scholarly journals Sigmoid E max Modelling to Define the Fixed Concentration of Enmetazobactam for MIC Testing in Combination with Cefepime

2021 ◽  
Author(s):  
Philipp Knechtle ◽  
Stuart Shapiro ◽  
Ian Morrissey ◽  
Cyntia De Piano ◽  
Adam Belley
Keyword(s):  
Antibacterial Activity ◽  
Minimum Inhibitory Concentration ◽  
Klebsiella Pneumoniae ◽  
Inhibitory Concentration ◽  
Carbapenem Resistance ◽  
Clinical Isolates ◽  
Extended Spectrum ◽  
Fixed Concentration

Use of carbapenem antibiotics to treat infections caused by Enterobacterales expressing increasingly aggressive extended-spectrum β-lactamases (ESBL) has contributed to the emergence of carbapenem resistance. Enmetazobactam is a novel ESBL inhibitor being developed in combination with cefepime as a carbapenem-sparing option for infections caused by ESBL-producing Enterobacterales . Cefepime-enmetazobactam checkerboard minimum inhibitory concentration (MIC) profiles were obtained for a challenge panel of cefepime-resistant ESBL-producing clinical isolates of Klebsiella pneumoniae . Sigmoid E max modelling described cefepime MIC as a function of enmetazobactam concentration with no bias. A concentration of 8 μg/ml enmetazobactam proved sufficient to restore >95% of cefepime antibacterial activity in vitro against >95% of isolates tested. These results support a fixed concentration of 8 μg/ml of enmetazobactam for MIC testing.

scholarly journals In vitro emergence of carbapenem resistance in extended-spectrum β-lactamase-producing Klebsiella pneumoniae clinical isolates

2015 ◽  
Vol 9 (02) ◽  
pp. 218-221
Author(s):  
Hugo E Villar ◽  
Gabriela Santana ◽  
Monica B Jugo ◽  
Patricia Perren ◽  
Mariana Hidalgo ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Full Text ◽  
Carbapenem Resistance ◽  
Clinical Isolates ◽  
Extended Spectrum

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

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.

In-Vitro Studies on the Sensitivity of Staphylococcus aureus to Some Ethno-Medicinal Preparations Sold around Kano, Nigeria

2011 ◽  
Vol 4 (1) ◽  
pp. 22-25 ◽  
Author(s):  
M Bashir ◽  
I Yusuf ◽  
AS Kutama
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Test Organism ◽  
Ethanolic Extract ◽  
Screening Tests ◽  
Phytochemical Screening ◽  
Herbal Preparations

Five traditional herbal preparations were sampled between May-June, 2009 in Kano. The samples were investigated for invitro antibacterial activities against clinical isolates of Staphylococcus aureus. Likewise, phytochemical screening tests were conducted to determine some of the phytochemicals present in the ethanolic and water extracts of the samples. Various concentrations of the extracts were prepared using serial doubling dilutions (5000=l/ml, 2500=g/ml, 1250=g/ml, 625=g/ml and 312.5=g/ml). All the test extracts showed slight antibacterial activity against the test organism, with ethanolic extract of sample E having the highest zone diameter of inhibition, while sample H had the lowest diameter of inhibition. The standard antibiotic disc (Gentamicin) had demonstrated the highest activity on the test organisms. The results of the Phytochemical screening revealed the presence of steroid in all the samples, tannin in samples A, C, D and E, reducing sugars in sample A, D and E respectively. The result of the minimum inhibitory concentration (MIC) was found to be above 312.5=g/ml for samples C, D and E. Keywords: Staphylococcus aureus, Herbal preparations, antibacterial activity, Phytochemical screening and minimum inhibitory concentration.

scholarly journals In Vitro Activity of Essential Oils Against Planktonic and Biofilm Cells of Extended-Spectrum β-Lactamase (ESBL)/Carbapenamase-Producing Gram-Negative Bacteria Involved in Human Nosocomial Infections

Antibiotics ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 272 ◽  
Author(s):  
Ramona Iseppi ◽  
Alessandro Di Cerbo ◽  
Piero Aloisi ◽  
Mattia Manelli ◽  
Veronica Pellesi ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Klebsiella Pneumoniae ◽  
Essential Oils ◽  
Disk Diffusion ◽  
Mentha Piperita ◽  
Thymus Vulgaris ◽  
Extended Spectrum ◽  
Disk Diffusion Assay ◽  
Diffusion Assay

