scholarly journals Caspofungin and Polymyxin B Reduce the Cell Viability and Total Biomass of Mixed Biofilms of Carbapenem-Resistant Pseudomonas aeruginosa and Candida spp.

2020 ◽  
Vol 11 ◽  
Author(s):  
Luciana Fernandes ◽  
Bruna Nakanishi Fortes ◽  
Nilton Lincopan ◽  
Kelly Ishida
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Inhibitory Activity ◽  
Inhibitory Concentration ◽  
Polymyxin B ◽  
Antibiofilm Activity ◽  
Total Biomass ◽  
Planktonic Cells ◽  
Carbapenem Resistant ◽  
Cell Counts ◽  
Viable Cells

Pseudomonas aeruginosa and Candida spp. are biofilm-forming pathogens commonly found colonizing medical devices, being mainly associated with pneumonia and bloodstream infections. The coinfection by these pathogens presents higher mortality rates when compared to those caused by a single microbial species. This study aimed to evaluate the antibiofilm activity of echinocandins and polymyxin B (PMB) against polymicrobial biofilms of carbapenem-resistant (CR) Pseudomonas aeruginosa and Candida spp. (C. albicans, C. parapsilosis, C. tropicalis, and C. glabrata). In addition, we tested the antimicrobial effect on their planktonic and monomicrobial biofilm counterparties. Interestingly, beyond inhibition of planktonic [minimum inhibitory concentration (MIC) = 0.5 μg/ml] and biofilm [minimum biofilm inhibitory concentration (MBIC)50 ≤ 2–8 μg/ml] growth of P. aeruginosa, PMB was also effective against planktonic cells of C. tropicalis (MIC = 2 μg/ml), and polymicrobial biofilms of CR P. aeruginosa with C. tropicalis (MBIC50 ≤ 2 μg/ml), C. parapsilosis (MBIC50 = 4–16 μg/ml), C. glabrata (MBIC50 = 8–16 μg/ml), or C. albicans (MBIC50 = 8–64 μg/ml). On the other hand, while micafungin (MFG) showed highest inhibitory activity against planktonic (MIC ≤ 0.008–0.5 μg/ml) and biofilm (MBIC50 ≤ 2–16 μg/ml) growth of Candida spp.; caspofungin (CAS) displays inhibitory activity against planktonic cells (MIC = 0.03–0.25 μg/ml) and monomicrobial biofilms (MBIC50 ≤ 2–64 μg/ml) of Candida spp., and notably on planktonic and monomicrobial biofilms of CR P. aeruginosa (MIC or MBIC50 ≥ 64 μg/ml). Particularly, for mixed biofilms, while CAS reduced significantly viable cell counts of CR P. aeruginosa and Candida spp. at ≥32 and ≥ 2 μg/ml, respectively; PMB was effective in reducing viable cells of CR P. aeruginosa at ≥2 μg/ml and Candida spp. at ≥8 μg/ml. Similar reduction of viable cells was observed for CAS (32–64 μg/ml) combined with PMB (2 μg/ml). These findings highlight the potential of PMB and CAS for the treatment of polymicrobial infections caused by Candida spp. and critical priority CR P. aeruginosa.

Reservoirs of resistance: polymyxin resistance in veterinary-associated companion animal isolates of Pseudomonas aeruginosa

2019 ◽  
Vol 185 (7) ◽  
pp. 206-206 ◽  
Author(s):  
Andrea Scott ◽  
Sian Pottenger ◽  
Dorina Timofte ◽  
Matthew Moore ◽  
Laura Wright ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Pathogenic Bacteria ◽  
Inhibitory Concentration ◽  
Respiratory Infections ◽  
Companion Animals ◽  
Opportunistic Pathogen ◽  
Polymyxin B ◽  
Potential Reservoir ◽  
Human Infections ◽  
Animal Isolates

