scholarly journals In vivo activity of human-simulated regimens of imipenem alone and in combination with relebactam against Pseudomonas aeruginosa in the murine thigh infection model

2020 ◽  
Author(s):  
Sergio Reyes ◽  
Kamilia Abdelraouf ◽  
David P Nicolau
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Clinical Utility ◽  
Infection Model ◽  
Treatment Groups ◽  
Log Reduction ◽  
Wide Range ◽  
To Receive ◽  
Inhibitor Combination

Abstract Background Imipenem/relebactam is a carbapenem/β-lactamase inhibitor combination with in vitro activity against Pseudomonas aeruginosa and Enterobacterales, including KPC producers. Objectives To provide translational data to support the clinical utility of the imipenem/relebactam 500/250 mg q6h regimen using a human-simulated regimen (HSR) of imipenem/relebactam, compared with imipenem alone, against a phenotypically and genotypically diverse population of P. aeruginosa. Methods Twenty-nine P. aeruginosa isolates, including KPC (n = 6), PDC (n = 9), PAO (n = 4), GES (n = 5) and VIM (n = 1) producers, were used for the in vivo efficacy studies. Neutropenic mice were thigh-inoculated and randomized to receive HSRs of either imipenem 500 mg q6h, imipenem 1 g q8h, imipenem/relebactam 500/250 mg q6h or saline. Results Twenty-seven of the 29 isolates examined were imipenem resistant, with 24/29 isolates showing imipenem MICs of ≥32 mg/L. The addition of relebactam decreased the MICs up to 64-fold; imipenem/relebactam MICs ranged from 0.25 to >32 mg/L. Efficacies of the imipenem monotherapies and the imipenem/relebactam therapy were comparable for the two imipenem-susceptible organisms. Among the imipenem-resistant isolates, an increased mean growth was observed in the imipenem 500 mg q6h HSR and 1 g q8h HSR treatment groups of 1.31 ± 1.01 and 0.18 ± 1.67 log10 cfu/thigh, respectively. In contrast, a ≥2 log reduction in bacterial density was observed in 27/29 (93%) of the imipenem-resistant isolates subjected to imipenem/relebactam 500/250 mg q6h HSR. Conclusions The imipenem/relebactam 500/250 mg q6h HSR demonstrated superior in vivo activity compared with the conventionally employed imipenem regimens against MDR P. aeruginosa over a wide range of imipenem/relebactam MICs.

scholarly journals Tea polyphenols as an antivirulence compound Disrupt Quorum-Sensing Regulated Pathogenicity of Pseudomonas aeruginosa

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Hongping Yin ◽  
Yifeng Deng ◽  
Huafu Wang ◽  
Wugao Liu ◽  
Xiyi Zhuang ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Water Extract ◽  
Tea Polyphenols ◽  
Infection Model ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Treatment Groups

Abstract Green tea, a water extract of non-fermented leaves of Camellia sinensis L., is one of the nonalcoholic beverages in China. It is becoming increasingly popular worldwide, because of its refreshing, mild stimulant and medicinal properties. Here we examined the quorum sensing inhibitory potentials of tea polyphenols (TP) as antivirulence compounds both in vitro and in vivo. Biosensor assay data suggested minimum inhibitory concentrations (MICs) of TP against selected pathogens were 6.25 ~ 12.5 mg/mL. At sub-MIC, TP can specifically inhibit the production of violacein in Chromobacterium violaceum 12472 with almost 98% reduction at 3.125 mg/mL without affecting its growth rate. Moreover, TP exhibited inhibitory effects on virulence phenotypes regulated by QS in Pseudomonas aeruginosa. The total proteolytic activity, elastase, swarming motility and biofilm formation were reduced in a concentration-dependent manner. In vivo, TP treatment resulted in the reduction of P. aeruginosa pathogenicity in Caenorhabditis elegans. When its concentration was 3.125 mg/mL, the survival rate reached 63.3%. In the excision wound infection model, the wound contraction percentage in treatment groups was relatively increased and the colony-forming units (CFU) in the wound area were significantly decreased. These results suggested that TP could be developed as a novel non-antibiotic QS inhibitor without killing the bacteria but as an antivirulence compound to control bacterial infection.

