Verapamil-Tobramycin Synergy in Pseudomonas cepacia but Not Pseudomonas aeruginosa in vitro

Chemotherapy ◽  
1995 ◽  
Vol 41 (5) ◽  
pp. 330-333 ◽  
Author(s):  
Robert C. Cohn ◽  
Lois Rudzienski ◽  
Robert W. Putnam
1995 ◽  
Vol 39 (4) ◽  
pp. 850-853 ◽  
Author(s):  
G M Eliopoulos ◽  
C B Wennersten ◽  
G Cole ◽  
D Chu ◽  
D Pizzuti ◽  
...  

This study evaluated the in vitro activity of A-86719.1, a novel 2-pyridone antimicrobial agent. The drug inhibited all tested members of the family Enterobacteriaceae at < or = 0.5 microgram/ml and all tested Pseudomonas aeruginosa, Burkholderia (Pseudomonas) cepacia, and Xanthomonas maltophilia strains at < or = 2 micrograms/ml. All but two strains of gram-positive bacteria were inhibited by < or = 1 microgram of the new drug per ml, including isolates highly resistant to ciprofloxacin.


1994 ◽  
Vol 40 (4) ◽  
pp. 292-297 ◽  
Author(s):  
David A. Hart ◽  
Donald E. Woods

Urokinase is a proteinase that normally functions as a plasminogen activator. It is detected in a number of tissues and can be expressed by inflammatory cells such as macrophages and polymorphonuclear leucocytes. Addition of human urokinase to cultures of mucoid or nonmucoid variants of Pseudomonas aeruginosa (strain PAO and clinical isolates from patients with cystic fibrosis) or Pseudomonas cepacia incubated in a minimal medium under nonshaking (oxygen limited) conditions led to dose-dependent enhancement of bacterial growth. The enzyme exhibited a minimal effect on the growth of bacteria when cultured under more intense aeration conditions. This enhancement of bacterial growth by urokinase required the presence of active enzyme and was not detected with inactivated enzyme or noncatalytic domains of the enzyme. Enhancement of bacterial growth was not observed following incubation of P. aeruginosa with other proteinases including thrombin, neutrophil elastase, trypsin, chymotrypsin, or pseudomonas elastase and pseudomonas alkaline proteinase. Therefore, the observed effect of urokinase was relatively specific for this enzyme. As urokinase is a natural constituent of the lung, this enzyme could contribute to bacterial growth during pulmonary infections, particularly in an inflammatory environment in which the oxygen tension may be reduced.Key words: plasminogen activators, Pseudomonas aeruginosa, bacterial growth, urokinase, host proteinases.


Author(s):  
Baydaa Hussein ◽  
Zainab A. Aldhaher ◽  
Shahrazad Najem Abdu-Allah ◽  
Adel Hamdan

Background: Biofilm is a bacterial way of life prevalent in the world of microbes; in addition to that it is a source of alarm in the field of health concern. Pseudomonas aeruginosa is a pathogenic bacterium responsible for all opportunistic infections such as chronic and severe. Aim of this study: This paper aims to provide an overview of the promotion of isolates to produce a biofilm in vitro under special circumstances, to expose certain antibiotics to produce phenotypic evaluation of biofilm bacteria. Methods and Materials: Three diverse ways were used to inhibited biofilm formation of P.aeruginosa by effect of phenolic compounds extracts from strawberries. Isolates produced biofilm on agar MacConkey under certain circumstances. Results: The results showed that all isolates were resistant to antibiotics except sensitive to azithromycin (AZM, 15μg), and in this study was conducted on three ways to detect the biofilm produced, has been detected by the biofilm like Tissue culture plate (TCP), Tube method (TM), Congo Red Agar (CRA). These methods gave a clear result of these isolates under study. Active compounds were analyzed in both extracts by Gas Chromatography-mass Spectrometry which indicate High molecular weight compound with a long hydrocarbon chain. Conclusion: Phenolic compounds could behave as bioactive material and can be useful to be used in pharmaceutical synthesis. Phenolic contents which found in leaves and fruits extracts of strawberries shows antibacterial activity against all strains tested by the ability to reduce the production of biofilm formation rate.


Author(s):  
Karlynne Freire Mendonça ◽  
José Klauber Roger Carneiro ◽  
Maria Auxiliadora Silva Oliveira

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.


2017 ◽  
Vol 2 (3) ◽  
pp. 150-163
Author(s):  
Ekajayanti Kining ◽  
Syamsul Falah ◽  
Novik Nurhidayat

Pseudomonas aeruginosa is one of opportunistic pathogen forming bacterial biofilm. The biofilm sustains the bacterial survival and infections. This study aimed to assess the activity of water extract of papaya leaves on inhibition of cells attachment, growth and degradation of the biofilm using crystal violet (CV) biofilm assay. Research results showed that water extract of papaya leaves contains alkaloids, tanins, flavonoids, and steroids/terpenoids and showed antibacterial activity and antibiofilm against P. aeruginosa. Addition of extract can inhibit the cell attachment and was able to degrade the biofilm of 40.92% and 48.058% respectively at optimum conditions: extract concentration of 25% (v/v), temperature 37.5 °C and contact time 45 minutes. With a concentration of 25% (v/v), temperature of 50 °C and the contact time of 3 days, extract of papaya leaves can inhibit the growth of biofilms of 39.837% v/v.


2019 ◽  
Vol 17 (3) ◽  
pp. 140-148 ◽  
Author(s):  
A. Ouelhadj ◽  
L. Ait Salem ◽  
D. Djenane

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.


Sign in / Sign up

Export Citation Format

Share Document