Guide for Assessment of Antimicrobial Activity Using a Time-Kill Procedure

2008 ◽  
Author(s):  
Keyword(s):  
Antimicrobial Activity ◽  
Time Kill

scholarly journals Essential oils as potential anti-staphylococcal agents

2018 ◽  
Vol 68 (1) ◽  
pp. 95-107 ◽  
Author(s):  
Szweda Piotr ◽  
Zalewska Magdalena ◽  
Pilch Joanna ◽  
Kot Barbara ◽  
Milewski Sławomir
Keyword(s):  
Antimicrobial Activity ◽  
Essential Oils ◽  
Bovine Mastitis ◽  
Bactericidal Effect ◽  
Dilution Method ◽  
Kinetic Assay ◽  
Cinnamon Oil ◽  
Microtiter Plates ◽  
Cure Rates ◽  
Time Kill

Abstract Antibiotic therapy of staphylococcal mastitis is characterized by significantly lower cure rates compared to infections caused by other microorganisms. Thus, it is necessary to search for new, alternative, non-antibiotic agents that are effective in the eradication of these bacteria. The aim of our research was to investigate the antimicrobial, especially anti-staphylococcal potential of a large collection (n=36) of essential oils (EOs). Investigation of the antimicrobial activity of tested oils was determined by using a serial, twofold dilution method in 96-wells microtiter plates under conditions recommended by the Clinical and Laboratory Standards Institute (CLSI). The preliminary analysis revealed that six oils, namely: Manuka, Thyme, Geranium, Cedar, Cinnamon (from bark) and Patchouli exhibited the highest activity against reference strains of bacteria. Significant anti-staphylococcal potential of these oils has been also confirmed for a group of 18 Staphylococcus aureus, 8 Staphylococcus epidermidis and 5 Staphylococcus xylosus strains isolated from cases of bovine mastitis. Especially high activity was observed for Cedar, Patchouli, Thyme and Manuka oils. The MIC (Minimal Inhibitory Concentration) values for Patchouli oil were in the concentrations range of 0.01 to 0.313% (v/v). The three other oils inhibited the growth of staphylococci isolated from mastitis in the concentrations range of 0.01 to 0.625% (v/v). Oils isolated from Cinnamomum cassia and Pelargonium graveolens revealed a bit lower, but still satisfactory activity (MIC values in the concentrations range of 0.02 to 1.25% (v/v) and from 0.078 to 1.25% (v/v), respectively). In many cases a slightly higher concentration of oils was required to obtain the bactericidal effect in comparison to growth inhibition. The time – kill kinetic assay revealed that the bactericidal effect was achieved after two hours incubation of the reference strain S. aureus PCM 2051 cells with Thyme oil at concentration equal to 2xMIC (1.25% (v/v)) or MIC (0.625% (v/v)). A slightly lower activity was observed in the case of Cinnamon oil, the bactericidal effect was achieved after 8 hours of incubation. The results of our research clearly indicate that some essential oils exhibit a promising antimicrobial activity and can be considered as alternative antistaphylococcal agents.

scholarly journals Antimicrobial activity and time kill kinetics of Nigerian Honeys on multi-resistant Enteric Bacilli

2018 ◽  
Vol 210 ◽  
pp. 012003
Author(s):  
P.A Akinduti ◽  
A Oluwadun ◽  
J.A.O Olugbuyiro ◽  
C.S Osuagwu ◽  
O Ejilude ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Time Kill ◽  
Kinetics Of

scholarly journals Antimicrobial Activity of Wine in Relation to Bacterial Resistance to Medicinal Antibiotics

OENO One ◽  
2021 ◽  
Vol 55 (1) ◽  
pp. 45-48
Author(s):  
Mladen Boban ◽  
Nataša Boban ◽  
Marija Tonkić ◽  
Mia Grga ◽  
Ana Marija Milat ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Activity ◽  
Salmonella Enteritidis ◽  
Bacterial Resistance ◽  
Bacterial Suspension ◽  
Antimicrobial Drugs ◽  
Principal Mechanism ◽  
E Coli ◽  
Resistance To Antibiotics ◽  
Time Kill

