scholarly journals The In Vitro Susceptibility of Biofilm Forming Medical Device Related Pathogens to Conventional Antibiotics

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Garry Laverty ◽  
Mahmoud Y. Alkawareek ◽  
Brendan F. Gilmore
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Staphylococcus Epidermidis ◽  
Inhibitory Concentration ◽  
Minimum Bactericidal Concentration ◽  
Broth Microdilution ◽  
In Vitro Susceptibility ◽  
Conventional Antibiotics ◽  
Kinetics Of

Minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and minimum biofilm eradication concentration (MBEC) and kill kinetics were established for vancomycin, rifampicin, trimethoprim, gentamicin, and ciprofloxacin against the biofilm forming bacteria Staphylococcus epidermidis (ATCC 35984), Staphylococcus aureus (ATCC 29213), Methicillin Resistant Staphylococcus aureus (MRSA) (ATCC 43300), Pseudomonas aeruginosa (PAO1), and Escherichia coli (NCTC 8196). MICs and MBCs were determined via broth microdilution in 96-well plates. MBECs were studied using the Calgary Biofilm Device. Values obtained were used to investigate the kill kinetics of conventional antimicrobials against a range of planktonic and biofilm microorganisms over a period of 24 hours. Planktonic kill kinetics were determined at 4xMIC and biofilm kill kinetics at relative MBECs. Susceptibility of microorganisms varied depending on antibiotic selected and phenotypic form of bacteria. Gram-positive planktonic isolates were extremely susceptible to vancomycin (highest MBC: 7.81 mg L−1: methicillin sensitive and resistant S. aureus) but no MBEC value was obtained against all biofilm pathogens tested (up to 1000 mg L−1). Both gentamicin and ciprofloxacin displayed the broadest spectrum of activity with MIC and MBCs in the mg L−1 range against all planktonic isolates tested and MBEC values obtained against all but S. epidermidis (ATCC 35984) and MRSA (ATCC 43300).

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. 

scholarly journals Antimicrobial Susceptibility ofEscherichia coliStrains Isolated fromAlouattaspp. Feces to Essential Oils

2016 ◽  
Vol 2016 ◽  
pp. 1-4 ◽  
Author(s):  
Valéria Maria Lara ◽  
Adriano Bonfim Carregaro ◽  
Deise Flores Santurio ◽  
Mariangela Facco de Sá ◽  
Janio Moraes Santurio ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Essential Oils ◽  
Inhibitory Concentration ◽  
Minimum Bactericidal Concentration ◽  
Thymus Vulgaris ◽  
Broth Microdilution ◽  
Eucalyptus Citriodora ◽  
Cymbopogon Citratus

This study evaluated thein vitroantibacterial activity of essential oils fromLippia graveolens(Mexican oregano),Origanum vulgaris(oregano),Thymus vulgaris(thyme),Rosmarinus officinalis(rosemary),Cymbopogon nardus(citronella),Cymbopogon citratus(lemongrass), andEucalyptus citriodora(eucalyptus) againstEscherichia coli(n=22) strains isolated fromAlouattaspp. feces. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined for each isolate using the broth microdilution technique. Essential oils of Mexican oregano (MIC mean = 1818 μg mL−1; MBC mean = 2618 μg mL−1), thyme (MIC mean = 2618 μg mL−1; MBC mean = 2909 μg mL−1), and oregano (MIC mean = 3418 μg mL−1; MBC mean = 4800 μg mL−1) showed the best antibacterial activity, while essential oils of eucalyptus, rosemary, citronella, and lemongrass displayed no antibacterial activity at concentrations greater than or equal to 6400 μg mL−1. Our results confirm the antimicrobial potential of some essential oils, which deserve further research.

