scholarly journals Inhaled bacteriophage therapy in a porcine model of ventilator-associated pneumonia caused by pseudomonas aeruginosa.

2021 ◽  
Author(s):  
Antoine Guillon ◽  
Jeoffrey Pardessus ◽  
Guillaume L’Hostis ◽  
Cindy Fevre ◽  
Celine Barc ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Pseudomonas Aeruginosa ◽  
Phage Therapy ◽  
Antimicrobial Efficacy ◽  
Resistant Bacteria ◽  
Ventilator Associated Pneumonia ◽  
Bacteriophage Therapy ◽  
Log Reduction

Background and Purpose. Pseudomonas aeruginosa is a main cause of ventilator-associated pneumonia (VAP) with drug-resistant bacteria. Bacteriophage therapy has experienced resurgence to compensate for the limited development of novel antibiotics. However, phage therapy is limited to a compassionate use so far, resulting from lack of adequate studies in relevant pharmacological models. We used a pig model of VAP caused by P. aeruginosa that recapitulates essential features of human disease to study the antimicrobial efficacy of nebulized-phage therapy. Experimental Approach. (i) Lysis kinetic assays were performed to evaluate in vitro phage antibacterial efficacy against P. aeruginosa and select relevant combinations of lytic phages. (ii) The efficacy of the phage combinations was investigated in vivo (murine model of P. aeruginosa lung infection). (iii) We determined the optimal conditions to ensure efficient phage delivery by aerosol during mechanical ventilation. (iv) Lung antimicrobial efficacy of inhaled-phage therapy was evaluated in pigs, which were anesthetized, mechanically ventilated and infected with P. aeruginosa. Key Results. By selecting an active phage cocktail and optimizing aerosol delivery conditions, we were able to deliver high phage concentrations in the lungs, which resulted in a rapid and marked reduction in P. aeruginosa density (1.5 Log reduction, p<0.001). No phage was detected in the sera and urines throughout the experiment. Conclusion and Implications. Our findings demonstrated: (i) the feasibility of delivering large amounts of active phages by nebulization during mechanical ventilation, (ii) rapid control of in situ infection by inhaled bacteriophage in an experimental model of VAP with high translational value.

scholarly journals Pseudomonas aeruginosa PAO 1 In Vitro Time–Kill Kinetics Using Single Phages and Phage Formulations—Modulating Death, Adaptation, and Resistance

Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 877
Author(s):  
Ana Mafalda Pinto ◽  
Alberta Faustino ◽  
Lorenzo M. Pastrana ◽  
Manuel Bañobre-López ◽  
Sanna Sillankorva
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Phage Therapy ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Chronic Infections ◽  
Swarming Motility ◽  
Resistance Development ◽  
Healthcare Settings ◽  
Time Kill

Pseudomonas aeruginosa is responsible for nosocomial and chronic infections in healthcare settings. The major challenge in treating P. aeruginosa-related diseases is its remarkable capacity for antibiotic resistance development. Bacteriophage (phage) therapy is regarded as a possible alternative that has, for years, attracted attention for fighting multidrug-resistant infections. In this work, we characterized five phages showing different lytic spectrums towards clinical isolates. Two of these phages were isolated from the Russian Microgen Sextaphage formulation and belong to the Phikmvviruses, while three Pbunaviruses were isolated from sewage. Different phage formulations for the treatment of P. aeruginosa PAO1 resulted in diversified time–kill outcomes. The best result was obtained with a formulation with all phages, prompting a lower frequency of resistant variants and considerable alterations in cell motility, resulting in a loss of 73.7% in swimming motility and a 79% change in swarming motility. These alterations diminished the virulence of the phage-resisting phenotypes but promoted their growth since most became insensitive to a single or even all phages. However, not all combinations drove to enhanced cell killings due to the competition and loss of receptors. This study highlights that more caution is needed when developing cocktail formulations to maximize phage therapy efficacy. Selecting phages for formulations should consider the emergence of phage-resistant bacteria and whether the formulations are intended for short-term or extended antibacterial application.

scholarly journals Phage steering of antibiotic-resistance evolution in the bacterial pathogen, Pseudomonas aeruginosa