scholarly journals OligoG CF-5/20 Disruption of Mucoid Pseudomonas aeruginosa Biofilm in a Murine Lung Infection Model

2016 ◽  
Vol 60 (5) ◽  
pp. 2620-2626 ◽  
Author(s):  
Wang Hengzhuang ◽  
Zhijun Song ◽  
Oana Ciofu ◽  
Edvar Onsøyen ◽  
Philip D. Rye ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Bacterial Infections ◽  
Infection Model ◽  
Dependent Manner ◽  
Clinical Value ◽  
Biofilm Growth ◽  
Content Type ◽  
Log Reduction

ABSTRACTBiofilm growth is a universal survival strategy for bacteria, providing an effective and resilient approach for survival in an otherwise hostile environment. In the context of an infection, a biofilm provides resistance and tolerance to host immune defenses and antibiotics, allowing the biofilm population to survive and thrive under conditions that would destroy their planktonic counterparts. Therefore, the disruption of the biofilm is a key step in eradicating persistent bacterial infections, as seen in many types of chronic disease. In these studies, we used bothin vitrominimum biofilm eradication concentration (MBEC) assays and anin vivomodel of chronic biofilm infection to demonstrate the biofilm-disrupting effects of an alginate oligomer, OligoG CF-5/20. Biofilm infections were established in mice by tracheal instillation of a mucoid clinical isolate ofPseudomonas aeruginosaembedded in alginate polymer beads. The disruption of the biofilm by OligoG CF-5/20 was observed in a dose-dependent manner over 24 h, with up to a 2.5-log reduction in CFU in the infected mouse lungs. Furthermore,in vitroassays showed that 5% OligoG CF-5/20 significantly reduced the MBEC for colistin from 512 μg/ml to 4 μg/ml after 8 h. These findings support the potential for OligoG CF-5/20 as a biofilm disruption agent which may have clinical value in reducing the microbial burden in chronic biofilm infections.

scholarly journals In VivoEfficacy of Anuran Trypsin Inhibitory Peptides against Staphylococcal Skin Infection and the Impact of Peptide Cyclization

2015 ◽  
Vol 59 (4) ◽  
pp. 2113-2121 ◽  
Author(s):  
U. Malik ◽  
O. N. Silva ◽  
I. C. M. Fensterseifer ◽  
L. Y. Chan ◽  
R. J. Clark ◽  
...  
Keyword(s):  
Antimicrobial Agents ◽  
Cyclic Peptide ◽  
Sequence Similarity ◽  
Infection Model ◽  
Content Type ◽  
Wide Range ◽  
Inhibitory Activities ◽  
The Impact

ABSTRACTStaphylococcus aureusis a virulent pathogen that is responsible for a wide range of superficial and invasive infections. Its resistance to existing antimicrobial drugs is a global problem, and the development of novel antimicrobial agents is crucial. Antimicrobial peptides from natural resources offer potential as new treatments against staphylococcal infections. In the current study, we have examined the antimicrobial properties of peptides isolated from anuran skin secretions and cyclized synthetic analogues of these peptides. The structures of the peptides were elucidated by nuclear magnetic resonance (NMR) spectroscopy, revealing high structural and sequence similarity with each other and with sunflower trypsin inhibitor 1 (SFTI-1). SFTI-1 is an ultrastable cyclic peptide isolated from sunflower seeds that has subnanomolar trypsin inhibitory activity, and this scaffold offers pharmaceutically relevant characteristics. The five anuran peptides were nonhemolytic and noncytotoxic and had trypsin inhibitory activities similar to that of SFTI-1. They demonstrated weakin vitroinhibitory activities againstS. aureus, but several had strong antibacterial activities againstS. aureusin anin vivomurine wound infection model. pYR, an immunomodulatory peptide fromRana sevosa, was the most potent, with complete bacterial clearance at 3 mg · kg−1. Cyclization of the peptides improved their stability but was associated with a concomitant decrease in antimicrobial activity. In summary, these anuran peptides are promising as novel therapeutic agents for treating infections from a clinically resistant pathogen.

