scholarly journals Influence of biofilm growth age, media, antibiotic concentration and exposure time on Staphylococcus aureus and Pseudomonas aeruginosa biofilm removal in vitro

2020 ◽  
Author(s):  
Xiaofeng Chen ◽  
Trine Rolighed Thomsen ◽  
Heinz Winkler ◽  
Yijuan Xu
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Treatment Duration ◽  
Time Dependent ◽  
Growth Media ◽  
Antibiotic Concentration ◽  
Biofilm Growth ◽  
Biofilm Removal ◽  
Experimental Parameters

Abstract Background: Biofilm is known to be tolerant towards antibiotics and difficult to eradicate. Numerous studies have reported minimum biofilm eradication concentration (MBEC) values of antibiotics for many known biofilm pathogens. However, the experimental parameters applied in these studies differ considerably, and often the rationale behind the experimental design are not well described. This makes it difficult to compare the findings. To demonstrate the importance of experimental parameters, we investigated the influence of biofilm growth age, antibiotic concentration and treatment duration, and growth media on biofilm eradication. Additionally, OSTEOmycinTM, a clinically used antibiotic containing allograft bone product, was tested for antibiofilm efficacy. Results: The commonly used Calgary biofilm device was used to grow 24 h and 72 h biofilms of Staphylococcus aureus and Pseudomonas aeruginosa, which were treated with time-dependent vancomycin (up to 3000 mg L-1) and concentration-dependent tobramycin (up to 80 mg L-1), respectively. Two common bacteriological growth media tryptic soy broth (TSB) and cation-adjusted Mueller Hinton broth (CaMHB) were tested. We found for both species that biofilms were more difficult to kill in TSB than in CaMHB. Furthermore, young biofilms (24 h) were easier to eradicate than old biofilms (72 h). In agreement with vancomycin being time-dependent, extension of the vancomycin exposure increased killing of S. aureus biofilms. Tobramycin treatment of 24 h P. aeruginosa biofilms was found concentration-dependent and time-independent, however, increasing killing was indicated for 72 h P. aeruginosa biofilms. Treatment with tobramycin containing OSTEOmycin TTM removed 72 h and 168 h P. aeruginosa biofilms after one day treatment, while few 72h S. aureus biofilms survived after two days treatment with vancomycin containing OSTEOmycin VTM. Conclusions: This study demonstrated biofilm removal efficacy was influenced by media, biofilm age and antibiotic concentration and treatment duration. It is therefore necessary to taking these parameters into consideration when designing experiments. The results of OSTEOmycinTM products indicated that simple in vitro biofilm test could be used for initial screening of antibiofilm products. For clinical application, a more clinically relevant biofilm model for the specific biofilm infection in question should be developed to guide the amount of antibiotics used for local antibiofilm treatment.

scholarly journals Influence of biofilm growth age, media, antibiotic concentration and exposure time on Staphylococcus aureus and Pseudomonas aeruginosa biofilm removal in vitro

2020 ◽  
Author(s):  
Xiaofeng Chen ◽  
Trine Rolighed Thomsen ◽  
Heinz Winkler ◽  
Yijuan Xu
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Treatment Duration ◽  
Time Dependent ◽  
Growth Media ◽  
Antibiotic Concentration ◽  
Biofilm Growth ◽  
Biofilm Removal ◽  
Experimental Parameters