2020 ◽  
Vol 2020 (1) ◽  
pp. 148-157 ◽  
Author(s):  
James Gurney ◽  
Léa Pradier ◽  
Joanne S Griffin ◽  
Claire Gougat-Barbera ◽  
Benjamin K Chan ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Resistance ◽  
Bacterial Pathogen ◽  
Antibiotic Sensitivity ◽  
Resistant Bacteria ◽  
Phage Resistance ◽  
Antibiotic Resistant ◽  
Trade Off

Abstract Background and objectives Antimicrobial resistance is a growing global concern and has spurred increasing efforts to find alternative therapeutics. Bacteriophage therapy has seen near constant use in Eastern Europe since its discovery over a century ago. One promising approach is to use phages that not only reduce bacterial pathogen loads but also select for phage resistance mechanisms that trade-off with antibiotic resistance—so called ‘phage steering’. Methodology Recent work has shown that the phage OMKO1 can interact with efflux pumps and in so doing select for both phage resistance and antibiotic sensitivity of the pathogenic bacterium Pseudomonas aeruginosa. We tested the robustness of this approach to three different antibiotics in vitro (tetracycline, erythromycin and ciprofloxacin) and one in vivo (erythromycin). Results We show that in vitro OMKO1 can reduce antibiotic resistance of P. aeruginosa (Washington PAO1) even in the presence of antibiotics, an effect still detectable after ca.70 bacterial generations in continuous culture with phage. Our in vivo experiment showed that phage both increased the survival times of wax moth larvae (Galleria mellonella) and increased bacterial sensitivity to erythromycin. This increased antibiotic sensitivity occurred both in lines with and without the antibiotic. Conclusions and implications Our study supports a trade-off between antibiotic resistance and phage sensitivity. This trade-off was maintained over co-evolutionary time scales even under combined phage and antibiotic pressure. Similarly, OMKO1 maintained this trade-off in vivo, again under dual phage/antibiotic pressure. Our findings have implications for the future clinical use of steering in phage therapies. Lay Summary: Given the rise of antibiotic-resistant bacterial infection, new approaches to treatment are urgently needed. Bacteriophages (phages) are bacterial viruses. The use of such viruses to treat infections has been in near-continuous use in several countries since the early 1900s. Recent developments have shown that these viruses are not only effective against routine infections but can also target antibiotic resistant bacteria in a novel, unexpected way. Similar to other lytic phages, these so-called ‘steering phages’ kill the majority of bacteria directly. However, steering phages also leave behind bacterial variants that resist the phages, but are now sensitive to antibiotics. Treatment combinations of these phages and antibiotics can now be used to greater effect than either one independently. We evaluated the impact of steering using phage OMKO1 and a panel of three antibiotics on Pseudomonas aeruginosa, an important pathogen in hospital settings and in people with cystic fibrosis. Our findings indicate that OMKO1, either alone or in combination with antibiotics, maintains antibiotic sensitivity both in vitro and in vivo, giving hope that phage steering will be an effective treatment option against antibiotic-resistant bacteria.

scholarly journals Synergistic Efficacy of Aedes aegypti Antimicrobial Peptide Cecropin A2 and Tetracycline against Pseudomonas aeruginosa

2017 ◽  
Vol 61 (7) ◽  
Author(s):  
Zhaojun Zheng ◽  
Nagendran Tharmalingam ◽  
Qingzhong Liu ◽  
Elamparithi Jayamani ◽  
Wooseong Kim ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Aedes Aegypti ◽  
Mammalian Cells ◽  
Galleria Mellonella ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Synergistic Activity ◽  
Content Type