scholarly journals Bactericidal Activities of Meropenem and Ertapenem against Extended-Spectrum-β-Lactamase-Producing Escherichia coli and Klebsiella pneumoniae in a Neutropenic Mouse Thigh Model

2007 ◽  
Vol 51 (4) ◽  
pp. 1481-1486 ◽  
Author(s):  
C. Andrew DeRyke ◽  
Mary Anne Banevicius ◽  
Hong Wei Fan ◽  
David P. Nicolau
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Pneumoniae ◽  
Infection Model ◽  
Bacterial Reduction ◽  
Efficacy Analysis ◽  
Percent Time ◽  
Extended Spectrum ◽  
Wide Range

ABSTRACT The purpose of this study was to examine the in vivo efficacies of meropenem and ertapenem against extended-spectrum-β-lactamase (ESBL)-producing isolates with a wide range of MICs. Human-simulated dosing regimens in mice were designed to approximate the free drug percent time above the MIC (fT>MIC) observed for humans following meropenem at 1 g every 8 h and ertapenem at 1 g every 24 h. An in vivo neutropenic mouse thigh infection model was used to examine the bactericidal effects against 31 clinical ESBL Escherichia coli and Klebsiella pneumoniae isolates and 2 non-ESBL isolates included for comparison at a standard 105 inoculum. Three isolates were examined at a high 107 inoculum as well. Meropenem displayed greater in vitro potency, with a median MIC (range) (μg/ml) of 0.125 (0.03 to 32), than did ertapenem, with 0.5 (0.012 to 128). Seven of the 31 ESBL isolates were removed from the efficacy analysis due to their inability to establish infection in the mouse model. When MICs were ≤1.5 μg/ml for ertapenem (≤0.5 μg/ml for meropenem), similar reductions in CFU (≈ 2-log kill) were observed for both ertapenem (fT>MIC ≥ 23%) and meropenem (fT>MIC ≥ 75%). Ertapenem showed bacterial regrowth for seven of eight isolates, with MICs of ≥2 μg/ml (fT>MIC ≤ 20%), while meropenem displayed antibacterial potency that varied from a static effect to a 1-log bacterial reduction in these isolates (fT>MIC = 30 to 65%). At a 107 inoculum, both agents eradicated bacteria due to adequate exposures (fT>MIC = 20 to 45%). Due to low MICs, no difference in bacterial kill was noted for the majority of ESBL isolates tested. However, for isolates with raised ertapenem MICs of ≥2 μg/ml, meropenem displayed sustained efficacy due to its greater in vitro potency and higher resultant fT>MIC.

scholarly journals In vivo pharmacodynamics of new-generation β-lactamase inhibitor taniborbactam (formerly VNRX-5133) in combination with cefepime against serine-β-lactamase-producing Gram-negative bacteria

2020 ◽  
Vol 75 (12) ◽  
pp. 3601-3610 ◽  
Author(s):  
Kamilia Abdelraouf ◽  
Safa Almarzoky Abuhussain ◽  
David P Nicolau
Keyword(s):  
Dose Fractionation ◽  
Infection Model ◽  
Bacterial Burden ◽  
Log Reduction ◽  
Clinical Dose ◽  
Dosing Frequency ◽  
New Generation ◽  
Inhibitor Combination ◽  
Lactamase Inhibitor

