polyphenols, anthraquinones, tannins, and steroids. Extract of the leaves was active against all the 26 strains ofStaphylococcus aureusand all the 21 strains of Gram-negative bacteria tested, within the minimum inhibitory concentration (MIC) range of 32–512 μg/mL. The lowest MIC value of 32 μg/mL was obtained with extract of the leaves againstStaphylococcus aureusMRSA9 strain. In Gram-negative bacteria, the lowest MIC value of 64 μg/mL was also obtained againstEnterobacter aerogenesEA294 andKlebsiella pneumoniaeK24 strains. AgainstS. aureusstrains, antibiotic-modulating activity of extracts at MIC/2 towards more than 70% of the tested strains was obtained when leaves and bark extracts were tested in association with chloramphenicol (CHL). This was also the case when leaves extract was combined with CHL, kanamycin (KAN), tetracycline (TET), and erythromycin (ERY) and when bark extract was combined with ciprofloxacin (CIP), TET, and ERY against Gram-negative bacteria. In conclusion, this study demonstrated thatSyzygium jamboshas antibacterial and antibiotic-modulating activities.

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Antibacterial and Cytotoxic Activities of the Sesquiterpene Lactones Cnicin and Onopordopicrin

Natural Product Communications ◽

10.1177/1934578x1100600202 ◽

2011 ◽

Vol 6 (2) ◽

pp. 1934578X1100600 ◽

Cited By ~ 5

Author(s):

Sandra M. Bach ◽

Mario A. Fortuna ◽

Rodgoun Attarian ◽

Juliana T. de Trimarco ◽

César A. N. Catalán ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Antibacterial Activity ◽

Methicillin Resistant Staphylococcus Aureus ◽

Sesquiterpene Lactones ◽

Antibacterial Activities ◽

Chloroform Extract ◽

Cytotoxic Activities ◽

Gram Negative Bacteria ◽

Gram Negative ◽

High Cytotoxicity

The antimicrobial and cytotoxic activities of chloroform extracts from the weeds Centaurea tweediei and C. diffusa, and the main sesquiterpene lactones isolated from these species, onopordopicrin and cnicin, respectively, were assayed. Results show that the chloroform extracts from both Centaurea species possess antibacterial activities against a panel of Gram-positive and Gram-negative bacteria. Remarkable antibacterial activity against methicillin-resistant Staphylococcus aureus was also measured. Both the extracts and the purified sesquiterpene lactones show high cytotoxicity against human-derived macrophages. Despite this cytotoxicity, C. diffusa chloroform extract and cnicin are attractive candidates for evaluation as antibiotics in topical preparations against skin-associated pathogens.

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Oxidative Stress and Antimicrobial Activity of Chromium(III) and Ruthenium(II) Complexes onStaphylococcus aureusandEscherichia coli

BioMed Research International ◽

10.1155/2013/906912 ◽

2013 ◽

Vol 2013 ◽

pp. 1-7 ◽

Cited By ~ 13

Author(s):

Paulina L. Páez ◽

Claudia M. Bazán ◽

María E. Bongiovanni ◽

Judith Toneatto ◽

Inés Albesa ◽

...

Keyword(s):

Oxidative Stress ◽

Escherichia Coli ◽

Staphylococcus Aureus ◽

Antimicrobial Activity ◽

Antibacterial Agents ◽

Antibacterial Activities ◽

Gram Negative Bacteria ◽

Gram Negative ◽

E Coli ◽

Diimine Ligands

The prevalence of antibiotic resistance has resulted in the need for new approaches to be developed to combat previously easily treatable infections. The main aim of this work was to establish the potential of the syntheticα-diimine chromium(III) and ruthenium(II) complexes (where theα-diimine ligands are bpy = 2,2-bipyridine, phen = 1,10-phenanthroline, and dppz = dipyrido[3,2-a:2′,3′-c]-phenazine) like [Cr(phen)3]3+, [Cr(phen)2(dppz)]3+, [Ru(phen)3]2+, and [Ru(bpy)3]2+as antibacterial agents by generating oxidative stress. The [Cr(phen)3]3+and [Cr(phen)2(dppz)]3+complexes showed activity against Gram positive and Gram negative bacteria with minimum inhibitory concentrations (MICs) ranging from 0.125 μg/mL to 1 μg/mL, while [Ru(phen)3]2+and [Ru(bpy)3]2+do not exhibit antimicrobial activity against the two bacterial genera studied at the concentration range used. When ciprofloxacin was combined with [Cr(phen)3]3+for the inhibition ofStaphylococcus aureusandEscherichia coli, an important synergistic effect was observed, FIC 0.066 forS. aureusand FIC 0.064 forE. coli. The work described here shows that chromium(III) complexes are bactericidal forS. aureusandE. coli. Our results indicate thatα-diimine chromium(III) complexes may be interesting to open new paths for metallodrug chemotherapy against different bacterial genera since some of these complexes have been found to exhibit remarkable antibacterial activities.