Impact of pH on growth of Staphylococcus epidermidis and Staphylococcus aureus in vitro

2021 ◽  
Vol 70 (9) ◽  
Author(s):  
Vidula Iyer ◽  
Janhavi Raut ◽  
Anindya Dasgupta
Keyword(s):  
Staphylococcus Aureus ◽  
Growth Kinetics ◽  
Staphylococcus Epidermidis ◽  
Type Species ◽  
Ph Dependence ◽  
Skin Microbiome ◽  
Content Type ◽  
Link Type ◽  
Kinetics Of

The pH of skin is critical for skin health and resilience and plays a key role in controlling the skin microbiome. It has been well reported that under dysbiotic conditions such as atopic dermatitis (AD), eczema, etc. there are significant aberrations of skin pH, along with a higher level of Staphylococcus aureus compared to the commensal Staphylococcus epidermidis on skin. To understand the effect of pH on the relative growth of S. epidermidis and S. aureus , we carried out simple in vitro growth kinetic studies of the individual microbes under varying pH conditions. We demonstrated that the growth kinetics of S. epidermidis is relatively insensitive to pH within the range of 5–7, while S. aureus shows a stronger pH dependence in that range. Gompertz’s model was used to fit the pH dependence of the growth kinetics of the two bacteria and showed that the equilibrium bacterial count of S. aureus was the more sensitive parameter. The switch in growth rate happens at a pH of 6.5–7. Our studies are in line with the general hypothesis that keeping the skin pH within an acidic range is advantageous in terms of keeping the skin microbiome in balance and maintaining healthy skin.

scholarly journals Actividad antibacteriana in vitro de aceites esenciales de diferentes especies del género Citrus

2017 ◽  
Vol 46 (2) ◽  
Author(s):  
Miladys Esther Torrenegra Alarcón ◽  
Nerlis Paola Pájaro ◽  
Glicerio León Méndez
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Klebsiella Pneumoniae ◽  
Staphylococcus Epidermidis ◽  
E Coli

Se evaluó la actividad antibacteriana in vitro de aceites esenciales de diferentes especiesdel género Citrus frente a cepas ATCC de Staphylococcus aureus, Staphylococcus epidermidis,Klebsiella pneumoniae, Pseudomonas aeruginosa y Escherichia coli, determinandola concentración mínima inhibitoria (CMI) y la concentración mínima bactericida(CMB). Las bacterias se replicaron en medios de agar y caldos específicos. Se determinóel momento de máxima densidad óptica (DO620) para emplearlo como tiempode incubación; luego se hicieron pruebas de evaluación de sensibilidad con la exposiciónde las cepas a concentraciones a 1000 g/mL del extracto en caldo. Para solubilizarse empleó dimetilsulfóxido (DMSO) al 1%. Posteriormente, se le determinó laconcentración mínima inhibitoria mediante metodologías de microdilución en caldoy la concentración mínima bactericida. Encontrándose una actividad de los aceitesesenciales del género Citrus, con valores de CMI ≥ 600 mg/mL frente a S. aureus,S. epidermidis, K. pneumoniae, P. aeruginosa y E. coli. En función a los resultados obtenidos,se concluye que las diferentes especies del género Citrus son consideradas comopromisorias para el control del componente bacteriano.

scholarly journals Phenotypic aspects of oral strains of Candida albicans in children with down's syndrome

2006 ◽  
Vol 66 (3) ◽  
pp. 939-944 ◽  
Author(s):  
E. L. Ribeiro ◽  
M. L. Scroferneker ◽  
M. S. Cavalhaes ◽  
C. C. Campos ◽  
G. M. Nagato ◽  
...  
Keyword(s):  
Inhibitory Concentration ◽  
Down's Syndrome ◽  
Test Group ◽  
Down’S Syndrome ◽  
Antifungal Drugs ◽  
Control Group ◽  
Broth Microdilution ◽  
In Vitro Susceptibility ◽  
Biological Aspects

The aim of this article is to characterize the biological aspects of oral strains of C. albicans in children with Down's syndrome. These yeasts were analyzed as to their macromorphological and enzymatic aspects and were tested as to their in vitro susceptibility to antifungal drugs using broth microdilution to determine the minimum inhibitory concentration (MIC). The morphotyping revealed that all oral C. albicans isolates from children with Down's syndrome promoted the formation of fringes regardless of size, while the control group presented smaller fringes. All oral C. albicans strains produced proteinase, but those with phospholipolytic activity showed greater enzyme capacity in the test group. In vitro susceptibility showed that all oral C. albicans isolates were sensitive to the drugs used.