BackgroundPseudomonas aeruginosa is an opportunistic pathogen and a major cause of infections. Widespread resistance in human infections are increasing the use of last resort antimicrobials such as polymyxins. However, these have been used for decades in veterinary medicine. Companion animals are an understudied source of antimicrobial resistant P. aeruginosa isolates. This study evaluated the susceptibility of P. aeruginosa veterinary isolates to polymyxins to determine whether the veterinary niche represents a potential reservoir of resistance genes for pathogenic bacteria in both animals and humans.Methods and resultsClinical P. aeruginosa isolates (n=24) from UK companion animals were compared for antimicrobial susceptibility to a panel of human-associated isolates (n=37). Minimum inhibitory concentration (MIC) values for polymyxin B and colistin in the companion animals was significantly higher than in human isolates (P=0.033 and P=0.013, respectively). Genotyping revealed that the veterinary isolates were spread throughout the P. aeruginosa population, with shared array types from human infections such as keratitis and respiratory infections, suggesting the potential for zoonotic transmission. Whole genome sequencing revealed mutations in genes associated with polymyxin resistance and other antimicrobial resistance-related genes.ConclusionThe high levels of resistance to polymyxin shown here, along with genetic similarities between some human and animal isolates, together suggest a need for sustained surveillance of this veterinary niche as a potential reservoir for resistant, clinically relevant bacteria in both animals and humans.

scholarly journals The Urinary Antibiotic 5-Nitro-8-Hydroxyquinoline (Nitroxoline) Reduces the Formation and Induces the Dispersal of Pseudomonas aeruginosa Biofilms by Chelation of Iron and Zinc

2012 ◽  
Vol 56 (11) ◽  
pp. 6021-6025 ◽  
Author(s):  
A. Sobke ◽  
M. Klinger ◽  
B. Hermann ◽  
S. Sachse ◽  
S. Nietzsche ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Broad Spectrum ◽  
Viable Cell ◽  
Antibiofilm Activity ◽  
Content Type ◽  
Cell Counts ◽  
Iron And Zinc ◽  
Chelation Of Iron

ABSTRACTSince cations have been reported as essential regulators of biofilm, we investigated the potential of the broad-spectrum antimicrobial and cation-chelator nitroxoline as an antibiofilm agent. Biofilm mass synthesis was reduced by up to 80% at sub-MIC nitroxoline concentrations inPseudomonas aeruginosa, and structures formed were reticulate rather than compact. In preformed biofilms, viable cell counts were reduced by 4 logs at therapeutic concentrations. Complexation of iron and zinc was demonstrated to underlie nitroxoline's potent antibiofilm activity.

scholarly journals Evaluation of the interaction between polymyxin B and Pseudomonas aeruginosa biofilm and planktonic cells: reactive oxygen species induction and zeta potential

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Marlucy Rodrigues Lima ◽  
Gabriella Freitas Ferreira ◽  
Wallace Ribeiro Nunes Neto ◽  
Joveliane de Melo Monteiro ◽  
Áquila Rodrigues Costa Santos ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Pseudomonas Aeruginosa ◽  
Zeta Potential ◽  
Reactive Oxygen ◽  
Polymyxin B ◽  
Oxygen Species ◽  
Planktonic Cells

Assembly and antifungal effect of a new fluconazole-carrier nanosystem

2020 ◽  
Vol 15 (4) ◽  
pp. 273-285 ◽  
Author(s):  
Taynara MT de Lima ◽  
Laís S Arias ◽  
Letícia F Afanaci ◽  
Raphael FB Ferraresse ◽  
Francisco N de S Neto ◽  
...  
Keyword(s):  
Minimum Inhibitory Concentration ◽  
Candida Glabrata ◽  
Inhibitory Concentration ◽  
Fungal Infections ◽  
Oxide Nanoparticles ◽  
Total Biomass ◽  
Planktonic Cells ◽  
Antifungal Effect ◽  
Concentration Determination ◽  
Antifungal Effects

