scholarly journals Carbapenem-Resistant Klebsiella pneumoniae Clinical Isolates: In Vivo Virulence Assessment in Galleria mellonella and Potential Therapeutics by Polycationic Oligoethyleneimine

Antibiotics ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 56
Author(s):  
Dalila Mil-Homens ◽  
Maria Martins ◽  
José Barbosa ◽  
Gabriel Serafim ◽  
Maria J. Sarmento ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Galleria Mellonella ◽  
Multidrug Resistant ◽  
In Vitro Models ◽  
Clinical Isolates ◽  
In Vivo Model ◽  
Virulence Potential ◽  
Hospital Acquired

Klebsiella pneumoniae, one of the most common pathogens found in hospital-acquired infections, is often resistant to multiple antibiotics. In fact, multidrug-resistant (MDR) K. pneumoniae producing KPC or OXA-48-like carbapenemases are recognized as a serious global health threat. In this sense, we evaluated the virulence of K. pneumoniae KPC(+) or OXA-48(+) aiming at potential antimicrobial therapeutics. K. pneumoniae carbapenemase (KPC) and the expanded-spectrum oxacillinase OXA-48 isolates were obtained from patients treated in medical care units in Lisbon, Portugal. The virulence potential of the K. pneumonia clinical isolates was tested using the Galleria mellonella model. For that, G. mellonella larvae were inoculated using patients KPC(+) and OXA-48(+) isolates. Using this in vivo model, the KPC(+) K. pneumoniae isolates showed to be, on average, more virulent than OXA-48(+). Virulence was found attenuated when a low bacterial inoculum (one magnitude lower) was tested. In addition, we also report the use of a synthetic polycationic oligomer (L-OEI-h) as a potential antimicrobial agent to fight infectious diseases caused by MDR bacteria. L-OEI-h has a broad-spectrum antibacterial activity and exerts a significantly bactericidal activity within the first 5-30 min treatment, causing lysis of the cytoplasmic membrane. Importantly, the polycationic oligomer showed low toxicity against in vitro models and no visible cytotoxicity (measured by survival and health index) was noted on the in vivo model (G. mellonella), thus L-OEI-h is foreseen as a promising polymer therapeutic for the treatment of MDR K. pneumoniae infections.

Exploring Galleria mellonella larval model to evaluate antibacterial efficacy of Cecropin A (1-7)- Melittin against multi-drug resistant enteroaggregative Escherichia coli

2021 ◽  
Author(s):  
Jess Vergis ◽  
S V S Malik ◽  
Richa Pathak ◽  
Manesh Kumar ◽  
Nitin V Kurkure ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Galleria Mellonella ◽  
In Vivo Model ◽  
Drug Resistant ◽  
Physiological Concentration ◽  
Microbial Drug Resistance ◽  
Cecropin A ◽  
Screening And Identification

Abstract High throughput in vivo laboratory models is need for screening and identification of effective therapeutic agents to overcome microbial drug-resistance. This study was undertaken to evaluate in vivo antimicrobial efficacy of short-chain antimicrobial peptide- Cecropin A (1–7)-Melittin (CAMA) against three multi- drug resistant enteroaggregative Escherichia coli (MDR-EAEC) field isolates in a Galleria mellonella larval model. The minimum inhibitory concentration (MIC; 2.0 mg/L) and minimum bactericidal concentration (MBC; 4.0 mg/L) of CAMA were determined by microdilution assay. CAMA was found to be stable at high temperatures, physiological concentration of cationic salts and proteases; safe with sheep erythrocytes, secondary cell lines and commensal lactobacilli at lower MICs; and exhibited membrane permeabilisation. In vitro time-kill assay revealed concentration- and time-dependent clearance of MDR-EAEC in CAMA-treated groups at 30 min. CAMA- treated G. mellonella larvae exhibited an increased survival rate, reduced MDR-EAEC counts, immunomodulatory effect and proved non-toxic which concurred with histopathological findings. CAMA exhibited either an equal or better efficacy than the tested antibiotic control, meropenem. This study highlights the possibility of G. mellonella larvae as an excellent in vivo model for investigating the host-pathogen interaction, including the efficacy of antimicrobials against MDR-EAEC strains.