Abstract Background: Biofilm is known to be tolerant towards antibiotics and difficult to eradicate. Numerous studies have reported Minimum Biofilm Eradication Concentration (MBEC) values of antibiotics for many known biofilm pathogens. However, the experimental parameters applied in these studies differ considerably, and often the rationale behind the experimental design are not well described. This makes it difficult to compare the findings. To demonstrate the importance of experimental parameters, we investigated the influence of biofilm growth age, antibiotic concentration and treatment duration, and growth media on biofilm eradication. Additionally, OSTEOmycinTM, a clinically used antibiotic containing allograft bone product, was tested for antibiofilm efficacy. Results: The commonly used Calgary biofilm device was used to grow 24 h and 72 h biofilms of Staphylococcus aureus and Pseudomonas aeruginosa, which were treated with time-dependent vancomycin (up to 3000 mg/L) and concentration-dependent tobramycin (up to 80 mg/L), respectively. Two common bacteriological growth media Tryptic Soy Broth (TSB) and Cation-adjusted Mueller Hinton Broth (CaMHB) were tested. We found for both species that biofilms were more difficult to kill in TSB than in CaMHB. Furthermore, young biofilms (24 h) were easier to eradicate than old biofilms (72 h). In agreement with vancomycin being time-dependent, extension of the vancomycin exposure increased killing of S. aureus biofilms. Tobramycin treatment of 24 h P. aeruginosa biofilms was found concentration-dependent and time-independent, however, increasing killing was indicated for 72 h P. aeruginosa biofilms. Treatment with tobramycin containing OSTEOmycin TTM removed 72 h and 168 h P. aeruginosa biofilms after one day treatment, while few 72h S. aureus biofilms survived after two days treatment with vancomycin containing OSTEOmycin VTM. Conclusions: This study demonstrated biofilm removal efficacy was influenced by media, biofilm age and antibiotic concentration and treatment duration. It is therefore necessary to taking these parameters into consideration when designing experiments. The results of OSTEOmycin products indicated that simple in vitro biofilm test could be used for initial screening of antibiofilm products. For clinical application, a more clinically relevant biofilm model for the specific biofilm infection in question should be developed to guide the amount of antibiotics used for local antibiofilm treatment.

scholarly journals Influence of biofilm growth age, media and antibiotics exposure time on Staphylococcus aureus and Pseudomonas aeruginosa biofilm removal in vitro

2020 ◽  
Author(s):  
Xiaofeng Chen ◽  
Yijuan Xu ◽  
Heinz Winkler ◽  
Trine Rolighed Thomsen
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Treatment Duration ◽  
Time Dependent ◽  
Growth Media ◽  
Biofilm Growth ◽  
Biofilm Removal ◽  
Mueller Hinton ◽  
Experimental Parameters

Abstract Biofilm is known to be tolerant towards antibiotics and difficult to eradicate. Numerous studies have reported Minimum Biofilm Eradication Concentration (MBEC) values of antibiotics for many known biofilm pathogens. However, the experimental parameters applied in these studies differ considerably, and often the rationale behind the experimental design are not well described. This makes it difficult to compare the findings. To demonstrate the importance of experimental parameters, we investigated the influence of biofilm growth age, antibiotic treatment duration and growth media on biofilm eradication in this study. The commonly used biofilm model Calgary biofilm device was used to grow 24 h and 72 h biofilms of Staphylococcus aureus and Pseudomonas aeruginosa , which were treated with time-dependent vancomycin and concentration-dependent tobramycin, respectively. Two common bacteriological growth media Tryptic Soy Broth (TSB) and Cation-adjusted Mueller Hinton Broth (CaMHB) were tested. We found for both species that biofilms were more difficult to kill in TSB than in CaMHB. Furthermore, young biofilms (24 h) were easier to eradicate than old biofilms (72 h). In agreement with vancomycin being time-dependent, extension of the vancomycin exposure increased killing of S. aureus biofilms. Tobramycin treatment of 24 h P. aeruginosa biofilms was found concentration-dependent and time-independent, however, increasing killing was indicated for 72 h P. aeruginosa biofilms. This study demonstrated biofilm removal efficacy was influenced by media, biofilm age and antibiotics treatment duration. It is therefore necessary to taking these parameters into consideration when designing experiments.

