scholarly journals Broad-Spectrum Antibacterial Peptide Kills Extracellular and Intracellular Bacteria Without Affecting Epithelialization

2021 ◽  
Vol 12 ◽  
Author(s):  
Anala Nepal ◽  
Synnøve Brandt Ræder ◽  
Caroline Krogh Søgaard ◽  
Maria Schei Haugan ◽  
Marit Otterlei
Keyword(s):  
Staphylococcus Epidermidis ◽  
Inhibitory Concentration ◽  
Intracellular Bacteria ◽  
Skin Infections ◽  
Hacat Keratinocytes ◽  
Resistance Development ◽  
Infection Models ◽  
Long Time ◽  
Eskape Pathogens

New antibacterial drugs with novel modes of action are urgently needed as antibiotic resistance in bacteria is increasing and spreading throughout the world. In this study, we aimed to explore the possibility of using APIM-peptides targeting the bacterial β-clamp for treatment of skin infections. We selected a lead peptide, named betatide, from five APIM-peptide candidates based on their antibacterial and antimutagenic activities in both G+ and G– bacteria. Betatide was further tested in minimal inhibitory concentration (MIC) assays in ESKAPE pathogens, in in vitro infection models, and in a resistance development assay. We found that betatide is a broad-range antibacterial which obliterated extracellular bacterial growth of methicillin-resistant Staphylococcus epidermidis (MRSE) in cell co-cultures without affecting the epithelialization of HaCaT keratinocytes. Betatide also reduced the number of intracellular Staphylococcus aureus in infected HaCaT cells. Furthermore, long-time exposure to betatide at sub-MICs induced minimal or no increase in resistance development compared to ciprofloxacin and gentamicin or ampicillin in S. aureus and Escherichia coli. These properties support the potential of betatide for the treatment of topical skin infections.

scholarly journals In Vitro Time-Kill of Common Ocular Pathogens with Besifloxacin Alone and in Combination with Benzalkonium Chloride

2021 ◽  
Vol 14 (6) ◽  
pp. 517
Author(s):  
Joseph Blondeau ◽  
Heleen DeCory
Keyword(s):  
Staphylococcus Epidermidis ◽  
Benzalkonium Chloride ◽  
Bacterial Species ◽  
Drug Resistant ◽  
Resistance Development ◽  
Aureus Isolate ◽  
Killing Activity ◽  
Time Kill ◽  
Variable Impact

Background: Besifloxacin ophthalmic suspension 0.6% (w/v%) contains benzalkonium chloride (BAK) as a preservative. We evaluated the in vitro time-kill activity of besifloxacin, alone and in combination with BAK, against common bacteria implicated in ophthalmic infections. Methods: The activity of besifloxacin (100 µg/mL), BAK (10, 15, 20, and 100 µg/mL), and combinations of besifloxacin and BAK were evaluated against isolates of Staphylococcus epidermidis (n = 4), Staphylococcus aureus (n = 3), Haemophilus influenzae (n = 2), and Pseudomonas aeruginosa (n = 2) in time-kill experiments of 180 min duration. With the exception of one S. aureus isolate, all of the staphylococcal isolates were methicillin- and/or ciprofloxacin-resistant; one P. aeruginosa isolate was ciprofloxacin-resistant. The reductions in the viable colony counts (log10 CFU/mL) were plotted against time, and the differences among the time–kill curves were evaluated using an analysis of variance. Areas-under-the-killing-curve (AUKCs) were also computed. Results: Besifloxacin alone demonstrated ≥3-log killing of P. aeruginosa (<5 min) and H. influenzae (<120 min), and approached 3-log kills of S. aureus. BAK alone demonstrated concentration-dependent killing of S. epidermidis, S. aureus and H. influenzae, and at 100 µg/mL produced ≥3-log kills in <5 min against these species. The addition of BAK (10, 15, and 20 µg/mL) to besifloxacin increased the rate of killing compared to besifloxacin alone, with earlier 3-log kills of all species except P. aeruginosa and a variable impact on S. aureus. The greatest reductions in AUKC were observed among H. influenzae (8-fold) and S. epidermidis (≥5-fold). Similar results were found when the isolates were evaluated individually by their resistance phenotype. Conclusions: In addition to confirming the activity of 100 µg/mL BAK as a preservative in the bottle, these data suggest that BAK may help besifloxacin to achieve faster time-kills on-eye in the immediate timeframe post-instillation before extensive dilution against bacterial species implicated in ophthalmic infections, including drug-resistant S. epidermidis. Greater killing activity may help prevent resistance development and/or help treat resistant organisms.