Emergence of ceftazidime/avibactam resistance in KPC-3-producing Klebsiella pneumoniae in vivo

2019 ◽  
Vol 74 (11) ◽  
pp. 3211-3216 ◽  
Author(s):  
Stephan Göttig ◽  
Denia Frank ◽  
Eleonora Mungo ◽  
Anika Nolte ◽  
Michael Hogardt ◽  
...  
Keyword(s):  
Combination Therapy ◽  
Klebsiella Pneumoniae ◽  
Selection Pressure ◽  
Galleria Mellonella ◽  
Phenotypic Characterization ◽  
Infection Model ◽  
Development Of Resistance ◽  
Time Kill

Abstract Objectives The β-lactam/β-lactamase inhibitor combination ceftazidime/avibactam is active against KPC-producing Enterobacterales. Herein, we present molecular and phenotypic characterization of ceftazidime/avibactam resistance in KPC-3-producing Klebsiella pneumoniae that emerged in vivo and in vitro. Methods Sequence analysis of blaKPC-3 was performed from clinical and in vitro-generated ceftazidime/avibactam-resistant K. pneumoniae isolates. Time–kill kinetics and the Galleria mellonella infection model were applied to evaluate the activity of ceftazidime/avibactam and imipenem alone and in combination. Results The ceftazidime/avibactam-resistant clinical K. pneumoniae isolate revealed the amino acid change D179Y in KPC-3. Sixteen novel mutational changes in KPC-3 among in vitro-selected ceftazidime/avibactam-resistant isolates were described. Time–kill kinetics showed the emergence of a resistant subpopulation under selection pressure with either imipenem or ceftazidime/avibactam. However, combined selection pressure with imipenem plus ceftazidime/avibactam prevented the development of resistance and resulted in bactericidal activity. Concordantly, the G. mellonella infection model revealed that monotherapy with ceftazidime/avibactam is prone to select for resistance in vivo and that combination therapy with imipenem results in significantly better survival. Conclusions Ceftazidime/avibactam is a valuable antibiotic against MDR and carbapenem-resistant Enterobacterales. Based on time–kill kinetics as well as an in vivo infection model we postulate a combination therapy of ceftazidime/avibactam and imipenem as a strategy to prevent the development of ceftazidime/avibactam resistance in KPC-producing Enterobacterales in vivo.

scholarly journals C3 Promotes Clearance of Klebsiella pneumoniae by A549 Epithelial Cells

2004 ◽  
Vol 72 (3) ◽  
pp. 1767-1774 ◽  
Author(s):  
Beatriz de Astorza ◽  
Guadalupe Cortés ◽  
Catalina Crespí ◽  
Carles Saus ◽  
José María Rojo ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Klebsiella Pneumoniae ◽  
Alveolar Epithelial Cells ◽  
Clinical Isolates ◽  
Complement Components ◽  
Innate Defense ◽  
Alveolar Epithelial

ABSTRACT The airway epithelium represents a primary site for contact between microbes and their hosts. To assess the role of complement in this event, we studied the interaction between the A549 cell line derived from human alveolar epithelial cells and a major nosocomial pathogen, Klebsiella pneumoniae, in the presence of serum. In vitro, we found that C3 opsonization of poorly encapsulated K. pneumoniae clinical isolates and an unencapsulated mutant enhanced dramatically bacterial internalization by A549 epithelial cells compared to highly encapsulated clinical isolates. Local complement components (either present in the human bronchoalveolar lavage or produced by A549 epithelial cells) were sufficient to opsonize K. pneumoniae. CD46 could competitively inhibit the internalization of K. pneumoniae by the epithelial cells, suggesting that CD46 is a receptor for the binding of complement-opsonized K. pneumoniae to these cells. We observed that poorly encapsulated strains appeared into the alveolar epithelial cells in vivo but that (by contrast) they were completely avirulent in a mouse model of pneumonia compared to the highly encapsulated strains. Our results show that bacterial opsonization by complement enhances the internalization of the avirulent microorganisms by nonphagocytic cells such as A549 epithelial cells and allows an efficient innate defense.

scholarly journals Lignans from Bursera fagaroides Affect In Vivo Cell Behavior by Disturbing the Tubulin Cytoskeleton in Zebrafish Embryos

Molecules ◽  
2018 ◽  
Vol 24 (1) ◽  
pp. 8 ◽  
Author(s):  
Mayra Antúnez-Mojica ◽  
Andrés Rojas-Sepúlveda ◽  
Mario Mendieta-Serrano ◽  
Leticia Gonzalez-Maya ◽  
Silvia Marquina ◽  
...  
Keyword(s):  
Cell Migration ◽  
Biological Effects ◽  
In Vitro Models ◽  
In Vivo Model ◽  
Zebrafish Embryos ◽  
Microtubule Cytoskeleton ◽  
Zebrafish Model ◽  
Bioassay Guided Fractionation