Exploration of the Pharmacodynamics for Pseudomonas aeruginosa Biofilm Eradication by Tobramycin

2021 ◽  
Author(s):  
Devin Sindeldecker ◽  
Shaurya Prakash ◽  
Paul Stoodley
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Drug Resistance ◽  
Treatment Duration ◽  
Area Under The Curve ◽  
Opportunistic Pathogen ◽  
Multi Drug Resistance ◽  
Antibiotic Concentration ◽  
Antibiotic Resistant ◽  
Gram Negative

Pseudomonas aeruginosa is a Gram-negative, opportunistic pathogen which is involved in numerous infections. It is of growing concern within the field of antibiotic resistant and tolerance and often exhibits multi-drug resistance. Previous studies have shown the emergence of antibiotic resistant and tolerant variants within the zone of clearance of a biofilm lawn after exposure to aminoglycosides. As concerning as the tolerant variant emergence is, there was also a zone of killing (ZOK) immediately surrounding the antibiotic source from which no detectable bacteria emerged or were cultured. In this study, the ZOK was analyzed using both in vitro and in silico methods to determine if there was a consistent antibiotic concentration versus time constraint (area under the curve, (AUC)) which is able to completely kill all bacteria in the lawn biofilms in our in vitro model. Our studies revealed that by achieving an average AUC of 4,372.5 μg*hr/mL, complete eradication of biofilms grown on both agar and hydroxyapatite was possible. These findings show that appropriate antibiotic concentrations and treatment duration may be able to treat antibiotic resistant and tolerant biofilm infections.

scholarly journals Increased rates of genomic mutation in a biofilm co-culture model of Pseudomonas aeruginosa and Staphylococcus aureus

2018 ◽  
Author(s):  
C.J. Frapwell ◽  
R.P. Howlin ◽  
O. Soren ◽  
B.T. McDonagh ◽  
C.M. Duignan ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Mutation Rates ◽  
Interspecies Interactions ◽  
Short Term ◽  
Biofilm Growth ◽  
Biofilm Model ◽  
Adaptive Processes ◽  
Cystic Fibrosis Isolate

AbstractBiofilms are major contributors to disease chronicity and are typically multi-species in nature. Pseudomonas aeruginosa and Staphylococcus aureus are leading causes of morbidity and mortality in a variety of chronic diseases but current in vitro dual-species biofilms models involving these pathogens are limited by short co-culture times (24 to 48 hours). Here, we describe the establishment of a stable (240 hour) co-culture biofilm model of P. aeruginosa and S. aureus that is reproducible and more representative of chronic disease.The ability of two P. aeruginosa strains, (PAO1 and a cystic fibrosis isolate, PA21), to form co-culture biofilms with S. aureus was investigated. Co-culture was stable for longer periods using P. aeruginosa PA21 and S. aureus viability within the model improved in the presence of exogenous hemin. Biofilm co-culture was associated with increased tolerance of P. aeruginosa to tobramycin and increased susceptibility of S. aureus to tobramycin and a novel antimicrobial, HT61, previously shown to be more effective against non-dividing cultures of Staphylococcal spp. Biofilm growth was also associated with increased short-term mutation rates; 10-fold for P. aeruginosa and 500-fold for S. aureus.By describing a reproducible 240 hour co-culture biofilm model of P. aeruginosa and S. aureus, we have shown that interspecies interactions between these organisms may influence short-term mutation rates and evolution, which could be of importance in understanding the adaptive processes that lead to the development of antimicrobial resistance.

scholarly journals Aminoglycoside inhibition of Staphylococcus aureus biofilm formation is nutrient dependent

2014 ◽  
Vol 63 (6) ◽  
pp. 861-869 ◽  
Author(s):  
Michelle J. Henry-Stanley ◽  
Donavon J. Hess ◽  
Carol L. Wells
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Growth Medium ◽  
Antibiotic Susceptibility ◽  
Biofilm Formation ◽  
Nutrient Concentration ◽  
Growth Media ◽  
Biofilm Growth