ABSTRACT The increasing prevalence of antibiotic resistance has created an urgent need for alternative drugs with new mechanisms of action. Antimicrobial peptides (AMPs) are promising candidates that could address the spread of multidrug-resistant bacteria, either alone or in combination with conventional antibiotics. We studied the antimicrobial efficacy and bactericidal mechanism of cecropin A2, a 36-residue α-helical cationic peptide derived from Aedes aegypti cecropin A, focusing on the common pathogen Pseudomonas aeruginosa. The peptide showed little hemolytic activity and toxicity toward mammalian cells, and the MICs against most clinical P. aeruginosa isolates were 32 to 64 μg/ml, and its MICs versus other Gram-negative bacteria were 2 to 32 μg/ml. Importantly, cecropin A2 demonstrated synergistic activity against P. aeruginosa when combined with tetracycline, reducing the MICs of both agents by 8-fold. The combination was also effective in vivo in the P. aeruginosa/Galleria mellonella model (P < 0.001). We found that cecropin A2 bound to P. aeruginosa lipopolysaccharides, permeabilized the membrane, and interacted with the bacterial genomic DNA, thus facilitating the translocation of tetracycline into the cytoplasm. In summary, the combination of cecropin A2 and tetracycline demonstrated synergistic antibacterial activity against P. aeruginosa in vitro and in vivo, offering an alternative approach for the treatment of P. aeruginosa infections.

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 &gt;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 Priming with intranasal lactobacilli prevents Pseudomonas aeruginosa acute pneumonia in mice.

2020 ◽  
Author(s):  
Marie-Sarah FANGOUS ◽  
Philippe Gosset ◽  
Nicolas Galakhoff ◽  
Stéphanie Gouriou ◽  
Charles-Antoine Guilloux ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Virulence Factors ◽  
Saline Solution ◽  
Clinical Isolates ◽  
Control Groups ◽  
Strain Pao1 ◽  
Log Reduction ◽  
Animal Survival

Abstract Background : Increasing resistance to antibiotics of Pseudomonas aeruginosa leads to therapeutic deadlock and alternative therapies are needed. We aimed to evaluate the effects of Lactobacillus clinical isolates in vivo, through intranasal administration on a murine model of Pseudomonas aeruginosa pneumonia.Results : We screened in vitro 50 pulmonary clinical isolates of Lactobacillus for their ability to decrease the synthesis of two QS dependent-virulence factors (elastase and pyocyanin) produced by Pseudomonas aeruginosa strain PAO1.Two blends of three Lactobacillus isolates were then tested in vivo: one with highly effective anti-PAO1 virulence factors properties (blend named L.rff for L. rhamnosus, two L. fermentum strains), and the second with no properties (blend named L.psb, for L. paracasei, L. salivarius and L. brevis). Each blend was administered intranasally to mice 18h prior to PAO1 pulmonary infection. Animal survival, bacterial loads, cytological analysis, and cytokines secretion in the lungs were evaluated at 6 or 24h post infection with PAO1. Intranasal priming with both lactobacilli blends significantly improved 7-day mice survival from 12% for the control PAO1 group to 71% and 100% for the two groups receiving L.rff and L.psb respectively. No mortality was observed for both control groups receiving either L.rff or L.psb. Additionally, the PAO1 lung clearance was significantly enhanced at 24h. A 2-log and 4-log reduction was observed in the L.rff+PAO1 and L.psb+PAO1 groups respectively, compared to the control PAO1 group. Significant reductions in neutrophil recruitment and proinflammatory cytokine and chemokine secretion were observed after lactobacilli administration compared to saline solution, whereas IL-10 production was increased. Conclusions : These results demonstrate that intranasal priming with lactobacilli acts as a prophylaxis, and avoids fatal complications caused by Pseudomonas aeruginosa pneumonia in mice. These results were independent of in vitro anti-Pseudomonas aeruginosa activity on QS-dependent virulence factors. Further experiments are required to identify the immune mechanism before initiating clinical trials.

scholarly journals Novel Lytic Phages Protect Cells and Mice against Pseudomonas aeruginosa Infection

2021 ◽  
Author(s):  
Feng Chen ◽  
Xingjun Cheng ◽  
Jianbo Li ◽  
Xiefang Yuan ◽  
Xiuhua Huang ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Mouse Models ◽  
Bacterial Infections ◽  
Phage Therapy ◽  
Inflammatory Responses ◽  
Multi Drug Resistance ◽  
Bacterial Strains ◽  
Genetic Traits

