scholarly journals Bidirectional alterations in antibiotics susceptibility in Staphylococcus aureus - Pseudomonas aeruginosa dual-species biofilm

2018 ◽  
Author(s):  
Elena Y. Trizna ◽  
Maria N. Yarullina ◽  
Diana R. Baidamshina ◽  
Farida S. Akhatova ◽  
Elvira V. Rozhina ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Treatment Efficacy ◽  
Antimicrobial Agents ◽  
Fold Increase ◽  
Antimicrobial Treatment ◽  
Mixed Infections ◽  
Similar Increase ◽  
Efficient Treatment ◽  
Antibiotics Susceptibility ◽  
Efficacy Of Treatment

ABSTRACTWhile in biofilms bacteria are embedded into an extracellular matrix which forms inaccessible barrier for antimicrobials thereby drastically increasing the concentrations of antibiotics required for treatment. Here we show that the susceptibility of S. aureus and P. aeruginosa to antibiotics in mixed biofilms significantly differs from monoculture biofilms depending on both conditions and chosen antimicrobial agents. While S. aureus could completely avoid vancomycin, ampicillin and ceftriaxone by embedding into the biofilm of P. aeruginosa, the very same consortium was characterized by 10–fold increase in susceptibility to broad-spectrum antimicrobials like ciprofloxacin and aminoglycosides compared to monocultures. These data clearly indicate that efficient treatment of biofilm-associated mixed infections requires antimicrobials active against both pathogens, since the interbacterial antagonism would enhance the efficacy of treatment. Moreover, similar increase in antibiotics efficacy was observed when P. aeruginosa suspension was added to the mature S. aureus biofilm, compared to S. aureus monoculture, and vice versa. These findings open promising perspectives to increase the antimicrobial treatment efficacy of the wounds infected with nosocomial pathogens by the transplantation of the skin residential microflora.

Bidirectional alterations in antibiotics susceptibility in Staphylococcus aureus - Pseudomonas aeruginosa dual-species biofilm

2020 ◽  
Author(s):  
Elena Trizna ◽  
Diana Baidamshina ◽  
Maria Yarullina ◽  
Anna Mironova ◽  
Alsu Khabibrakhmanova ◽  
...  
Keyword(s):  
Treatment Efficacy ◽  
Antimicrobial Agents ◽  
Fold Increase ◽  
Antimicrobial Treatment ◽  
Mixed Infections ◽  
Similar Increase ◽  
Russian Science ◽  
Efficient Treatment ◽  
Antibiotics Susceptibility ◽  
Efficacy Of Treatment

<p>While in biofilms bacteria are embedded into an extracellular matrix which forms inaccessible barrier for antimicrobials thereby drastically increasing the concentrations of antibiotics required for treatment. Here we show that the susceptibility of <em>S. aureus</em> and <em>P. aeruginosa</em> to antibiotics in mixed biofilms significantly differs from monoculture biofilms depending on both conditions and chosen antimicrobial agents. While <em>S. aureus</em> could completely avoid vancomycin, ampicillin and ceftriaxone by embedding into the biofilm of <em>P. aeruginosa</em>, the very same consortium was characterized by 10–fold increase in susceptibility to broad-spectrum antimicrobials like ciprofloxacin and aminoglycosides compared to monocultures. These data clearly indicate that efficient treatment of biofilm-associated mixed infections requires antimicrobials active against both pathogens, since the interbacterial antagonism would enhance the efficacy of treatment. Moreover, similar increase in antibiotics efficacy was observed when <em>P. aeruginosa</em> suspension was added to the mature<em> S. aureus</em> biofilm, compared to <em>S. aureus</em> monoculture, and vice versa. These findings open promising perspectives to increase the antimicrobial treatment efficacy of the wounds infected with nosocomial pathogens by the transplantation of the skin residential microflora.</p> <p>This work was supported by the Russian Science Foundation (Project №20-64-47014)</p>

scholarly journals Bidirectional alterations in antibiotics susceptibility in Staphylococcus aureus—Pseudomonas aeruginosa dual-species biofilm

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Elena Y. Trizna ◽  
Maria N. Yarullina ◽  
Diana R. Baidamshina ◽  
Anna V. Mironova ◽  
Farida S. Akhatova ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Treatment Efficacy ◽  
Antimicrobial Treatment ◽  
Mixed Infections ◽  
Similar Increase ◽  
Beta Lactams ◽  
Nosocomial Pathogens ◽  
Tenfold Increase ◽  
Antibiotics Susceptibility