Although antimicrobial properties of wine have been extensively studied, antimicrobial effects of wine in relation to bacterial resistance to medicinal antibiotics have not been examined. Therefore, our aim was to determine whether bacterial resistance to antibiotics can be related to their resistance to red wine as an unspecific antimicrobial medium. The organisms studied were Salmonella enteritidis (ATCC 13076), Escherichia coli (ATCC 25922), and two clinical isolates which exhibited different resistance to antibiotics, ESBL - producing Escherichia coli UR 3612 and Salmonella enteritidis KK 962. The time-kill curves method was used. The minimal incubation time of the bacterial suspension with wine, necessary for prevention of bacterial growth, was 3 and 20 min for E. coli ATCC and ESBL E. coli respectively. This was associated with susceptibility testing in which E. coli ATCC proved highly sensitive in contrast to ESBL-producing E. coli, which exhibited resistance to a spectrum of antimicrobial drugs of different classes regarding their principal mechanism of action. In the case of S. enteritidis strains, they were similar in their susceptibility against test antibiotics and time-kill curves following exposure to wine. Bacterial resistance to wine is closely associated with bacterial resistance to antimicrobial drugs. The exact mechanisms of antimicrobial activity of wine are still a matter of debate. However, wine might be less susceptible to bacterial resistance development and may include mechanisms different from those of medicinal antibiotics. The present study represents an initial contribution to this important subject which has been practically unexplored.

scholarly journals Antimicrobial Activity of Ceftriaxone Compared with Cefotaxime in the Presence of Serum Albumin

1995 ◽  
Vol 6 (1) ◽  
pp. 21-27 ◽  
Author(s):  
Swapan K Nath ◽  
Gary A Foster ◽  
Lionel A Mandell ◽  
Coleman Rotstein
Keyword(s):  
Antimicrobial Activity ◽  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Significant Interaction ◽  
Gram Negative ◽  
In Vitro Antimicrobial Activity ◽  
Bactericidal Activities ◽  
Time Kill

The effect of serum albumin on the antimicrobial activity of ceftriaxone, cefotaxime, and a 1:1 ratio of cefotaxime and its desacetyl metabolite against nonpseudomonal Gram-negative bacilli was determined. Antimicrobial activity of drugs was evaluated by measuring minimum inhibitory (mic) and bactericidal (mbc) concentrations in broth with and without human serum albumin. The analysis of logarithmically transformed meanmics andmbcs showed that there was a highly significant interaction between drug and serum albumin (P<0.0001). The inhibitory and bactericidal activities were greatest for cefotaxime followed by cefotaxime/desacetylcefotaxime and ceftriaxone (P<0.01). Time-kill kinetics demonstrated that ceftriaxone was less bactericidal than cefotaxime in broth with albumin. On the basis of these results it was concluded that the in vitro antimicrobial activity of ceftriaxone compared with that of cefotaxime was significantly diminished in the presence of serum albumin.

scholarly journals Effect of Pulmonary Surfactant on Antimicrobial ActivityIn Vitro

2013 ◽  
Vol 57 (10) ◽  
pp. 5151-5154 ◽  
Author(s):  
R. Schwameis ◽  
Z. Erdogan-Yildirim ◽  
M. Manafi ◽  
M. A. Zeitlinger ◽  
S. Strommer ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Respiratory Tract ◽  
Pulmonary Surfactant ◽  
Respiratory Tract Infections ◽  
Content Type ◽  
Kill Curve ◽  
Tract Infections ◽  
Time Kill

ABSTRACTTime-kill curve experiments were performed with linezolid, doripenem, tigecycline, moxifloxacin, and daptomycin againstStaphylococcus aureusand with colistin, moxifloxacin, and doripenem againstPseudomonas aeruginosato evaluate the effect of porcine pulmonary surfactant on antimicrobial activity. Pulmonary surfactant significantly impaired the activities of moxifloxacin and colistin. When antibiotics are being developed for respiratory tract infections, the method described here might be used to preliminarily quantify the effect of pulmonary surfactant on antimicrobial activity.

scholarly journals Efficacy of Biofilm Disrupters Against Candida auris and Other Candida species

2020 ◽  
Author(s):  
Claudia A Cox ◽  
Jose A Vazquez ◽  
Sushama Wakade ◽  
Marek Bogacz ◽  
Matthew Myntti ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Chronic Wounds ◽  
Inhibition Zone ◽  
Novel Agents ◽  
Dependent Manner ◽  
Candida Auris ◽  
Candida Spp ◽  
Concentration Dependent Manner ◽  
Environmental Surfaces ◽  
Time Kill