With the fast emergence of serious antibiotic resistance and the lagged discovery of novel antibacterial drugs, phage therapy for pathogenic bacterial infections has acquired great attention in the clinics. However, development of therapeutic phages also faces tough challenges, such as laborious screening and time to generate effective phage drugs since each phage may only lyse a narrow scope of bacterial strains. Identifying highly effective phages with broad host ranges is crucial for improving phage therapy. Here, we isolated and characterized several lytic phages from various environments specific for Pseudomonas aeruginosa by testing their growth, invasion, host ranges, and potential for killing targeted bacteria. Importantly, we identified several therapeutic phages (HX1, PPY9, and TH15) with broad host ranges to lyse laboratory strains and clinical isolates of P. aeruginosa with multi-drug resistance (MDR) both in vitro and in mouse models. In addition, we analyzed critical genetic traits related to the high-level broad host coverages by genome sequencing and subsequent computational analysis against known phages. Collectively, our findings establish that these novel phages may have potential for further development as therapeutic options for patients who fail to respond to conventional treatments. IMPORTANCE Novel lytic phages isolated from various environmental settings were systematically characterized for their critical genetic traits, morphology structures, host ranges against laboratory strains and clinical multi-drug resistant (MDR) Pseudomonas aeruginosa, and antibacterial capacity both in vitro and in mouse models. First, we characterized the genetic traits and compared with other existing phages. Furthermore, we utilized acute pneumonia induced by laboratorial strain PAO1, and W19, an MDR clinical isolate and chronic pneumonia by agar beads laden with FDR1, a mucoid phenotype strain isolated from the sputum of a cystic fibrosis (CF) patient. Consequently, we found that these phages not only suppress bacteria in vitro but also significantly reduce the infection symptom and disease progression in vivo, including lowered bug burdens, inflammatory responses and lung injury in mice, suggesting that they may be further developed as therapeutic agents against MDR P. aeruginosa.

scholarly journals Bacteriophage therapy against Pseudomonas aeruginosa biofilms: a review

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Zahra Chegini ◽  
Amin Khoshbayan ◽  
Majid Taati Moghadam ◽  
Iman Farahani ◽  
Parham Jazireian ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Phage Therapy ◽  
Bacteriophage Therapy ◽  
Antibiotic Resistant ◽  
Combined Use ◽  
Biofilm Destruction ◽  
Limited Host Range ◽  
The One

Abstract Multi-Drug Resistant (MDR) Pseudomonas aeruginosa is one of the most important bacterial pathogens that causes infection with a high mortality rate due to resistance to different antibiotics. This bacterium prompts extensive tissue damage with varying factors of virulence, and its biofilm production causes chronic and antibiotic-resistant infections. Therefore, due to the non-applicability of antibiotics for the destruction of P. aeruginosa biofilm, alternative approaches have been considered by researchers, and phage therapy is one of these new therapeutic solutions. Bacteriophages can be used to eradicate P. aeruginosa biofilm by destroying the extracellular matrix, increasing the permeability of antibiotics into the inner layer of biofilm, and inhibiting its formation by stopping the quorum-sensing activity. Furthermore, the combined use of bacteriophages and other compounds with anti-biofilm properties such as nanoparticles, enzymes, and natural products can be of more interest because they invade the biofilm by various mechanisms and can be more effective than the one used alone. On the other hand, the use of bacteriophages for biofilm destruction has some limitations such as limited host range, high-density biofilm, sub-populate phage resistance in biofilm, and inhibition of phage infection via quorum sensing in biofilm. Therefore, in this review, we specifically discuss the use of phage therapy for inhibition of P. aeruginosa biofilm in clinical and in vitro studies to identify different aspects of this treatment for broader use.

scholarly journals Phage Selective Pressure Reduces Virulence of Hypervirulent Klebsiella pneumoniae Through Mutation of the wzc Gene

2021 ◽  
Vol 12 ◽  
Author(s):  
Lingjie Song ◽  
Xianggui Yang ◽  
Jinwei Huang ◽  
Xiaokui Zhu ◽  
Guohui Han ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Genomic Analysis ◽  
Resistant Bacteria ◽  
Comparative Genomic ◽  
Wild Type ◽  
Bacteriophage Therapy ◽  
Deletion Mutations ◽  
Invasive Infections