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Synergistic Effects of Anionic/Cationic Dendrimers and Levofloxacin on Antibacterial Activities

Molecules ◽

10.3390/molecules24162894 ◽

2019 ◽

Vol 24 (16) ◽

pp. 2894 ◽

Cited By ~ 10

Author(s):

Natalia Wrońska ◽

Jean Pierre Majoral ◽

Dietmar Appelhans ◽

Maria Bryszewska ◽

Katarzyna Lisowska

Keyword(s):

Antibacterial Activity ◽

Biomedical Applications ◽

Synergistic Effects ◽

Antibacterial Activities ◽

Drug Dosage ◽

General Interest ◽

Gram Negative Bacteria ◽

Gram Negative ◽

Fluoroquinolone Antibiotics ◽

Proteus Hauseri

Despite the numerous studies on dendrimers for biomedical applications, the antibacterial activity of anionic phosphorus dendrimers has not been explored. In our research, we evaluated the antibacterial activity of modified polycationic and polyanionic dendrimers in combination with levofloxacin (LVFX) against Gram-negative (Escherichia coli ATCC 25922, Proteus hauseri ATCC 15442) and Gram-positive (Staphylococcus aureus ATCC 6538) bacteria. In the case of Gram-negative bacteria, we concluded that a combination of dendrimers and antibiotic gave satisfactory results due to a synergistic effect. The use of fluoroquinolone antibiotics, such as LVFX, not only caused resistance in disease-causing microorganisms but also increased environmental pollution. Therefore, reduction of drug dosage is of general interest.

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Antibacterial and Antibiotic-Potentiating Activities of Thirteen Cameroonian Edible Plants against Gram-Negative Resistant Phenotypes

The Scientific World JOURNAL ◽

10.1155/2018/4020294 ◽

2018 ◽

Vol 2018 ◽

pp. 1-14 ◽

Cited By ~ 2

Author(s):

Paul Nayim ◽

Armelle T. Mbaveng ◽

Brice E. N. Wamba ◽

Aimé G. Fankam ◽

Joachim K. Dzotam ◽

...

Keyword(s):

Antibacterial Activities ◽

Multidrug Resistant ◽

Bark Extract ◽

Minimal Bactericidal Concentration ◽

Edible Plants ◽

Bacterial Strains ◽

Gram Negative ◽

Microdilution Method ◽

Multiresistant Bacteria ◽

Broth Microdilution Method

This work was designed to investigate the antibacterial activities of methanol extracts from thirteen Cameroonian edible plants and their antibiotic-potentiating effects against Gram-negative multidrug-resistant (MDR) phenotypes. The broth microdilution method was used to evaluate the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of the extracts, as well as their antibiotic-potentiating activities. The phytochemical screening of the extracts was carried out according to the standard methods. The results of phytochemical tests revealed the presence of sterols, polyphenols, and tannins in most of the tested extracts, with the other classes of secondary metabolites being selectively distributed. Tested extracts showed variable antibacterial activities with MIC values ranging from 64 to 1024 μg/mL. However, some extracts were significantly active against certain bacterial strains: seeds extract of Theobroma cacao (64 μg/mL) against Escherichia coli AG100Atet and Klebsiella pneumoniae K24, and the bark extract of Uapaca guineensis against E. coli ATCC 8739. The leaves extract of T. cacao displayed the best MBC values (256 μg/mL) against E. aerogenes EA27. Some tested extracts included extracts from the leaves of T. cacao and P. vulgaris, and the seeds of D. edulis and barks A. indica has selectively improved (2- to 64-fold) the antibacterial activities of some of the tested antibiotics, chloramphenicol (CHL), tetracycline (TET), kanamycin (KAN), streptomycin (STR), and erythromycin (ERY), against more than 70% of tested MDR bacteria. The findings of this work showed that tested plant extracts and particularly those from T. cacao and Phaseolus vulgaris can be used alone or in combination with conventional antibiotics in the treatment of infections involving multiresistant bacteria.