The aim of this study was to analyze the antibacterial activity of four essential oils (EOs), Melaleuca alternifolia, Eucalyptus globulus, Mentha piperita, and Thymus vulgaris, in preventing the development and spread of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae, metallo-beta-lactamase (MBL)-producing Pseudomonas aeruginosa and carbapenemase (KPC)-producing Klebsiella pneumoniae. A total of 60 strains were obtained from the stock collection from the Microbiology Laboratory of Hesperia Hospital, Modena, Italy. Twenty ESBL-producing E. coli, 5 K. pneumoniae, 13 KPC-producing K. pneumoniae, and 20 MBL-producing P. aeruginosa were cultured and reconfirmed as ESBL and carbapenamase producers. Polymerase chain reaction was used for the detection of genes responsible for antibiotic resistance (ESBL and KPC/MBL). Antibacterial activity of the EOs was determined using the agar disk diffusion assay, and minimal inhibitory concentrations (MICs) were also evaluated. Lastly, adhesion capability and biofilm formation on polystyrene and glass surfaces were studied in 24 randomly selected strains. M. alternifolia and T. vulgaris EOs showed the best antibacterial activity against all tested strains and, as revealed by agar disk diffusion assay, M. alternifolia was the most effective, even at low concentrations. This effect was also confirmed by MICs, with values ranging from 0.5 to 16 µg/mL and from 1 to 16 µg/mL, for M. alternifolia and T. vulgaris EOs, respectively. The EOs’ antibacterial activity compared to antibiotics confirmed M. alternifolia EO as the best antibacterial agent. T. vulgaris EO also showed a good antibacterial activity with MICs lower than both reference antibiotics. Lastly, a significant anti-biofilm activity was observed for the two EOs (*P < 0.05 and **P < 0.01 for M. alternifolia and T. vulgaris EOs, respectively). A good antibacterial and anti-biofilm activity of M. alternifolia and T. vulgaris EOs against all selected strains was observed, thus demonstrating a future possible use of these EOs to treat infections caused by ESBL/carbapenemase-producing strains, even in association with antibiotics.

scholarly journals Antibacterial and Hemolytic Activity of Crotalus triseriatus and Crotalus ravus Venom

Animals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 281
Author(s):  
Adrian Zaragoza-Bastida ◽  
Saudy Consepcion Flores-Aguilar ◽  
Liliana Mireya Aguilar-Castro ◽  
Ana Lizet Morales-Ubaldo ◽  
Benjamín Valladares-Carranza ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibacterial Activity ◽  
Minimum Inhibitory Concentration ◽  
Hemolytic Activity ◽  
Inhibitory Concentration ◽  
Minimum Bactericidal Concentration ◽  
The Other ◽  
Medical Treatments ◽  
First Time

Rattlesnakes have venoms with a complex toxin mixture comprised of polypeptides and proteins. Previous studies have shown that some of these polypeptides are of high value for the development of new medical treatments. The aim of the present study is to evaluate, in vitro, the antibacterial and hemolytic activity of Crotalus triseriatus and Crotalus ravus venoms. A direct field search was conducted to obtain Crotalus triseriatus and Crotalus ravus venom samples. These were evaluated to determine their antibacterial activity against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa through the techniques of Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC). Hemolytic activity was also determined. Antibacterial activity was determined for treatments (Crotalus triseriatus 2) CT2 and (Crotalus ravus 3) CR3, obtaining a Minimum Inhibitory Concentration of 50 µg/mL and a Minimum Bactericidal Concentration of 100 µg/mL against Pseudomonas aeruginosa. CT1 (Crotalus triseriatus 1), CT2, and CR3 presented hemolytic activity; on the other hand, Crotalus ravus 4 (CR4) did not show hemolytic activity. The results of the present study indicate for the first time that Crotalus triseriatus and Crotalus ravus venoms contain some bioactive compounds with bactericidal activity against Pseudomonas aeruginosa which could be used as alternative treatment in diseases caused by this pathogenic bacterium.

scholarly journals Klebsiella pneumoniae Planktonic and Biofilm Reduction by Different Plant Extracts: In Vitro Study

2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
Lucas Paula-Ramos ◽  
Carlos Eduardo da Rocha Santos ◽  
Daphne Camargo Reis Mello ◽  
Lígia Nishiama Theodoro ◽  
Felipe Eduardo De Oliveira ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Minimum Inhibitory Concentration ◽  
Klebsiella Pneumoniae ◽  
Inhibitory Concentration ◽  
Juglans Regia ◽  
In Vitro Study ◽  
Chlorhexidine Digluconate ◽  
Planktonic Form ◽  
Microdilution Broth