ID: 49: STUDY OF MINIMUM INHIBITORY CONCENTRATION OF CEFAZOLIN FOR METHICILLIN SENSITIVE STAPHYLOCOCCUS AUREUS AND CORRELATION WITH OXACILLIN SUSCEPTIBILITY

2016 ◽  
Vol 64 (4) ◽  
pp. 954.2-954
Author(s):  
C Quarshie ◽  
J Koirala ◽  
V Sundareshan
Keyword(s):  
Staphylococcus Aureus ◽  
Standard Deviation ◽  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Medical Center ◽  
Generation Cephalosporin ◽  
In Vitro Susceptibility ◽  
Suitable Alternative ◽  
High Level

BackgroundCefazolin, a first generation cephalosporin, has been used for the treatment of Methicillin Sensitive Staphylococcus aureus (MSSA) infections since the 1970s. There have now been reported cases of failed therapy with cefazolin. High-level β-lactamase producing strains of S. aureus can inactivate the susceptible β-lactam (cefazolin) at a rate high enough to overcome its antibacterial effect. These strains typically have a high Minimum Inhibitory Concentration (MIC) for cefazolin when a large inoculum is used. About 20% of MSSA isolates have been shown to have a substantial inoculum effect suggesting that cefazolin treatment might be associated with clinical failure in serious MSSA infections. The minimum inhibition concentration (MIC) for cefazolin is not provided on all standard sensitivity panels and susceptibility is extrapolated from the report on oxacillin. The goal of this study was to analyze the MIC of cefazolin for MSSA isolates to determine the correlation of cefazolin susceptibility and in vitro susceptibility of oxacillin. We also evaluated the MIC of alternative antibiotics as part of this study for use in patients that might be allergic to penicillin.MethodThirty two isolates of MSSA were randomly selected from repositories of isolates at Memorial Medical Center hospital's microbiology department from 2015. The isolates were from patients with a wide variety of diagnoses, including bacteremia, osteomyelitis and wound infections. S. aureus ATCC 29213 was used as controls. MICs were determined by a Kirby Bauer method for cefazolin and Epsilometer test for other antibiotics that were studied. Inocula were standardized using optical density measurements, with determinations of CFU/ml to determine the inoculum concentrations. IN addition to cefazolin, we obtained the MIC for daptomycin, oxacillin, ceftaroline and telavancin as well.ResultsOf the thirty two MSSA isolates tested, 100% were susceptible to cefazolin. The mean zone of inhibition (ZOI) was 29.18 with standard deviation of 3.67 for cefazolin (29–35 mm ZOI with ATCC strains of MSSA) . All the isolates were susceptible to Oxacillin with mean MIC of 0.7735 with standard deviation of 0.30. Daptomycin, ceftaroline and telavancin were 100% susceptible with mean MIC of 0.27, 0.25, and 0.07, respectively. All isolates were studied for the alternate antibiotics and no resistance was noted.ConclusionThe MIC of cefazolin for MSSA determined by in vitro susceptibility to oxacillin was entirely in the susceptible range with 100% correlation. Daptomycin, ceftaroline and telavancin are suitable alternative antibiotics for treatment of patients with infections due to MSSA in whom anti-staphylococcal penicillins cannot be used due to penicillin allergic, intolerance, and/or non-availability since there is not much resistance to these antibiotics in MSSA.