Abstract In mixed infections, the bacterial susceptibility differs significantly compared to monocultures of bacteria, and generally the concentrations of antibiotics required for the treatment increases drastically. For S. aureus and P. aeruginosa dual species biofilms, it has been numerously reported that P. aeruginosa decreases S. aureus susceptibility to a broad range of antibiotics, including beta-lactams, glycopeptides, aminoglycosides, macrolides, while sensitizes to quinolones via secretion of various metabolites. Here we show that S. aureus also modulates the susceptibility of P. aeruginosa to antibiotics in mixed cultures. Thus, S. aureus—P. aeruginosa consortium was characterized by tenfold increase in susceptibility to ciprofloxacin and aminoglycosides compared to monocultures. The same effect could be also achieved by the addition of cell-free culture of S. aureus to P. aeruginosa biofilm. Moreover, similar increase in antibiotics efficacy could be observed following addition of S. aureus suspension to the P. aeruginosa mature biofilm, compared to P. aeruginosa monoculture, and vice versa. These findings open promising perspectives to increase the antimicrobial treatment efficacy of the wounds infected with nosocomial pathogens by the transplantation of the skin residential microflora.

scholarly journals In Vitro Activity of Tedizolid Compared to Linezolid and Five Other Antimicrobial Agents against 332 Anaerobic Isolates, Including Bacteroides fragilis Group, Prevotella, Porphyromonas, and Veillonella Species

2020 ◽  
Vol 64 (9) ◽  
Author(s):  
Ellie J. C. Goldstein ◽  
C. Vreni Merriam ◽  
Diane M. Citron
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Agents ◽  
Bacteroides Fragilis ◽  
Vitro Activity ◽  
Mixed Infections ◽  
In Vitro Activity ◽  
Content Type ◽  
Bacteroides Fragilis Group ◽  
Group Species

ABSTRACT Tedizolid’s anaerobic activity is unappreciated. In this study, it was active against all 332 anaerobic isolates tested at ≤2 μg/ml except Bilophila wadsworthia and was more active than linezolid against Bacteroides fragilis group species (MIC90, 1 μg/ml versus 2 to 4 μg/ml). Tedizolid was active against Gram-positive anaerobes (MIC90 for clostridia, 0.25 to 1 μg/ml; MIC90 for anaerobic cocci, ≤0.06 to 0.25 μg/ml). Our data coupled with clinical reports indicate that clinicians should consider its use in mixed infections where Staphylococcus aureus and anaerobes are involved.

scholarly journals Susceptibilities of Mycoplasma hominis, M. pneumoniae, and Ureaplasma urealyticum to GAR-936, Dalfopristin, Dirithromycin, Evernimicin, Gatifloxacin, Linezolid, Moxifloxacin, Quinupristin-Dalfopristin, and Telithromycin Compared to Their Susceptibilities to Reference Macrolides, Tetracyclines, and Quinolones

2001 ◽  
Vol 45 (9) ◽  
pp. 2604-2608 ◽  
Author(s):  
George E. Kenny ◽  
Frank D. Cartwright
Keyword(s):  
Mycoplasma Pneumoniae ◽  
Antimicrobial Agents ◽  
Ureaplasma Urealyticum ◽  
Mycoplasma Hominis ◽  
Fold Increase ◽  
Similar Increase ◽  
Fourfold Increase ◽  
Agar Dilution

ABSTRACT The susceptibilities of Mycoplasma hominis,Mycoplasma pneumoniae, and Ureaplasma urealyticum to eight new antimicrobial agents were determined by agar dilution.M. pneumoniae was susceptible to the new glycylcycline GAR-936 at 0.12 μg/ml and evernimicin at 4 μg/ml, but it was resistant to linezolid. It was most susceptible to dirithromycin, quinupristin-dalfopristin, telithromycin, reference macrolides, and josamycin. M. hominis was susceptible to linezolid, evernimicin, and GAR-936. It was resistant to macrolides and the ketolide telithromycin but susceptible to quinupristin-dalfopristin and josamycin. U. urealyticum was susceptible to evernimicin (8 to 16 μg/ml) and resistant to linezolid. It was less susceptible to GAR-936 (4.0 μg/ml) than to tetracycline (0.5 μg/ml). Telithromycin and quinupristin-dalfopristin were the most active agents against ureaplasmas (0.06 μg/ml). The new quinolone gatifloxacin was active against M. pneumoniae and M. hominis at 0.12 to 0.25 μg/ml and active against ureaplasmas at 1.0 μg/ml. The MICs of macrolides were markedly affected by pH, with an 8- to 32-fold increase in the susceptibility of M. pneumoniae as the pH increased from 6.9 to 7.8. A similar increase in susceptibility with increasing pH was also observed with ureaplasmas. Tetracyclines showed a fourfold increase of activity as the pH decreased 1 U, whereas GAR-936 showed a fourfold decrease in activity with a decrease in pH.