Hypervirulent Klebsiella pneumoniae (hvKp), one of the major community-acquired pathogens, can cause invasive infections such as liver abscess. In recent years, bacteriophages have been used in the treatment of K. pneumoniae, but the characteristics of the phage-resistant bacteria produced in the process of phage therapy need to be evaluated. In this study, two Podoviridae phages, hvKpP1 and hvKpP2, were isolated and characterized. In vitro and in vivo experiments demonstrated that the virulence of the resistant bacteria was significantly reduced compared with that of the wild type. Comparative genomic analysis of monoclonal sequencing showed that nucleotide deletion mutations of wzc and wcaJ genes led to phage resistance, and the electron microscopy and mucoviscosity results showed that mutations led to the loss of the capsule. Meanwhile, animal assay indicated that loss of capsule reduced the virulence of hvKp. These findings contribute to a better understanding of bacteriophage therapy, which not only can kill bacteria directly but also can reduce the virulence of bacteria by phage screening.

scholarly journals Parallel evolution of phage resistance - virulence trade - offs during in vitro and nasal Pseudomonas aeruginosa phage treatment

2021 ◽  
Author(s):  
Meaghan Castledine ◽  
Daniel Padfield ◽  
Pawel Sierocinski ◽  
Jesica Soria Pascual ◽  
Adam Hughes ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Evolutionary Dynamics ◽  
Phage Therapy ◽  
De Novo ◽  
Resistant Bacteria ◽  
Phage Resistance ◽  
Lower Growth ◽  
Trade Offs

With rising antibiotic resistance, there has been increasing interest in the treatment of pathogenic bacteria with bacteriophages (phage therapy). One limitation of phage therapy is the ease at which bacteria can evolve resistance. The negative effects of resistance may be partially mitigated when resistance results in reduced bacterial growth and virulence, or when phage coevolve to overcome resistance. Resistance evolution and its consequences are highly contingent on the particular combination of bacteria and phage and the ecological context they interact in, making therapeutic outcomes hard to predict. One solution might be to conduct ″in vitro evolutionary simulations″ using the bacteria-phage combinations specific to the therapeutic context. Here, we investigate parallels between in vitro experiments and in vivo dynamics in a human participant. Evolutionary dynamics were similar in vivo and in vitro, with high levels of de novo resistance evolving quickly with limited evidence of phage evolution. Moreover, resistant bacteria – evolved both in vitro and in vivo – had lower virulence when measured in an insect model. In vivo, this was linked to lower growth rates of resistant isolates, whereas in vitro isolates evolved greater biofilm production with phage resistance. Population sequencing suggests resistance was typically the result of selection on de novo mutations rather than sorting of existing variants in the population. These results highlight the speed at which resistance to phages can evolve in vivo, and that in vitro evolution may give useful insights for evolutionary outcomes in vivo.

scholarly journals Determination of the optimal bacteriophage dose to control Pseudomonas aeruginosa using evolutionary programming and stochastic kinetics

2016 ◽  
Author(s):  
Diana C Ardila ◽  
Juan D Castro ◽  
Angela V Holguín ◽  
Viviana Clavijo ◽  
Catalina Prada ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Reverse Engineering ◽  
Pathogenic Bacteria ◽  
Phage Therapy ◽  
Evolutionary Programming ◽  
Stochastic Simulations ◽  
Resistant Bacteria ◽  
Multiple Drug ◽  
Promising Alternative

Phage-therapy is a promising alternative against pathogenic, multiple drug resistant bacteria. In this work we propose an algorithm to determine the optimal bacteriophage dose able to minimize a population of Pseudomonas aeruginosa. Reverse engineering was used to determine the kinetic parameters; subsequently, a bi-level optimization platform was implemented for a model based on evolutionary programming. Our prediction of optimal dose was tested in vitro with planktonic cultures of P. aeruginosa. From the data obtained, we conclude that reverse engineering and stochastic simulations are a useful approach to find optimal phage doses against pathogenic bacteria, an important step for the implementation of phage-therapy.

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