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 Composición química del aceite esencial de Petroselinum crispum (Mill) Nyman ex A.W. Hill “perejil” y determinación de su actividad antibacteriana

2012 ◽  
Vol 15 (2) ◽  
pp. 78-83
Author(s):  
Reider Vivanco T ◽  
Enrique León S ◽  
Américo Castro L ◽  
Norma J Ramos C
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Bacillus Subtilis ◽  
Staphylococcus Epidermidis ◽  
Petroselinum Crispum

El estudio tuvo como objetivo analizar la composición química del aceite esencial de las hojas de Petroselinum crispum (Mill) Nyman ex A.W. Hill “perejil” y determinar su actividad antibacteriana. El aceite esencial se obtuvo tratando 20 kg de hojas frescas con un equipo de destilación por arrastre con vapor de agua; obteniéndose cuatro mililitros y un rendimiento de 0,02 por ciento v/p. En el análisis cualitativo se analizó su solubilidad en solventes orgánicos; los componentes químicos se determinaron por cromatografía de Gases/ Espectrometría de Masas (CG/EM), lográndose la elucidación de los siguientes compuestos: 1R-α-pineno, β-pineno, β-felandreno, p, α-dimetil estireno, (E)-2-caren-4-ol, 1,3-benzodioxol, 4-metoxi-6-(2-propenil)-, y 1,3-benzodioxol,4,7-dimetoxy-5-(2-propenil)-. La determinación de la actividad antibacteriana in vitro, se realizó por el método de difusión en agar, demostrándose actividad significativa frente a Staphylococcus aureus ATCC 25933 y Staphylococcus epidermidis cepa clínica, a las concentraciones de 100 y 50 por ciento; y para Pseudomonas aeruginosa ATCC 2783 a la concentración de 100 por ciento, teniendo de poca a ninguna actividad frente a Bacillus subtilis y Escherichia coli. Los resultados obtenidos muestran que el aceite esencial de Petroselinum crispum (Mill) Nyman ex A.W. Hill “perejil” presenta actividad antibacteriana.

scholarly journals Antimicrobial Activity of Nisin and Lysozyme on Foodborne Pathogens Listeria Monocytogenes, Staphylococcus Aureus, Salmonella Typhimurium, and Escherichia Coli at Different pH

2018 ◽  
Author(s):  
Hamdollah Moshtaghi ◽  
Azadeh Rashidimehr ◽  
Behzad Shareghi
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Listeria Monocytogenes ◽  
Foodborne Pathogens ◽  
Inhibitory Concentration ◽  
Low Ph ◽  
Bacteria Growth ◽  
Microdilution Method ◽  
Natural Preservatives

Background: To prevent or inhibit the growth of pathogenic microorganisms and food spoilage factors, many studies have been done by using natural preservatives. The aim of study was to investigate the effect of different concentrations of lysozyme and Nisin on the growth rate and also to determine the minimum inhibitory concentration (MIC) and minimum bactericidal cocentratiin (MBC) of these combinations on the bacteria of Escherichia coli, Staphylococcus aureus, Salmonella typhimorium and Listeria monocytogenes. Methods: In this study, various concentrations of lysozyme and Nisin were set in form of alone concentration and in combination concentrations (0, 19.53, 39.06, 78.13, 156.25, 312.5, 625, 1250, 2500, 5000) in vitro conditions and 6 pH 5.5, 6, 6.5, 7, 7.5, and 8. Microdilution method at 24°C was done and the combined effect on bacteria growth was read by using ELISA reader. Results: The results showed that lysozyme was less effective on Escherichia coli and Nisin was less effective on Listeria monocytogenes. Moreover, combining lysozyme and Nisin at low pH decreased the MIC. Conclusions: The results of the study showed that the effect of combining lysozyme and Nisin on Staphylococcus aureus is above all other bacteria and at low pH reduces the MIC.

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