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. 

Susceptibility of Propionibacterium acnes, Staphylococcus aureus and Staphylococcus epidermidis to 10 Kampo Formulations

1997 ◽  
Vol 25 (6) ◽  
pp. 318-324 ◽  
Author(s):  
S Higaki ◽  
S Mommatsu ◽  
M Morohashi ◽  
T Yamagishi ◽  
Y Hasegawa
Keyword(s):  
Staphylococcus Aureus ◽  
Staphylococcus Epidermidis ◽  
Propionibacterium Acnes ◽  
Herbal Medicines ◽  
Skin Infections ◽  
Common Cause ◽  
Chinese Herbal ◽  
Crude Drugs ◽  
And Staphylococcus Aureus

We examined the in vitro sensitivities of three bacteria: Propionibacterium acnes, and Staphylococcus epidermidis, commonly detected in acne lesions, and Staphylococcus aureus, a common cause of skin infections, to 10 Kampo formulations (Chinese herbal medicines; combinations of powdered extracts of crude drugs). Both Staphylococcus species showed similar sensitivities to all 10 formulations, with minimum inhibitory concentrations (MICs) ranging from 25 to 400 mg/ml. P. acnes, however, was particularly sensitive to one formulation, keigai-rengyo-to (MIC, 0.78 – 25 mg/ml), prompting speculation that it might contain components with strong antibacterial activity to P. acnes. P. acnes showed similar sensitivities to all the other formulations (MIC 6.25 – 200 mg/ml). The ranges of MICs and the MIC50s (concentrations that inhibit 50% of isolates) were very similar to those previously recorded in 1990 for the two Staphylococcus species.

scholarly journals BIOLOGICAL ACTIVITIES OF NOVEL IN VITRO RAISED STEVIA PLANT

2017 ◽  
Vol 10 (8) ◽  
pp. 240 ◽  
Author(s):  
Neeta Raj Sharma ◽  
Vineet Meshram ◽  
Mahiti Gupta
Keyword(s):  
Pancreatic Lipase ◽  
Staphylococcus Epidermidis ◽  
Inhibitory Activity ◽  
Inhibitory Concentration ◽  
Methanolic Extract ◽  
Biological Activities ◽  
Gram Negative Bacteria ◽  
Herbal Formulation ◽  
Further Development

  Objective: This communication explores a lead fraction from methanolic extract of novel Stevia species raised under in vitro conditions for its various biological activities.Methods: The dried Stevia leaves were crushed in methanol to get the polar extract. This methanol extract was tested for pancreatic lipase and alpha-amylase inhibitory activity using quantitative plate assays. Antibacterial property of the extract was also evaluated against Staphylococcus epidermidis, Escherichia coli, Bacillus subtilis, Staphylococcus aureus, and Pseudomonas aeruginosa. Further, the antioxidant potential was evaluated using 1,1-diphenyl-2-picrylhydrazyl.Results: The methanolic extract inhibited pancreatic lipase with IC50 of 5.74 μg/ml in a similar manner to a well-known anti-obesity drug in the market orlistat. The methanolic extract also showed a better pancreatic α-amylase inhibitory activity (IC50=88 μg/ml) than acarbose. Further, the lead fraction exhibited 88.48% antioxidant activity. It also exhibited broad spectrum antimicrobial activity against the spectrum of Gram-positive and Gram-negative bacteria tested under laboratory conditions with a minimal inhibitory concentration ranging from 1.95 to 31.25 μg/ml.Conclusion: Thus, this study signifies the vast potential of the lead fraction from a novel Stevia species for further development into a herbal formulation for prevention of various infectious and non-infectious diseases.

scholarly journals In Vivo Activity of the Pyrrolopyrazolyl-Substituted Oxazolidinone RWJ-416457

2009 ◽  
Vol 53 (5) ◽  
pp. 2028-2033 ◽  
Author(s):  
Jamese J. Hilliard ◽  
Jeffrey Fernandez ◽  
John Melton ◽  
Mark J. Macielag ◽  
Raul Goldschmidt ◽  
...  
Keyword(s):  
Free Drug ◽  
Lower Respiratory Infection ◽  
Skin Infections ◽  
Pharmacodynamic Parameter ◽  
Routes Of Administration ◽  
Concentration Time ◽  
Infection Models ◽  
Systemic Infections