Biofilms represent microbial communities, encased in a self-produced matrix or extracellular polymeric substance. Microbial biofilms are likely responsible for a large proportion of clinically significant infections and the multicellular nature of biofilm existence has been repeatedly associated with antibiotic resistance. Classical in vitro antibiotic-susceptibility testing utilizes artificial growth media and planktonic microbes, but this method may not account for the variability inherent in environments subject to biofilm growth in vivo. Experiments were designed to test the hypothesis that nutrient concentration can modulate the antibiotic susceptibility of Staphylococcus aureus biofilms. Developing S. aureus biofilms initiated on surgical sutures, and in selected experiments planktonic cultures, were incubated for 16 h in 66 % tryptic soy broth, 0.2 % glucose (1× TSBg), supplemented with bactericidal concentrations of gentamicin, streptomycin, ampicillin or vancomycin. In parallel experiments, antibiotics were added to growth medium diluted one-third (1/3× TSBg) or concentrated threefold (3× TSBg). Following incubation, viable bacteria were enumerated from planktonic cultures or suture sonicates, and biofilm biomass was assayed using spectrophotometry. Interestingly, bactericidal concentrations of gentamicin (5 µg gentamicin ml−1) and streptomycin (32 µg streptomycin ml−1) inhibited biofilm formation in samples incubated in 1/3× or 1× TSBg, but not in samples incubated in 3× TSBg. The nutrient dependence of aminoglycoside susceptibility is not only associated with biofilm formation, as planktonic cultures incubated in 3× TSBg in the presence of gentamicin also showed antibiotic resistance. These findings appeared specific for aminoglycosides because biofilm formation was inhibited in all three growth media supplemented with bactericidal concentrations of the cell wall-active antibiotics, ampicillin and vancomycin. Additional experiments showed that the ability of 3× TSBg to overcome the antibacterial effects of gentamicin was associated with decreased uptake of gentamicin by S. aureus. Uptake is known to be decreased at low pH, and the kinetic change in pH of growth medium from biofilms incubated in 5 µg gentamicin ml−1 in the presence of 3× TSBg was decreased when compared with pH determinations from biofilms formed in 1/3× or 1× TSBg. These studies underscore the importance of environmental factors, including nutrient concentration and pH, on the antibiotic susceptibility of S. aureus planktonic and biofilm bacteria.

ATIVIDADE ANTIMICROBIANA IN VITRO DO EXTRATO AQUOSO, HIDROALCOÓLICO E ALCOÓLICO DE FOLHAS DE ESPÉCIES DA FAMÍLIA LAMIACEAE

2018 ◽  
Vol 4 ◽  
Author(s):  
Karlynne Freire Mendonça ◽  
José Klauber Roger Carneiro ◽  
Maria Auxiliadora Silva Oliveira
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Enterococcus Faecalis ◽  
Streptococcus Pyogenes ◽  
Mentha Arvensis ◽  
Ocimum Gratissimum ◽  
Mueller Hinton ◽  
Plectranthus Amboinicus

Objetivos: avaliar a atividade antimicrobiana em extrato aquoso, hidroalcoólico e alcoólico das folhas de espécies da família Lamiaceae frente a bactérias de interesse. Método: Foram escolhidas quatro espécies: Ocimum gratissimum, Plectranthus amboinicus, Mentha arvensis e Plectranthus barbatus. A partir das folhas foram confeccionados os extratos aquoso, hidroalcoólico e alcoólico nas concentrações 100mg/mL, 50mg/mL e 25mg/mL. Foram selecionadas as bactérias Streptococcus pyogenes, Enterococcus faecalis, Staphylococcus aureus e Pseudomonas aeruginosa para os ensaios de antibiose em Ágar Mueller-Hinton. Resultados: P. barbatus, em seu extrato hidroalcoólico mostrou ativo nas três concentrações para bactéria S. aureus, e ainda foi ativo para P. aeruginosa, demonstrando no extrato alcoólico atividade frente as bactérias. Para M. arvensis e P. amboinicus, seus extratos hidroalcoólico e alcoólico apresentaram atividade para S. aureus. Conclusão: Sugere-se que as espécies em questão apresentem boa atividade antimicrobiana, sendo necessária a realização de mais estudos para melhor entender esse mecanismo.