Dalbavancin for the Treatment of Complicated Gram-Positive Skin and Soft Tissue Infections

2020 ◽  
Vol 19 (3) ◽  
pp. 236-241 ◽  
Author(s):  
Vasilios Petrakis ◽  
Periklis Panagopoulos ◽  
Nikolaos Papanas
Keyword(s):  
Staphylococcus Aureus ◽  
Soft Tissue ◽  
Antimicrobial Agents ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Antimicrobial Treatment ◽  
Soft Tissue Infections ◽  
Gram Positive ◽  
Positive Skin ◽  
Methicillin Resistant ◽  
Complicated Skin

New antimicrobial agents have been developed to treat infections caused by methicillin-resistant Staphylococcus aureus and other multidrug-resistant pathogens. Dalbavancin is a novel semisynthetic lipoglycopeptide antibiotic, particularly active against methicillin-resistant Staphylococcus aureus. Due to its unique pharmacological characteristics and longer half-life, it can be administered once-weekly or every 15 days and in outpatient setting. Currently, it is indicated for complicated skin and soft tissue infections, but accumulating evidence points to its off-label efficacy in osteomyelitis and endocarditis. Further experience is still needed to increase our knowledge on the role of dalbavancin in a wider range of Gram-positive infections requiring prolonged antimicrobial treatment.

Post-antibiotic and post-antibiotic sub-MIC effects of gentamicin, sophoraflavanone G, and their combination against a clinical isolate of Staphylococcus aureus

2010 ◽  
Vol 4 (5) ◽  
pp. 821-826 ◽  
Author(s):  
Ruhollah Mirjani ◽  
Fatemeh Rafii ◽  
Mohammad Sharifzadeh ◽  
Massoud Amanlou ◽  
Ahmad R. Shahverdi
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Agents ◽  
Fold Increase ◽  
Dependent Manner ◽  
Combination Methods ◽  
Antibiotic Effect ◽  
Short Term Exposure ◽  
Drug Determination ◽  
Dosing Intervals

Abstract Background: Post-antibiotic effect (PAE) defines the potential of a drug to delay re-growth of a bacterial population after short-term exposure and removal of a drug. Determination of the PAE is recommended in preclinical evaluation of all new antimicrobial agents, because it influences optimal antimicrobial dosing intervals. Objective: Evaluate the PAE and PA-SME of gentamicin and sophoraflavanone G against Staphylococcus aureus (S. aureus) itself and in combination. Methods: A spectrophotometric method was used to determine the PAE and PA-SME. Results: Sophoraflavanone G and gentamicin, showed considerable PAE and PA-SME at the tested concentrations against S. aureus. The increased duration of PAE caused by sophoraflavanone G and gentamicin was dosedependent. In addition, sophoraflavanone G at sub-MIC concentrations enhanced the PAE and PA-SME of gentamicin in a dose-dependent manner. The highest enhancing effect was observed for gentamicin at the synergistic MIC and 1/2 the synergistic MIC levels against S. aureus 0.03 μg/mL (30 ng/mL) of sophoraflavanone G (with PAE=55 minutes). It enhanced the post-antibiotic sub-MIC effect (PA-SME) duration of gentamicin at concentrations of 4 μg/mL from 15 minutes to 80 minutes (a six-fold increase). Conclusion: Sophoraflavanone G is promising for the preparation of an effective therapeutic formulation against gentamicin-resistant S. aureus.