ABSTRACTBackgroundC. auris has become a globally emerging fungal pathogen, frequently reported to be multi-drug resistant, commonly found with Staphylococcus aureus in polymicrobial nosocomial infections. Although chlorhexidine (CHD) has been shown to be effective, it is associated with serious anaphylaxis reactions. Biofilm disrupters (BDs) are novel agents with a broad spectrum of antimicrobial activity. BDs have been used in the management of chronic wounds and to sterilize environmental surfaces. The goal of this study was to evaluate BDs against polymicrobial biofilms compared to CHD.MethodologyWe evaluated various BDs (BlastX, Torrent, NSSD) and CHD against Candida spp and S. aureus polymicrobial biofilms by zone of inhibition, biofilm, and time-kill assays. Effectiveness was based on the inhibition zone and the reduction of CFU, respectively, compared to the drug-free control.ResultsAll BDs and CHD inhibited C. auris growth effectively in a concentration-dependent manner. Additionally, CHD and the BDs all showed excellent antimicrobial activity against polymicrobial biofilms. BDs were all highly effective against both C. auris isolates, whereas CHD was only moderately effective against C. auris 0386, suggesting resistance/tolerance. A comparative analysis of the BDs and CHD against C. auris and C. albicans by biofilm kill-curves showed at least 99.999% killing.ConclusionsAll three BDs and CHD have excellent activity against different Candida species, including C. auris. However, certain isolates of C. auris showed resistance/tolerance to CHD, but not to the BDs. The fungicidal activity of these novel agents will be valuable in eradicating surface colonization of Candida spp, including C. auris.

scholarly journals Whether Supercritical Extracts from the Aerial Parts of Helianthus salicifolius and Helianthus tuberosus May be Regarded as a Potential Raw Materials for Non-bioenergy Purposes?

2020 ◽  
Author(s):  
Anna Malm ◽  
Agnieszka Grzegorczyk ◽  
Anna Biernasiuk ◽  
Tomasz Baj ◽  
Edward Rój ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Raw Materials ◽  
Bactericidal Effect ◽  
Helianthus Tuberosus ◽  
Candida Spp ◽  
Minimum Fungicidal Concentration ◽  
Aerial Parts ◽  
Antistaphylococcal Activity ◽  
Time Kill

The extracts from the aerial parts of Helianthus salicifolius A. Dietr and Helianthus tuberosus L. collected in June were obtained using carbon dioxide supercritical fluid extraction with water as co-solvent. The antimicrobial activity in vitro of these extracts were determined against the reference species of Gram-positive and Gram-negative bacteria as well as fungi, representing by the yeast species of Candida spp. The following parameters were estimated: minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) or minimum fungicidal concentration (MFC). Both extracts were found to possess antimicrobial activity with MIC = 0.62-5 mg mL-1 for bacteria and MIC = 5-10 mg mL-1 for yeasts, showing bactericidal (MBC/MIC = 2-4) or fungicidal effect (MFC/MIC = 1-2 ). The highest activity was observed against S. aureus ATCC 29213 (MIC = 0.62 mg mL-1 for H. salicifolius extract; MIC = 2.5 mg mL-1 for H. tuberosus extract). Bactericidal effect of both extracts against S. aureus ATCC 29213 was confirmed by time-kill assay. Higher antioxidant activity was found for H. tuberosus extract (EC50 = 0.332 mg mL-1) as compared to that of H. salicifolius (EC50 = 0.609 mg mL-1). The total polyphenol content (TPC) expressed as gallic acid equivalents (GAE) was 13.75 &plusmn; 0.50 mg GAE (g of H. salicifolius extract)-1 and 33.06 &plusmn; 0.80 mg GAE (g of H. tuberosus extract)-1. There was a correlation between the antioxidant potential of both extracts and TPC but not between antistaphylococcal activity and TPC. The obtained data suggest potential application of these extracts as the natural preparations with the biocidal activity, including those with antistaphylococcal activity. Besides, both extracts may be regarded as potential natural conservants in cosmetics as well as natural preservatives in food.

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