Abstract Objectives Cefepime/taniborbactam is a cephalosporin/cyclic boronate β-lactamase inhibitor combination under development for the treatment of infections due to MDR Enterobacterales and Pseudomonas aeruginosa. Using a neutropenic murine thigh infection model, we aimed to determine the pharmacokinetic/pharmacodynamic index, relative to taniborbactam exposure, that correlated most closely with the efficacy of the cefepime/taniborbactam combination and the magnitude of index required for efficacy against serine-β-lactamase-producing strains. Methods Twenty-six clinical Enterobacterales (expressing ESBLs, plasmid-mediated AmpC and/or carbapenemases of classes A or D; cefepime/taniborbactam combination MICs 0.06–16 mg/L) and 11 clinical P. aeruginosa (AmpC overproducing or KPC expressing; cefepime/taniborbactam combination MICs 1–16 mg/L) were evaluated. A cefepime human-simulated regimen (HSR) equivalent to a clinical dose of 2 g q8h as a 2 h infusion was given in combination with taniborbactam for 24 h. For a subset of P. aeruginosa isolates, a sub-therapeutic cefepime exposure was utilized. Results Dose-fractionation studies revealed that dosing frequency had no impact on taniborbactam potentiation of cefepime activity. Relative to the initial bacterial burden, the median taniborbactam fAUC0–24/MIC associated with 1 log kill in combination with the cefepime HSR for Enterobacterales and P. aeruginosa isolates was 2.62 and 0.46, respectively. In combination with sub-therapeutic cefepime, the median taniborbactam fAUC0–24/MIC associated with 1 and 2 log kill against AmpC-overproducing P. aeruginosa was 2.00 and 3.30, respectively, relative to the bacterial burden in the cefepime-treated groups. The taniborbactam HSR (equivalent to 0.5 g q8h as a 2 h infusion) was adequate to attain ≥1 log reduction against all test isolates. Conclusions Our data show that the cefepime/taniborbactam combination (2 g/0.5 g q8h as a 2 h infusion) exerts potent in vivo activity against cefepime-resistant isolates, including serine-carbapenemase producers.

scholarly journals Preclinical In Vitro and In Vivo Characterization of the Fully Human Monoclonal IgM Antibody KBPA101 Specific for Pseudomonas aeruginosa Serotype IATS-O11

2010 ◽  
Vol 54 (6) ◽  
pp. 2338-2344 ◽  
Author(s):  
Michael P. Horn ◽  
Adrian W. Zuercher ◽  
Martin A. Imboden ◽  
Michael P. Rudolf ◽  
Hedvika Lazar ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Treatment Options ◽  
Human Monoclonal Antibody ◽  
Human Monocyte ◽  
Peripheral Blood Lymphocytes ◽  
Infection Model ◽  
High Avidity ◽  
Burn Wound

ABSTRACT Pseudomonas aeruginosa infection in ventilator-associated pneumonia is a serious and often life-threatening complication in intensive care unit patients, and new treatment options are needed. We used B-cell-enriched peripheral blood lymphocytes from a volunteer immunized with a P. aeruginosa O-polysaccharide-toxin A conjugate vaccine to generate human hybridoma cell lines producing monoclonal antibodies specific for individual P. aeruginosa lipopolysaccharide serotypes. The fully human monoclonal antibody secreted by one of these lines, KBPA101, is an IgM/κ antibody that binds P. aeruginosa of International Antigenic Typing System (IATS) serotype O11 with high avidity (5.81 × 107 M−1 ± 2.8 × 107 M−1) without cross-reacting with other serotypes. KBPA101 specifically opsonized the P. aeruginosa of IATS O11 serotype and mediated complement-dependent phagocytosis in vitro by the human monocyte-like cell line HL-60 at a very low concentration (half-maximal phagocytosis at 0.16 ng/ml). In vivo evaluation of KBPA101 demonstrated a dose-response relationship for protection against systemic infections in a murine burn wound sepsis model, where 70 to 100% of animals were protected against lethal challenges with P. aeruginosa at doses as low as 5 μg/animal. Furthermore, a high efficacy of KBPA101 in protection from local respiratory infections in an acute lung infection model in mice was demonstrated. Preclinical toxicology evaluation on human tissue, in rabbits, and in mice did not indicate any toxicity of KBPA101. Based on these preclinical findings, the first human clinical trials have been initiated.

scholarly journals 1244. Assessment of the In Vivo Activity of Human-Simulated Exposure of WCK 4282 (High Dose Cefepime [FEP]-Tazobactam [TZB]) against Enterobacterales (EB) and Pseudomonas aeruginosa (PA) in the Neutropenic Murine Thigh Infection Model