Biological Evaluation of Selected 1,2,3-triazole Derivatives as Antibacterial and Antibiofilm Agents

2020 ◽  
Vol 20 (24) ◽  
pp. 2186-2191
Author(s):  
Lialyz Soares Pereira André ◽  
Renata Freire Alves Pereira ◽  
Felipe Ramos Pinheiro ◽  
Aislan Cristina Rheder Fagundes Pascoal ◽  
Vitor Francisco Ferreira ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Public Health Problem ◽  
Biological Evaluation ◽  
Major Public Health Problem ◽  
Community Environments ◽  
Scanning Electron

Background: Resistance to antimicrobial agents is a major public health problem, being Staphylococcus aureus prevalent in infections in hospital and community environments and, admittedly, related to biofilm formation in biotic and abiotic surfaces. Biofilms form a complex and structured community of microorganisms surrounded by an extracellular matrix adhering to each other and to a surface that gives them even more protection from and resistance against the action of antimicrobial agents, as well as against host defenses. Methods: Aiming to control and solve these problems, our study sought to evaluate the action of 1,2,3- triazoles against a Staphylococcus aureus isolate in planktonic and in the biofilm form, evaluating the activity of this triazole through Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) tests. We have also performed cytotoxic evaluation and Scanning Electron Microscopy (SEM) of the biofilms under the treatment of the compound. The 1,2,3-triazole DAN 49 showed bacteriostatic and bactericidal activity (MIC and MBC 128 μg/mL). In addition, its presence interfered with the biofilm formation stage (1/2 MIC, p <0.000001) and demonstrated an effect on young preformed biofilm (2 MICs, p <0.05). Results: Scanning Electron Microscopy images showed a reduction in the cell population and the appearance of deformations on the surface of some bacteria in the biofilm under treatment with the compound. Conclusion: Therefore, it was possible to conclude the promising anti-biofilm potential of 1,2,3-triazole, demonstrating the importance of the synthesis of new compounds with biological activity.

scholarly journals Pseudomonas aeruginosa PA14 Enhances the Efficacy of Norfloxacin against Staphylococcus aureus Newman Biofilms

2020 ◽  
Vol 202 (18) ◽  
Author(s):  
Giulia Orazi ◽  
Fabrice Jean-Pierre ◽  
George A. O’Toole
Keyword(s):  
Cystic Fibrosis ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Agents ◽  
Respiratory Infections ◽  
Multiple Infection ◽  
Bacterial Biofilms ◽  
Interspecies Interactions ◽  
Chronic Infections ◽  
Content Type

ABSTRACT The thick mucus within the airways of individuals with cystic fibrosis (CF) promotes frequent respiratory infections that are often polymicrobial. Pseudomonas aeruginosa and Staphylococcus aureus are two of the most prevalent pathogens that cause CF pulmonary infections, and both are among the most common etiologic agents of chronic wound infections. Furthermore, the ability of P. aeruginosa and S. aureus to form biofilms promotes the establishment of chronic infections that are often difficult to eradicate using antimicrobial agents. In this study, we found that multiple LasR-regulated exoproducts of P. aeruginosa, including 2-heptyl-4-hydroxyquinoline N-oxide (HQNO), siderophores, phenazines, and rhamnolipids, likely contribute to the ability of P. aeruginosa PA14 to shift S. aureus Newman norfloxacin susceptibility profiles. Here, we observe that exposure to P. aeruginosa exoproducts leads to an increase in intracellular norfloxacin accumulation by S. aureus. We previously showed that P. aeruginosa supernatant dissipates the S. aureus membrane potential, and furthermore, depletion of the S. aureus proton motive force recapitulates the effect of the P. aeruginosa PA14 supernatant on shifting norfloxacin sensitivity profiles of biofilm-grown S. aureus Newman. From these results, we hypothesize that exposure to P. aeruginosa PA14 exoproducts leads to increased uptake of the drug and/or an impaired ability of S. aureus Newman to efflux norfloxacin. Surprisingly, the effect observed here of P. aeruginosa PA14 exoproducts on S. aureus Newman susceptibility to norfloxacin seemed to be specific to these strains and this antibiotic. Our results illustrate that microbially derived products can alter the ability of antimicrobial agents to kill bacterial biofilms. IMPORTANCE Pseudomonas aeruginosa and Staphylococcus aureus are frequently coisolated from multiple infection sites, including the lungs of individuals with cystic fibrosis (CF) and nonhealing diabetic foot ulcers. Coinfection with P. aeruginosa and S. aureus has been shown to produce worse outcomes compared to infection with either organism alone. Furthermore, the ability of these pathogens to form biofilms enables them to cause persistent infection and withstand antimicrobial therapy. In this study, we found that P. aeruginosa-secreted products dramatically increase the ability of the antibiotic norfloxacin to kill S. aureus biofilms. Understanding how interspecies interactions alter the antibiotic susceptibility of bacterial biofilms may inform treatment decisions and inspire the development of new therapeutic strategies.

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