This study evaluated the action of Pfaffia paniculata K., Juglans regia L., and Rosmarius officinalis L. extracts against planktonic form and biofilm of Klebsiella pneumoniae (ATCC 4352). Minimum inhibitory concentration (MIC) and minimum microbicidal concentration (MMC) values were determined for each extract by microdilution broth method, according to Clinical and Laboratory Standards Institute. Next, antimicrobial activity of the extracts on biofilm was analyzed. For this, standardized suspension at 107 UFC/mL of K. pneumoniae was distributed into 96-well microplates (n=10) and after 48 h at 37°C and biofilm was subjected to treatment for 5 min with the extracts at a concentration of 200 mg/mL. ANOVA and Tukey tests (5%) were used to verify statistical significant reduction (p<0.05) of planktonic form and biofilm. P paniculata K., R. officinalis L., and J. regia L. showed reductions in biomass of 55.6, 58.1, and 18.65% and cell viability reduction of 72.4, 65.1, and 31.5%, respectively. The reduction obtained with P. paniculata and R. officinalis extracts was similar to the reduction obtained with chlorhexidine digluconate 2%. In conclusion, all extracts have microbicidal action on the planktonic form but only P. paniculata K. and R. officinalis L. were effective against biofilm.

scholarly journals Synthesis and in vitro Antibacterial Activity of Quaternization 10-Methoxycanthin-6-one Derivatives

2019 ◽  
Author(s):  
Na Li ◽  
Jiang-Kun Dai ◽  
Dan Liu ◽  
Jin-Yi Wang ◽  
Jun-Ru Wang
Keyword(s):  
Antibacterial Activity ◽  
Natural Products ◽  
Minimum Inhibitory Concentration ◽  
Pathogenic Bacteria ◽  
Antibacterial Agents ◽  
Inhibitory Concentration ◽  
Dilution Method ◽  
In Vitro Antibacterial Activity

Natural products are an important source of antibacterial agents. Canthin-6-one alkaloids have displayed potential antibacterial activity based on our previous work. In order to improve the activity, twenty-two new 3-N-benzylated 10-methoxy canthin-6-ones were designed and synthesized through quaternization reaction. The in vitro antibacterial activity against three bacteria was evaluated by double dilution method. Four compounds (6f, 6i, 6p and 6t) displayed 2-fold superiority (minimum inhibitory concentration (MIC) = 3.91 &micro;g/mL) against agricultural pathogenic bacteria R. solanacearum and P. syringae than agrochemical propineb. Moreover, the structure&ndash;activity relationships (SARs) were also carefully summarized in order to guide the development of antibacterial canthin-6-one agents.

scholarly journals STUDY CYTOTOXICITY, ANTIBACTERIAL ACTIVITY, AND COMPOSITIONS BY FT-IR AND GC-MS FOR ORGANIC EXTRACT OF WHITE IRAQI DESERT TRUFFLE TIRMANIA NIVEA

2020 ◽  
Vol 17 (36) ◽  
pp. 18-31
Author(s):  
Ahmad khadem HACHIM ◽  
Rashid Rahim HATEET ◽  
Tawfik Muhammad MUHSIN
Keyword(s):  
Antibacterial Activity ◽  
Minimum Inhibitory Concentration ◽  
Cell Line ◽  
Pathogenic Bacteria ◽  
Inhibitory Concentration ◽  
Biological Activities ◽  
Gas Chromatography Mass Spectrometry ◽  
Bacterial Strains ◽  
Organic Extract

The purpose of the present work aimed at exploring the potential biochemical components and biological activities of an organic extract of the white truffle Tirmania nivea collected from the Iraqi desert, then test the organic extract against the Cytotoxicity on Human Larynx carcinoma cells and selected strains of pathogenic bacteria. Fourier transform infrared spectroscopy (FTIR) and gas chromatography-mass spectrometry GC/MSS were used to analyze mycochemical compositions. The antibacterial activity and Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) was investigated using a disk diffusion agar method. The truffle extract's cytotoxicity effect against the larynx cell line (Hep-2) was assessed by the MTT assay (in vitro). FTIR results provided the presence of phenol, carboxylic acid, and alkane's functional group, The GC-MS analysis of T. nivea disclose the existence of nineteen compounds that can contribute to the pharmaceutical properties of the truffle. As for antibacterial activity result, A growth inhibition activity of truffle extract at (18-40 mm inhibition zones) against the tested pathogenic bacterial strains was detected, which minimum inhibitory concentration values ranged from 3.12 to 6.25 mg/mL for Escherichia coli (ATCC 25922) and Staphylococcus aureus (ATCC 25923) Respectively. The results of cytotoxicity shown that the organic truffle extract exhibited a high inhibitory rate (52.685%) against cell line (Hep-2) at a concentration of 1.56 ?g/mL. In this work, the results showed that the organic extracts of T. nivea are very promising as cancer cytotoxicity and antibacterial agent for future medical applications.