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

Chittagong University Journal of Biological Sciences ◽

10.3329/cujbs.v5i1.13378 ◽

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

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Cyanuric Chloride Containing Chalcones for Possible Breast Cancer Treatment: Synthesis, Antimicrobial and in silico Screening

Asian Journal of Chemistry ◽

10.14233/ajchem.2020.22461 ◽

2019 ◽

Vol 32 (2) ◽

pp. 408-414

Author(s):

Revathy Selvaraj ◽

J. Suresh ◽

A. Arun

Keyword(s):

Breast Cancer ◽

In Silico ◽

Topoisomerase Ii ◽

Excellent Result ◽

Screening Method ◽

Cyanuric Chloride ◽

Gram Negative Bacteria ◽

In Silico Screening ◽

Gram Negative ◽

Mic Value

In this work, we have synthesized efficient antibacterial compounds with anticancer novel molecules based on cyanuric chloride containing chalcone moiety. For this, novel triazine-based organic molecules were synthesized by using cyanuric chloride and 2,4-dichloro-1-ene(4-hydroxyphenyl)phenone and characterized by elemental analysis, FT-IR, NMR and UV-visible spectrometry techniques. Melting point of the molecules were increased with an increase in substitution on cyanuric chloride. The minimum inhibitory concentration (MIC) value of the synthesized compounds showed an excellent result on Gram-negative bacteria with low MIC value of 1.95 μg/mL. Gram-positive bacteria showed little resistance to the synthesized drug. The synthesized compounds were tested for their use as an anticancer drug using in silico screening method. The synthesized compounds in silico molecular docking method using breast cancer protein (BRCA2) confirms that triazine derivative with all three chlorine molecules replaced by 2,4-dichloro-1-ene(4-hydroxyphenyl)phenone showed highest binding energy with the value of -9.1900 Kcal/mol which is in agreement with the observed high MIC value obtained for Gram-negative bacteria. The synthesized molecules preferentially targeted the topoisomerase II of the bacteria. Overall, an efficient antimicrobial drug is synthesized using a simple preparation method.

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In Vitro and In Vivo Antibacterial Activities of DW-224a, a New Fluoronaphthyridone

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01407-05 ◽

2006 ◽

Vol 50 (6) ◽

pp. 2261-2264 ◽

Cited By ~ 36

Author(s):

Hee-Soo Park ◽

Hyun-Joo Kim ◽

Min-Jung Seol ◽

Dong-Rack Choi ◽

Eung-Chil Choi ◽

...

Keyword(s):

Antibacterial Activities ◽

The Other ◽

Vitro Activity ◽

Gram Negative Bacteria ◽

In Vitro Activity ◽

Gram Positive ◽

Gram Negative ◽

Gram Positive Bacteria

ABSTRACT DW-224a showed the most potent in vitro activity among the quinolone compounds tested against clinical isolates of gram-positive bacteria. Against gram-negative bacteria, DW-224a was slightly less active than the other fluoroquinolones. The in vivo activities of DW-224a against gram-positive bacteria were more potent than those of other quinolones.

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Cefotaxime and amikacin: results of in vitro and in vivo studies against Gram-negative bacteria and Staphylococcus aureus

Journal of Antimicrobial Chemotherapy ◽

10.1093/jac/6.suppl_a.55 ◽

1980 ◽

Vol 6 (suppl A) ◽

pp. 55-61 ◽

Cited By ~ 1

Author(s):

J. Klastersky ◽

H. Gaya ◽

S. H. Zinner ◽

C. Bernard ◽

J-C. Ryff ◽

...