Aim: To assemble, characterize and assess the antifungal effects of a new fluconazole (FLZ)-carrier nanosystem. Materials & methods: The nanosystem was prepared by loading FLZ on chitosan (CS)-coated iron oxide nanoparticles (IONPs). Antifungal effects were evaluated on planktonic cells (by minimum inhibitory concentration determination) and on biofilms (by quantification of cultivable cells, total biomass, metabolism and extracellular matrix) of Candida albicans and Candida glabrata. Results: Characterization results ratified the formation of a nanosystem (<320 nm) with FLZ successfully embedded. IONPs-CS-FLZ nanosystem reduced minimum inhibitory concentration values and, in general, showed similar antibiofilm effects compared with FLZ alone. Conclusion: IONPs-CS-FLZ nanosystem was more effective than FLZ mainly in inhibiting Candida planktonic cells. This nanocarrier has potential to fight fungal infections.

scholarly journals Ceftazidime–avibactam and ceftolozane–tazobactam susceptibility of multidrug resistant Pseudomonas aeruginosa strains in Hungary

2020 ◽  
pp. 1-5 ◽  
Author(s):  
Dustin O'Neall ◽  
Emese Juhász ◽  
Ákos Tóth ◽  
Edit Urbán ◽  
Judit Szabó ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Inhibitory Concentration ◽  
Carbapenem Resistance ◽  
Multidrug Resistant ◽  
Test Results ◽  
Diffusion Test ◽  
Microdilution Method ◽  
Carbapenem Resistant ◽  
Gradient Diffusion ◽  
Broth Microdilution Method

Abstract Our objective was to compare the activity ceftazidime-avibactam (C/A) and ceftolozane–tazobactam (C/T) against multidrug (including carbapenem) resistant Pseudomonas aeruginosa clinical isolates collected from six diagnostic centers in Hungary and to reveal the genetic background of their carbapenem resistance. Two hundred and fifty consecutive, non-duplicate, carbapenem-resistant multidrug resistant (MDR) P. aeruginosa isolates were collected in 2017. Minimal inhibitory concentration values of ceftazidime, cefepime, piperacillin/tazobactam, C/A and C/T were determined by broth microdilution method and gradient diffusion test. Carbapenem inactivation method (CIM) test was performed on all isolates. Carbapenemase-encoding blaVIM, blaIMP, blaKPC, blaOXA-48-like and blaNDM genes were identified by multiplex PCR. Of the isolates tested, 33.6& and 32.4& showed resistance to C/A and C/T, respectively. According to the CIM test results, 26& of the isolates were classified as carbapenemase producers. The susceptibility of P. aeruginosa isolates to C/A and C/T without carbapenemase production was 89& and 91&, respectively. Of the CIM-positive isolates, 80& were positive for blaVIM and 11& for blaNDM. The prevalence of Verona integron-encoded metallo-beta-lactamase (VIM)-type carbapenemase was 20.8&. NDM was present in 2.8& of the isolates. Although the rate of carbapenemase-producing P. aeruginosa strains is high, a negative CIM result indicates that either C/A or C/T could be effective even if carbapenem resistance has been observed.

scholarly journals Prevalence and clinical outcomes of episodes of ventilator-associated pneumonia caused by SPM-1-producing and non-producing imipenem-resistant Pseudomonas aeruginosa

2011 ◽  
Vol 44 (5) ◽  
pp. 604-606 ◽  
Author(s):  
Guilherme Henrique Campos Furtado ◽  
Ana Cristina Gales ◽  
Luciana Baria Perdiz ◽  
Anderson Fernandes Santos ◽  
Eduardo Alexandrino Servolo de Medeiros
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Clinical Outcomes ◽  
Respiratory Infections ◽  
Carbapenem Resistance ◽  
Polymyxin B ◽  
Ventilator Associated Pneumonia ◽  
Antimicrobial Drugs ◽  
Major Mechanism ◽  
Carbapenem Resistant ◽  
Related Mortality