scholarly journals In Vitro Activities of the Potent, Broad-Spectrum Carbapenem MK-0826 (L-749,345) against Broad-Spectrum β-Lactamase-and Extended-Spectrum β-Lactamase-Producing Klebsiella pneumoniae and Escherichia coli Clinical Isolates

1999 ◽  
Vol 43 (5) ◽  
pp. 1170-1176 ◽  
Author(s):  
Joyce Kohler ◽  
Karen L. Dorso ◽  
Katherine Young ◽  
Gail G. Hammond ◽  
Hugh Rosen ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Pneumoniae ◽  
Broad Spectrum ◽  
Bacterial Resistance ◽  
Clinical Isolates ◽  
Inoculum Level ◽  
E Coli ◽  
Extended Spectrum ◽  
Group 1

ABSTRACT An important mechanism of bacterial resistance to β-lactam antibiotics is inactivation by β-lactam-hydrolyzing enzymes (β-lactamases). The evolution of the extended-spectrum β-lactamases (ESBLs) is associated with extensive use of β-lactam antibiotics, particularly cephalosporins, and is a serious threat to therapeutic efficacy. ESBLs and broad-spectrum β-lactamases (BDSBLs) are plasmid-mediated class A enzymes produced by gram-negative pathogens, principallyEscherichia coli and Klebsiella pneumoniae. MK-0826 was highly potent against all ESBL- and BDSBL-producingK. pneumoniae and E. coli clinical isolates tested (MIC range, 0.008 to 0.12 μg/ml). In E. coli, this activity was associated with high-affinity binding to penicillin-binding proteins 2 and 3. When the inoculum level was increased 10-fold, increasing the amount of β-lactamase present, the MK-0826 MIC range increased to 0.008 to 1 μg/ml. By comparison, similar observations were made with meropenem while imipenem MICs were usually less affected. Not surprisingly, MIC increases with noncarbapenem β-lactams were generally substantially greater, resulting in resistance in many cases. E. coli strains that produce chromosomal (Bush group 1) β-lactamase served as controls. All three carbapenems were subject to an inoculum effect with the majority of the BDSBL- and ESBL-producers but not the Bush group 1 strains, implying some effect of the plasmid-borne enzymes on potency. Importantly, MK-0826 MICs remained at or below 1 μg/ml under all test conditions.

scholarly journals IN VITRO AND IN SILICO ANTIBACTERIAL ACTIVITY OF 1.5-BIS (3’-ETHOXY-4’-HYDROXYPHENYL)-1-4-PENTADIENE-3-ONE

2018 ◽  
Vol 10 (5) ◽  
pp. 70
Author(s):  
Agus Purwanggana ◽  
Esti Mumpuni ◽  
Esti Mulatsari
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Minimum Inhibitory Concentration ◽  
Staphylococcus Epidermidis ◽  
In Silico ◽  
Inhibitory Concentration ◽  
Inhibition Zone ◽  
Antibacterial Study

Objective: The main objective of this research were screened in vitro and in silico of 1,5-bis (3'-ethoxy-4'-hydroxyphenyl)-1,4-pentadiene-3-one as potential antibacterial agents.Methods: The in vitro antibacterial study was carried against Staphylococcus aureus, Staphylococcus epidermidis (gram positive) and Escherichia coli, Salmonella thypi (gram negative) using broth dilution method to determine Minimum Inhibitory Concentration (MIC), disc diffusion method to determine the diameter of inhibition zone. In silico antibacterial study was carried using computational software Protein-Ligand ANT System (PLANTS), computational docking was carried using receptor with Protein Data Bank (PDB) file 3MZD. The structures were optimized prior docking using YASARA, and MarvinSketch. The results of antibacterial testing were compared to two positive control drugs i. e amoxicillin and cefadroxil.Results: In vitro evaluation showed that 1,5-bis (3'-ethoxy-4'-hydroxyphenyl)-1,4-pentadiene-3-one has a better antibacterial activity than amoxicillin and cefadroxil with a Minimum Inhibitory Concentration (MIC) of 0.15 ppm and diameter of inhibition zone of 11.27±0.31, 11.35±0.39, 11.25±0.33, and 11.05±0.45 mm in Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, and Salmonella thypi, respectively. These results in line with in silico evaluation that showed 1,5-bis (3'-ethoxy-4'-hydroxyphenyl)-1,4-pentadiene-3-one has more negative docking score than amoxicillin, cefadroxil, and cloxacillin acyl as a native ligand on the 3MZD receptor.Conclusion: This results obtained in this research work were 1,5-bis (3'-ethoxy-4'-hydroxyphenyl)-1,4-pentadiene-3-one compound potential as an antibacterial agent. 

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