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S640-S641
Author(s):  
Christian M Gill ◽  
Kamilia Abdelraouf ◽  
David P Nicolau
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Carbapenem Resistance ◽  
Bacterial Suspension ◽  
Infection Model ◽  
High Dose ◽  
Comparative Efficacy ◽  
Research Support ◽  
Variable Activity

Abstract Background Carbapenems are often used for infections due to extended-spectrum-β-lactamase (ESBL) and cephalosporinase (CSase)-producers. As increased carbapenem utilization is associated with the development of carbapenem resistance, antimicrobial stewardship has targeted non-carbapenem options. WCK 4282 (FEP 2 g-TZB 2 g) offers pharmacodynamically optimized TZB exposure and demonstrated potent activity in vitro against ESBL-phenotype isolates. We describe the pharmacodynamics of a WCK 4282 human-simulated regimen (HSR) in the neutropenic murine thigh model. Methods 19 clinical strains harboring ESBLs or CSase (EB; n=8 and PA; n=4) or serine-carbapenemases (EB; KPC n=4 or OXA-48-like n=3) were tested in vivo. Per CLSI, 19, 18, and 17 isolates were cefepime, ceftolozane/tazobactam, and piperacillin/tazobactam (TZP) non-susceptible, respectively. Thighs of neutropenic, female, CD-1 mice (3 per group) were inoculated with ~107 CFU/mL of bacterial suspension 2 h prior to dosing. Mice received WCK 4282 HSR, FEP HSR, or saline (controls) for 24 h. WCK 4282 HSR and FEP HSR provided plasma exposures in mice that were similar in f%T > MIC and fAUC to FEP-TZB 2 g-2 g and FEP 2 g, respectively, as IV infusions over 1.5 h q8h in humans. Bacterial densities and their changes at 24 h relative to 0 h controls were determined to assess efficacy and reported as mean±SD log10 CFU/thigh. Results Bacterial burdens were 5.81±0.36 at 0 h and 9.29±0.88 at 24 h in untreated controls. WCK 4282 produced potent activity against ESBL/CSase producing EB and PA with WCK 4282 MIC ≤ 16 mg/L; mean change in log10 CFU from 0 h was -1.70±0.77, while growth was observed with FEP alone. WCK 4282 produced variable activity against OXA-48-like harboring EB. Against KPC-harboring EB, WCK 4282 produced stasis to growth. Mean Log10 CFU changes are reported in Table 1 and Figure 1. Table 1. Comparative efficacy of FEP HSR and WCK 4282 HSR by genotypic β-lactamase Figure 1. Mean Change in log10CFU/thigh for 24 h controls, FEP HSR, and WCK 4282 HSR across the tested MIC distribution. Conclusion WCK 4282, a novel TZB containing regimen, resulted in enhance in vitro potency against ESBL/CSase and OXA-48-like producers. Humanized exposures of WCK 4282 produced substantial kill in vivo against ESBL/CSase producers with MICs ≤ 16 mg/L including FEP resistant/TZP non-susceptible PA. These data support further evaluations of WCK 4282 as a carbapenem-sparing regimen for ESBL/cephalosporinase harboring strains. Disclosures David P. Nicolau, PharmD, Cepheid (Other Financial or Material Support, Consultant, speaker bureau member or has received research support.)Merck & Co., Inc. (Consultant, Grant/Research Support, Speaker’s Bureau)Wockhardt (Grant/Research Support)

scholarly journals The ThiL enzyme is a valid antibacterial target essential for both thiamine biosynthesis and salvage pathways in Pseudomonas aeruginosa

2020 ◽  
Vol 295 (29) ◽  
pp. 10081-10091
Author(s):  
Hyung Jun Kim ◽  
Hyunjung Lee ◽  
Yunmi Lee ◽  
Inhee Choi ◽  
Yoonae Ko ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Drug Target ◽  
Biochemical Properties ◽  
Thiamine Pyrophosphate ◽  
Infection Model ◽  
Screening Assay ◽  
Antibiotic Development ◽  
Thiamine Biosynthesis