ABSTRACT RWJ-416457 is an investigational pyrrolopyrazolyl-substituted oxazolidinone with activity against antibiotic-susceptible and -resistant gram-positive pathogens. Efficacies of RWJ-416457, linezolid, and vancomycin against methicillin-susceptible Staphylococcus aureus (MSSA) and community-associated methicillin-resistant S. aureus (CA-MRSA) in murine skin and systemic infections were compared, as were efficacies against Streptococcus pneumoniae in a lower respiratory infection. In staphylococcal systemic infections, RWJ-416457 was equipotent with to twofold more potent than linezolid, with 50% effective dose values ranging from 1.5 to 5 mg/kg of body weight/day. RWJ-416457 was two- to fourfold less potent than vancomycin against MSSA but up to fourfold more potent than vancomycin against CA-MRSA. In MSSA and CA-MRSA skin infections, RWJ-416457 demonstrated an efficacy similar to that of linezolid, reducing CFU/g skin approximately 1.0 log10 at all doses tested; vancomycin yielded greater reductions than the oxazolidinones, with decreases in CFU/g skin of 3 log10 (MSSA) and 2 log10 (CA-MRSA). In the pneumococcal model, RWJ-416457 was two- to fourfold more potent than linezolid. The free-drug area under the concentration-time curves at 24 h (fAUC24) were similar for RWJ-416457 and linezolid. The half-life of RWJ-416457 was up to threefold longer than that of linezolid for all routes of administration. The fAUC24/MIC ratio, the pharmacodynamic parameter considered predictive of oxazolidinone efficacy, was approximately twofold greater for RWJ-416457 than for linezolid. Since the fAUC values were similar for both compounds, the higher fAUC/MIC ratios of RWJ-416457 appear to result from its greater in vitro potency. These results demonstrate that RWJ-416457 is a promising new oxazolidinone with efficacy in S. aureus or S. pneumoniae mouse infection models.

scholarly journals Evaluation in vitro of antimicrobial activity of tucumã oil (Astrocaryum Vulgare)

2019 ◽  
Vol 1 (1) ◽  
pp. 99-112 ◽  
Author(s):  
Aline Rossato ◽  
Larissa da Silva Silveira ◽  
Leonardo Quintana Soares Lopes ◽  
Walter Paixão De Sousa Filho ◽  
Larissa Finger Schaffer ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Staphylococcus Epidermidis ◽  
Inhibitory Concentration ◽  
Major Health Problem ◽  
Major Health ◽  
Gram Positive Bacteria ◽  
Palm Trees ◽  
The Family

Hospital Infection is a major health problem and affects around 1.5 million people annually around the world. The Amazon region has a wide diversity of native palm trees that have fruits and oilseeds. Astrocaryum vulgare, commonly known as Tucumã in Brazil, belongs to the family Arecaceae. This palm has orange, fleshy, single-egg-shaped fruits that are used for therapeutic purposes in diseases of the eyes and skin due to the high content of carotenoids, oil is used in cooking, health treatment and massage. This study evaluated the antimicrobial activity of the Tucumã oil against 18 microorganisms. The antimicrobial activity of Tucumã was measured through the determination of the Minimum Inhibitory Concentration (MIC), as well as the determination of the Minimum Microbicidal Concentration (CMM) aiming to contribute to the discovery of new antimicrobials against pathogenic microorganisms’ human health and may contribute to the treatment of nosocomial infections. The results showed that the oil of Tucumã presented antimicrobial activity against five important bacteria, four Gram - positive bacteria (Enterococcus faecalis, Enterococcus faecium, Staphylococcus epidermidis and Streptococcus agalactiae) and one Gram - negative (Acinetobacter baumannii).