Activité antibactérienne de l’huile essentielle de Pelargonium x asperum et son potentiel synergique avec la nisine

2019 ◽  
Vol 17 (3) ◽  
pp. 140-148 ◽  
Author(s):  
A. Ouelhadj ◽  
L. Ait Salem ◽  
D. Djenane
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Klebsiella Pneumoniae ◽  
Nous Avons ◽  
Activité Antibactérienne

Ce travail vise l’étude de l’activité antibactérienne de l’huile essentielle (HE) de Pelargoniumx asperum et de la bactériocine, la nisine seul et en combinaison vis-à-vis de six bactéries dont quatre sont multirésistantes d’origine clinique. L’activité antibactérienne in vitro a été évaluée par la méthode de diffusion sur gélose. La concentration minimale inhibitrice (CMI) est aussi déterminée pour HE. Les résultats ont révélé une activité antibactérienne significative exercée par HE visà-vis de Staphylococcus aureus (ATCC 43300), Staphylococcus aureus et Escherichia coli avec des diamètres d’inhibition de 36,00 ; 22,50 et 40,00 mm, respectivement. Cependant, l’HE de Pelargonium asperum a montré une activité antibactérienne supérieure par rapport à la nisine. Les valeurs des CMI rapportées dans cette étude sont comprises entre 1,98–3,96 μl/ml. Les combinaisons réalisées entre HE et la nisine ont montré un effet additif vis-à-vis de Escherichia coli (ATCC 25922) avec (50 % HE Pelargonium asperum + 50 % nisine). Par contre, nous avons enregistré une synergie vis-à-vis de Klebsiella pneumoniae avec (75 % HE Pelargonium asperum + 25 % nisine) et contre Pseudomonas aeruginosa avec les trois combinaisons testées. Les résultats obtenus permettent de dire que l’HE de Pelargonium asperum possède une activité antibactérienne ainsi que sa combinaison avec la nisine pourrait représenter une bonne alternative pour la lutte contre l’antibiorésistance.

Exploración de la actividad antibacteriana de Metformina frente a Escherichia coli, Staphylococcus aureus y Pseudomonas aeruginosa

Bionatura ◽  
2020 ◽  
Vol 5 (4) ◽  
pp. 1335-1339
Author(s):  
Pool Marcos-Carbajal ◽  
Christian Allca-Muñoz ◽  
Ángel Urbano-Niño ◽  
Alberto Salazar-Granara
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa

El objetivo del estudio es determinar la actividad antibacteriana de Metformina frente a Escherichia coli, Staphylococcus aureus y Pseudomonas aeruginosa. Se evaluó la actividad antibacteriana mediante la técnica de Kirby Bauer. Se utilizó cepas de Escherichia coli (ATCC 25922), Staphylococcus aureus (ATCC 25923) y Pseudomonas aeruginosa (ATCC 27853), las cuales se expusieron a Metformina en concentraciones de 250 mg y 500 mg, Ciprofloxacino (CIP) 5 µg, Imipenem (IPM) 10 µg, y Cefoxitin (FOX) 30 µg. Frente a Escherichia coli, Staphylococcus aureus y Pseudomonas aeruginosa se presentó un halo de inhibición de 6 mm. para Metformina 250 mg, 6 mm. para Metformina 500 mg, y un halo de inhibición >25 mm. con el uso de Ciprofloxacino 5 µg, Cefoxitin 30 µg, e Imipenem 10 µg respectivamente. En conclusion, In vitro Metformina a dosis de 250 y 500 mg, no presentó efecto antibacteriano frente a Escherichia coli, Staphylococcus aureus y Pseudomonas aeruginosa.

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