By using a zebrafish embryo model to guide the chromatographic fractionation of antimitotic secondary metabolites, seven podophyllotoxin-type lignans were isolated from a hydroalcoholic extract obtained from the steam bark of Bursera fagaroides. The compounds were identified as podophyllotoxin (1), β-peltatin-A-methylether (2), 5′-desmethoxy-β-peltatin-A-methylether (3), desmethoxy-yatein (4), desoxypodophyllotoxin (5), burseranin (6), and acetyl podophyllotoxin (7). The biological effects on mitosis, cell migration, and microtubule cytoskeleton remodeling of lignans 1–7 were further evaluated in zebrafish embryos by whole-mount immunolocalization of the mitotic marker phospho-histone H3 and by a tubulin antibody. We found that lignans 1, 2, 4, and 7 induced mitotic arrest, delayed cell migration, and disrupted the microtubule cytoskeleton in zebrafish embryos. Furthermore, microtubule cytoskeleton destabilization was observed also in PC3 cells, except for 7. Therefore, these results demonstrate that the cytotoxic activity of 1, 2, and 4 is mediated by their microtubule-destabilizing activity. In general, the in vivo and in vitro models here used displayed equivalent mitotic effects, which allows us to conclude that the zebrafish model can be a fast and cheap in vivo model that can be used to identify antimitotic natural products through bioassay-guided fractionation.

scholarly journals Macrocolony of NDM-1 Producing Enterobacter hormaechei subsp. oharae Generates Subpopulations with Different Features Regarding the Response of Antimicrobial Agents and Biofilm Formation

Pathogens ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 49 ◽  
Author(s):  
Flávia Roberta Brust ◽  
Luana Boff ◽  
Danielle da Silva Trentin ◽  
Franciele Pedrotti Rozales ◽  
Afonso Luís Barth ◽  
...  
Keyword(s):  
Antimicrobial Agents ◽  
Galleria Mellonella ◽  
Polymyxin B ◽  
Multidrug Resistant ◽  
Biofilm Production ◽  
Depth Study ◽  
Enterobacter Hormaechei ◽  
Type 3

Enterobacter cloacae complex has been increasingly recognized as a nosocomial pathogen representing the third major Enterobacteriaceae species involved with infections. This study aims to evaluate virulence and antimicrobial susceptibility of subpopulations generated from macrocolonies of NDM-1 producing Enterobacter hormaechei clinical isolates. Biofilm was quantified using crystal violet method and fimbrial genes were investigated by PCR. Susceptibility of antimicrobials, alone and combined, was determined by minimum inhibitory concentration and checkerboard assays, respectively. Virulence and efficacy of antimicrobials were evaluated in Galleria mellonella larvae. Importantly, we verified that some subpopulations that originate from the same macrocolony present different biofilm production ability and distinct susceptibility to meropenem due to the loss of blaNDM-1 encoding plasmid. A more in-depth study was performed with the 798 macrocolony subpopulations. Type 3 fimbriae were straightly related with biofilm production; however, virulence in larvae was not statistically different among subpopulations. Triple combination with meropenem–rifampicin–polymyxin B showed in vitro synergistic effect against all subpopulations; while in vivo this treatment showed different efficacy rates for 798-1S and 798-4S subpopulations. The ability of multidrug resistant E. hormaechei isolates in generating bacterial subpopulations presenting different susceptible and virulence mechanisms are worrisome and may explain why these infections are hardly overcome.

scholarly journals Fluopsin C for Treating Multidrug-Resistant Infections: In vitro Activity Against Clinically Important Strains and in vivo Efficacy Against Carbapenemase-Producing Klebsiella pneumoniae

2019 ◽  
Vol 10 ◽  
Author(s):  
Miguel Octavio Pérez Navarro ◽  
Ane Stefano Simionato ◽  
Juan Carlos Bedoya Pérez ◽  
André Riedi Barazetti ◽  
Janaina Emiliano ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Multidrug Resistant ◽  
Vitro Activity ◽  
In Vitro Activity ◽  
In Vivo Efficacy

scholarly journals Design of Epitope-Based Peptide Vaccine against Pseudomonas aeruginosa Fructose Bisphosphate Aldolase Protein Using Immunoinformatics

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Mustafa Elhag ◽  
Ruaa Mohamed Alaagib ◽  
Nagla Mohamed Ahmed ◽  
Mustafa Abubaker ◽  
Esraa Musa Haroun ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Peptide Vaccine ◽  
Multidrug Resistant ◽  
Fructose Bisphosphate ◽  
Mhc I ◽  
Mhc Ii ◽  
Fructose Bisphosphate Aldolase ◽  
Hospital Acquired

Pseudomonas aeruginosa is a common pathogen that is responsible for serious hospital-acquired infections, ventilator-associated pneumonia, and various sepsis syndromes. Also, it is a multidrug-resistant pathogen recognized for its ubiquity and its intrinsically advanced antibiotic-resistant mechanisms. It usually affects immunocompromised individuals but can also infect immunocompetent individuals. There is no vaccine against it available till now. This study predicts an effective epitope-based vaccine against fructose bisphosphate aldolase (FBA) of Pseudomonas aeruginosa using immunoinformatics tools. The protein sequences were obtained from NCBI, and prediction tests were undertaken to analyze possible epitopes for B and T cells. Three B cell epitopes passed the antigenicity, accessibility, and hydrophilicity tests. Six MHC I epitopes were found to be promising, while four MHC II epitopes were found promising from the result set. Nineteen epitopes were shared between MHC I and II results. For the population coverage, the epitopes covered 95.62% worldwide excluding certain MHC II alleles. We recommend in vivo and in vitro studies to prove its effectiveness.