Thiamine pyrophosphate (TPP) is an essential cofactor for various pivotal cellular processes in all living organisms, including bacteria. Thiamine biosynthesis occurs in bacteria but not in humans; therefore, the enzymes in this pathway are attractive targets for antibiotic development. Among these enzymes, thiamine monophosphate kinase (ThiL) catalyzes the final step of this pathway, phosphorylating thiamine monophosphate to produce TPP. Here, we extensively investigated ThiL in Pseudomonas aeruginosa, a major pathogen responsible for hospital-acquired infections. We demonstrate that thiL deletion abolishes not only thiamine biosynthesis but also thiamine salvage capability and results in growth defects of the ΔthiL strain even in the presence of thiamine derivatives, except for TPP. Most importantly, the pathogenesis of the ΔthiL strain was markedly attenuated, compared with that of WT cells, with lower inflammatory cytokine induction and 103–104-fold decreased bacterial loads in an in vivo infection model in which the intracellular TPP level was in the submicromolar range. To validate P. aeruginosa ThiL (PaThiL) as a drug target, we further characterized its biochemical properties, determining a Vmax of 4.0 ± 0.2 nmol·min−1 and Km values of 111 ± 8 and 8.0 ± 3.5 μm for ATP and thiamine monophosphate, respectively. An in vitro small-molecule screening assay identified PaThiL inhibitors including WAY213613, a noncompetitive inhibitor with a Ki value of 13.4 ± 2.3 μm and potential antibacterial activity against P. aeruginosa. These comprehensive biological and biochemical results indicate that PaThiL represents a potential drug target for the development of an augmented repertoire of antibiotics against P. aeruginosa.

scholarly journals Synergistic Activity of Berberine with Azithromycin against Pseudomonas Aeruginosa Isolated from Patients with Cystic Fibrosis of Lung In Vitro and In Vivo

2017 ◽  
Vol 42 (4) ◽  
pp. 1657-1669 ◽  
Author(s):  
YongTao Li ◽  
JianRong Huang ◽  
LanJuan Li ◽  
LinSheng Liu
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Lung Infection ◽  
Extracellular Dna ◽  
Pcr Analysis ◽  
Infection Model ◽  
Synergistic Activity ◽  
Time Kill

Background/Aims: Pseudomonas aeruginosa (PA) is one of the major opportunistic pathogens which can cause chronic lung infection of cystic fibrosis (CF). The formation of PA biofilm promotes CF development and restricts the antimicrobial efficacies of current antibiotics. Methods: The antimicrobial effects of azithromycin (AZM) and berberine (BER) alone and in combination were evaluated using microdilution method, checkerboard assay, time-kill test, qRT-PCR analysis and absorption method. The treatments of AZM and/or BER were further evaluated in an animal lung infection model via observing survival rate, bacterial burden and histopathology of lung, the levels of pro-/anti-inflammatory cytokines. Results: AZM-BER were demonstrated to be synergistic against ten clinical PA isolates as well as the standard reference PA ATCC27853, in which PA03 was the most susceptible isolate to AZM-BER with FICI of 0.13 and chosen for subsequent experiments. The synergism of AZM-BER was further confirmed against PA03 in time-kill test and scanning electron microscope (SEM) at their concentrations showing synergism. In PA03, we found that AZM-BER could significantly attenuate productions of a series of virulence factors including alginate, LasA protease, LasB protease, pyoverdin, pyocyanin, chitinase as well as extracellular DNA, and remarkably inhibit the levels of quorum sensing (QS) molecules and the expressions of lasI, lasR, rhlI, rhlR at 1/2×MIC, 1×MIC and 2×MIC. In the infection model, the mice survival were increased markedly, the inflammations of infected lungs were improved greatly along with reduced IL-6, IL-8 and ascended IL-10 at 0.8 mg/kg of AZM combined with 3.2 mg/kg of BER. Conclusion: BER might be a promising synergist to enhance the antimicrobial activity of AZM in vitro and in vivo.

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