Keyword(s):

Staphylococcus Aureus ◽

In Vivo Studies ◽

Gram Negative Bacteria ◽

Gram Negative ◽

And Staphylococcus Aureus

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An unusual case of chest pain

International Journal of Advances in Medicine ◽

10.18203/2349-3933.ijam20203131 ◽

2020 ◽

Vol 7 (8) ◽

pp. 1290

Author(s):

Saswat Subhankar ◽

K. Madhuri ◽

Vivek D. Alone

Keyword(s):

Staphylococcus Aureus ◽

Developing Countries ◽

Chest Pain ◽

Unusual Case ◽

Gram Negative Bacteria ◽

Pleural Effusions ◽

Gram Negative ◽

Competent Patient ◽

E Coli ◽

Gram Positive Bacteria

Osteomyelitis is an infection of the bones caused by pyogenic organisms. The ribs are an extremely uncommon site for osteomyelitis, occurring in less than 1% cases. The main causative organisms are Gram-positive bacteria, such as Staphylococcus aureus and Hemophilus influenzae. Gram-negative bacteria like E. coli have been rarely reported. Authors hereby present a case of an immune-competent patient who presented with an osteomyelitis of the ribs caused by the latter. In developing countries, tuberculosis is considered as the primary cause of osteomyelitis and pleural effusions. However, other organisms should also be considered in patients who present with fulminant infections.

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Formation in vitro of colistin resistance in carbapenem-resistant Gram-negative bacteria and its biological cost

Journal of microbiology epidemiology immunobiology ◽

10.36233/0372-9311-101 ◽

2021 ◽

Author(s):

D. V. Tapalski ◽

T. A. Petrovskaya ◽

A. E. Kozlov

Keyword(s):

Broth Culture ◽

Exponential Growth Phase ◽

Lag Phase ◽

Gram Negative Bacteria ◽

Colistin Resistance ◽

Gram Negative ◽

Broth Microdilution Method ◽

Resistant Mutants ◽

Biological Cost

Introduction. The spread of resistance to carbapenems among gram-negative bacteria have led to an increase in the consumption of polymyxins and the emergence of certain strains resistant to them. Polymyxin resistance is mainly associated with mutations in chromosomal genes. The development of mutational resistance to antibiotics can lead to a decrease in the viability of bacteria, which is manifested by an increase in the duration of the cell cycle, a decrease in virulence and competitive fitness. The purpose of the study was to assess in vitro the intensity of the formation of colistin resistance in carbapenemresistant clinical isolates of gram-negative bacteria, the stability of the formed emerged resistance and its biological cost.Materials and methods. For 46 strains of Klebsiella pneumoniae, 77 strains of Pseudomonas aeruginosa and 42 strains of Acinetobacter baumannii, real time polymerase chain reaction (PCR) was used to detect the genes of carbapenemases, the minimum inhibitory concentrations (MIC) of meropenem and colistin were determined by broth microdilution method. The selection of resistant subpopulations on Muller–Hinton agar with the addition of 16 mg/l colistin was carried out. For colistin-resistant mutants and their isogenic sensitive strains, the kinetic parameters of growth in broth culture were determined. Incubation and result recording were performed on an Infinite M200 microplate reader for 18.5 hours at 35°C with measurement of light scatter in the wells every 15 minutes.Results. The production of carbapenemases MBL VIM in P. aeruginosa, MBL NDM, KPC and OXA-48 in K. pneumoniae, OXA-23 and OXA-40 in A. baumannii was observed. All strains were sensitive to colistin (MIC varied from 0.062 to 2 mg/l). The colony growth on a selective medium with16 mg/l colistin was observed for 97.8% of K. pneumoniae strains, 16.9% of P. aeruginosa strains, and 61.9% of A. baumannii strains. The mutational nature of colistin resistance was confirmed for 21.7% of K. pneumoniae strains. For colistin-resistant mutants of K. pneumoniae, a significant increase in the duration of the lag phase (Tlag) was observed: 225.6 ± 7.037 min in the wild-type susceptible strains and 245.5 ± 8.726 in resistant mutants, p = 0.037. The indicators of the doubling time of the number of microbial cells in the exponential growth phase (Tdoubling) and the area under the bacterial growth curve did not differ significantly.Conclusion. A high frequency of formation of colistin resistance in vitro in carbapenemase-producing strains of K. pneumoniae was observed. The absence of significant changes in the kinetics of microbial growth in resistant strains makes it possible to predict the further spread of mutational resistance to colistin, as well as its preservation in microbial populations of K. pneumoniae even in the case of limiting the use of this antibiotic.

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