Experimental Migraine Models and Their Relevance in Migraine Therapy

Cephalalgia ◽  
2006 ◽  
Vol 26 (6) ◽  
pp. 642-659 ◽  
Author(s):  
U Arulmani ◽  
S Gupta ◽  
A Maassen VanDenBrink ◽  
D Centurión ◽  
CM Villalón ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Trigeminal Ganglion ◽  
In Vitro Models ◽  
In Vivo Model ◽  
Trigeminal System ◽  
Sagittal Sinus ◽  
Migraine Pathophysiology ◽  
Stimulation Of

Although the understanding of migraine pathophysiology is incomplete, it is now well accepted that this neurovascular syndrome is mainly due to a cranial vasodilation with activation of the trigeminal system. Several experimental migraine models, based on vascular and neuronal involvement, have been developed. Obviously, the migraine models do not entail all facets of this clinically heterogeneous disorder, but their contribution at several levels (molecular, in vitro, in vivo) has been crucial in the development of novel antimigraine drugs and in the understanding of migraine pathophysiology. One important vascular in vivo model, based on an assumption that migraine headache involves cranial vasodilation, determines porcine arteriovenous anastomotic blood flow. Other models utilize electrical stimulation of the trigeminal ganglion/nerve to study neurogenic dural inflammation, while the superior sagittal sinus stimulation model takes into account the transmission of trigeminal nociceptive input in the brainstem. More recently, the introduction of integrated models, namely electrical stimulation of the trigeminal ganglion or systemic administration of capsaicin, allows studying the activation of the trigeminal system and its effect on the cranial vasculature. Studies using in vitro models have contributed enormously during the preclinical stage to characterizing the receptors in cranial blood vessels and to studying the effects of several putative antimigraine agents. The aforementioned migraine models have advantages as well as some limitations. The present review is devoted to discussing various migraine models and their relevance to antimigraine therapy.

scholarly journals Polymyxin Triple Combinations against Polymyxin-Resistant, Multidrug-Resistant, KPC-Producing Klebsiella pneumoniae

2020 ◽  
Vol 64 (8) ◽  
Author(s):  
Su Mon Aye ◽  
Irene Galani ◽  
Heidi Yu ◽  
Jiping Wang ◽  
Ke Chen ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Triple Therapy ◽  
Polymyxin B ◽  
Multidrug Resistant ◽  
Infection Model ◽  
Bacterial Killing ◽  
Standard Dosage ◽  
Time Kill

ABSTRACT Resistance to polymyxin antibiotics is increasing. Without new antibiotic classes, combination therapy is often required. We systematically investigated bacterial killing with polymyxin-based combinations against multidrug-resistant (including polymyxin-resistant), carbapenemase-producing Klebsiella pneumoniae. Monotherapies and double- and triple-combination therapies were compared to identify the most efficacious treatment using static time-kill studies (24 h, six isolates), an in vitro pharmacokinetic/pharmacodynamic model (IVM; 48 h, two isolates), and the mouse thigh infection model (24 h, six isolates). In static time-kill studies, all monotherapies (polymyxin B, rifampin, amikacin, meropenem, or minocycline) were ineffective. Initial bacterial killing was enhanced with various polymyxin B-containing double combinations; however, substantial regrowth occurred in most cases by 24 h. Most polymyxin B-containing triple combinations provided greater and more sustained killing than double combinations. Standard dosage regimens of polymyxin B (2.5 mg/kg of body weight/day), rifampin (600 mg every 12 h), and amikacin (7.5 mg/kg every 12 h) were simulated in the IVM. Against isolate ATH 16, no viable bacteria were detected across 5 to 25 h with triple therapy, with regrowth to ∼2-log10 CFU/ml occurring at 48 h. Against isolate BD 32, rapid initial killing of ∼3.5-log10 CFU/ml at 5 h was followed by a slow decline to ∼2-log10 CFU/ml at 48 h. In infected mice, polymyxin B monotherapy (60 mg/kg/day) generally was ineffective. With triple therapy (polymyxin B at 60 mg/kg/day, rifampin at 120 mg/kg/day, and amikacin at 300 mg/kg/day), at 24 h there was an ∼1.7-log10 CFU/thigh reduction compared to the starting inoculum for all six isolates. Our results demonstrate that the polymyxin B-rifampin-amikacin combination significantly enhanced in vitro and in vivo bacterial killing, providing important information for the optimization of polymyxin-based combinations in patients.

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