INTRODUCTION: Pseudomonas aeruginosa is a leading cause of ventilator-associated pneumonia (VAP) and exhibits high rates of resistance to several antimicrobial drugs. The carbapenens are usually the drugs of choice against this microorganism. However, the carbapenem resistance has increased among these strains worldwide. The presence of metallo-β-lactamases (MBL) has been pointed out as a major mechanism of resistance among these strains. No previous study addressed outcomes of respiratory infections caused by these strains. METHODS: Our group sought to analyze the epidemiology and clinical outcomes of patients with VAP caused by imipenem-resistant P. aeruginosa. A total of 29 clinical isolates of carbapenem-resistant Pseudomonas aeruginosa were screened for metallo-β-lactamase (MBL) genes. RESULTS: Demographic and clinical variables were similar between the SPM-1-producing and non-SPM-1-producing group. Five (17.2%) isolates were positive for blaSPM-1. No other MBL gene was found. All patients were treated with polymyxin B. The infection-related mortality was 40% and 54.2% for SPM-1-producing and -non-producing isolates, respectively. CONCLUSIONS: There were no differences in epidemiological and clinical outcomes between the two groups.

scholarly journals Synergistic and antibiofilm activity of the antimicrobial peptide P5 against carbapenem-resistant Pseudomonas aeruginosa

2019 ◽  
Vol 1861 (7) ◽  
pp. 1329-1337 ◽  
Author(s):  
Melina Martinez ◽  
Sónia Gonçalves ◽  
Mário R. Felício ◽  
Patricia Maturana ◽  
Nuno C. Santos ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antimicrobial Peptide ◽  
Antibiofilm Activity ◽  
Carbapenem Resistant

Anti-Pseudomonas aeruginosa Activity of Metal Schiff Base Complex and Probiotics Against Planktonic- and Biofilm-Growing Cells

2020 ◽  
Vol 18 ◽  
Author(s):  
Sepideh Hassanzadeh ◽  
Sudabeh Ebrahimi ◽  
Sara Ganjloo ◽  
Saeid Amel Jamehdar ◽  
Samaneh Dolatabadi
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Schiff Base ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Schiff Base Complex ◽  
Diffusion Method ◽  
Antibiofilm Activity ◽  
Planktonic Cells ◽  
Biochemical Tests ◽  
Base Complex

Introduction: The biofilm formation by Pseudomonas aeruginosa seems to protect the bacteria from antibiotics since these entities are highly resistant to such antimicrobial agents. The aim of this study was to investigate the role of Lactobacillus salivarus, Lactobacillus plantarum supernatants and CuII Schiff base complex in eliminating planktonic cells and biofilm of P. aeruginosa. Methods: : One hundred specimens of blood, urine, cerebrospinal fluid, respiratory samples, and wound swabs were collected from patients attending three hospitals in Mashhad. All specimens were identified by biochemical tests. The susceptibility of the isolates to the conventional antibiotics were assessed using disk diffusion method. The biofilm formation ability of P. aeruginosa isolates was evaluated by crystal violet assay and confirmed using PCR. The anti-planktonic and anti-biofilm ability of L. salivarus, L. plantarum supernatants and CuII Schiff base complex was evaluated separately in P. aeruginosa isolates. Results and Conclusion: The highest and lowest resistance rates was detected in Cefazoline (95%) and cefepime (23%), respectively. The thickest biofilm was produced by 8% of P. aeruginosa isolates, 9% and 83% of the isolates were considered as moderate and weak biofilm producers, respectively. The rhlR and lasR genes was reported in 100% of the isolates, but algD gene was existence in 92% of them. Particularly, the CuII Schiff base complex could affect both planktonic and biofilm cells by the lowest concentration in comparison of probiotic supernatants. L. plantarum supernatant inhibited planktonic cells at a lower concentration than L. salivarius. Also, L. salivarius showed better antibiofilm activity than another probiotic in lower doses of supernatant. Unlike that these compounds have not completely eliminated biofilm cells, but only reduced the biofilm formation.Metal Schiff base complex and Lactobacillus supernatants is a potent antimicrobial agent against Pseudomonas aeruginosa biofilm cells.

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