In Vitro Effect of Multiple Antibiotic/Antimicrobial Residues on the Selection for Resistance in Bacteria

1992 ◽  
Vol 75 (4) ◽  
pp. 738-741 ◽  
Author(s):  
Marietta Sue Brady ◽  
Stanley E Katz
Keyword(s):  
Inhibitory Concentration ◽  
Enterobacter Cloacae ◽  
Cross Resistance ◽  
Resistance Development ◽  
Gram Negative ◽  
Antimicrobial Residues ◽  
Residue Levels ◽  
Selection For ◽  
Vitro Effect

Abstract A method using a gram-positive and a gram-negative organism was used to investigate the selection for resistant populations after exposure to residue levels of 7 antibiotics and 1 antimicrobial. The organisms were exposed to individual compounds and combinations of 3 compounds for 14 days. The changes in minimum inhibitory concentration (MIC) of a panel of 8 antibiotics and 1 antimicrobial were used as the measure of resistance development/selection. For Staphylococcus aureus ATCC 9144, exposure to residue levels of oxytetracycline, tylosin, penicillin, and virginiamycin resulted in an increased MIC of the compound itself; most individual residues did not result in increased cross-resistance. With combinations of residues, 13 of 45 determinations resulted in significant increases in MIC. Enterobacter cloacae B520, which was much less sensitive to 4 of 9 markers, showed MIC increases only for tylosin and the combination of neomycin-sulfamethazine-oxytetracycline. The results indicate an interaction among residue levels of antibiotics in selection for resistance.

Activity of Nadifloxacin against Methicillin-Resistant Staphylococcus aureus Isolated from Skin Infections: Comparative Study with Seven other Fluoroquinolones

1996 ◽  
Vol 24 (1) ◽  
pp. 12-16 ◽  
Author(s):  
S Nishijima ◽  
M Nakagawa ◽  
N Tsuboi ◽  
H Akamatsu ◽  
T Horio ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Minimum Inhibitory Concentration ◽  
Comparative Study ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Inhibitory Concentration ◽  
The Other ◽  
Skin Infections ◽  
In Vitro Susceptibility ◽  
Methicillin Resistant

The in vitro susceptibility of methicillin-resistant Staphylococcus aureus(MRSA) to nadifloxacin and seven other fluoroquinolones (norfloxacin, ofloxacin, enoxacin, ciprofloxacin, lomefloxacin, tosufloxacin and sparfloxacin) was evaluated. The MRSA isolates were isolated from 114 skin infections between 1991 and 1994. Nadifloxacin exhibited the lowest minimum inhibitory concentration and there were no MRSA isolates resistant to nadifloxacin, while there were some resistant to all of the other seven fluoroquinolones. The minimum concentrations of these drugs needed to cause 50% inhibition of the isolates increased dramatically from 1991 to 1992, but has hardly changed since 1992.

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 A simple, fast and reliable scan-based technique as a novel approach to quantify intracellular bacteria

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Meysam Sarshar ◽  
Daniela Scribano ◽  
Giulia Tranquilli ◽  
Marisa Di Pietro ◽  
Simone Filardo ◽  
...  
Keyword(s):  
High Throughput Screening ◽  
High Speed ◽  
Low Cost ◽  
Shigella Flexneri ◽  
Intracellular Bacteria ◽  
Fluorescence Signal ◽  
Chronic Infections ◽  
Novel Approach ◽  
Infection Models

Abstract Background Quantification of intracellular bacteria is fundamental in many areas of cellular and clinical microbiology to study acute and chronic infections. Therefore, rapid, accurate and low-cost methods represent valuable tools in determining bacterial ability to persist and proliferate within eukaryotic cells. Results Herein, we present the first application of the immunofluorescence In-Cell Western (ICW) assay aimed at quantifying intracellular bacteria in in vitro infection models. The performance of this new approach was evaluated in cell culture infection models using three microorganisms with different lifestyles. Two facultative intracellular bacteria, the fast-growing Shigella flexneri and a persistent strain of Escherichia coli, as well as the obligate intracellular bacterium Chlamydia trachomatis were chosen as bacterial models. The ICW assay was performed in parallel with conventional quantification methods, i.e. colony forming units (CFUs) and inclusion forming units (IFUs). The fluorescence signal intensity values from the ICW assay were highly correlated to CFU/IFUs counting and showed coefficients of determination (R2), ranging from 0,92 to 0,99. Conclusions The ICW assay offers several advantages including sensitivity, reproducibility, high speed, operator-independent data acquisition and overtime stability of fluorescence signals. All these features, together with the simplicity in performance, make this assay particularly suitable for high-throughput screening and diagnostic approaches.

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